分液冷凝器在HFC410A空调系统的替换实验研究

汽液分离式冷凝器是一种管内高效冷凝换热器,它采用了一些强化换热手段,如多管程平行流冷凝、中间排液以及优化管子数目等。这里将该分液冷凝器用于HFC410A空调系统中,并进行了性能测试。结果表明:使用分液冷凝器后,HFC410A的制冷能力仅为原系统的96.4%,EER值为原来的93.8%,该分液冷凝器无法实现替换目的。通过分析发现,HFC410A对分液冷凝器的热力性能影响较大,HFC410A在分液冷凝器的气液分离效果变差,不再维持HCFC22在分液冷凝器中表现出来的近等温冷凝过程;在相同的冷凝温度下,HFC410A系统的循环质量流量较HCFC22系统减少1.2%~9.2%时,分液冷凝器的压降提高39.1%~52.6%。

Experimental Investigation of HFC410A Air-conditioning System Substituted for Liquid-vapor Separation Condenser

Liquid-vapor separation condenser (LSC) is a kind of heat exchanger with high in-tube condensation heat transfer coefficient. It adopts some enhancement means, such as the parallel flow condensation with multi tube passes, draining away condensate between two adjacent passes and optimization of the tube number of refrigerant route. In the present paper, the LSC was applied in an HFC410A air conditioning system and measured in the standard air enthalpy difference lab. Compared with the prototype HFC410A system, the cooling capacity and EER of the LSC system were 96.4% and 93.8% respectively. The results present the LSC is a poor substitution for the original condenser. The analysis shows HFC410A reduced the performance of LSC by weakening the liquid-vapor separation effect, which results in the condensation process in HFC410A LSC no longer keeping the quasi-constant wall temperature as that in the HCFC22 LSC. The looping refrigerant mass flux in the HFC410A system was 1.2%~9.2% lower than that of HCFC22 system at the same condensation temperature, and the pressure drop of the LSC in HFC410A system was seen to increase by 39.1%~52.6%.