共查询到17条相似文献,搜索用时 109 毫秒
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对间冷回热燃气轮机关键部件逆流板翅式换热器进行了动态性能的仿真研究。在考虑气体工质压缩性的基础上,根据换热器内部冷、热流体的压力、流量和温度的变化和冷热流道间隔板的热平衡,建立了逆流板翅式换热器的动态数学模型,在EASY5平台上搭建了逆流板翅式换热器的分布参数模型,并进行了动态的仿真试验计算。分析结果表明该逆流板翅式换热器模型较好地实现了对换热器内部流体流动和换热的模拟,可以作为部件模块,用来时间冷回热燃气轮机系统性能的仿真研究。 相似文献
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针对微型燃气轮机板翅式换热器结构参数与燃气轮机性能之间的耦合关系,建立了板翅式换热器多目标分析和优化模型。在此基础上,分析了2种设计条件(定燃烧室吸热量和定涡轮出功)下板翅式换热器关键参数对板翅式换热器和燃气轮机性能的影响。结果表明:影响燃烧室吸热量和涡轮出功的主要因素为换热器压损而并非换热器效能,2种设计条件下各参数的变化趋势一致(除燃烧室吸热量和涡轮出功外);在对翅片结构进行优化后,涡轮出功增大了6.8%,燃烧室吸热量减少了5.1%;相对于基本参数,优化后翅片厚度、翅片间距和波纹角减小,翅片高度增加,保证了板翅式换热器具有较小的压损;采用■耗散最小和采用熵产最小为优化目标时无明显区别。 相似文献
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在“高效紧凑不锈钢板翅式换热器”的研制过程中,我们曾取整个换热器的六分之一作为单元体,并对该单元体进行了变工况计算,取得了一些有参考价值的结果,使我们对板翅式换热器的变工况有了比较清楚的了解、并为板翅式换热器的安全运行提供了保障. 相似文献
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板翅式换热器是舰载燃气轮机首选换热器形式。针对平直型翅片的矩形通道的结构特点,建立了流动换热分析的耦合计算模型,采用计算流体动力学(CFD)方法对间冷器的通道流场进行了数值模拟。给出并分析了计算区域内多个截面的温度、压力、速度、局部传热系数等参数的分布图形和变化趋势,并考察了不同工况下间冷器的工作能力。 相似文献
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This paper has proposed an improved liquefied natural gas (LNG) fuelled combined cycle power plant with a waste heat recovery and utilization system. The proposed combined cycle, which provides power outputs and thermal energy, consists of the gas/steam combined cycle, the subsystem utilizing the latent heat of spent steam from the steam turbine to vaporize LNG, the subsystem that recovers both the sensible heat and the latent heat of water vapour in the exhaust gas from the heat recovery steam generator (HRSG) by installing a condensing heat exchanger, and the HRSG waste heat utilization subsystem. The conventional combined cycle and the proposed combined cycle are modelled, considering mass, energy and exergy balances for every component and both energy and exergy analyses are conducted. Parametric analyses are performed for the proposed combined cycle to evaluate the effects of several factors, such as the gas turbine inlet temperature (TIT), the condenser pressure, the pinch point temperature difference of the condensing heat exchanger and the fuel gas heating temperature on the performance of the proposed combined cycle through simulation calculations. The results show that the net electrical efficiency and the exergy efficiency of the proposed combined cycle can be increased by 1.6 and 2.84% than those of the conventional combined cycle, respectively. The heat recovery per kg of flue gas is equal to 86.27 kJ s?1. One MW of electric power for operating sea water pumps can be saved. The net electrical efficiency and the heat recovery ratio increase as the condenser pressure decreases. The higher heat recovery from the HRSG exit flue gas is achieved at higher gas TIT and at lower pinch point temperature of the condensing heat exchanger. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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用于太阳能空调的板型溴化锂吸收式制冷机 总被引:4,自引:1,他引:3
溴化锂吸收式制冷循环用于太阳能空调需要解决的主要问题是循环系统要适合集热器所能提供的热水温度范围,和提高溴冷机本身性能并降低其制造成本。板型(包括板壳式、板式、板翅式)换热器用于溴冷机具有效率高、结构紧凑、轻巧和成本较低等优点,已被本课题组研制的1台3kW板型单效溴冷机实验样机所证实。 相似文献
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Cycle simulation and analysis for two kinds of SOFC/GT hybrid systems were conducted with the help of the simulation tool: Aspen Custom Modeler. Two cycle schemes of recuperative heat exchanger (RHE) and exhaust gas recirculated (EGR) were described according to the air reheating method. The system performance with operating pressure, turbine inlet temperature and fuel cell load were studied based on the simulation results. Then the effects of oxygen utilization, fuel utilization, operating temperature and efficiencies of the gas turbine components on the system performance of the RHE cycle and the EGR cycle were discussed in detail. Simulation results indicated that the system optimum efficiency for the EGR air reheating cycle scheme was higher than that of the RHE cycle system. A higher pressure ratio would be available for the EGR cycle system in comparison with the RHE cycle. It was found that increasing fuel utilization or oxygen utilization would decrease fuel cell efficiency but improve the system efficiency for both of the RHE and EGR cycles. The efficiency of the RHE cycle hybrid system decreased as the fuel cell air inlet temperature increased. However, the system efficiency of EGR cycle increased with fuel cell air inlet temperature. The effect of turbine efficiency on the system efficiency was more obvious than the effect of the compressor and recuperator efficiencies among the gas turbine components. It was also indicated that improving the gas turbine component efficiencies for the RHE cycle increased system efficiency higher than that for the EGR cycle. 相似文献
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Akihiko Shimizu Takehiko Yokomine 《International Journal of Heat and Mass Transfer》2004,47(21):4601-4614
A heat exchanger between particulate or granular materials and gas is developed. It makes use of a swirling gas flow similar to the usual cyclone separators but the difference from them is that the swirl making gas is issued into the cyclone chamber with downward axial velocity component. After it turns the flow direction near the bottom of the chamber, the low temperature gas receives heat from high temperature particles supplied from above at the chamber's center. Through this configuration, a direct contact and quasi counter-flow heat exchange pattern is realized so that the effective recovery of heat carried by particles is achieved. A model heat exchanger was manufactured via several numerical experiments and its performances of heat exchange as well as particle recovery were examined. Attaching a small particle diffuser below the particle-feeding nozzle brought about a drastic improvement of the heat exchange performance without deteriorating the particle recovery efficiency. The outlet gas temperature much higher than the particle outlet temperature was finally obtained, which is never realized in the parallel flow heat exchanger. 相似文献
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Atipoang Nuntaphan Sanparwat Vithayasai Nat Vorayos Nattanee Vorayos Tanongkiat Kiatsiriroat 《International Communications in Heat and Mass Transfer》2010
This paper presents the performance of a wire-on-tube heat exchanger of which the wire is an oscillating heat pipe. The experiments for this heat exchanger were performed in a wind tunnel by exchanging heat between hot water flowing inside the heat exchanger tubes and air stream flowing across the external surface. R123, methanol and acetone were selected as working fluids of the oscillating heat pipe. The inlet water temperature was varied from 45 to 85 °C while the inlet air temperature was kept constant at 25 °C. 相似文献
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A new type of gas burner for Stirling engine that can recover adequate heat from exhaust gas was designed based on the plate heat exchanger and low‐swirl combustion technology, which consists of three components: a cyclone, a burner, and a circular plate heat exchanger. The circular plate heat exchanger tightly wound around the combustion chamber plays a high efficiency of heat recovery role. In consideration of the radial symmetry of the burner, a three‐dimensional numerical simulation was carried out by Ansys15. The velocity distribution, temperature distribution, and pressure distribution of the combustion gas were presented respectively. Strong backflow that came from the exhaust gas around the root of the flame in the combustion chamber and a vortex below the inlet of the exhaust gas channel were found, which were beneficial for the combustion and improving the uniformity of temperature distribution. Combustion behaviors of the burner under standard operating conditions were obtained, the highest temperature was about 2200 K in burner and the exhaust gas entered the plate heat exchanger at the temperature of 1375 K and exited at 464 K, with the waste heat recovery efficiency over 65.8%. And, the air‐fuel ratio and combustion power had negligible effect on the waste heat recovery efficiency. 相似文献