Control system for regulating large capacity rotating machinery
US4282719A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 12, 1979 |
| Grant date | Aug 11, 1981 |
| Priority date | — |
| Expiry date | Sep 12, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B30/70
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
The control system disclosed herein regulates a centrifugal compressor which has inlet guide vanes adjustable to vary the compressor capacity. A variable speed motor is connected to drive the compressor, and variation of this motor speed provides another input for regulating the compressor capacity. A control system achieves optimum energy efficiency, while avoiding surge, by the manner in which the motor speed and the inlet guide vane positions are regulated. To do this, a control signal must be derived to indicate the compressor head value. This signal is achieved by providing two signals, one related to the absolute condenser pressure, and the second related to the absolute evaporator pressure. The control system operates on these two signals to provide a third signal which is a function of a ratio, in which the numerator is the difference between the condenser and evaporator pressures, and the denominator is the evaporator pressure. Alternative measurement and processing techniques are described. This signal affords a very good indication of the compressor head and thus achieves increased efficiency of system operation, with consequent energy conservation, especially at lighter…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.