Selection of an Engine Driven Pump for Chilled water Application

An engine for 300kW @ 1160 rpm, with a governor, shouldn't be hard to find. The pump coupled to it would be the same as existing.

Alternatives are possible at 1800 rpm, or even higher, and would probably be more economical.

Why is the head so high?

Several questions need to be considered.

Is the electric pump existing or just the spec? Is the spec mandatory? Higher speed might be more economical (though it's a fairly hefty pump).

Is the engine driven pump in addition (standby) to the electric pump or instead of? If instead of you could choose a pump at higher speed, which would likely be more economical for pump and engine. Need to discuss with both suppliers to optimise. If pump is in addition same thing applies, unless there is a requirement for identical pumps. If the 1160 RPM is mandatory higher engine speed with V-drive (or gearbox etc) might be the way to go.

How is the electric pump controlled? Does it run at fixed speed, with flow control (if any) via throttling valves, or variable speed? If fixed speed you could just start the engine and raise the speed till flow is right, and leave the speed control there. There might be some variation in speed as the system throttling varies, causing change in absorbed power, but likely to be minimal.

If the electric pump is variable speed it depends on what basis, and you need to consider how the speed control signal is input to the engine controls.

If the engine drive pump idea is for backup it the power fails, why not just get a back up Deisel generator that can run the existing electric motor for the pump?

Use a clutch and coupling from the engine to the electric pump. You would be using only one pump with two means of driving it. If you use a second pump, you will have to provide additional valves and piping, adding up to higher cost.

Hi srgovind,

IF you must use a engine driven pump, Look at a fire pump --Clark is one US brand I am familiar with--they are auto start on loss of pressure and could be readily coupled in to a system-- or as someone said use a back up genset and transfer switch with which would also keep your BOP running.

I would suggest you size the generator not only for your pump but also for your other electrical loads such as lighting, air conditioning, and other significant loads. It would be very hard to do maintenance and trouble shooting when there is a power failure. You also need to install Automatic Transfer Switch. You use the same pump and motor without providing additional piping.

How do you run the chillers during a blackout? The pump is small potatoes.

Thank you all for reply concerning the case of engine driven chilled water pump which is critical to any District Cooling Plant to keep circulating Chilled water from thermal storage tank even if chillers trip out. Suggestions like website information, Clutch-motor-engine type, fire-application pumps, variable speed application, Use of Generator on Black-out instead of engine pump etc.