초록 ▼

A refrigeration system employing a screw compressor and a falling film evaporator makes use of high-side pressure to drive lubricant, which escapes the compressor and collects as a lubricant-rich mixture of lubricant and refrigerant in the system evaporator, back to the compressor. The mixture is cy

A refrigeration system employing a screw compressor and a falling film evaporator makes use of high-side pressure to drive lubricant, which escapes the compressor and collects as a lubricant-rich mixture of lubricant and refrigerant in the system evaporator, back to the compressor. The mixture is cyclically exposed to high-side pressure for a period of time which (i) varies in accordance with the difference between a sensed condenser-related pressure and a sensed evaporator-related pressure and (ii) is calculated to maintain a predetermined oil concentration in the lubricant-rich mixture in the evaporator so as to minimize the parasitic losses to system efficiency associated with the oil return process.

대표청구항 ▼

[ What is claimed is:] [35.] A method of returning refrigerant which pools in liquid form in the evaporator of a refrigeration system, after having been distributed therein a first time for heat exchange contact with a heat transfer medium flowing therethrough, to a location in said evaporator from

[ What is claimed is:] [35.] A method of returning refrigerant which pools in liquid form in the evaporator of a refrigeration system, after having been distributed therein a first time for heat exchange contact with a heat transfer medium flowing therethrough, to a location in said evaporator from where said liquid refrigerant is redistributed for heat exchange contact with said heat transfer medium, comprising the steps of:collecting said liquid refrigerant in a housing;isolating the interior of said housing from the interior of said evaporator; andexposing said collected liquid refrigerant to a pressure sufficient to drive it to said location in said evaporator.