低环温空气源热泵机组低温静置后启动制热失效分析

Failure Analysis of Start-Up Heating of Low Ambient Temperature Air Source Heat Pump Unit after Low Temperature Standing

本文主要针对低环温空气源多联热泵机组在低温-30℃以下经过长时间静置后,由于冷媒大量迁移,液态冷媒集中堆积在外机系统,机组启动后为了防止机组大量回液,机组自带压缩机降频等保护措施限制冷媒循环流量,从而一引起制热启动后长时间出现制热功能失效,严重时长期吹冷风的问题,本文针对此通过理论分析,并结合实验过程数据做过程实践分析,并最终找出冷媒量、环境温度、连接管长度等是影响静置启动后制热功能恢复所需时间的重要影响因素,最后为低温机组静置启动后缩短失效时间提供解决方法。

This paper mainly aims at the problem of heating function failure for a long time after heating start-up due to the large migration of refrigerant and the concentrated accumulation of liquid refrigerant in the external system after the low ambient temperature air source multi connected heat pump unit is standing at a low temperature of-30℃for a long time.In order to prevent a large amount of liquid return of the unit after the unit is started,the unit is equipped with protective measures such as compressor frequency reduction to limit the circulating flow of refrigerant,Through theoretical analysis and combined with the experimental process data,this paper finally finds out that the amount of refrigerant,ambient temperature and the length of connecting pipe are important factors affecting the time required for the recovery of heating function after static startup,and finally provides a solution for shortening the failure time after static startup of low-temperature unit.