Energy and Buildings ( IF 6.7 ) Pub Date : 2021-09-27 , DOI: 10.1016/j.enbuild.2021.111511 Samuel Boahen 1 , Selorm Kwaku Anka 2 , Kwang Ho Lee 3 , Jong Min Choi 4
Cascade multi-functional heat pumps are becoming popular due to their ability to simultaneously provide cooling, heating, and hot water. In this study, the performance characteristics of a water-to-water cascade multi-functional heat pump designed to provide heating, hot water, and simultaneous heating and hot water during the winter season are analyzed according to variation in secondary fluid temperature. The simultaneous heating and hot water cycle was optimized to meet the design heating and hot water capacities by increasing the compressor speeds of the low stage and high stage cycles above those in the heating and hot water cycles. An increase in the outdoor heat exchanger entering water temperature increased the performance of the cascade multi-functional heat pump in all operating modes, while an increase in the indoor heat exchanger entering water temperature resulted in a decrease in the performance of the cascade multi-functional heat pump in all operating modes except the capacity of the hot water cycle in heating-hot water mode. Furthermore, an increase in the hot water entering water temperature resulted in a decrease in the performance of the cascade multi-functional heat pump. The cascade multi-functional heat pump in heating-hot water mode showed similar performance trends as individual heat pumps for space heating and hot water generation and provided much stable hot water capacity at varying outdoor entering water temperature conditions. Cascade multi-functional heat pumps have the potential to provide better energy efficiency at higher heating and hot water loads, and can, therefore, be used for simultaneous space heating and hot water generation in winter seasons.
中文翻译:
冬季梯级多功能热泵的性能特点
级联多功能热泵因其能够同时提供冷却、加热和热水的能力而变得流行。在这项研究中,根据二次流体温度的变化,分析了设计用于在冬季提供暖气、热水和同时采暖和热水的水对水梯级多功能热泵的性能特征。通过将低级和高级循环的压缩机速度提高到高于加热和热水循环中的压缩机速度,对同时加热和热水循环进行了优化,以满足设计加热和热水容量。室外换热器进水温度的增加提高了复叠式多功能热泵在所有运行模式下的性能,而随着室内换热器进水温度的升高,除热-热水模式下热水循环容量外,所有工况下复叠式多功能热泵的性能均有所下降。此外,热水进水温度的增加导致了复叠式多功能热泵的性能下降。采暖热水模式的梯级多功能热泵表现出与单独热泵相似的性能趋势,用于空间采暖和热水生产,并在不同的室外进水温度条件下提供非常稳定的热水容量。级联多功能热泵有可能在更高的供暖和热水负荷下提供更好的能源效率,因此,