冷却塔辅助冷却地源热泵技术经济分析

Economics Analysis of Hybrid Ground Source Heat Pump Systems with Cooling Tower as a Supplemental Heat Rejecter

由于土壤温度的全年温度变化特性,地源热泵比空气源热泵具有更高的COP。但是当建筑以冷负荷为主时,若完全依靠地源热泵来供冷,则地下埋管换热器和热泵机组的初投资均比较高,热泵系统的循环效率也较低。采用辅助冷却复合地源热泵系统,可有效降低系统投资,提高系统的运行节能效果。在部分负荷时,完全依靠地源热泵供冷,在峰值负荷或冷负荷较大时,启用辅助冷却装置,使辅助冷却装置和地源热泵机组联合运行。分析表明,采用冷却塔辅助冷却复合地源热泵系统在系统初投资和运行费用方面都具有一定的优势。

The COP of the ground source heat pump is higher than that of the air source heat pump because of the impact of the soil annual temperature change characteristics. For some cooling-dominated buildings, if the peak load of cooling is supplied only by ground exchanger, the ground source heat pump cycle coefficient is lower and initial investment cost of the system is higher. Therefore, the supplemental heat rejecter, such as cooling towers, can be utilized as assisted source to reject more heat to the air and effectively reduce investment cost of the system.In period of part cold load, the system operation just depends on the ground source. And in period of larger peak load or cold load, the system can operate cooperating with the supplemental heat rejecter. The research results show that the hybrid ground source heat pump has superiority to initial cost and operation cost.