分体式冷凝排风新风机组的制冷剂充注量优化

Refrigerant Charge Optimization in a Split Condensing Exhaust Air Heat Recovery Unit

冷凝排风新风机组,也称为热泵式排风热回收新风机组,按结构分为整体式和分体式。分体式冷凝排风机组布置灵活,能满足不同客户的安装需求。然而,分体式冷凝排风机组室内外机之间的长连接管使得制冷剂充注量对机组性能的影响与整体式机组不同。实际生产中,为了加工的方便,同一型号的所有机组都充注相同质量的制冷剂,即不考虑工程应用时分体式机组中由膨胀阀安装位置和制冷剂连接管长度带来的制冷剂充注量影响,由此造成了机组性能的衰减。本文通过仿真结合实验,对分体式冷凝排风新风机组的制冷剂充注量进行优化,得出膨胀阀安装于室内侧的机组性能更好,为工程应用提供依据,并获得了综合制冷和制热工况下连接管长变化范围5 m^15 m的系统最佳制冷剂充注量,为实际生产提供有价值的普适性设计方法参考。

Split condensing exhaust air heat recovery unit is also called as outdoor air handling unit with exhaust airheat pump.According to the structure,it can be packaged or split.The split system is easy for installation and cansatisfy customer's need.However,different from packaged system,its performance is influenced by refrigerantcharge due to the variable length of connection pipes between the indoor and outdoor units.In the actual production,for the convenience of processing,all units of the same type are filled with the same quality of refrigerant,regardlessof the refrigerant charge influenced by the expansion valve installation location and refrigerant connection tube insplit unit,which results in the performance reduction.Through simulations and experiments,we optimized therefrigerant charge in a split condensing exhaust air heat recovery unit,which is based on expansion valve mountingposition and the refrigerant connection pipe length.The results indicated that,the expansion valve is better installedin the indoor unit,which provide the basis for engineering applications,and the optimal refrigerant charge wasobtained to meet the integrated cooling and heating performance under varying connection pipe from5m to15mlong,providing reference for valuable universal design method in actual production