【Daily Question No. 308】November 10, 2018
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【Daily Question No. 308】November 10, 2018: Briefly describe the possible reasons for water content in turbine lubricating oil ((1) Cooling*unit* leakage ； (2) As the vacuum level decreases due to pumping out air and sealing issues, steam leaks from the shaft seal of the turbine and mixes into the lubricating oil ； (3) High air humidity. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) Correct: 3 wealth, Incorrect: 1 wealth ； Mass posting of posts – rated based on the lowest score ； Replies that are unrelated to the answer are considered spam and will be deleted immediately. For management purposes, if you need to view content from a few days ago, please go to https://bbs.hcbbs.com/home.php?mod=space&uid=3862647&do=thread&view=me&from=space through the summary post below
The function of the high-pressure cylinder shaft seal (end seal) is to prevent steam from leaking along the rotor. The configuration of the shaft seal system is not very reasonable. The fact that the steam supplies for the high and low pressure shaft seals are connected to the same main pipe causes uneven distribution of the steam supply. Controlling the steam leakage from the second chamber of the front shaft seal in the high-pressure cylinder is key to preventing shaft seal leakage. Tests have shown that if the pressure of steam leakage from this chamber is increased to above 0.014 MPa, significant leakage will occur at the shaft seal. Therefore, while maintaining the vacuum in the unit, the steam leakage pressure at the second stage should be kept as low as possible to prevent water from entering the oil. Water in the oil is mainly caused by steam mixing into the oil system, but it is not necessarily just steam leaking from the shaft seals; it could also be steam leaking from the joint surfaces of the cylinder block near the bearings. The joint surfaces include: high-pressure cylinder joint surface, shaft seal sleeve joint surface
1. Oil cooler leakage. 2. The steam shaft seal exhaust pipes at both ends of the turbine are blocked. 3. The radial clearance of the shaft seal is adjusted too much. 4. Internal leakage in the shut-off valve during unit shutdown.
The function of the high-pressure cylinder shaft seal (end seal) is to prevent steam from leaking along the rotor. The configuration of the shaft seal system is not very reasonable. The fact that the steam supplies for the high and low pressure shaft seals are connected to the same main pipe causes uneven distribution of the steam supply. Controlling the steam leakage from the second chamber of the front shaft seal in the high-pressure cylinder is key to preventing shaft seal leakage. Tests have shown that if the pressure of steam leakage from this chamber is increased to above 0.014 MPa, significant leakage will occur at the shaft seal. Therefore, while maintaining the vacuum in the unit, the steam leakage pressure at the second stage should be kept as low as possible to prevent water from entering the oil. Water in the oil is mainly caused by steam mixing into the oil system, but it is not necessarily just steam leaking from the shaft seals; it could also be steam leaking from the joint surfaces of the cylinder block near the bearings. The joint surfaces include: high-pressure cylinder joint surface, shaft seal sleeve joint surface
1. Steam leakage from the high-pressure shaft seal enters the bearing box. 2. Condensate from the exhaust fan in the oil tank flows back. 3. Water forms at the leak point of the low-pressure shaft seal and is drawn into the bearing box. 4. The online centrifugal oil filter is not effective
1. Steam leaking from the steam seal enters the bearing box and then makes its way into the oil tank. 2. Water leaking from the oil cooler enters the lubricating oil circuit. 3. Due to humid air and large temperature differences, water vapor from the air enters the oil tank
1. Steam leakage from the high-pressure shaft seal enters the bearing box. 2. Condensate from the exhaust fan in the oil tank flows back. 3. Water forms at the leakage point of the low-pressure shaft seal and is drawn into the bearing box. 4. The online centrifugal oil filter is not effective; the shaft seal can be improved by replacing it with a side-tooth steam seal, and the parameters of the steam supplied to the shaft seal can also be adjusted accordingly. Improving the performance of the oil filter and optimizing the layout of the pipelines can help resolve these issues.
There are no turbines in the workshop; learn about them.
(1) The shaft seal gap is too large or the steam pressure is too high. (2) The cooling water pressure of the oil cooler is higher than the oil pressure, and the oil cooler is leaking. (3) After the oil system was shut down, the cold oil cooler leaked, causing cooling water to leak into the oil side. (4) The fuel tank exhaust fan failed, failing to remove the water vapor from the fuel tank in a timely manner.
1. Steam leaking from the steam seal enters the bearing box and then makes its way into the oil tank. 2. Water leaking from the oil cooler enters the lubricating oil circuit. 3. Due to humid air and large temperature differences, water vapor from the air enters the oil tank