EP0924480A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Vapor line pressure control
Assignee: Carrier Corp
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Filing: 1998-12-04
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Granted: —
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Expires: 2018-12-04
Abstract
Abstract In a heat pump system designed for use with a relatively low pressure refrigerant, provision is made , by use of a vapor pressure control system, to use a higher pressure refrigerant without replacement of the indoor coil and the line set. The vapor pressure is sensed during periods of heat pump operation, and when the pressure reaches a predetermined maximum threshold level, the outdoor fan speed is reduced to thereby cause the vapor pressure to be reduced. When the vapor pressure is reduced to a predetermined minimum threshold level, then the fan speed is resumed so as thereby allow the vapor pressure to again be increased.
Inventors
- 👤 Sathish R. Das
- 👤 Don A. Schuster
- 👤 Larry J. Burkhart
- 👤 Ronald G. Butcher
- 👤 Timothy J. Perry
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 19:03
CPC Classifications
F; F25; F25B; F25B13/00; F24; F24F; F24F11/00; F24F11/70; F24F11/80; F24F11/87; F24F11/871; F24F11/89; F25B49/00; F25B49/02; F25D; F25D21/00; F25D21/002; F25D21/02; F24F2140/00; F24F2140/10; F24F2140/12; F25B2313/00; F25B2313/029; F25B2313/0292; F25B2313/0294; F25B2313/031; F25B2313/0314; F25B2313/0315; F25B2400/00; F25B2400/18; F25B2600/00; F25B2600/02; F25B2600/025; F25B2600/11; F25B2600/111; F25B2600/23; F25B2700/00; F25B2700/19; Y; Y02; Y02B; Y02B30/00; Y02B30/70; Y10; Y10S; Y10S62/00; Y10S62/17
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
129 words
In a heat pump system having a compressor, outdoor and
indoor fans, outdoor and indoor coils interconnected by liquid and vapor lines, and a
reversing valve operable to selectively direct refrigerant flow for either cooling or
heating modes of operation, a control system for allowing the use of a replacement
refrigerant having a substantially higher pressure than the refrigerant for which the
system was designed, without replacement of the lines in the indoor coil or the vapor
line, characterized by: means for sensing when the pressure in the vapor lines exceeds a
predetermined pressure limit during periods of operation in the heat pump mode; and means for responsively reducing the speed of the outdoor fan to
thereby lower the pressure to an acceptable limit below said predetermined pressure
limit.
Claim 2
Dependent Claim
27 words
A heat pump system as set forth in claim 1 wherein said
pressure sensing means is a pressure switch located in an outdoor unit in the system.
Claim 3
Dependent Claim
29 words
A heat pump system as set forth in claim 2 wherein said
pressure switch is a normally closed switch in series with a drive motor of said
outdoor fan.
Claim 4
Dependent Claim
41 words
A heat pump system as set forth in claim 3 wherein said
pressure switch is designed to open at a first predetermined pressure level and to close
at a second predetermined pressure level below that of said first predetermined
pressure level.
Claim 5
Dependent Claim
24 words
A heat pump system as set forth in claim 1 wherein said speed
reducing means is a switch that turns off the outdoor fan.
Claim 6
Dependent Claim
126 words
In a heat pump system having a outdoor unit with a
compressor, a fan, and a heat exchanger coil, and an indoor unit connected thereto by
liquid and vapor tubes, a control system for limiting the pressure in said vapor line
during periods of heat pump operation characterized by: a vapor pressure switch with a pressure sensing portion operatively
connected in the outdoor unit for sensing the pressure in the vapor line, and with an
electrical portion operatively connected in series with a motor of the fan; and wherein when said pressure switch portion operates to sense a
predetermined pressure limit in the vapor line and causes said switch portion to reduce
the speed of the fan and thereby reduce the pressure in the vapor line.
Claim 7
Dependent Claim
19 words
A heat pump as set forth in claim 6 wherein said vapor pressure
switch is a normally closed switch.
Claim 8
Dependent Claim
41 words
A heat pump as set forth in claim 7 wherein said vapor pressure
switch is designed to open at a first predetermined pressure level and to close at a
second predetermined pressure level below that of said first predetermined pressure
level.
Claim 9
Dependent Claim
19 words
A heat pump system as set forth in claim 6 wherein said switch
portion turns off the outdoor fan.
Claim 10
Dependent Claim
119 words
In a heat pump of the type having a compressor, outdoor and
indoor fans, outdoor and indoor coils interconnected by respective liquid and vapor
interconnect tubes, wherein the pressure in at least one of said tubes is susceptible to
exceeding a predetermined maximum operating pressure during periods of operation
in the heating mode, a method of controlling the pressure in said tubes characterized
by the steps: sensing the pressure in said vapor line; comparing said sensed pressure with a predetermined maximum
threshold pressure which is below said predetermined maximum design pressure; and when said sensed pressure is equal to said maximum threshold
pressure, reducing the speed of the outdoor fan so as to lower the pressure in said
tubes.
Claim 11
Dependent Claim
42 words
A method as set forth in claim 10 and including the additional
step of, when said sensed pressure has been reduced to a minimum threshold pressure,
increasing the speed of the outdoor fan so as to raise the pressure in said tubes.
Claim 12
Dependent Claim
28 words
A method as set forth in claim 10 wherein said step of reducing
the speed of the outdoor fan is accomplished by turning off the electrical power
thereto.
Claim 13
Dependent Claim
27 words
A method as set forth in claim 11 wherein said step of
increasing the speed of the outdoor fan is accomplished by resuming the electrical
power thereto.
References Cited (Backward Citations)
No citation records indexed.
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