R290直膨式太阳能热泵系统工质分布和迁移特性模拟  

DISTRIBUTION AND MIGRATION CHARACTERISTICS SIMULATION OF WORKING FLUID R290 OF DIRECT EXPANSION SOLAR-ASSISTED HEAT PUMP SYSTEM

作　　者：孔祥强[1] 李俊枭 杨允国 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：《太阳能学报》2016年第10期2585-2592,共8页Acta Energiae Solaris Sinica

基　　金：青岛市黄岛区科技项目(2014-1-40);山东省高等学校科技计划(J11LD63)

摘　　要：为了研究工质R290（丙烷）在直膨式太阳能热泵系统中的分布和迁移特性，建立太阳能集热，蒸发器和冷凝器的分布参数均相流动模型、压缩机和电子膨胀阀的集中参数模型、以及系统工质充注量模型，编制以R290为工质的直膨式太阳能热泵热水器系统性能模拟程序。模拟分析环境参数和运行参数的变化对系统内部R290分布和迁移特性的影响。模拟结果表明：R290主要存在于冷凝器和太阳能集热／蒸发器内部，占系统工质充注量的80％～90％；随着太阳辐射强度和环境温度的升高，工质R290由冷凝器逐渐向太阳能集热，蒸发器迁移，系统性能系数明显增加；随着压缩机转速增快和水箱水温的增高，工质R290由太阳能集热，蒸发器逐渐向冷凝器迁移，系统性能系数明显降低；随着系统工质充注量的增加，冷凝器内工质R290质量明显增加，集热器内工质R290质量略有增加，系统性能系数先增后减，存在一个最大值；太阳能集热，蒸发器出口过热度由3℃升至8℃时，其变化对工质R290的分布和迁移特性影响很小，且对系统性能系数的影响也很小；随着环境温度、压缩机转速和工质充注量的增加，集热器集热效率不断增加；而随着太阳辐射强度、水箱水温和太阳能集热，蒸发器出口过热度的增高，集热器集热效率不断降低。In order to study the distribution and migration property of working fluid R290 in a direct-expansion solar-assisted heat pump system, the distribution parameter and homogeneous flow model of solar collector/evaporator and condenser, the lumped parameter model of compressor and electronic expansion valve and the working fluid charge model were established. A simulation program of the direct-expansion solar-assisted heat pump water heater system using R290 was coded. The effects of the variation of environmental and operational parameters on the distribution and migration performance of working fluid R290 were simulated and analyzed. The simulation results indicate that the working fluid R290 mostly exists in condenser and solar collector/evaporator, which accounts for 80% to 90% filling amount of working fluid. With the increases of solar radiation and environmental temperature, working fluid R290 gradually moves from condenser to solar collector/evaporator, the coefficient of performance （COP） of the system increases evidently. Also, with the increases of compressor speed and water temperature in water tank, working fluid R290 gradually moves from solar collector/evaporator to condenser, the COP of the system decreases evidently. As expected, higher filling amount of working fluid makes the mass of working fluid R290 in the condenser increase significantly, and the mass of working fluid in the collector increases slightly, COP of the system firstly increases and then decreases, there is a maximum value. The effect of the superheat degree variation at the outlet of the solar collector/ evaporator on the distribution and migration characteristics of working fluid R290, also on COP of the system is very small, when it is varied between 3 ℃ and 8 ℃. The thermal efficiency of collector improves continually with the increase of environmental temperature, rotation speed of compressor and filling amount of working fluid ; However, the thermal efficiency of collector continually decreases with the increase of sol

关 键 词：工质 太阳能 直膨式 热泵 R290 数值模拟 

分 类 号：TK114[动力工程及工程热物理—热能工程]