Air conditioner

• US 6,035,653 A
• Filed: 03/31/1998
• Issued: 03/14/2000
• Est. Priority Date: 04/17/1997
• Status: Expired due to Term

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Itoh, Satoshi, Iritani, Kunio
• Primary Examiner(s): Bennett, Henry
• Assistant Examiner(s): Norman, Marc
• Application Number:
  US09/052,788
• Time in Patent Office: 714 Days
• Field of Search: 12/228.4, 12/173, 12/176.5, 12/204, 12/205, 12/222, 12/223, 12/224, 12/225
• US Class Current: 62/228.4
• CPC Class Codes: B60H 1/00878 the components being temperature regulating devices
• CPC Class Codes: B60H 1/3205 Control means therefor
• CPC Class Codes: B60H 1/3207 for minimizing the humidity of the air
• CPC Class Codes: B60H 1/3208 Vehicle drive related control of the compressor drive means, e.g. for fuel saving purposes
• CPC Class Codes: B60H 1/3211 for increasing the efficiency of a vehicle refrigeration cycle
• CPC Class Codes: B60H 1/3219 for improving the response time of a vehicle refrigeration cycle
• CPC Class Codes: B60H 2001/325 of the refrigerant at a compressing unit
• CPC Class Codes: B60H 2001/3255 related to temperature
• CPC Class Codes: B60H 2001/3258 of the air at a condensing unit
• CPC Class Codes: B60H 2001/3261 of the air at an evaporating unit
• CPC Class Codes: B60H 2001/3272 to control the revolving speed of a compressor
• CPC Class Codes: B60H 2001/3282 to control the air flow
• CPC Class Codes: B60H 2001/3285 related to an expansion unit
• CPC Class Codes: F25B 2600/111 of condenser fans
• CPC Class Codes: F25B 41/20 Disposition of valves, e.g. of on-off valves or flow control valves expansion valves F25B41/31
• CPC Class Codes: F25B 41/24 Arrangement of shut-off valves for disconnecting a part of the refrigerant cycle, e.g. an outdoor part
• CPC Class Codes: F25B 49/027 Condenser control arrangements
• CPC Class Codes: F25B 6/04 arranged in series

Abstract

An air conditioner capable of enhancing responsivity of a blowout temperature of conditioned air while preventing occurrence of an overshoot or undershoot condition of the blowout temperature when a user gives an instruction to change the blowout temperature in a dehumidifying operation mode. In a control state, if a set temperature level is adjusted to increase a blowout temperature of conditioned air by increasing the target condenser outlet temperature, the rotating speed of the refrigerant compressor is increased, while the restriction opening of the heating expansion valve is maintained. Thus, the condenser outlet temperature is regulated to the target temperature with minimal undershoot or overshoot of the target temperature.

Claims

1. An air conditioner, comprising:

a refrigerating cycle system including a refrigerant compressor, a cooling evaporator equipped in an air-conditioning housing, a heating condenser equipped at an air downstream position of said cooling evaporator in said air-conditioning housing, an external heat exchanger disposed outside said air-conditioning housing, and variable flow restriction means equipped on a refrigerant flow path between said external heat exchanger and said heating condenser,

said refrigerating cycle system being arranged to enable a dehumidifying operation mode in which a refrigerant discharged from said refrigerant compressor passes through said external heat exchanger after passing through, and being condensed by, said heating condenser, the refrigerant then being evaporated by said cooling evaporator to cool air introduced into said air-conditioning housing, the cooled air then being heated by said heating condenser;

dehumidification-dominant air-conditioning control means for regulating a cooling dehumidification level required for said cooling evaporator by controlling a rotating speed of said refrigerant compressor according to air-conditioning environmental factors, and for regulating a blowout temperature level of conditioned air from said heating condenser by adjustment of heating performance of said heating condenser through control of a restriction opening of said variable flow restriction means, according to said air-conditioning environmental factors, when said dehumidifying operation mode is selected;

signal generating means for generating a signal for allowing a user to adjust a set temperature level of said blowout temperature;

blowout-temperature-dominant air-conditioning control means for regulating said blowout temperature by controlling the rotating speed of said refrigerant compressor when a signal for adjusting said set temperature level is generated by said signal generating means in said dehumidifying operation mode; and

wherein the blowout-temperature-dominant air conditioning control means further maintains the restriction opening of said variable flow restriction means when the signal for adjusting said set temperature level is generated by said signal generating means in said dehumidifying operation mode.

2. An air conditioner, comprising:

a refrigerating cycle system including a refrigerant compressor, a cooling evaporator equipped in an air-conditioning housing, a heating condenser equipped at an air downstream position of said cooling evaporator in said air-conditioning housing, an external heat exchanger disposed outside said air-conditioning housing, and variable flow restriction means equipped on a refrigerant flow path between said external heat exchanger and said heating condenser,

said refrigerating cycle system being arranged to enable a dehumidifying operation mode in which a refrigerant discharged from said refrigerant compressor passes through said external heat exchanger after passing through, and being condensed by, said heating condenser, the refrigerant then being evaporated by said cooling evaporator to cool air introduced into said air-conditioning housing, the cooled air then being heated by said heating condenser;

dehumidification-dominant air-conditioning control means for regulating a cooling dehumidification level required for said cooling evaporator by controlling a rotating speed of said refrigerant compressor according to air-conditioning environmental factors, and for regulating a blowout temperature level of conditioned air from said heating condenser by adjustment of heating performance of said heating condenser through control of a restriction opening of said variable flow restriction means, according to said air-conditioning environmental factors, when said dehumidifying operation mode is selected;

signal generating means for generating a signal for allowing a user to adjust a set temperature level of said blowout temperature;

blowout-temperature-dominant air-conditioning control means for regulating said blowout temperature by controlling the rotating speed of said refrigerant compressor when a signal for adjusting said set temperature level is generated by said signal generating means in said dehumidifying operation mode;

suction air temperature sensor means for detecting a suction air temperature of said cooling evaporator;

evaporator blowout air temperature sensor means for detecting an evaporator blowout air temperature after air passes through said cooling evaporator;

condenser blowout air temperature sensor means for detecting a condenser blowout air temperature after air passes through said heating condenser; and

condenser blowout air temperature calculating means for calculating a target condenser blowout air temperature for said condenser blowout air temperature according to at least said air-conditioning environmental factors;

wherein said dehumidification-dominant air-conditioning control means, when said set temperature is maintained by said signal generating means in said dehumidifying operation mode, controls the rotating speed of said refrigerant compressor so that said dehumidification level required for said cooling evaporator is satisfied according to said suction air temperature and said evaporator blowout air temperature, said evaporator blowout air temperature to prevent occurrence of frosting on said cooling evaporator, while controlling said restriction opening to regulate said blowout temperature to said target condenser blowout air temperature, and

said blowout-temperature-dominant air-conditioning control means, when said signal generating means generates a signal for changing said set temperature, stops a control state provided by said dehumidification-dominant air-conditioning control means and controls the rotating speed of said refrigerant compressor forcedly while maintaining said restriction opening to regulate said blowout temperature to said target condenser blowout air temperature.

3. An air conditioner according to claim 2, further comprising:

target evaporator blowout air temperature calculating means for calculating a target evaporator blowout air temperature of said evaporator blowout air temperature so that said required dehumidification level is satisfied according to said suction air temperature and said evaporator blowout air temperature and that said evaporator blowout air temperature becomes higher than said predetermined control temperature;

wherein said dehumidification-dominant air-conditioning control means controls the rotating speed of said refrigerant compressor to regulate said evaporator blowout air temperature to said target evaporator blowout air temperature, and

said blowout-temperature-dominant air-conditioning control means stops a control state provided by said dehumidification-dominant air-conditioning control means and controls the rotating speed of said refrigerant compressor.

4. An air conditioner according to claim 2, wherein when said blowout temperature reaches said target condenser blowout air temperature, a control state provided by said dehumidification-dominant air-conditioning control means is restored, the rotating speed of said refrigerant compressor is controlled to regulate said evaporator blowout temperature to said target evaporator blowout air temperature, and said restriction opening is controlled to regulate said blowout temperature to said target condenser blowout air temperature.

5. An air conditioner according to claim 4, wherein the rotating speed of said refrigerant compressor and said restriction opening are decreased when said signal generating means generates a signal for increasing said blowout temperature, and

the rotating speed of said refrigerant compressor and said restriction opening are increased when said signal generating means generates a signal for decreasing said blowout temperature.

6. A motor vehicle air conditioner system, comprising:

an air conditioner housing including an air inlet that receives air to be conditioned. and an air outlet for outputting conditioned air to a user environment;

an air conditioner that defines a refrigerant flow circuit through a plurality of air conditioner components, including an evaporator operatively located within the housing that cools air entering the housing through the air inlet, a compressor connected to the evaporator to compress evaporated refrigerant flowing from the evaporator, a condenser connected to the evaporator, and located within the housing, that selectively condenses refrigerant flowing from the compressor and heats air cooled by the evaporator, a heat exchanger connected to the evaporator, the compressor and the condenser and located outside of the housing, and valving located between the plurality of air conditioner components that selectively restricts refrigerant flow;

a control panel that permits a user to select an air conditioner operating mode, including a dehumidifying mode;

a plurality of air conditioner sensors that sense air conditioner operating conditions and that generate signals indicative of the sensed operating conditions;

a controller that receives the signals from the plurality of sensors, and that adjusts operating parameters of the compressor and the valving to adjust output air temperature during a dehumidification mode having dehumidification as a dominant factor; and

the controller adjusting the operating parameters of the compressor during a dehumidification mode having the output air temperature as a dominant factor, to minimize sensed output temperature overshoot and undershoot, and to minimize time needed to reach the target output air temperature;

wherein the controller further maintains the operating parameters of the valving during the dehumidification mode having the output air temperature as a dominant factor.

7. A motor vehicle air conditioner system, comprising:

an air conditioner housing including an air inlet that receives air to be conditioned, and an air outlet for outputting conditioned air to a user environment;

an air conditioner that defines a refrigerant flow circuit through a plurality of air conditioner components, including an evaporator operatively located within the housing that cools air entering the housing through the air inlet, a compressor connected to the evaporator to compress evaporated refrigerant flowing from the evaporator, a condenser connected to the evaporator, and located within the housing, that selectively condenses refrigerant flowing from the compressor and heats air cooled by the evaporator, a heat exchanger connected to the evaporator, the compressor and the condenser and located outside of the housing, and valving located between the plurality of air conditioner components that selectively restricts refrigerant flow;

a control panel that permits a user to select an air conditioner operating mode, including a dehumidifying mode;

a plurality of air conditioner sensors that sense air conditioner operating conditions and that generate signals indicative of the sensed operating conditions;

a controller that receives the signals from the plurality of sensors, and that adjusts operating parameters of the compressor and the valving to adjust output air temperature during a dehumidification mode having dehumidification as a dominant factor; and

the controller adjusting the operating parameters of the compressor during a dehumidification mode having the output air temperature as a dominant factor, to minimize sensed output temperature overshoot and undershoot, and to minimize time needed to reach the target output air temperature;

wherein the controller maintains a temperature different between air entering the evaporator and air exiting the evaporator between a predetermined temperature range and above a predetermined minimum evaporator frosting temperature during the dehumidification mode having dehumidification as a dominant factor.

8. The system of claim 7, wherein the controller maintains a temperature difference between air entering the evaporator and air exiting the evaporator between a predetermined temperature range and above a predetermined minimum evaporator frosting temperature by controlling operating parameters of the compressor and the valving.

9. A motor vehicle air conditioner system, comprising:

an air conditioner housing including an air inlet that receives air to be conditioned, and an air outlet for outputting conditioned air to a user environment;

an air conditioner that defines a refrigerant flow circuit through a plurality of air conditioner components, including an evaporator operatively located within the housing that cools air entering the housing through the air inlet, a compressor connected to the evaporator to compress evaporated refrigerant flowing from the evaporator, a condenser connected to the evaporator, and located within the housing, that selectively condenses refrigerant flowing from the compressor and heats air cooled by the evaporator, a heat exchanger connected to the evaporator, the compressor and the condenser and located outside of the housing, and valving located between the plurality of air conditioner components that selectively restricts refrigerant flow;

a control panel that permits a user to select an air conditioner operating mode, including a dehumidifying mode;

a plurality of air conditioner sensors that sense air conditioner operating conditions and that generate signals indicative of the sensed operating conditions;

a controller that receives the signals from the plurality of sensors, and that adjusts operating parameters of the compressor and the valving to adjust output air temperature during a dehumidification mode having dehumidification as a dominant factor; and

the controller adjusting the operating parameters of the compressor during a dehumidification mode having the output air temperature as a dominant factor, to minimize sensed output temperature overshoot and undershoot, and to minimize time needed to reach the target output air temperature;

wherein the controller maintains a temperature difference between air entering the evaporator and air exiting the evaporator between a predetermined temperature range and above a predetermined minimum evaporator frosting temperature by controlling operating parameters of the compressor and the valving during the dehumidification mode having conditioned air temperature as a dominant factor, after a target condenser outlet temperature is reached.

10. A motor vehicle air conditioner system, comprising:

a heat pump that conditions air according to selected user air conditioning parameters, and that outputs conditioned air to a user environment in response to a target temperature, the heat pump including both a refrigerant compressor and a flow valve connected with a plurality of heat pump components to define a refrigerant flow path circuit;

a plurality of sensors that sense heat pump operating conditions and that generate signals indicative of the sensed conditions; and

a controller that receives the signals from the plurality of sensors, and that adjusts heat pump operating parameters, including operating parameters of the both the compressor and the valve, during a sensed dehumidification dominant dehumidifying mode, and that adjusts heat pump operating parameters, including operating parameters of the compressor, while maintaining operating parameters of the valve, during a sensed temperature dominant dehumidifying mode to minimize overshoot and undershoot of a sensed output air target temperature and to minimize time needed to reach the output air target temperature.

11. A method of controlling a dehumidification mode of an air conditioner system, comprising the steps of:

sensing system-generated mode control signals to determine an operating mode;

adjusting system operating parameters, including operating parameters of a system compressor and a system valve, during a sensed dehumidification dominant dehumidifying operating mode;

adjusting system operating parameters, including operating parameters of the system compressor during a sensed temperature dominant dehumidifying mode to minimize overshoot and undershoot of a sensed output air target temperature and to minimize time needed to reach the output air target temperature; and

maintaining operating parameters of the system valve during the sensed temperature dominant dehumidifying mode, to minimize overshoot and undershoot of a sensed output air target temperature and to minimize time need to reach the out put air target temperature.

12. A method of controlling a dehumidification mode of an air conditioner system, comprising the steps of:

sensing system-generated mode control signals to determine an operating mode;

adjusting system operating parameters, including operating parameters of a system compressor and a system valve, during a sensed dehumidification dominant dehumidifying operating mode;

adjusting system operating parameters, including operating parameters of the system compressor during a sensed temperature dominant dehumidifying mode to minimize overshoot and undershoot of a sensed output air target temperature and to minimize time needed to reach the output air target temperature; and

adjusting system operating parameters, including operating parameters of the system compressor and the system valve, once the target temperature is reached in a sensed temperature dominant dehumidifying mode, to maintain conditioned air temperature above a frosting level.