Method for operating air conditioner

• US 5,115,643 A
• Filed: 11/30/1990
• Issued: 05/26/1992
• Est. Priority Date: 12/01/1989
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Tashiro, Kisuke, Hayata, Yoshiki, Watanabe, Masashi
• Primary Examiner(s): Makay, Albert J.
• Assistant Examiner(s): SOLLECITO, JOHN M
• Application Number:
  US07/620,056
• Time in Patent Office: 543 Days
• Field of Search: 62/129, 62/127, 62/126, 62/125, 62/115, 236/94, 165/11.1
• US Class Current: 62/115
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/38 Failure diagnosis
• CPC Class Codes: F24F 11/56 Remote control
• CPC Class Codes: F24F 11/63 Electronic processing
• CPC Class Codes: F24F 2110/10 Temperature
• CPC Class Codes: F24F 2110/12 of the outside air
• CPC Class Codes: F24F 2140/00 Control inputs relating to system states
• CPC Class Codes: F25B 13/00 Compression machines, plants or systems, with reversible cycle defrosting cycles F25B47/02
• CPC Class Codes: F25B 49/02 for compression type machines, plants or systems
• CPC Class Codes: G05D 23/1917 using digital means

Abstract

Disclosed is a method for operating an air conditioner which is basically composed of an outdoor unit and an indoor unit and whose operation is controlled on the basis of values measured by a plurality of temperature sensors. When any one of the plural sensors is disabled due to wire disconnection, short-circuit or like trouble, and when a specific sensor which has a complementary relation with the disabled sensor with respect to the heat cycle or which has an object of measurement substantially the same as that of the disabled sensor is normally functioning without any wire disconnection, short-circuit or like trouble, the value measured by the specific sensor is based to presume the value that will be measured by the disabled sensor if the disabled sensor functions normally, and the operation of the air conditioner is continued on the basis of the presumed value.

Claims

1. A method for operating an air conditioner to supply conditioned air to a room, comprising an outdoor unit and an indoor unit, said air conditioner being controlled by a plurality of temperature sensors including a suction air temperature sensor disposed in the indoor unit for measuring the temperature of suction air flow supplied to a heat exchanger in the indoor unit, and a radiation temperature sensor disposed in the indoor unit to measure the radiation temperature in the room, said suction air temperature sensor having a complementary relation with said radiation temperature sensor, said method comprising the steps of:

detecting at least one of a wire disconnection and short circuit of said suction air temperature sensor;

replacing a value measured by said suction air temperature sensor after the at least one of the wire disconnection and short circuit is detected with a value measured by said radiation temperature sensor if said radiation temperature sensor is operating normally;

continuing the operation of said air conditioner by controlling the air conditioner with the value measured by said radiation temperature sensor.

2. A method for operating an air conditioner to supply conditioned air, when the air conditioner is in a heating mode, comprising an outdoor unit and an indoor unit, said air conditioner being controlled by values of a plurality of temperature sensors including a discharge air temperature sensor disposed in the indoor unit for measuring the temperature of discharge air flow discharged from a heat exchanger within the indoor unit and a freezing temperature sensor for measuring the temperature of a refrigerant flowing into said heat exchanger within the indoor unit, said discharge air temperature sensor having a complementary relation with said freezing temperature sensor, said method comprising the steps of:

detecting at least one of a wire disconnection and short circuit of said discharge air temperature sensor disposed in the indoor unit;

replacing a value measured by said discharge air temperature sensor after the at least one of the wire disconnection and short circuit is detected with a sum of a value measured by said freezing temperature sensor and said predetermined value β

if said freezing sensor is operating normally, and

continuing the operation of the air conditioner by controlling the air conditioner with the sum of the value measured by said freezing temperature sensor and the predetermined value β

.

3. A method for operating an air conditioner to supply conditioned air, when the air conditioner is in a cooling mode, comprising an outdoor unit and an indoor unit, said air conditioner being controlled by values of a plurality of temperature sensors including

a discharge air temperature sensor disposed in the indoor unit for measuring the temperature of discharge air flow discharge from a heat exchanger in the indoor unit, a section air temperature sensor disposed in the indoor unit for measuring the temperature of suction air flow supplied to said indoor heat exchanger and a freezing temperature sensor for measuring the temperature of a refrigerant flowing into said indoor heat exchanger, said discharge air temperature sensor having a complementary relation with said suction air temperature sensor and said freezing temperature sensor, said method comprising the steps of:

detecting at least one of a wire disconnection and short circuit of said discharge air temperature sensor disposed in the indoor unit;

replacing a value measured by said discharge air temperature sensor after the at least one of the wire disconnection and short circuit is detected with a sum of a value measured by suction air temperature sensor and a value measured by said freezing temperature sensor if said suction air temperature sensor and said freezing temperature sensor is operating normally; and

continuing the operation of the air conditioner by controlling the air conditioner with the sum of the value measured by said suction air temperature sensor and the value measured by said discharge air temperature sensor.

4. A method for operating an air conditioner to supply conditioned air, comprising an indoor unit and an outdoor unit when the air conditioner is in a cooling mode, said air conditioner being controlled by values of a plurality of temperature sensors including a freezing temperature sensor for measuring the temperature of a refrigerant flowing into a heat exchanger in the indoor unit and a compressor suction gas temperature sensor disposed in the outdoor unit for measuring the temperature of suction gas flow supplied to a compressor in the outdoor unit, said freezing temperature sensor having a complementary relation with said compressor suction gas temperature sensor, said method comprising the steps of:

detecting at least one of a wire disconnection and a short circuit of said freezing temperature sensor,

replacing a value of said freezing temperature sensor after the at least one of the wire disconnection and the short circuit is detected with a predetermined value γ

when the value measured by said compressor suction gas temperature sensor is larger than the predetermined value γ

if said compressor suction gas temperature sensor is operating normally;

continuing operation of the air conditioner by controlling the air conditioner with the predetermined value γ

when the value measured by said compressor suction gas temperature sensor is larger than the predetermined value γ

.

5. A method for operating an air conditioner according to claim 4, wherein the plurality of temperature sensors further includes:

a discharge air temperature sensor disposed in the indoor unit for measuring the temperature of discharge air flow discharged from said indoor heat exchanger and a suction air temperature sensor disposed in the indoor unit for measuring the temperature of suction air flow supplied to said indoor heat exchanger, said method further comprises the steps of;

detecting at least one of wire disconnection and short circuit of said compressor suction gas temperature sensor disposed in the indoor unit;

replacing the value measured by said freezing temperature sensor after the malfunction is detected with a value obtained by subtracting a value measured by the suction air temperature sensor from a value measured by said discharge air temperature sensor;

continuing the operation of the air conditioner by controlling the air conditioner with the value obtained by the subtraction value.