共查询到18条相似文献,搜索用时 218 毫秒
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太阳能热动力发电系统吸热器换热管试验及数值模拟 总被引:4,自引:0,他引:4
吸热器换热管地面试验是空间太阳能热动力发电系统吸热/蓄热器研制的重要阶段,是为了验证相变材料的蓄放热性能。对以共晶盐LiF—CaF2为蓄热介质的换热管进行了27个周期共2511分钟的地面试验,包括变参数试验和稳态试验,获得了容器表面温度和工质出口温度等试验结果。利用焓法建立相变蓄热换热管试验的传热模型,采用试验参数对地面试验进行了数值模拟,得到的结果与试验结果进行了比较,两者比较接近。证明了地面单管试验的成功性,也验证了换热管传热分析软件的可靠性。 相似文献
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高温相变蓄热器是空间太阳能热动力发电系统的关键部件之一,相变材料(PCM)蓄热是其中的关键技术。对以LiF-CaF2为PCM和以干空气为工质的蓄热系统进行了地面实验,并分别建立了相应条件下填充纯PCM和泡沫复合相变材料(FCPCM)的蓄热单元管数学模型。经过数值计算得到结果表明,纯PCM蓄热单元管计算值与实验数据吻合得很好,表明了计算模型的有效性;此外,对填充纯PCM和FCPCM的蓄热单元管的计算结果进行了比较,结果表明,泡沫的填充强化了PCM的导热性能,提高了蓄热系统的热性能。 相似文献
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微重力条件下相变材料容器的二维瞬态热分析 总被引:2,自引:1,他引:2
高温相变材料是空间太阳能热动力发电系统吸热器中普遍使用的蓄热介质。基于微重力状态下的导热控制微分方程,采用焓法对相变材料容器进行了二维数值分析,对计算结果给予了讨论。 相似文献
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高温熔盐相变蓄热材料 总被引:5,自引:0,他引:5
高温蓄热技术是太阳能热动力发电系统的关键技术之一,通常利用相变材料(PCM)固液相变时的熔化潜热来蓄热。在轨道的日照期,聚能器将截取的太阳能聚集到吸热器圆柱形腔内,被吸收转化成热能,其中一部分热能传递给循环工质以驱动热机发电,其余的热能被封装在单元换热管上多个小容器内的PCM吸收储存起来,此时PCM部分或全部变为液态。在轨道的阴影期,小容器内的PCM部分或全部变为固态,储存的能量被释放出来,使出口的循环工质温度仍能维持在循环所要求的最低峰值温度上。保证空间站处于阴影期时热机仍能连续工作,保证连续供电。太阳能利用中… 相似文献
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太阳入射热流对吸热器换热的影响 总被引:1,自引:1,他引:1
空间太阳能热动力发电系统是非常有前景的未来空间能源供应系统。吸热器的入射热流分布将影响到换热管的传热以及系统的寿命,采用焓法处理相变区的传热,建立了太阳能热动力发电系统吸势器换热管三维换热模型,计算得到在轨道周期内对应三种入射热流的换热管的温度场、工质的出口温度变化、相变材料熔化率等重要的结果,并进行了比较、分析。 相似文献
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To reduce the mass and improve the thermal performance of the heat receiver, a heat pipe receiver was researched for the space solar dynamic power system. Corresponding mathematical and physical models were built, and a method was devised to provide a numerical equation by which the temperature of the containment canister outer wall, heat pipe wall temperature, working fluid exit temperature and the liquid PCM fraction of the total heat transfer tube were calculated and compared with those obtained from the baseline heat receiver. The results show that it is possible to improve receiver performance, to reduce the fluctuation of the working fluid temperature and to decrease the weight of the heat receiver. 相似文献
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In this paper, with both void cavity and phase change considered, influence of void ratio on phase change in thermal storage canister of heat pipe receiver under microgravity is numerically simulated. Accordingly, physical and mathematical models are built. A solidification–melting model upon the enthalpy–porosity method is specially provided to deal with phase changes. The change of liquid fraction with respect to void ratio and the liquid fraction distribution of different void ratios in a thermal storage canister of a heat pipe receiver are shown. Numerical results are compared with experimental ones. Research results indicate that the void cavity prevents the process of phase change significantly. Phase-change material (PCM) melts slowly during sunlight periods and freezes slowly during eclipse periods as void ratio increases. The utility ratio of PCM during both sunlight periods and eclipse periods decreases obviously as the void ratio increases. The void cavity prevents the heat transfer between the PCM zone and canister wall. The void cavity blocks the processes of both melting and solidification during cycle orbital periods. 相似文献
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Based on theoretical analysis of PCM (Phase Change Material) solidification process,the model of improved void cavity distribution tending to high temperature region is established.Numerical results are compared with NASA (National Aeronautics and Space Administration) results.Analysis results show that the outer wall temperature,the melting ratio of PCM and the temperature gradient of PCM canister,have great difference in different void cavity distribution.The form of void distribution has a great effect on the process of phase change.Based on simulation results under the model of improved void cavity distribution,phase change heat transfer process in thermal storage container is analyzed.The main goal of the improved designing for PCM canister is to take measures in reducing the concentration distribution of void cavity by adding some foam metal into phase change material. 相似文献
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IlltroductionSolar dynamic power modules (SDPM) with phasechange material (PCM) is a vital solution to ensureuninterrupted power supply for low-earth orbitapplication. The advantage of SDPM is its longerlifehme and higher efficiency. Longer lifetime results insubstanhal savings in hardware replacement, launch, andon-orbit installation costs. Because of SDPM's higherefficiency, its solar collection area is only about 25percent of that for a PV system. This would allowspacecraft operatin… 相似文献
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Numerical simulation and experiment investigation on unit heat exchange tube for solar heat receiver
Haiting Cui Yuming Xing Yanshu Guo Zhenhui Wang Haochen Cui Xiugan Yuan 《Solar Energy》2008,82(12):1229-1234
In this paper, numerical simulation and experimental investigation on unit heat exchange tube for solar heat receiver are reported. Based on enthalpy method, a physical and numerical model of the unit heat exchange tube was developed. An experimental system of solar simulator test rig was also set up with high temperature LiF–CaF2 eutectic mixture as the PCM and dry air as the working fluid. The hardware, test procedures, and test results from these experiments are also discussed. The simulating orbit data was numerically analyzed and compared with test data. Canister thermal performance can be predicted well by numerical canister analyses. The results show that the output temperature of the gas of the working fluid tubes meets the expected demand during the sunlight and eclipse period and the maximum temperature and average temperature of the PCM container were all under the safe range. 相似文献
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To solve the problems associated with employing the single melt point phase change material in a heat receiver for the NASA 2 kW solar dynamic power system, this paper presents a practically easy to carry-out PCM receiver model composed of three different phase change temperature materials together with the corresponding physical model. A numerical solution is also given by which the maximal temperature for heat transfer, working fluid exit temperature, and liquid PCM fraction of the total heat transfer tube in whole are calculated. Furthermore, the results are compared with those obtained from the single PCM heat receiver. The results show that it is possible to improve the receiver performance and to reduce both the fluctuation of working fluid temperature and the weight of the heat receiver. All results of the calculation can be used to guide the heat receiver design. 相似文献