Energy saving in Chilled water system

[psrao]

Hello friends,
We have chilled water system having hot and cold well. The return line is coming from a height of 30 mtrs. It looses its return head pressure (around 3 bar) in Hot well. Again secondary pumps have to pump from 0 bar to 5 bar in the supply header consuming much energy. As a energy conservation project, whether the chilled water system can be modified to closed loop to get the benefit of return water head pressure. Really will be there any energy saving. The water flow rate through chilled water system is around 600kl/hr.

[The Viking]

Just trying to picture this in my head before I give a stupid reply (as I normally do).

The pumps are pumping from a well, up the building? What's happens to the water next?

What's the height difference between the inlet and the outlet pipes?

[Brian_UK]

Viking, I think he is referring to having an open tank of some sort where the process water, having done it's cooling job returns to a tank.

The 'hot' water is then pumped around the evaporator circuit and into the 'cold' side of the tank where it is then sucked up by the process pump and round it goes again.

Mind you, I could be wrong - it's not unknown.

[The Viking]

Brian, I thought of something similar....

The point being that if I'm right then the height difference doesn't matter, as the weight of the water "coming down" will pull the same mass of water up. (as long as it's a sealed system at the higher level).
The only time the pump has to "lift" the full mass of water 30 m up is on initial fill.

But I might have gotten the wrong picture of the system.

[Josip]

Hi, psrao :)


Hello friends,
We have chilled water system having hot and cold well. The return line is coming from a height of 30 mtrs. It looses its return head pressure (around 3 bar) in Hot well. Again secondary pumps have to pump from 0 bar to 5 bar in the supply header consuming much energy. As a energy conservation project, whether the chilled water system can be modified to closed loop to get the benefit of return water head pressure. Really will be there any energy saving. The water flow rate through chilled water system is around 600kl/hr.

Is it possible to post some scheme about your plant/project...we are engineers here and it is much better to see what we are talking about..;)

Best regards, Josip :)

[psrao]

Yes Mr. Brian u r correct. The system is having open hot and cold well tank. My point is that If the tanks are bypassed and system made to a closed circuit, will it be helpful in energy conservation

With Regards,
P S Rao