JPH0330161Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a vehicle air conditioning system that cools and heats the inside of a vehicle using a heat pump.

(Prior Art) Conventionally, the one shown in FIG. 3 is known as a vehicle air conditioning system capable of heating and cooling.

This vehicle air conditioning system includes a refrigeration circuit consisting of an evaporator 3, a compressor 4, a condenser 5, and an expansion valve 6. The evaporator 3 is disposed in a passage 1, and engine cooling water is circulated. A heater core 7 is arranged within the passage 1.

When this air conditioning system cools the interior of the vehicle, the refrigeration circuit is activated, the air taken in by the blower 2 from the opening at one end of the passage 1 is cooled by the evaporator 3, and the cooled air is sent into the vehicle interior. are doing. In addition, when heating the vehicle interior, the operation of the refrigeration circuit is stopped, the engine cooling water is circulated through the heater core 7, and the air taken in by the blower 2 from the opening at one end of the passage 1 is passed through the heater core 7. The heated air is then sent into the vehicle interior.

However, in the above-mentioned vehicle air conditioning system, even if an attempt is made to heat the vehicle interior immediately after the engine starts operating in winter when the outside temperature is low, the engine and the engine cooling water are not sufficiently heated, so the heater core 7 does not have a heat dissipation effect. The problem was that it took a long time to warm up the interior of the vehicle.

In view of the above circumstances, an air conditioning system that can quickly heat the interior of a vehicle even immediately after the engine starts operating has been proposed in Japanese Patent Laid-Open No. 59-38113.

In this vehicle air conditioning system, a heat pump is configured by a compressor driven by an engine, a heat exchanger, a receiver, an expansion valve, and an evaporator, and an air duct is provided adjacent to the engine exhaust pipe. A rotary heat exchanger is disposed in communication with the air duct and the exhaust pipe, and the evaporator is disposed in the air duct on the downstream side of the rotary heat exchanger.

In this vehicle air conditioning system, during heating operation, the refrigerant discharged from the compressor is passed through the heat exchanger, receiver, expansion valve, and evaporator in this order, while the rotary heat exchanger is rotated to collect the exhaust heat from the exhaust gas. It is guided to the evaporator side to promote endothermic action in the evaporator.

In this vehicle air conditioning system, the heat pump can be effectively operated to quickly warm the interior of the vehicle even immediately after the engine starts operating.

(Problem that the invention aims to solve) However, in conventional vehicle air conditioning systems that use heat pumps, an air duct is provided adjacent to the exhaust pipe, and a rotary heat exchanger is installed between the air duct and the exhaust pipe. Since the rotary heat exchanger needs to be placed in the same position, the structure of the rotary heat exchanger part in particular is complicated, making installation work extremely troublesome, and it also requires a large space for installation.

In addition, when the engine is running, exhaust gas is constantly in contact with the rotary heat exchanger, and some exhaust gas flows into the evaporator through the rotary heat exchanger. The drawback is that foreign matter such as soot may adhere to the exchanger and evaporator, or corrosion may occur, which may impede heat exchange.

This invention was made in view of the above problems,
The purpose is not only to be able to quickly warm up the cabin even immediately after the engine starts running, but also to have a simple configuration that is advantageous for retrofitting work, and to avoid corrosion of the heat exchanger that exchanges heat with exhaust gas. It is an object of the present invention to provide a heat pump type vehicle air conditioning system that can perform heating using exhaust heat satisfactorily over a long period of time without causing problems such as the following.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention aims to transfer refrigerant discharged from a compressor driven by an engine to an indoor heat exchanger, an expansion valve, and an indoor heat exchanger via a four-way switching valve. a heating cycle that circulates in order of an external heat exchanger;
In a vehicle air conditioning system equipped with a heat pump that can be operated in a cooling cycle in which refrigerant discharged from a compressor is passed through a four-way switching valve in order of an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger. , an expansion valve whose opening degree can be controlled electrically is used as an expansion valve, and an exhaust gas heat exchanger for recovering exhaust gas heat is attached to the outside of the engine exhaust pipe, and the refrigerant intake side of the exhaust gas heat exchanger is attached to the outside of the engine exhaust pipe. is connected to the connection midpoint between the indoor heat exchanger and the expansion valve via the switching valve, and the refrigerant discharge side of the exhaust gas heat exchanger is connected to the connection midpoint between the outdoor heat exchanger and the 4-way switching valve. are doing.

(Function) When performing cooling with the vehicle air conditioning system of the present invention, the four-way switching valve is switched to the cooling position and the compressor is operated. The refrigerant discharged from the compressor flows through the four-way switching valve to the outdoor heat exchanger, the expansion valve, and the indoor heat exchanger in this order, and as a result, heat absorption occurs in the indoor heat exchanger and is transferred to the passenger compartment. is cooled. After flowing through the outdoor heat exchanger, the refrigerant returns to the compressor.

On the other hand, when performing heating, the four-way switching valve is switched to the heating position and the compressor is operated. The refrigerant discharged from the compressor flows through the four-way switching valve to the indoor heat exchanger, whereby a heat dissipation effect occurs in the indoor heat exchanger and the interior of the vehicle is heated.
After flowing through the indoor heat exchanger, the refrigerant passes through the expansion valve and the outdoor heat exchanger, and returns to the compressor.

In addition, when heating the passenger compartment immediately after engine operation starts, such as during the winter when the outside temperature is low, the four-way switching valve is switched to the heating position, and the opening degree of the expansion valve is reduced to open the switching valve to compress the air. Activate the machine. The refrigerant discharged from the compressor flows through the four-way switching valve to the indoor heat exchanger, whereby a heat dissipation effect occurs in the indoor heat exchanger and the interior of the vehicle is heated. A part of the refrigerant that has passed through the indoor heat exchanger passes through the switching valve to the exhaust gas heat exchanger, is heated by the exhaust heat of the exhaust gas, and returns to the compressor. Further, the remaining refrigerant flows through the expansion valve and the outdoor heat exchanger, and returns to the compressor.

(Example) Figure 1 shows an example of the present invention.
is a car engine, 11 is an engine exhaust pipe,
12 is a pump that pumps up the cooling water of the engine 10;
13 is a compressor connected to the engine 10 by a belt mechanism 14, 15 is a four-way switching valve, 16 is an accumulator, 17 is an indoor heat exchanger, 18 is an outdoor heat exchanger, and 19 is a heater for indoor heating. Heater core, 20 is an exhaust gas heat exchanger, 21 is an expansion valve, 22
is a switching valve.

First refrigerant flow port 15a of four-way switching valve 15
A second refrigerant flow port 15 is provided on the discharge side of the compressor 13.
b is on the suction side of the accumulator 16, the third refrigerant flow port 15c is on one end side of the indoor heat exchanger 17, and the fourth refrigerant flow port 15d is on the outdoor heat exchanger 1.
6, respectively. Further, the discharge side of the accumulator 16 is connected to the suction side of the compressor 13, and the other end of the indoor heat exchanger 17 is connected to the outdoor side heat exchanger via an expansion valve 21 whose opening degree is controlled by a controller 21a. They are respectively connected to the other ends of the vessel 18.

In this embodiment, the compressor 13, four-way switching valve 15, accumulator 16, indoor heat exchanger 17, outdoor heat exchanger 18, and expansion valve 21 constitute an air conditioning heat pump.

As shown in FIG. 2, the above exhaust gas heat exchanger 20 includes a horizontally long outer cylinder 20a having ring-shaped side plates on both sides, and an inner cylinder 20b arranged inside the outer cylinder 20a at a predetermined distance. and an exhaust flow pipe 20c located inside the inner cylinder 20b with a predetermined distance therebetween. Further, a refrigerant inflow pipe 20d and a refrigerant outflow pipe 20e are provided on a part of the outer peripheral surface of the outer cylinder 20a, and the refrigerant inflow pipe 20d is connected to a normally closed switching valve 22.
The refrigerant outflow pipe 20e is connected to the connection midpoint between the indoor heat exchanger 17 and the expansion valve 21 via the It is connected to the connection midpoint between the fourth refrigerant flow port 15d of the switching valve 15 and the outdoor heat exchanger 18. Further, each end face of the inner cylinder 20b is sealed and attached to the inner circumferential surface of the side plate of the outer cylinder 20a, and the inside thereof is filled with oil having good heat resistance and thermal conductivity, and low specific gravity and coefficient of thermal expansion. There is. Furthermore, a plurality of ring-shaped heat exchange fins 20f are provided near the center in the longitudinal direction of the exhaust flow pipe 20c, and both ends of the ring-shaped heat exchange fins 20f are connected between the exhaust pipes 11 via flare nuts 20g passing through the end face of the inner cylinder 20b. ing.

The discharge side and suction side of the pump 12 are connected to the heater core 19, respectively, so that the cooling water of the engine 10 can be circulated to the heater core 9.

In addition, 24 is an indoor heat exchanger 1 which transfers the air inside and outside the vehicle.
7 and the heater core 19, and blows heat exchange air into the vehicle interior.

When cooling the vehicle interior with the vehicle air conditioning system described above, the four-way switching valve 15 is switched to the cooling position, the first refrigerant flow port 15a and the fourth refrigerant flow port 15d are connected, and the fourth refrigerant flow port 15a is connected to the fourth refrigerant flow port 15d. 2 refrigerant flow port 1
5b and the third refrigerant flow port 15c are connected, the compressor 13 is operated via the engine 10.

By the operation of this compressor 13, the compressor 13
As shown by the solid arrow, the refrigerant discharged from 4
an outdoor heat exchanger 18 via a directional switching valve 15;
The air flows through the expansion valve 21 and the indoor heat exchanger 17 in this order, and as a result, heat absorption occurs in the indoor heat exchanger 17, thereby cooling the interior of the vehicle. Indoor heat exchanger 1
7, the refrigerant passes through the accumulator 16.
It returns to the compressor 13 via.

On the other hand, when heating the vehicle interior with the same air conditioning system, the four-way switching valve 15 is switched to the heating position, the first refrigerant flow port 15a and the third refrigerant flow port 15c are connected, and the second Refrigerant flow port 15a
The compressor 13 is operated via the engine 10 with the fourth refrigerant flow port 15d connected.

By the operation of this compressor 13, the compressor 13
The refrigerant discharged from the refrigerant flows through the four-way switching valve 15 to the indoor heat exchanger 17 as shown by the dashed-dotted arrow, and thereby the indoor heat exchanger 17
A heat dissipation effect occurs and the interior of the vehicle is heated. After flowing through the indoor heat exchanger 17, the refrigerant passes through the expansion valve 21.
and flows through the outdoor heat exchanger 18 and returns to the compressor 13 via the accumulator 16.

In addition, when heating the passenger compartment immediately after starting engine operation in winter when the outside temperature is low, the four-way switching valve 15 is switched to the heating position in the same way as above, and the opening degree of the expansion valve 21 is reduced. The switching valve 22 is opened to operate the compressor. Compressor 1
The refrigerant discharged from the refrigerant 3 flows through the four-way switching valve 15 to the indoor heat exchanger 17, whereby a heat radiation effect occurs in the indoor heat exchanger 17 and the interior of the vehicle is heated. A part of the refrigerant that has passed through the indoor heat exchanger 17 passes through the switching valve 22 to the exhaust gas heat exchanger 20 as shown by the double-dashed arrow, and is heated by the exhaust heat of the exhaust gas. After that, it returns to the compressor 13 via the accumulator 16. Further, the remaining refrigerant flows through the expansion valve 21 and the outdoor heat exchanger 18, and passes through the accumulator 16 to the compressor 13.
Return to

That is, in the vehicle air conditioning system described above, by reducing the opening degree of the expansion valve 21 and opening the switching valve 22, a part of the refrigerant that has passed through the indoor heat exchanger 17 is transferred to the exhaust gas heat exchanger. 20 and can be heated using the exhaust heat of the exhaust gas, so the outdoor heat exchanger 18 cannot be expected to have a sufficient heat absorption effect (refrigerant evaporation effect) in winter when the outside temperature is low. In addition, even if heating cannot be expected by circulating the cooling water immediately after the engine starts operating, the refrigerant after heat radiation absorbs enough heat to operate the heat pump effectively and quickly provide heating. It is.

Furthermore, in the vehicle air conditioning system described above, the heater core 19 is provided separately from the heat pump, so when the temperature of the engine cooling water rises to a point where it can be used for heating due to the operation of the engine 10, the heat pump Stop operation and pump 12
is operated to transfer the cooling water of the engine 10 to the heater core 1.
It is also possible to heat the interior of the vehicle by circulating the air at 9.

(Effects of the invention) As explained above, according to the invention, the following effects can be obtained.

By a simple switching operation of the four-way switching valve, the indoor heat exchanger selectively causes heat absorption and heat radiation, and the interior of the vehicle can be appropriately cooled and heated.

Even when heating the passenger compartment immediately after engine operation starts, such as in winter when the outside temperature is low, by opening the switching valve with a small opening of the expansion valve, the refrigerant after passing through the indoor heat exchanger can be heated. A portion of the refrigerant is passed through the exhaust gas heat exchanger, and the refrigerant can be heated using the exhaust heat of the exhaust gas, allowing the refrigerant to absorb sufficient heat after heat dissipation to effectively operate the heat pump. heating can be done quickly.

Since the configuration is simple, the system itself can be constructed at low cost.In addition, the same air conditioning system can be configured by connecting the switching valve and exhaust gas heat exchanger to an existing heat pump, so retrofitting work etc. It is advantageous and highly versatile.

Since the exhaust gas does not come into direct contact with the indoor heat exchanger and the exhaust gas heat exchanger, corrosion and the like will not occur on them, and cooling water using exhaust heat can be used satisfactorily over a long period of time.

[Brief explanation of the drawing]

Figures 1 and 2 show an embodiment of the present invention. Figure 1 is a piping diagram of a heat pump vehicle air conditioning system, Figure 2 is a partially omitted cross-sectional perspective view of an exhaust gas heat exchanger, and Figure 2 is a partially omitted cross-sectional perspective view of an exhaust gas heat exchanger. FIG. 3 is a configuration diagram of a conventional vehicle air conditioning system. In the diagram, 10...engine, 11...exhaust pipe, 1
3...Compressor, 15...4-way switching valve, 17...
...Indoor heat exchanger, 18...Outdoor heat exchanger, 2
0... Exhaust gas heat exchanger, 21... Expansion valve, 22...
...Switching valve.

Claims (1)

[Claims for Utility Model Registration] Refrigerant discharged from a compressor driven by an engine is passed through a four-way switching valve to an indoor heat exchanger,
A heating cycle in which the refrigerant is passed through the expansion valve and the outdoor heat exchanger in this order, and a cooling cycle in which the refrigerant discharged from the compressor is passed in this order through the outdoor heat exchanger, the expansion valve and the indoor heat exchanger via a four-way switching valve. In a vehicle air conditioning system equipped with a heat pump that can be operated in a switching cycle, an expansion valve whose opening can be controlled electrically is used as an expansion valve, and exhaust gas is collected outside the engine exhaust pipe to recover the heat of the exhaust gas. A heat exchanger is attached, and the refrigerant suction side of the exhaust gas heat exchanger is connected to the connection midpoint between the indoor heat exchanger and the expansion valve via a switching valve, and the refrigerant discharge side of the exhaust gas heat exchanger is connected to the connection point between the indoor heat exchanger and the expansion valve. A heat pump air conditioning system for a vehicle, characterized in that the air conditioning system is connected to a midpoint of connection between an outside heat exchanger and a four-way switching valve.