为了对复合热源热泵热水器进行变工况运行特性分析,采用变频压缩机与电子膨胀阀,搭建了直膨式太阳能-空气复合热源热泵热水器实验装置,建立了系统数学模型,并在相同工况下进行模拟计算和实验验证,比较发现,模拟结果与实验结果吻合良好.利用验证过的数学模型进一步分析了环境温度、太阳辐射强度和压缩机频率对系统性能的影响,并制定了压缩机变频控制策略,给出了不同工况下的推荐频率和加热时长,可以为用户提供变工况运行控制指导.利用南京地区典型年气象参数,对系统在不同模式下的全年逐月运行特性进行了模拟计算并作对比分析.结果表明,相比定容量模式,系统在变容量模式下的性能系数(COP)全年平均增长49.27％,耗电量全年平均下降29.73％,节能效果显著.%To analyze the operating characteristics of hybrid heat sources, heat pump water heater, under variable condition, the apparatus of the direct-expansion solar-air source water heat pump was established using a variable capacity compressor and an electronic expansion valve. The mathematical model of this system was developed and verified. The simulated results were in good agreement with the experimental results. The validated mathematical model was used to further analyze the effect of ambient temperature, solar radiation intensity and compressor frequency on the system performance. The frequency conversion control strategy of the compressor was developed, and the recommended frequency and heating time under different working conditions were obtained, which can provide guidance to operations under variable conditions. Based on the meteorological parameters of typical meteorological years in Nanjing, the annual operating characteristics of the system in different modes were simulated and compared. The results showed that, compared with the constant capacity mode, the COP of the system in the variable capacity mode annual increased by an average of 49.27％, while the power consumption decreased by 29.73％,and the energy saving was quite remarkable.
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