Closed Cooling Water suction pressure not stable
Closed Cooling Water suction pressure not stable
(OP)
We have a closed cooling water with a fin fan cooling assembly for our gas turbine. it is also equipped with an expansion tank. the cooling water cools the generator radiator, lube oil, turbine legs etc. during normal operation the suction and discharge pressure sometimes increases, so we decrease the pressure by draining at the generator radiator side. when the pressure decreases we top it up by opening a valve connected to the expansion tank. what is the possible causes of this fluctuations or should we modify our system's design.





RE: Closed Cooling Water suction pressure not stable
From the description it sounds like normal behaviour or maybe your expansion tank isn't big enough.
Maybe the expansion tank bladder is broken/ leaking
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Closed Cooling Water suction pressure not stable
I agree with LittleInch, that first expansion tank shall be investigated. What kind of expansion tank is it? Size, and pressures...
Kurt
RE: Closed Cooling Water suction pressure not stable
MJCronin
Sr. Process Engineer
RE: Closed Cooling Water suction pressure not stable
RE: Closed Cooling Water suction pressure not stable
During the normal operation the CCCW system the temperature of the cooling water will increase as it passes through the various cooling circuits dissipating the heat that is generated by the various processes. To allow for the expansion of the water, due to this heat pick-up and without causing a significant pressure increase, one (1) expansion tanks is installed.
The top void of the tank is filled with dry air to allow the water to expand as it enters the tank, thus stabilizing the system pressure.
To protect the system from being over pressurized, the tank incorporates a pressure relief valve.
In case of water losses in the closed cooling water system, the pressure in the tank decreases and therefore the system is refilled. For this purpose the system is fed by the Demineralised water.
Nowadays we frequently experience increased suction/discharge pressure and it mostly raptures our generator radiator.
I' am finding the PID from our database. I will post it to you if I get it.
thank you
RE: Closed Cooling Water suction pressure not stable
Does the relief valve still work?
A diagram and some more details would be nice.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Closed Cooling Water suction pressure not stable
@ LittleInch We installed new relief valve
RE: Closed Cooling Water suction pressure not stable
Still looks like your expansion tank is too small.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Closed Cooling Water suction pressure not stable
RE: Closed Cooling Water suction pressure not stable
LittleInch, liliput1
I think our cooling system needs modification. we will schedule it for our next shutdown maintenance.