沼气机驱动的风冷热泵系统变工况性能

Performance of biogas engine driven air source heat pump system under variable conditions

为高效利用沼气资源并减轻环境污染,构建了基于沼气机驱动的风冷热泵能源综合利用实验装置,重点研究了蒸发温度、冷却水量、沼气机转速等参数对系统性能的影响。实验测试结果表明:冷凝器总负荷随蒸发温度及冷却水量的增加而增大,但增幅较小;回收的沼气机余热随蒸发温度的升高而降低,但降幅较小,通过增大冷却水量可以提高沼气机余热的回收率,同时也增大了系统总供热量;冷却水量对系统性能系数(COP)的影响不具有单调性,在同一工况下,存在一个最佳冷却水量;冷却水量对系统一次能源利用率(PER)的影响幅度不同,冷却水量大时,PER的增幅反而较小。实验工况下,系统COP最高可达5.15,PER最高可达1.68。

To efficiently use biogas resources and reduce environmental pollution, an experimental device for energy comprehensive utilization of airsource heat pump driven by a biogas engine was constructed, focusing on the effects of evaporation temperature, cooling water flow rate, biogas engine speed and other parameters on system performance. Experiment results show that while total condenser load increases with rising evaporator temperature and cooling water flow rate, the rate of increase is small. The recovered biogas engine waste heat decreases with rising evaporator temperature although the rate of decrease is not large, but cooling water flow rate increase can improve the recovered rate of biogas engine waste heat and the total heating capacity of the system at the time.Effect of cooling water flow rate on system coefficient of performance(COP) is not monotonic, and there exists an optimum cooling water flow rate under certain working conditions. Different cooling water flow rate has different effect on primary energy ratio(PER), and lesser PER increase corresponds larger cooling water flow rate. Under the experiment conditions, the maximum system COP and PER are 5.15 and 1.68 respectively.