To see the other types of publications on this topic, follow the link: Design of flue-gas duct.
Journal articles on the topic 'Design of flue-gas duct'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Design of flue-gas duct.'
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 journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Ramsunkar, Charlene, Chris van Tonder, and Walter Schmitz. "Errors Associated With Excess Air Multipoint Measurement Systems." Chemical and Process Engineering 36, no. 4 (December 1, 2015): 405–23. http://dx.doi.org/10.1515/cpe-2015-0029.
Full textAbstract:
Abstract Boiler combustion air is generally controlled by the excess air content measured at the boiler economiser outlet using oxygen (O2) analysers. Due to duct geometry and dimensions, areas of high and low O2 concentrations in the flue gas duct occur, which poses a problem in obtaining a representative measurement of O2 in the flue gas stream. Multipoint systems as opposed to single point systems are more favourable to achieve representative readings. However, ash blockages and air leakages influence the accuracy of O2 measurement. The design of multipoint system varies across ESKOMs’ Power Stations. This research was aimed at evaluating the accuracy of the multipoint oxygen measurement system installed at Power Station A and to determine the systematic errors associated with different multipoint systems designs installed at Power Stations' A and B. Using flow simulation software, FloEFDTM and Flownex®, studies were conducted on two types of multipoint system designs This study established that significantly large errors, as high as 50%, were noted between the actual and measured flue gas O2. The design of the multipoint system extraction pipes also introduces significant errors, as high as 23%, in the O2 measured. The results indicated that the sampling errors introduced with Power Station A’s system can be significantly reduced by adopting the sampling pipe design installed at Power Station B.
2
Deng, Jia-jia, Liang-ming Pan, De-qi Chen, Yu-quan Dong, Cheng-mu Wang, Hang Liu, and Mei-qiang Kang. "Numerical simulation and field test study of desulfurization wastewater evaporation treatment through flue gas." Water Science and Technology 70, no. 7 (August 26, 2014): 1285–91. http://dx.doi.org/10.2166/wst.2014.359.
Full textAbstract:
Aimed at cost saving and pollution reduction, a novel desulfurization wastewater evaporation treatment system (DWETS) for handling wet flue gas desulfurization (WFGD) wastewater of a coal-fired power plant was studied. The system's advantages include simple process, and less investment and space. The feasibility of this system has been proven and the appropriate position and number of nozzles, the spray droplet size and flue gas temperature limitation have been obtained by computational fluid dynamics (CFD) simulation. The simulation results show that a longer duct, smaller diameter and higher flue gas temperature could help to increase the evaporation rate. The optimal DWETS design of Shangdu plant is 100 μm droplet sprayed by two nozzles located at the long duct when the flue gas temperature is 130 °C. Field tests were carried out based on the simulation results. The effects of running DWETS on the downstream devices have been studied. The results show that DWETS has a positive impact on ash removal efficiency and does not have any negative impact on the electrostatic precipitator (ESP), flue gas heat exchanger and WFGD. The pH values of the slurry of WFGD slightly increase when the DWETS is running. The simulation and field test of the DWETS show that it is a feasible future technology for desulfurization wastewater treatment.
3
Kurkus-Gruszecka, Michalina, Piotr Krawczyk, and Janusz Lewandowski. "Numerical Analysis on the Flue Gas Temperature Maintenance System of a Solid Fuel-Fired Boiler Operating at Minimum Loads." Energies 14, no. 15 (July 22, 2021): 4420. http://dx.doi.org/10.3390/en14154420.
Full textAbstract:
Currently, energy policy is associated with the increase in the share of renewable sources in systemic energy production. Due to this trend, coal-fired power units must increase their work flexibility. Adapting a coal power plant to work with a lower load often causes the issue of maintaining the temperature before the selective catalytic reduction (SCR) installation at a sufficiently high level. This paper presents a CFD analysis of the mixing area of two flue gas streams before the SCR installation with various methods for mixing flue gas streams. The novelty of the work is mixing the flue gas streams of different temperatures using a flap shape developed by the authors. A series of numerical simulations were performed to develop the location and method of introducing the higher temperature gas, obtaining a uniform distribution of the exhaust gas temperature. The simulation scheme was applied to a series of geometrical modifications of the boundary conditions. The tested solution using only a single, straight flap in the flue gas duct allows the amplitude to be reduced from 298 K to 144 K. As a result of the research, a mixing flap design was developed to reduce the initial temperature amplitude of the flue gas streams from 298 K to 43 K.
4
Wang, Jia Qiong, and Fan Yu Kong. "Study Analysis on Purification of Alumina Electrolytic Flue Gas by Bag Filter." Applied Mechanics and Materials 130-134 (October 2011): 904–7. http://dx.doi.org/10.4028/www.scientific.net/amm.130-134.904.
Full textAbstract:
To improve the shortcoming in bag filter design in China (mainly used in purification of HF in alumina electrolytic flue gas), necessity of basic theoretical study on bag-filter used in purification of alumina electrolytic flue gas is analyzed. Four study aspects are proposed , which includs flow field optimization, influences of bag length and process parameter on forming dust layer, properties of the dust layer adsorbing hydrogen. Some primary study is done. This will provide a reference for engineering design and process operation.
5
Xing, Futang, Yuheng Li, Dan Mei, Shunfeng Gui, and Liya Wang. "Optimized design for heavy mound venturi." Thermal Science 21, no. 4 (2017): 1873–78. http://dx.doi.org/10.2298/tsci161201102x.
Full textAbstract:
The venturi scrubber is one of the most efficient gas cleaning devices for removal of contaminating particles in industrial flue-gas purification processes. The velocity of the gas entering the scrubber is one of the key factors influencing its dust-removal efficiency. In this study, the shapes of the heavy mound and tube wall are optimized, allowing the girth area to become linearly adjustable. The resulting uniformity of velocity distribution is verified numerically.
6
Rumyantsev, D. V., L. V. Krupnov, R. V. Starykh, R. A. Marchuk, and V. B. Fomichev. "Using shell-type tuyeres at Pierce–Smith horizontal converters of the Nadezhda Metallurgical Plant." Izvestiya Vuzov Tsvetnaya Metallurgiya (Universities Proceedings Non-Ferrous Metallurgy) 1, no. 1 (February 11, 2021): 16–27. http://dx.doi.org/10.17073/0021-3438-2021-1-16-27.
Full textAbstract:
Since 2015 the processing capacity reconfiguration at the Polar Branch of MMC Norilsk Nickel (hereinafter PB) sets new goals for conventional pyrometallurgical processes of smelting and converting. The design flowsheet of Kolesnikov Nadezhda Metallurgical Abstract: Plant (hereinafter NMP) provided for «cross-converting» when copper matte was first processed in one converter to produce blister copper followed by nickel matte processing to yield copper-nickel converter matte bypassing the discharge of dry coagulated slag. This flowsheet allowed for converter heat balance optimization, decreasing the formation of refractory reverts and significant extension of the converter campaign. PB Nickel Plant shutdown resulted in copper processing elimination at NMP and switching the converters to the conventional nickel converting flowsheet. In turn, it gave rise to the need for solutions to extend converter campaign while maintaining the possibility to process large amounts of nickel slag from the second converting stage at the PB Copper Plant. For this purpose the series of lab experiments were carried out to develop the technology and design documentation for the system to supply oxygen-enriched air (up to 45 %) to horizontal converters using shell-type tuyeres. In addition, literature data were analyzed on this topic along with the experience of smelters in this area. Process design calculations were done. The efforts were taken in cooperation with the PB engineering personnel and Laboratory of Pyrometallurgy of LLC «Gipronickel Institute». The use of reduced diameter shell-type tuyeres to inject the oxygen-air mixture was found to decrease the converter blowing and off-gas volumes. The decline in off-gas quantity leads to reduced heat load on the converter mouth and flue duct system, as well as to lowered converter dust entrainment. The use of oxygen-enriched blowing implies the higher smelt heating rate. Excess heat compensation requires timely charging of cold reverts and flux. In emergencies (if cold reverts are not available) the oxygen content of the blowing has to be reduced until switching over to air blowing. The series of the above efforts will offer a possibility to use the shell-type tuyeres keeping the converter off-gas temperature at the current level. Thus continuous monitoring and efficient control will ensure the off-gas temperature and volume at the inlets of gas cooling and cleaning systems not exceeding the limiting values. The introduction of the reduced diameter shell-type tuyeres for air-oxygen mixture injection does not require any upgrade of the existing gas cooling and cleaning systems. Moreover, switching to these tuyeres will reduce gas load on the flue duct system and heat load on the water-cooled dust cap, lower dust entrainment and non-recoverable dust losses after the gas cleaning system.
7
Machnik, Ryszard, and Łukasz Więckowski. "Operational tests of an electrostatic precipitator reducing low dust emission from solid fuels combustion." Eksploatacja i Niezawodnosc - Maintenance and Reliability 23, no. 3 (July 5, 2021): 569–74. http://dx.doi.org/10.17531/ein.2021.3.18.
Full textAbstract:
The article presents the continuation of the research aimed at designing, manufacturing and selecting the operating parameters of the electrostatic precipitator for household applications. The tests were carried out in the laboratory and real conditions. The object of the research was a pre-production prototype of the electrostatic precipitator installed in the flue gas duct of a single-family building. The source of exhaust gases was a coal-fired, low-temperature water heating boiler with a nominal power of 21 kW (old generation boiler-year of production: 2007). The obtained results showed that the adopted design of the electrostatic precipitator enables the reduction of dust emissions generated in the combustion of solid fuels in households at relatively low operating costs.
8
Yang, Li Jun. "Supervisory Control of Silicon Steel Plant Dust Removal System Based on Configuration Technology." Advanced Materials Research 756-759 (September 2013): 452–57. http://dx.doi.org/10.4028/www.scientific.net/amr.756-759.452.
Full textAbstract:
This paper introduces the real-time monitoring provided by the function of PLC control system based on the configuration control technology in silicon steel plant. Visual real-time monitoring of silicon steel flue gas dust removal system, the main parameters includes: working condition of the two temperature sensor in flue pipe, air conditioning butterfly valve, bag type dust trap system, high pressure fan, dust conveying system, dust unloading system and cleaning system, etc. Moreover, monitoring and give an alarm in case the failure of dust removal system appears appears in the course of their work. This paper also introduces the hardware components and software components of the visual real-time monitoring of silicon steel flue gas dust removal system, and their applications. And discuss how to use configuration technology develop and design real-time monitoring system.
9
Meneses Chacón, Edxon Stiven, Julián Ernesto Jaramillo-Ibarra, and Elisabet Mas de les Valls. "Numerical analysis of the thermal and fluid dynamic behavior of the flue gases in a traditional furnace for panela production." INGE CUC 15, no. 1 (June 8, 2019): 133–41. http://dx.doi.org/10.17981/ingecuc.15.1.2019.12.
Full textAbstract:
Introduction: Panela is a product derived from sugar cane that is prepared using a traditional burner designed especially for this purpose. According to studies found in the literature, it was identified that the thermal efficiency of panela burners is 30% on average.
Objective: The objective of this investigation is to contribute to the search for new alternatives for the improvement of the low efficiency present on these systems, mainly affecting the flue gases duct.
Methodology: The development of this study is as follows: first, a research of the radiation and optical thickness effect in a simplified furnace is carried out. Afterward, a series of simulations with modifications in the design of the flue gas duct for a real size furnace are analyzed.
Results: The results showed that the radiation effect must be considered and, even though the optical thickness is low, it has a relevant impact in the heat transfer process due to the high temperatures in the furnace. A chaotic movement of the gases implied more heat transferred to the heaters and high values of Nusselt with the addition of new elements in the duct were obtained.
Conclusions: Arrangement 1, provides the best results with a Nusselt and thermal efficiency increase. No significant differences between the DOM and the P-1 radiation were found.
10
Jugănaru, Daniela-Elena, Mariana Panaitescu, and Liviu-Constantin Stan. "COMPARATIVE CFD BASED PARAMETRIC ANALYSIS OF GAS FLOW IN TWO CONTER-FLOW WET SCRUBBER SYSTEMS." Journal of marine Technology and Environment 1, no. 2021 (2021): 28–32. http://dx.doi.org/10.53464/jmte.01.2021.04.
Full textAbstract:
" In this study, gas flow field were simulated using ANSYS 2020R2, Fluid Flow Fluent computational fluids dynamic (CFD) software based on the continuity, velocity, temperature, energy and k - turbulence. The overall objective of the study is to compare the pressure and velocity maps inside the wet scrubber system for two different scrubber designs. I have choose to analyse an In-Line scrubber bottom inlet, type I, and In-Line scrubber side inlet, type L. Bottom entry or side entry designs to allow a direct up-flow configuration and simplify engine exhaust gas duct routing for any type of vessel. The flow in a wet scrubber is very complex due to the interaction between dust particles, water droplets, and bulk water and flue gas. The flue gas flow is turbulent and there are multiple phases (gas, liquid and solid). CFD codes that predict gas flow patterns are based on conservation equations for mass, momentum and energy. The results show that the residuals have a very good job of converging at minimum flow contours and vectors at the inlet across the scrubbing chamber and outlet shows a distributed flow. The velocity profiles have fully conformed to the recommended profile for turbulent flow in pipes. As can be seen in the figures above, the velocity flow contour inside the scrubber is higher in the scrubber side inlet. Even though I choose to study the simplified scrubber model without taking into account that spray nozzle improve mixing between the scrubbing liquid and waste gas; from the results obtained, it can be deduced that the numerical simulation using CFD is an effective method to study the flow characteristics of a counter-flow wet scrubber system. "
11
Knezevic, Suzana, Rade Karamarkovic, Vladan Karamarkovic, and Nenad Stojic. "Radiant recuperator modelling and design." Thermal Science 21, no. 2 (2017): 1119–34. http://dx.doi.org/10.2298/tsci160707232k.
Full textAbstract:
Recuperators are frequently used in glass production and metallurgical processes to preheat combustion air by heat exchange with high temperature flue gases. Mass and energy balances of a 15 m high, concurrent radiant recuperator used in a glass fiber production process are given. The balances are used: for validation of a cell modeling method that predicts the performance of different recuperator designs, and for finding a simple solution to improve the existing recuperator. Three possible solutions are analyzed: to use the existing recuperator as a countercurrent one, to add an extra cylinder over the existing construction, and to make a system that consists of a central pipe and two concentric annular ducts. In the latter, two air streams flow in opposite directions, whereas air in the inner annular passage flows concurrently or countercurrently to flue gases. Compared with the concurrent recuperator, the countercurrent has only one drawback: the interface temperature is higher at the bottom. The advantages are: lower interface temperature at the top where the material is under maximal load, higher efficiency, and smaller pressure drop. Both concurrent and countercurrent double pipe-in-pipe systems are only slightly more efficient than pure concurrent and countercurrent recuperators, respectively. Their advantages are smaller interface temperatures whereas the disadvantages are their costs and pressure drops. To implement these solutions, the average velocities should be: for flue gas around 5 m/s, for air in the first passage less than 2 m/s, and for air in the second passage more than 25 m/s.
12
Khairunnissa, Isni Nur, Prima Besty Asthary, Saepulloh Saepulloh, and Rahmaniar Mulyani. "Pemanfaatan Air Limbah Wet Scrubber Flue Gas Desulphurization (FGD) Industri Kertas sebagai Medium Pertumbuhan Spirulina platensis." JURNAL SELULOSA 8, no. 02 (December 31, 2018): 95. http://dx.doi.org/10.25269/jsel.v8i02.239.
Full textAbstract:
Proses flue gas desulohurization (FGD) dengan wet scrubber adalah suatu proses untuk menurunkan konsentrasi SOx gas buang hasil pembakaran. Proses inidapat mengatasi polusi udara dengan cara menurunkan emisi gas dan partikel debu sehingga menghasilkan gas buangan yang lebih bersih. Air limbah wet scrubber bersifat asam. Salah satu alternatif pemanfaatan air limbah wet scrubber adalah untuk budidaya mikroalga. Spirulina platensis merupakan mikroalga yang berwarna hijau kebiruan yang mempunyai nilai gizi tinggi. Penelitian ini bertujuan untuk mengetahui potensi air limbah wet scrubber sebagai medium pertumbuhan S. platensis dan untuk mengetahui konsentrasi air limbah yang optimum bagi pertumbuhan S. platensis. Metode yang digunakan adalah Rancangan Acak Lengkap (RAL) dengan 5 perlakuan dan 5 ulangan. Air limbah wet srubber dengan konsentrasi 0%, 25%, 50%, 75%, dan 100% digunakan sebagai medium pertumbuhan S. platensis. Selama kultivasi, dilakukan pengamatan pH, produksi biomassa, dan kandungan fikosianin. Hasil menunjukkan bahwa air limbah wet scrubber dapat dimanfaatkan sebagai medium pertumbuhan S. platensis. Konsentrasi optimum bagi pertumbuhan S. platensis adalah campuran dari 75% air limbah wet scrubber dan 25% medium Zarrouk.Kata kunci : air limbah, flue gas desulphurization, wet scrubber, Spirulina platensis Utilization of Wet Scrubber Wastewater from Flue Gas Desuphurization (FGD) of Paper Industry as a Growth Medium for Spirulina platensisAbstractThe flue gas desulohurization (FGD) withwet scrubber is a process to reduce the concentration of SOx of the flue gas from combustion. This process can resolve the air pollution by reducing gas emission and the dust particles in the liquid droplets to produce cleaner flue gas. The wet scrubber wastewater is acidic. An alternative utilization of wet scrubber wastewater is for cultivation of microalgae. Spirulina platensis is bluish-green microalgae containing high nutritional value. The objective of this research is to determine the potential and the optimum concentration of wastewater from wet scrubber as growth medium of Spirulina. platensis. The research method was observation in the laboratory with a completely randomized design (CRD) with 5 treatments and 5 repetitions. The wastewater from wet scrubber with a concentration of 0 %, 25 %, 50 %, 75 %, and 100 % was used as growth medium of S. platensis. During cultivation, pH, biomass production, and pigment phycocyanin were measured. The results indicated that the wastewater of wet scrubber can be utilized as a growth medium of S. platensis. The optimum concentration for the growth of S. platensis is the mixture of 75% of the wastewater from wet scrubber and 25% of medium Zarrouk.Keywords : wastewater, flue gas desulphurization, wet scrubber, Spirulina platensis
13
Matas, Richard, Martin Novák, and Jindřich Kňourek. "Numerical Simulations of Flow in Electrostatic Precipitators." MATEC Web of Conferences 328 (2020): 02021. http://dx.doi.org/10.1051/matecconf/202032802021.
Full textAbstract:
Electrostatic precipitators are widely used in power generation and industry to separate solid particles from flue gases. They need relatively homogeneous distribution of the flue gas inside otherwise the required efficiency cannot be ensured. The paper shows how to approach some of possible troubles with distribution of the stream inside of the filters caused by unsuitable design of ducts in front of the device or by inlet parts of filters. Three filters in operation are presented as examples which seem to be similar, but their behaviour is different. CFD simulations partialy validated by measurement were used to evaluate the existing flow situation. Design changes were proposed and further investigated to improve the flows in the precipitator.
14
Konieczyński, Jan, Bogusław Komosiński, Ewelina Cieślik, Tomasz Konieczny, Barbara Mathews, Tomasz Rachwał, and Grzegorz Rzońca. "Research into properties of dust from domestic central heating boiler fired with coal and solid biofuels." Archives of Environmental Protection 43, no. 2 (June 27, 2017): 20–27. http://dx.doi.org/10.1515/aep-2017-0019.
Full textAbstract:
Abstract The aim of this research was to assess the content and composition of the pollutants emitted by domestic central heating boilers equipped with an automatic underfeed fuel delivery system for the combustion chamber. The comparative research was conducted. It concerned fuel properties, flue gas parameters, contents of dust (fl y ash) and gaseous substances polluting the air in the flue gases emitted from a domestic CH boiler burning bituminous coal, pellets from coniferous wood, cereal straw, miscanthus, and sunflower husks, coniferous tree bark, and oats and barley grain. The emission factors for dust and gaseous air pollutants were established as they are helpful to assess the contribution of such boilers in the atmospheric air pollution. When assessing the researched boiler, it was found out that despite the development in design and construction, flue gases contained fly ash with a significant EC content, which affected the air quality.
15
Soemarwoto, Bambang I., Okko J. Boelens, and Toni Kanakis. "Aerodynamic design of gas turbine engine intake duct." Aircraft Engineering and Aerospace Technology 88, no. 5 (September 5, 2016): 605–12. http://dx.doi.org/10.1108/aeat-02-2015-0063.
Full textAbstract:
Purpose The purpose of this paper is to provide a design solution of an engine intake duct suitable for delivering air to the compressor of a gas turbine engine of a general aviation turboprop aircraft, where the initial duct shape suffers a problem of flow distortion due to flow separation at the compressor inlet. Design/methodology/approach Aerodynamic design uses a three-dimensional inverse-by-optimization approach where the deviation from a desirable target pressure distribution is minimized by means of the adjoint method. Findings By virtue of a minimization algorithm, the specified target pressure distribution does not necessarily have to be fully realizable to drive the initial pressure distribution towards one with a favourable pressure gradient. The resulting optimized engine intake duct features a deceleration region, in a diverging channel, followed by an acceleration region, in a contracting channel, inhibiting flow separation on the compressor inlet plane. Practical implications The flow separation at the compressor inlet has been eliminated allowing proper installation of the engine and flight testing of the aircraft. Originality/value Placement and shaping of the intake duct of a turboshaft and turboprop gas turbine engine is a common industrial problem which can be challenging when the available space is limited. The inverse-by-optimization approach based on a reduced flow model, i.e. inviscid flow based on the Euler equations, and a specification of a simple target pressure distribution constitutes an efficient method to overcome the challenge.
16
Benedetto, Almerinda Di, Paola Russo, and Ernesto Salzano. "The design of duct venting of gas explosions." Process Safety Progress 27, no. 2 (2008): 164–72. http://dx.doi.org/10.1002/prs.10239.
Full text
17
Grigoriev, A. V., O. A. Rudakov, and A. V. Solovieva. "Gas dynamic calculation of detonation in variable cross-section ducts." VESTNIK of Samara University. Aerospace and Mechanical Engineering 18, no. 1 (April 16, 2019): 42–54. http://dx.doi.org/10.18287/2541-7533-2019-18-1-42-54.
Full textAbstract:
Formulas of gas dynamic calculation of detonation parameters in variable cross-section ducts are presented and a design detonation diagram is given. The diagram shows the detonation characteristics of super-compressed detonation and under-compressed detonation as the function of shock wave specific speed depending on the intensity of temperature of the ideal gas in a subsonic one-dimensional flow behind the shock wave propagating in a chemically active air-fuel mixture and on the ratio of geometrical expansion (convergence) of the duct. The propagation of a stationary shock-wave the static pressure of which in the output cross-section of the expanded duct is equal to atmospheric pressure is referred to as design detonation. This means that all the energy of the shock wave at the output of the duct can be converted into polytropic work function of gas expansion in a detonation engine. Otherwise, if the flow takes place in the mode of overexpansion due to the separation of the compressive shock wave inside the duct or in the case of insufficient expansion part of the shock wave energy will be lost. The total impulse equation for a geometrically expanding duct is solved by replacing the integral describing the thrust force with the average integral value of the curve of the static pressure acting on the side wall of the expanding duct. The frictional force is neglected due to its insignificant value. It is shown that the presence of an insufficiently compressed shock wave is not possible as the shock wave moving at the supersonic speed in the convergent duct will be decelerated to the sonic speed. To stabilize it additional heat should be supplied to transform the convergent duct behind the compressive shock wave into a semi-permanent cross-section duct wherein thermal crisis stabilizing the shock wave can be achieved. The minimum value of the detonation pipe diameter of 50 mm is substantiated. Below that value sharp reduction of combustion efficiency takes place. The results of the work can be used for the computation of detonation engine thermodynamic cycle parameters.
18
Tu, J. Y., C. A. J. Fletcher, M. Behnia, J. A. Reizes, D. Owens, and P. Jones. "Prediction of Flow and Erosion in Power Utility Boilers and Comparison With Measurement." Journal of Engineering for Gas Turbines and Power 119, no. 3 (July 1, 1997): 709–16. http://dx.doi.org/10.1115/1.2817046.
Full textAbstract:
Multidimensional simulations of both flue gas and fly ash (solid particle) flows with application to erosion prediction in the economisers of coal-fired power utility boilers are reported. A computer code specifically designed for power utility boilers, DS4PUB (Design Software for Power Utility Boilers), was used for the calculations. The major area of erosion often occurs at the economizer of the boiler and depends on the particulate velocity and concentration so that computational results include the economizer inlet distribution of the mean flue gas and particulate velocities, and fly ash concentration. The computer code was validated by comparisons with previously available experimental data and recently performed measurements for flue gas flow velocity, dust burden, and erosion rates at the inlet of economizers in large operating power stations. The results of the multidimensional simulations agreed reasonably well with the experimental measurements. An important finding of this study is that the transverse location of maximum erosion in the economizer tube bank strongly depends on the upstream geometric design of the boiler. For boilers with a shorter turning flow path, the maximum erosion is found to be close to the rear wall of the economizer because both the maximum particulate velocity and concentration occur in this region. For configurations with a long flow path, which includes a splitter plate, the maximum erosion region was found to be closer to the front wall of the economizer, mainly due to the high flow velocity in this region. A relatively high erosion area close to the side and rear wall was also found because of the high concentration of large fly ash particles in this area. Interesting feature of fly ash flow in multidimensional complex boiler geometries such as concentration distributions for different fly ash particle sizes are also discussed.
19
Karaman, Mehmet, Ibrahim Özkol, and Güven Kömürgöz. "Heat Transfer Enhancement in Turbine Blade Internal Cooling Ducts." Advanced Materials Research 1016 (August 2014): 743–47. http://dx.doi.org/10.4028/www.scientific.net/amr.1016.743.
Full textAbstract:
Gas turbine is a type of rotary engine that consists of compressor, combustion chamber, and turbine sections. This type of engine works in the Brayton Cycle principle that is compression of atmospheric flow, combustion of air-fuel mixture and expanding high temperature combustion flow to generate power output from turbine. The aim of this study is to determine the duct geometry and flow conditions of the gas turbine blades having the internal cooling ducts that acquire highest heat transfer on turbine blades. For different design of internal duct geometries and flow conditions, Fluent solver is used and solutions are validated with Han’s experimental results.
20
Zheng, Le Yu, Ye Geng, Guo Dong Yuan, Bei Bei Yan, Zheng Wei Long, Feng Sun, and Xiao Ke Guo. "Numerical Simulation on Coal-Fired Power Plant Flue Pipe with Different Kinds of Inner Supports." Advanced Materials Research 889-890 (February 2014): 241–45. http://dx.doi.org/10.4028/www.scientific.net/amr.889-890.241.
Full textAbstract:
Large rectangular gas ducts installed in power plants usually need inner supports to ensure their stability. Generally two schemes are used for setting inner supports. One is National Standard Specification (NSS) and the other is an American Combustion Engineering company design criterion (CE). The design level of inner supports in flue pipe has a great effect on flow distribution. In this paper, three kinds of inner supports which are common in power plants are simulated by using computational fluid dynamics (CFD). Through a comprehensive analysis of their flow fields and pressure, it can be concluded that NSS inner supports which are thinner, vertical to each other and have more rows is the best design scheme among these three kinds of inner supports.
21
Wang, He Cen, De Hou Jiang, and Qin Wang. "Study on Application and Issues of Bag Dedusters in Coal-Fired Power Plants." Advanced Materials Research 201-203 (February 2011): 2634–44. http://dx.doi.org/10.4028/www.scientific.net/amr.201-203.2634.
Full textAbstract:
To meet the standard requirements of dust emission for boiler and ensure the safety and normal operation of desulfurization equipment, bag dust filtering technologies have been used widely to deal with flue gas. Because of design defects and different running conditions, abnormal breakage may appear in the key parts of the bags, particularly some issues such as oxidation and acidic corrosion of the bags may happen in short-term application of electrostatic-bag precipitators. This paper elaborates the status of bag filters in coal-fired power plants, discusses some issues of bag filtering technology in design, manufacture and operation, and especially analyses the special problems of composite electrostatic-bag precipitators. Solutions are presented for extending the life of filtering bags.
22
Yurko, Volodymyr, Anton Ganzha, Oleksandra Tarasenko, and Larysa Tiutiunyk. "Improvement of methods for calculating thermal characteristics of loop air heaters." Eastern-European Journal of Enterprise Technologies 1, no. 8 (109) (February 26, 2021): 36–43. http://dx.doi.org/10.15587/1729-4061.2021.225330.
Full textAbstract:
Utilization of heat from gases leaving the waelz process is a promising way to increase its energy efficiency and environmental safety. Taking into account the gas dustiness, the most rational is the use of a loop air heater, which is a multi-pass and multi-section heat exchanger with a complex mixed scheme of coolant movement. In modern conditions, when the methods and means of calculation of such devices are simplified, the task of obtaining improved methods and means of calculation, determining the efficiency and reliability of their work is relevant. Two mathematical models of the process of heat transfer and hydroaerodynamics in a multi-pass tubular air heater with a cross-circuit of coolants are used. The developed models for the loop air heater are based on the main methods of thermal calculation: a simpler method of correction factor to the average logarithmic temperature pressure and a discrete P-NTU method, which allows obtaining local thermal characteristics of the surface. Diagrams of distribution of heat transfer coefficients, heat transfer, local temperatures of flue gases, air and pipe walls are constructed. The influence of dust and dust particle size on heat transfer is determined. When the flue gas dust is 50 g/Nm3 and with a dust particle size of 1 μm, the heat transfer coefficient increases by 12 %. The application of the air heater design with different schemes of coolant movement is substantiated. The developed universal methods allow determining the thermal productivity of heat exchangers and obtaining the distribution of local temperature characteristics on the heating surface. It is also possible to identify places of possible overheating of the heat exchange surface and the course of corrosion processes, taking into account the design of recuperators, operating conditions, operating modes and different schemes of coolant movement
23
Im, Ju Hyun, Sun Je Kim, Myung Ho Kim, You Il Kim, and Yeong Ryeon Kim. "Design Study of a Simulation Duct for Gas Turbine Engine Operations." Journal of the Korean Society of Propulsion Engineers 23, no. 1 (February 1, 2019): 124–31. http://dx.doi.org/10.6108/kspe.2019.23.1.124.
Full text
24
Huang, Z. Y., Z. M. Zhang, M. S. Yao, and S. Y. He. "Design and experiment of hot gas duct for the HTR-10." Nuclear Engineering and Design 218, no. 1-3 (October 2002): 137–45. http://dx.doi.org/10.1016/s0029-5493(02)00206-6.
Full text
25
Willett, Fred T., and Arthur E. Bergles. "Heat Transfer in Rotating Narrow Rectangular Ducts With Heated Sides Parallel to the r-z Plane." Journal of Heat Transfer 124, no. 1 (June 12, 2001): 1–7. http://dx.doi.org/10.1115/1.1418370.
Full textAbstract:
In gas turbine blade design, a variety of channel shapes and orientations are used in the cooling circuit. Most of the rotating channel heat transfer research to date has considered channels of square or round cross-sections. This research characterizes the effect of rotation on fully developed turbulent convective heat transfer in ducts of narrow cross-section (height-to-width aspect ratio of 1:10). Experiments were conducted using ducts of narrow cross-section, oriented such that the long sides of the duct cross-section are perpendicular to the direction of blade tangential velocity (parallel to the r-z plane). In the experiment, a high-molecular-weight gas (Refrigerant-134A) at ambient pressure and temperature conditions was used to simulate coolant-to-wall density ratios that match engine conditions. Thin foil heaters were used to produce a uniform heat flux at the long sides of the duct; the narrow sides were unheated. Duct Reynolds numbers were varied up to 31,000; rotation numbers were varied up to 0.11. The test results show the effect of rotation and aspect ratio on duct leading and trailing side heat transfer. The results provide insight into the effect of rotation (Coriolis) in the absence of buoyancy effects. Comparisons with previously reported results are presented to show the effect of cross-section shape on rotating channel heat transfer.
26
Корнев, В. А., Г. И. Абдуллина, Л. Г. Аскинази, А. А. Белокуров, Н. А. Жубр, С. В. Лебедев, Д. В. Разуменко, and А. С. Тукачинский. "Оптимизация потерь мощности атомарного пучка при его транспортировке в плазму токамака ТУМАН-3М." Письма в журнал технической физики 47, no. 6 (2021): 3. http://dx.doi.org/10.21883/pjtf.2021.06.50748.18629.
Full textAbstract:
Paper reports a physical model of the beam transportation through the duct with realistic geometry. The beam losses are explained by interaction of the energetic particles of the beam with the duct walls resulting in strong influx of neutral gas, which interact with beam particles and cause their reionizaton. Using the model new design of the beam duct was developed. Ratio of the neutron fluxes values obtained under similar experimental conditions with the new transition duct and the old one fitted well with the model predictions.
27
Song, Kee Nam, Hyeong Yeon Lee, Yong Wan Kim, and Soo Bum Lee. "Preliminary Design Analysis of a Hot Gas Duct for the NHDD Program at Korea." Advanced Materials Research 33-37 (March 2008): 1227–32. http://dx.doi.org/10.4028/www.scientific.net/amr.33-37.1227.
Full textAbstract:
Korea Atomic Energy Research Institute (KAERI) is in the process of carrying out a Nuclear Hydrogen Development and Demonstration (NHDD) Program by considering the indirect cycle gas cooled reactors that produce heat at temperatures in the order of 950°C. A coaxial doubletube hot gas duct (HGD) is a key component connecting the reactor pressure vessel and the intermediate heat exchanger (IHX) for the NHDD program. Recently, a preliminary design evaluation for the hot gas duct of the NHDD program was carried out. These preliminary design activities include a preliminary decision on the geometric dimensions, a preliminary strength evaluation, an appropriate material selection, and identifying the design code for the HGD. In this study, a preliminary strength evaluation for the HGD of the NHDD program has been undertaken based on the HTR-10 design concepts. Also, a preliminary evaluation of the creep-fatigue damage for a high temperature HGD structure has been carried out according to the draft code case for Alloy 617. Preliminary strength evaluation results for the HGD showed that the geometric dimensions of the proposed HGD would be acceptable for the design requirements.
28
Vasilyev, Andrey. "RESEARCH OF LOW FREQUENCY GAS PRESSURE OSCILLATIONS IN DUST SYSTEMS OF POWER PLANTS USING PROGRAM PROVISION." Akustika 34 (November 1, 2019): 123–26. http://dx.doi.org/10.36336/akustika201934123.
Full textAbstract:
Vibration and related with it mechanical noise of power plants and joining mechanical systems are the factors negatively impacted not only to the health of workers, but also to the durability, reliability, productivity and other parameters of power plants. Significant input into generation of vibration and of low frequency noise are bringing pressure oscillations in ducts. Some approaches and results of program provision development for calculation of low frequency gas pressure oscillations in ducts of power plants are described. Results of program provision approbation are presented. Using of suggested program provision may be useful for calculation and design of duct systems of power plants and allows increase the efficiency of low frequency oscillations reduction in ducts of power plants systems and noise and vibration negative impact.
29
Hu, Tian, Yan Li, and Ren Yuan Tang. "Calculation of Fluid Flow Field and Thermal Field for Air-to-Air Cooled Medium Motor." Applied Mechanics and Materials 543-547 (March 2014): 362–65. http://dx.doi.org/10.4028/www.scientific.net/amm.543-547.362.
Full textAbstract:
For an air-to-air cooled medium motor, to ensure the cooling effect of the motor, the physical model of the motor cooling air inside the cooler was built. By the finite volume method according to the computational fluid mechanics (CFD) principle, the three-dimensional turbulent flow field in computational domain was simulated numerically using boundary conditions of the inlet and outlet obtained from engineering calculations. From the result, the thermal field of cooler was calculation. Finally, through the comparison, the cooler cooling the motor cooling effect sufficient play , the outer duct can effectively reduce the internal temperature of the cooling gas duct , the air duct outside the cooling gas declined about 35 °C after cooling the temperature of the air duct, the calculation method is feasible for the motor cooling system design overall foundation .
30
Xu, Qingzong, Pei Wang, Qiang Du, Jun Liu, and Guang Liu. "Effects of axial length and integrated design on the aggressive intermediate turbine duct." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 233, no. 4 (September 4, 2018): 443–56. http://dx.doi.org/10.1177/0957650918797450.
Full textAbstract:
With the increasing demand of high bypass ratio and thrust-to-weight ratio in civil aero-engine, the intermediate turbine duct between the high pressure and low pressure turbines of a modern gas turbine tends to shorter axial length, larger outlet-to-inlet area ratio and high pressure-to-low pressure radial offset. This paper experimentally and numerically investigated the three-dimensional flow characteristics of traditional (ITD1) and aggressive intermediate turbine duct (ITD2) at low Reynolds number. The baseline case of ITD1 is representative of a traditional intermediate turbine duct of aero-engine design with non-dimensional length of L/dR = 2.79 and middle angle of 20.12°. The detailed flow fields inside ITD1 and flow visualization were measured. Results showed the migration of boundary layer and a pair of counter-rotating vortexes were formed due to the radial migration of low momentum fluid. With the decreasing axial length of intermediate turbine duct, the radial and streamwise reverse pressure gradient in aggressive intermediate turbine duct (ITD2) were increased resulting in severe three-dimensional separation of boundary layer near casing surface and higher total pressure loss. The secondary flow and separation of boundary layer near the endwall were deeply analyzed to figure out the main source of high total pressure loss in the aggressive intermediate turbine duct (ITD2). Based on that, employing wide-chord guide vane to substitute “strut + guide vane”, this paper designed the super-aggressive intermediate turbine duct and realized the suppression of the three-dimensional separation and secondary flow.
31
Sui, Xiuming, Wei Zhao, Xiaolei Sun, Weiwei Luo, and Qingjun Zhao. "Aerodynamic performance analysis and optimization of a turbine duct with low degree of partial admission." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 232, no. 5 (February 19, 2017): 988–1001. http://dx.doi.org/10.1177/0954410017691068.
Full textAbstract:
A partial admission turbine duct with outlet-to-inlet area ratio greater than unity can increase the admission degree of the downstream turbine stage and, thus improve the performance of a multistage turbine with a low partial admission degree. However, the upstream flow structures of ducts, such as secondary flow, especially the circumferential nonuniformities originating from the effect of the partial admission, make the flow in ducts complex. The complexity of the flow has a negative impact on the performance of ducts. In the present investigation, numerical study of the flow behavior within ducts is done to evaluate the effect of the partial admission on the performance of the ducts. The study is carried out with regard to two cases, i.e. which are with the same duct geometry but are at different working conditions to highlight the impact of partial admission on the performance of ducts. Case 1 is used as baseline. It is designed based on circumferential mass-averaged flow conditions at ducts inlet. It causes the circumferential nonuniformities originating from the partial admission to have no impact on the performance of case 1. Case 2, which considers partial admission, is compared with case 1 to know the impact of the partial admission on the performance of ducts, and to give guidelines to design a duct for the partial admission turbines. Since the duct inlet conditions is a result of the interaction between partial admission turbine and duct, a straightforward way to consider the effect of the partial admission is to simulate the flows in ducts and upstream turbines contemporaneously. Comparative results indicate that the mixing of main flow in the admitted channel and the windage fluid from the unadmitted channel occurs at the duct inlet close to the duct circumferential wall. The adverse pressure gradient of case 2 in that region becomes larger than that of case 1. As a result, the flow separates at that region deteriorating the performance of ducts. Based on the simulation results of the previous cases, case 2’s circumferential wall surface, which is along the gas swirling direction is shrunk to accelerate the flow and, thereby, overcome the adverse pressure gradient imposed by the effect of the partial admission. The results show that the separation is restrained and the decrease in total pressure loss is 52.9%.
32
Shuvaev, Nikolay, Aleksandr Siner, and Ruslan Kolegov. "DEVELOPMENT OF THE NUMERICAL METHODOLOGY FOR THE ESTIMATION OF RESONANT PROCESSES AT GASTURBINE ENGINE FLOW DUCT." Perm National Research Polytechnic University Aerospace Engineering Bulletin, no. 62 (2020): 12–19. http://dx.doi.org/10.15593/2224-9982/2020.62.02.
Full textAbstract:
Ensuring safety of flights is the most important task that is being solved in the process of designing an aircraft engine and aircraft. The most complex are the physical processes occurring inside the aircraft engine, especially in its gas generator: combustion chamber, high-pressure compressor and high-pressure turbine. The unsteady flow of gas in the flow duct of the aircraft engine is very complex, it is difficult to model, because the flow is characterized by a wide range of time and space scales. Unsteady flow in a high-pressure compressor can cause surge and breakdown of the compressor and the entire engine as a whole. Along with the detachment flows causing the surge, in the flow duct there can be resonant phenomena associated with the propagation of powerful sound waves along the flow duct of the engine, which, when a direct and reflected wave is imposed, create a very powerful standing wave that affects the structure. With a certain combination of conditions, the coincidence of the natural frequencies of the oscillations of the air volume and the solid body, such resonant processes in the flow duct of the gas turbine engine can lead to serious breakdowns, such as breakage of rotor blades and guide vanes, destruction of the aeroengine framework and other. The main difficulty is that it is problematic to identify such processes at the design and debugging stage, since there are no suitable mathematical models, and for experimental verification it is required to withstand the specific operating conditions of the node that are not known in advance. This work is devoted to the creation of a calculation technique that will allow in the future to diagnose resonance phenomena at the design stage and thereby significantly reduce the costs for the design, testing and manufacture of an aircraft engine. The proposed technique is based on the nonstationary Navier-Stokes equations for a compressible gas.
33
Xu, Geng, Ren Jun Yan, Chang Lian She, Lin Zhi Xu, Lin Xu, and Fen Li. "Research of Flow Mechanism and Numerical Simulation on the Post-Prestressed Duct Grouting." Applied Mechanics and Materials 405-408 (September 2013): 1567–73. http://dx.doi.org/10.4028/www.scientific.net/amm.405-408.1567.
Full textAbstract:
Post-prestressed duct grouting is a complex construction process and it is affected by many factors. Since there are no clear cognitive relations to the influencing factors of the grouting quality, it is hard to make the best control program during the construction. By the theoretical applicability and parameters analysis through the grouting process, this article used the numerical simulation method to analyze the grouting process and obtained the correspondence between the initial velocity, grouting pressure and grouting quality. To the height difference and bending in the duct, the relationship between volume and forming quality were analyzed, the results has reference value to the design of duct gas vent.
34
Balicki, Włodzimierz, Paweł Głowacki, Stefan Szczecinski, Ryszard Chachurski, and Jerzy Szczeciński. "Effect of the Atmosphere on the Performances of Aviation Turbine Engines." Acta Mechanica et Automatica 8, no. 2 (August 15, 2014): 70–73. http://dx.doi.org/10.2478/ama-2014-0012.
Full textAbstract:
Abstract The paper presents how the parameters defining the state of the atmosphere: pressure, temperature, humidity, are affecting performance of the aircraft turbine engines and their durability. Also negative impact of dust pollution level is considered as an important source of engine deterioration. Article highlights limitation of the aircraft takeoff weight (TOW) and requirements for length of the runways depending on weather condition changes. These problems stem from the growing “demand” of gas turbine engines for an air. The highest thrust engines have air mass flow more than 1000 kg/s. Engine inlet ice formation is presented as a result of weather conditions and inlet duct design features.
35
Glebov, G. A., and S. A. Vysotskaya. "On the question of solid-propellant rocket engine design preventing unstable operation in the combustion chamber." Journal of «Almaz – Antey» Air and Space Defence Corporation, no. 4 (December 30, 2017): 63–72. http://dx.doi.org/10.38013/2542-0542-2017-4-63-72.
Full textAbstract:
The paper presents results of a numerical investigation concerning the effect that the flow duct shape and combustion rate equation have on the gas dynamic vortex flow pattern and self-excited pressure oscillations in the combustion chamber of a solid-propellant rocket engine. We provide guidelines on upgrading solid-propellant rocket engines in order to decrease the magnitude of pressure pulses in the case of pulsating combustion.
36
Ng’aru, Joseph Mwangi, Sunho Park, and Beom-soo Hyun. "Computational Analysis of KCS Model with an Equalizing Duct." Journal of Ocean Engineering and Technology 35, no. 4 (August 31, 2021): 247–56. http://dx.doi.org/10.26748/ksoe.2021.015.
Full textAbstract:
In order to minimize carbon emissions and greenhouse gas, the Energy Efficiency Design Index (EEDI) has become a major factor to be considered in recent years in a ship’s design and operation phases. Energy-Saving Devices (ESDs) improve the EEDI of a vessel and make them environmentally friendly. In this research, the performance of an equalizing duct-type ESD installed upstream of a Korea Research Institute of Ships & Ocean Engineering (KRISO) Container Ship (KCS) model’s propeller was investigated by computational fluid dynamics (CFD). Open-source CFD libraries, OpenFOAM, were used for computational analysis of the KCS with and without the ESD to verify the performance improvement. The flow field near the stern region and propulsive coefficients were considered for comparison. The results showed a considerable improvement when an ESD was used on the model. Using different sizes of the duct, the performance of the ESD was also compared. It was observed that with an increased duct size, the propulsive performance was improved.
37
Liu, Juan, Yan Long Jiang, Hong Shi, Zhi Li Liu, Chao Liu, and Yan Ping Du. "Modal Analysis of the High Temperature and Pneumatic Duct System of the Aircraft." Advanced Materials Research 663 (February 2013): 552–59. http://dx.doi.org/10.4028/www.scientific.net/amr.663.552.
Full textAbstract:
Based on the analysis of the loads, constraints and its mechanisms applying to the duct system, a finite element model of the anti-ice system is developed and the Lanczos algorithm is used for modal analysis. Then, the first eight natural frequencies and vibration modes are obtained. The thermodynamic parameters of the gas and the kinetic parameters of the ball joint which have influence on the modal analysis are considered. The results show that the first eight order natural frequencies of the anti-ice Part1 are low and concentrated, and decrease with temperature of the gas while increase with pressure of the gas. Meanwhile, the natural frequencies increase with the stiffness and starting torque of the ball joint. This work could be helpful for reliability design of civil-aircraft ducting system.
38
Zamalieva, A. T., and M. G. Ziganshin. "Improving the reliability, as well as energy and environmental efficiency of gas cleaning systems at TPP." Safety and Reliability of Power Industry 11, no. 4 (January 21, 2019): 288–93. http://dx.doi.org/10.24223/1999-5555-2018-11-4-288-293.
Full textAbstract:
Energy is the basic sector of the economy and the largest consumer of primary energy resources of any country, which is why the development of world energy is accompanied by global pressure on the environment. The issues are considered of reducing the atmospheric impact of emissions of thermal power plants, improving the reliability and working life of their units, systems, and plants as a whole. The principles are presented of development and improvement of technologies for processing industrial emissions of thermal power plants, the neutralization of which is currently relevant on a regional and global scale. Analysis is carried out of existing methods of cyclone and filtration treatment. An improved design of a cyclone filter is proposed, which allows to increase the reliability of gas turbine and steam-gas units of TPP, while ensuring the efficiency of separation of the suspended part of the flow at the gas treatment point (GTP) of TPP. Similar devices can also be used to increase the degree of cleaning atmospheric emissions released by the TPP coal dust preparation and flue gas systems at coal generation from fi ne particles of PM10 and PM2,5 classes (coal dust and ash), owing to reduction of the size of caught particles from average values for cyclones and wet scrubbers of the order of 5–10 μm to 0.5 μm. The design of the cyclone filter is improved as a result of research of cyclone filtration by methods of Computational Fluid Dynamics (CFD). A system of Reynolds-averaged equations of a single-phase Navier-Stokes flow is used for mathematical modeling of motion in the cyclone filter. To determine the efficiency of separation of the suspended part of the flow in the cyclone filter, the Rercomplex is used obtained by reducing a set comprising the Navier-Stokes equations and the equation of particle motion based on Newton's law to a dimensionless form. Numerical characteristics of the suspension sedimentation from a multiphase flow in a cyclone separator of specified dimensions are found by means of the Rercomplex. The results of bench tests of the proposed design of the cyclone filter are given.
39
Tafti, Danesh, Cody Dowd, and Xiaoming Tan. "High Reynold Number LES of a Rotating Two-Pass Ribbed Duct." Aerospace 5, no. 4 (November 23, 2018): 124. http://dx.doi.org/10.3390/aerospace5040124.
Full textAbstract:
Cooling of gas turbine blades is critical to long term durability. Accurate prediction of blade metal temperature is a key component in the design of the cooling system. In this design space, spatial distribution of heat transfer coefficients plays a significant role. Large-Eddy Simulation (LES) has been shown to be a robust method for predicting heat transfer. Because of the high computational cost of LES as Reynolds number (Re) increases, most investigations have been performed at low Re of O(104). In this paper, a two-pass duct with a 180° turn is simulated at Re = 100,000 for a stationary and a rotating duct at Ro = 0.2 and Bo = 0.5. The predicted mean and turbulent statistics compare well with experiments in the highly turbulent flow. Rotation-induced secondary flows have a large effect on heat transfer in the first pass. In the second pass, high turbulence intensities exiting the bend dominate heat transfer. Turbulent intensities are highest with the inclusion of centrifugal buoyancy and increase heat transfer. Centrifugal buoyancy increases the duct averaged heat transfer by 10% over a stationary duct while also reducing friction by 10% due to centrifugal pumping.
40
Harte, Reinhard, Martin Graffmann, and Wilfried B. Krätzig. "Optimization of Solar Updraft Chimneys by Nonlinear Response Analysis." Applied Mechanics and Materials 283 (January 2013): 25–34. http://dx.doi.org/10.4028/www.scientific.net/amm.283.25.
Full textAbstract:
Solar updraft chimneys (SUCs) form as engines of solar updraft power plants tower-like shell structures of extreme height with rather thin shell walls, similar to high chimneys comprising multiple flue gas ducts. The height of pre-designed SUCs presently reaches up to 1000 m. Thus they are exposed chiefly to extreme wind-loads and thermal actions from the internal flow of warm air. As first design attempt, the structural analysis of solar chimneys generally is carried out by linear elastic models. For optimization, the typical shell-like wind stresses have to be constraint towards a more beam-like response behavior, approaching as far as possible linear stresses over the entire chimney circumference. This requires rather strong ring stiffeners, either as spoke-wheels in the designs of sbp (Schlaich Bergermann and Partners) or as external stiffeners in the designs of K&P (Krätzig and Partners). Both alternatives require considerable construction efforts leading to high investment costs. There exists an interesting simplification of this stiffening, namely applying to the SUC shell relatively soft external rings, and admitting large-widths cracking in the limit state of failure. This cracking constraints and equalizes the meridional stresses over the chimney’s cross-section, saving large amounts of reinforcement steel in the SUC. The design requires materially nonlinear analyses to verify the internal forces under crack-formations. The manuscript will derive this concept and demonstrate the crack analysis by example of a 750 m high solar chimney.
41
Bhargava, R. K., C. B. Meher-Homji, M. A. Chaker, M. Bianchi, F. Melino, A. Peretto, and S. Ingistov. "Gas Turbine Fogging Technology: A State-of-the-Art Review—Part III: Practical Considerations and Operational Experience." Journal of Engineering for Gas Turbines and Power 129, no. 2 (February 1, 2006): 461–72. http://dx.doi.org/10.1115/1.2364005.
Full textAbstract:
The strong influence of ambient temperature on the output and heat rate of a gas turbine has popularized the application of inlet fogging and overspray for power augmentation. In this paper we focus on practical considerations for the implementation of the fogging technology such as water quality requirements, foreign object damage, gas turbine inlet icing, intake duct design, changes in compressor performance characteristics, and blade coating distress problems. It also provides a checklist for users and project developers to facilitate the design and implementation of fogging systems. In addition, in this paper we cover operational experience and review the work pursued by gas turbine OEMs in the field of fogging technology. A list of unresolved issues and ongoing research related to the fogging technology is also provided.
42
Rtischeva, A. S. "Gas Dynamic Design and Numerical Study of Supersonic Circuit of Wind Tunnel." Herald of the Bauman Moscow State Technical University. Series Mechanical Engineering, no. 1 (136) (March 2021): 68–84. http://dx.doi.org/10.18698/0236-3941-2021-1-68-84.
Full textAbstract:
For an advanced trisonic wind tunnel of a straight-flow type with a test section size of 1.2 × 1.2, intended for ground tests of rocket-space and aviation aircraft models, we implemented a gas-dynamic design of the circuit and did numerical simulation of the flow for the main supersonic regimes (M = 2, M = 4). The gas-dynamic design of the wind tunnel circuit was carried out on the basis of techniques developed at TsAGI and operating experience of existing facilities. The study considers both traditional configurations of the duct with the bending of the walls of all elements, i.e., nozzle, test section and diffuser in the XY plane, and alternative design developments with the bending of the diffuser walls in the XZ plane. When carrying out numerical studies in all areas of the wind tunnel, the ANSYS Fluent software package was used to solve the Navier --- Stokes equations for viscous and heat-conducting air using the turbulence model, i.e., Spalart --- Allmaras, SST. The paper investigates the effect of the wall opening angle, compensating the increasing thickness of boundary-layer longwise displacement, on the flow characteristics; shows the possibilities of obtaining a sufficiently uniform flow with the Mach number accuracy ΔM = ± 0.005 in the area of the model, and analyzes the influence of geometric parameters and boundary conditions on the efficiency of the supersonic diffuser
43
Hussein, Norelyza, Mohd Rashid Mohd Yusof, Nur Hasyimah Hashim, Eeydzah Aminudin, and Che Hafizah Che Hassan. "Configuration of a newly optimized multi-cyclones unit as a fine particulate emission separator in air pollution control." Malaysian Journal of Fundamental and Applied Sciences 16, no. 1 (February 2, 2020): 90–95. http://dx.doi.org/10.11113/mjfas.v16n1.1644.
Full textAbstract:
Multi-cyclones separator, which consists of many miniature cyclones, works in the same principle as single cyclone in separation of particulate matter from flue gas. However, multi-cyclone is able to attain higher collection efficiency and concurrently avoid rapid increasing of pressure drop due to the usage of small diameter cyclone. The studies on multi-cyclones are very limited and lacking especially on its design configurations due to its confidentiality and commercial reason. Thus, a configuration of a newly optimized multi-cyclone unit named as MR-deDuster is discussed and assessed in this study. Six dimensions considered in the study include diameter of cyclone (D), diameter of vortex finder (De), length of cyclone body (Lb), length of cyclone cone (Lc), length of vortex finder (S), and diameter of dust outlet (Dd). The theoretical background of the unit was developed based on the modifications of established design equations available in literatures. The selection of the new dimension and the actual size of the unit were based on two main criteria (the performance of the unit based on its cut-diameter and the ratio of axial dimensions). The predicted cut-diameter and pressure drop of the selected dimension was 1.7 µm and 86 mm of water, respectively. Meanwhile, the optimum axial ratios of the final design were Lb/D = 1.6, S/D = 1, and Lb-S/D = 0.7, with respect to the diameter of the cyclone.
44
Tafti, Danesh K., Long He, and K. Nagendra. "Large eddy simulation for predicting turbulent heat transfer in gas turbines." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 372, no. 2022 (August 13, 2014): 20130322. http://dx.doi.org/10.1098/rsta.2013.0322.
Full textAbstract:
Blade cooling technology will play a critical role in the next generation of propulsion and power generation gas turbines. Accurate prediction of blade metal temperature can avoid the use of excessive compressed bypass air and allow higher turbine inlet temperature, increasing fuel efficiency and decreasing emissions. Large eddy simulation (LES) has been established to predict heat transfer coefficients with good accuracy under various non-canonical flows, but is still limited to relatively simple geometries and low Reynolds numbers. It is envisioned that the projected increase in computational power combined with a drop in price-to-performance ratio will make system-level simulations using LES in complex blade geometries at engine conditions accessible to the design process in the coming one to two decades. In making this possible, two key challenges are addressed in this paper: working with complex intricate blade geometries and simulating high-Reynolds-number ( Re ) flows. It is proposed to use the immersed boundary method (IBM) combined with LES wall functions. A ribbed duct at Re =20 000 is simulated using the IBM, and a two-pass ribbed duct is simulated at Re =100 000 with and without rotation (rotation number Ro =0.2) using LES with wall functions. The results validate that the IBM is a viable alternative to body-conforming grids and that LES with wall functions reproduces experimental results at a much lower computational cost.
45
Chaker, Mustapha, Cyrus B. Meher-Homji, and Thomas Mee. "Inlet Fogging of Gas Turbine Engines—Part II: Fog Droplet Sizing Analysis, Nozzle Types, Measurement, and Testing." Journal of Engineering for Gas Turbines and Power 126, no. 3 (July 1, 2004): 559–70. http://dx.doi.org/10.1115/1.1712982.
Full textAbstract:
The inlet fogging of gas turbine engines for power augmentation has seen increasing application over the past decade yet not a single technical paper treating the physics and engineering of the fogging process, droplet size measurement, droplet kinetics, or the duct behavior of droplets, from a gas turbine perspective, is available. This paper provides the results of extensive experimental and theoretical studies conducted over several years, coupled with practical aspects learned in the implementation of nearly 500 inlet fogging systems on gas turbines ranging in power from 5 to 250 MW. Part II of the paper treats the practical aspects of fog nozzle droplet sizing, measurement and testing presenting the information from a gas turbine fogging perspective. This paper describes the different measurement techniques available, covers design aspects of nozzles, provides experimental data on different nozzles, and provides recommendations for a standardized nozzle testing method for gas turbine inlet air fogging.
46
Gabrielsson, R., and G. Holmqvist. "Progress on the European Gas Turbine Program “AGATA”." Journal of Engineering for Gas Turbines and Power 120, no. 1 (January 1, 1998): 179–85. http://dx.doi.org/10.1115/1.2818072.
Full textAbstract:
The four-year European Gas Turbine Program “AGATA” was started in January 1993 with the objective of developing three critical components aimed at a 60 kW turbogenerator in an hybrid electric vehicle: a catalytic combustor, a radial turbine wheel and a static heat exchanger. The AGATA partners represent car manufacturers as well as companies and research institutes in the turbine, catalyst, and ceramic material fields in both France and Sweden. This paper outlines the main results of the AGATA project for the first three-year period. Experimental verification of the components started during the third year of the program. A high-pressure/temperature test rig for the combustor and the heat exchanger tests has been built and is now being commissioned. A high-temperature turbine spin rig will be ready late 1995. The turbine wheel design is completed and ceramic Si3N4 spin disks have been manufactured by injection molding and Hot Isostatic Pressing (HIP). A straight blade design has been selected and FEM calculations have indicated that stress levels that occur during a cold start are below 300 MPa. The catalytic combustor final design for full-scale testing has been defined. Due to the high operating temperature, 1350°C, catalyst pilot tests have included aging, activity, and strength tests. Based on these tests, substrate and active materials have been selected. Initial full-scale tests including LDV measurements in the premix duct will start late 1995. The heat exchanger design has also been defined. This is based on a high-efficiency plate recuperator design. One critical item is the ceramic thermoplastic extrusion manufacturing method for the extremely thin exchanger plates another is the bonding technique: ceramic to ceramic and ceramic to metal. Significant progress on these two items has been achieved. The manufacturing of quarter scale prototypes is now in process.
47
Castro-Duque, Yesid. "Optimization of the auxiliary ventilation system, based on experiments executed on a ventilation test bench for mines." DYNA 85, no. 207 (October 1, 2018): 208–13. http://dx.doi.org/10.15446/dyna.v85n207.64255.
Full textAbstract:
In this study, the simulation results of the parameters concerning mine ventilation on a test bench are presented. Said investigation incorporated the previous design and implementation of a monitoring system at the laboratory. This was in order to calculate the fan efficiency, based on electrical measurements, and fluid mechanics (Bernoulli theory), and whose results can be observed in real time on a computer or through other similar means. The designed system monitors parameters present in the atmosphere of the test bench’s duct, such as temperature, air pressure, methane gas concentration, and electrical variables like voltage and current. The aforementioned observation is done through a graphical interface designed with LabView 2011 software. Tests were performed varying the accessories. The reduction percentage, allows one to infer that the duct section was adequately designed.
48
Motyl, Przemysław, Danuta Król, Sławomir Poskrobko, and Marek Juszczak. "Numerical Modelling and Experimental Verification of the Low-Emission Biomass Combustion Process in a Domestic Boiler with Flue Gas Flow around the Combustion Chamber." Energies 13, no. 21 (November 9, 2020): 5837. http://dx.doi.org/10.3390/en13215837.
Full textAbstract:
The paper presents the results of numerical and experimental studies aimed at developing a new design of a 10 kW low-emission heating boiler fired with wood pellets. The boiler is to meet stringent requirements in terms of efficiency (η > 90%) and emissions per 10% O2: CO < 500 mg/Nm3, NOx ≤ 200 mg/Nm3, and dust ≤ 20 mg/Nm3; these emission restrictions are as prescribed in the applicable ECODESIGN Directive in the European Union countries. An innovative aspect of the boiler structure (not yet present in domestic boilers) is the circular flow of exhaust gases around the centrally placed combustion chamber. The use of such a solution ensures high-efficiency, low-emission combustion and meeting the requirements of ECODESIGN. The results of the numerical calculations were verified and confirmed experimentally, obtaining average emission values of the limited gases CO = 91 mg/Nm3, and NOx = 197 mg/Nm3. The temperature measured in the furnace is 450–500 °C and in the flue it was 157–197 °C. The determined boiler efficiency was 92%. Numerical calculations were made with the use of an advanced CFD (Computational Fluid Dynamics) workshop in the form of the Ansys programming and a computing environment with the dominant participation of the Fluent module. It was shown that the results obtained in both experiments are sufficiently convergent.
49
Junior, Ederaldo Godoy, José Rui Camargo, R. R. Santos, F. S. Rezende, A. Matotta Cassula, E. Marques Trindade, and José Roberto Bertoncello Danieletto. "Design of Biogas Pipeline Energy and Sanitation." Defect and Diffusion Forum 334-335 (February 2013): 264–73. http://dx.doi.org/10.4028/www.scientific.net/ddf.334-335.264.
Full textAbstract:
The study aimed at developing a methodology for the design and appropriate use of materials in the pipes for the collection and distribution of biogas. The increasing use of biogas for distributed generation in agro-industries, sewage treatment effluent and anaerobic landfills, and the absence of a specific standard for biogas pipes led to the development of the work. Because there is no standard for design and delivery of pipes for the collection and distribution of biogas, the main eco-efficient energy projects implemented in the country, units digester / bike generator 50 kVA to 200 kVA, were used duct poly vinyl chloride (PVC) that permeable to gases, suffers from contamination of biogas network to air, leaks, reduce the efficiency of filter retention of H2S and reduced life of the motor generator. The methane in biogas reacts with PVC and decomposition occurs, dissolution, swelling and loss of ductility of the tube. Since polyethylene is the material world-known and most suitable for transportation of gas fuels, and the fact that its raw material, ethylene in the chain of thermoplastics derived from petroleum, polyethylene comes before the PVC, which makes it more economical and safe.
50
Bernardo, S., A. P. Peres, and M. Mori. "COMPUTATIONAL STUDY OF CYCLONE FLOW FLUID DYNAMICS USING A DIFFERENT INLET SECTION ANGLE." Revista de Engenharia Térmica 4, no. 1 (June 30, 2005): 18. http://dx.doi.org/10.5380/reterm.v4i1.3543.
Full textAbstract:
The conventional design of the cyclone model has been used without significant
modifications for about a century. Recently, some studies were carried out to improve
equipment performance by evaluating the geometric influence of the tangential inlet section
and scroll inlet duct design. In this work, the influence of cyclone inlet section geometry
was studied using an angle of 45 degrees in relation to the cyclone body. The study was
conducted for the gas and gas-particle phases, based on an experimental study available in
the literature, where a conventional inlet section was used. Numerical experiments were
carried out with the CFX computational code. The fluid dynamics profiles and tangential
velocity component were evaluated for three inlet velocities (2.75, 7.75 and 15.2 m/s)
using the Reynolds Stress model. The results showed that this proposal is useful for
improving the cyclone performance.