The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 11, 1981
Filed:
Sep. 12, 1979
Kenneth J Kountz, Hoffman Estates, IL (US);
Richard A Erth, York, PA (US);
Dean K Norbeck, York, PA (US);
Borg-Warner Corporation, Chicago, IL (US);
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 loads and low heads.