What are the reasons for high exhaust pressure in condensing steam turbines?
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Recently, the exhaust pressure of the turbine has been high, reaching the alarm level. What causes this phenomenon?
It is necessary to check whether the cooling efficiency of the cooler has declined (due to scaling in the cooler), as well as whether the temperature and flow rate of the cooling water are normal.
This post was last edited by liaifeng on 2020-2-20 at 19:30. A check can be done for: 1. Air leakage; 2. Cooling water temperature and flow rate. 3. Hot well level (should not be too high or too low) 4. Has the unit load increased? 5. Are there any issues with the steam extraction system?
3. Hot well level (should not be too high or too low) 4. Has the unit load increased? 5. Are there any issues with the steam extraction system?
Pay attention to the heat exchanger! The area affected by scaling is large
The suggestions from the 3rd floor are being dismissed one by one! Very useful for reference!
I’m not sure if yours is of the air-extraction type or the air-condensation type; the situations are different in each case
1. Whether the seal of the rehydration system has been damaged. 2. The operating condition of the vacuum pump (steam, cooling water). 3. The quality of the steam supplied to the turbine – whether it contains too much non-condensable gas. 4. The level of liquid in the heat well. 5. The cooling efficiency of the rehydrator. 6. Excessive steam flow into the turbine. 8. Instrumentation issues
Separate inspections: 1. Cooling water system: Check whether there is a decrease in flow rate, temperature, and pressure； 2. Steam system: Whether the steam pressure meets the required standards, or whether the unit is overloaded even if the pressure is within range, exceeding the capacity of the surface cooler (this can be determined by checking the temperature of the exhaust vent line of the extractor) ； 3. Vacuum system: pump efficiency, leakage points ； 4. Is the liquid level setting for the hot water well reasonable?
1. Check whether the cooling water volume, water temperature, condenser terminal difference, and exhaust volume change, whether there is any leakage in the vacuum system, and whether the exhaust pump is operating properly