US5062274A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Unloading system for two compressors
Assignee: Carrier Corp
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Filing: 1990-06-28
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Granted: 1991-11-05
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Expires: 2010-06-28
Abstract
Abstract An economizer is connected to a fluid line connecting the booster compressor and high stage compressor of a refrigeration system at a point downstream of the bypass for unloading the booster compressor. The economizer flow controls the discharge temperature of the second stage and, in addition, coacts with the bypassing of the booster compressor such that all of the flow supplied to the high stage is at system suction pressure when the bypass is fully open. When the booster compressor is fully unloaded and the unloading valve is fully open, the booster compressor is shut off and bypass flow for unloading reverses direction to permit flow from the condenser to the second stage past the shut off booster compressor.
Inventors
- 👤 David N. Shaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:45
CPC Classifications
F; F25; F25B; F25B5/00; F25B5/02; F25B1/00; F25B1/10; F25B40/00; F25B40/02; F25B49/00; F25B49/02; F25B49/022; F25B2400/00; F25B2400/13; F25B2600/00; F25B2600/02; F25B2600/025; F25B2600/0251; F25B2600/026; F25B2600/0261
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
225 words
An unloading system for a refrigeration system comprising: a first closed fluid loop serially including a first stage compressor means, a second stage compressor means, a condenser means, expansion means and evaporator means; a second fluid loop defining bypass means and fluidly connected to said first loop between a first end located intermediate said first and second stages and a second end located intermediate said evaporator means and said first stage; first valve means located in said second loop for unloading said first stage back to said second end of said second loop when said first valve means is open and said first stage compressor means is running and for bypassing said first stage from said second end to said first end of said second fluid loop when said first valve means is opened and said first compressor means is shut off; a third fluid loop defining an economizer means and fluidly connected to said first loop between a first end located intermediate said condenser means and said expansion means and a second end located intermediate said first and second stages; second valve means in said third loop for providing an economizer flow; whereby when said first valve means is fully open said second stage alone must handle refrigerant vapor generated by both said evaporator means and said economizer means thereby unloading said refrigeration system.
Claim 2
Dependent Claim
225 words
An unloading system for a refrigeration system comprising: a first closed fluid loop serially including a first stage compressor means, a second stage compressor means, a condenser means, expansion means and evaporator means; a second fluid loop defining bypass means and fluidly connected to said first loop between a first end located intermediate said first and second stages and a second end located intermediate said evaporator means and said first stage; first valve means located in said second loop for unloading said first stage back to said second end of said second loop when said first valve means is open and said first stage compressor means is running and for bypassing said first stage from said second end to said first end of said second fluid loop when said first valve means is opened and said first compressor means is shut off; a third fluid loop defining an economizer means and fluidly connected to said first loop between a first end located intermediate said condenser means and said expansion means and a second end located intermediate said first and second stages; second valve means in said third loop for providing an economizer flow; whereby when said first valve means is fully open said second stage alone must handle refrigerant vapor generated by both said evaporator means and said economizer means thereby unloading said refrigeration system.
Claim 3
Dependent Claim
24 words
The unloading system of claim 1 wherein said first end of said second loop is upstream of said second end of said third loop.
Claim 4
Dependent Claim
20 words
The unloading system of claim 1 wherein said first valve means is controlled responsive to the temperature in a zone.
Claim 5
Dependent Claim
24 words
The unloading system of claim 1 wherein said second valve means is actuated responsive to the temperature of refrigerant discharged from said compressor means.
Claim 6
Dependent Claim
16 words
The unloading system of claim 1 wherein said first valve means is controlled by microprocessor means.
Claim 7
Dependent Claim
27 words
The unloading system of claim 5 wherein said microprocessor means starts and stops said first stage compressor means responsive to said first stage compressor means being unloaded.
Claim 8
Independent Claim
188 words
A method for unloading a refrigeration system including a closed fluid loop serially including a first stage compressor means, a second stage compressor means, a condenser means, an expansion means and evaporator means comprising the steps of: operating the compressor means to compress refrigerant gas which is then circulated through the fluid loop; diverting liquid refrigerant from a point intermediate the condenser means and the expansion means and passing the diverted liquid refrigerant through a valve means to cause flashing and supplying the refrigerant passing through the valve means to the fluid loop at a point intermediate the first and second stages whereby an economizer circuit is established; diverting the output of the first stage compressor means to a point intermediate the evaporator means and the first stage compressor means when the first stage compressor means is running to unload the first stage compressor means whereby when the first stage compressor means is fully unloaded the interstage pressure is essentially that of the evaporator means; shutting off said first stage compressor means when said first stage compressor means is fully unloaded to bypass said first stage compressor means.
Claim 9
Independent Claim
188 words
A method for unloading a refrigeration system including a closed fluid loop serially including a first stage compressor means, a second stage compressor means, a condenser means, an expansion means and evaporator means comprising the steps of: operating the compressor means to compress refrigerant gas which is then circulated through the fluid loop; diverting liquid refrigerant from a point intermediate the condenser means and the expansion means and passing the diverted liquid refrigerant through a valve means to cause flashing and supplying the refrigerant passing through the valve means to the fluid loop at a point intermediate the first and second stages whereby an economizer circuit is established; diverting the output of the first stage compressor means to a point intermediate the evaporator means and the first stage compressor means when the first stage compressor means is running to unload the first stage compressor means whereby when the first stage compressor means is fully unloaded the interstage pressure is essentially that of the evaporator means; shutting off said first stage compressor means when said first stage compressor means is fully unloaded to bypass said first stage compressor means.
Claim 10
Dependent Claim
22 words
The method of claim 7 wherein the valve means is operated responsive to the temperature of the refrigerant leaving the second stage.
Claim 11
Dependent Claim
55 words
The method of claim 7 wherein shutting off said first stage compressor means avoids the inherent heating of refrigerant gas in passing through said first stage compressor means and thereby provides a slight increase in capacity of said second stage compressor means as well as eliminating the power draw of said first stage compressor means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-11-04 | 1995-05-06 | 1995-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-11-04 | 1999-05-06 | 1999-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-11-04 | 2003-05-06 | 2003-11-05 | $7700.00 | Window Closed / Lapsed |