Turbine shaft seal leakage
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There is a leak in the turbine shaft seal; previously, steam was leaking out, but now the steam from the seal is no longer leaking outward – instead, air is leaking in. Are there any good solutions? Carbon ring seal. Is increasing the steam supply to the shaft seal useful? There is an axis seal steam extraction valve; by turning on this valve, can it be used to remove the air that has leaked in? The vacuum level is currently low. reward_7ree
Air leaking in indicates that your negative pressure suction or the gap is too large; further adjustment is needed
Increasing the shaft seal size should help. Has the vacuum level been affected?
1. Excessive negative pressure; reduce the amount of steam used for extraction. 2. Insufficient supply of steam for shaft sealing. 3. Large clearance in the shaft seal comb teeth, resulting in high extraction force. I’d like to ask as well what negative effects drawing air into the turbine can have on it. Thank you
I didn’t read the question carefully; if the exhaust pressure is too high, you can try using another valve to vent it
You must be referring to a condensing steam turbine, right? Your current operating conditions are quite dangerous; you should increase the steam seal pressure and activate both sets of air extractors to remove air and restore a vacuum level.
Steam leaking in from the shaft end indicates that there is insufficient steam supply to the shaft seal, which will definitely affect the vacuum level! ! The amount of steam supplied to the shaft seal can be increased to raise the vacuum level!
In condensing-type turbines, the extraction pump should always be in operation to maintain the vacuum level. The shaft seal steam flow should be adjusted so that a slight amount of steam escapes from the exhaust pipe, with no steam leaking out at the shaft ends. If this condition cannot be achieved, there may be a problem with the shaft seal, or the gap between its components might be too large.
When air gets in, the amount of non-condensable gases increases, which affects the vacuum. The presence of water, oxygen, and iron leads to rusting.