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1.
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   

2.
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   

3.
通道形面对PSR性能影响的分析   总被引:1,自引:0,他引:1       下载免费PDF全文
针对一种新型的紧凑式换热器--一次表面换热器(PSR),分析了分别由椭圆、正弦曲线和抛物线构成板片波纹对芯体性能的影响。结合一台用于燃气轮机回热器的一次表面换热器样机的设计,给出了三种板片波纹形式的PSR芯体的主要性能,并通过与相应的板翅式芯体的对比,表明这种换热器的优越性。  相似文献   

4.
LNG冷能在燃气轮机进气冷却系统中的应用   总被引:1,自引:0,他引:1  
进气温度对燃机效率的影响非常大,如果利用LNG作为低温冷源,实现对燃气轮机进气的冷却,可提高燃机功率和LNG的利用效率。文中建立了翅片管式换热器的传热模型,计算换热器传热参数,为LNG在燃机进气冷却中的应用做铺垫。  相似文献   

5.
杜娟丽  胡晓波  崔国民 《节能技术》2013,(6):508-511,530
两股流板翅式换热器因具有良好的换热性能,在许多工业领域备受青眯.但因换热器在工作过程中受到各种因素的干扰,加之复杂的换热过程,使得很难获得良好的控制品质.所以本文在传统控制方法的基础上提出了精确数学控制方法,其核心技术是引入反问题算法,并通过对两股流板翅式换热器的实验,取得良好的控制效果,证实了精确数学控制是实现板翅式换热器高质量控制的一种新型、高效的控制方法.  相似文献   

6.
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   

7.
板翅式换热器翅片及隔板动态特性分析   总被引:1,自引:0,他引:1  
基于板翅式换热器翅片的非稳态导热方程,计算分析了翅片的动态特性,认为翅片的不稳定传热过程相对于换热器其它过程特征时间无限小,因此可以不考虑翅片的动态特性,从而简化了板翅式换热器动态模型,通过分析换热器动态过渡过程表明:隔板的热容对板翅式换热器的动态特性的影响是不容忽略的。  相似文献   

8.
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   

9.
多股流板翅式换热器温度交叉的数值分析   总被引:1,自引:1,他引:0       下载免费PDF全文
以平行多股流板翅式换热器为研究对象,给出了考虑翅片旁通作用的多股流板翅式换热器流体和翅片的能量方程。在改变多股流板翅式换热器各通道的流体参数、流动方式及换热器的结构参数等情况下,对能量方程进行数值求解,获得了各通道的流体温度分布情况及相邻通道的流体温度差,并分析了流体参数、流动方式和结构参数的变化对相邻通道流体温度交叉的影响。  相似文献   

10.
根据轧钢加热炉的实际情况,把传统管式换热器换成了板式换热器。新型板式换热器对传统管式换热器的外观和内部结构做了改进,以适应加热炉的烟气利用,可以用在高温气体的余热利用。相对管式换热器,板式换热器在相同的换热面积下具有占地少、体积小的优点,能节约材料和成本。在加热炉的烟气余热利用上,板式换热器算是创新应用,在实际使用中效果良好。  相似文献   

11.
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   

12.
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   

13.
建立了多股流板翅式换热器动态数学模型,通过换热器入口温度及流量阶跃的改变,模拟过渡过程中温度场的动态响应,利用温差场均匀性因子对多股流换热器过渡过程动态特性进行了评价,通过分析内部温度场与速度场的协同关系,揭示温差场在动态过程中的变化特征.将温差场均匀性因子与过渡时间结合,建立了自组织能力系数,并对多股流换热器控制品质进行了分析.多股流换热器在流量阶跃时,温差场均匀性因子平缓迁移,而温度阶跃时变化剧烈且存有极值.多股流换热器自组织系数越大,越易达到新的热平衡.  相似文献   

14.
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   

15.
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   

16.
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   

17.
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   

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