Location of Steam Boiler Feed Pump

[kotsis2000]

Hello all,
I am trying to locate a boiler feed pump that will be serving two steam boilers at 114 Bhp each. Is there any guidelines of how far the pump can be located from the boilers. The condensate is gravity fed, and i want to located the boiler feed pumps two floors below the boilers and about 100 feet away. Is there a min or max distance guideline?
Thanks for your advise and replies.

 

[racookpe1978]

Real world guidelines - from being inside many dozens of plants that I can omly assume were "optimized" for economy and ease of design (because they were sure as h*ll not optimized for repair and replacement!) comes from the following:

Your condensate pump(s) are very limited by location (NPSH requirements) to the very bottom of the condenser, very close to the condenser. Their output is the feed water to the feed pump.

OK, so the condensate output piping pressure is high volume, but (relatively) low pressure. Figure relatively low cost per length. Low erosion. Cheap to run a long ways.

Intermediate heat exchangers or cross-connect pipes between the condensate pump and feed pump? You need to get piping to and from those heaters, regardless of where the feed pump is.

The turbine feed MUST have good crane access up to the turbine deck and to the trucks/trains simply and easily - or you need to build some other way to move parts and pieces into and out of the pump during your outages! If you don't do this - your maintenance gets REALLLLLL expensive real quick since your outages are delayed waiting to build the feed pump.

The input to the feed pump is either steam or large power circuits/breakers and large cable runs. NEVER - NEVER put a cable run over the turbine or motor!!!!!!

If steam, plan a run for that, plus the control hydraulics (?) and control oil. If electric, AGAIN!!!!! - plan on a way to lift out and replace that motor. Almost all turbine pumps I've seen have been on the plant floor, but a few are up on the turbine deck. Either works, its easier to repair pumps up on the deck than wedged down below on the plant floor. Needs bit more structural support for the deck though.

The output piping from the feed pump is high pressure, high expense per length. Put the feed pump as close as practical to the boiler inlet to reduce runs. Piping flow loss? try to minimize by using as big a pipe as you can get away with - expect your plant pump requirements to grow if the turbine is rebladed and the plant is more efficient.

 

[Pumpsonly]

raccokpe1978 has give a very good lesson on power plant design layout.

If the OP's concern is about the operation of the feed pump only. there is no concern as long as the pump get sufficient NPSHA from the condensate feed drum and the pump still have enough pressure to feed the boilers after the piping losses in the long discharge piping.