Heat pump type air conditioner for automotive vehicle

• US 5,331,823 A
• Filed: 04/20/1993
• Issued: 07/26/1994
• Est. Priority Date: 04/20/1992
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Matsuoka, Takayoshi
• Primary Examiner(s): Wayner, William E.
• Application Number:
  US08/048,172
• Time in Patent Office: 462 Days
• Field of Search: 454/93, 454/75, 165/43, 236/91 C, 62/209, 62/243, 62/196.4, 62/173
• US Class Current: 62/173
• CPC Class Codes: B60H 1/00007 Combined heating, ventilating, or cooling devices control systems or mechanisms B60H1/00642
• CPC Class Codes: B60H 1/00878 the components being temperature regulating devices
• CPC Class Codes: G05D 23/1917 using digital means
• CPC Class Codes: G05D 23/20 with sensing elements having variation of electric or magnetic properties with change of temperature G05D23/13 takes precedence

Abstract

A heat pump type air conditioner for an automotive vehicle has a compressor to which an outer heat exchanger and a heat-radiating inner heat exchanger are connected through a three-way valve. The heat-radiating inner heat exchanger is connected to a heat-absorbing inner heat exchanger through an expansion valve. The heat-absorbing inner heat exchanger is connected to the compressor. During a cooling operation the three-way valve is set to lead the refrigerant from the compressor to the outer heat exchanger. 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 outer heat exchanger. The three-way valve is switched by a switching means when a target conditioned-air temperature, which is determined according to thermal information of the automotive vehicle, generally corresponds to a temperature at which clouding of windows is not caused by the relationship between a compartment temperature and an ambient temperature. Accordingly, the cooling and heating operations are stably implemented without being effected by various conditions, and the clouding of the windows is securely prevented while electric power consumption is deceased.

Claims

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

refrigerant;

a compressor applying a workload to said refrigerant;

an outer heat exchanger 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;

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

a switching device connecting said compressor with said outer heat exchanger and said heat-radiating inner heat exchanger, said switching device being set at one of a first state in that said compressor is fluidly communicated with said outer heat exchanger and a second state in that said compressor is fluidly communicated with said heat-radiating inner heat exchanger; and

a control unit communicated with said switching device, said control unit selectively controlling the state of said switching device such that a temperature of air fed into the passenger compartment is controlled at a temperature at which clouding of vehicle windows is avoided and which temperature is determined from the relationship between a real compartment temperature and a real ambient temperature.

2. A heat pump type air conditioner as claimed in claim 1, wherein said compressor is of a variable displacement type in which input power is directly variable.

3. A heat pump type air conditioner as claimed in claim 1 further comprising an air mixing door which is disposed upstream of said heat-radiating inner heat exchanger so as to variably change air flow amount passing through said heat-radiating inner heat exchanger.

4. A heat pump type air conditioner as claimed in claim 1, further comprising a plurality of sensors for detecting thermal condition of the vehicle.

5. A heat pump type air conditioner as claimed in claim 4, wherein said control unit has means for selecting a temperature at which clouding or fogging of windows of the automotive vehicle is avoided, in accordance with the thermal condition.

6. A heat pump type air conditioner for an automotive vehicle, said air conditioner controlling a condition of a passenger compartment of the automotive vehicle by its cooling and heating operations, said air conditioner comprising:

refrigerant;

a compressor applying a workload to said refrigerant;

an outer heat exchanger 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;

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

a switching valve disposed among the refrigerant discharge side of said compressor, a refrigerant inlet side of said outer heat exchanger and a refrigerant inlet side of said heat-radiating inner heat exchanger, said switching valve leading the refrigerant from said compressor to said outer heat exchanger during the cooling operation, said switching valve leading said refrigerant to said heat-radiating inner heat exchanger without leading to said outer heat exchanger during the heating operation; and

a control unit communicated with said switching valve, said control unit controlling said switching valve so as to implement a switching between the cooling and heating operations when a target outlet air temperature according to thermal information of the automotive vehicle generally corresponds to a boundary temperature which does not cause clouding of windows of the automotive vehicle and which temperature is determined from the relationship between a compartment temperature and an ambient temperature.

7. A heat pump type air conditioner for an automotive vehicle, said air conditioner controlling a condition of a passenger compartment of the automotive vehicle by its cooling and heating operations, said air conditioner comprising:

refrigerant;

a compressor applying a workload to said refrigerant;

an outer heat exchanger 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;

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

a switching valve disposed among the refrigerant discharge side of said compressor, a refrigerant inlet side of said outer heat exchanger and a refrigerant inlet side of said heat-radiating inner heat exchanger, said switching valve leading the refrigerant from said compressor to said outer heat exchanger during the cooling operation, said switching valve leading said refrigerant to said heat-radiating inner heat exchanger without leading it to said outer heat exchanger during the heating operation; and

a means for primarily setting an outlet air temperature from said heat-absorbing inner heat exchanger within an area which is lower than an upper limit temperature does not cause which clouding or fogging of windows of the automotive vehicle and which temperature is determined from the relationship between a real compartment temperature and an ambient temperature, and which area is higher than a lower limit temperature at which said heat-absorbing inner heat exchanger is frozen, during the heating operation.

8. A heat pump type air conditioner for an automotive vehicle, said air conditioner controlling a condition of a passenger compartment of the automotive vehicle by its cooling and heating operations, said aid conditioner comprising:

a compressor;

a three-way valve connected to said compressor;

an outer condenser connected to said three-way valve;

an inner condenser connected to said three-way valve and said outer condenser;

an expansion valve connected to said inner condenser;

an evaporator connected to said expansion valve and said compressor; and

refrigerant circulating a circuit constituted by said compressor, said three-way valve, said outer condenser, said inner condenser, said expansion valve and said evaporator;

wherein said three-way valve fluidly communicates said compressor and said outer condenser during the cooling operation and communicates said compressor and said inner condenser while fluidly isolating said outer condenser during the heating operation, a state of said three-way valve being changed from a state in the cooling operation to a state in the heating operation when a target conditioned-air temperature according to thermal information of the automotive vehicle corresponds to a boundary temperature which does not caused clouding of windows of the automotive vehicle and which boundary temperature is determined from the relationship between a compartment temperature and an ambient temperature.