JPH1142931A - Air conditioning for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a quick cooling or heating by providing an auxiliary heat exchanger for heat-exchanging an engine cooling water with a heat exchange medium flowing in a heat exchange medium passage, and effectively performing the heating of the heat exchange medium in heating and the cooling of the heat exchange medium in cooling. SOLUTION: In heating by a cooling and heating cycle A, a heat exchange medium is raised in temperature and pressure by a compressor 13 and allowed to flow into an inside heat exchanger 15 to heat the passing air. Not only evaporation is performed to absorb the heat from the outside air by an outside heat exchanger 14, but also the heat is absorbed from engine cooling water by an auxiliary exchanger 12. In cooling, on the other hand, the heat exchange medium is passed in the auxiliary heat exchanger 12 in high-temperature, high- pressure gaseous state. Since the engine cooling water is passed through the auxiliary heat exchanger 12 by a passage switching device 23, the heat can be released from the heat exchange medium to the engine cooling water. Thus, the blowing air temperature can be quickly lowered or raised in the initial stage of cooling or heating start.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air conditioner, and more particularly to a vehicle air conditioner having an auxiliary heating function.

[0002]

2. Description of the Related Art Conventionally, in a vehicle air conditioner, a cooling cycle A comprising a compressor 1, a condenser 2, an accumulator 3, a throttle valve 4 and an evaporator 5 and an engine cooling cycle B are provided as shown in FIG. And a heater core 6.

In the engine cooling cycle B, in addition to the heater core 6, a water pump 8, a radiator 9, a bypass passage 10a, and a water passage switching device 10b provided in the engine 7 are provided. The heater core 6, the radiator 9, and the bypass passage 10a are connected in parallel. The water channel switching device (thermostat) 10b allows water to flow through the bypass passage 10a until the engine cooling water reaches a predetermined temperature, and to flow through the radiator 9 when the engine cooling water reaches the predetermined temperature.

[0004]

However, for example, in a recent high-efficiency diesel engine or the like, the temperature of the engine 7 does not rise, and therefore the temperature of the engine cooling water cannot be so much expected. Therefore, if the temperature of the engine cooling water is used by the heater core 6 as in the conventional vehicle air conditioner, it is difficult to quickly heat the inside of the vehicle.

In the conventional vehicle air conditioner, when cooling the interior of the vehicle, the refrigerant is circulated and radiated to the outside air by the condenser 2, and is evaporated by the evaporator 5 to absorb heat from the air blown into the vehicle. In this case, if the outside air temperature is high, heat radiation to the outside of the vehicle by the condenser 2 does not go smoothly, and rapid cooling is difficult.

Accordingly, an object of the present invention is to provide an air conditioner for a vehicle that enables rapid cooling and heating.

[0007]

According to the present invention, there is provided a cooling / heating cycle having a compressor, an outside heat exchanger, and an inside heat exchanger in a heat exchange medium flow path as means for solving the above problems. In a vehicle air conditioner comprising a radiator water channel having a radiator that can be passed to only one of them by a water channel switching unit and a heater core provided in a heater core water channel connected in parallel to a cooling water bypass water channel, In the medium channel and the cooling water bypass channel,
An auxiliary heat exchanger for exchanging heat between the heat exchange medium flowing through the heat exchange medium flow path and the engine cooling water flowing through the cooling water bypass water path is provided.

[0008] According to the above configuration, when heating the inside of the vehicle, the heat exchange medium can absorb heat from the engine cooling water in the auxiliary heat exchanger to improve the heating capacity. Further, when cooling the interior of the vehicle, heat can be radiated from the heat exchange medium to the engine cooling water by the auxiliary heat exchanger, so that the cooling capacity can be improved.

[0009] A flow rate adjusting means may be provided between the water channel switching means and the auxiliary heat exchanger.

In this case, the flow rate adjusting means may have a configuration in which a fixed throttle valve and a flow path opening / closing valve are connected in parallel.

The flow rate adjusting means may be one which increases or decreases the amount of flowing water according to the temperature of the heat exchange medium when the temperature of the heat exchange medium is lower than the temperature set by the water path switching means.

With this configuration, the flow rate of the engine cooling water in the auxiliary heat exchanger can be changed according to the difference in the temperature. Therefore, when heating the interior of the vehicle, if the outside air temperature is low and the temperature of the engine coolant does not rise so much, the flow rate of the engine coolant in the auxiliary heat exchanger, that is, the heat capacity, increases. This makes it possible to sufficiently absorb heat to the heat exchange medium. On the other hand, when cooling the inside of the vehicle, if the outside air temperature is high and the temperature of the engine coolant is rising, the flow rate of the engine coolant in the auxiliary heat exchanger is suppressed. Thereby, the heat radiation from the heat exchange medium can be suppressed, and the temperature rise of the engine cooling water can be suppressed.

[0013] The vehicle-side heat exchanger of the heat exchange medium flow path,
It is preferable to connect a heat exchange medium bypass passage that allows the heat exchange medium to flow only during heating.

According to this structure, when the outside air temperature is low, heat can be absorbed from the engine cooling water by the auxiliary heat exchanger without using the vehicle-side heat exchanger having poor heat absorption efficiency. Heating inside the car becomes possible.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) A vehicle air conditioner shown in FIG. 1 generally includes a heating / cooling cycle A, a heater core 11 disposed in the middle of an engine cooling cycle B, and a cooling / heating cycle A and an engine cooling cycle B. And an auxiliary heat exchanger 12 provided on both sides.

In the cooling / heating cycle A, a compressor 13, an outside heat exchanger 14 and an inside heat exchanger 15 are provided in the middle of a heat exchange medium flow path a, and the heat exchange medium is supplied in two directions via a four-way valve 16. It is one that can be circulated. The auxiliary heat exchanger 12 is connected between the vehicle exterior heat exchanger 14 and the four-way valve 16. The auxiliary heat exchanger 12 may be of any type such as a double tube type, a shell and coil type, a plate type, etc. In short, a heat exchange medium circulating in the cooling / heating cycle A and an engine cooling cycle described below Any material may be used as long as heat is exchanged with the engine cooling water circulating B. Reference numeral 17 denotes an electric expansion valve which is a pressure reducing means.
8 is an accumulator for gas-liquid separation.

In the engine cooling cycle B, a water pump 20 provided in the engine 19, and a radiator 21 and a heater core 11 connected in parallel to the water pump 20 are provided in the engine cooling water passage b. In the engine 19, four cooling water pipes 22 are connected in parallel. The radiator 21 includes a waterway switching device 23
The cooling water bypass water passage 24 and the auxiliary heat exchanger 12 are connected in parallel via the. The water channel switching device 23 determines that the temperature of the engine cooling water is the first set temperature (8 in the present embodiment).
Until the temperature exceeds 0 ° C.), the supply of the engine cooling water to the radiator 21 is shut off, and after exceeding the temperature, the operation is switched to be allowed.

The heat exchanger 15 and the heater core 1 inside the vehicle
As shown in FIG. 2, 1 is disposed in a blower unit 25 provided at a front part in the vehicle. Inside the blower unit 25, a blower 26 and the heat exchanger 1 inside the vehicle are sequentially arranged from the upstream side.
5. An air mix damper 27 is provided, and the heater core 11 is provided in one of the flow paths divided by the air mix damper 27.

Next, the operation of the vehicle air conditioner will be described.

First, the operation in the engine cooling cycle B will be described.

When the engine 19 is started, the engine 19
The internal water pump 20 is driven, and engine cooling water flows through the heater core 11.

At this time, the temperature of the engine cooling water is 80 ° C.
If not, the water channel switching device 23 is switched as shown in FIG. 1, and the flow of water to the radiator 21 is blocked. The engine cooling water flows into the cooling water bypass passage 24 and the auxiliary heat exchanger 12 via the water passage switching device 23.
Thus, when the engine cooling water is not so warmed immediately after the start of the engine or the like, the cooling water is not cooled by the radiator 21.

When the temperature of the engine cooling water exceeds 80 ° C., the water channel switching device 23 is switched, and the flow of water to the cooling water bypass passage 26 and the auxiliary heat exchanger 12 is blocked. Thereby, the engine cooling water flows through the radiator 21 and is radiated to the outside air.

Next, the operation of the cooling / heating cycle A will be described.

In the case of heating, that is, when a heat pump switch (not shown) is operated, the four-way valve 16 is switched as shown by a solid line, and a so-called heat pump cycle is formed. The heat exchange medium discharged from the compressor 13 is supplied to the vehicle interior heat exchanger 15, the electric expansion valve 17, the vehicle exterior heat exchanger 14, the auxiliary heat exchanger 12, and the accumulator 1.
8 and return to the compressor 13 for circulation. The heat exchange medium is made high temperature and high pressure by the compressor 13 and flows into the vehicle interior heat exchanger 15 to heat the air passing through the blower unit 25. In addition, the auxiliary heat exchanger 12 not only vaporizes and absorbs heat from the outside air, but also absorbs heat from the engine cooling water. Therefore, the heat exchange medium returns to the compressor 13 with the heat capacity increased. For this reason, in the present embodiment, the discharge pressure of the compressor 13 can be set to about 2.6 MPa and the condensing temperature can be set to about 80 ° C., so that a very high heating capacity can be exhibited (from the air). With a conventional heat pump that absorbs heat, the discharge pressure is 1.1 MPa and the condensation temperature is about 4 even when the outside air temperature is -8 ° C.
5 ° C., unsuitable for heating).

FIG. 3 is a graph showing a comparison result of the blowing air temperature during heating between the first embodiment and the conventional example. As is clear from this graph, according to the vehicle air conditioner according to the first embodiment, it is possible to quickly increase the blast temperature in the initial stage of heating start.

In addition, by using the heat pump cycle capable of absorbing heat from the engine cooling water as described above, the blowing temperature can be raised by the heat exchanger 15 having a larger capacity than the heater core 11. For this reason,
It is possible to supply air at a desired temperature into the vehicle while securing a desired air flow rate. Moreover, if the temperature of the engine cooling water becomes high (80 ° C. or more in the present embodiment), the auxiliary heat exchanger 12
Since the flow of water to the heat exchange medium is shut off, the heat exchange medium in the heat pump cycle does not become abnormally high in pressure due to the heat exchange medium being heated more than necessary.

In the case of cooling, that is, when an air conditioner (A / C) switch (not shown) is operated, the four-way valve 16
Switches as shown by the dotted line, and a so-called refrigeration cycle is formed. The heat exchange medium discharged from the compressor 13 circulates back to the compressor 13 from the auxiliary heat exchanger 12, the outside heat exchanger 14, the electric expansion valve 17, the inside heat exchanger 15, and the accumulator 18.
The heat exchange medium is an auxiliary heat exchanger 1 in a high temperature and high pressure gas state.
Pass 2 At this time, the temperature of the engine cooling water is 80
If the temperature is lower than 0 ° C., the engine cooling water passes through the auxiliary heat exchanger 12 by the water channel switching device 23 as described above.
Heat can be released from the heat exchange medium to the engine cooling water. In addition, the heat exchange medium is also radiated to the outside air in the vehicle-side heat exchanger 14. Therefore, the pressure is reduced by passing through the electric expansion valve 17, the amount of the heat exchange medium vaporized in the in-vehicle heat exchanger 15 is increased, and the air passing through the blower unit 25 can be effectively cooled. .

FIG. 4 is a graph showing a comparison result of the air blowing temperature at the time of cooling between the first embodiment and the conventional example. As is clear from this graph, according to the vehicle air conditioner according to the first embodiment, it is possible to rapidly lower the blast temperature in the initial stage of cooling start.

Second Embodiment A vehicle air conditioner shown in FIG. 5 is different from that shown in FIG. 1 in that a flow control device 28 is provided between a water channel switching device 23 and an auxiliary heat exchanger 12. different. In this flow control device 28, a flow passage opening / closing valve 29 and a fixed throttle valve 30 are connected in parallel. Flow path on-off valve 2
Numeral 9 is for opening the flow passage at a temperature lower than a second set temperature lower than the first set temperature set by the water channel switching device 23 and closing the flow passage at a temperature equal to or higher than the second set temperature. The second set temperature is set to 40 ° C. in the present embodiment.

In the vehicle air conditioner provided with such a flow control device 28, when the temperature of the engine cooling water is lower than the second set temperature, the flow path opening / closing valve 29 is opened and the auxiliary heat exchanger 12 The flow rate of the engine cooling water is large. on the other hand,
If the temperature of the engine cooling water is equal to or higher than the second set temperature and lower than the first set temperature, the flow path opening / closing valve 29 is closed, and the flow rate of the engine cooling water in the auxiliary heat exchanger 12 is suppressed.

Therefore, when heating the inside of the vehicle, if the outside air temperature is low and the temperature of the engine cooling water is low, the heat capacity of the auxiliary heat exchanger 12 is increased by increasing the flow rate of the engine cooling water. This makes it possible to sufficiently absorb the heat in the heat exchange medium and improve the heating capacity. Further, when cooling the inside of the vehicle, if the outside air temperature is high and the temperature of the engine cooling water is high, the flow rate of the engine cooling water in the auxiliary heat exchanger 12 is reduced, so that the heat exchange medium discharges the engine cooling water. The amount of heat is suppressed. Accordingly, when the outside air temperature is high and the radiator 21 cannot sufficiently release heat, it is possible to prevent the engine cooling water from being heated more than necessary.

Third Embodiment A vehicle air conditioner shown in FIG. 6 is different from the air conditioner shown in FIG. 1 in that a heat exchange medium bypass passage 31 is connected in parallel to an outside heat exchanger 14 of a heat exchange medium cycle. The points are different. An on-off valve 32 is provided between the vehicle exterior heat exchanger 14 and the auxiliary heat exchanger 12,
A first check valve 33 is provided between the first heat exchanger and the inside heat exchanger. In the heat exchange medium bypass passage 31, a second check valve 34 and a throttle valve 35 are provided.

Such a heat exchange medium bypass passage 31
In the vehicle air conditioner provided with the heat exchanger, when the inside of the vehicle is heated, the heat exchange medium discharged from the compressor 13 flows through the heat exchange medium bypass passage 31 from the inside heat exchanger 15, but the first check valve 33 does not flow into the heat exchanger 14 on the outside of the vehicle. Therefore, since the heat exchange medium does not pass through the outside heat exchanger 14 having a low outside air temperature and poor heat absorption capacity, the load on the compressor 13 can be reduced. Further, since the heat exchange medium can absorb heat from the engine cooling water in the auxiliary heat exchanger 12, it is sufficient to heat the inside of the vehicle. In the interior heating, the on-off valve 32 is closed to prevent the heat exchange medium from flowing into the exterior heat exchanger 14 and to prevent the heat exchange medium from staying in the exterior heat exchanger 14. . When the outside air temperature is high and the inside of the vehicle is cooled, the heat exchange medium discharged from the compressor 13 flows from the auxiliary heat exchanger 12 into the vehicle outside heat exchanger 14, and is exchanged by the second check valve 34. Bypass passage 3
Does not flow into 1.

As shown in FIG. 7, the vehicle air conditioner has both a flow rate adjusting device 28 of the second embodiment and a heat exchange medium bypass passage 31 of the third embodiment. Is also good.

[0037]

As is apparent from the above description, according to the vehicle air conditioner of the present invention, the auxiliary heat exchange for exchanging heat between the engine cooling water and the heat exchange medium flowing in the heat exchange medium flow path. Since the heat exchanger is provided, the heating of the heat exchange medium during heating and the cooling of the heat exchange medium during cooling can be effectively performed, and the effect of the rapid effect of cooling and heating is exhibited.

Further, since the flow rate adjusting means is arranged between the water channel switching means and the auxiliary heat exchanger, the heat capacity of the engine cooling water flowing through the auxiliary heat exchanger is stabilized, and Heat exchange can be sufficiently performed to realize a stable cooling and heating environment.

Also, since a bypass passage for the heat exchange medium which permits the flow of the heat exchange medium only during heating is connected in parallel to the vehicle-side heat exchanger, the vehicle-side heat exchanger having poor heat absorption efficiency can be bypassed to provide a good heat exchange medium. A flow of the heat exchange medium can be formed, and efficient heat exchange can be performed using the auxiliary heat exchanger.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a vehicle air conditioner according to a first embodiment.

FIG. 2 is a cross-sectional view of a blower unit in which the vehicle interior heat exchanger and the heater core of FIG. 1 are disposed.

FIG. 3 is a graph showing a comparison of a ventilation temperature during heating between the vehicle air conditioner of FIG. 1 and a conventional example.

4 is a graph comparing the air-conditioning temperature during cooling between the vehicle air conditioner of FIG. 1 and the conventional air conditioner.

FIG. 5 is a schematic diagram of a vehicle air conditioner according to a second embodiment.

FIG. 6 is a schematic diagram of a vehicle air conditioner according to a third embodiment.

FIG. 7 is a schematic diagram of a vehicle air conditioner according to another embodiment.

FIG. 8 is a schematic diagram of a vehicle air conditioner according to a conventional example.

[Explanation of symbols]

 11 Heater Core 12 Auxiliary Heat Exchanger 13 Compressor 14 Outside Heat Exchanger 15 Inside Heat Exchanger 19 Engine 20 Water Pump 21 Radiator 24 Cooling Water Bypass Channel

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yasuyuki Inoue 5658 Yoshikawa, Hachihonmatsu-cho, Higashihiroshima-shi, Hiroshima Japan Climate Systems Co., Ltd.

Claims (5)

[Claims] 1. A cooling / heating cycle having a compressor, an outside heat exchanger, and an inside heat exchanger in a heat exchange medium flow path, and a radiator that can be passed through only one of them by a water path switching means. In a vehicle air conditioner comprising a heater core provided in a heater core water passage connected in parallel to a radiator water passage and a cooling water bypass water passage, a heat exchange medium flow passage is provided between the heat exchange medium flow passage and the cooling water bypass water passage. An air conditioner for a vehicle, comprising an auxiliary heat exchanger for exchanging heat between a flowing heat exchange medium and engine cooling water flowing in a cooling water bypass channel. 2. A flow rate adjusting means is provided between the water channel switching means and the auxiliary heat exchanger.
A vehicle air conditioner according to claim 1. 3. A vehicle air conditioner according to claim 2, wherein said flow rate adjusting means has a configuration in which a fixed throttle valve and a flow path opening / closing valve are connected in parallel. 4. The method according to claim 1, wherein said flow rate adjusting means increases or decreases the amount of flowing water according to the temperature of the heat exchange medium when the temperature of said heat exchange medium is lower than a set temperature of said water path switching means. The vehicle air conditioner according to claim 1. 5. A heat-exchange-medium bypass passage that allows the heat-exchange medium to flow only during heating is connected in parallel to the vehicle-side heat exchanger in the heat-exchange medium flow path. The vehicle air conditioner according to any one of the above.