With the advantages of high level of integration, high heat exchange efficiency, and low pressure drop penalty in refrigerant side, the refrigerant charge can be reduced effectively in microchannel evaporator, and the size and weight of heat exchanger also can be reduced, therefore the system energy efficiency can be improved effectively. In this work, an experimental system was designed and set up to research the performance of microchannel evaporators. The inlet and outlet temperature distribution of microchannel flat tube were measured. And the variations of inlet and outlet temperature difference, pressure drop, input power, cooling capacity, coefficient of performance with environmental chamber were also analyzed. In addition, the experimental results were compared with conventional finned-tube evaporators under the conditions of ambient chamber temperature in the range from 18 to 23℃. The experiment results indicated that microchannel evaporator had better distribution behavior of refrigerant and can improve the temperature uniformity of air-condition vent. The pressure drops of microchannel evaporator and finned-tube evaporator increased with the increasing of environmental chamber temperature. As the reason that refrigerant charge of microchannel evaporator was lower than finned-tube evaporator and the refrigerant flow path was also shorter than finned-tube evaporator, the maximum pressure drop between two evaporators was 111 kPa under the same temperature. The average pressure drop penalty of microchannel evaporator was reduced by 33.9% compared to the finned-tube evaporator. The compressor power consumption can be reduced by using microchannel evaporator. The system input power of microchannel evaporator was lower than that of finned-tube evaporator and the maximum value was 4.12%. Compared with finned-tube evaporator, the cooling capacity of microchannel evaporator increased by 2.95% and the system coefficient of performance improved by 6.69% under the same temperature of environmental chamber from 18 to 23℃. Based on the above researches, these experimental results can provide data support for application of microchannel evaporator.
Jinli LU Yajin LIU Yafang HAN Bangjie CHI Fuping QIAN
. Experimental test on heat exchanger performance of air conditioning with microchannel evaporator[J]. The Chinese Journal of Process Engineering, 2019
, 19(4)
: 661
-667
.
DOI: 10.12034/j.issn.1009-606X.218313
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