Cool water for condenser with waste energy

[siggihm]

I have a cooling system in a power plant that operates on water based cooling tower. The inlet temperature into the condenser is around 20c. I have a lot of waste heat and low pressure steam. I would like to use the thermal energy to chill the water down few degrees.
The cooling system mass flow is around 3 m3/s.

Possible?

 

[GHartmann]

Firstly you already have extremely cold cooling water temperatures into your condenser. In the USA, Gulf-Coast area one would expect evaporative cooling tower exit temperatures of 30 to 33 deg C. You can try an absorption type refrigeration unit. However, you will need to check your own energy balance as the "energy" from the steam and "extracted" from the cold water must now be taken up by your cooling water system. It almost seems as there will be a net loss there; but you will need to check your own energy balance.

Good luck.

Gerry Hartmann
BS ChE NCSU

 

[StoneCold]

One way that you could use steam to cool the cooling water would be to pull vacuum on the water with an ejector.
It would take a tank and some careful level control but you could vaporize some water off your cooling water and make it a little cooler.
However with 20C cooling water I would not bother.

Probably a better way to use the heat would be an ammonia boiler to generate some power????

Regards
StoneCold

 

[MJCronin]

It sounds like you might have the wrong kind of steam turbine for your plant's needs.

Are you operating a steam turbine in a variable extraction configuration ?

http://books.google.com/books?id=hA...q=variable extraction "steam turbine"&f=false

Or is this an older non-extraction steam turbine that was re-used from some other service ?

What is the range of "waste heat" that you are trying to harvest as compared to main steam flow ?

MJCronin
Sr. Process Engineer