微通道蒸发器与常规蒸发器的制冷特性比较

摘要

Microchannel has attracted a widespread attention due to its good heat transfer properties. Using R404A as a refrigerant, this paper aims to compare the properties of refrigeration system between microchannel evaporator and conventional evaporator from two aspects: filling quantity and heat load. It can be seen from the experiment result that pressure drop and outlet temperature of microchannel evaporator and conventional evaporator reach the lowest point at 1400g filling quantity, which are 0.04MPa,-36℃ and 0.06MPa,-28℃ respectively and the highest COP is 0.64 and 0.48 for each. Moreover, COP reaches its highest with the number of 0.84 and 0.63 when heat load is 800W. After comparing with the conventional evaporator, microchannel evaporator is far better, except that only when the refrigerant charge is surpassing 1300g, the two evaporators show the temperature drift phenomenon.%微通道由于很好的换热物性，受到广泛的关注。以R404A作制冷剂，从充注量和库内热负荷两方面详细比较了微通道蒸发器与常规蒸发器制冷系统的特性。实验结果表明，微通道蒸发器与常规蒸发器在充注量1400g时蒸发器压降和出口温度均达到最低，分别为0.04MPa、-36℃和0.06MPa、-28℃，COP最大值分别为0.64和0.48。热负荷800W时COP达到最大值，分别为0.84和0.63。与常规蒸发器比较后，发现微通道蒸发器性能优于常规蒸发器。其中，制冷剂充注量超过1300g时，两种蒸发器均出现蒸发温度漂移现象。