US5284026A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system for an air conditioning/refrigeration system
Assignee: Ecoair Corp
•
Filing: 1993-02-26
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Granted: 1994-02-08
•
Expires: 2013-02-26
Abstract
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.
Inventors
- 👤 James W. Powell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:07
CPC Classifications
F; F04; F04D; F04D27/00; F04D27/02; F04D27/0261; F24; F24F; F24F11/00; F24F11/30; F24F11/46; F24F11/62; F24F11/63; F24F11/64; F24F11/70; F24F11/80; F24F11/83; F24F11/84; F24F11/86; F24F11/87; F24F11/871; F25; F25B; F25B41/00; F25B41/30; F25B41/31; F25B41/34; F25B49/00; F25B49/02; F25B49/022; F24F1/00; F24F11/32; F24F2110/00; F24F2110/10; F24F2140/00; F24F2140/10; F24F2140/12; F24F2140/50; F24F2221/00; F24F2221/56; F25B2600/00; F25B2600/02; F25B2600/021; F25B2600/21; Y; Y02; Y02B; Y02B30/00; Y02B30/70
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
111 words
A method of controlling a refrigeration system having a working fluid and, in sequence, an evaporator, a variable speed centrifugal compressor, a condenser and an expansion valve, comprising: a) accelerating rotation of said compressor; b) measuring the acceleration of said compressor; c) measuring the temperature or pressure of the working fluid at said compressor; d) determining rate of change of the temperature or pressure of said working fluid during any acceleration of said compressor; e) decreasing acceleration of said compressor if said rate of change of the temperature or pressure of said working fluid indicates surging of said compressor; and f) repeating steps (b) through (e) until said compressor stops accelerating.
Claim 2
Independent Claim
111 words
A method of controlling a refrigeration system having a working fluid and, in sequence, an evaporator, a variable speed centrifugal compressor, a condenser and an expansion valve, comprising: a) accelerating rotation of said compressor; b) measuring the acceleration of said compressor; c) measuring the temperature or pressure of the working fluid at said compressor; d) determining rate of change of the temperature or pressure of said working fluid during any acceleration of said compressor; e) decreasing acceleration of said compressor if said rate of change of the temperature or pressure of said working fluid indicates surging of said compressor; and f) repeating steps (b) through (e) until said compressor stops accelerating.
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein said acceleration of said compressor in step (a) is to a predetermined maximum level.
Claim 4
Dependent Claim
24 words
The method of claim 1 wherein the temperature of the working fluid is measured in step (c) within or downstream adjacent to said compressor.
Claim 5
Dependent Claim
24 words
The method of claim 1 wherein the pressure of the working fluid is measured in step (c) within or downstream adjacent to said compressor.
Claim 6
Dependent Claim
100 words
Apparatus for controlling a refrigeration system having a working fluid and, in sequence, an evaporator, a variable speed centrifugal compressor, a condenser and an expansion valve, comprising: a sensor for measuring the acceleration of said compressor; a sensor for measuring the temperature or pressure of the working fluid at said compressor; and a microprocessor control for determining rate of change of the temperature or pressure of said working fluid during any acceleration of said compressor and decreasing acceleration of said compressor if said rate of change of the temperature or pressure of said working fluid indicates surging of said compressor.
Claim 7
Dependent Claim
100 words
Apparatus for controlling a refrigeration system having a working fluid and, in sequence, an evaporator, a variable speed centrifugal compressor, a condenser and an expansion valve, comprising: a sensor for measuring the acceleration of said compressor; a sensor for measuring the temperature or pressure of the working fluid at said compressor; and a microprocessor control for determining rate of change of the temperature or pressure of said working fluid during any acceleration of said compressor and decreasing acceleration of said compressor if said rate of change of the temperature or pressure of said working fluid indicates surging of said compressor.
Claim 8
Independent Claim
178 words
A method of controlling a refrigeration system having a working fluid and, in sequence, an evaporator, a variable speed centrifugal compressor, a condenser and an expansion valve, comprising: a) during an initiation period, accelerating rotation of said compressor while: i) measuring the acceleration of said compressor; and ii) 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 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; and ii) comparing said acceleration measurement during said subsequent period with said acceleration and working fluid rate of change of temperature or pressure measurements during said initiation period; and e) decreasing acceleration of said compressor if, for a comparable acceleration during said initiation period, said rate of change of the temperature or pressure of said working fluid during said initiation period indicates surging of said compressor.
Claim 9
Independent Claim
178 words
A method of controlling a refrigeration system having a working fluid and, in sequence, an evaporator, a variable speed centrifugal compressor, a condenser and an expansion valve, comprising: a) during an initiation period, accelerating rotation of said compressor while: i) measuring the acceleration of said compressor; and ii) 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 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; and ii) comparing said acceleration measurement during said subsequent period with said acceleration and working fluid rate of change of temperature or pressure measurements during said initiation period; and e) decreasing acceleration of said compressor if, for a comparable acceleration during said initiation period, said rate of change of the temperature or pressure of said working fluid during said initiation period indicates surging of said compressor.
Claim 10
Dependent Claim
139 words
Apparatus for controlling a refrigeration system having a working fluid and, in sequence, an evaporator, a variable speed centrifugal compressor, a condenser and an expansion valve, comprising: a sensor for measuring the acceleration of said compressor; a sensor for measuring rate of change of temperature or pressure of the working fluid at said compressor; and a microprocessor control for storing acceleration and working fluid rate of change of temperature or pressure measurements during an initiation period; comparing an acceleration measurement during said subsequent period with said acceleration and working fluid rate of change of temperature or pressure measurements during said initiation period; and decreasing acceleration of said compressor if, for a comparable acceleration during said initiation period, said rate of change of the temperature or pressure of said working fluid during said initiation period indicates surging of said compressor.
Claim 11
Dependent Claim
139 words
Apparatus for controlling a refrigeration system having a working fluid and, in sequence, an evaporator, a variable speed centrifugal compressor, a condenser and an expansion valve, comprising: a sensor for measuring the acceleration of said compressor; a sensor for measuring rate of change of temperature or pressure of the working fluid at said compressor; and a microprocessor control for storing acceleration and working fluid rate of change of temperature or pressure measurements during an initiation period; comparing an acceleration measurement during said subsequent period with said acceleration and working fluid rate of change of temperature or pressure measurements during said initiation period; and decreasing acceleration of said compressor if, for a comparable acceleration during said initiation period, said rate of change of the temperature or pressure of said working fluid during said initiation period indicates surging of said compressor.
References Cited (Backward Citations)
US3668883A
Cited
US3945418A
Cited
US4151725A
Cited
US4177649A
Cited
US4283920A
Cited
US4248055A
Cited
US4679404A
Cited
US4282719A
Cited
US4282718A
Cited
US4407139A
Cited
US4362030A
Cited
GB2109522A
Cited
US4582124A
Cited
US4510576A
Cited
US4611470A
Cited
US4514991A
Cited
US4566289A
Cited
US4603556A
Cited
US4527399A
Cited
US4538422A
Cited
US4535607A
Cited
US4738118A
Cited
US4745767A
Cited
US4646535A
Cited
US4546618A
Cited
US4646532A
Cited
US4571951A
Cited
US4581900A
Cited
US4608833A
Cited
US4660387A
Cited
US4662185A
Cited
US4616483A
Cited
US4722196A
Cited
US4689967A
Cited
US4715190A
Cited
US4753083A
Cited
US4689968A
Cited
US4798057A
Cited
US4686834A
Cited
US4821527A
Cited
US4870833A
Cited
US4667480A
Cited
US4734628A
Cited
US4794762A
Cited
US4765150A
Cited
US4914924A
Cited
US4768346A
Cited
US4885914A
Cited
US4856286A
Cited
JPH01222164A
Cited
US4877081A
Cited
US4930320A
Cited
US4858676A
Cited
US4968338A
Cited
US4938029A
Cited
US5157934A
Cited
US5065590A
Cited
US5054294A
Cited
US5083438A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-02-07 | 1997-08-09 | 1998-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-07 | 2001-08-09 | 2002-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-07 | 2005-08-09 | 2006-02-08 | $7700.00 | Window Closed / Lapsed |