跨临界CO2热泵系统最优风量实验研究
Experimental study on optimal air volume of transcritical CO2 heat pump systems
摘要：
探究在压缩机固定转速下风量对跨临界CO2循环系统性能的影响,以及确定使系统达到最大COP的最优风量,搭建了跨临界CO2热泵系统实验台。研究了室内、外风量对系统制热性能的影响,并总结出确定最优风量的方法。结果表明:跨临界CO2热泵系统在制热模式下运行,当室内风量固定时,随着室外风量的增大,排气压力与室内出风温度均呈现出先升高后趋于平稳,系统制热COP随着室外风量的增大存在一个最优值;为准确预测最优室外风量,引入最优排气压力偏离度σ和参数变化率δ作为最优室外风量的判断依据,当σ=0.48%,δ=1.4%时,系统处于最优室外风量,即对应系统在最大的COP下运行。经过实验验证,最优室外风量预测值误差在5%以内,该方法具有较高的准确性。
Abstract：
In order to explore the influence of air volume on the performance of transcritical CO2cycle system at fixed compressor speed, and to determine the optimal air volume under the maximum COP, a transcritical CO2heat pump system test bench is built. The influence of indoor and outdoor air volume on the heating performance of the system is studied, and the method to determine the optimal air volume is summarized. The results show that under the heating mode of the transcritical CO2heat pump system, when the indoor air volume is fixed, with the increase of the outdoor air volume, the exhaust pressure and the indoor air outlet temperature show a trend of rising first and then maintaining a stable state. The heating COP of the system has an optimal value with the increase of outdoor air volume. In order to accurately predict the optimal outdoor air volume, the optimal exhaust pressure deviation σ and the parameter change rate δ are introduced as the basis for judging the optimal air volume. When σ=0.48% and δ=1.4%, the system is at the optimal outdoor air volume, that is, the corresponding system operates at the maximum COP. Through experimental verification, the error of the optimal outdoor air volume prediction value is within 5%, and the method has high accuracy.
Keywords:transcritical CO2 cycle; heat pump; optimal air volume; exhaust pressure; heating COP; optimal exhaust pressure deviation; parameter change rate