Liquid Receiver Calculations

I am trying to clarify the best method to calculate the capacity of a liquid receiver.

At the moment I presume that I calculate my liquid piping internal dimensions, suction piping internals dimensions and evaporator/condenser dimentions.

If I use the selected refrigerants specific density for liquid and gas and multiply by the total m3 this should give me the total refrigerant charge?

Thanks

Hi David,
I would calculate the liquid volume for the coolers (say 66% full) then the liquid line volume. You can either size the receiver to hold all the charge or say 80%, which most people would. The liquid in the condenser will stay in the condenser and the suction should not have liquid in it, except in pumped sysytems, where you would then use your recirc rate to determine the liquid flow and thus volume in the wet return.
Hope this helps. Regards. Andy:)

If your goal is to be able to isolate the system's entire charge in the receiver, then your approach is fine. You don't likely need a receiver of that size to obtain proper system operation, however.

If your goal is to size the smallest possible receiver for proper system operation, then more information will be needed... in particular, the type of head pressure controls.

Would my methods change any if I was trying to calculate the total system refrigerant charge in kg?

Thanks

David

If you want to calculate the receiver volume, Standard Refrigeration's website has a easy calculation for 80% capacity at this link: http://www.stanref.com/lr/receivers.htm#

Click on the selection tab and it will show you how to do it. This is what I use when I size receivers.

Norty

I always use next solution - 1/3 evaporator`s internal volume + internal volume of condenser + internal volume of liquid line + 20% for gas volume. But this solution suitable only for direct expansion systems.

SNi

I always use next solution - 1/3 evaporator`s internal volume + internal volume of condenser + internal volume of liquid line + 20% for gas volume. But this solution suitable only for direct expansion systems.

SNi