HFC134a回热循环性能指标模拟及评价

运用Ａ．Ｃ．Ｃｌｅｌａｎｄ提供的制冷工质热力学参数曲线拟合方程编写程序，对新制冷工质ＨＦＣ１３４ａ应用于理论回热循环的性能指标进行模拟计算和特性评价，并与ＣＦＣ１２回热循环性能指标进行比较。结果表明：在实用的工况范围内，与制冷基本循环相比，以ＨＦＣ１３４ａ为工质采用回热循环可提高循环的理论制冷系数和单位容积制冷量；与ＣＦＣ１２对比，ＨＦＣ１３４ａ回热循环的理论制冷系数较ＣＦＣ１２回热循环的理论制冷系数为低，在蒸发温度较高的工况下，ＨＦＣ１３４ａ回热循环单位容积制冷量大于ＣＦＣ１２回热循环单位容积制冷量，在蒸发温度较低的工况下，ＨＦＣ１３４ａ回热循环单位容积制冷量小于ＣＦＣ１２回热循环单位容积制冷量。

ANALOGUE AND EVALUATION OF HFC134a' S PERFORMANCE INDEX OF THE CYCLE WITH LIQUIDLINE/SUCTION-LINE HEAT EXCHANGER

In this paper the curve equation of refrigerant thermodynamic properties providedby A. C.Cleland is applied to make procedure and at the same time to do model calculationand further more to evaluate the performance index which results from the new refrigerantHFC134a while applied to theoretic cycle with liquid-line/suction-line heat exchanger(LLSL-HX).The results show:HFC134a's cycle with the LLSL-HX can raise theoreticcoefficient of performance and volumetric refrigerating capacity compared with basic refrigerant cycle under the utility working condition. When compared with CFC12, HFC134a's theoretic coefficient of performance of the cycle with LLSL-HX is lower.HFC134a's volumetric refrigerating capacity of the cycle with LLSL-HX is higher than CFC12's at higher evaporating temperature working condition, and on the contrary, lower at lower evaporatingtemperature.