Checking Water Flow Rates though a Chiller

[Dossat]

Hi All

I need to check if I have the correct water flow rate through a chiller.
I have a 'binder' point on the flow pipework & return pipework from the chiller so I can put a pressure gauge on each and get a pressure drop through the chiller.
I know what the pressure drop should be through the chiller at the correct water flow rate.
So is this the correct or best way of determining the flow rate through the chiller or have I got it wrong. Any help advice would be appreciated

Thanks

[Gibbo]

Thats correct

[sedgy]

hi dossat,
there is a way of telling the flow rate psi x diameter? hey remind me , you guys sedgy

[frank]

You can use the good old fashioned Q = m c dt

If you know the chiller duty just use Q/(4.18x(t1-t2))

[al]

York used to print a flow rate/pressure drop graph with the chillers and then tell you not to use it!! I believe you can also use the crane balancing valves if you have access to the balancing tool.

al

[Grizzly]

Hi Dossat,
How about if you know the required pressure drop.

Load your chiller up fully and then see if you can trim the flow with the water off regulating valve.

Until you get the desired pressure drop.
On most chillers the >t across the evap would be in low single figures fully loaded.

If you are achieving 4/5 c with say 1 of 2 comps running you have a poor flow.

As a rule of thumb I multiply the PSI reading by 7 to get the kpa figure. 30 to 70 kpa diff would usually be acceptable.
When you start getting into the realms of 2/3 psi diff you have a problem.
I am just generalizing of course and most manufacturers give you tables to calculate flow and >P in their manuals.
Grizzly

[Brian_UK]

All of the above are good but bear in mind that any fouling of the evaporator will make pressure readings unreliable when compared to the flow rate.