Automotive air conditioner having condenser and evaporator provided within air duct

• US 5,685,162 A
• Filed: 11/30/1994
• Issued: 11/11/1997
• Est. Priority Date: 04/26/1991
• Status: Expired due to Term

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Inventors: Suzuki, Takahisa, Fujiwara, Kenichi, Yamanaka, Yasushi, Sanada, Ryoichi, Iritani, Kunio, Suzuki, Nobunao, Honda, Keita, Numazawa, Shigeo, Isaji, Akira
• Primary Examiner(s): Wayner, William E.
• Application Number:
  US08/352,110
• Time in Patent Office: 1,077 Days
• Field of Search: 62/156, 62/90, 62/173
• US Class Current: 62/156
• CPC Class Codes: B60H 1/00021 Air flow details of HVAC devices
• CPC Class Codes: B60H 1/00385 for vehicles having an electrical drive, e.g. hybrid or fuel cell
• CPC Class Codes: B60H 1/00392 for electric vehicles having only electric drive means
• CPC Class Codes: B60H 1/00814 Control systems or circuits characterised by their output, for controlling particular components of the heating, cooling or ventilating installation
• CPC Class Codes: B60H 1/00878 the components being temperature regulating devices
• CPC Class Codes: B60H 1/00914 where the flow direction of the refrigerant does not change and there is a bypass of the condenser
• CPC Class Codes: B60H 1/00921 where the flow direction of the refrigerant does not change and there is an extra subcondenser, e.g. in an air duct
• 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 1/321 for preventing the freezing of a heat exchanger
• CPC Class Codes: B60H 1/3211 for increasing the efficiency of a vehicle refrigeration cycle
• CPC Class Codes: B60H 2001/00935 comprising four way valves for controlling the fluid direction
• CPC Class Codes: B60H 2001/00961 comprising means for defrosting outside heat exchangers
• CPC Class Codes: B60H 2001/3248 related to pressure
• CPC Class Codes: B60H 2001/3251 of the refrigerant at a condensing unit
• CPC Class Codes: B60H 2001/3254 of the refrigerant at an expansion 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 2001/326 of the refrigerant at a condensing unit
• CPC Class Codes: B60H 2001/3261 : of the air at an evaporating unit
• CPC Class Codes: B60H 2001/327 : related to a compressing unit
• 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: B60H 2001/3288 : Additional heat source
• CPC Class Codes: B60H 2001/3292 : Compressor drive is electric only
• CPC Class Codes: F25B 13/00 : Compression machines, plants or systems, with reversible cycle defrosting cycles F25B47/02
• CPC Class Codes: F25B 2313/023 : using multiple indoor units
• CPC Class Codes: F25B 2313/02343 : during dehumidification
• CPC Class Codes: F25B 2313/025 : using multiple outdoor units
• CPC Class Codes: F25B 2313/0272 : using bridge circuits of one-way valves
• CPC Class Codes: F25B 2313/02741 : using one four-way valve
• CPC Class Codes: F25B 2339/044 : Condensers with an integrated receiver
• CPC Class Codes: F25B 2339/0446 : characterised by the refrigerant tubes connecting the header of the condenser to the receiver; Inlet or outlet connections to receiver
• CPC Class Codes: F25B 2500/01 : Geometry problems, e.g. for reducing size
• CPC Class Codes: F25B 39/04 : Condensers
• CPC Class Codes: F25B 49/027 : Condenser control arrangements

Abstract

The evaporator and the condenser are disposed in a duct. First bypass passage is disposed at the side of the condenser and first air mixing damper rotates to control air bypassing amount. Further second bypass passage is formed at the side of the evaporator and second mixing damper rotates to control air bypassing amount. Cooling rate at the evaporator and heating rate at the condenser are varied so that air adjusted in proper temperature is generated and discharged from each outlets into a room. An outside heat exchanger is disposed the outside of the duct. Refrigerant flow is randomly switched among the outside heat exchanger, the evaporator and the condenser so that cooling, heating, dehumidifying, dehumidified-heating and defrosting operations are performed.

Claims

1. An automotive air conditioner, comprising:

a duct defining a passageway for air to a room of an automobile;

a blower for blasting air into the room of the automobile by way of said duct;

an evaporator disposed in the inside of said duct for causing refrigerant to exchange heat with air to be sent into the room of the automobile;

a heater disposed on the downstream of said upstream side heat exchanger in said duct for causing refrigerant to exchange heat with air to be sent into the room of the automobile;

an outside heat exchanger disposed outside said duct for causing air outside the room and refrigerant to exchange heat with each other;

heat being taken from air in said evaporator to evaporate refrigerant while heat is exchanged between refrigerant of a high temperature and air in said heater so that dehumidifying operation wherein heating of air is performed;

flow passage changing over means for changing over the condition of said outside heat exchanger upon dehumidifying operation from a condition wherein said outside heat exchanger is not used as a heat exchanger between refrigerant and air or said outside heat exchanger is used as a refrigerant condenser to another condition wherein said outside heat exchanger is used as a refrigerant evaporator;

a frosting sensor for detecting a frosted condition of said evaporator; and

controlling means for controlling, when a frosted condition of said evaporator is forecast or detected by said frosting sensor upon dehumidifying operation, said flow passage changing over means to change over the condition of said outside heat exchanger upon dehumidifying operation from the condition wherein said outside heat exchanger is not used as a heat exchanger between refrigerant and air or said outside heat exchanger is used as a refrigerant condenser to the condition wherein said outside heat exchanger is used as a refrigerant evaporator.

2. An automotive air conditioner, comprising:

a duct defining a passageway for air to a room of an automobile;

a blower for blasting air into the room of the automobile by way of said duct;

an evaporator disposed in the inside of said duct for cooling the air by evaporating refrigerant;

a heater disposed on the downstream of said evaporator;

an outside heat exchanger disposed outside said duct for causing air outside the room and refrigerant to exchange heat with each other;

an expanding means for expanding and decompressing refrigerant;

a changing over means for switching refrigerant flow to said evaporator, said heater and said outside heat exchanger, said changing over means switching at least among a heating operation wherein refrigerant circulates in the order of said compressor, said heater, said expanding means and said outside heat exchanger, a first dehumidifying operation wherein refrigerant circulates in the order of said compressor, said heater, said expanding means, said outside heat exchanger and said evaporator, a second dehumidifying operation and defrosting operations wherein refrigerant circulates said compressor, said heater, said outside heat exchanger, said expanding means and said evaporator;

a control means for controlling said change over means in such a manner that when one of said second dehumidifying operation and defrosting operation changes into said heating operation, said first dehumidifying operation is performed for a predetermined time before changing and then said heating operation is performed.

3. An automotive air conditioner according to claim 2, wherein said compressor varies its discharge capacity based on a signal generated from said control means, said outside heat exchanger has a blower which forcedly blows air thereto and is controlled by said control means, said control means changes between said first dehumidifying operation and said second dehumidifying operation and controls air amount generated by said blower for said outside heat exchanger in response to one of refrigerant pressure and temperature at a suction side or a discharge side of said compressor.

4. An automotive air conditioner according to claim 3, wherein when said control means performs dehumidifying operation under the condition such that one of refrigerant pressure and temperature at discharge side of said compressor is high and one of refrigerant pressure and temperature at suction side of said compressor is also high, said control means selects said second dehumidifying operation and increases air amount generated by said blower for said outside heat exchanger, and performs when said control means performs dehumidifying operation under the condition such that one of refrigerant pressure and temperature at discharge side of said compressor is low and one of refrigerant pressure and temperature at suction side of said compressor is also low, said control means selects said first dehumidifying operation and increases air amount generated by said blower for said outside heat exchanger.

5. An automotive air conditioner according to claim 4, wherein when said control means performs dehumidifying operation under the condition such that one of refrigerant pressure and temperature at discharge side of said compressor is high and one of refrigerant pressure and temperature at suction side of said compressor is low, said control means selects said second dehumidifying operation, decreases the capacity of said compressor and decreases air amount generated by said blower for said outside heat exchanger, and when said control means performs dehumidifying operation under the condition such that one of refrigerant pressure and temperature at discharge side of said compressor is low and one of refrigerant pressure and temperature at suction side of said compressor is high, said control means selects said first dehumidifying operation, increases the capacity of said compressor and decreases air amount generated by said blower for said outside heat exchanger.