Minimum pressure issue of reciprocating machines
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Some books or guidelines state that there is a minimum pressure limit at the inlet of reciprocating machines! So what’s the deal with the limit on the inlet pressure of the recirculation compressor? Why? Are there any regulations? Isn’t the back pressure of a circulation pump just the pipe pressure drop plus the inlet pressure?
The inlet pressure limit of a reciprocating compressor stems from the principles underlying its mechanical design; just like an injection syringe, what would happen if an infinitely strong force were used to pull the plunger with a sealed needle in place? Since the power source of the compressor is designed to operate within normal parameters, if a certain negative pressure occurs at the inlet, it will inevitably lead to insufficient power supply and damage to the equipment. Additionally, the “circulation machine” you mentioned can be any power mechanism capable of circulating a fluid. It has no necessary connection with the former. Please rephrase the question from a new perspective. It is recommended to understand the principles of relevant types of compression machinery; those that are not clear should be shared for discussion.
Inlet pressure limitation is a constraint on mechanical equipment; during the operation of reciprocating machines or when they are started up, if the inlet pressure is too low and the flow rate is insufficient, this can result in vibrations in the inlet pipeline, or in the worst case, the pipeline may collapse, leading to damage to the equipment.
Why is there a limit on the inlet pressure for reciprocating machines that perform cyclic work? As long as it’s not zero, that’s fine! What is the minimum limit?
What is a “reciprocating compressor”? “Why is there a limit on the inlet pressure for reciprocating machines that perform cyclic work? As long as it’s not zero, that’s fine! What is the minimum limit? ”Why do you think so! Then try adding a blind flange to the compressor inlet! Why? I’m trying to reason with you kindly, but you just say, “As long as it’s not zero, that’s fine!” ”Your question doesn’t say it’s not zero either! If you want the outlet to reach the designed pressure, it follows the parameters specified by the manufacturer in the original design – so why change it? When discussing issues, one should be rational.
You didn’t understand. For example, the pressure in the jet fuel hydrogenation system is currently 1.5; if there is a sudden pressure drop to 0.5, the pressure difference across the reciprocating machine remains high, and it still operates properly!
I mean there’s a pressure limit inside this. As for how to interpret this value, I certainly know that the pressure ratio can’t be high; it’s not a reciprocating compressor used in system circulation
Oh, if you had made it clear earlier, that would have been fine. The phenomenon can be explained by the cyclic effect. ““The pressure ratio before and after the reciprocating machine is not very high either”; in fact, it does change, and it depends on whether the air supply unit has reduced its load as well as on what caused the sudden pressure drop. If your equipment has trend lines that can be used for analysis, it is likely that the automatic activation of the circulation valve is the cause; in such cases, the pressure at the compressor inlet will increase. It is recommended to check the trend charts of the gas supply unit and the downstream units as well. Sometimes, explaining a problem requires looking at it from multiple perspectives.
Thank you! It doesn’t matter if you ask me why a minimum system pressure needs to be controlled! For example, the technical competition simulations for some devices require that the system pressure at certain shutdown points must not fall below a certain level, and this is also related to this issue! I think it’s still related to the minimum pressure of the exhaust valve, but it isn’t mentioned in 618. . .
When faced with training exercises, first of all, it’s impossible to score full marks; otherwise, how is that possible when those who work in technical fields aren’t as skilled as you? Also, for many technical issues, the answers are also subject to discussion. \"Principles of Chemical Engineering\" and \"Chemical Engineering Machinery\" are fundamental books for those working in this industry, and both are easy to understand. It can handle most of the questions related to interpretation roles.