Submersible pump heat gain

[DeltaH]

Looking for a rule of thumb to estimate heat gained from a submersible pump in a temperature sensitive aquatic system. Have a 17.6 KW pump sized @ 75% efficiency, what precentage of wasted energy can I assume or calculate will be transmitted to the water system as heat?

DeltaHydro

 

[hydtools]

25% ? The inefficiency.

Ted

 

[DeltaH]

That is what I assumed, the obvious. I guess any sound power and vibration energies would be transmitted into the submerged water environment too oppossed to a dry mounted pump installation. So I'll assmue all wasted energy ~ 25% THANKS

DeltaHydro

 

[hydtools]

That would be worst case. Some heat will be removed by product that leaves the system.

Ted

 

[DeltaH]

THANKS hydrotools

All water is recirculated within the system, and will be subject to ambient conductive and convection surface area losses which I need to calculate.

DeltaHydro

 

[badservo]

hydtools answered your question correctly, but you only asked about the wasted energy, where is the other 75% going?

 

[BigInch]

Maybe .. increasing the water pressure.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[Bribyk]

I think badservo's hinting that, if it's a recirculating system, isn't 100% of the input energy going into the water?

 

[hydtools]

If the pump is recirculating, all the energy goes into the system and you are not dealing with only the inefficiency.

Ted

 

[unclesyd]

Looking at BigInch's tag line what % of the input is the motor given up as heat, etc.?

 

[IRstuff]

Sure, the VitaMix can just about boil water just from the churning of its blades, so ALL of the power consumption would go into the water, either kinetic energy or as heat.

TTFN

FAQ731-376

 

[BigInch]

Assuming a closed hydraulic system, he's only losing energy by evaporation from the surface of the aquarium and conduction through the floor and walls, which is probably a considerable amount, but he needs to calculate the possible minimum and maximum stabilization temperatures.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/