The problem of low exhaust pressure in backpressure steam turbines
Thread Content
This post was last edited by sxf1028102800 on 2023-2-16 at 23:30. The turbine in this device is driven by steam at 3.6 Mpa and a temperature of 420 degrees. According to the information I’ve found, if the exhaust pressure of the turbine falls below 0.7 Mpa, an interlock mechanism is activated. What are the common causes of low exhaust pressure? What are the hazards of low exhaust pressure at the same time? Thank you, please discuss it among yourselves
The exhaust pressure is primarily influenced by the pressure in the low-pressure steam pipeline network; a low exhaust pressure may result in an increased load on the final impeller
1. Inspect the turbine exhaust pipeline. Check the exhaust pipes for any leaks; if there are any, repair them promptly ； II. Check each system and readjust the pressure differences across them. Inspect all steam pipelines and exhaust pipelines, readjust the corresponding pressure differences to ensure that the steam has sufficient pressure to enter the turbine ； III. Check the steam pressure at the impeller section. Check the steam pressure at the impeller area; it should generally be maintained around 0.5 MPa. If it is lower than this value, the make-up pressure can be increased. IV. Check the outlet pressure setting of the exhaust safety valve. Check the outlet pressure setting of the exhaust safety valve; if it is too high, this value needs to be reduced to ensure that the exhaust pressure does not become excessive ； V. Check for gas leaks near the combustion chamber. Check for any gas leaks near the combustion chamber; if there are any, they need to be repaired promptly.
In most cases, this situation is caused by system pressure, and it is necessary to adjust the entire pipeline network
Our plant uses turbines with a pressure of 3.43 ± 0.3 MPa and a temperature of around 400 degrees; the turbines shut down automatically when the exhaust pressure exceeds 0.3 MPa. Do yours shut down automatically when the pressure falls below 0.7 MPa? So what is your normal exhaust pressure?