基于平均性能最优的空气源热泵除霜控制方法的研究

本文选择空气源热泵机组的性能恶化点作为除霜的开始时刻,提出了一种基于平均性能最优的空气源热泵除霜控制方法。为验证该方法的可行性与适用性,采用四种不同的除霜方案对一台空气源热泵机组的除霜特性进行实验研究。针对不同的结霜工况条件,测量了翅片表面霜层厚度及机组输入功率、制热量等参数随时间的变化,并以此为基础分析了空气源热泵在整个结霜/除霜循环中的总耗功、总制热量以及平均COP的变化。实验结果表明:当空气源热泵机组选择以性能恶化点作为除霜开始时刻时,系统在整个结霜/除霜循环中的平均COP达到最大,即验证该除霜控制方法的可行性,能够用于空气源热泵机组的最佳除霜开始时刻控制。

Study on the Defrosting Control Method Based on the Optimal Average Performance of an Air Source Heat Pump

A defrosting control method based on the optimal average performance of an air source heat pump (ASHP) unit is presented. The deterioration point of an ASHP unit is selected as the defrosting initiation criterion. To verify the feasibility and applicability of the defrosting control method based on the optimal average performance, a test apparatus was established in the psychrometric rooms and the defrosting characteristics of an ASHP unit was investigated experimentally for four different defrosting initiation criteria under different frosting conditions. The frost thickness on the fins, the transient input power and heating capacity were measured. Based on the experimental results, the total heating capacity, total power consumption in the whole frosting/defrosting cycles and average COP of the ASHP unit were analyzed. The experimental results indicated that when the deterioration point of the ASHP unit is selected as the defrosting initiation criterion, the average COP in the whole frosting/defrosting cycles is the maximum, which confirmed that this defrosting initiation criterion is feasible and can be used for the optimal defrosting control of an ASHP unit.