Thread: Pumps and heat
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Unread 07-15-2002, 12:30 PM   #44
bigben2k
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Join Date: May 2002
Location: Texas, U.S.A.
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Quote:
Originally posted by Skulemate
Bigben, I think you misunderstood. I said that the only thing you need to measure is flow rate if you have a good Q-H curve for your pump. If that's the case, you can read pressure drop (in terms of psi or feet) directly from your graph for the measured flow rate, and you have all the terms required for the calculation.
Yes, that's correct, so you were right.

As for the energy otherwise, it appears in the system in the form of pressure (and that's the answer to myv65). If you take a balloon for example, there is work being done, in every direction, so you don't see anything move, but the work is there.

In our case, our rigs have different pressure points, and that's the "mechanical" energy that the pump provides, with about 70% of the power it is provided with. Everything else (30%) is attributed to (not necessarily in order):
1-EMI
2-Heat
3-Noise
4-Friction (of water against water, water against inner surface, impeller against bearing, impeller against water, etc...)

When the pump is turned off, the pressure drops, and that's the energy that is released.
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