Heat pump type air conditioner for automotive vehicle

• US 5,355,689 A
• Filed: 05/25/1993
• Issued: 10/18/1994
• Est. Priority Date: 05/25/1992
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Hara, Junichiro, Matsuoka, Takayoshi
• Primary Examiner(s): Wayner, William E.
• Application Number:
  US08/066,265
• Time in Patent Office: 511 Days
• Field of Search: 62/196.4, 62/117, 62/159, 62/173, 62/90, 62/176.5, 165/43, 236/75
• US Class Current: 62/159
• 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 1/3207 for minimizing the humidity of the air
• CPC Class Codes: F25B 6/04 arranged in series

Abstract

A heat pump type air conditioner for an automotive vehicle has a compressor whose outlet is connected to a condenser and a heat-radiating inner heat exchanger through a three-way valve. The heat-radiating inner heat exchanger is connected to an evaporator through an expansion valve. The evaporator is connected to an inlet of the compressor. During a cooling operation, the three-way valve is set to lead the refrigerant from the compressor to the condenser. During a heating operation, the three-way valve is set to lead the refrigerant from the compressor to the heat-radiating inner heat exchanger while bypassing the condenser. A control unit controls such that a cooling efficiency of the condenser is lowered for a predetermined time when the compressor is started. Therefore, the heating operation is securely implemented, and a start-up period in starting is shortened. Furthermore, the freezing of the condenser is avoided.

Claims

1. A heat pump type air conditioner for an automotive vehicle, comprising:

refrigerant;

a compressor applying a workload to said refrigerant;

a condenser connected to a refrigerant discharge side of said compressor and radiating heat of said refrigerant into ambient air;

a blower leading air for air-conditioning the passenger compartment of the automotive vehicle;

a heat-radiating inner heat exchanger connected to the refrigerant discharge side of said compressor and transmitting the heat of said refrigerant to the air led by said blower;

an expansion valve connected to a refrigerant outlet side of said heat-radiating inner heat exchanger;

an evaporator connected to a refrigerant outlet side of said expansion valve, said evaporator transmitting the heat of the air led by said blower to said refrigerant which is supplied through said expansion valve from at least one of said condenser and said heat-radiating inner heat exchanger;

a switching device disposed among the refrigerant discharge side of said compressor, said switching device being set at one of a first state in that said compressor is fluidly communicated with said condenser and a second state in that said compressor is fluidly communicated with said heat-radiating inner heat exchanger; and

means for lowering a cooling efficiency of said evaporator for a predetermined time when said compressor is started.

2. A heat .pump type air conditioner as claimed in claim 1, wherein said means for lowering a cooling efficiency for a predetermined time includes means for lowering an inlet air flow rate to said heat-radiating inner heat exchanger for a predetermined time.

3. A heat pump type air conditioner as claimed in claim 1, wherein said means for lowering a cooling efficiency for a predetermined time includes a means for raising the inlet air temperature of said heat-radiating inner heat exchanger for a predetermined time so as to be higher than the outlet air temperature of said evaporator.

4. A heat pump type air conditioner as claimed in claim 1, wherein said means for lowering a cooling efficiency for a predetermined time includes means for raising the inlet air temperature of said evaporator for a predetermined time.

5. A heat pump type air conditioner as claimed in claim 1, wherein said means for lowering cooling efficiency for a predetermined time includes means for decreasing the opening degree of said expansion valve for a predetermined time.

6. A heat pump type air conditioner for an automotive vehicle, comprising:

refrigerant;

a compressor applying a workload to said refrigerant;

a condenser connected to a refrigerant discharge side of said compressor and radiating heat of said refrigerant into ambient air;

a blower leading air for air-conditioning the passenger compartment of the automotive vehicle;

a heat-radiating inner heat exchanger connected to the refrigerant discharge side of said compressor and transmitting the heat of said refrigerant to the air led by said blower;

an expansion valve connected to a refrigerant outlet side of said heat-radiating inner heat exchanger;

an evaporator connected to a refrigerant outlet side of said expansion valve, said evaporator transmitting the heat of the air led by said blower to said refrigerant which is supplied through said expansion valve from at least one of said condenser and said heat-radiating inner heat exchanger;

a switching device disposed among the refrigerant discharge side of said compressor, said switching device being set at one of a first state in that said compressor is fluidly communicated with said condenser and a second state in that said compressor is fluidly communicated with said heat-radiating inner heat exchanger;

air flow rate changing means changing flow rate of the air fed into said heat-radiating inner heat exchanger;

thermal information detecting means detecting at least one of thermal information of said refrigerant and thermal information of the automotive vehicle inside and outside;

process selecting means dividing the heating operation into plural processes which have different heating properties, respectively, said process selecting means selecting one of the process on the basis of the thermal information detected by said thermal information detecting means; and

air flow rate controlling means variably controlling said air flow rate changing means on the basis of said selected process and the detected thermal information.

7. A heat pump type air conditioner as claimed in claim 6, wherein said thermal information detecting means detects a correlation amount to high-pressure side of refrigeration cycle and a correlation amount to low-pressure side of the refrigeration cycle, said air flow rate controlling means variably controlling said air flow rate changing means on the basis of the low-pressure side correlation amount during a process selected by said process selecting means, and said air flow rate control means controlling said air flow rate changing means on the basis of the high-pressure side correlation amount during a process except of the process selected by said process selecting means.

8. A heat pump type air conditioner as claimed in claim 7, wherein said air flow rate controlling means uses a temperature of the air passing through said heat-radiating inner heat exchanger as the high-pressure side correlation amount and uses a temperature of the air passing through said evaporator as the low-pressure side correlation amount.

9. A heat pump type air conditioner as claimed in claim 8, wherein said air flow rate controlling means defines a minimum value of the air flow rate to said heat-radiating inner heat exchanger.

10. A heat pump type air conditioner as claimed in claim 9, wherein said air flow rate changing means includes inlet air flow rate changing means which changes flow rate of the air fed by said blower and ratio changing means which changes a ratio of air fed to said heat-radiating inner heat exchanger relative to the air fed by said blower, and said air flow rate control means defining a minimum value of the air flow rate changed by the inlet air flow rate changing means and a minimum value of the ratio changed by the ratio changing means.

11. A heat pump type air conditioner as claimed in claim 6, wherein said thermal information detecting means detects thermal information applied to a first process and thermal information applied to a second process when the operation moves from the first process to the second process wherein the first and second processes continuously operated, and said air flow rate controlling means gradually changing a controlled state of said air flow rate changing means on the basis of the thermal information applied to the first and second processes.

12. A heat pump type air conditioner as claimed in claim 6, wherein said air flow rate controlling means defines an initial air flow rate of the air flowing into said heat-radiating inner heat exchanger on the basis of the thermal information detected at the start of said compressor.

13. A heat pump type air conditioner for an automotive vehicle, comprising:

refrigerant;

a compressor applying a workload to said refrigerant;

a condenser connected to a refrigerant discharge side of said compressor and radiating heat of said refrigerant into ambient air;

a blower leading air for air-conditioning the passenger compartment of the automotive vehicle;

a heat-radiating inner heat exchanger connected to the refrigerant discharge side of said compressor and transmitting the heat of said refrigerant to the air led by said blower;

an expansion valve of a variable opening degree type connected to a refrigerant outlet side of said heat-radiating inner heat exchanger;

an evaporator connected to a refrigerant outlet side of said expansion valve, said evaporator transmitting the heat of the air led by said blower to said refrigerant which is supplied through said expansion valve from at least one of said condenser and said heat-radiating inner heat exchanger;

a switching device disposed among the refrigerant discharge side of said compressor, a refrigerant inlet side at said condenser and a refrigerant inlet side of said heat-radiating inner heat exchanger, said switching device being set at one of a first state in that said compressor in fluidly communicated with said condenser and a second state in that said compressor is fluidly communicated with said heat-radiating inner heat exchanger;

thermal information detecting means detecting at least one of thermal information of said refrigerant and thermal information of the automotive vehicle inside and outside; and

expansion valve controlling means controlling an opening degree of said expansion valve on the basis of the detected thermal information such that the flow rate of said refrigerant is maintained to be larger than a predetermined value and such that the opening degree of said expansion valve is greater than zero at warm-up or start-up of a heating operation.

14. A heat pump type air conditioner as claimed in claim 13, wherein said thermal information detecting means includes a detector which detects a correlation amount of a low-pressure side in refrigeration cycle.

15. A heat pump type air conditioner as claimed in claim 14, further comprising means for heating the detector according to the amount relation with the low pressure side in the refrigeration cycle.

16. A heat pump type air conditioner as claimed in claim 13, wherein said expansion valve includes an electromagentic expansion valve which is able to vary its opening degree according to the thermal information detected by said thermal information detecting means.

17. A heat pump type air conditioner as claimed in claim 16 wherein said expansion valve controlling means uses at least one of the air temperature of air passing through said heat-radiating inner heat exchanger and the air temperature of air passing through said evaporator as the basis for controlling the opening degree of said expansion valve.