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US4620424A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of controlling refrigeration cycle

Assignee: Toshiba Corp
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Filing: 1984-12-27
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Granted: 1986-11-04
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Expires: 2004-12-27
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Abstract

Abstract In a method of controlling a refrigeration cycle constructed by connecting a compressor, an outdoor-side heat exchanger, an expansion valve, and an indoor-side heat exchanger, the temperature of a coolant ejected from the compressor is detected by a sensor, and the opening rate of the valve is adjusted in accordance with the detected temperature. When the detected temperature exceeds a prescribed upper limit, that opening rate of the valve which is indicated on that occasion is stored in a memory, and then the opening rate of the valve is increased to reduce the temperature of the ejected coolant to a lower level than a prescribed lower limit. After the temperature decreases from the lower limit, the opening rate of the valve is adjusted to a larger level than that level which is previously stored in a memory by a prescribed extent, thereby keeping the temperature of the ejected coolant between the upper and lower limits.

Inventors

  • 👤 Tatsuo Tanaka
  • 👤 Koichi Miyazaki
  • 👤 Eiji Kuwahara
  • 👤 Masaya Yamazaki
  • 👤 Keiichi Morita

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 02:17
CPC Classifications
F; F25; F25B; F25B41/00; F25B41/30; F25B41/31; F25B41/34; F25B41/35; F25B2600/00; F25B2600/25; F25B2600/2513; F25B2700/00; F25B2700/15; F25B2700/151; Y; Y02; Y02B; Y02B30/00; Y02B30/70

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 191 words
A method of controlling a refrigeration cycle in an apparatus including a compressor, an outdoor-side heat exchanger, an electromotive expansion valve, and an indoor-side heat exchanger which are connected in the order mentioned; said method comprising the steps of: detecting a load of the refrigeration cycle; adjusting an opening degree of the expansion valve in accordance with the magnitude of the detected load; storing in a memory a loaded opening degree of the expansion valve which is indicated when the detected load exceeds a prescribed upper limit; increasing the opening degree of the expansion valve to a predetermined upper level opening degree which is larger than said loaded opening degree in said storing step, to reduce the load of the refrigeration cycle to a level which is lower than a prescribed lower limit; and after the load of the refrigeration cycle decreases below the lower limit, decreasing the opening degree of the expansion valve to an opening degree which is larger than said loaded opening degree by a prescribed extent, and is smaller than said upper level opening degree thereby keeping the load of the refrigeration cycle within predetermined operating limits.
Claim 2
Independent Claim 191 words
A method of controlling a refrigeration cycle in an apparatus including a compressor, an outdoor-side heat exchanger, an electromotive expansion valve, and an indoor-side heat exchanger which are connected in the order mentioned; said method comprising the steps of: detecting a load of the refrigeration cycle; adjusting an opening degree of the expansion valve in accordance with the magnitude of the detected load; storing in a memory a loaded opening degree of the expansion valve which is indicated when the detected load exceeds a prescribed upper limit; increasing the opening degree of the expansion valve to a predetermined upper level opening degree which is larger than said loaded opening degree in said storing step, to reduce the load of the refrigeration cycle to a level which is lower than a prescribed lower limit; and after the load of the refrigeration cycle decreases below the lower limit, decreasing the opening degree of the expansion valve to an opening degree which is larger than said loaded opening degree by a prescribed extent, and is smaller than said upper level opening degree thereby keeping the load of the refrigeration cycle within predetermined operating limits.
Claim 3
Dependent Claim 31 words
The method according to claim 1, wherein said step of detecting the load of the refrigeration cycle includes a process of detecting the temperature of a coolant ejected from the compressor.
Claim 4
Dependent Claim 31 words
The method according to claim 1, wherein said step of detecting the load of the refrigeration cycle includes a process of detecting the magnitude of a current conducted through the compressor.
Claim 5
Dependent Claim 31 words
The method according to claim 1, wherein said step of detecting the load of the refrigeration cycle includes a process of detecting the pressure of a coolant ejected from the compressor.
Claim 6
Dependent Claim 27 words
The method according to claim 1, wherein said step of increasing the opening degree of the expansion valve includes a process of fully opening the expansion valve.
Claim 7
Independent Claim 195 words
An apparatus for controlling a refrigeration cycle, comprising: compressor means for delivering a refrigerant under pressure; at least one heat exchanger means for exchanging thermal energy contained in the refrigerant with an ambient atmosphere; means for sensing a load on said compressor means; means for altering said load on said compressor means; and control means for: (1) first controlling said altering means to a first predetermined level to thereby cause said load to assume a first value, (2) controlling said altering means to an open level to decrease the load on said compressor means when a predetermined upper limit of load on said compressor means is sensed by said sensing means, said open level being sufficient to decrease the load of said compressor to a value lower than a predetermined lower limit, (3) storing a value representing the level of said altering means at the point when said upper limit of load is obtained, (4) adjusting the level of said altering means to produce a value which differs from said stored value by a predetermined amount, and (5) again repeating said controlling, storing, and adjusting steps until a constant load of proper value is attained.
Claim 8
Independent Claim 195 words
An apparatus for controlling a refrigeration cycle, comprising: compressor means for delivering a refrigerant under pressure; at least one heat exchanger means for exchanging thermal energy contained in the refrigerant with an ambient atmosphere; means for sensing a load on said compressor means; means for altering said load on said compressor means; and control means for: (1) first controlling said altering means to a first predetermined level to thereby cause said load to assume a first value, (2) controlling said altering means to an open level to decrease the load on said compressor means when a predetermined upper limit of load on said compressor means is sensed by said sensing means, said open level being sufficient to decrease the load of said compressor to a value lower than a predetermined lower limit, (3) storing a value representing the level of said altering means at the point when said upper limit of load is obtained, (4) adjusting the level of said altering means to produce a value which differs from said stored value by a predetermined amount, and (5) again repeating said controlling, storing, and adjusting steps until a constant load of proper value is attained.
Claim 9
Dependent Claim 52 words
An apparatus as in claim 6 wherein said altering means is an electromotive expansion valve having a valve body defining an internal area and a valve rod which is capable of movement within said valve body, said valve rod being of varying areas, thereby selectively restricting fluid flow through said valve body.
Claim 10
Dependent Claim 25 words
A device as in claim 7 wherein said valve rod is formed of step sections with areas that are progressively reduced toward one end thereof.
Claim 11
Dependent Claim 21 words
A device as in claim 7 wherein said valve rod has one portion which is formed into a substantially conical shape.

References Cited (Backward Citations)

US2453439A Cited
US4420947A Cited
US4459818A Cited
US4523435A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-11-03 1990-05-05 1990-11-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-11-03 1994-05-05 1994-11-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-11-03 1998-05-05 1998-11-04 $7700.00 Window Closed / Lapsed

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