Refrigeration system on/off cycle
US4180986A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 25, 1978 |
| Grant date | Jan 1, 1980 |
| Priority date | — |
| Expiry date | Apr 25, 1998 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF25B2400/22
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A positive displacement compressor, such as a helical screw rotary compressor without capacity control element, is coupled in a refrigeration loop main line between the evaporator and an oil separator and upstream of the condensor. To unload the screw compressor at low evaporator load, any refrigerant discharging from the compressor is bypassed by a line connecting the suction and discharge sides of the screw compressor, and main line connection from the evaporator to the screw compressor is shut off such that the driven, unloaded screw compressor pulls oil from the separator through a restrictor and oil injection port and some refrigerant vapor which passes to the evaporator side through the screw compressor bypass line. As the evaporator pressure increases, the evaporator is connected through a restrictor within the main line to the screw compressor suction. As the evaporator load increases, normal operation returns, with the bypass line being closed and oil fed from the oil separator to the screw compressor injection port bypassing the restrictor for that oil line.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.