Ronald W Bailey

US Patent:

40609979, Dec 6, 1977

Filed:

Mar 31, 1976

Appl. No.:

5/672255

Inventors:

Gilbert F. Shultz - Novi MI
Ronald W. Bailey - Westland MI

Assignee:

Application Engineering Corporation - Elk Grove Village IL

International Classification:

F25D 1702

US Classification:

62180

Abstract:

A control system for a water chiller comprising a heat exchanger, a pump for circulating a coolant comprising water or other process fluid through a path including the heat exchanger, a process apparatus, and a reservoir, and a compressor for circulating refrigerant through a path including the heat exchanger and a condenser; the control system includes electronic sensors for sensing the water supply pressure to the process apparatus, the refrigerant pressures at the compressor inlet and outlet, the water level in the reservoir, and the water temperatures at the heat exchanger inlet and outlet. The control system further includes logic and control circuits which de-activate the pump for conditions of inadequate (or excessive) water pressure or inadequate water in the reservoir, which vary the refrigerant circulation to maintain the water temperature essentially constant at a preset level, and which protect the chiller against over or under-pressure refrigerant conditions and against excessive cooling, affording precision control and continuous monitoring of all chiller operations.