基于最佳除霜控制点的空气源热泵新型电流除霜控制方法开发与验证

Development and Validation of a New Electric Current Defrosting Control Method of Air-source Heat Pump Based on the Optimal Defrosting Control Point

空气源热泵室外风机电流随蒸发器结霜程度而变化,采用电流间接测霜具有成本低、灵敏和易于应用等优势。本文以开发适宜工程应用的高效除霜控制方法为目标,开展空气源热泵新型电流除霜控制方法研究。首先,通过人工环境室测试,系统分析了不同结霜工况下空气源热泵室外风机电流、风机电流增量、平均电流增长速率的变化规律,提出以风机电流增量为除霜控制参数,以平均电流增长速率为结霜工况判断依据;然后,基于最佳除霜控制点理论,确定不同结霜工况的最佳除霜控制阈值,开发除霜控制策略并应用于山东临沂市某实际供暖工程。测试结果表明,新型除霜控制方法能准确判断结霜工况,按需除霜,相比原厂除霜控制方法,机组除霜频次降低39.8%,能效提升12%。

The electric current of outdoor fan of air-source heat pump varies with frosting degree of evaporator,and adopting indirect electric current measurement of frost has advantages of low cost,sensitivity and easy application.This paper aims at developing a high efficient defrosting control method that is suitable for engineering application,and carrying on a research of a new electric current defrosting control method of air-source heat pump.Firstly,via the tests in climatic chamber,systematically analyzed the change rules of outdoor fan current,fan current increment and average current growth rate under different frosting conditions of air-source heat pump,afterwards using the defrosting control parameter of fan current increment was proposed,and average fan current growth rate was taken as the judgment basis of the frosting condition.Then,based on the theory of the optimal defrosting control method,determining the optimal defrosting control parameter in different frosting conditions,and developing defrosting control strategy,which applied in practical heating engineering in Linyi,Shandong Province.The test result indicates that the new defrosting control method can accurately judge the frosting condition,and defrost at the needy time.Comparing the new defrosting control method with the original one,the defrosting frequency decreased by39.8%,and the energy efficiency raised by 12%.