Abstract:The abruptly dropping phenomenon of vacuum degree often occurs during the vacuum pump switching process of gassteam combined circulating generation unit, which seriously threatens the safety and stable operation of unit. Through analyzing the dangerous points in the vacuum pump switching process, this paper pointed out the reason of abruptly dropping of vacuum degree. After the optimizations of operational logic and operation order, the abruptly dropping phenomenon of vacuum degree was eliminated and the safety of equipment operation was improved.

Keywords:water ring vacuum pump, vacuum pump switching, abruptly dropping of vacuum degree, logic modification, operation order