Refrigeration defrost cycles
US5575158A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 5, 1994 |
| Grant date | Nov 19, 1996 |
| Priority date | — |
| Expiry date | Oct 5, 2014 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF25B47/022
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
A hot gas defrost system for a refrigeration cycle, including at least one compressor, condenser, receiver, expansion valve and evaporator. During defrost, a pressure-sensitive valve to the condenser inlet is normally closed, and the flow of refrigerant from the compressor bypasses the condenser and flows to the receiver. However, when the pressure in the system reaches a critical point, the pressure-sensitive condenser inlet valve will open to release the excessive pressure. The condenser inlet valve is also temperature-sensitive and will open if the ambient temperature surrounding the condenser is above a specific point. Opening of the condenser valve permits the utilization of the hot gas in the condenser for defrost and to decrease the thermal shock resulting from the superheated vapor contacting the evaporator coil. The compressor, which needs a constant flow of liquid refrigerant for cooling, is continually supplied with liquid refrigerant. During refrigeration, a conduit connecting the receiver outlet and the compressor provides liquid refrigerant. During defrost, a conduit from the suction line to the compressor provides the required liquid refrigerant. The system also prov…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.