US 5,335,507 A · Control system for an air conditioning/refrigeration system

Abstract

A microprocessor-based air conditioning/refrigeration control system adapted for use with a variable speed compressor measures acceleration of the compressor and the temperature or pressure of the refrigerant exiting therefrom, determines the rate of change of the temperature or pressure of the refrigerant, and decreases acceleration of the compressor if the rate of change of the temperature or pressure of the working fluid indicates surging of the compressor. Superheat of the refrigerant is maintained at a first predefined level while the compressor is operating at constant speed and is increased to a second, higher predefined level while the compressor is accelerating. The system is able to diagnose deterioration of the compressor by measuring and comparing power input to the compressor and rate of change of temperature or pressure of the refrigerant at the compressor between initial and subsequent periods, and differentiate between deterioration of a drive component or a pressurizing component of the compressor.

Claims6

Dependent claims

A method of monitoring a variable speed centrifugal compressor in a refrigeration system having a working fluid, comprising:

a) during an initiation period, accelerating rotation of said compressor while:
i) measuring the acceleration of said compressor;
ii) measuring power input to said compressor;
and
iii) measuring rate of change of temperature or pressure of the working fluid at said compressor;
b) repeating step (a) to assemble a plurality of said measurements;
c) storing said acceleration, power input and working fluid rate of change of temperature or pressure measurements during said initiation period;
d) subsequent to said initiation period, accelerating rotation of said compressor while:
i) measuring the acceleration of said compressor;
ii) measuring power input to said compressor;
and
iii) measuring rate of change of temperature or pressure of the working fluid at said compressor;
and
e) determining all indication of deterioration of said compressor by comparing said acceleration, power input and working fluid rate of change of temperature or pressure measurements during said subsequent period with said acceleration, power input and working fluid rate of change of temperature or pressure measurements during said initiation period.

11 more elements

Dependencies are inferred from the claim text.

Control system for an air conditioning/refrigeration system

Life of this patent

Control system for an air conditioning/refrigeration system

Life of this patent

Abstract

Claims6