How to match two different chilled water systems?

[ksm]

Hi,

I'd like to know that is it possible to match two different chilled water systems?
One is constant flow Carrier chilled water system and another one is variable flow Trane chilled water system.
Between these two systems,there's one chilled water cross over valve and if open that valve,carrier chiller is always tripped on compressor surge.

Please help!:)

[goshen]

:pHi
if you have a diagram of the hydrolic sys ,it could be a good start,
off hand ,a 2 loop system could be the answer ,or fitting the carrier water pump ,with a vsd and pressure diferrntial sensor ,to keep the flow constant,on the evaporator,
please send more info if you are intrested.
good luck

[ksm]

Thanks Goshen,i do not have hydronic diagram and do not have competant engineer for chilled water systems in our facilities team also.
So,please help me to explain what 2 loop system means.? Is it primary/secondary system.?
After we install VSD and PDS for carrier chilled water loop,if we open cross over valve,Can vsd control the pump speed and maintain constant flow at Evaporator if too much pressure or flow drop.?

Thanks and regards,

[goshen]

Hi ksm
yes i did mean primary and secondary loops,but with out looking at the system plan all i suggest is only a recomandation,installing a vsd and pds ,on each unit could indeed help and will maintain correct flow and pressure drop you need ,but your crossover valve must be pds controlled !!also.
that is if your crossover valve is your valve that connects supply and return for correct pressure in the main sys!
good luck

[Tesla]

Hi ksm
It is likely to be a Tracer Trane controller for secondry loop. The cross over (bypass) valve should be controlled by the Tracer. If this valve is open it is because the secondry loop has reached setpoint. Surge could be due to a refrigeration fault on the chiller. It could be due to control of when the chiller is called on and how long it takes to stage down - normally a centrif is for steady base load with other chillers doing low load conditions. Do you know the history of this job?

[ksm]

Dear Goshen and Tesla,
Let me explain about our system,Carrier chiller plant is supporting to load A and Trane chiller plant is supporting to load B.Now what we are trying to do is open the chilled water cross over valve between two chiller plants and to achieve both chiller plants are support to Load A&B together.
Cross over valve what i mean is the connection valve between these two different chilled water systems.
Its not the chilled water bypass valve for individual system.
Sorry for didnt mention earlier.
Thanks.

[goshen]

Hi
do you have 2 seperate expansion tanks??

[ksm]

Yes,Goshen.We have 2 seperate ex tanks.

[goshen]

Hi
in that case you first have to match sys working pressures.
when that is achieved ,their should be no problem working with both chillers in paralel,but you will need to use a dps and a vsd for the cold water pumps.
we have done something similar before and it did work . if you have a bms sys life will be a lot easier.
let me know how it worked out
good luck

[ksm]

Thanks a lot.