Hello to everyone. Nice to be here and posting for the same time.
Iīm having some trouble trying to make the liquid refrigerant reaching the TXVs. Liquid and suction lines to the evaporators are a little long: 20 - 25 meters with 7 meter vertical risers. The liquid receiver is half full, so I donīt believe there is a lack of refrigerant. I changed the cores of the filter drier which is located next to the receiver, just in case they were plugged. There is a differential pressure regulating valve downstream from the drier, which throttles the liquid flow, but it only activates during defrost. The OPR valve which keeps the receiver at a minimum pressure seems to be working all right: there is a gauge in the receiver which reads the pressure and it doesnīt get below 180 psig.
There are 14 different refrigeration circuits, and none of them seems to be getting enough liquid. The rack contains 7 compressors, but only two of them work at any time since suction pressure gets too low if any more compressors are switched on. I checked a few of the TXVs filter mesh and all came out clean.
Do you think that it would be any helpful if I try to raise the reciever pressure a little bit in an attempt to overcome piping loses ? Someone told me about a hermetic type of liquid refrigerant pump used to presurize the liquid line and force the liquid into the evaporators, but I have no knowledge about this device. I would appreciate any comments. Thanks!!