二级管网安全阀常开原因及回座、整定压力设定

Reason for Frequent Opening of Safety Valve of Secondary Circuit and Setting of Reseating Pressure and Set Pressure

结合某座设置在居民楼地下室的热力站,对二级管网安全阀的选型进行复核,分析安全阀阀瓣不回座原因,提出解决方案。出现安全阀持续排水的主要原因是安全阀开启后阀瓣不回座,随着补水泵补水,热水由安全阀流出。解决方案为:将安全阀回座压力选定在定压压力与补水泵启动压力之间。在二级管网回水压力达到整定压力条件下校核承压最大用户的承压不高于设计压力,从而确定回座压力、整定压力。采取向安全阀生产厂家定制的方法,定制回座压力、整定压力满足要求的安全阀。

Combined with a substation set in the basement of the residential building,the type selection of the safety valve of the secondary circuit is reviewed,and the reason why the disc of the safety valve does not re-seat is analyzed,and a solution is proposed.The main reason for the continuous drainage of the safety valve is that the disc does not re-seat after the safety valve is opened.The hot water flows out of the safety valve as the make-up water pump operates.The solution is that the reseating pressure of the safety valve is determined between the pressurization pressure and the starting pressure of the make-up water pump.Under the condition that the return water pressure of the secondary circuit reaches the set pressure,it is checked that the pressure of the largest user is not higher than the design pressure,so as to determine the reseating pressure and the set pressure.The safety valve which is customized to the safety valve manufacturer is adopted,and the reseating pressure and the setting pressure meet the requirements.