JPH08258548A - Air conditioner for automobile - Google Patents

Abstract

PURPOSE: To suppress the frosting of an external heat exchanger during heating operation at low temperature of outside air, shorten defrosting time, improve heating capacity and the reliability and the safety operation of a compressor and to make energy-saving operation possible without impairing amenity in a cabin by making two kinds of fluids flow separately in the external heat exchanger. CONSTITUTION: An aluminum pipe (or copper pipe) 17 is inserted in laminated fins 16. At the heating time, low-temperature low-pressure refrigerant, and cooling liquid receiving heat by cooling a heating component such as a driving motor, flow separately while meandering and intersecting in the aluminum pipe (or copper pipe) 17 from the lower part of an external heat exchanger 14 toward the upper part. It is desirable to determine the flowing way of each fluid by frosting state, a defrosting state and the setting of pass balance for maintaining air-conditioning and heating performance to the maximum. As a result, the low-temperature low-pressure refrigerant and cooling liquid can be heat-exchanged through metal with high heat conductivity as a medium, so that heat exchange efficiency can be kept high.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner mainly used in electric vehicles.

[0002]

2. Description of the Related Art FIG. 3 is a refrigeration cycle diagram of a heat pump system showing a conventional example. As a basic driving state,
During the cooling operation, the refrigerant gas discharged from the hermetic electric compressor 1 (hereinafter referred to as the compressor 1) passes through the four-way valve 2, is condensed in the outdoor heat exchanger 3, and is decompressed in the electric expansion valve 4 to be the indoor heat exchanger. It evaporates at 5, and returns to the compressor 1 through the four-way valve 2 and the accumulator 6. During the heating operation, the refrigerant gas discharged from the compressor 1 passes through the four-way valve 2, is condensed in the indoor heat exchanger 5, is decompressed by the electric expansion valve 4, is evaporated in the outdoor heat exchanger 3, and is closed by the four-way valve 2. , And returns to the compressor 1 through the accumulator 6.

FIG. 4 is a cooling cycle diagram of heat generating components such as a drive motor 7 of an electric vehicle showing a conventional example. A fluid pump including a drive motor 7 for an electric vehicle, a motor controller 8 of the drive motor 7, a DC / DC converter 9, heat-generating components such as an inverter 10 for an air conditioner, a fluid pump 11 and a heat exchanger 12. A drive motor 7, a motor controller 8, a DC / DC converter 9, and a cycle for circulating a cooling liquid for cooling heat-generating components such as an air conditioner inverter 10 are constituted by 11, and heat dissipation of the cooling liquid is dedicated to heat exchange. Performed with the outside air by the vessel 12.

The heat generated in each functional part of the electric vehicle is radiated to the outside air, and as a heat source during heating operation,
Currently, it is not used efficiently.

[0005]

However, if the outside air temperature becomes about 5 ° C. or less in the normal refrigerating cycle, it is possible to exchange heat with the outside air during the heating operation to extract heat.
Frost starts on the outdoor heat exchanger 3, and the amount of airflow and heat exchange capacity are reduced due to the growth of frost, which reduces the heating capacity, and therefore it is necessary to perform the defrosting operation.

When the discharged gas is allowed to flow to the outdoor heat exchanger 3 for defrosting, cool air is blown into the room during the defrosting period, which deteriorates comfort.

In addition, it is also an important issue to quickly remove the fog generated on the windshield of the vehicle during the defrosting of the outdoor heat exchanger 3 from the viewpoint of safety.

Further, even after the defrosting is completed and the heating cycle is restored, it takes a long time to return to the stable operation state, and the comfort state continues to be impaired.

In addition, the battery capacity of an electric vehicle is limited, and it is an important subject to suppress the amount of power used and ensure comfort.

The present invention suppresses frost formation on the outdoor heat exchanger 3 even during heating operation at low outside air temperature, suppresses defrosting time as short as possible, improves heating capacity and reliability of the hermetic electric compressor 1. And improve driving safety, without compromising indoor comfort,
The purpose is to perform energy saving operation.

[0011]

Therefore, a first means of the present invention is to provide a hermetic electric compressor having an electric motor section and a compressor section in a hermetic container, a four-way valve, an outdoor heat exchanger, and an expansion unit. In a heat pump type refrigeration cycle equipped with a valve and an indoor heat exchanger as main components, a first passage through which the first fluid flows and a second passage through which the second fluid flows inside the outdoor heat exchanger. Shall be provided.

The second means of the present invention is, in addition to the first means, at least a drive motor for an electric vehicle, a controller of the drive motor, and a heat-generating component of any one of an inverter for an air conditioner. A fluid pump is provided, and a cycle for circulating a fluid that cools at least one heat-generating component of the drive motor, the motor controller, and the air conditioner inverter is constituted by the fluid pump, and heat dissipation of the fluid is performed. The outdoor heat exchanger shall be used.

A third means of the present invention is, in addition to the first means, at least a drive motor for an electric vehicle, a controller for the drive motor, and a heat-generating component for any one of an inverter for an air conditioner, A fluid pump and a heat exchanger are provided, and the fluid pump constitutes a cycle for circulating a fluid for cooling at least one heat-generating component of the drive motor, the motor controller, and the air conditioner inverter. Depending on the operating state of the cycle, at least during the cooling operation, the heat is radiated by the heat exchanger, and during the heating operation, the heat is radiated by the outdoor heat exchanger.

[0014]

According to the first and second means of the present invention, since two or more kinds of fluids are separately flowed through the inside of the outdoor heat exchanger, for example, a low-temperature low-pressure refrigerant and a cooling liquid for a heat-generating component such as a drive motor. Since heat exchange with a metal can be performed by using a metal with high thermal conductivity as a medium and the heat exchange efficiency can be kept high, it can be effectively used as a heat source for a heat pump during heating and can be worn even when the outside temperature is low. Hard to frost.

According to the third means of the present invention, the heat of the cooling liquid of the heat-generating component such as the drive motor exchanges heat with the low-temperature low-pressure refrigerant during the heating operation, and the dedicated heat exchanger during the cooling operation. Can exchange heat with the outside air.

Further, since it is difficult to form frost and the defrosting time can be shortened as much as possible, it is possible to quickly start up to a steady operation state, so that it is possible to prevent clouding of the windshield of the vehicle as much as possible.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An automobile air conditioner according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a heat pump system for an automobile air conditioner according to the present invention. At the time of heating operation, the two-way valves 13a and 13b are operated to cool the heat-generating components such as the drive motor 7 and receive the cooling liquid. Pour into the exchanger 14. Since two different kinds of fluids are allowed to flow inside the outdoor heat exchanger 14, heat exchange between the low-temperature low-pressure refrigerant and the cooling liquid can be performed using a metal having a high thermal conductivity as a medium, and the heat exchange efficiency can be improved. Since it can be kept high, the cooling liquid can be efficiently used as a heat source for the heat pump during heating.

Further, since the cooling liquid warmer than the outside air is always flown into the outdoor heat exchanger 14 during the heating operation, it is difficult to frost even when the outside air temperature is low.

Further, since the defrosting time can be shortened as much as possible, it is possible to quickly start up to a steady operation state, so that it is possible to prevent clouding of the windshield of the vehicle as much as possible.

Further, since the time until stable heating operation of the compressor 1 can be shortened, energy saving operation can be performed especially in a vehicle having a limited battery power capacity such as an electric vehicle.

Further, since the low pressure does not easily drop during the heating operation and the circulation amount does not decrease, the refrigerating machine oil returns well and the compressor 1
The reliability can be secured without impairing the lubricity of the.

Further, at the time of cooling operation, two three-way valves 13 are provided.
By operating a and b, the heat of the cooling liquid of the heat-generating components such as the drive motor 7 is exchanged with the outside air by the dedicated heat exchanger 15, so that the capacity of the outdoor heat exchanger 14 is not reduced and the heat is consumed. It is possible to exhibit sufficient cooling capacity without increasing the power.

FIG. 2 shows the structure of the fin & tube type outdoor heat exchanger 14 of the air conditioner for an automobile, which is an example of the present invention, and the flow direction of the fluid. An aluminum tube 17 is inserted in the laminated fin 16. As a basic fluid flow, at the time of heating, a low-temperature low-pressure refrigerant and the drive motor 7
The cooling liquid that has cooled the heat-generating components such as the above and received heat flows through the aluminum pipe 17 from the lower part of the outdoor heat exchanger 14 toward the upper part,
Flow separately while meandering and intersecting. It is desirable that the way of flowing each fluid is determined by the frosting state, the defrosting state, and the setting of the path balance for keeping the cooling and heating performance at the maximum.

The outdoor heat exchanger 14 is a fin &
The structure is not limited to the tube type, and may be a multi-flow type or a serpent type.

The cooling liquid may be a general antifreezing liquid or oil for vehicles, and the tube of the outdoor heat exchanger 14 may be a copper pipe.

The system control method of the present invention can be applied to a cycle having a dehumidifying function other than the present embodiment, a heating cycle not using a four-way valve, etc., based on the embodiment of the present invention.

[0028]

As is apparent from the above description, the present invention suppresses the frost formation on the outdoor heat exchanger even during the heating operation at a low outdoor temperature, suppresses the defrosting time as short as possible, and improves the heating capacity. And, the reliability of the compressor and the safety during operation can be improved, and energy saving operation can be performed without impairing indoor comfort.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram of a heat pump system showing an embodiment of the present invention.

FIG. 2 is a configuration diagram of an outdoor heat exchanger showing one embodiment of the present invention.

FIG. 3 is a refrigeration cycle diagram of a heat pump system showing a conventional example.

FIG. 4 is a cooling cycle diagram of a drive motor of an electric vehicle showing a conventional example.

[Explanation of symbols]

 1 Hermetic Electric Compressor 2 Four-way Valve 3 Outdoor Heat Exchanger 4 Electric Expansion Valve 5 Indoor Heat Exchanger 6 Accumulator 7 Drive Motor 8 Motor Controller 9 DC / DC Converter 10 Air Conditioner Inverter 11 Fluid Pump 12 Heat Exchanger 13a Three-way Valve 13b Three-way valve 14 Outdoor heat exchanger 15 Heat exchanger 16 Fin 17 Aluminum tube

Claims (3)

[Claims] 1. A hermetically sealed electric compressor having an electric motor section and a compressor section in a hermetically sealed container, a four-way valve, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger as main parts. In a heat pump type refrigeration cycle, an air conditioner for a vehicle, wherein a first passage through which a first fluid flows and a second passage through which a second fluid flows are provided inside the outdoor heat exchanger. 2. A drive motor for an electric vehicle, a controller for the drive motor, a heat-generating component of any one of an inverter for an air conditioner, and a fluid pump, the fluid pump and the drive motor. The vehicle air conditioner according to claim 1, wherein a cycle for circulating a fluid that cools at least one heat-generating component of the motor controller and the air conditioner inverter is performed, and heat dissipation of the fluid is performed by an outdoor heat exchanger. . 3. A drive motor for an electric vehicle, a controller for the drive motor, a heat-generating component of any one of an inverter for an air conditioner, a fluid pump and a heat exchanger, and at least the above-mentioned fluid pump. A drive motor, the motor controller, and a cycle that circulates a fluid that cools at least one heat-generating component of the air conditioner inverter, and radiates the fluid at least during cooling operation depending on the operating state of the refrigeration cycle. The air conditioner for a vehicle according to claim 1, wherein control is performed by the heat exchanger, and heat dissipation of the fluid is performed by the outdoor heat exchanger during heating operation.