【JST-046】Condensing steam turbine operation expert one-to-one help office
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This post was last edited by Firefly on 2015-4-10 08:34. I am a professional: I am engaged in steam turbine operation and compressor operation for many years, including one-to-two units, domestic steam turbines, man turbines, domestic compressors, and imported compressors. Online time: Online from time to time, usually offline for no more than 15 hours ； Leave a message with any questions and you will get a reply soon. Everyone is welcome to communicate with each other about steam turbine on-site operation, DCS operation, equipment structure, operation questions, simple design, control system, equipment modification, etc., aiming to improve together! Secondly, I hope that everyone will give me corresponding feedback after every answer I give, and I hope it can help you.
This post was last edited by salesment on 2012-4-9 10:27 How to test the air tightness of a two-stage steam-injection air extractor before starting it up? What is the allowable decompression rate, which means the air tightness is qualified? Don't ask me to check it myself. I asked you just because I didn't find it (for the answer, please refer to: 3rd floor)
Hello, please perform air-tight operation on the jet air extractor when it is originally driven.: Generally, only the water side air tightness is tested. For its principle and method, you can treat it as a heat exchanger to check the air tightness. The test pressure is 1.05 times the operating pressure and is tested with soapy water. If there is no bubbling, it is qualified. This is my answer to your question. For the two-stage air extractor, the heat exchanger is installed as a whole. For the water side, the pressure is maintained for 30 minutes. If the pressure does not drop, it is qualified. The hydraulic test pressure should be 1.25 times the operating pressure. If you have any questions, please let me know
Is it qualified if the pressure does not drop? There should be a blood pressure reduction rate, right? Does it stay the same for 30 minutes?
This post was last edited by yuchenchf on 2012-4-11 07:57. Please talk about the advantages and disadvantages of water injection and steam extraction. :hug: (moderator tip: Please refer to the 8th floor for the answer)
This post was last edited by lifawei109 on 2012-4-9 16:42 Regarding the air tightness inspection of the equipment, if you check it as a heat exchanger, there should be no leaks and the pressure will not drop for 30 minutes. Generally speaking, your air tightness test is completed by the staff of the installation project. The instructions have corresponding acceptance standards. We hope that they can read your equipment instructions carefully. If you lack the corresponding information, follow the relevant content in GB150 and GB50235.
You're welcome, I just hope it helps.
Features of water jet air extractor: 1. It has strong suction capacity, large safety margin and low motor power consumption. 2． Long service life and long maintenance cycle. 3． It is easy to start and does not require additional auxiliary equipment. 4． It is easy to maintain, easy to operate and has a simple structure. It can be seen that this type of air extractor is convenient for use in large units, especially large generator units, to facilitate startup and save energy during normal operation. However, it needs to be equipped with a dedicated motor and water pump. The investment cost of the water tank is relatively high and it occupies a large area. Features of jet air extractor: 1. An auxiliary air extractor is required during startup, which consumes large amounts of steam. 2. Cooling water is required and lost during the normal process. 3. The structure is complex and the operation is troublesome. 4. The installation area will be more flexible and can be easily placed according to the setting of the unit. 5. The main air extractor has high efficiency and can recover condensate, improving economic benefits. According to its characteristics, this type of air extractor is mainly used on small units. It can meet production needs with less steam consumption, save floor space, and can use low-pressure steam to meet needs. It can be seen that the slow water ejection air extractor may be more widely used, and it is possible to produce new air extractors. I hope my answer will be helpful to you.
This post was last edited by lizhenpeng on 2012-4-17 08:35. I would like to ask: Is the condensate in the second stage of the C-2620-1 two-stage steam ejection type air extractor returned to the hydrophobic expansion tank next to the condenser? (Moderator prompts: Please refer to the 10th floor for the answer)
It can be seen that it is a steam extractor: For jet air extractors, the steam condensate used in the primary and secondary air extractors of the main air extractor will enter your condenser and then be transported out by the condensate pump. The condensate returns to the hydrophobic expansion tank, and this can be returned. If you don't go back but end up in the ditch, that's okay. If you don't go back, you can go to other parts of the condenser. The main thing is to look at the configuration and design drawings of this pipe. It doesn't matter. I hope my answer can help you. Secondly, you should have some thoughts when asking this question. Why not tell me what problems you found?
The steam condensed water from the jet air extractor will return to the condenser. If it is drained into the trench, energy consumption will increase. The first stage of the return condenser is a U-shaped tube, and the second stage is a water trap to ensure that the vacuum of the condenser is not affected.