Cascade refrigeration system with modular ammonia chiller units
US9541311B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 17, 2010 |
| Grant date | Jan 10, 2017 |
| Priority date | — |
| Expiry date | Oct 15, 2034 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF25B2600/21
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
A cascade refrigeration system includes an upper portion having at least one modular chiller unit that provides cooling to at least one of a low temperature subsystem having a plurality of low temperature loads, and a medium temperature subsystem having a plurality of medium temperature loads. The modular chiller unit includes a refrigerant circuit having at least a compressor, a condenser, an expansion device, and an evaporator. An ammonia refrigerant mixed with a soluble oil circulates within the refrigerant circuit. A control device may be programmed to modulate the position of the expansion device so that a superheat temperature of the ammonia refrigerant near an outlet of the evaporator fluctuates within a substantially predetermined superheat temperature range to positively return soluble oil from the evaporator to the compressor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.