R410A直膨式太阳能热泵热水器制冷剂分布特性  

Refrigerant distribution characteristics of direct-expansion solar-assisted heat pump water heater with R410A

作　　者：孔祥强[1] 杨允国 林琳[1] 李瑛[1] 

机构地区：[1]山东科技大学机械电子工程学院,青岛266590

出　　处：《农业工程学报》2014年第12期177-183,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：山东省高等学校科技计划资助项目(J11LD63);山东省泰山学者建设工程专项经费资助项目

摘　　要：为了研究制冷剂在直膨式太阳能热泵系统中的分布和迁移特性，在建立太阳能集热/蒸发器和冷凝器的均相流动模型、压缩机和电子膨胀阀的集总参数模型和系统制冷剂充注量模型的基础上，编制了以R410A（二氟甲烷和五氟乙烷的混合物）为工质的直膨式太阳能热泵热水器系统性能模拟程序。将以R22（二氟一氯甲烷）为工质的直膨式太阳能热泵热水系统理论计算值与试验数据进行了对比分析，验证了系统数学模型的可靠性。在维持太阳能集热/蒸发器出口过热度不变的条件下，模拟分析了水箱水温、系统制冷剂充注量、压缩机转速等运行参数和太阳辐射强度、环境温度等环境参数对系统内部制冷剂分布的影响特性。模拟结果表明：制冷剂主要存在于冷凝器和太阳能集热/蒸发器内部，占系统制冷剂充注量的70%～90%；运行参数和环境参数的变化对冷凝器和太阳能集热/蒸发器内部的制冷剂分布有很大影响，而对压缩机和管道内部的制冷剂分布影响很小。研究结论可以为优化系统性能和减少系统制冷剂充注量提供科学依据。In order to study the distribution and migration properties of refrigerants in a direct-expansion solar-assisted heat pump system, a direct-expansion solar-assisted heat pump water heater （DX-SAHPWH） system, by using R410A as a refrigerant was described, which could supply domestic hot water throughout the whole year. The system mainly consisted of collectors with a total area of 4.2 m2, a compressor with a rated capacity of 0.75 kW, a hot water tank with the volume of 150 L, and an electronic expansion valve. Based on the distributed parameter and homogeneous flow models of solar collector/evaporator and condenser, the lumped parameter models of compressor and electronic expansion valve and the refrigerant charge model, a simulation program of a DX-SAHPWH system using R410A was coded, which was solved by the iterative calculation of the inlet and outlet enthalpy of electronic expansion valve and the refrigerant charge. Then the simulated data and the experimental data of the DX-SAHPWH system using R22 as a refrigerant were compared. Result proved that the mathematical model of the DX-SAHPWH system was reliable. Given the structure and meteorological parameters, initial and final water temperature, for a fixed superheat degree at the outlet of the solar collector/evaporator with a value of 5℃, the effects of various operational and environmental parameters, including water temperature, refrigerant charge, compressor speed, solar radiation, and ambient temperature, on the refrigerant distribution of the system were simulated and analyzed by means of developed model. Simulation results indicate that the refrigerant R410A mostly exists in condensers and solar collectors/evaporators, which accounts for 70%to 90%of refrigerant charge. The change of the operational and environmental parameters affects significantly the content of the refrigerant R410A in the condenser and the solar collector/evaporator, but affects slightly the content of the refrigerant R410A in the compressor and pipes. As expected, a higher re

关 键 词：制冷剂 太阳能 冷凝器 热泵 直膨式 R410A 性能模拟 

分 类 号：TK114[动力工程及工程热物理—热能工程]