Earl A Russell

US Patent:

46465340, Mar 3, 1987

Filed:

Jul 15, 1985

Appl. No.:

6/755192

Inventors:

Earl Russell - Whittier CA

International Classification:

F25B 100

US Classification:

622284

Abstract:

The invention is an indirect controller, additive to any existing refrigeration system, for extending the operating range and increasing the efficiency of the system. The invention prioritizes the methods by which said system is loaded and unloaded by giving first priority to compressor speed regulation, with wide open inlet vanes, as the primary and most energy efficient method of meeting load requirements. The second priority is enabled upon the compressor reaching its minimum speed, whereby only the inlet vanes react to further system unloading by utilization of the system's existing vane control means. This secondary priority, although less energy efficient than speed control, extends the unloading range of the existing refrigeration system beyond that which was previously available. The means is additive to any existing refrigeration system which utilizes a centrifical compressor, variable inlet vanes, inlet vane controls and driven by an electric motor. Said means utilizes a position transducer to monitor inlet vane positions, a control means comparer which receives a vane position signal from said transducer and a variable frequency driver for varying the compressor's motor speed.