Controller and a method for controlling an expansion valve of a refrigeration system
US6854285B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 8, 2003 |
| Grant date | Feb 15, 2005 |
| Priority date | — |
| Expiry date | Oct 8, 2023 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF25B2700/21175
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
A controller for an expansion valve of a refrigeration system for cooling a medium is configured to include, in the generation of a control signal, a measure of the evaporation temperature (T0) of the refrigerant in an evaporator and a measure of a property of the cooled medium, preferably without influence from a measure of the superheat temperature (SH) of the refrigerant. The controller comprises a PI-element for integrating and for producing a control signal for the expansion valve for controlling the flow of refrigerant into the evaporator, the PI-element being arranged in an inner control loop, a reference for which is produced by an outer control loop. The controller allows for fast response to disturbances and/or fast response of the medium temperature when the operating conditions of the refrigeration system are changed and/or fast response during start-up of the refrigeration system and maintains stable operation conditions with low, but positive superheating and a stable evaporation pressure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.