Abstract:

To improve the performance of the heat pump water heater, CO₂ is used to develop a heat pump water heater using the hybrid heat sources for its advantages of environment-friendly and the unique thermodynamic properties. The steady state models, including heating collector/evaporator, compressor, gas cooler, regenerator and throttle, are established according to the lumped parameter method. The operating characteristics of the CO₂ heat pump water heater using the hybrid heat sources are analyzed, and the changes of COP were proposed on varied structural parameters, pressure, temperature of CO₂,environmental temperature and solar radiation. The results show that a higher COP is achieved for the CO₂ heat pump water heater at the appropriate structure parameters, enviromental parameters and operation parameters. The value of COP is 6.0 while the ambient temperature and the solar radiation are 35℃ and 900 W·m^-2 respectively.

Key words: CO₂, hybrid heat source, COP, thermodynamic property, environment

摘要：

为提高热泵热水器的能源利用效率,充分利用CO₂环保和独特的热力学性质等优势,设计了一种以CO₂为工质的复合热源热泵热水器。针对该复合热源CO₂热泵热水器的结构特点,运用集总参数法分别建立了集热/蒸发器、压缩机、气体冷却器、回热器和节流阀的稳态数学模型。通过所建模型分析了复合热源CO₂热泵热水器的COP、制热量及耗电量随着不同的结构参数、压力、CO₂温度、环境温度及太阳辐射强度等的变化规律。结果显示,该复合热源CO₂热泵热水器在适当的结构参数、环境参数以及运行参数下能有较高的性能值,在环境温度35℃,太阳辐射强度900 W·m^-2的工况下,系统的平均COP达到了6.0。

关键词: CO₂, 复合热源, COP, 热力学性质, 环境