Size of Evaporator stub-outs vs. Condenser stub-outs of Cetrifugal Chillers

[ewokxz]

Hi, I'm basically new to this although i have the background in AC piping installation for i am in the field of construction.

I just wanted to ask this.

Is it normal to have the condenser outlet/inlet stub-out sizes smaller than that of the evaporator in a centrifugal chiller or for any chillers for that matter?

its just that i think its odd (or my logic is bad) that the cooling water which goes through the Condenser will be smaller in volume compared to that of the chilled water that serves the FCU's passing through the Evaporator.
I mean, will heat transfer be enough between this two (via the refrigerant) to "cool" the chilled water supply or the condenser return (outlet supply to the CT) water be heated near its boiling point so to serve the cooling required for the CHW? (just mumbling here)

My unit in question is a YORK 76.6 RT with the condenser pipe size inlet/outlet at 4" dia. and the evaporator stub-outs at 6"dia.

I did not include the technical data since I'm just asking out of curiosity with this. ;)

[surajabdan]

I have made Chiller unit of 3TR capacity, in which i have optimized the length of the evaporator coil which is direct expansion type. After taking trial run of that, i have found that there is frosting over the compressor..!! Can anyone help me in this regard..?

[MilosBog]

Hi there,
it is quite OK to have a different connections..If the machine is working as a water cooled unit than it is quite normal to have a smaller dimension on condenser. For instance, if we need Q kilowatts to condense the refrigerant, than formula which is used is Q=mcDT
and by reducing DT the water flow will be less and therefore dimension of the pipe is less. You can check, mainly specific pressure drop on the water side is around 100Pa/m with condition that water velocity does not exceed 0.8m/s . Check how many kilowatts you need to condense the refrigerant, probably the DT is 5 or 8 and you will see what is connection.

[MilosBog]

Over compressor?