Heat pump type air conditioner for vehicle

• US 5,706,664 A
• Filed: 06/03/1994
• Issued: 01/13/1998
• Est. Priority Date: 06/14/1993
• Status: Expired due to Fees

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Hara, Junichiro
• Primary Examiner(s): Ford, John K.
• Application Number:
  US08/254,048
• Time in Patent Office: 1,320 Days
• Field of Search: 62/503, 62/90, 62/176.5, 62/173, 62/159, 62/196.4, 165/240
• US Class Current: 62/159
• CPC Class Codes: B60H 1/00314 Arrangements permitting a rapid heating of the heating liquid B60H1/00492, B60H1/03 take precedence; aiding engine start by heating of engine coolants F02N19/10
• 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: F25B 43/006 Accumulators

Abstract

A heat pump type air conditioner for an automotive vehicle includes a vapor-compression refrigeration system which is provided with a compressor. An outer condenser and an inner condenser are serially connected to the compressor through a three-way valve. A bypass passage of the outer condenser communicates the compressor and the inner condenser through the three-way valve. The inner condenser is connected to an inner evaporator through an expansion valve. A refrigerant heater for heating refrigerant of the system is disposed upstream and/or downstream of the inner evaporator. The refrigerant heater is controllably operated by a control unit according to a refrigerant condition indicative signal from a refrigerant condition detector. Therefore, the air conditioner generates a sufficient heating performance even just after the start of an engine of the automotive vehicle while realizing a dehumidifying heating.

Claims

1. A heat pump type air condition for a vehicle, comprising:

refrigerant;

a compressor applying 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 a passenger compartment of the 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 and a refrigerant suction side of said compressor, 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 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 said refrigerant from said compressor to said outer heat exchanger during cooing operation and leading said refrigerant from said compressor to said heat-radiating inner heat exchanger while by passing said outer heat exchanger during heating operation;

refrigerant heating means for heating said refrigerant, said refrigerant heating means disposed to both of the refrigerant inlet side and the refrigerant outlet side of said heat-absorbing inner heat exchanger;

said refrigerant heating means including an upstream refrigerant heater which is disposed between said heat-radiating inner heat exchanger and said heat-absorbing inner heat exchanger and a downstream refrigerant heater which is disposed between said heat-absorbing inner heat exchanger and said compressor;

refrigerant condition detecting means for detecting a temperature of said refrigerant; and

control means for turning on said refrigerant heating means detected by said refrigerant condition detecting means is lower than a predetermined valve during a warm-up operation in a heating mode.

2. A heat pump type air conditioner as claimed in claim 1, wherein:

said refrigerant condition detecting means includes a heat-radiating inner heat exchanger outlet-refrigerant temperature sensor which is disposed on a conduit connected to the outlet side of said heat-radiating inner heat exchanger and a heat-absorbing inner heat exchanger inlet-refrigerant temperature sensor which is disposed between the upstream refrigerant heater and said heat-absorbing inner heat exchanger.

3. A heat pump type air conditioner for a vehicle, comprising:

refrigerant;

a compressor applying 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 a passenger compartment of the 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 and a refrigerant suction side of said compressor, 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 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 said refrigerant from said compressor to said outer heat exchanger during cooling operation and leading said refrigerant from said compressor to said heat-radiating inner heat exchanger while bypassing said outer heat exchanger during heating operation;

refrigerant heating means for heating said refrigerant, said refrigerant heating means including an upstream refrigerant heater which is disposed upstream of said heat-absorbing inner heat exchanger and a downstream refrigerant heater which is disposed downstream of said heat-absorbing inner heat exchanger;

refrigerant condition detecting means for detecting the condition of said refrigerant, said refrigerant condition detecting means including first, second, third and fourth thermal-properly detectors which are disposed at a refrigerant inlet side and a refrigerant outlet side of the upstream refrigerant heater, a refrigerant inlet side and a refrigerant outlet side of the downstream refrigerant heat, respectively; and

control means for turning on said refrigerant heating means according to the condition of said refrigerant which is detected by said refrigerant condition detecting means.