Wire-to-Water Efficiency of Pumping Systems
Wire-to-Water Efficiency of Pumping Systems
(OP)
Greetings
Can anyone tell me how equation (2) was derived in the following article? The equation is regarding the wire-to-water efficiency of a multiple pump, constant speed pumping system. I am not sure how the pressure-head ratio fits in. The product of the pump and motor efficiency is obvious.
bookstore.ashrae.biz/journal/download.php?file=Rishel.pdf
The article is from the ASHRAE Journal so the application is for hot and chilled water circuits.
Thank you
Can anyone tell me how equation (2) was derived in the following article? The equation is regarding the wire-to-water efficiency of a multiple pump, constant speed pumping system. I am not sure how the pressure-head ratio fits in. The product of the pump and motor efficiency is obvious.
bookstore.ashrae.biz/journal/download.php?file=Rishel.pdf
The article is from the ASHRAE Journal so the application is for hot and chilled water circuits.
Thank you





RE: Wire-to-Water Efficiency of Pumping Systems
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Wire-to-Water Efficiency of Pumping Systems
In the real world, the pump fitting and pump header friction losses should be a small fraction of the total pumping friction loss anyway, so it probably does not matter.
RE: Wire-to-Water Efficiency of Pumping Systems
pump, constant speed pumping system
is:
WWE = ( Hs - Hpf ) / Hs x Em x Ep
Hs = Total friction loss of the water system
in feet of head
Hpf = Friction loss in feet of head of the
pump fittings including strainers, check
valve, shut-off valves, and the header
losses that direct the flow into and from
each pump.
Em = Motor Efficiency as a fraction
Ep = Pump Efficiency as a fraction
RE: Wire-to-Water Efficiency of Pumping Systems
The formula was copied incorrectly. It should read:
WWE = (( Hs - Hpf ) / Hs) x Em x Ep