闭式热源塔运行参数对热泵系统性能的影响

热源塔风机和防冻溶液循环泵是热源塔热泵系统中除压缩机外的主要耗电设备。通过改变热源塔风机和防冻溶液循环泵的工作频率，实验研究了冬季制热工况下闭式热源塔运行参数对热源塔吸热量和热泵系统性能的影响，研究结果表明，热源塔风机频率降低导致热源塔吸热量、系统制热量和热泵机组COP下降，但使系统能效比增大；热源塔吸热量随循环泵频率的增加先升高后降低并在25 Hz时达最大值，系统制热量同样随循环泵频率的增加先升高后降低，且随着风机频率的增大，制热量最大值对应的循环泵频率由35 Hz变为25 Hz；同时循环泵频率增加使热泵机组COP增加，但系统能效比减小；循环泵和风机频率均在15 Hz时，压缩机压缩比增大，压缩机效率低；系统制热量最高超过14.30 kW，热泵机组平均COP最高为3.31，系统平均能效比最高可达2.37。

Impacts of operating parameters of closed-type heating tower on the performance of heat pump system

The fan of the heating tower and circulation pump for the antifreeze solution of the heating tower are the main electrical equipment in the heating tower heat pump system, besides the compressor. By controlling the working frequencies of the fan of the heating tower and circulating pump for the anti-freezing solution, the effects of operation parameters of the closed-type heating tower on its heat absorption and the performance of its heat pump system were investigated under heating conditions in winter. The results indicated that, firstly, the reduced fan?s frequency leads to the heat absorption capacity of the heating tower reduced, as well as the system?s heating capacity and the COP. However, the SEER was increased. Secondly, the reduced frequency of circulating pump results in the heat absorption capacity of the heating tower increased firstly and then decreased, and the maximum heat absorption capacity was achieved when the frequency of the circulating pump was 25 Hz. In addition, the heating capacity of the system also increased firstly and decreased later, but with the fan?s frequency increasing, the frequency of the circulating pump which was related to the maximum heating capacity was altered from 35 Hz to 25 Hz, and the increase in frequency caused the COP increased but SEER decreased. Thirdly, when the frequency of the fan and pump dropped to 15 Hz, the evaporation temperature of the heat pump decreased, and it led the compressor works under a high compression ratio, which was not favorable for the safe operation of the heat pump. Fourthly, the maximum heating capacity exceeded 14.30 kW, the maximum COP was up to 3.31, and the maximum SEER was up to 2.37.