Abstract Heat pump systems have been used for decades in refrigeration and the upgrading of heat to temperature levels demanded by consumers. Private housing in Northern Europe and other countries is moving away from direct electric heating, combustion-based heating and even district heating in favour of heat pumps that use a cheap renewable heat source and electricity. The system purchase is motivated by an attractive coefficient of performance (COP), the option to reverse the heat pump operation from heating during winter to cooling during summer, and the increasing availability of (cheap) zero-CO2 electricity. Assessment of the energy efficiency of heat pump systems using exergy analysis is complicated by features of the heat reservoirs, such as humidity of air in a building envelope, becoming important besides temperature levels. In modern buildings, exhaust air heat recovery (EAHR) systems replace the air inside a building every few hours, with a net in- or outflux of humidity as side-effect. In this paper, an exergy analysis is presented that quantifies energy efficiency of a heat pump system as partly determined by the humidity of a building envelope being heated using a ground source or air source heat pump. Humidity control introduces a significant energy penalty. As shown, an EAHR unit can result in a significant increased exergy efficiency, adding to the benefits offered by the heat pump, depending on indoor versus outdoor temperature and humidity, and whether a ground source or air source heat pump is used. Using weather data for 2018, during the coldest months a ground heat source heat pump is clearly more efficient than an air source heat pump for maintaining a modern housing space in Finland at 22 °C and 50% relative humidity year-round. Exergy (in practice electricity) consumption is 20% higher for an air source heat pump compared to a ground source heat pump, with maximum exergy efficiencies of 14% and 11.5%, respectively. Integration with an EAHR system can add up to 20%-points to the exergetic efficiency, irrespective of the type of heat pump making also that a powerful investment.

中文翻译：

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空气湿度对家用热泵火用效率的影响

摘要 几十年来，热泵系统一直用于制冷和将热量升级到消费者所需的温度水平。北欧和其他国家的私人住宅正在摆脱直接电供暖、燃烧供暖甚至区域供暖，转而使用使用廉价可再生热源和电力的热泵。购买系统的动机是有吸引力的性能系数 (COP)、将热泵运行从冬季加热到夏季冷却的选项以及（廉价）零二氧化碳电力的可用性增加。使用火用分析评估热泵系统的能源效率是复杂的，因为热库的特征，例如建筑围护结构中的空气湿度，除了温度水平之外变得很重要。在现代建筑中，废气热回收 (EAHR) 系统每隔几个小时就会更换建筑物内的空气，但会产生湿气的净流入或流出。在本文中，提出了一种火用分析，该分析量化了热泵系统的能源效率，部分由使用地源或空气源热泵加热的建筑围护结构的湿度决定。湿度控制引入了显着的能量损失。如图所示，EAHR 装置可以显着提高火用效率，增加热泵提供的好处，具体取决于室内与室外的温度和湿度，以及使用地源热泵还是空气源热泵。使用 2018 年的天气数据，在最冷的月份，地热源热泵显然比空气源热泵更有效，可将芬兰的现代住宅空间全年保持在 22 °C 和 50% 的相对湿度。与地源热泵相比，空气源热泵的火用（实际上是电力）消耗高出 20%，最大火用效率分别为 14% 和 11.5%。与 EAHR 系统集成可以将热效率提高 20%，无论热泵的类型如何，这也是一项强大的投资。