新型混风热泵热回收新风机性能分析

Analysis on Performance of Novel Dedicated Outdoor Air System with Mixed Air Recovery Heat Pump

在空间受限的应用场合常采用整体式排风热泵热回收新风机。由于排风风量受限于新风量,该种新风机的冷凝温度较高,送风温度偏高,效率较低。本文提出了一种混风冷凝加回风过冷的新系统;在不改变排风盘管总换热面积的前提下,将过冷段与冷凝段分离布置,使得较低温度的室内回风先经过过冷盘管,再与新风混合后经过冷凝排风盘管。仿真分析表明,新系统有效改善了冷凝温度过高的问题,系统效率显著提高。回风过冷使得过冷度更大,单位制冷量提高,能够有效降低送风温度,达到等焓送风甚至等含湿量送风,可完全消除新风热湿负荷。

In space-constrained applications, the packaged dedicated outdoor air system equipped with exhaust air heat pump is often used. As the exhaust air volume rate is limited by the supply air volume rate, this kind of system has the problems of high condensing temperature, high air supply temperature and low system efficiency. A novel system with mixed air condensation and subcooled return air is therefore proposed. Without changing the size of the exhaust coil, its subcooling section is spatially separated from the condensing section. The lower temperature return air passes through the subcooler first and then mixes with the outdoor air before entering the condenser. System simulation showed that the novel system can significantly lower the condensing temperature and improve the system efficiency. Meanwhile, the return air subcooler increases the subcooling and cooling capacity, which can remarkably lower the supply air temperature. This system can reach the same enthalpy or even the same absolute humidity as the indoor air, and the sensible and latent heat load of outdoor air can be completely removed.