Method and apparatus for limiting a critical variable of a group of compressors or an individual compressor
US6217288A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 20, 1998 |
| Grant date | Apr 17, 2001 |
| Priority date | — |
| Expiry date | Jan 20, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B5/01
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
This invention discloses a method for limiting a critical variable (such as, discharge pressure or suction pressure or pressure ratio) of either a compressor station or an individual compressor when these machines are subjected to large, fast disturbances. Each configuration, whether a station or an individual compressor, is equipped with two PID controllers: (1) a main controller for compressor critical variables and (2) a limiting controller that participates in modulating recycle valves. At the onset of sudden, large changes of mass flow at a compressor's or station's discharge, the effectiveness of the two controllers (acting independently) may be insufficient to prevent discharge pressure from reaching the shutdown set point which, in turn, disrupts the process supported by the compressors, and the longevity of the drivers is diminished. For these reasons, this disclosure relates specifically to a technique that combines the functions of the main and limiting controllers. Because of the complementary (synergistic) interaction of the controllers, an earlier and faster opening of the antisurge valves is initiated, and pressure at the discharge header is effectively limited.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.