Lubricant composition for ammonia based refrigerants with good seal performance

摘要

A problem with refrigeration systems using ammonia as the refrigerant and hydrocarbon lubricants is that the seals/gaskets of the systems have a tendency to harden and shrink. This can cause leakage of the refrigerant and eventually require disassembly of the equipment and replacement of the seals. The addition of a small amount polyether having an aromatic fragment of 6-18 carbon atoms or an aliphatic fragment of 10-22 carbon atoms can soften the seals and partially re-swell the seals solving the leakage problem and avoiding expensive maintenance costs. Alternatively a polyether of 1,2-butylene oxide which is more oil soluble than most other polyethers with a smaller Z group e.g. derived from alkanols of 1 to 9 carbon would be effective at reducing hardening and shrinkage.