带气冷器的二氧化碳地源热泵系统的性能分析

摘要

Running ground source heat pump in area with more cooling load than heating load in the long run would result in thermal unbalance in soil. Soil temperature goes up and it interferes with the function of ground source heat pump (GSHP). To solve this problem, a ground source heat pump using carbon dioxide as refrigerant is proposed, and the prediction model for the system performance was developed; the model was compared with the traditional GSHP and economic analysis was done. By using gas cooler to release heat to air and changing the operation schedule, the model can immensely improve the situation of thermal unbalance in soil. With a certain schedule it can eliminate the thermal unbalance in soil completely. Compared with the regular R134a ground source heat pump, the coupled gas cooler-ground source heat pump has lower annual operation cost by 23% and lower investment cost by 20%.%地源热泵在夏季冷负荷高于冬季热负荷地区运行会造成土壤热不平衡，常年运行导致土壤温度升高，影响地源热泵性能。为了解决这个问题，本文提出一种带有气冷器的二氧化碳地源热泵系统，建立了该系统的性能预测模型，并将该系统与传统的地源热泵系统进行了对比和经济性分析。结果表明，通过将一部分排热量利用二氧化碳气冷器排放到空气中，并根据温度条件和负荷改变热泵运行的时间表，土壤热不平衡的问题得到了显著的改善，在适当的运行方式下，土壤热不平衡可以完全消除。对比发现，耦合工作的气冷器-二氧化碳地源热泵年运行费用比普通的R134a地源热泵低23%，初始投资低20%。