trane chiller flow

[ff93]

i would like to determine flow of the water through the chiller. I know the pressures on the incoming and outgoing sides - can i determine flow from this pressure difference? and if so, how?

regularly get compressors locking out "low pressure control open" and "evap flow proving switch"

am told that there is a water flow problem causing this, and i would like to confirm or deny.

[Sledge]

I think the only option, would be a flow meter.

[lana]

Hi there,

You can estimate the chiller water flow like this :

1- Measure water inlet and outlet temperatures. (ti , to)
2- Measure suction and discharge pressures and from the refrigerant pressure-temperature chart find the corresponding temperatures which are evaporating and condensing temperatures (te , tc).
3- Go to your compressor catalog and find the capacity at the operating conditions.
4- use this formula Qe= m x Cp X TD

Qe = compressor capacity (kW)
m = chiller water flow in (kg/s)
Cp = water heat capacity (4.18 kJ/kg.°K)
TD = ti - to

When you find the water mass flow rate in (kg/s) then you can convert it to volume flow rate (m³/s).

Volume flow rate = mass flow rate x density

Hope this helps.
Cheers

[coolsaj]

i would like to determine flow of the water through the chiller. I know the pressures on the incoming and outgoing sides - can i determine flow from this pressure difference? and if so, how?

regularly get compressors locking out "low pressure control open" and "evap flow proving switch"

am told that there is a water flow problem causing this, and i would like to confirm or deny.

there must be a manual or a log book to determine pd across the evap. check your deltap to determine delta -t it is most important check stat it appears you are losing water pressure.

[marley821]

Access to information can sometimes be difficult to determine, ie design data etc.

One easy way of determining water flow rate through a chiller would be to run it on full load and check the evap td, ie difference between inlet and outlet temps.

The design td for most chillers is around 6 deg, ie 12deg inlet temp, and 6deg outlet temp.

A td above 6deg = low flow rate, if its as low as it looks from your thread you should notice fairly quickly.

A td below 6deg = highher flow rate than design.

Also, chiller may be tripping on antifreeze if flow rate is low through the chiller.

Good luck!!!

[ff93]

thanks for the answers!

I am not a techie, but I will try to find out / figure out according to your suggestions... i will let you know in the next day or two what I can find out.

incidently, the thing locked out today... again.

[Lowrider]

Normally a valve would be installed in either inlet or outlet, where one can measure flow, for instance a TA valve or one of oventrop.

Check with the company who did the installation and have them measure the flow over the evaporator.

Also check and see if there's enough water/ brine in the installation and no air!

[borodave1973]

Have you checked the water filter and anti freeze concentration i normally find a clean of the filter sorts out any flow probs

[absrbrtek]

Trane has published data on pressure drop vs gpm. You just need a model number for the chiller.