R744混合自然工质热泵系统特性研究

Study on the Performance of a Heat Pump System Using R744-based Natural Binary Mixture

采用EES(Engineering Equation Solver)软件建立了跨临界循环混合工质热力学模型,以中原地区典型城市—郑州的气象和水文条件模拟R744/R290自然混合工质热泵系统的性能,基于计算数据,对总当量变暖影响(TEWI)进行了估算.结果表明:在设计工况下,不带回热器跨临界R744/R290热泵热水装置的最优制热COP可达4.104.经计算,用于郑州地区的年平均制热COP为4.202.与其他常规能源热水器相比,R744/R290热泵热水装置CO2排放量平均可减少36.39%.论文还计算并探讨了回热器和压缩机等熵效率对热泵系统性能的影响.综合分析,R744/R290热泵热水装置具有能效高且环保的优点.

The thermal model using EES （Engineering Equation Solver） is developed, and then the system performanee of transeritical R744/R290 heat pump water heater is simulated with the meteorologieal and hydrological conditions in Zhengzhou, the typical city in eentral China. The total Equivalent Warming Impaets （TEWIs） are calculated with the simulation datum. The results show that the maximum heating system COP is 4. 104 under the design condition without consideration of internal heat exchanger. When R744/R290 heat pump water heater is on operation in enetral China, the mean annual heating COP of 4. 202 ean be achieved. Compared with the hot water heater using other energy, the R744/R290 heat pump water heater is averagely decreased by 36.39% in the CO2 emissions. It is also cacalated and diseussed how the internal heat exchanger and compressor isentropie efficiency influence the system performances respeetively. Therefore, the R744/ R290 based heat pump water heater is characterized by a higher energy efficieney and a very effeetive way for remarkably reducing CO2 emissions.