Regarding the problems on the steam turbine exhaust pipeline, please give me some advice.
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The hand-drawn diagram is not standardized. Please forgive me. The exhaust steam from the steam turbine goes to the air-cooling island, condenses into water, and then enters the condensate tank and is transported by the pump. However, there is a pipeline that I don’t understand clearly. It is a pipeline from the exhaust pipeline from the turbine to the air cooler to the condensate tank. I don’t know what the purpose is? ? ? What is its main function? Please help me explain
The pictures are really bad, haha! But I can understand what's going on, and that's enough! Let’s push forward the function of this pipeline bit by bit.: 1. Air cooling is a cooler, where the change process from gas phase to liquid phase occurs. I ask you, does the volume change? What about pressure? Give me a chestnut: When 1 cubic meter of water turns into 1.0Mp steam, the volume is roughly 1300m³. Then in the opposite condensation process, the volume changes from 1300m³ to 1m³. How will the pressure change? 2. In a fixed pipeline container, if the situation mentioned in the chestnut occurs, the pressure will inevitably show negative pressure. At this time, the pump will not pump enough due to the negative pressure. How do you solve the problem? 3. Raising the height of the tank to increase the inlet pressure is one way, but it is not the most economical way. The pipeline you mentioned is the true meaning of cracking. It is simple and crude. I like it. I won’t tell you what it does. I’ll try to understand it myself and hope to make some progress!
This answer is concise and to the point, I like it
It is better to teach a man to fish than to teach him to fish. I like this answer.
Following the second point you mentioned, the designed inlet pressure of the condensate pump is -80kpa. If there is a certain stable liquid level, the pump will not be able to pump enough, right? In addition, the addition of this pipeline will undoubtedly increase the working capacity of the air extractor, right? ?
Your steam turbine is of the condensing type and requires a guaranteed exhaust pressure (a certain degree of vacuum) to ensure the operation of the unit. In fact, the first explanation I originally typed was: 1. What would be the impact if there was no such pipeline? Whichever is the lesser of two evils. Is it more important to increase energy consumption here to ensure stable operation of the system, or is it more important to reduce energy consumption. Moreover, such pipelines are generally equipped with flow-limiting orifice plates, and the second point is a throttling valve. The vacuum degree is too high, the amount is basically not enough, the liquid level increases, the vacuum degree is destroyed, and the machine shuts down! If the vacuum degree is too low, it will directly affect the operation of the unit, and it will have to shut down if it fails. This type of pipeline, technically called a pressure balance line or pressure compensation line, is used in many places, but its functions are basically similar.
Can this pipeline be regarded as a jet air extractor to maintain the vacuum?
This post was last edited by symc on 2020-5-8 11:20 The explanation above is not appropriate, but the name is correct. It is indeed a pressure balance tube. Its function is very simple - to balance the pressure between the front and rear parts when draining... draining... the liquid! ! ! What will happen if you fill a bottle with water and pour the water vertically out? The principles are the same! Just like the picture you drew, there must be a curve at the top that goes up and then down... to prevent liquid from entering.……
Thanks for the correction. Perhaps your explanation is more straightforward and may also involve other derivative effects in actual application! Different paths lead to the same goal, and I have learned a more direct confession from you. Thank you again!