Questions regarding the setting of pump simulation power and efficiency
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What does an adiabatic efficiency of 75% mean in the parameter settings of the pump in this instance? When is the adiabatic efficiency used, and when is the polytropic power used in practical applications? If the pump’s rated power is 250 hp and it operates at 90% of that rated power, how should it be set? This post was last edited by visavis on 2009-1-20 11:12.]
A very interesting topic; welcome to discuss it
Adiabatic power is used during adiabatic operations, isothermal power is used during isothermal operations, and the polytropic efficiency is used in cases that are neither isothermal nor adiabatic. Choose based on the operating conditions of your pump.
But how is the rated power set? It seems there’s no direct setting option for it; does it need to be converted into other variables in order to be set?
I think if I figure out what “calibrated power” means, I’ll understand what’s going on; the issue is that I don’t understand how the software does the calculations and what results it produces.
I understand that pumping a liquid phase can basically be considered an adiabatic process, right? Except for those with very low traffic. Furthermore, whether insulation is applied during liquid phase transport has little impact on the pump’s power consumption; in my humble opinion, more discussion is needed on this topic.
But in the example, the pump is required to operate at 70% of its rated power of 250 hp. Should the setting be made directly in terms of power, or should it be converted into other parameters? It seems like I don’t see a field where I can set the power directly?
I think it’s very likely to be a textual issue rather than a technical one; it might also be due to different settings associated with various software versions. The original poster had better bring up the question directly and show it to everyone.
Given the characteristic curve of the pump and the known inlet flow rate, it is possible to calculate the pump’s efficiency and outlet pressure. Pumps generally refer to adiabatic efficiency, while compressors have a variable efficiency setting.
I wonder what software you used to simulate it. Taking PRO/II as an example: Pump efficiency is the ratio of the power delivered by the pump to the total power input to the pump. Under ideal conditions of frictionless flow, the efficiency of a pump is 100%. Actual pumps, due to friction and other factors that deviate from perfection, fall far short of this ideal value. This definition is consistent with that in principles of chemical engineering; if anything is unclear, refer to those principles. There is no issue of pump adiabatic efficiency in PRO/II, nor is this term used in the principles of chemical engineering. Adiabatic efficiency is a term used for compressors; for a detailed understanding, it is recommended to consult chemical thermodynamics.