To see the other types of publications on this topic, follow the link: Rink.
Dissertations / Theses on the topic 'Rink'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Rink.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
NGUYEN, TUYET. "Carbon dioxide in ice rink refrigeration." Thesis, KTH, Tillämpad termodynamik och kylteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-118099.
Full textAbstract:
The average energy consumption of one ice rink is around 1000MWh/year, which approximately69% is occupied by the refrigeration unit and heating demand. With the aim of decreasing theenergy consumption, a new concept of refrigeration system with CO2 as a refrigerant has beendeveloped and it is promising to become a high potential next generation for refrigeration systemin ice rink.This thesis is to evaluate a new refrigerant application in ice rink refrigeration system underthree different aspects; energy performance, heat recovery potential and economic efficiency. Inorder to make this evaluation, three main tasks are executed. Firstly, literature review and marketstatistic are processed to give a general picture of the CO2 development as a refrigerant. Secondly, asoftware Pack Calculation II is used for the simulations of CO2 refrigeration system and traditionalice rink refrigeration system. Älta ice rink located in Sweden, is chosen as a reference case forsimulation’s input data. The simulation results is to compare these system in terms of energyperformance and heat recovery potential. Finally, life cycle cost of these systems is calculated toinvestigate the economic benefits from this new application.Results from this study show good benefits of the new CO2 application in ice rink. Fromthe market statistics, CO2 has become a successful refrigerant in supermarket food and beverageindustry with 1331 CO2 refrigeration system installed until 2011 in Europe (Shecco2012). In icerink industry, 24 ice rinks have been applied CO2 in the second cycle of refrigeration system; oneice rink in Canada applied a refrigeration system with only CO2 in the first cycle and the distributionsystem.From the simulation’s result, CO2 full system has been proven as the most efficiency sys-tem with the lowest energy consumption (30% lower than NH3/Brine system and 46% lower thanCO2/Brine system) and the highest COP (6.4 in comparison with 4.9 of NH3/Brine system and4.37 of CO2/Brine system). Regarding heat recovery potential, CO2 full system has highest energysaving in comparison with the other two systems.Due to lower energy cost and service cost, the life cycle cost of CO2 full system is loweraround 13% than the traditional NH3/Brine system, furthermore, the component cost of CO2 sys-tem is promising to decrease in the next years thanks to the rapid development of this market insupermarket industry.To conclude, CO2 full system has high potential to become a next generation of refrigerationsystem in ice rink, however, because of its transcritical working, this application can be restrictedin the regions of warm climate.
2
Kaya, Roni. "Energy Usage in Ice Rink Resurfacing." Thesis, KTH, Energiteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-212928.
Full textAbstract:
Ishallar kräver stora mängder energi för sin verksamhet. Undersökningar har visat att en typisk ishall i Sverige använder ca 1 000 MWh per år. Data från de mest effektiva ishallarna har visat att en väl utformad ishall kan nå en energiförbrukning på mindre än 500 MWh per år, vilket ger en stor potential för energisparande åtgärder. En statistisk studie av ett stort antal ishallar i Sverige har visat att kylsystemet har den största andelen av den totala energianvändningen i en ishall, motsvarande 43% i genomsnitt. Kylsystemets energianvändning är kraftigt beroende av olika värmebelastningar på isytan. Tidigare studier har fastställt andelarna i den totala värmebelastningen i ishallar som visat att de värmelaster som uppstår vid avspolning av isytan motsvarar mellan 14-17% av den totala värmelasten. I denna undersökning har spolvattnets volym och temperatur utvärderats med insamlad data genom experimentella mätningar och analyserats vidare med målet att bestämma andelen i totala värmbelastningen och föreslå energisparande åtgärder. Resultaten av studien bygger på data som samlats in i fem olika ishallar i Stockholm, och visar att de flesta fyllningar har en volym mellan 300-500 liter vid en temperatur mellan 30-50°C. Större volymer och högre temperaturer ökar värmebelastningen på isen genom latent och sensibel värme, vilket innebär att mindre volymer och lägre temperaturer minskar värmebelastningen och i sin tur energianvändningen. Undersökningen visar också att energiförbrukningen vid laddning av ismaskinerna varierar och pekar åt att förbrukningen ökar med äldre maskiner. Studien visar att genomsnittliga energiförbrukningen för de fem ishallarna vid en avspolning är 18 kWh i en hall med 100% värmeåtervinning (18% till laddning av ismaskin och 82% till kylsystemets kompressor) och 36 kWh utan värmeåtervinning (9% till laddning av ismaskin, 49% uppvärmning av spolvatten och 42% till kylsystemets kompressor), vilket indikerar en besparing i energiförbrukning genom integrerat värmeåtervinningssystem. Andelen av den totala värmelasten från mätningar visar att i genomsnitt 11% av totala värmebelastningen uppstår på grund av avspolningar. Resultaten har visat att vattentemperaturen vid utloppet av tanken skiljer sig avsevärt från fyllningstemperaturen. Detta innebär att den önskade spolvattentemperaturen skiljer sig från vad som faktiskt läggs på isen. I sin tur innebär det en stor energiförlust mellan 7 000-14 000 kWh / säsong för de undersökta ishallarna.Ice rink operations require significant amounts of energy. It has been concluded that a typical single sheet ice rink in Sweden uses around 1 000 MWh per year. Data from the most efficient ice rinks has shown that a well-designed ice rink could reach an energy usage of less than 500 MWh per year, which leaves a great potential for energy saving actions. A statistical study of a large number of ice rinks in Sweden has shown that the refrigeration system has the largest share of the total energy usage in an ice rink, corresponding to 43% in average. The energy consumption of the refrigeration system is depending on various heat loads on the ice surface. Previous studies has determined the shares of the total heat load in ice rinks, concluding that one of the four largest heat loads in an ice rink comes from the ice resurfacing, corresponding to 14-17%. Floodwater volume and temperature has been evaluated by collecting data through experimental measurements and further analysed with the goal to find energy saving actions. The results of the study are based on data collected in five different ice rinks in Stockholm, Sweden and shows that most fillings of resurfacing machines has a volume between 300-500 litres at a temperature between 30-50°C. Larger volumes and higher temperatures increase the heat load on the ice surface through latent and sensible heat, which means that smaller volumes and lower temperatures decrease the energy consumption. It has also been concluded that older resurfacing machines are larger energy consumers compared with newer models. The study shows that the energy consumption for an average resurfacing process 18 kWh with 100% heat recovery (18% from charging and 82% compressor electricity) and 36 kWh without heat recovery (9% from charging, 49% heating electricity and 42% compressor electricity), which indicates a decrease in energy consumption in ice rinks with heat recovery. The resurfacing share of the total heat loads from the measurements show that in average 11% of the heat load occurs by ice resurfacings. The results have shown that the water temperature at the outlet of the tank differs substantially from the filling temperature. This means that the desired floodwater temperature is different from what you actually get and there is a large waste in energy consumption for heating as the desired resurfacing temperature is rarely achieved. Studies show an approximate waste in energy consumption between 7 000 - 14 000 kWh/season.
3
Karampour, Mazyar. "MEASUREMENT AND MODELLING OF ICE RINK HEAT LOADS." Thesis, KTH, Tillämpad termodynamik och kylteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-61330.
Full textAbstract:
Ice rinks are among the most energy intensive public buildings in developed and developing countries. According to a research on Swedish ice rinks; a typical ice rink consumes approximately 1185 MWh/year which leads to more than 300 GWh/year for the 342 Swedish indoor ice rinks. The refrigeration system is usually the largest consumer by 43% average share of the total energy consumption. To decrease the refrigeration system energy demand, there are a variety of energy efficiency techniques known and available but the key to select the best ones is finding the major heat loads on the ice sheet and refrigeration system, which is unique for each ice rink. To fulfil this objective and in addition to review literature, this study has two main approaches. The first approach is to measure and evaluate the performance of the refrigeration system in two ice rinks, called Norrtälje and Älta. The estimated cooling capacity is approximately equal to the total heat load on the ice plus the heat gains in the distribution system. This goal has been accomplished by using a performance analyser called “ClimaCheck” which is based on an “internal method” because it uses the compressor as an internal mass flow meter and consequently, there is no need for an external one. The refrigerant mass flow rate is calculated by an energy balance over the compressor. By knowing the mass flow, enthalpy of the refrigerant, etc. the cooling capacity and COP of the system can be calculated. While the total heat load is known by the first approach, the second approach tries to discover different heat loads shares by analytical modelling. The measured physical and thermodynamical parameters plus the ice rink geometrical characteristics are input to the heat transfer correlations to estimate the heat load magnitude. The results of the measurements show that the total energy consumption in Norrtälje is about two third of Älta. The main reasons for this less energy consumption are smarter control systems for compressors and pumps, better ventilation distribution design and 1°C-2°C higher ice temperature. Analytical modelling for a sample day has estimated that about 84% of the total heat loads is originated from the heat loads on ice sheet while the distribution system causes the remaining 16%. Moreover, calculations show that convection plus small portion of condensation (altogether 36%), radiation (23%), ice resurfacing (14%) and lighting (7%) are the largest heat loads in winter while in summer condensation is another significant heat load (10%). Comparing two six-hour periods, one without ice resurfacing and four resurfacings in the second one, 30% more cooling demand has been calculated for the second period. Furthermore, it has been shown that the evaporator to brine is the contributor for 66% of the heat transfer resistances from ice to evaporator while brine to bottom ice and bottom to top ice accounts for 27% and 7% respectively. To conclude, a parallel “performance analysis of the refrigeration system” and “heat loads estimation” proves to be a useful tool for adopting proper design and control for energy efficient operation.Stoppsladd financed by Swedish Energy Agency (Energimyndigheten) and Swedish Ice Hockey Association
4
Thanasoulas, Sotirios. "Evaluation of CO2 Ice rink heat recovery system performance." Thesis, KTH, Energiteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-245233.
Full textAbstract:
Ice rinks are the largest energy consumers in terms of public buildings due to their simultaneous need of cooling, heating, ventilation, and lighting for different parts of the building which means that these facilities also have a lot of potential for energy saving. Due to the size of the cooling unit in an ice rink the refrigerant charge can become quite high, which potentially has a big impact on the environment. CO2 refrigeration units could cover all these challenges that are linked to ice rink operation. CO2 as a refrigerant has a very low impact on the environment and at the same time it could provide enough energy to cover the heating demands of an ice rink. CO2-based systems should operate in trans-critical mode which affects the performance of the refrigeration system, but by using the released heat that otherwise would be rejected to the ambience the total energy consumption becomes lower. The process of heat recovery is therefore vital for an efficient system. The refrigeration unit can produce enough energy to cover all the heating demands of an ice rink, but only when the heat recovery is controlled properly. The energy recovery method is very important, but it should also be tailored in order to cover all demands. This is because all the subsystems, i.e. demands, have different temperature and load requirements. The energy could be recovered in one or two stages from the refrigeration system. However, hardware is not enough in order to achieve proper operation, the system should also operate in the best conditions (discharge pressure and subcooling) in order to be efficient. The more proper operation, the less energy consumption. This energy recovery method could also be used as subcooling in climates where the ambient temperature is very high, making CO2 a very efficient solution. Regular refrigerants are still often used in warm countries despite their high environmental impact. A refrigeration system using natural refrigerants and more specific CO2 does not have constraints, however. The only limitation is the wrong operation.Isrinkar är de största energikonsumenterna när det gäller offentliga byggnader på grund av deras ständiga behov av nedkylning, uppvärmning, ventilation och belysning. Detta innebär också att anläggningarna har en stor potential att effektivisera sin energibesparing. Isrinkar konsumerar stora mängder kylmedel på grund av deras storlekar, vilket potentiellt har en stor negativ inverkan på miljön. CO2 kylenheter skulle kunna klara av alla dessa utmaningar som är kopplade till isrinkens drift. Att använda CO2 som en kylarvätska har en ytterst liten inverkan på miljön och kan dessutom bidra med tillräckligt mycket energi för att täcka uppvärmningsbehovet för en isrink. CO2 baserade system bör köras i ett transkritiskt läge vilket påverkar kylsystemets prestanda, men genom att återanvända den utsläppta värmen som annars skulle gå förlorad till omgivningen så blir den totala energiförbrukningen lägre. Värmeåtervinningsprocessen är därför avgörande för ett effektivt energisystem. Kylaggregatet kan producera tillräckligt med energi för att täcka alla värmebehov för en isrink, men endast när värmeåtervinningen behärskas ordentligt. Energiåtervinningsmetoden är också väldigt viktig, men den bör skräddarsys för att täcka alla krav. Detta beror på att alla delsystem, dvs krav, har olika temperatur- och belastningskrav. Energin kan återvinnas i ett eller två stadier från kylsystemet. Tyvärr så räcker dock inte hårdvaran till för att uppnå en önskad drift, men systemet bör även fungera under de bästa förutsättningarna (utloppstryck och underkylning) för att vara effektiv. Ju bättre drift, desto mindre är energiförbrukningen. Denna energiåtervinningsmetod kan också användas som underkylning i varma klimat vilket gör CO2 till en mycket effektiv lösning. Vanliga typer av kylmedel används fortfarande ofta i varma länder trots att deras negativa miljöpåverkan. Ett kylsystem med ett naturligt kylmedel som till exempel koldioxid har emellertid inga begränsningar. Den enda begränsningen är den felaktiga hanteringen av driften.
5
Kilberg, Brianna. "Aqua Ammonia as Secondary Fluid in Ice Rink Applications." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-281954.
Full textAbstract:
Refrigerant management is crucial in the attempts to slow climate change. Emissions from the refrigeration sector are primarily due to poor management and unsafe destruction of refrigerants currently in circulation. Safe refrigerant management and improving system operating efficiency can result in a reduction of emissions. Ice rinks are some of the most energy-intensive public buildings, providing both heating and cooling. The major share of energy in an ice rink is the refrigeration system, which consumes about 43%. There are more than 360 ice rinks in Sweden as of 2018 and the most common type of refrigeration system is an indirect system. With the push for natural fluids, aqua ammonia is becoming a more appealing option as a secondary fluid in ice rinks because of its minimal negative impact on the environment and favorable thermophysical properties. The main drawbacks of the fluid are its toxic characteristics and material compatibility. However, since the first use in 2007, there has been an increase to 34 of the total ice rinks in Sweden that have aqua ammonia as a secondary fluid. Thermophysical properties are used to calculate refrigeration design parameters, including secondary fluid concentration and pumping power required. The properties of aqua ammonia have not been experimentally tested within this century to the extent presented in this thesis. Existing data is either derived from measured values taken several decades ago or has been calculated. The novelty of this thesis project stems from the unique and more accurate results measured through laboratory work and from the ability to determine the impact of the newly measured values in ice rink refrigeration design. A total of 11 varying concentrations of aqua ammonia were tested for density, dynamic viscosity, specific heat capacity, thermal conductivity, and corrosion of 7 metal specimens. The solutions tested ranged from 2 wt-% to 30 wt-%, correlating to freezing points from -2C to -84C. The measurements for density resulted in values similar to reference values, ranging in a difference of only 0.3% to 1.7%. Dynamic viscosity results followed nearly the same trend as references with changing temperature and solution concentration, with values varying from 0.8% to 17% different than references. Specific heat capacity measurements proved significantly different than reference values. The trend is opposite of the reference, leading to drastically different values, especially at lower temperatures and higher solution concentrations. The difference in values ranges from 0.1% to 28%. Thermal conductivity results show similar trends, but higher values than expected. The difference between measured values and reference values range from 0.1% to 13%. Corrosion results show that copper and brass have the highest corrosion rates of 16.2 mm/yr and 1.84 mm/yr, respectively. The most compatible specimen was stainless steel, followed by carbon steel, with maximum corrosion rates of 0.041 mm/yr and 0.11 mm/yr, respectively. Brass connections commonly used in industry were also tested and resulted in corrosion rates ranging from 69.6 g/yr to 112 g/yr, which accounts for about 1% and 1.5% of the connections’ total weight lost per year. Compiling the laboratory measurements taken during the completion of this thesis project results in a more complete and accurate list of thermophysical properties for aqua ammonia that has never existed before. These updated thermophysical properties for aqua ammonia, along with measured properties for other secondary fluids, were used to calculate operational parameters in a hypothetical ice rink refrigeration system. The results show that aqua ammonia is favorable with high COP and low pumping power, and therefore low pressure drop. Ammonia is most comparable to CaCl2 and K-formate for most results. The changes in calculated COP between old reference data and new measured data were less than a 1% decrease when plotting versus the temperature of the ice surface and with a set pump control (T) for cooling capacities of 200kW and 300kW. The change in heat transfer coefficients was more significant, with a range of about a 9% to 27% decrease in either the U-pipe under the rink floor or in a plate of the heat exchanger. Even though these heat transfer coefficient values are lower than previously calculated, the required pumping power is also lower using updated properties: 40% lower at a secondary fluid temperature of -10C. Even though the change in heat transfer coefficients is larger with experimental values, the impact on COP is minimal. The takeaway from this project is that aqua ammonia is a favorable secondary fluid compared to calcium chloride and ethylene glycol, the two most commonly used secondary fluids in ice rink refrigeration. A system using aqua ammonia would have a 45% and 47% lower pumping power requirement compared to calcium chloride and ethylene glycol, respectively. The system would also have a 4.7% and 11.6% higher COP when compared to systems with calcium chloride and ethylene glycol, respectively. The significantly lower pumping power will lower total energy demand of the ice rink, thus decreasing operation costs.Köldmediehantering är avgörande i försöken att sakta ner klimatförändringen. Utsläppen från kylsektorn beror främst på dålig hantering och osäker destruktion av köldmedier som för närvarande är i omlopp. Säkrare hantering av köldmedium och förbättrad systemdriftseffektivitet kan leda till ett minskat utsläpp. Ishallar är några av de mest energiintensiva offentliga byggnaderna som ger både uppvärmning och kylning. Den största andelen energi i en ishall är kylsystemet som förbrukar cirka 43%. Det finns mer än 360 isbanor i Sverige från och med 2018 och den vanligaste typen av kylsystem är ett indirekt system. Med trycket på naturliga vätskor blir ammoniakvatten ett mer tilltalande alternativ som en köldbärare i ishallar på grund av dess minimala negativa påverkan på miljön och gynnsamma termofysikaliska egenskaper. Köldbärares främsta nackdelar är dess toxiska karaktär och materialkompatibilitet. Sedan den första användningen 2007 har det dock skett en ökning till 34 av de totala ishallar i Sverige som har ammoniakvatten som köldbärare. Termofysikaliska egenskaper används för att beräkna parametrar för kyldesign, inklusive köldbärares koncentration och pumpeffekten som krävs. Ammoniakvattens egenskaper har inte testats experimentellt under detta sekel i den utsträckning som presenteras i detta exjobb. Befintliga data härleds antingen från uppmätta värden som tagits för flera decennier sedan eller har beräknats. Nyheten härrör i detta exjobbsprojekt från de unika och mer exakta resultat som mätts genom laboratoriearbetet och från förmågan att bestämma effekten av de nyligen uppmätta värdena i kylskåpsdesign. Totalt 11 olika koncentrationer av ammoniakvatten testades med avseende på densitet, dynamisk viskositet, specifik värmekapacitet, värmeledningsförmåga och korrosion av 7 metallprover. De testade lösningarna varierade från 2 vikt-% till 30 vikt-%, korrelerade med fryspunkter från -2 ° C till -84 ° C. Mätningarna för densitet resulterade i värden som liknar referensvärdena, med en skillnad på endast 0,3% till 1,7%. Dynamiska viskositetsresultat följde nästan samma trend som referenser med förändrad temperatur och lösningskoncentration, med värden som varierade från 0,8% till 17% annorlunda än referenser. Specifika värmekapacitetsmätningar visade sig vara väsentligt annorlunda än referensvärden. Trenden är motsatt referensen, vilket leder till drastiskt olika värden, särskilt vid lägre temperaturer och högre koncentrationer. Skillnaden i värden varierar från 0,1% till 28%. Värmeledningsförmåga visar liknande trender, men högre värden än förväntat. Skillnaden mellan uppmätta värden och referensvärden sträcker sig från 0,1% till 13%. Korrosionsresultat visar att koppar och mässing har de högsta korrosionshastigheterna på 16,2 mm / år respektive 1,84 mm / år. Det mest kompatibla exemplet var rostfritt stål, följt av kolstål, med maximala korrosionshastigheter på 0,041 mm / år respektive 0,11 mm / år. Mässinganslutningar som vanligen används i industrin testades också och resulterade i korrosionshastigheter från 69,6 g / år till 112 g / år, vilket motsvarar för cirka 1% och 1,5% av anslutningarnas totala viktförlust per år. Att sammanställa laboratoriemätningarna som gjorts under slutförandet av detta projekt resulterar i en mer fullständig och noggrann lista över termofysikaliska egenskaper för ammoniakvatten som aldrig funnits tidigare. Dessa uppdaterade termofysikaliska egenskaper för ammoniakvatten, tillsammans med uppmätta egenskaper för andra köldbärare, användes för att beräkna driftsparametrar i ett hypotetiskt kylsystem. Resultaten visar att ammoniakvatten är gynnsam med hög COP och en låg pumpeffekt och därmed ett lågt tryckfall. Ammoniakvatten är mest jämförbart med CaCl2 och K-formiat för de flesta resultat. Förändringarna i beräknad COP mellan gamla referensdata och nya uppmätta data var mindre än 1% minskning vid planering jämfört med isytans temperatur och med en inställd pumpkontroll (T ) för kylkapacitet på 200 kW och 300 kW. Förändringen i värmeövergångstal var mer signifikant, med ett intervall på cirka 9% till 27% minskning i antingen U-röret under golvet eller i en platta på värmeväxlaren. Även om dessa värmeövergångstal är lägre än tidigare beräknat, är den erforderliga pumpeffekten också lägre med hjälp av uppdaterade egenskaper: 40% lägre vid en köldbärarestemperatur på -10 ° C. Även om förändringen i värmeövergångstal är större med experimentella värden, är påverkan på COP minimal. Slutsatser från detta projekt är att ammoniakvatten är en lämplig köldbärare jämfört med kalciumklorid och etylenglykol, de två vanligaste köldbärare i ishallskylning. Ett system som använder ammoniakvatten skulle ha ett pumpeffektbehov på 45% respektive 47% jämfört med kalciumklorid respektive etylenglykol. Systemet skulle också ha en 4,7% och 11,6% högre COP jämfört med system med kalciumklorid respektive etylenglykol. Den betydligt lägre pumpeffekten kommer att sänka det totala energibehovet för ishallar, vilket minskar driftskostnaderna.
6
Li, Zhenji. "Study of superconductivity based on the Nozieres-Schmitt-Rink Formalism." 京都大学 (Kyoto University), 2001. http://hdl.handle.net/2433/150814.
Full text
7
Giller, Lisa Konstanze [Verfasser], Thomas [Akademischer Betreuer] [Gutachter] Rink, and Thomas [Gutachter] Vogl. "β-HCG-induzierte Hyperthyreose in der Schwangerschaft - Vermeidung von Fehlinterpretationen im Rahmen von Vorsorgeuntersuchungen / Lisa Konstanze Giller ; Gutachter: Thomas Rink, Thomas Vogl ; Betreuer: Thomas Rink." Frankfurt am Main : Universitätsbibliothek Johann Christian Senckenberg, 2017. http://d-nb.info/1136368132/34.
Full text
8
Igual, Bueno Mario, and Azcona Jose Enrique Bielsa. "ANALISYS AND ENERGY SAVING MEASURES OF KASTVALLEN ICE HOCKEY RINK ARENA." Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-12349.
Full textAbstract:
Nowadays efficiency measures are more and more important because the price of the energy is increasing every year. Moreover, saving energy it is also important for decrease the environmental impact. Kastvallen is a hockey arena built in 1997 that cools the hockey rink with electric compressors. The changing rooms are heating by using district heating. Actually the total invoice of electricity is above the 800000 SEK. Meanwhile the district heating invoice reaches the 60000SEK. The aim of this project is reducing the amount of the electricity and heat invoice promoting smart energy improvements. The improvements proposals can be divided in three sections; energy savings of the changing rooms, efficiency increase of the compressors and dehumidifier energy savings. For heat the tap water and the changing room’s ventilation it is suggested to take profit from the heat released at the condenser and so reduce its heat load requirements. For this proposal two different configurations are studied. In order to increase the efficiency of the compressors the possibility of reducing the condenser temperature will be studied. Three proposals will be studied to carry out this commitment; Installing a condensing temperature control, installing a evaporate cooler and having a snow storage. Finally, one of the largest consumers of electricity in Kastvallen ice hockey rink is the dehumidifier. The current dehumidifier works with a desiccant wheel. The desiccant material extract the moisture from the processed air flow, after that the desiccant has to be reactivated with ‘fresh air’. This reactivation air needs to be heated 95ºC, so the waste air released after the reactivation of the desiccant is air at high temperature. The first proposal is preheat the reactivation air with the hot waste air in order to reduce the heating requirements, conducting this proposal the total money saved each year would be 41811 SEK with a Pay-back around 1 year. The second step is studied the possibility of heating the air with district heating, taking into account that district heating is three times cheaper than electricity, conducting this proposal the total money saved each year would be 45629 SEK with a Pay-back around 1 year. The last proposal is to combine preheating and heating with district heating, conducting this proposal the total money saved each year would be 61553 SEK with a Pay-back around 1.6 years. All the previous energy improvements proposals are studied with empirical and analytical methods and using the knowledge gained during the previous years of studies. The study concludes that the best proposal for the dehumidifier is combine the preheating and heating with district heating. In addition of the money saved, this measure allows to save 2.71 Tm of CO2 each year. For the refrigeration cycle, the study concludes that installing a controlled temperature control is the best option if the price of that is lower than 334726 SEK. If not the best option is heating the rooms and the ventilation with the condenser of the refrigeration cycle. These measures could reduce between 8% and 20% of the total energy invoice plus a considerable reduction of CO2 emissions. Evaporative cooling and snow storage would be studying after with the data of the first year of the condensing temperature control; if it is installed.
9
BERG-LUNDFELDT, EMIL. "Field Measurements and Modelling Analysis of Integrated Ice Rink Energy Systems." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-280370.
Full textAbstract:
Behrn Arena in Örebro, Sweden, is an ice rink facility where the company is interested in ways of improving their current energy system in terms of energy efficiency. Currently, district cooling is purchased to reclaim the waste heat from the ice rink refrigeration system, which is further used as a heat source for local district heating distributor. In return, the cost of district heating is reduced. A techno-economic analysis was conducted where the current refrigeration and heating system in Behrn Arena was compared to three different scenarios. These were defined as the current refrigeration system with improved performance, the most common ice rink heating and refrigeration system in Sweden, and an ice rink with a trans-critical CO2-refrigeration system with heat recovery. Furthermore, alternatives to how the reclaimed heat may be utilized were investigated from an economic point of view. This included using the heat internally in the facility or selling the heat to a district heating distributor. From this study it was concluded that the current refrigeration system using district cooling as a heat sink, with the cost reductions, had a lower cost of operation relative to the typical ice rink in Sweden. Furthermore, a CO2-refrigeration system running in trans-critical operating conditions with two-stage heat recovery has potential of reducing the seasonal cost of energy of the current system with regards to heating and cooling by approximately 50 %. At the same time the heating demand coverage will be up to 89.5 %. Finally, selling heat to a district heating distributor proved to be unfavourable from a prosumer perspective if the waste heat could be utilised internally by the facility.Behrn Arena i Örebro är en isrinkanläggning där intresse från fastighetsägaren finns för att förbättra det nuvarande energisystemet för ökad energieffektivitet. Det nuvarande systemet återvinner spillvärmen från kylaggregaten via det lokala fjärrkylanätet genom att anläggningen köper fjärrkyla. Spillvärmen används sedan som värmekälla för en värmepump som vidare distribuerar fjärrvärme. Ersättningen för att köpa fjärrkylan är en prissänkning av vad fastighetsägaren betalar för fjärrvärme. En teknoekonomisk analys genomfördes med syfte att jämföra det nuvarande kyloch värmesystemet med tre olika scenarier. Dessa definierades som en mer energieffektiv version av det nuvarande kylsystemet, det vanligaste kyl- och energisystemet för isrinkar i Sverige samt ett system för transkritiskt CO2 och värmeåtervinning i två steg. Därtill undersöktes olika alternativ för hur spillvärmen kan användas, till exempel genom att använda den internt eller sälja den till en fjärrvärmesdistributör. Från denna studie framkom det att det nuvarande kylsystemet med fjärrkyla som värmesänka, inklusive kostnadsreduktionen av fjärrvärme, hade en lägre driftkostnad jämfört med den typiska isrinken i Sverige. Därutöver finns potential att reducera driftenergikostnaden av det nuvarande energisystemet med avseende på kyla och värme med cirka 50 % genom att nyttja ett kylsystem med värmeåtervinning i två steg och en transkritisk kylcykel med CO2. Samtidigt uppgår täckningen av värmebehovet till 89,5 %. Slutligen framkom det att sälja spillvärme till en fjärrvärmedistributör är ekonomiskt ofördelaktigt om det finns ett värmebehov inom fastigheten.
10
Rink, Kristian [Verfasser], and Peter [Akademischer Betreuer] Bachert. "Signal-verstärkte multispektrale In-vivo-31P-Magnetresonanztomographie / Kristian Rink ; Betreuer: Peter Bachert." Heidelberg : Universitätsbibliothek Heidelberg, 2016. http://d-nb.info/1180615174/34.
Full text
11
Fahlén, Josef. "Structures beyond the frameworks of the rink : On organization in Swedish ice hockey." Doctoral thesis, Umeå universitet, Pedagogik, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-734.
Full textAbstract:
This is a dissertation on organization in Swedish ice hockey based on four articles. The purpose of the thesis is to contribute knowledge on the direction, management and practice of sport using Swedish elite ice hockey as an example. Knowledge is created by examining four separate but mutually contingent aspects of organizations. Article I contributes to the overall purpose with knowledge on the professionalization of Swedish ice hockey, the reasons behind and the consequences of it. Focusing on the timeframe 1967-2000 the article highlights how norms, values and ideals changed over time and contributed to a change from ice hockey as an amateur sport based on idealistic motives and volunteer efforts to a professional sport based on entertainment and commercial forces. Article II contributes knowledge on the structural organization of Swedish elite ice hockey clubs and contributing factors. The article compares eleven elite ice hockey clubs and shows how they vary in relation to each other from low to high specialization, standardization and centralization but also how they present many similar characteristics such as organizational form, subsidiary businesses, cooperation with farm clubs and upper secondary schools, types of employments and division of workload. Article III contributes with knowledge on how organizational structures are experienced by individuals working or volunteering in the clubs. Comparing experiences in two structurally different clubs, the article shows how more developed structures are experienced more positively than less developed structures are. However, both groups agree that more developed structures are desirable and they also have similar opinions on issues concerning formal education and training, the elite program vs. the youth program, strategic vs. operative tasks and personal freedom. Article IV contributes knowledge on how experiences of mentioned structures are affected by remuneration, authority and centrality. Exploring four positions differing from each other with regard to hierarchical position, distance to the club’s core activities and payment, the article shows that individual experiences of organizational structure vary depending on where in the club the individual works. This variation is shown to result in tensions between the different positions. The knowledge offered in the thesis is based on three data collections. Data have been gathered from official and unofficial documentation from and on the Swedish sports confederation, the Swedish ice hockey association and 11 clubs represented in the highest division 2000/2001, and from individuals working or volunteering in these clubs as board members, general managers, marketing assistants, coaches, volunteers in the youth programs and arena personnel. The studies are carried out within an institutional theory framework and the analysis of the results taken together shows how the structures in elite ice hockey clubs are affected by surrounding environment and societal environments. Norms and ideals concerning legitimate ways of organizing are mediated by authorities, educational establishments, trade organizations and successful models in neighbouring industries. These norms and ideals have changed as new actors such as television networks, commercial sponsors and employed staff have entered ice hockey and as the roles of the government, the associations, the coaches and the players have changed. These ongoing changes are combining to a new context and new circumstances for the direction, management and practice of Swedish ice hockey.
12
Fahlén, Josef. "Structures beyond the frameworks of the rink : on organization in Swedish ice hockey /." Umeå : Department of Education, Umeå University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-734.
Full text
13
Kloubert, Veronika [Verfasser], Lothar [Akademischer Betreuer] Rink, and A. J. [Akademischer Betreuer] Slusarenko. "Einfluss von Zink auf die Zytokingenregulation / Veronika Kloubert ; Lothar Rink, A. J. Slusarenko." Aachen : Universitätsbibliothek der RWTH Aachen, 2018. http://d-nb.info/1181109124/34.
Full text
14
Rink, Anna [Verfasser]. "Der Präventionsauftrag der gesetzlichen Unfallversicherung. : Verfassungs- und europarechtliche Vorgaben für Präventionsmaßnahmen. / Anna Rink." Berlin : Duncker & Humblot, 2010. http://d-nb.info/1238423744/34.
Full text
15
Dietz, Mike. "Development of techniques and procedures for evaluating ice quality in ice rink applications." Thesis, KTH, Energiteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-200967.
Full textAbstract:
Denna rapport presenterar de kritiska parametrarna inom isproduktion, en utvärdering av dessa samt dess inflytande på isens kvalitet. För isens kvalitet är syftet att finna objektiva kriterier för vad som är bra eller dåligt, föreslåolika metoder för att utvärdera dem samt vilken typ av vattenbehandling som kan vara till nytta.När man talar om iskvalitet tänker de flesta människor på isens hårdhet som en del av det och det är den som mest beskrivna och diskuterade egenskapen. Förutom detta är även isens och vattnets mineralinnehåll, mängden av innesluten luft, temperatur, mängden producerad snö, samt transparens. Många parametrar som alla är kopplade till isens hårdhet. Antingen påverkar de isens hårdhet eller påverkas av den.Testerutfördes huruvida vattnets elektriska ledningsförmågan påverkar isens elektriska ledningsförmåga. Syftet var att kontrollera om mineralinnehållet i isen kan mätas på ett snabbt och enkelt sätt utan att behöva ta prover, smälta snön och sedan mäta vatten-konduktiviteten bara genom att använda en anordning för att mäta isytans ledningsförmåga. En korrelation mellan de två värdena kunde visas även om variansen mellan de olika testkörningarna var ganska hög.Därefter togs prover från ishallar för att bestämma korrelationen mellan mineralinnehållet i det utspillda kranvattnet och mineralinnehållet på isytan. Mot antagandet att färre mineraler i vattnet skulle leda till ett lägre mängd på isytan, kan en direkt korrelation inte fastställas. Även på samma isbana var skillnaderna mycket högt.Vid provning av inverkan av mineralhalten i vattnet på isens hårdhet kunde endast en liten negativ korrelation fastställas. Resultatet bör inte värderas för högt, eftersom provningsmetoden kunde ha varit olämpligt.Baserat på alla testresultat kan ingen förbättring av iskvaliteten förväntas vid avsaltning av vattnet som förbehandling. På andra sidan, att sprida varmvatten vid nytillverkning av is verkar ha ett högre inflyttande och leder till mycket bättre resultatThis report is about to find crucial parameters in the ice making process, evaluate them and determine their influence on the ice quality. For the ice quality it is supposed to find objective criteria what is good or bad and propose methods to evaluate them objectively and what kind of water treatment could be useful.When speaking about ice quality most people have ice hardness at a part of it in mind and it is the most described and discussed property as well. Then there is the mineral content in the ice and water, amount of trapped air, temperature, amount of produced snow, transparency. A lot of parameters that are all linked to the ice hardness. Either they influence the ice hardness or are influenced by it.Test if the electric conductivity of the water influences the electric conductivity of the ice have been made. The aim was to check if the mineral content of the ice can be measured in a fast and easy way without having to take samples, melting the snow and then measure the water conductivity just by using a device to measure the ice surface conductivity. A correlation between the two values could be shown even though the variance between the different test runs was quite high.Then samples from ice rinks have been taken to determine the correlation between mineral content in the spilled tap water and the mineral content at the ice surface. Against the assumption that fewer minerals in the water would lead to a lower amount at the ice surface, a direct correlation could not be ascertained. Even in the same ice rink the differences were very high.When testing the influence of the mineral content in the water on the ice hardness just a small negative correlation could be determined. The results should not be valuated too high, because the test method could have been unsuitable.Concluding all the results an improvement of the ice quality is not expected when desalinating the water as a pre-treatment. Spilling hot water when resurfacing the ice seems to have a higher influence and lead to much better results.
16
Rink, Jürgen [Verfasser]. "Dopplerreduzierende laserspektroskopische Methoden an gespeicherten Ionen zur Bestimmung der Isotopieverschiebung von Hafnium / J. Rink." Karlsruhe : KIT-Bibliothek, 1992. http://d-nb.info/1153058898/34.
Full text
17
Pappas, Nicholas Todd. "On the ice and off the rink : a qualitative study of hockey players' aggression." The Ohio State University, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=osu1260638431.
Full text
18
Debes, Maik [Verfasser], Jochen [Akademischer Betreuer] Seitz, Günther [Akademischer Betreuer] Schäfer, and Wolfram [Akademischer Betreuer] Rink. "Konzeption und Realisierung eines kontextsensitiven Routingverfahrens / Maik Debes. Gutachter: Günther Schäfer ; Wolfram Rink. Betreuer: Jochen Seitz." Ilmenau : Universitätsbibliothek Ilmenau, 2010. http://d-nb.info/100939939X/34.
Full text
19
Rink, Christian [Verfasser]. "Integration von Lieferanten in die frühe Phase des Innovationsprozesses : Erfolgswirkung, Determinanten und moderierende Effekte / Christian Rink." Aachen : Shaker, 2008. http://d-nb.info/1161306463/34.
Full text
20
Rink, Ina [Verfasser], Katja [Akademischer Betreuer] Schmitz, Harald [Akademischer Betreuer] Kolmar, and Antal [Akademischer Betreuer] Rot. "Untersuchungsmethoden für die chemokininduzierte Migration von Leukozyten / Ina Rink. Betreuer: Katja Schmitz ; Harald Kolmar ; Antal Rot." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2016. http://d-nb.info/1112269460/34.
Full text
21
Reiter, Jana Verfasser], Alan [Akademischer Betreuer] [Slusarenko, and Lothar [Akademischer Betreuer] Rink. "Die Untersuchung von Allicin aus Knoblauch als Alternative zu konventionellen Antibiotika / Jana Reiter ; Alan Slusarenko, Lothar Rink." Aachen : Universitätsbibliothek der RWTH Aachen, 2020. http://d-nb.info/1216175799/34.
Full text
22
Maywald, Martina [Verfasser], Lothar [Akademischer Betreuer] Rink, and Jürgen [Akademischer Betreuer] Bernhagen. "Zinc Supplementation Induces Regulatory T Cells in vitro and in vivo / Martina Maywald ; Lothar Rink, Jürgen Bernhagen." Aachen : Universitätsbibliothek der RWTH Aachen, 2017. http://d-nb.info/1162499184/34.
Full text
23
Rink, Christian [Verfasser], and Martin E. [Akademischer Betreuer] Maier. "Zearalenon-Analoga als Hsp90-Inhibitoren sowie Studien zur Synthese von Leiodermatolid / Christian Rink ; Betreuer: Martin E. Maier." Tübingen : Universitätsbibliothek Tübingen, 2011. http://d-nb.info/1162699000/34.
Full text
24
Reiter, Jana [Verfasser], Alan [Akademischer Betreuer] Slusarenko, and Lothar [Akademischer Betreuer] Rink. "Die Untersuchung von Allicin aus Knoblauch als Alternative zu konventionellen Antibiotika / Jana Reiter ; Alan Slusarenko, Lothar Rink." Aachen : Universitätsbibliothek der RWTH Aachen, 2020. http://d-nb.info/1216175799/34.
Full text
25
Rink, Claudia [Verfasser]. "Autoantikörper gegen Proteine monaminerger Systeme beim Guillain-Barré Syndrom - mögliche Beteiligung an der Pathophysiologie des Psychosyndroms? / Claudia Rink." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2011. http://d-nb.info/1026265029/34.
Full text
26
Rink, Christian [Verfasser]. "Die Pflicht zur Teilnahme am ärztlichen Bereitschaftsdienst. : Eine verfassungsrechtliche Kritik der Bereitschaftsdienstordnungen von Ärztekammern und Kassenärzlichen Vereinigungen. / Christian Rink." Berlin : Duncker & Humblot, 2020. http://d-nb.info/1238491499/34.
Full text
27
Makhnatch, Pavel. "Technology and Energy Inventory of Ice Rinks." Thesis, KTH, Tillämpad termodynamik och kylteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-34791.
Full textAbstract:
Currently 341 ice rinks are in operation in Sweden with an estimated total energy consumption of 384 GWh/year. As it has been revealed in previous studies, most of the ice arenas are constructed and/or not operated efficiently. Thus it is considerable energy saving potential, which could be achieved in this area. The potential is even more significant if one can consider the savings in the ice rinks all over the world. This report is an in-depth study, which aims at analysing the Swedish ice rinks energy consumption and estimation of the corresponding energy saving potential. The report analyses the energy statistics obtained through the Stoppsladd study, which includes the ice rinks inventory, data collection and compilation of energy relevant data for 100 ice rinks located in Sweden. The inventory has revealed a number of important statistical figures, such as total energy consumption average in total (estimated to be 1,137 MWh/year) and for different ice arenas categories in particular. Relevant specific energy consumption values as well as a number of other important figures are also provided in the paper, thus giving an idea on the way to minimise energy consumption at each specific ice rink. The results are additionally supported by statistical multifactor regression analysis, which resulted in a relation between the ice rink’s total energy consumption and some known factors values affecting it. Two in-depth studies fulfil the Stoppsladd project by analysing water quality and ice quality effect on the ice rink’s energy consumption and investigation of the static and dynamic heat flow distribution in ice rink slab. A static heat flow distribution model of an ice rink evaluated the effect of concrete with different properties on temperature and heat flow distribution within an ice rink floor slab. The study proves that the ice rink refrigeration system COP2 could be increased with 3.5 % just implementing new high thermal conductivity concrete layer into the conventional concrete ice rink floor. The static analysis results were further completed with dynamic analysis, which adequately reflects the thermodynamic response of the concrete ice rink floor to a varying heat load. As a result, the thesis represents a holistic approach to the ice rink energy efficiency increase problem and provides a good basis for further studies in relevant areas. It is proved that modified concrete allowing higher (efficient) secondary refrigerant temperatures and also provides better response to change in heat load to the system.Stoppslad
28
Dickmann, Johanna [Verfasser], Christian [Gutachter] Dahmann, Frank [Gutachter] Jülicher, Frank [Akademischer Betreuer] Jülicher, and Jochen [Akademischer Betreuer] Rink. "Formation of long-ranged morphogen gradients by cell-to-cell relay / Johanna Dickmann ; Gutachter: Christian Dahmann, Frank Jülicher ; Frank Jülicher, Jochen Rink." Dresden : Technische Universität Dresden, 2021. http://d-nb.info/123191730X/34.
Full text
29
Frank, Olga [Verfasser], Richard [Gutachter] Roy, Francis [Gutachter] Stewart, and Jochen C. [Akademischer Betreuer] Rink. "Energy Metabolism and the Control of Stem Cell Proliferation in Planarians / Olga Frank ; Gutachter: Richard Roy, Francis Stewart ; Betreuer: Jochen C. Rink." Dresden : Technische Universität Dresden, 2020. http://d-nb.info/1227202261/34.
Full text
30
Schmitz, Birte Katharina Verfasser], Lothar [Akademischer Betreuer] Rink, Markus [Akademischer Betreuer] Kipp, and Marc [Akademischer Betreuer] [Spehr. "Cortical pathologies and astrocyte heterogeneity in rodent models of multiple sclerosis and Parkinson’s disease / Birte Katharina Schmitz ; Lothar Rink, Markus Kipp, Marc Spehr." Aachen : Universitätsbibliothek der RWTH Aachen, 2020. http://d-nb.info/1225878780/34.
Full text
31
Rink, Nadine [Verfasser], Martin [Akademischer Betreuer] Klingenspor, Hannelore [Gutachter] Daniel, and Martin [Gutachter] Klingenspor. "Kandidatengene für Adipositas : Einfluss von Adipositas-Genen auf Komponenten des Energiehaushalts der Labormaus / Nadine Rink ; Gutachter: Hannelore Daniel, Martin Klingenspor ; Betreuer: Martin Klingenspor." München : Universitätsbibliothek der TU München, 2018. http://d-nb.info/116631507X/34.
Full text
32
Schmitz, Birte Katharina [Verfasser], Lothar Akademischer Betreuer] Rink, Markus [Akademischer Betreuer] Kipp, and Marc [Akademischer Betreuer] [Spehr. "Cortical pathologies and astrocyte heterogeneity in rodent models of multiple sclerosis and Parkinson’s disease / Birte Katharina Schmitz ; Lothar Rink, Markus Kipp, Marc Spehr." Aachen : Universitätsbibliothek der RWTH Aachen, 2020. http://d-nb.info/1225878780/34.
Full text
33
Gummesson, Patrik. "Evaluation of heat pump concepts in ice rinks." Thesis, KTH, Tillämpad termodynamik och kylteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-141149.
Full textAbstract:
In Sweden there are about 350 ice rinks in operation today which consume approximately 300 GWh per year. The average energy consumption for a Swedish ice rink is approximately 1000 MWh per year. Ice rink dose not only consume energy it also rejects heat. The rejected heat comes from the refrigeration system that cools down the ice floor. The refrigeration system rejects heat around 700 to 1000 MWh per season. The reason for this study is because of the rejected heat which leads to the question how the rejected heat can be used.The object is to find a heat pump concept that can use the rejected heat or another heat source in an ice rink. Three different heat pump concepts were evaluated. The first heat pump concept use the ice floor as a heat source (called BHP), the second concept use the rejected heat as a heat source (called CHP) and the third concept use the rejected heat to charge an energy storage (called GHP).To accomplish the objective a heat analysis of two ice rinks were made to be able to simulate the heat pump concepts. With the simulation results a life cycle cost was made for a better evaluation. The results from the heat analysis were used for simulating the heat pump concepts. The two ice rinks that were analyzed were Järfälla ice rink and Älta ice rink. The main heat source the two ice rinks uses today is district heating and electricity. Järfälla only use district heating (DH) as a heat source and Älta ice rink use recovery heat, electricity and district heating.The heat analysis of the two the ice rinks showed that the highest district heating consumer was the domestic hot water at 47% of the DH followed by the dehumidifier at 32% of the DH and last the space heating at 22% of the DH. This shows how the heat is used in a general ice rink in Sweden. The temperature levels for the dehumidifier is around 65 °C (only DH part), the domestic hot water at 55 °C and last the space heating at 20 °C. However the heat demand for the ice rinks resulted in 443 MWh for Järfälla and 192 MWh for Älta. To know the size of the heat pump used for the heat pump concepts a heat profile for the ice rinks were made. The result of heat profiles lead to a heat pump size of 105 kW in Järfälla and 45 kW in Älta. The rejected heat for one season in Järfälla is 1000 MWh and 780 MWh in Älta.With the results from the heat analysis the evaluation the heat pump concepts was possible. The COP1 for the CHP resulted at 3,8 and the COP1 for the GHP was assumed to be the same as for the CHP. The COP1 calculations for the BHP concept resulted at 2,5. COP was calculated with collected data from the respective ice rinks refrigeration system. The simulations results were that the BHP and the CHP concept could fulfill the heat demand up to around 79% and the GHP up to around 84% in both ice rinks. The rest of the heat demand is heated with supplementary heat. The life cycle cost (LCC) showed that the CHP concept had the lowest cost followed by the GHP concept. The BHP concept had the highest LCC, because of the low COP. The LCC model dos not include the running cost, the maintenance cost and the energy tariffs for the district heating.The recommended solution is the GHP concept. This is because it is a good investment for the future since other buildings can be connected to the energy storage. The GHP concept is also the solution that fulfills the heat demand best and has the lowest annual energy cost.
34
Rink, Michael Verfasser], Martin [Akademischer Betreuer] Dietzfelbinger, Konstantinos [Akademischer Betreuer] [Panagiotou, and Rasmus [Akademischer Betreuer] Pagh. "Thresholds for Matchings in Random Bipartite Graphs with Applications to Hashing-Based Data Structures / Michael Rink. Gutachter: Konstantinos Panagiotou ; Rasmus Pagh. Betreuer: Martin Dietzfelbinger." Ilmenau : Universitätsbibliothek Ilmenau, 2015. http://d-nb.info/1074139356/34.
Full text
35
Rink, Michael Verfasser], Martin [Akademischer Betreuer] [Dietzfelbinger, Konstantinos [Akademischer Betreuer] Panagiotou, and Rasmus [Akademischer Betreuer] Pagh. "Thresholds for Matchings in Random Bipartite Graphs with Applications to Hashing-Based Data Structures / Michael Rink. Gutachter: Konstantinos Panagiotou ; Rasmus Pagh. Betreuer: Martin Dietzfelbinger." Ilmenau : Universitätsbibliothek Ilmenau, 2015. http://nbn-resolving.de/urn:nbn:de:gbv:ilm1-2014000557.
Full text
36
Khalid, Waqas. "Energy Usage prediction model comparing Indoor Vs. Outdoor Ice Rinks." Thesis, KTH, Tillämpad termodynamik och kylteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-91164.
Full textAbstract:
Indoor ice rinks use 1091 MWh per annum for ice hockey based on statistics from over 100 Swedish ice rinks (Stoppsladd, 2011).The refrigeration system contributes 35 to75%( (Rogstam, 2010) of total energy usage in ice rinks with average value of 43% (Stoppsladd, 2010) for indoor to 75% for outdoor ice rinks. The basic aim of project is to reduce energy consumption in Swedish ice rinks and scope is for indoor and outdoor ice rinks in cold and mild summer climatic conditions like Sweden. To achieve target of energy reduction in ice rinks actual heat loads on outdoor bandy ice rink are being estimated along with performance analysis of refrigeration machine. The refrigeration system, heat loads on ice surface and their correlation is studied and analyzed in detail for Norrtälje Outdoor bandy ice rink for four warm days and whole season 2010-2011. The tricky and significant task of validation of input climate data for accurate heat loads calculations is completed with Swedish Metrological & Hydrological (SMHI) climate model data, correlations and related web based geographical data. The heat loads (conductive, convective and radiant) on outdoor bandy ice rink are calculated through thermodynamic relations with validated input climate data and measurements where as refrigeration system performance is monitored and analyzed with ClimaCheck(CC) instrumentation. The average cooling capacity is calculated for four warm days by CC internal method and actual cooling energy produced is obtained by practically assumed COP of system with aid of MYCOM compressor software. The cooling capacity and heat loads on ice surface are compared and analyzed considering energy usage affecting parameters and weather parameters like temperature, wind speed, relative humidity and solar load. The convection and condensation are contributing 75%, radiation 18%, ice resurfacing 4% and ground and header heat gain 3% to total heat loads on ice sheet for whole season. The deviation between total cooling energy produced by refrigeration machine and total heat load energy is found 19% and 27% for four warm days and whole season 2010-2011.The deviation is due to overestimation of heat losses from compressor’s body, compressor’s on and off operations, overestimated radiation heat load due to unmeasured negative radiation and lack of actual ice resurfacing heat load evaluation. The developed model in MS Excel allows comparison of field climate data with SMHI model data, indoor and outdoor ice rinks in terms of predicted energy usage by refrigeration system and in total and acts as decision tool to choose for building an indoor/outdoor ice rink.
37
Pospíšilová, Lenka. "Konstrukce zastřešení kluziště." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227469.
Full textAbstract:
This document describes the design of the roof structure for the dimensions of the rink. It was designed and evaluated three roofing solutions – steel truss structure, concrete arch with external prestress and prestress truss roof girder with concrete roof panel. One option was selected – prestress truss girder. This variant has been further developed. In the beginning was drafted several proposals geometry respecting the demands on the type of construction. Within the static calculation was created a mathematical model of the structure of the program Scia Engineer. Using this model were obtained values needed for the assessment of individual elements of construction and design assessment as a whole for the ultimate limit state and usability. According to the proposed geometry and opinions parts of the structure was drawing documentation structure as a whole and individual parts of the structure solved in this thesis. The last proposal was visualized structures together with the phases of the construction by program ArchiCAD and rendered by program Artlantis.
38
Araujo, Rosa Thiago Ferreira de Verfasser], Gabriele [Akademischer Betreuer] [Pradel, and Lothar [Akademischer Betreuer] Rink. "The molecular mechanisms of complement evasion by asexual blood stages and infective sporozoites of Plasmodium falciparum / Thiago Ferreira de Araujo Rosa ; Gabriele Pradel, Lothar Rink." Aachen : Universitätsbibliothek der RWTH Aachen, 2018. http://d-nb.info/1180731239/34.
Full text
39
Dellenbaugh, Mary Hartshorn [Verfasser], Dagmar [Akademischer Betreuer] Haase, Dieter [Akademischer Betreuer] Rink, and Andrej [Akademischer Betreuer] Holm. "Landscape changes in East Berlin after 1989 : a comprehensive grounded theory analysis through three case studies / Mary Hartshorn Dellenbaugh. Gutachter: Dagmar Haase ; Dieter Rink ; Andrej Holm." Berlin : Humboldt Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2014. http://d-nb.info/1053704046/34.
Full text
40
Pierri, Jacqueline. "ManagementPractical Aspects of Aqua Ammonia as Secondary Refrigerant in Ice Rinks." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-289392.
Full textAbstract:
The transition from fluorinated gases to natural refrigerants could be key to reducing the impacts of climate change. Ice rinks are energy-intensive buildings, with large heating and cooling demands. The pumping power required to move the secondary refrigerant typically accounts for a sizable amount of the energy use of the refrigeration system. The use of aqua ammonia as a secondary fluid shows promising results, with pumping power use of about half that required of ethylene glycol, environmental friendliness, and low corrosivity to steel components. Aquaammonia is still novel but is currently in usein 34 Swedish ice rinks. This thesis addresses questions regarding evaporation rates, performance, material compatibility, safety, and regulations of aqua ammonia in ice rink systems. Laboratory tests were performed to assess aqua ammonia evaporation rates during storage and operations. Long-duration concentration change, in well-sealed and well-stored containers, indicated low levels of evaporation for all tested concentrations samples. Short-term concentration in open-air conditions, indicated rapid rates of evaporation, with nearly full evaporation of all ammonia concentration occurring within only 90seconds of open-air exposure. Testing of sample-mixtures containing contamination by substances aquaammonia was likely to encounter during retrofit replacement situations determined that aquaammonia and calcium chloride produce flakey sedimentation. Additionally, lower concentrations of aquaammonia are slightly more prone to becoming basic when mixed with the tested substances, such as calcium chloride. Historical data of systems operating with aquaammonia were analyzed for energy performance. While pumping requirements typically account for 10-20% of the energy for refrigeration, the pumps of the rinks studied with aqua ammonia accounted for only 1.2 to 4.2%. However, data availability and system configuration anomalies suggest additional analyses are required. Furthermore, best operating, maintenance, and safety practices were analyzed and global regulatory restrictions were examined. Surveying of manufacturer material compatibility information found copper and brass to be incompatible with aqua ammonia, while steel and carbon steel are recommended. Various plastics were addressed by the manufacturers, notably PVC was found to be acceptable for use with aqua ammonia. A cost comparison between aqua ammonia and calcium chloride found aqua ammonia to require less expensive equipment. Finally, aqua ammoniawas determined to fall outside of the classification of refrigerants in several international refrigeration codes. Various additional safety regulations guiding personal protective equipment, exposure times, transportation, storage, and disposal regulations were catalogued as part of this work. In summary, aqua ammoniawas found to be a safe substance with performance that matches theoretical energy savings. Pumping requirements were reduced from 10-20% to approximately 1-5% of overall refrigeration system energy use. Necessary safety precautions were found to be much less stringent than high concentrations of ammonia and aqua ammonia was ascertained to fall outside of refrigeration codes in Europe, Canada, and the United States of America.Övergången från fluorerade gaser till naturliga köldmedier kan vara nyckeln till att minska effekterna av klimatförändringen. Isbanor är energikrävande byggnader med stora värme-och kylbehov. Den pumpeffekt som krävs för att pumpa köldbärare står vanligtvis för en stor mängd energianvändning i kylsystemet. Användningen av ammoniakvatten som köldbärare visar lovande resultat, med användning av pumpeffekt på ungefär hälften som krävs av etylenglykol, miljövänlighet och låg korrosion för stålkomponenter. Ammoniakvattenär fortfarande ny men används för närvarande i 34 svenska isbanor. Detta exjobb behandlar frågor om avdunstningshastigheter, energiprestanda, materialkompatibilitet, säkerhet och föreskrifter för ammoniakvatten i isbanasystem. Laboratorietester utfördes för att bedöma avdunstningshastigheter för ammoniakvatten under lagring och drift. Långvarig koncentrationsförändring, i väl tillslutna och välförvarade behållare, indikerade låga nivåer av avdunstning för alla testade koncentrationsprover. En kortvarig koncentration under friluftsförhållanden indikerade snabba avdunstningshastigheter, med nästan full avdunstning av all ammoniakkoncentration inom endast 90 sekunder efter exponering. Testning av olika ammoniakvatten lösningar som innehåller föroreningar skulle sannolikt påträffas vid byte av köldbärare. Dessutom är lägre koncentrationer av ammoniakvatten lite mer benägna att bli basiska när de blandas med de testade ämnena. Historiska data för system som arbetar med ammoniakvatten analyserades med avseende på energiprestanda. Medan pumpeffekten vanligtvis står för 10-20% av kylenergin, pumparna för de studerade isbanorna med ammoniakvatten behövde bara för 1,2 till 4,2%av kylenergi. Datatillgänglighet och systemkonfigurationsavvikelser föreslår dock att ytterligare analyser krävs. Dessutom analyserades bästa metoder för drift, underhållning och säkerhet och globala regleringsbegränsningar. Kartläggning av tillverkarens materialkompatibilitetsinformation visade att koppar och mässing var oförenliga med ammoniakvatten, medan stål och kolstål rekommenderas. Olika plast och packning materialbehandlades, särskilt PVC var acceptabelt för användning med ammoniakvatten. En kostnadsjämförelse mellan ammoniakvatten och kalciumklorid köldbärare visade att ammoniakvatten krävde billigare utrustning. Slutligen visades det att ammoniakvatten faller utanför klassificeringen av köldmedier i flera internationella kylnormer. Olika ytterligare säkerhetsreglersom styr personlig skyddsutrustning, exponeringstider, transport, lagring och bortskaffande föreskrifter katalogiserades som en del av detta arbete. Sammanfattningsvis visade ammoniakvatten vara ett säkert ämne med prestanda som matchar teoretiska energibesparingar. Pumpeffekten minskade mellan 10-20% och 1-5% av den totala energianvändningen i kylsystemet. Nödvändiga säkerhetsåtgärder visade sig vara mycket mindre stränga än att höga koncentrationer av ammoniak och ammoniakvatten konstaterades falla utanför kylnormeri Europa, Kanada och USA.
41
Singer, Cornelia [Verfasser], Johannes [Gutachter] Haerting, Christoph [Gutachter] Rink, Jonas Michael [Gutachter] Rosendahl, and Ingolf [Gutachter] Schiefke. "Kolorektale Neoplasien im Landkreis Aue-Schwarzenberg Analyse der Koloskopien am HELIOS Klinikum Aue im Zehnjahreszeitraum 1996 - 2005 / Cornelia Singer ; Gutachter: Johannes Haerting, Christoph Rink, Jonas Michael Rosendahl, Ingolf Schiefke." Halle (Saale) : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2019. http://d-nb.info/1210729687/34.
Full text
42
Singer, Cornelia [Verfasser], Johannes Gutachter] Haerting, Christoph [Gutachter] [Rink, Jonas Michael [Gutachter] Rosendahl, and Ingolf [Gutachter] Schiefke. "Kolorektale Neoplasien im Landkreis Aue-Schwarzenberg Analyse der Koloskopien am HELIOS Klinikum Aue im Zehnjahreszeitraum 1996 - 2005 / Cornelia Singer ; Gutachter: Johannes Haerting, Christoph Rink, Jonas Michael Rosendahl, Ingolf Schiefke." Halle (Saale) : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2019. http://d-nb.info/1210729687/34.
Full text
43
Deelstra, Oetze Theodoor. "Stora författare från periferin : En jämförande studie mellan minoritetslitteratur från Friesland och Svenskfinland, med romanerna de fûke (1966) och Där vi en gång gått (2006) som utgångspunkt." Thesis, Uppsala universitet, Litteraturvetenskapliga institutionen, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-296226.
Full textAbstract:
This master’s thesis considers the differences between the minority literature from Friesland, a province in the northwest of the Netherlands, and that of the Swedish-speaking part of Finland. The author of this paper tries to draw attention to the literatures of those minorities, which often are not well-known outside their own regions. The main issue discussed in this paper is: How is minority culture problematized in the novels de fûke (1966) by the Frisian author Rink van der Velde and Där vi en gång gått (2006) by the Finland-Swedish author Kjell Westö? The Frisian population in the Netherlands is considered by many as a very old people, because famous writers of the Roman Empire, such as Pliny the Elder, wrote specifically about their region and its people. Despite this, the Frisian language has been in a peripheral situation for many centuries. The Swedish minority in Finland, on the contrary, is much younger. Finland gained autonomy in 1809 and before that time the region currently known as Finland, was the eastern part of the Kingdom of Sweden. This meant that Swedish was the predominant language until that year. Later on Finnish became the main language in Finland. However, both the Frisian and the Finland-Swedish literature were not established before the nineteenth century. This changed partially as a result of ideas of the Romanticism, but also because of historical reasons. By analyzing the previously mentioned novels, Oetze Deelstra shows how the minorities in both countries fare in opposite situations. The Swedish-speaking population has often been, and continues to be, examined as upper-class. On the other hand, in Frisia should a very old countryside culture has been preserved. Those ideas have been important in forming the images of both minorities. A noticeable distinction is that the Frisian literature is defined by language, while the Finland-Swedish literature is characterized by political and ideological arguments.Dizze masterskripsje rjochtet him op de ferskillen tusken de literatuer fan Fryslân en dy fan de Sweedsktalige minderheid yn Finlân. De skriuwer fan dit wurk besiket op dy wize mear omtinken te freegjen foar de literatuer fan dizze minderheden, dy’t faak net sa bekend is bûten de eigen regio. De fraach dy’t sintraal stiet is: Op hokker wize wurdt stal jûn oan minderhedeproblematyk yn de romans de fûke (1966) fan de Fryske skriuwer Rink van der Velde en Där vi en gång gått (2006) fan de Finlânsweedske skriuwer Kjell Westö? Faak wurde de Friezen beskôge as in âld folk. Mooglik komt dat trochdat se al neamd wurde soene troch ferneamde skriuwers fan it Romeinske Ryk, lyk as Plinius de Aldere. Dochs hat it Frysk iuwenlang in net al te wichtige rol spile yn Fryslân en dêrbûten. De Sweedske minderheid yn Finlân is lykwols folle jonger. Finlân is pas sûnt 1809 autonoom en foar dy tiid wie dat wat wy hjoed-de-dei Finlân neame, it eastlike diel fan it Sweedske Ryk. Dat betsjut ek dat it Sweedsk oant doe ta de oerhearskjende taal wie. Letter waard it Finsk de wichtichste taal yn Finlân. Sawol de Fryske as de Finlânsweedske literatuer wiene lykwols net fêstige foar de njoggentjinde iuw. Dat feroaret pas yn de Romantyk, foar in diel fanwege de idealen út dy tiid, mar ek om politike redenen. Troch de earderneamde romans te analysearjen, lit Oetze Deelstra sjen hoe’t de minderheden fan beide lannen eins yn tsjinstelde situaasjes operearje. De Sweedsktalige befolking fan Finlân is faak, en wurdt no noch hieltyd, besjoen as de boppeklasse. Yn Fryslân soe oan ’e oare kant in iuwenâlde lanboutradysje bewarre bleaun wêze. Dizze opfettings hawwe wichtich west foar de byldfoarming fan beide minderheden. In opfallend ferskil is dat de Fryske literatuer fan de eigen taal út definiearre wurdt, wylst de Finlânsweedske literatuer karakterisearre wurdt troch politike en ideologyske útgongspunten.
44
Lind, Philip. "A study of modelling the energy system of an ice rink sports facility : Modelling the heating and cooling of ABB arena syd and implementation of renewable energy sources using TRNSYS." Thesis, Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-40054.
Full textAbstract:
Environmental issues are important challenges for today’s society. Lots of the energy used by humans comes from fossil energy sources resulting in the environmental threats. A considerable amount of this energy is used in the building sector. Industrial buildings and sports facilities are large users of energy and thus becomes very interesting in an optimization point of view. Modelling of the systems allows for cheap and effective optimizing of the energy usage and effectivity measures can be investigated and implemented. This study creates a model of the indoor ice rink arena of ABB arena syd in Västerås using TRNSYS as the main software for simulation. Focus is placed on the heating of the arena through heat pumps and district heating, and cooling of the ice in the arena using cooling machines. The effect of PV as well as a battery storage in the arena is also investigated as an effectiveness scenario. The results from the study revealed that it is possible to simulate the heating demand for the arena, accurately identifying the normal demand as well as the instances when the demand peaks and the magnitude of the peaks. It is also possible to simulate the cooling demand for the ice over extended time periods. However, this study could not identify the peaks for cooling demand. It is also beneficial for the system to install PV, but not a battery storage. With current price levels for electricity it is however not a very beneficial deal. With higher electricity prices the investment is preferable. The study also concludes that TRNSYS can be used for modelling an ice rink sports arena, however it leaves room for improvement on that aspect.
45
Aleknavičius, Marius. "Modeling the evolution of agricultural land markets." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2007. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2007~D_20071204_101606-14316.
Full textAbstract:
This is a summary of doctoral dissertation. Dissertation represents analysis of agricultural land markets development. The analysis was performed by proposing a complex analytical model system and applying it for the investigation of land market development and evolution in Lithuania.Tai yra daktaro disertacijos santrauka. Disertacijoje pateikiama žemės ūkio paskirties žemės rinkų raidos analizė, pagal apžvelgtą teorinę medžiagą pasiūlant kompleksinę tyrimų schemą ir pritaikant ją Lietuvos žemės rinkos kūrimuisi ir vystymuisi tirti.
46
Waldenfjord, Rebecca, Linnea Abrahamsson, and Karolina Engström. "Sharing Surplus Energy at Gränby Sports Field : A case study investigating the possibilities for sharing thermal surplus energy from the ice rinks at the sports field." Thesis, Uppsala universitet, Institutionen för samhällsbyggnad och industriell teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-444198.
Full textAbstract:
This project aimed to investigate the existence of thermal surplus energy from the ice rinks at Gränby Sports Field, Uppsala. Furthermore, a secondary goal was to suggest a distribution system for sharing the potential surplus energy. To fulfil the purpose, each ice rink was modelled in the software IDA ICE. The following ice rinks were considered: buildings A and B, building C and the bandy arena. Data regarding the total heat and cold consumption for each building was collected from the owner, Uppsala kommun Sport- och rekreationsfastigheter AB, and was used to validate the simulation results from the building models. The results from IDA ICE were presented in graphs that illustrate each ice rink’s total heat and cold consumption, surplus energy and energy balance. However, the results from the models in IDA ICE were not validated within a deviation of a maximum of 10% when compared to the data from Uppsala kommun Sport- och rekreationsfastigheter AB. Hence, the results were analyzed on a general level, which showed that there was a greater need for heating during wintertime, with certain peaks during the coldest months, whereas the cooling is maintained at a relatively stable level throughout the year, but with a slightly greater need in the summer. Further on, there was an identified surplus energy from the ice rinks, in terms of waste heat from the refrigeration systems. During the summer there was a greater amount of surplus heat generated, caused by the greater cooling demand. Due to not being able to validate the models, complementary calculations of the yearly surplus heat were made with data from Uppsala kommun Sport- och rekreationsfastigheter AB. The surplus heat was 1 200 MWh for buildings A and B, 497 MWh for building C and 1 492 MWh for the bandy arena. No surplus cold was identified within the ice rinks. The suggested solution for sharing the surplus energy is to implement seasonal thermal storage, due to the similar characteristics in heating and cooling demand for the ice rinks. The stored surplus energy could cover the ice rink’s peaks in heating demand during winter, which is an energy-efficient way would reduce purchased heat from the district heating grid. For further studies, it is of great interest to identify the possibilities of implementing a distribution system similar to the fifth generation district heating as well as seasonal storage, to possibly enable a direct share of energy between all the buildings within the sports field.
47
Rink, Ann-Kathrin [Verfasser]. "Mass and life-time measurement of the 1.7ms 215-Po isotope : a crucial test of the novel concept of the cryogenic ion catcher for the Super-FRS at GSI-FAIR / Ann-Kathrin Rink." Gießen : Universitätsbibliothek, 2017. http://d-nb.info/1139638823/34.
Full text
48
Lindqvist, Simon. "Styrning av en roterande sorptionsavfuktare i en oventilerad ishall." Thesis, Högskolan i Gävle, Energisystem och byggnadsteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-32844.
Full textAbstract:
Kondensbildning är ett stort problem i ishallar vilket leder till stora konsekvenser ifall det inte åtgärdas. Installation av ett avfuktningssystem är ett måste i ishallar men det betyder högre energianvändning. Denna studie undersöker hur RH-styrning (relativ fukthalt) för en avfuktare i PF Arenan lokaliserat i byn Lindefallet i Hudiksvalls kommun kan energieffektiviseras och samtidigt se till att kondensbildning undviks i ishallen. Kondensbildning i ishallar framkommer framförallt på takytan och isplanen. Kondens på isplanen sker när luftens absoluta luftfuktighet är större än den absoluta fuktigheten för isens gränsskikt. Eftersom isen har en temperatur under 0 °C så kommer vattnet att frysas på planen vilket åtgärdas genom att slipa isen med en ismaskin. Forskning visar att avfuktningsstyrning för att undvika kondens på isplanen leder till att avfuktaren blir överdimensionerad för att undvika takkondens. Konsekvenser för takkondens anses som mer allvarliga än de för kondens på isplanen, vilket har lett till att framtagning av ny styrning har fokuserat på att undvika takkondens. Mätningar har utförts i PF Arenans roterande sorptionsavfuktare och lufttillstånden inuti ishallen samt utomhus. Resultatet från mätningar används för att avgöra om det sker kondensbildning i ishallen. Olika styrstrategier jämförs med befintlig RH‑styrning för att fastställa vilka förbättringar som kan tillämpas. Resultat visar att vid stora personlaster och användning av ismaskinen leder till att takkondens framkommer under korta perioder. Samtidigt så går inte regenereringsbatteriet på maxeffekt under dessa perioder vilket betyder att avfuktningskapaciteten kan höjas. RH-styrning leder till överdimensionering i förhållande till båda kondensfenomenen under stora perioder, speciellt under kalla inomhustemperaturer. Föreslagen styrning går ut på att processluftens daggpunkt ska hållas två grader Celsius under takets yttemperatur. Styrningen kan definieras som en varierande daggpunktsstyrning. Det rekommenderas också att regenereringstemperaturen ökar ju mer börvärdet avviker från målfunktionen. Dock så analyserades inte en sådan ökning av regenereringstemperaturen i detalj. Det approximerades att ungefär 1 100 kWh el per månad kan sparas för avfuktaren motsvarande en energiminskning av 22 % gentemot den befintliga styrningen. Approximering förmodar att ismaskin slipar isen lika mycket med båda styrningarna och tar inte hänsyn till den ökade energianvändningen ifall högre regenereringstemperaturer tillämpas i avfuktaren.Condensation is a major problem in ice rink arenas and if it is not resolved, will lead to construction damages. Generally, ice arenas use dehumidifiers to dehumidify the indoor air which causes an increase in energy use in the facility. This study investigates how the control strategy of the dehumidifier in the PF Arena localized in Lindefallet in Hudiksvall municipality can be improved to save energy while preventing the occurrence of condensation in the ice rink arena. Condensation in ice arenas occur on the ice surface and roof surface. Ice surface condensation occur if the indoor air humidity is higher than the humidity of the ice surface boundary layer. The ice will freeze the moisture onto the surface which require an ice resurfacer to flatten the playing field. Studies has shown that control strategies for dehumidification to prevent condensation on the ice surface results in oversizing of the dehumidifier for preventing condensation on the roof surface. And as condensation on roof surface leads to more serious consequences than that of ice surface condensation, it is of more interest to prevent the former. Measurements has been carried out on PF Arenan’s desiccant wheel dehumidifier and indoor as well as outdoor air. Results from measurements are used to analyze if any condensation occurs in the ice rink arena. Other control strategies are compared to the one used in PF Arenan to determine what improvements can be applied to the dehumidifier. Results show that during events and use of ice resurfacers some condensation on the roof surface occurs for short periods. During these periods, the regeneration heater does not use full power which could be used to increase the moisture removal capacity. The RH-control strategy results in oversizing for most hours when controlled to both condensation phenomenon, especially during cold temperatures. The recommended control strategy is to keep the dewpoint of the inlet process air 2 °C below the roof surface temperature. This control strategy is a type of variable dewpoint control function. It is also recommended to increase the regeneration temperature proportionally to the difference between the setpoint and the objective function. However, the results of this measure were not analyzed in detail. The new control strategy would approximately save 1 100 kWh per month over the current control function which amounts to an energy use decrease of 22 % for the dehumidifier. Assumed that behavior of ice resurfacing is not changed with the new control function and the approximation does not consider the increase of energy use if the regeneration temperature is increased.
49
FEHLING, SIMON. "CO2 Refrigeration withIntegrated Ejectors : Modelling and Field Data Analysis ofTwo Ice Rinks and Two Supermarket Systems." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-299502.
Full textAbstract:
With the increasing importance of CO2 as natural refrigerant with low Global Warming Potential(GWP) ejectors have been used in a number of recent installations to recover expansion work atthe high operating pressures of these systems. In colder climates, this is particularly seen in combinationwith heat recovery due to the high compressor discharge pressures.This work analyses the field measurement data of two ice rink refrigeration systems with integratedvapor ejectors and two supermarket refrigeration systems with integrated liquid ejectors, alllocated in northern Europe. The aim is to evaluate the interaction of the ejector with the refrigerationsystem in practical applications. A theoretical model of the ejector systems is developed andevaluated in parallel as a reference for the analysed system installations.The model of the analysed vapor ejector system shows an increasing eciency improvement potentialby the ejector for higher gas cooler outlet temperatures, while the liquid ejector systemmodel indicates higher eciency improvement potential at relatively lower gas cooler outlet temperaturesand pressures.From the vapor ejector field data evaluation, this is confirmed with additional findings of lowejector work recovery eciencies at low gas cooler outlet temperatures. Furthermore, problemsin the ejector operation are found for too low evaporation temperatures in one of the systems. Inaddition, an unstable ejector control at certain operating conditions is linked to a decreasing ejectorperformance. While the ejector is found not to provide any significant savings in one of the systemsmainly due to low evaporation temperatures, the other ice rink system is found to achievetotal energy savings of 7% from the ejector.For the liquid ejector field data evaluation, the ejectors are found to work as expected for the purposeof removing liquid from the low-pressure receiver. However, overfed evaporation conditionsare only found temporarily for most cabinets in the analysed systems, with remaining high averagesuperheat values. Low required air supply temperatures in the cabinets and the dimensioning of theexpansion valves at the evaporator inlet are identified as possible limitations for a further decreaseof the superheat and increase of the evaporation temperature.Med den ökande betydelsen av CO2 som naturligt köldmedium med låg global uppvärmningspotential(GWP) har ejektorer använts i ett antal nya installationer för att återvinna expansionsarbetevid de höga drifttrycken i dessa system. I kallare klimat är detta särskilt vanligt i kombination medvärmeåtervinning på grund av de höga utloppstrycken i kompressorerna.I detta arbete analyseras fältmätdata från två kylsystem för isbanor med integrerade ångejektoreroch två kylsystem för livsmedelsbutiker med integrerade vätskeejektorer. Samtliga system finns inorra Europa. Syftet med studien är att utvärdera ejektorns samverkan med kylsystemet i praktiskatillämpningar. En teoretisk modell av ejektorsystemen utvecklas och utvärderas parallellt som referensför de analyserade systeminstallationerna.Modellen för det analyserade ångejektorsystemet visar att potentialen för e ektivitetsförbättringgenom ejektorn ökar vid högre utloppstemperaturer för gaskylare, medan modellen försystemet med vätskeutkastare visar att potentialen för e ektivitetsförbättring ökar vid relativt lägreutloppstemperaturer och tryck för gaskylare.Detta bekräftas i utvärderingen av fältdata från ångejektorsystemen som vid låga utloppstemperatureri gaskylaren samtidigt ger låg e ektivitet för ejektorn. Dessutom noteras problemmed ejektorns funktion vid för låga förångningstemperaturer i ett av systemen. En instabilstyrning av ejektorn vid vissa driftsförhållanden leder vidare till en minskad ejektore ektivitet.Medan ejektorn inte ger några betydande besparingar i det ena systemet, främst på grund av lågaavdunstningstemperaturer, har en total energibesparing på 7% från ejektorn hittats i den andra isbanan.När det gäller utvärderingen av fältdata för vätskeejektorer konstateras att ejektorerna fungerar somförväntat för att avlägsna vätska från vätskeavskiljaren. För de flesta kyldiskar i de analyseradesystemen syns dock bara kortvarigt flödad tillstånd i förångrarna, och i övrigt en kvarvarande höggenomsnittlig överhettning. Låg erforderlig tilluftstemperatur i kyldiskarna och dimensioneringenav expansionsventilerna vid förångarens inlopp identifieras som möjliga begränsningar för enytterligare minskning av överhettningen och en ökning av förångningstemperaturen.
50
Doležal, Jan. "Průmyslové chladicí systémy." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265270.
Full textAbstract:
This thesis describes the design of cooling ice rink. Cooling system design is based on a physical nature, measured data and observations from practice. The result is a proposal cooling system with the highest possible cooling factor, which uses waste heat for technology needs snow pit and hot water, in order to achieve the lowest cost of operation ice rink.