The steam turbine has a high exhaust temperature and high exhaust pressure.

Thread Content

The steam turbine of this unit is of the extraction type, divided into high-pressure and low-pressure sections. After maintenance, when starting the turbine, it was found that the opening degree of the inlet valve of the high-pressure cylinder was large, the pressure after each stage was high, the high-pressure discharge pressure was high, and the high-pressure discharge pressure ratio was on the low side. The exhaust temperature of the low-pressure cylinder is high, and the vacuum level is low. Start by determining that it is caused by a leak in the vacuum system. The vacuum pump is started up; after it begins to operate, the exhaust temperature of the low-pressure cylinder decreases, and the vacuum level reaches normal levels. The pressure after each stage drops, and the opening degree of the intake valves in the high-pressure cylinder decreases as well. But the problem is that the exhaust pressure remains high, the exhaust temperature continues to rise, and the exhaust pressure ratio keeps decreasing. The intake valves of the low-pressure cylinder at the site are almost fully open, resulting in a high exhaust volume. I’d like to ask everyone, what phenomenon is this?