Refrigeration plant

A refrigeration plant is the vapor-compression system that cools the ship’s provision rooms, air-conditioning, and any reefer cargo or stores, working on a compressor, condenser, expansion valve, and evaporator cycle. The compressor raises the refrigerant pressure, the seawater- or air-cooled condenser rejects heat, the expansion device drops the pressure, and the evaporator absorbs heat from the cooled space. Marine plants have shifted from R-22 and HFC refrigerants such as R-404A and R-134a toward lower-GWP options and CO2 (R-744) under MARPOL Annex VI Reg 12 ozone controls and the Kigali HFC phase-down.