Pump outlet pressure
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This post was last edited by 1016006686 on 2020-3-18 at 16:15. I would like to ask: in a closed-loop system, if a pump with too high a head is selected, resulting in high outlet pressure, will this affect the pressure within the closed system? The head of the pump is supposed to be used to overcome the resistance in the pipes; but if the head is too high, will it increase the pressure of the system itself, in the absence of a pressure relief valve? . . . .
The design institute advises you: For a completely sealed system, that is indeed the case. In simple terms, pressure builds up as it cannot escape; in a completely sealed system with no leaks, the pressure at the outlet gradually spreads to the inlet, causing the inlet pressure to rise, which in turn leads to an even higher outlet pressure. Until a place can no longer withstand the pressure and releases it. I’m talking about a completely sealed system.
What you say makes sense; it would probably be better if a buffer tank were added
I don’t know how this “closed-loop system” functions, nor what type of pump it is. If it is a centrifugal pump, a circulation from outlet to inlet. That is, as the suction pressure increases relatively, the outlet pressure rises and the flow rate increases. It is an abnormal form of operation; over time, it causes the medium to heat up and the pump body to warm as well. . . . . . The same result is obtained for positive-displacement types as well. The difference is that in positive-displacement pumps, when the outlet flow rate is zero, the pressure continues to rise, until overcurrent protection is triggered or leakage occurs. In the case of a centrifugal pump, when the flow rate is zero, the pressure reaches roughly the rated design value (or slightly higher) and does not increase any further. But over time, it can also cause the temperature to rise. It is best to include a schematic diagram when discussing such issues for reference.
It depends on what kind of closed system and what medium is used. Are you referring to a closed refrigeration system?
A refrigeration system is a typical closed system
(If it is a centrifugal pump, circulation from outlet to inlet.) That is, as the suction pressure increases relatively, the outlet pressure rises and the flow rate increases. It is an abnormal form of operation; over time, it causes the medium to heat up and the pump body to warm as well. . . . . . ) It means that if the pump’s head is greater than that of the pipe network, is the excess head equal to the increase in inlet pressure? Import pressure is increasing, and exports are also increasing – why then does the flow rate increase as well? I just posted a question for advice; please take a look at it :handshake
The pump inlet should have a buffer pressure stabilizing tank!