低环境温度空气源热泵机组电子膨胀阀控制策略优化

Control strategy optimization of electronic expansion valve for lowambient temperature air source heat pump unit

为提高低环境温度空气源热泵机组制热性能和运行稳定性,对电子膨胀阀吸气过热度控制策略进行优化。通过引入补气过热度、冷凝压力等作为补偿信号对膨胀阀开度进行补偿纠偏,调整吸气侧和补气侧制冷剂流量。试验结果表明:电子膨胀阀控制策略优化后,经济器过冷度从7℃提升至23℃,机组制热量提升10.3%,制热COP提升8.3%,机组运行稳定性提高。

In order to improve the heating performance and operation stability of low ambient temperature air source heat pump unit,the control strategy of suction superheat of electronic expansion valve is optimized.By introducing vapor-injection superheat and condensing pressure,etc.as the compensation signals,the opening of expansion valve is compensated and corrected,and the refrigerant flow rates at suction side and vapor-injection side are adjusted.The test results show that after the control strategy optimization of electronic expansion,the subcooling of economizer is increased from 7℃to 23℃,the heating capacity of the unit is increased by 10.3%,and the heating COP is increased by 8.3%,as well as the operation stability is improved.