膜式全热回收装置结霜特性实验研究OA

Experimental study was conducted on the frosting critical values(critical indoor return air rela-tive humidity,critical outdoor fresh air temperature),influencing factors,and frosting characteristics of membrane-based total heat recovery devices in se-verely cold regions.When the indoor return air tem-perature and outdoor fresh air relative humidity are constant,the critical indoor return air relative humidity increases with the rise of the critical outdoor fresh air temperature.At a lower critical outdoor fresh air tem-perature,the range of critical indoor return air relative humidity that leads to frosting is larger within the varia-tion range of fresh air and exhaust air volume.When the outdoor fresh air relative humidity and the volume of fresh air and exhaust air are constant,the critical in-door return air relative humidity also increases with the rise of the critical outdoor fresh air temperature.At lower critical outdoor fresh air temperatures,the range of critical indoor return air relative humidity that leads to frosting is larger within the variation range of the in-door return air temperature.Compared to the indoor re-turn air temperature,the volume of fresh air and ex-haust air has a more significant impact on thermal effi-ciency.When the indoor return air temperature and hu-midity,outdoor fresh air humidity,and fresh air and ex-haust air volume are constant,the lower the outdoor fresh air temperature,the longer the defrosting time of the total heat exchange membrane.Under frost-free conditions,the variations of sensible heat efficiency,la-tent heat efficiency,and total heat efficiency over time are very small.Under frosting conditions,all three effi-ciencies decrease with time,and the decrease range of latent heat efficiency is significant.