US5186014A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low refrigerant charge detection system for a heat pump
Assignee: Delphi Technologies Inc
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Filing: 1992-07-13
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Granted: 1993-02-16
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Expires: 2012-07-13
Abstract
Abstract A low refrigerant charge detector is operatively connected in either the suction or discharge line of a compressor of a heat pump system, wherein the compressor is in turn connected to a reversing valve. The detector includes a pressure sensor connected in one line and transmits pressure readings to a computer. During reversal of the flow of liquid in the system by the reversing value, the time at which the pressure exceeds or drops below a predetermined value is measured. The comparison depends on if the sensor is connected in the suction line or discharge line. If the time exceeds a minimum time, a low charge of refrigerant is indicated.
Inventors
- 👤 Robert M. Runk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:20
CPC Classifications
F; F25; F25B; F25B49/00; F25B49/005; F25B2500/00; F25B2500/22; F25B2500/222
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
113 words
A method of detecting low refrigerant charge in a heat pump system of the type having a compressor operatively connected to a reversing valve, the method including the steps of: sensing the pressure of the refrigerant at a fluid line of the compressor, detecting a first time at which the sensed pressure crosses a first predetermined pressure value in response to reversal of the reversing value and reversal of the fluid flow direction, detecting a second time at which the sensed pressure crosses a second predetermined pressure value, and indicating a low refrigerant charge in the heat pump system when the time difference between the first and second times crosses a predetermined value.
Claim 2
Independent Claim
113 words
A method of detecting low refrigerant charge in a heat pump system of the type having a compressor operatively connected to a reversing valve, the method including the steps of: sensing the pressure of the refrigerant at a fluid line of the compressor, detecting a first time at which the sensed pressure crosses a first predetermined pressure value in response to reversal of the reversing value and reversal of the fluid flow direction, detecting a second time at which the sensed pressure crosses a second predetermined pressure value, and indicating a low refrigerant charge in the heat pump system when the time difference between the first and second times crosses a predetermined value.
Claim 3
Independent Claim
94 words
A method of detecting low refrigerant charge in a heat pump system of the type having a compressor operatively connected to a reversing valve, the method including the steps of: sensing the pressure of the refrigerant flowing in one fluid line of the compressor connected to the reversing value, detecting the time period that the sensed pressure crosses a predetermined switching pressure in response to reversal of the fluid flow direction by reversing the reversing valve, indicating a low refrigerant charge in the heat pump system when the time period crosses a predetermined value.
Claim 4
Independent Claim
94 words
A method of detecting low refrigerant charge in a heat pump system of the type having a compressor operatively connected to a reversing valve, the method including the steps of: sensing the pressure of the refrigerant flowing in one fluid line of the compressor connected to the reversing value, detecting the time period that the sensed pressure crosses a predetermined switching pressure in response to reversal of the fluid flow direction by reversing the reversing valve, indicating a low refrigerant charge in the heat pump system when the time period crosses a predetermined value.
Claim 5
Dependent Claim
129 words
A detection apparatus for detecting low refrigerant charge in a heat pump system of the type having a compressor operatively connected by fluid lines to a reversing value and including an evaporator and expansion device and condenser, said apparatus comprising; pressure sensing means operatively connected to a fluid line of the compressor for sensing the pressure of refrigerant flowing in the fluid line to produce a pressure signal indicative thereof, computer means for receiving said pressure signal and for determining the time period that the sensed pressure crosses a predetermined switching pressure in response to reversal of the fluid flow direction by reversing the reversing value and for producing a warning signal; and indicating means for receiving said warning signal and for producing an indication of low refrigerant charge.
Claim 6
Dependent Claim
129 words
A detection apparatus for detecting low refrigerant charge in a heat pump system of the type having a compressor operatively connected by fluid lines to a reversing value and including an evaporator and expansion device and condenser, said apparatus comprising; pressure sensing means operatively connected to a fluid line of the compressor for sensing the pressure of refrigerant flowing in the fluid line to produce a pressure signal indicative thereof, computer means for receiving said pressure signal and for determining the time period that the sensed pressure crosses a predetermined switching pressure in response to reversal of the fluid flow direction by reversing the reversing value and for producing a warning signal; and indicating means for receiving said warning signal and for producing an indication of low refrigerant charge.
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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) | 1996-02-16 | 1996-08-17 | 1997-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-02-16 | 2000-08-17 | 2001-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-02-16 | 2004-08-17 | 2005-02-16 | $7700.00 | Window Closed / Lapsed |