Chiller power saving calculation...plz help...

[coolbug]

Dear All,
I am novice in diz field, so kindly help.
I now want to calculate the power saving. The running motor with the chilled water chiller is of 125 KW capacity helping it in generating 189 TR (needed for working of 15 Clean Rooms). Now suppose that due to no orders in place at few clean rooms can be shut down , and in turn the respective AHUs inlet chilled water valve is closed. So I guess, this will ensure that the load of the Chiller is reduced by the amount of TR requirement of that AHU.
So now can u tell me how to calculate the estimated reduction in power consumption due to reduced load (caused due to closing of AHU inlet valves ).......?
In short wat is the relation between reduction in TR required and the Power consumption...? can u quantify it...??

 

[DRWeig]

It is not simple. Different chillers have different part-load performance, and it is not linear.

There should be a chart or graph of input power versus load and input power versus (inlet condensing water temperautre - chilled water supply temperature). You should find these in the data sheet for your chiller. You will also find that the power varies with condensing water temperature for a constant chilled water supply temperature, so you have to consider both factors. The regression is usually 2nd order, meaning that efficiency varies as the square of both of those factors.

Be very careful to maintain minimum chilled water flow through the machine. If every valve in the system is two-way, you might have a problem. Some sort of bypass is needed.

The method I use to calculate energy savings with two-way versus three-way valves is a simulation program like Carrier HAP, Trane Trace 700, or eQuest (free from the US DOE).



Best to you,

Goober Dave

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[willard3]

Forum policy:

>>>>These fora should not be used to bypass your own in-depth research on the issues that affect you, nor is it intended to be a substitute for appropriate professional assistance within your field or geographical region.

It sounds like someone where you work has asked you to model this and, As DRWeig points out, this is not simple. Hire an Engineer who does this to find the energy reduction. Cooling tonnage is proportional to KW.