凝汽式汽轮机机组启动前抽真空时间的计算方法及应用

Calculation Method and Application of Vacuum Extraction Time before Startup of Condensing Steam Turbine Unit

凝汽式汽轮机机组启动前需要将凝汽系统通过抽气设备形成一定的真空度,而众多有关凝汽系统的资料中都没有给出通过抽气设备将凝汽系统从大气压抽取至某一真空压力时所需时间的计算方法。探究射汽抽气器或水环式真空泵这两种抽气设备将凝汽系统抽取至一定真空时的时间计算方法,同时引申至密闭容器通过恒定体积流量的抽气设备抽吸真空所需的时间计算或容量选取。

Before starting a condensing turbine unit,it is necessary to form a certain degree of vacuum in the condensing system through the air extraction equipment.However,literatures about the condensing system do not provide the time calculation method for extracting the condensing system from atmospheric pressure to a certain vacuum pressure through the air extraction equipment.This paper discusses the calculation method of the time when the condensing system is pumped to a certain vacuum by steam jet air ejector or water ring vacuum pump.At the same time,it is generally applied to the time calculation or capacity selection required for vacuum suction of closed vessels through constant volume flow of air extraction equipment.