不同角度反V型蒸发器变风量下换热性能的研究

Experimental study on heat transfer performance of inverse V type evaporator with variable air volume at different angles

机房空调的送风方式主要分为两类,即上送风(V型)和下送风(反V型)。通过焓差实验法研究了机房空调中不同角度反V型蒸发器的换热性能。所研究的角度分别为32.5°、39°、45.5°,并且研究了三种角度蒸发器分别在风量百分比为100%、90%、80%、70%时四种情况下的换热性能。对比分析了各种工况下的制冷量、能效比,并且从蒸发温度以及压缩机的吸、排气温度及压力、冷凝温度等方面分析造成这种差异的原因。研究结果表明,当夹角为39°和45.5°时,蒸发温度约高2℃,系统的换热性能较好。与角度32.5°相比,当风量百分比为100%和90%时,最大制冷量均提高2%左右;当风量百分比为80%和70%时,最大制冷量分别提高5.7%和6%,能效比分别提高了3.5%和6.7%。

The air supply mode of the air conditioner in the computer room is divided into two kinds, that is the upper air supply （ V type） and the lower air supply （ anti V type）. In this paper, the heat transfer performance of inverse V evaporator with different angles in room air conditioner was studied by enthalpy difference test. The angles studied in this paper were 32.5 de- grees, 39 degrees and 45.5 degrees respectively, and the heat transfer performances of three kinds of angle evaporators at four percentages of 90%, 80%, 70% and 100% respectively were studied. Comparative analysis of the refrigeration capacity under various working conditions and the energy efficiency ratio was conducted. The causes of the difference from the evaporation tem- perature and the compressor suction, exhaust temperature and pressure and condensing temperature etc. were analysed. The resuits show that when the angles are 39 degrees and 45.5 degrees, the evaporation temperature is about 2°, the heat exchange system has good performance. Compared with the angle of 32.5 degrees, when the volume percentage of 100% and 90% , the maxi- mum cooling capacity increases by about 2% ; when the volume percentage of 80% and 70%, the maximum cooling capacity in- creases by 5.7% and 6% , the energy efficiency ratio increases by 3.5% and 6.7% respectively.