I would like to ask about the steam turbines used by our company, which are from Hangzhou Steam Turbine
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The turbine control valves of Hangzhou Automobile’s engines are usually adjusted automatically based on the speed; yet now, with the steam pressure remaining constant, why does the opening degree increase from 78% to 100% and cannot be reduced?
First, check whether the instrument control system is functioning properly. Additionally, a constant pressure does not mean that it is at the pressure level you need. It is recommended to find a reference point for operation control in order to take targeted actions. Because your operating reference point is not the valve opening, but rather the steam pressure that drives the rotor, controlled according to the speed you require. The valve controls this pressure. It’s under control; there’s no problem with this valve. If it’s not under control, then it’s necessary to check whether the pressure from the gas supply unit is sufficient. Under normal conditions, if the valve opening increases from 78% to 100% without an increase in rotational speed, it indicates that the total air supply is insufficient, the valve opening does not match the actual value, and there is an error in the instrument readings.
Check whether the secondary oil pressure is normal? Is the equipment load too high?
The secondary oil is normal, the load remains unchanged; when the control valve is opened to 100%, the speed drops. The only solution is to increase the steam pressure, but once the steam pressure decreases again, the problem persists
This situation seems to be due to scaling.
If the steam inlet flow rate does not change much compared to before, it may be that the air hammer in the turbine control valve has fallen off.
Is the chamber pressure too high in round 1? 2. Has the purity of hydrogen decreased? 3. Has the back pressure increased?
1. Has there been any change in the composition of the medium? 2. The valve disc inside the speed control valve may fall off; even when the valve is fully open, the actual amount of air intake still does not meet the requirements of the current operating conditions. It was observed that there was no significant change in the steam flow rate when the valve was fully open. 3. There has been a change in the back pressure of the compressor. 4. There has been a change in the back pressure of the turbine
Check the steam consumption of the turbine compared to previous levels; the decrease in turbine efficiency can be attributed to various reasons: 1) increased pressure; 2) corrosion, damage, or scaling of the blades; 3) wear of the steam inlet nozzles and control valves.
Assuming there are no issues with the instruments, the data is accurate. A larger opening means more steam is consumed; with the load remaining unchanged, the back pressure should increase. With the back pressure and load remaining unchanged, it indicates that there is not much variation in the steam entering the unit, which means that the flow rates at 78 and 100 are similar; check the inlet nozzles. If conditions permit, appropriately reduce the steam pressure and observe the changes.
Considering the detachment of the air hammer under unchanged operating conditions, one valve failed to function properly