Constant evaporator pressure slide valve modulator for screw compressor refrigeration system
US4583373A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 27, 1984 |
| Grant date | Apr 22, 1986 |
| Priority date | — |
| Expiry date | Sep 27, 2004 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF25B2600/026
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
A space conditioning closed loop refrigeration system, particularly a vehicle air conditioning system utilizing a positive displacement compressor having a slide valve for varying the capacity and shiftable between full load and full unload positions and vice versa and driven therebetween by a linear fluid motor having a movable member coupled to the slide valve and forming a first chamber which is normally dumped via a slide valve modulator to compressor suction pressure and a second chamber open to compressor discharge pressure. A restricted passage between chambers tends to cause the first chamber to reach compressor discharge pressure absent that chamber dumping to suction. The slide valve modulator selectively activates the venting of the first chamber to compressor suction pressure in response to fall of suction pressure below a predetermined value to prevent a serious reduction in evaporator temperature caused by either a reduction in load on the evaporator, an increase in speed of the compressor, or both. A temperature unloader in the form of a normally closed valve is connected within a bypass passage by passing the slide valve modulator to insure dumping of the first cham…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.