Artículos de revistas: "Refrigeration and refrigerating machinery Refrigeration and refrigerating machinery Refrigeration and refrigerating machinery"

1

Lebedev, B., L. Knaub, E. Lebedeva y E. Pavlishko. "AN EXPERIMENTAL STUDY OF THE AMMONIA HERMETIC SMALL REFRIGERATION MACHINE." Аграрний вісник Причорномор'я, n.º 94 (25 de diciembre de 2019): 139–54. http://dx.doi.org/10.37000/abbsl.2019.94.20.

Texto completo

Resumen

The article focuses on the study of the design parameters of small refrigerating machines. This article shows practical studies of the dependence of the energy parameters of the refrigerating machine on its design features.In particular, the dependence of the coefficient of performance upon the superheating of steam at the suction in the compressor was studied, and preventing method of such overheating for small refrigerating machines was proposed. At the second stage the possibility of using a regenerative heat exchanger in an ammonia refrigerating machine was examined. The advantages of its use are shown. In general, the possibility of increasing the refrigeration efficiency by changing design parameters of the refrigerating machine is shown.

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Petushenko, S. "Cooling System for Primary Low Temperature Processing and Storage of Grains of Small Frachioned". Refrigeration Engineering and Technology 53, n.º 5 (2 de noviembre de 2017): 52–58. http://dx.doi.org/10.15673/ret.v53i5.852.

Texto completo

Resumen

The analysis of different aspects of grain refrigeration on elevators of Ukraine, Commonwealth of Independent States (CIS) and in the world is carried out. The advantage of the refrigeration method is shown concerning the quality and of energy conservation. A comparative analysis of various types of refrigeration machines operating on ozone-friendly refrigerants has been carried out. It is shown that it is more profitable to use heat that is worked out from refrigerating machines.

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

Kirillov, N. G. "Stirling Refrigerating Machines — Promising Equipement for Moderate Refrigeration". Chemical and Petroleum Engineering 41, n.º 7-8 (julio de 2005): 372–76. http://dx.doi.org/10.1007/s10556-005-0123-5.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Dobre, Cătălina, Lavinia Grosu, Alexandru Dobrovicescu, Georgiana Chişiu y Mihaela Constantin. "Stirling Refrigerating Machine Modeling Using Schmidt and Finite Physical Dimensions Thermodynamic Models: A Comparison with Experiments". Entropy 23, n.º 3 (19 de marzo de 2021): 368. http://dx.doi.org/10.3390/e23030368.

Texto completo

Resumen

The purpose of the study is to show that two simple models that take into account only the irreversibility due to temperature difference in the heat exchangers and imperfect regeneration are able to indicate refrigerating machine behavior. In the present paper, the finite physical dimensions thermodynamics (FPDT) method and 0-D modeling using the Schmidt model with imperfect regeneration were applied in the study of a β type Stirling refrigeration machine.The 0-D modeling is improved by including the irreversibility caused by imperfect regeneration and the finite temperature difference between the gas and the heat exchangers wall. A flowchart of the Stirling refrigerator exergy balance is presented to show the internal and external irreversibilities. It is found that the irreversibility at the regenerator level is more important than that at the heat exchangers level. The energies exchanged by the working gas are expressed according to the practical parameters, necessary for the engineer during the entire project. The results of the two thermodynamic models are presented in comparison with the experimental results, which leads to validation of the proposed FPDT model for the functional and constructive parameters of the studied refrigerating machine.

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

Bukin, Vladimir Grigorievich, Alexey Vasilievich Ezhov y Aleksander Ivanovich Andreev. "Temperature-entropy diagrams for calculating cycles of refrigerating machines using refrigerant mixtures". Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies 2020, n.º 4 (18 de noviembre de 2020): 79–86. http://dx.doi.org/10.24143/2073-1574-2020-4-79-86.

Texto completo

Resumen

The article represents the advantages and disadvantages of refrigeration machines operating on non-azeotropic refrigerant mixtures. There has been illustrated their specific feature in comparison with pure substances: they are non-isothermal during phase transitions. It can be effective when cooling or heating flows that significantly change the temperature, and ineffective when working with volumes, where it is necessary to maintain a constant temperature. In the first case there takes place a decrease in the internal irreversibility of heat transfer processes in evaporators and condensers; in the second case - an increase. When using mixed refrigerants, it is possible to simultaneously obtain several temperature levels in a single-stage machine at the same pressure in the evaporators, they can obtain low boiling points of the refrigerant without vacuum in the evaporator and regulate the refrigeration capacity of the machine by changing the composition of the mixture. The prospects of using mixtures of working bodies of refrigerating machines have been proved. The diagrams T-S, T-ξ, i-ξ are presented allowing to calculate the cycle of the machine, to determine its operating parameters and to calculate the technical and energy characteristics. The developed thermal diagrams make it possible to accurately examine the dynamics of the boiling and condensation processes of a binary mixture, show the change in the concentration of the mixture in the vapor and liquid phases and make it possible to construct and calculate the cycle of a refrigeration machine operating on a mixed refrigerant. Examples of constructing cycles of two schemes of refrigeration machines operating on a mixed refrigerant are considered: with separation of the working substance flow and without separation. Methods for calculating the cycle are provided

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Zhao, Ya Le, Fang Wang, Jia Wen Zhang, Ding Ding Yang, Tang Li y Yan Liu. "The Simulation Optimization and Experimental Improvement of the Refrigerator". Advanced Materials Research 1051 (octubre de 2014): 840–44. http://dx.doi.org/10.4028/www.scientific.net/amr.1051.840.

Texto completo

Resumen

The Chinese refrigeration industry is faced with dual pressure of energy saving and emission reduction. R600a as an alternative refrigerant of R134a is environment friendly, and the alternation is very good. Firstly, this paper established a two-dimensional steady numerical calculation model of the refrigerating chamber with R600a, and studied the influence of the temperature distribution of the refrigerator’s posterior wall under different schemes on temperature field and velocity field of the refrigerating chamber. When the function of temperature distribution is T=-11.75*y, will achieve the best temperature field and velocity field, and the results are better than the original machine. Secondly, this paper studied the experimental improvement of R600a under the best temperature distribution scheme comparing with R134a.

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

Tyczewski, Przemysław y Wiesław Zwierzycki. "Research Works on the Influence of Substituting the Refrigerant R22 with Propane (R290) on the Condition of the State of Sliding Surfaces Occurring in Piston Compressors". Solid State Phenomena 223 (noviembre de 2014): 163–70. http://dx.doi.org/10.4028/www.scientific.net/ssp.223.163.

Texto completo

Resumen

Motion elements of refrigerating compressors, depending on the applied oils and refrigerants, can be exposed to various wear processes. The presence of refrigerant makes lubricating and anti-wear properties of the mixture of oil and refrigerant much worse than in the case of oil with no refrigerant. Regulations concerning the application of substances weakening the ozone layer, valid at present, demand the withdrawal of operating synthetic agents refrigerating installations type HCFC – among others the popular R22. This paper presents the influence of different mixtures of oils and refrigerants on the moment of friction and the surface condition of cast iron and aluminium PA6. The tests were carried out on a friction machine with the use of a node type block-on-ring, which is located inside a pressure chamber that simulates the refrigeration compressor inside. The results of the performed tests confirm the possibility of using green refrigerant R290 (propane) as a substitute for R22, while keeping the existing mineral oil in the refrigerating installation.

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Busakhin, Alexey. "Principles of selection and optimization of cooling systems in public buildings". E3S Web of Conferences 244 (2021): 09013. http://dx.doi.org/10.1051/e3sconf/202124409013.

Texto completo

Resumen

Aspects of selecting the most effective refrigerating machine for air conditioning systems, taking into account the comparative analysis of the energy efficiency of the refrigerating machine are considered. The purpose of the work is to improve the regulatory framework governing the design, construction and operation of buildings and structures, to obtain sufficient theoretical and reliable calculated data to determine the standardized parameters and clarify the requirements for the design, construction and operation of buildings and structures. The requirements should be focused on ensuring safe for human health conditions of residence and stay in buildings and structures and the energy efficiency of buildings and structures in order to implement the requirements of the Federal Law of December 30, 2009 No. 384-FZ “Technical Regulations on the Safety of Buildings and Structures”. The aim of the study is to ensure the protection of the life and health of citizens, property of individuals and legal entities, state or municipal property, to bring methods for determining operational characteristics and assessment methods to the uniformity, to ensure mutual consistency of existing regulatory technical documents in the construction industry. The object of the study is the refrigeration and air conditioning systems of public buildings.

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Osadchuk, Eugeniy y Oleksandr Titlov. "ANALYSIS OF THE CLIMATIC FEATURES OF THE REGIONS OF THE PRIMARY APPLICATION OF THE SYSTEMS FOR PRODUCING WATER FROM THE ATMOSPHERIC AIR". ScienceRise 4 (31 de agosto de 2020): 3–9. http://dx.doi.org/10.21303/2313-8416.2020.001390.

Texto completo

Resumen

The object of research is the thermal and humidity processes occurring during artificial cooling of atmospheric air to the dew point temperature in the evaporators of refrigeration machines of the compression and absorption type. This study solves the problem of finding energy efficient heat and humidity modes for cooling atmospheric air to the dew point temperature in regions with a shortage of water resources and high solar installations. It is shown that practically in all considered climatic zones with a shortage of water resources, the process of obtaining water from atmospheric air is most energetically expended in the winter period of the year, and the most energetically efficient - in the summer period. In the summer period of the year, the specific energy consumption is numerically comparable in the cooling temperature range from 5 °C to 15 °C. It is also shown that the application of the technology of night radiation will create a reserve of natural cold for additional cooling of condensers of refrigerating machines of various types during the entire period of operation. The area of practical use of the research results: compression and absorption refrigeration machines operating in systems for obtaining water from atmospheric air and taking into account seasonal changes in the thermal and humidity parameters of atmospheric air. An innovative technological product: energy-efficient systems for obtaining water from atmospheric air based on refrigeration machines of the compression and absorption type, which also work with the help of solar radiation. Scope of application of the innovative technological product: systems for supplying the population with drinking and process water, mainly in areas with a shortage of water resources.

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Zhuk, H. V., O. I. Pyatnichko, L. R. Onopa y Yu V. Ivanov. "ENERGY EFFICIENT NATURAL GAS LIQUEFACTION TECHNOLOGIES IN LOW-TONNAGE PLANTS: UKRAINE’S PROSPECTS". Energy Technologies & Resource Saving, n.º 1 (20 de marzo de 2020): 7–18. http://dx.doi.org/10.33070/etars.1.2020.1.

Texto completo

Resumen

Along with the growth of natural gas consumption in the world, small-scale production of liquefied natural gas (LNG) is developing at a faster pace. It opens up the possibility of LNG obtaining and transporting as a commodity product at remote from gas networks fields or wells, and also at low-production wells and alternative sources of methane-containing gas. The development of modern technologies for natural gas liquefaction has been studied and the liquefaction cycles used in the low-tonnage scale have been classified. In Ukraine, rather large reserves of natural gas are found in small as well as depleted fields, so the problem of energy efficient technologies for liquefaction and transportation of their hydrocarbon resources creating is of particular relevance. For the development of such low-resource fields, liquefaction units operating on the compression-throttle cycle are most suitable. Energy efficient technological schemes of natural gas liquefaction plants have been developed: in the high-pressure throttle-ejector cycle with pre-cooling using a propane refrigerating machine and in the middle-pressure throttle cycle with ethane refrigeration cycle and the recovery of part of the liquefied gas. Optimum parameters of the refrigeration cycle and the whole plant are obtained from the point of view of minimizing the specific energy costs. The advantages of the proposed throttle schemes are simplicity, reliability, that are results from the use of standard compressor and refrigeration equipment, and energy efficiency of 0.5 kWh/kg LNG, which is sufficiently high for low-tonnage LNG production. Ref. 20, Fig. 6, Tab.1.

Los estilos APA, Harvard, Vancouver, ISO, etc.

11

Porutchikov, Artem Frolovich y Dmitriy Pavlovich Trubin. "Low temperature vacuum sublimation refrigerators on carbon dioxide as working fluid". MATEC Web of Conferences 324 (2020): 02004. http://dx.doi.org/10.1051/matecconf/202032402004.

Texto completo

Resumen

The paper presents the results of theoretical and experimental analysis of a vacuum-freeze-drying refrigeration machine based on carbon dioxide. Such refrigeration machines can be equipped with refrigerators for the needs of medicine, where low temperatures are widely in demand in the range from minus 80 degrees Celsius to minus 130 degrees Celsius. The problem of developing alternative refrigeration machines is dictated by modern environmental requirements for working substances, which are gradually being tightened and soon the use of familiar freons will become impossible. For the air conditioning and commercial refrigeration industry, new substances are being actively developed, such as hydrofluoroolefins (HFOs), hydrocarbons can also serve as substitutes for hydrofluorocarbons and their mixtures, but it must be considered that they are combustible and explosive. A carbon dioxide vacuum sublimation unit may be an alternative to modern freon vapor compression refrigeration units for the indicated temperature range, but subject to comparable energy costs during its operation. The article examined the three-stage and four-stage cycles of a vacuum-freeze-drying refrigeration machine, conducted their theoretical comparison in terms of COP with a cascade cycle on hydrocarbon working substances. It can be noted that the COP of the considered cycles are close, but the environmental friendliness, safety and non-combustibility of carbon dioxide gives the advantages of a vacuum freeze-drying refrigeration machine.

Los estilos APA, Harvard, Vancouver, ISO, etc.

12

Titlov, Alexandr, Eugeniy Osadchuk, Alexandr Tsoy, Assel Alimkeshova y Rita Jamasheva. "Development of cooling systems on the basis of absorption water-ammonia refrigerating machines of low refrigeration capacity". Eastern-European Journal of Enterprise Technologies 2, n.º 8 (98) (16 de abril de 2019): 57–67. http://dx.doi.org/10.15587/1729-4061.2019.164301.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

13

Lavrenchenko, G. K., J. V. Zmitrochenko, S. M. Nesterenko y M. G. Khmelnuk. "Characteristics of Voorhees refrigerating machine with hermetic piston compressor producing refrigeration at one or two temperature levels". International Journal of Refrigeration 20, n.º 7 (enero de 1997): 517–27. http://dx.doi.org/10.1016/s0140-7007(97)00034-0.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

14

Wall, Göran. "Optimization of refrigeration machinery". International Journal of Refrigeration 14, n.º 6 (noviembre de 1991): 336–40. http://dx.doi.org/10.1016/0140-7007(91)90029-g.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

15

Petrosov, S. P., M. A. Lemeshko, A. V. Kozhemyachenko y S. E. Bashnjak. "Methods of calculation of energy losses of the refrigerator when opening its doors". MATEC Web of Conferences 215 (2018): 01018. http://dx.doi.org/10.1051/matecconf/201821501018.

Texto completo

Resumen

The problem of energy supply and the problem of energy efficiency of energy consumers are global problems. In the modern world, scientists pay much attention to the tasks of creating new and improving traditional sources of electricity. The tasks of increasing the energy efficiency of electricity consumers remain relevant in the global economy. One of the relatively capacious energy consumers is the Park of refrigerators, household and commercial purposes, which are also being improved in order to increase their energy efficiency. Modernization and improvement of household and commercial refrigerators include the task of designing and using more efficient refrigerators. Energy consumption of compression refrigerators, along with other operational factors, depends on the processes of heat exchange and mass transfer of air from internal chambers to the ambient air. When the doors of the refrigerator chambers are opened, the cooled air in the chambers is replaced with the warmer air of the environment. This process causes the cost of operation of the refrigeration machine and characterizes its energy consumption. In order to minimize this power consumption, knowledge of the process of cool air outflow of their open refrigerator chambers is required. Currently, this process is poorly understood. The article presents an approach to the description of the process of motion of the cooled air from the refrigerator chamber, the main assumptions necessary for the construction of a mathematical model of this process are given, and a method for calculating the heat in the refrigerator chambers associated with the replacement of the cooled air with the ambient air inside the chambers is proposed. The method is based on the laws of gas dynamics, supplemented by some experimental studies. In particular, the well — known Navier-Stokes equation is used as the initial basis. This equation supplemented by the continuity equation of the air flow and other functional dependencies. As a result of mathematical transformations and arguments about the physics of the mass transfer process, finite equations are obtained, which allow describing both the performance of the cooled air flow and the amount of heat introduced into the chambers by external warm air. Mathematical dependences are developed for calculation of parameters of motion of a stream of the cooled air and heat inflows, thus the temperature of ambient air and temperature in chambers of the refrigerator are considered. The results of the research will be useful in the design of new refrigerating machines with reduced energy consumption.

Los estilos APA, Harvard, Vancouver, ISO, etc.

16

Радченко, Андрій Миколайович, Дмитро Вікторович Коновалов, Сергій Георгійович Фордуй, Роман Миколайович Радченко, Сергій Анатолійович Кантор y Віктор Павлович Халдобін. "Аналіз ефективності ежекторних холодильних машин на різних холодоагентах". Aerospace technic and technology, n.º 4 (27 de agosto de 2021): 40–47. http://dx.doi.org/10.32620/aktt.2021.4.06.

Texto completo

Resumen

Modern heat-using ejector refrigeration machines used in heat recovery systems for power plants based on gas turbine engines and internal combustion engines have many advantages over absorption refrigeration machines: smaller dimensions and weight; the ability to obtain lower temperatures. However, they are inferior in energy efficiency, and the thermal coefficient is much lower and can be 0.2…0.4. The efficiency of such refrigeration machines largely depends on the choice of the working fluid (refrigerant). Hence the need to choose a refrigerant that would provide the maximum heat factor, and hence the maximum efficiency of heat recovery. Given the relatively low efficiency of the ejector refrigeration machine, the search for a working fluid that will provide, on the one hand, higher thermal coefficients, and on the other hand high environmental friendliness, is one of the promising areas of development of heat recovery technologies in power plants. The study used the software complex developed by the authors to calculate the refrigeration cycles of heat-using refrigeration machines, taking into account the properties of many modern refrigerants, ejector characteristics, as well as basic heat exchangers (condenser, evaporator, generator). The efficiency of ejector refrigeration machines when working on the following working bodies was analyzed: R142b, R134a, R600, R600a, R1234ze(E), R1233zd(E), R1234yf, R227ea, R236fa, R245fa. R142b, R600, R600a, R245fa have the largest values of thermal coefficients. It is established that the most profitable in terms of environmental friendliness (ODP, GWP) and energy efficiency is the use of refrigerant R245fa, which has a condensation temperature range is 25…35 oC and boiling in the evaporator is 0…15 oC thermal coefficient is 0.40…1.03.

Los estilos APA, Harvard, Vancouver, ISO, etc.

17

Belyanovskaya, E. A., G. M. Pustovoy, A. I. Sklyarenko, M. P. Sukhyy, K. M. Sukhyy, О. О. Yeromin y O. M. Prokopenko. "Calculation algorithm for operating parameters of steam-compressive chilling machine with adsorptive chillling unit". Computer Modeling: Analysis, Control, Optimization 8, n.º 2 (diciembre de 2020): 3–9. http://dx.doi.org/10.32434/2521-6406-2020-8-2-3-9.

Texto completo

Resumen

The work is focused on the development of an effective algorithm for calculating the operational characteristics of a steamcompressive chilling machine with an adsorptive chilling unit, which involves a cold box, an adsorber, an evaporator and a condenser, water being used as a refrigerant. An algorithm for calculating the operating parameters of the adsorptive chilling unit has been developed, which includes the determination of the cooling capacity of the steam compressor refrigeration unit, the heat load on the condenser, the power consumed by the compressor, the coefficient of performance of the steam compressor refrigeration unit, as well as the calculation of the mass of water, the mass of the adsorbent, the refrigerating capacity, the coefficient of performance of the adsorptive chilling unit and the coefficient of useful energy utilization of a steam compressive chilling machine with an adsorption chilling unit. The chilling capacity and the coefficient of performance of the adsorption chilling unit are estimated under the operating conditions of a typical steam compression chilling machine. The crucial factors affecting the efficiency of the adsorptive chilling unit are analyzed. It has been established that the chilling capacity, the coefficient of performance of the adsorption refrigeration module and the energy efficiency of the installation are determined by the thermal load on the condenser, and, therefore, by the mass of water that is desorbed and evaporated. The coefficient of performance of the adsorption chilling unit and the efficiency of the steam compressor chilling machine with the adsorptive chilling unit are estimated to be 0.878 and 4.64. The criteria for the selection of adsorbents for the adsorption module are analyzed. The temperature of regeneration is determined by the temperatures in the condenser, and the limit adsorption affects the mass of the adsorbent and the size of the adsorber. A comparison of the efficiency of adsorptive chi l l ing uni t based on silicoaluminophosphates and composite adsorbents «silica gel – sodium acetate» is carried out. The prospects of using composites «silica gel – СН3СООNa» are shown. The optimal composition of the composite was established, which corresponds to the minimal size of the adsorber, (80% sodium acetate and 20% silica gel). The prospects of using adsorptive conversion of thermal energy for utilization of low-potential thermal energy during the operation of steam compressive chilling machine are shown. Keywords: adsorptive conversion of heat energy, composite adsorbent, steam compressive chilling unit, adsorption, adsorptive capacity.

Los estilos APA, Harvard, Vancouver, ISO, etc.

18

Vicatos, George y E. Krafft. "Comparison between two different solution-pumping methods in absorption refrigeration machines". Journal of Energy in Southern Africa 21, n.º 3 (1 de agosto de 2010): 16–22. http://dx.doi.org/10.17159/2413-3051/2010/v21i3a3257.

Texto completo

Resumen

This paper presents a pumping method in absorp-tion refrigeration where a vapour-driven pump is to replace the electricity-driven pump. The vapour pump is driven by a fraction of the generator’s hot, high-pressure, vapour mixture. The refrigerator is thus exclusively heat-powered and rendered inde-pendent of the availability of electricity as the main energy source. The design and operation of the vapour pump is presented. The results obtained by a computer simulation program show a decrease in performance (COP), which is confirmed by the data obtained from a 1 kW cooling capacity refrigerator. Peak performances occur at higher generator tem-peratures when compared to a cycle using an elec-tricity-driven pump

Los estilos APA, Harvard, Vancouver, ISO, etc.

19

Трушляков, Євген Іванович. "МЕТОДОЛОГИЧЕСКИЙ ПОДХОД К ЭНЕРГОСБЕРЕГАЮЩЕМУ ХЛАДОСНАБЖЕНИЮ СИСТЕМ КОНДИЦИОНИРОВАНИЯ ВОЗДУХА АДАПТАЦИЕЙ К ТЕКУЩИМ КЛИМАТИЧЕСКИМ УСЛОВИЯМ". Aerospace technic and technology, n.º 4 (14 de octubre de 2018): 58–62. http://dx.doi.org/10.32620/aktt.2018.4.08.

Texto completo

Resumen

The methodological approach was suggested to define a rational heat load of the air conditioning system (ACS) with taking into consideration the current climatic conditions of operation. The proposed approach is based on the hypothesis of sharing the current changeable heat load on the relatively stable share as the basic one for choosing installed (designed) refrigeration capacity of the refrigeration machine, operating with high energy efficiency in nominal or similar modes, and unstable heat load, corresponding to ambient air precooling at changeable current temperatures. To prove the methodological approach to defining a rational heat load of the ACS was carried out the analysis of current values of heat loads of the refrigeration machine ACS during cooling ambient air from its changeable current temperature to the temperature of 10, 15 and 20 ºС . It is shown that due to the different rates of annular refrigeration capacity production increment to cover the current heat loads with increasing the installed refrigeration capacity of the refrigeration machine, caused by the changes in heat load according to current climatic conditions during all the year round, it is necessary to choose a such heat load on the refrigeration machine of ACS (its installed refrigeration capacity), that provides a maximum or similar annular refrigeration capacity production at relatively high rates of its increment. Therein, the value of heat load for ambient air precooling is calculated according to remained principle as the difference between the rational total heat load and its basic relatively stable share. The proposed method is useful for defining a basic installed refrigeration capacity of the refrigeration machine of ACS with the accumulation of excessive (unapplied) refrigeration capacity at lowered current heat loads on ACS and its application for ambient air precooling, that is for covering unstable heat load share on ACS

Los estilos APA, Harvard, Vancouver, ISO, etc.

20

Tatarenko, J. V., V. M. Mizin y N. O. Rachkovskiy. "PREDICTION OF THE USE OF REFRIGERANTS IN LOW-TEMPERATURE EQUIPMENT". Herald of Dagestan State Technical University. Technical Sciences 46, n.º 3 (24 de noviembre de 2019): 32–42. http://dx.doi.org/10.21822/2073-6185-2019-46-3-32-42.

Texto completo

Resumen

Objectives Determination of prospects for the use of various refrigerants, as well as the potential for their interchangeability in low-temperature equipment in accordance with the conditions of the Kigali Amendment to the Montreal Protocol on substances that deplete the ozone layer.Method A computer simulation of heat exchange processes based on generally accepted dependencies was carried out and data for the construction of refrigeration machine elements obtained.Results R717 and R410A are recommended for use in medium- and low-temperature machines. R32 refrigerant is used in high-temperature refrigeration machines, especially in units with finned copper tubes. The low vapour content of R32 refrigerant prevents steaming of the upper layers of the tube bundle, leading to an increase in the level of the refrigerant in the evaporator and in the working area of the evaporator tube bundle. For R32, it is necessary to conduct additional research to find an alternative refrigerant. The highest values of the heat transfer coefficient are obtained when working on refrigerants R410A and R717.Conclusion The implemented algorithms can be helpful for obtaining the characteristics of the steam-compressor refrigerator elements across a wide range of boiling and condensing temperatures taking various factors and the percentage composition of the mixed working substance into account. This is a highly important consideration when converting the machines to run on alternative refrigerants.

Los estilos APA, Harvard, Vancouver, ISO, etc.

21

Коновалов, Дмитро Вікторович. "АНАЛІЗ ЕФЕКТИВНОСТІ ТЕПЛОВИКОРИСТОВУЮЧОЇ ТЕРМОПРЕСОРНО-ЕЖЕКТОРНОЇ ХОЛОДИЛЬНОЇ МАШИНИ". Aerospace technic and technology, n.º 8 (31 de agosto de 2019): 59–67. http://dx.doi.org/10.32620/aktt.2019.8.09.

Texto completo

Resumen

One of the ways to increase the energy efficiency of ejector refrigerating machines is to use of thermopressor technologies, which are based on to use of the process of thermogasdynamic compression. This process consists in contact cooling and at the same time increasing the gas or steam pressure. The thermopressor application in the ejector refrigerating machines cycle installed at the outlet of the ejector, allows, by increasing the pressure during vapour contact cooling to a saturation tempera-ture, to increase the ejection coefficient U and, accordingly, the thermal coefficient z. A number of refrigerants were chosen for analysis of cycle of ejector refrigerating machines, among which those traditionally is used for ejector refrigerating ma-chines, and a number of other refrigerants that can be used in ejector refrigerating machines based on the possibility of using the thermopressor. It is possible to in-crease the ejector refrigerating machines efficiency by using the thermopressor while ensuring a greater temperature difference. With the temperature difference 60–100 oC, the relative pressure increase is mostly positive. The following refrigerants have the most significance: R717, R134a, R227ea, R1234ze(E), R1234yf. Analysis of the ejector refrigerating machines scheme by using the thermopressor shows that the greatest efficiency at the highest possible boiling points in the generator tg is the refrigerants: R142b, R600, R1233zd(Е), R245fa.

Los estilos APA, Harvard, Vancouver, ISO, etc.

22

Zebbar, Djallel, Souhila Zebbar, Sahraoui Kherris y Kouider Mostefa. "Inert Gas and Refrigerating Vapor Mass Flow Rates Ratio: A Much Promising Parameter for Diffusion-Absorption-Refrigeration Systems Performances Evaluation". Mathematical Modelling of Engineering Problems 8, n.º 2 (28 de abril de 2021): 253–58. http://dx.doi.org/10.18280/mmep.080212.

Texto completo

Resumen

This paper is consecrated to the thermodynamic study and analysis of diffusion-absorption-refrigeration (DAR) plants. The mass and energy balances analysis at the evaporator has allowed to highlight a new and original parameter, which can be used to analyze DAR system performances. It is the ratio of inert gas to refrigerant vapor mass flow rates at the evaporator inlets. This coefficient, which expression has been for the first time deduced mathematically, informs about the quality of the cycle and its performance, which are deeply affected by the growth of the inert gas flow energy expended to drive the refrigerant through the evaporator. The study shows that the coefficient of performance is decreasing with the increase of the mass flow rates ratio. The latter can be also used to find the optimal operating mode for the DAR machine with a specified working fluid.

Los estilos APA, Harvard, Vancouver, ISO, etc.

23

DeBaufre, Wm L. "The Williams Refrigerating Machine". Journal of the American Society for Naval Engineers 31, n.º 2 (18 de marzo de 2009): 454–69. http://dx.doi.org/10.1111/j.1559-3584.1919.tb00794.x.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

24

Saakian, Alexander. "Improving energy efficiency of cold storage". АгроЭкоИнфо 3, n.º 45 (3 de junio de 2021): 12. http://dx.doi.org/10.51419/20213312.

Texto completo

Resumen

Saving resources and energy in refrigeration systems is one of the main vectors of development of the national economy of our country. One of the promising ways to solve these problems is the use of energy efficient refrigeration machines. The article discusses the main issues on the organization of energy efficient storage. In particular, the main recommendations for the design of the storage building are given; an analysis of the energy efficiency of refrigeration machines with and without VFD (variable frequency drive) is given; the main aspects of the operation of the condenser of the refrigeration unit are considered. Keywords: ANNUAL ENERGY CONSUMPTION, REGULATION, ENERGY EFFICIENCY

Los estilos APA, Harvard, Vancouver, ISO, etc.

25

Galimova, L. V., D. Z. Bayramov, A. A. Dyusengaliev y Sh Z. Bayramov. "ANALYSIS OF THE POSSIBILITY OF USING SECONDARY ENERGY RESOURCES IN FOOD INDUSTRY ENTERPRISES USING SPECIAL REFRIGERATION EQUIPMENT". Herald of Dagestan State Technical University. Technical Sciences 47, n.º 1 (21 de abril de 2020): 19–29. http://dx.doi.org/10.21822/2073-6185-2020-47-1-19-29.

Texto completo

Resumen

Abstract. Aim. Due to the current priority given to energy conservation issues, a promising research avenue in the field of refrigeration consists in the developing of energy-saving systems based on heat-recovery absorption refrigerators. The aim of the work is to study the possibility of using a water-ammonia absorption refrigeration machine to increase the efficiency of food production facilities.Method. Based on an analysis of the initial enterprise data, the possible operating modes of the refrigeration machine were determined considering the various types of heating and cooling sources proposed in the task specification. The identification of the characteristics of single-stage and twostage absorption schemes confirmed the possibility of increasing the enterprise's efficiency through the use of secondary energy resources. Results. The choice of initial data for the design of a singlestage absorption water-ammonia refrigeration machine (AVXM) was justified on the basis of a preliminary analysis carried out to calculate the size of the degassing interval. The calculation was carried out using a ξ – i diagram for the ammonia water solution. Conclusion. Two prior conditions for the design of a high-performance absorption water-ammonia refrigeration machine were determined on the basis of an analysis of four conditions set by the customer. For operating conditions with a low degassing interval value, a scheme for an absorption water-ammonia refrigeration machine employing two-stage absorption is proposed.

Los estilos APA, Harvard, Vancouver, ISO, etc.

26

Kothny., G. L. "AUXILIARIES: NEW MARINE REFRIGERATING MACHINE". Journal of the American Society for Naval Engineers 28, n.º 1 (18 de marzo de 2009): 238–47. http://dx.doi.org/10.1111/j.1559-3584.1916.tb00614.x.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

27

Ziliwu, Boby Wisely. "PERHITUNGAN BEBAN PENDINGINAN PADA SISTEM REFRIGERASI AIR BLAST FREEZER". JTT (Jurnal Teknologi Terapan) 6, n.º 2 (28 de octubre de 2020): 163. http://dx.doi.org/10.31884/jtt.v6i2.291.

Texto completo

Resumen

Refrigeration is an attempt to maintain the temperature level of a material or room at a level lower than the temperature of the surrounding environment by absorbing heat from the material or room. In short it can be said that refrigeration is the process of transferring heat from a material or another room. Basically, refrigeration technology is heat treatment. The refrigeration process is inseparable from the cooling load problem during the refrigeration machine operates. Excessive cooling load on a refrigeration unit will certainly have an effect that can accelerate the process of decomposition or deterioration in the quality of the catch. This research aims to calculate the cooling load of the blast freezer water and determine the refrigeration components of the blast freezer water unit. From the research results obtained, that the ship whose refrigeration system has a cooling power of 30 kW is able to cool fish as much as 3.5 tons (3,500 kg). With a cooling load of 1 ABF space of 28.54 kW with a fish mass of 3,500 kg. the COPactual achieved by the blast freezer water is about 2.8 smaller than the COPcarnot of 6.1.

Los estilos APA, Harvard, Vancouver, ISO, etc.

28

Nasruddin, M. Idrus Alhamid, Darwin R. B. Syaka y Arnas. "Experimental of Cascade Refrigeration System Using Natural Refrigerant Mixture Ethane and Carbon Dioxide at Low Temperature Circuit and Natural Refrigerant Propane at High Temperature Circuit". Applied Mechanics and Materials 388 (agosto de 2013): 96–100. http://dx.doi.org/10.4028/www.scientific.net/amm.388.96.

Texto completo

Resumen

Medicine and biomedical research activities require cold storage to store biomedical specimens such as, for example, stem cell, sperm, blood and other organs. During storage, to prevent the specimen from damage required a special cold storage reaches -80°C [1]. Using single cycle refrigeration machine can only reach -40°C, and performance deteriorates below -35°C drop in pressure associated with evaporation. Thus, to reach lower temperatures, use cascade refrigeration machine [2]. During this low-temperature circuit cascade refrigeration systems still use refrigerants that contain ozone-depleting or global warming (CFCs and HCFCs). To overcome this, a mixture of carbon dioxide and ethane azeotropic a promising alternative refrigerants. Simulation studies and experiments indicate a mixture of carbon dioxide and ethane were able to achieve the minimum temperature to -80°C [4-7]. With the mass ratio 70% R170 and 30% R744 circuit at low temperature refrigeration systems and uses a capillary tube expansion device 0.054 inch diameter with a length of 6 meters and 3 meters then use an electric heater as the cooling load. Cooling load is given by the variation of 90 W, 120 W and 150 W at a cabin in the low temperature circuit. From the experiment will be known characteristics of cascade refrigeration system with refrigerant mixture and will get the parameter data to make cascade refrigeration machine.

Los estilos APA, Harvard, Vancouver, ISO, etc.

29

Dardouch, J., M. Charia y A. Bernatchou. "Numerical study of a Solar Absorption Refrigeration Machine". E3S Web of Conferences 150 (2020): 01009. http://dx.doi.org/10.1051/e3sconf/202015001009.

Texto completo

Resumen

In this paper, we present a numerical study of a single-stage absorption refrigeration machine, operating with a couple of water-ammonia fluids, equipped with a distillation column and associated with a solar heating system using solar collectors. The study has showed the benefit of using the distillation column which is manifested by: The decrease of the operating temperature, The improvement of the coefficient of performance, Surface reduction of the solar collectors, The improvement of the solar coefficient of performance. The solar study shows that the absorption refrigeration machine equipped with a distillation column is better suited to solar energy with significantly better performance compared to the simple absorption refrigeration machine.

Los estilos APA, Harvard, Vancouver, ISO, etc.

30

Morosuk, Tatiana. "Structural and Parametric Optimization of an Absorption Refrigeration Machine: Inverse Rectification as Auxiliary Absorption Process". Defect and Diffusion Forum 258-260 (octubre de 2006): 219–24. http://dx.doi.org/10.4028/www.scientific.net/ddf.258-260.219.

Texto completo

Resumen

This paper discusses how the result of exergetic analysis should be used for improving efficiency of an absorption refrigeration machine. In the present work the process of inverse rectification as auxiliary absorption process in an absorption refrigeration machine is analyzed from the point of view of structural and parametric optimization.

Los estilos APA, Harvard, Vancouver, ISO, etc.

31

Kumbhar, Anil, Viveka Kaur y Dr Sunil S. Bhagwat. "Analysis of Vapor Absorption Refrigeration Machine Performance with Different Configuration of Water Supply". International Journal of Trend in Scientific Research and Development Volume-3, Issue-2 (28 de febrero de 2019): 76–79. http://dx.doi.org/10.31142/ijtsrd20275.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

32

Koritsoglou, Kyriakos, Vasileios Christou, Georgios Ntritsos, Georgios Tsoumanis, Markos G. Tsipouras, Nikolaos Giannakeas y Alexandros T. Tzallas. "Improving the Accuracy of Low-Cost Sensor Measurements for Freezer Automation". Sensors 20, n.º 21 (9 de noviembre de 2020): 6389. http://dx.doi.org/10.3390/s20216389.

Texto completo

Resumen

In this work, a regression method is implemented on a low-cost digital temperature sensor to improve the sensor’s accuracy; thus, following the EN12830 European standard. This standard defines that the maximum acceptable error regarding temperature monitoring devices should not exceed 1 °C for the refrigeration and freezer areas. The purpose of the proposed method is to improve the accuracy of a low-cost digital temperature sensor by correcting its nonlinear response using simple linear regression (SLR). In the experimental part of this study, the proposed method’s outcome (in a custom created dataset containing values taken from a refrigerator) is compared against the values taken from a sensor complying with the EN12830 standard. The experimental results confirmed that the proposed method reduced the mean absolute error (MAE) by 82% for the refrigeration area and 69% for the freezer area—resulting in the accuracy improvement of the low-cost digital temperature sensor. Moreover, it managed to achieve a lower generalization error on the test set when compared to three other machine learning algorithms (SVM, B-ELM, and OS-ELM).

Los estilos APA, Harvard, Vancouver, ISO, etc.

33

Yang, Wen-Jei, Shin Fann y John H. Kim. "Heat and Fluid Flow Inside Rotating Channels". Applied Mechanics Reviews 47, n.º 8 (1 de agosto de 1994): 367–96. http://dx.doi.org/10.1115/1.3111084.

Texto completo

Resumen

Power generation and refrigeration accomplished by means of rotating or reciprocating machinery. One of the basic elements of rotating machinery is the rotating channel system. With the desire for ever increasing efficiency in power generation and refrigeration, higher or lower operating temperatures are achieved. It has provided motivation for the pursuit of knowledge on heat transfer and fluid flow characteristics. This paper reviews the literature pertinent to studies of fluid flow and/or heat transfer in channel flows subjected to radial rotation, parallel rotation, and coaxial revolution. Special problems unique to rotating systems are discussed and future study areas are suggested.

Los estilos APA, Harvard, Vancouver, ISO, etc.

34

Ben Zid, Nihel, Nejib Hajji y Mohamed El Ganaoui. "COP enhancement and comparison of different absorption cooling systems". MATEC Web of Conferences 330 (2020): 01032. http://dx.doi.org/10.1051/matecconf/202033001032.

Texto completo

Resumen

The absorption refrigeration machines represent a good alternative to compression refrigeration machines but the major problem of this type of refrigeration lies in the COP, which seems to be less efficient. Several researches are carried out to improve the performances of these machines such as the combination with the technology of the ejectors. In this work, we are interested in the three ammonia-water absorption cycles: Single effect absorption, Ejector-absorption and Combined ejector-flash tank absorption cycles. A gas-gas ejector would be installed between the generator and the condenser. We suppose that adding a flash tank between the condenser and the evaporator could help improve the entrainment ratio of the ejector. We used simulations in order to compare the performances of these three different cycles. The simulation results demonstrate that the combined ejector-flash tank absorption cycle performs better than others.

Los estilos APA, Harvard, Vancouver, ISO, etc.

35

Sharapov, Irek, Sergey Vizgalov, Timur Mustafin y Ibragim Khisameev. "A turbocompressor refrigeration machine characteristics’ calculation". IOP Conference Series: Materials Science and Engineering 604 (3 de septiembre de 2019): 012047. http://dx.doi.org/10.1088/1757-899x/604/1/012047.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

36

Коновалов, Дмитро Вікторович, Роман Миколайович Радченко, Сергій Георгійович Фордуй, Віктор Павлович Халдобін, Олексій Олегович Зєліков y Олександр Анатолійович Різун. "ВДОСКОНАЛЕННЯ ТЕПЛОВИКОРИСТОВУЮЧИХ ЕЖЕКТОРНИХ ХОЛОДИЛЬНИХ МАШИН ЗАСТОСУВАННЯМ АЕРОТЕРМОПРЕСОРНИХ ТЕХНОЛОГІЙ". Aerospace technic and technology, n.º 1 (26 de febrero de 2021): 60–66. http://dx.doi.org/10.32620/aktt.2021.1.06.

Texto completo

Resumen

The paper shows and analyzes circuit solutions for improving the existing schemes of ejector heat-using refrigeration machines, which are used as part of cogeneration plants. One of the promising areas is the use of an aerothermopressor, which implements the effect of thermogasdynamic compression, which is to increase the pressure while reducing the temperature in the evaporation of liquid, which injected into the flow of vapor moving at speed near the sound. To analyze the efficiency of ejector refrigeration machines, the developed calculation model was used, which takes into account the use of an aerothermopressor in the cycles of refrigeration machines with the features of the calculations of cycles and circuits. To select and determine possible circuit solutions, the efficiency of an aerothermopressor for different refrigerants was evaluated and a comparative analysis of the characteristic parameters of the efficiency of an aerothermopressor in the range of cooling temperature differences is 20–100 oC was made. It is possible to increase the efficiency of ejector heat-using refrigeration machines when using an aerothermopressor by providing a temperature difference of 60–100 oC. The analysis showed that the most important are: R717, R134a, R227ea, R1234ze (E), R1234yf (2–4%). It is possible to provide a higher thermal coefficient for ejector heat-using refrigeration machines by using an aerothermopressor in the circuit using the circulation of liquid refrigerant. The corresponding increase in the thermal coefficient is 1.5–2.0%. The use of an aerothermopressor in the scheme with heat recovery allows removing additional overheating of vapor before suctioning into the ejector with a corresponding increase in the thermal coefficient by 4-8%. The analysis shows that the total increase in the thermal coefficient due to the combined use of an aerothermopressor, heat recovery, and recirculation is 10–15% at a base value of 0.30–0.40.

Los estilos APA, Harvard, Vancouver, ISO, etc.

37

Baglivo, Cristina, Paolo Maria Congedo y Pasquale Antonio Donno. "Analysis of Thermodynamic Cycles of Heat Pumps and Magnetic Refrigerators Using Mathematical Models". Energies 14, n.º 4 (9 de febrero de 2021): 909. http://dx.doi.org/10.3390/en14040909.

Texto completo

Resumen

This paper proposes a critical review of the different aspects concerning magnetic refrigeration systems, and performs a detailed analysis of thermodynamic cycles, using mathematical models found in the literature. Langevin’s statistical mechanical theory faithfully describes the physical operation of a refrigeration machine working according to a magnetic Ericsson cycle. Results of mathematical and real experimental models are compared to deduce which best describes the Ericsson cycle. The theoretical data are not perfectly consistent with the experimental data; there is a maximum deviation of about 30%. Numerical and experimental data confirm that very high Coefficient of Performance (COP) values of more than 20 can be achieved. The analysis of the Brayton cycle consisted of finding the mathematical model that considers the irreversibility of these machines. Starting from the thermodynamic properties of magnetocaloric materials based on statistical mechanics, the efficiency of an irreversible Brayton regenerative magnetic refrigeration cycle is studied. Considering the irreversibility in adiabatic transformations, the lower limit of the optimal ratio of two magnetic fields is determined, obtaining a valid optimization criterion for these machines operating according to a Brayton cycle. The results show that the Ericsson cycle achieves a higher Coefficient of Performance than the Brayton cycle, which has a higher cooling capacity as it operates with a larger temperature difference between the magnetocaloric material and source.

Los estilos APA, Harvard, Vancouver, ISO, etc.

38

Coral, Rodrigo, Carlos A. Flesch, Cesar A. Penz y Maikon R. Borges. "Development of a Committee of Artificial Neural Networks for the Performance Testing of Compressors for Thermal Machines in Very Reduced Times". Metrology and Measurement Systems 22, n.º 1 (1 de marzo de 2015): 79–88. http://dx.doi.org/10.1515/mms-2015-0003.

Texto completo

Resumen

Abstract This paper presents a new test method able to infer - in periods of less than 7 seconds - the refrigeration capacity of a compressor used in thermal machines, which represents a time reduction of approximately 99.95% related to the standardized traditional methods. The method was developed aiming at its application on compressor manufacture lines and on 100% of the units produced. Artificial neural networks (ANNs) were used to establish a model able to infer the refrigeration capacity based on the data collected directly on the production line. The proposed method does not make use of refrigeration systems and also does not require using the compressor oil.

Los estilos APA, Harvard, Vancouver, ISO, etc.

39

Радченко, Андрій Миколайович. "МЕТОД ВИЗНАЧЕННЯ ХОЛОДОПРОДУКТИВНОСТІ ТЕРМОТРАНСФОРМАТОРА ЗА МАКСИМАЛЬНИМ ТЕМПОМ ПРИРОЩЕННЯ ТЕРМОЧАСОВОГО ПОТЕНЦІАЛУ ОХОЛОДЖЕННЯ ПОВІТРЯ". Aerospace technic and technology, n.º 4 (14 de octubre de 2018): 53–57. http://dx.doi.org/10.32620/aktt.2018.4.07.

Texto completo

Resumen

It is proved a possibility of using the thermohour cooling potential method, developed by the author, for defining the installed (design) refrigeration capacity of term transformer (refrigeration machine), providing a maximum rate of thermo-hour cooling potential increasing according to the current climatic conditions for a definite period of operation.It is proposed to define the effect, gained due to cooling air, in particular at the inlet of GTU, depends on duration and depth of cooling, by thermohour potential ÕS,°С·h, as air temperature decrease Δta multiplied by duration τ of GTU operation at decreased temperature: ÕS = ∑(Δta ∙°τ), which to some extent characterizes heat load on the cooling system.It is shown that taking into consideration a different rate of annual thermohour cooling potential arising with increasing the installed refrigeration capacity of term transformer, caused by changing the heat load according to current climatic conditions during a year, it is necessary to choose such design heat load on the air cooling system (refrigeration capacity of term transformer) that provides a maximum value of annual thermohour cooling potential or close it with relatively high rates of its increasing. To define the installed refrigeration capacity, providing a maximum rate of annual thermohour cooling potential increasing, it is analyzed the dependence of annual thermohour cooling potential related to the installed refrigeration capacity of term transformer, from the installed refrigeration capacity of term transformer. As a result of the investigation, it is proposed the method of defining the design heat load (installed refrigeration capacity) of term transformer with maximum rates of increasing thermohour cooling potential, as a further development of methodology of rational designing of them transformers for combustion engine inlet air cooling on the base of thermohour potential, developed by author

Los estilos APA, Harvard, Vancouver, ISO, etc.

40

Shelgunov, A. V. "Comparative analysis of stand-alone co-generation and tri-generation energy centres". Power and Autonomous equipment 2, n.º 3 (30 de octubre de 2019): 129–40. http://dx.doi.org/10.32464/2618-8716-2019-2-3-129-140.

Texto completo

Resumen

Introduction: presently, versatile stand-alone sources of electric energy serve as vehicles used to solve the problem of electric energy delivery to remote customers and to reduce substantial energy losses in the process of its delivery. The main principles underlying energy centres encompass generation, co-generation, and tri-generation.Methods: the author has performed a comparative analysis of the energy centres in operation on different principles. As for electric energy generation, the author has analyzed gas-reciprocating units consuming natural gas as the most economical fuel. The process of electric energy and heat co-generation is exemplified by four types of co-generators. The analysis of energy centres that comprise tri-generators consuming thermal energy, generated by the co-generator to produce cooled water (cold), is based on research into vapour compression refrigerating machines, consuming electric energy, and absorption refrigerating machines, consuming thermal energy. The comparative analysis of performance efficiency demonstrated by versatile energy centres (a co-generation gasreciprocating unit and a tri-generation energy centre, having an absorption refrigerating machine) is based on an annual energy consumption chart of a shopping centre located in central Russia.Results and discussion: the author has identified the strengths and weaknesses of energy generators, using different principles of energy generation; the author has analyzed their process charts and identified their application areas.Conclusion: the author stresses the importance of analytics and comparisons to be applied as part of the energy equipment selection procedure to assure high-quality operation of energy consumers.

Los estilos APA, Harvard, Vancouver, ISO, etc.

41

Kolosov, M. A. "Theorem of Ideal Cycles of Refrigerating Machines". Chemical and Petroleum Engineering 51, n.º 9-10 (enero de 2016): 674–82. http://dx.doi.org/10.1007/s10556-016-0104-x.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

42

Vasilescu, Elena Eugenia, Rahal Boussehain y Michel Louis Feidt. "Exergy analysis of an adsorption refrigeration machine". International Journal of Exergy 4, n.º 2 (2007): 197. http://dx.doi.org/10.1504/ijex.2007.012066.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

43

Stuart, M. C. "Test of Two-Ton Clothel Refrigerating Machine". Journal of the American Society for Naval Engineers 31, n.º 3 (18 de marzo de 2009): 624–33. http://dx.doi.org/10.1111/j.1559-3584.1919.tb00817.x.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

44

Wang, Fengzhe. "A Fast Drying Machine Based On Semiconductor Heat Pump". E3S Web of Conferences 252 (2021): 02024. http://dx.doi.org/10.1051/e3sconf/202125202024.

Texto completo

Resumen

The new latent heat recovery type semiconductor heat pump ground fast dryer is a kind of integrated semiconductor refrigeration module on the traditional dryer. We simulated the process of the wind being heated by the hot end of the semiconductor refrigeration module under different working conditions through ANSYS software, so as to obtain the best solution for the semiconductor refrigeration module. Using the principles of drying and air condensation, we calculated the influence of the drying rate, drying time, and the condensation effect of the cold end when the air at different hot end inlet wind speeds, ambient temperature and moisture content blows the same amount of moisture on the ground. Through energy-saving analysis, our design saves about 60% energy compared with traditional electric heating style hair dryers. In the case of the same input power, the outlet air temperature of the semiconductor heat pump ground rapid dryer is significantly higher than that of the electric heating hair dryer. Therefore, when the ground is dry with the same amount of moisture, the use of the new semiconductor heat pump ground rapid dryer can significantly shorten drying time, the best drying time shortening rate is as high as 70%.

Los estilos APA, Harvard, Vancouver, ISO, etc.

45

Arias, J. y P. Lundqvist. "Modelling and experimental validation of advanced refrigeration systems in supermarkets". Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 219, n.º 2 (1 de mayo de 2005): 149–56. http://dx.doi.org/10.1243/095440805x8593.

Texto completo

Resumen

The effective use of energy and the replacement of CFC and HCFC refrigerants are two factors that have influenced the design and operation of refrigeration systems in supermarkets during recent years. The potential for increasing energy efficiency in refrigeration systems, indoor climate and refrigerated cabinets is large. Since the energy systems of a supermarket are relatively complex, improvements in one subsystem affect other systems, thus making analysis of potential improvements non-additive. A computer model, CyberMart, that predicts building heating and cooling loads, HVAC (heating, ventilation, and air conditioning), and refrigeration system performances of a supermarket, has been developed. The focus of the model is on energy use, environmental impact (TEWI), and life cycle cost (LCC) of the refngeration system. The refrigeration system solutions included in the model are: direct system, completely indirect system, partially indirect system, cascade system, parallel system with mechanical sub-cooling (where the refrigerant in the low-temperature system is sub-cooled with the brine of the intermediate temperature level), and district cooling (that cools the condenser of the refrigeration machines). Measurements of different parameters such as outdoor and indoor temperatures, relative humidity, and compressor power have been carried out in several stores to validate the model. A theoretical description of the model and results from the model and measurements are presented in this paper.

Los estilos APA, Harvard, Vancouver, ISO, etc.

46

Bulanov, Nikolay V., Ekaterina I. Avksentyeva y Viktor G. Bondarenko. "Prospects for the development of air conditioning technology in transport with internal combustion engines". Innotrans, n.º 4 (2020): 67–71. http://dx.doi.org/10.20291/2311-164x-2020-4-67-71.

Texto completo

Resumen

To achieve comfortable operating conditions, the car is equipped with air conditioning. The most common air conditioning devices in transport are air conditioners made on the basis of steam compression refrigerating machines. However, due to the introduction of virtually silent compressors of various capacities on the market, it became possible to return to the use of the simplest and cheapest method of air conditioning – using air-cooled machines. Their use will reduce overall equipment costs, make operation much easier, and increase the reliability of the equipment. The use of sorption refrigerating machines should be considered the most promising, since this will reduce fuel costs by using the energy emitted by the car along with hot exhaust gases.

Los estilos APA, Harvard, Vancouver, ISO, etc.

47

Tyczewski, Przemysław. "Investigation of the influence of Ti-Al-Cr-N coating on the surface condition of cooling compressor elements". AUTOBUSY – Technika, Eksploatacja, Systemy Transportowe 19, n.º 12 (31 de diciembre de 2018): 685–88. http://dx.doi.org/10.24136/atest.2018.478.

Texto completo

Resumen

Elements of refrigeration compressors, may be exposed to various types of wear processes. The presence of the refrigerant makes the lubricating and anti-wear properties of the oil-medium mixture much worse than the oil without refrigerant. The paper presents the effect of using the Ti-AI-Cr-N coating on the surface condition of friction junction occurring in compressors of chillers. The tests were carried out using a model friction machine simulating the element of a refrigeration compressor.

Los estilos APA, Harvard, Vancouver, ISO, etc.

48

Zhou, Can y Yu Yun Li. "Multiple Criteria Decision Method Used in Selection of Green Air-Conditioning System". Advanced Materials Research 732-733 (agosto de 2013): 605–8. http://dx.doi.org/10.4028/www.scientific.net/amr.732-733.605.

Texto completo

Resumen

Established a hierarchy structure model and made a quantitative assessment of seven air-conditioning systems which are gas boiler plus electric refrigerating system、air-cooled heat pump、variable refrigerant volume air conditioning、ground-source heat pump air conditioning、centralized heat-supply plus electric refrigerating、gas direct-fired machine、energy storage on relevant professionality and indoor environment,initial investment,operating costs,operation and management,environmental impact,energy consumption.Finally we obtained an optimal scheme,which agreed with that in practice.

Los estilos APA, Harvard, Vancouver, ISO, etc.

49

Ben Zid, Nihel, Mohammed El Ganaoui y Nejib Hajji. "Simulation and comparison of combined ejector-absorption and single effect absorption refrigeration systems". MATEC Web of Conferences 307 (2020): 01008. http://dx.doi.org/10.1051/matecconf/202030701008.

Texto completo

Resumen

Refrigeration by absorption is gaining more and more importance nowadays especially in applications where the source of energy used in the generator is renewable. However the major problem of this type of refrigeration lies in the COP, which seems to be weaker than compression machines. The use of an ejector is one of the means that can help overcome this problem. In this work, we are interested in the ammonia-water absorption cycle comprising a gas-gas ejector interposed between the generator and the condenser. We suppose that adding a flash tank between the condenser and the evaporator could help improve the entrainment ratio of the ejector. Simulations using the Hysys software are performed in order to look for the optimal conditions for the work of this machine and to make a comparison in terms of performance with single effect cycles. Results showed a significant improvement in the COP and proved therefore that it has better performance than single effect cycles.

Los estilos APA, Harvard, Vancouver, ISO, etc.

50

Tyczewski, Przemysław y Jarosław Chmiel. "The Influence of Liquid Refrigerant on Refrigerating Compressors Sliding Surfaces". Solid State Phenomena 252 (julio de 2016): 111–20. http://dx.doi.org/10.4028/www.scientific.net/ssp.252.111.

Texto completo

Resumen

Reasons of compressors failures are connected with different operating conditions of individual parts. One of compressor damage reasons is pouring it over with liquid refrigerant. The purpose of this work was to carry out tests concerning the influence of refrigerant being in the liquid phase on piston compressor sliding surfaces. Tests were carried out in the mixture of synthetic polyester oil with liquid refrigerant R134a. The tests were performed with the use of the friction machine and the pair type block-on-ring simulating the refrigerating compressor inside and with the use of the real refrigerating compressor. The obtained results confirm the unfavourable influence of liquid refrigerant on friction elements in the refrigerating compressor. The role of hydrodynamic phenomena in the development of damage to the compressors has been showed.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Artículos de revistas sobre el tema "Refrigeration and refrigerating machinery Refrigeration and refrigerating machinery Refrigeration and refrigerating machinery"

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros