JP3284573B2 - Vehicle air conditioner - Google Patents

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 for heating a vehicle interior by utilizing heat radiation from a cooling water of a vehicle driving engine and a heat pump.

[0002]

2. Description of the Related Art Conventionally, for example, a heating system mounted on a large bus has a cooling water of an engine for driving a vehicle which is guided into a heater unit by using a pipe and is heated by a preheater. To the hot water heater to exchange heat with the air inside the vehicle.

[0003]

However, in recent years,
There is a tendency that the efficiency of the vehicle drive engine is improved and the amount of heat radiation (the amount of heat absorbed by the cooling water) of the vehicle drive engine is reduced, and accordingly, it is necessary to increase the capacity of the preheater.

[0004] However, if the capacity of the preheater is increased, problems such as deterioration of fuel economy occur. In addition, when the heating is started at a low temperature, since the temperature of the cooling water is low immediately after the engine for driving the vehicle is also started, even if the cooling water is supplied to the hot water heater, it hardly contributes to the rise in the temperature of the air inside the vehicle, Conversely, the temperature rise of the vehicle driving engine (temperature rise of the cooling water) is unnecessarily prevented, so that the rise of heating at low temperature becomes extremely poor and the fuel efficiency of the vehicle driving engine also deteriorates. There is a disadvantage that.

[0005] The present invention has been made in view of such circumstances, and the object thereof is to eliminate the need for a preheater whose capacity is increasing, and to speed up the rise of heating at low temperatures, It is an object of the present invention to provide a vehicle air conditioner capable of rapidly raising the temperature rise (temperature rise of cooling water) of the vehicle drive engine and improving fuel efficiency.

[0006]

A vehicle air conditioner according to the present invention comprises a hot water heater provided in a cooling water circulation circuit for cooling an engine for driving a vehicle, and a compressor which circulates the refrigerant so that the refrigerant in the refrigerant circulation circuit is provided. A heat pump that radiates heat from the heat exchanger inside the vehicle and heats the interior of the vehicle; an air conditioning engine that drives the compressor; and a cooling water circulation circuit that cools the air conditioning engine.
An exhaust heat recovery heat exchanger for recovering the exhaust heat of the air conditioning engine absorbed by water to the refrigerant, and a cooling water heat recovery heat exchange for recovering the cooling water of the vehicle drive engine to the refrigerant A valve for selectively switching a cooling water circulation path of the vehicle driving engine between the hot water heater side and the cooling water heat recovery heat exchanger side; An exhaust heat temperature increasing means for increasing the heat temperature, and a cooling water heat recovery heat exchange from the hot water heater side by the valve through a circulation path of the cooling water of the vehicle driving engine when the heating is started at a low temperature. Control so as to temporarily increase the load on the air-conditioning engine by operating the exhaust heat temperature increasing means while switching to the state of switching to the air conditioner side.
Air-conditioning control means for raising the temperature of the cooling water of the air-conditioning engine .

[0007]

According to the present invention, the interior of the vehicle is heated by utilizing the heat radiation of the cooling water of the engine for driving the vehicle and the heat pump. However, when the heating is started at a low temperature, the cooling of the engine for driving the vehicle is performed. The water circulation path is switched from the hot water heater having a large amount of heat radiation to the cooling water heat recovery heat exchanger. As a result, the heat radiation of the cooling water immediately after the start of the vehicle driving engine is reduced, and the temperature rise of the cooling water (the temperature rise of the vehicle driving engine) is accelerated. By collecting it in the refrigerant by
The heat radiation of the cooling water is effectively used for heating by the heat pump.

Further, at the start of heating at a low temperature, the exhaust heat temperature of the air conditioning engine is increased by temporarily increasing the load of the air conditioning engine that drives the compressor of the heat pump by the exhaust heat temperature increasing means . Air conditioning engine
The waste heat absorbed by the cooling water is recovered by the refrigerant by a waste heat recovery heat exchanger. As a result, the above-described vehicle drive
In combination with the recovery of the heat radiation of the cooling water of the engine, the heat energy transported by the refrigerant is greatly increased, the heating capacity of the heat pump is remarkably increased, and the heating start-up at low temperatures is accelerated.

In this case, the heat pump can function as a refrigeration cycle for cooling the interior of the vehicle during cooling if the direction of circulation of the refrigerant in the refrigerant circuit is reversed.
A single heat pump can be used for both cooling and heating, and does not cause an increase in the size of the device as compared with a conventional structure having a refrigeration cycle dedicated to cooling and a large-capacity preheater.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. The vehicle air conditioner of this embodiment is mounted on, for example, a large bus, and its cycle structure will be described first.

As shown in FIG. 1, a vehicle driving engine 1
A radiator 3, a water pump 4, a defroster 5 for defrosting window glass,
Two electromagnetic valves 6 and 7, a hot water heater 8 and a heat exchanger 9 for cooling water heat recovery described later are provided. In this case, the solenoid valve 7 and the series circuit 2b of the cooling water heat recovery heat exchanger 9 are connected in parallel with the series circuit 2a of the solenoid valve 6 and the hot water heater 8, and the cooling is performed by switching the solenoid valves 6 and 7. The water circulation path is selectively switched between the hot water heater 8 side and the cooling water heat recovery heat exchanger 9 side. Further, the performance of the defroster 5 is improved by sending the cooling water heated by the vehicle drive engine 1 to the hot water heater 8 through the defroster 5.

On the other hand, the heat pump 10 includes a compressor 12, a four-way valve 13, a vehicle interior heat exchanger 14, an electronic expansion valve 15, a vehicle exterior heat exchanger 16, and a heat exchanger for cooling water heat recovery in a refrigerant circuit 11. 9. Exhaust heat recovery heat exchanger 17, check valve 18, accumulators 19 and 4.
Two solenoid valves 20 to 23 are provided. In this case, the solenoid valve 20, the coolant heat recovery heat exchanger 9, the exhaust heat recovery heat exchanger 17, and the solenoid valve 22 are connected to the series circuit 11a of the solenoid valve 21, the vehicle exterior heat exchanger 16 and the solenoid valve 23. Are connected in parallel, and the refrigerant circulation path is selectively switched between the vehicle-side heat exchanger 16 side and the cooling water heat recovery heat exchanger 9 side by switching the solenoid valves 20 to 23. Has become. Further, the check valve 18 is connected to the heat exchanger 17 for exhaust heat recovery.
The refrigerant passage 11 b on the side is connected to the discharge pipe 1 of the compressor 12.
It is provided in a bypass passage 11c for bypassing to the 2a side.

The compressor 1 of the heat pump 10
2 is driven by an air conditioning engine 24. A cooling water circulation circuit 25 for cooling the air conditioning engine 24
An exhaust heat exchanger 26 for exchanging heat with the exhaust air from the air conditioning engine 24, the exhaust heat recovery heat exchanger 17, a radiator 27, and two solenoid valves 28 and 29 are provided therein. In this case, a series circuit 25b of the solenoid valve 29 and the radiator 27 is connected in parallel to a series circuit 25a of the solenoid valve 28 and the heat exchanger 17 for exhaust heat recovery. The circulation path is selectively switched between the exhaust heat recovery heat exchanger 17 side and the radiator 27 side.

Further, the exhaust pipe 30 of the air conditioning engine 24 is provided with an exhaust throttle device 31 as an exhaust heat temperature increasing means.
1 is operated to narrow the exhaust passage, thereby increasing the exhaust pressure (load of the air conditioning engine 24) to increase the exhaust heat temperature.

The cooling water heat recovery heat exchanger 9 and the waste heat recovery heat exchanger 17 are so-called shell-and-tube heat exchangers, and the cooling water flows on the shell side (primary side). The refrigerant flows to the tube side (secondary side). On the other hand, the vehicle interior heat exchanger 14 and the vehicle exterior heat exchanger 16 exchange heat with air, and are provided with fans 40 and 41 to promote the heat exchange.

On the other hand, an electric circuit related to the air-conditioning control is shown in FIG. 2, and the air-conditioning control circuit 32 as the air-conditioning control means is constituted by, for example, a microcomputer. The air conditioning control circuit 32 includes an outside temperature sensor 33 for detecting the outside temperature To, and an inside temperature sensor 3 for detecting the inside temperature Ti.
4. A water temperature sensor 35 for detecting the temperature Tw of the cooling water of the engine 1 for driving the vehicle, an air temperature sensor 36 for detecting the temperature Tf of the air blown from the heat exchanger 14 on the inside of the vehicle, and manually setting the air-conditioning temperature. Temperature setting circuit 3 set by operation
Based on the information from 7, the air-conditioning operation is controlled according to the control programs shown in FIGS. In this case, the control of start / stop / acceleration / deceleration of the air conditioning engine 24 is performed via the engine control circuit 38. Also,
The user can start / stop the air conditioning operation by using the air conditioner switch 3
9 is turned on and off.

Hereinafter, the flow of the control of the air-conditioning operation by the air-conditioning control circuit 32 will be described in detail according to the control program shown in FIGS. When the user turns on the air conditioner switch 39, the air conditioning operation control program shown in FIGS. 3 and 4 starts, and first, signals output from the outside temperature sensor 33, the inside temperature sensor 34, and the temperature setting circuit 37 are output. It reads, outside temperature To, inside temperature Ti,
The set temperature Ts is detected (step S1). Then, the vehicle interior temperature Ti is compared with the set temperature Ts (step S2),
If the in-vehicle air temperature Ti is equal to or higher than the set temperature Ts (Ti ≧ Ts), the determination in step S2 becomes “NO”, and the process proceeds to step S3 to operate in the cooling mode.

In the cooling mode, the four-way valve 13 is switched to the position shown by the broken line in FIG.
9 is opened and the air-conditioning engine 24 is started to operate the compressor 12 of the heat pump 10 in a state where the solenoid valves 6, 7, 20, 22, and 28 are closed, so that the refrigerant discharged from the compressor 12 is discharged. , Outside heat exchanger 1
6 → electronic expansion valve 15 → inside heat exchanger 14 → accumulator 19 → compressor 12 As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 12 is sent to the heat exchanger 16 on the outside to radiate and liquefy, and the liquid refrigerant is sent to the heat exchanger 14 on the inside to exchange heat with air. Let the car cool down. The gasified refrigerant that has passed through the heat exchanger 14 inside the vehicle is separated into gas and liquid by the accumulator 19, then returned to the compressor 12, and circulated again through the above-described route, thereby repeating the inside of the vehicle. Cool to the set temperature Ts.

In the cooling mode, the electromagnetic valves 6 and 7 in the cooling water circulation circuit 2 of the vehicle driving engine 1 are closed, so that the cooling water is supplied to the vehicle driving engine 1 and the radiator 3.
Circulate only between and.

On the other hand, in step S2 described above, "Y
In the case of "ES", that is, when the in-vehicle temperature Ti is lower than the set temperature Ts (Ti <Ts), the mode is shifted to the heating mode, and the water supply pump 4 is operated (step S4). Then, by reading the signal output from the water temperature sensor 35,
The cooling water temperature Tw of the vehicle drive engine 1 is detected (step S5), and the cooling water temperature Tw becomes Tw <40 ° C.
It is determined which of the temperature ranges 0 ° C> Tw ≧ 40 ° C and Tw ≧ 70 ° C (step S6).

In step S6, Tw <40 ° C.
If determined, the air conditioning engine 24 is started to operate the compressor 12 of the heat pump 10 (step S7). Then, it is determined whether or not the outside temperature To detected by the outside temperature sensor 33 is 0 ° C. or less (step S8). If it is determined that To ≦ 0 ° C., the process proceeds to step S9, and the inside temperature sensor 34 It is determined whether or not the in-vehicle temperature Ti detected in the step is not more than 20 ° C. Where To ≦ 2
If it is determined that the temperature is 0 ° C., the mode shifts to the low temperature heating start-up mode (step S10).

In the low-temperature heating start-up mode, the high-temperature and high-pressure refrigerant discharged from the compressor 12 is indicated by arrows in FIG. 5 by opening the solenoid valves 20 and 22 and closing the solenoid valves 21 and 23. As shown, the heat exchanger 1 inside the vehicle
4 → Electron expansion valve 15 → Cooling water heat recovery heat exchanger 9 → Exhaust heat recovery heat exchanger 17 → Accumulator 19 → Compressor 12 As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 12 is radiated by the in-vehicle heat exchanger 14 to heat the inside of the vehicle.

Further, in the low temperature heating start-up mode,
The electromagnetic valve 7 is opened, the electromagnetic valve 6 is closed, and the cooling water of the vehicle driving engine 1 is supplied to the vehicle driving engine 1 → the defroster 5 → the cooling water heat recovery as shown by the one-dot chain line arrow in FIG. The heat is circulated through the path from the heat exchanger 9 to the vehicle driving engine 1. As a result, the cooling water has the function of absorbing the heat radiation of the vehicle drive engine 1 and recovering the heat into the refrigerant in the cooling water heat recovery heat exchanger 9.

Further, in the low temperature heating start-up mode, the solenoid valve 28 is opened and the solenoid valve 29 is closed, and the cooling water of the air conditioning engine 24 is discharged as shown by a dotted arrow in FIG. The exhaust heat exchanger 26 → the heat exchanger 17 for exhaust heat recovery → the air circulation engine 24 is naturally circulated through the route.
As a result, the cooling water absorbs the heat of the air conditioning engine 24 and the heat of the exhaust gas, and transfers the heat to the heat exchanger 1 for exhaust heat recovery.
In step 7, the refrigerant is recovered. Further, in order to increase the amount of heat recovered by the refrigerant, the exhaust throttle device 31 is operated to narrow the exhaust passage, and the exhaust pressure (the air conditioning engine 24) is reduced.
To increase the exhaust heat temperature and thus the cooling water temperature . Then, the rotation speed of the air conditioning engine 24 (the rotation speed of the compressor 12) is maximized to maximize the circulation capacity of the refrigerant and the amount of heat exhausted from the air conditioning engine 24, and the rotation speed of the fan 40 is maximized, so that the The maximum amount of hot air blown out is also maximized (step S11).

When the vehicle interior temperature Ti becomes higher than 20 ° C. by the heating operation in the low temperature heating start-up mode, the determination in step S9 becomes “NO” and the process proceeds to step S12. Here, the exhaust throttle device 31 is turned off, and the exhaust pressure (load of the air conditioning engine 24) is returned to a normal state. However, the circulation path of the refrigerant and the circulation of the cooling water of the vehicle drive engine 1 and the air conditioning engine 24 are performed. The route is the same as the low-temperature heating start-up mode described above. However, the amount of hot air and the number of revolutions of the compressor 12 correspond to the outside temperature To and the inside temperature T.
i and the set temperature Ts to control the vehicle interior temperature Ti (step S13).

On the other hand, if the determination in step S8 is "NO", that is, the outside air temperature To> 0 ° C. and the cooling water temperature Tw <40.
° C, the process proceeds to step S14, where the in-vehicle temperature Ti
Is 20 ° C. or less. If Ti ≤2
If it is 0 ° C., the process proceeds to step S15, where the solenoid valves 7,
28 is opened and the solenoid valves 6, 29 are closed. Thereby, the circulation path of the cooling water of the vehicle drive engine 1 and the air conditioning engine 24 becomes the same as the low-temperature heating start-up mode described above. Then, the solenoid valves 20 and 22 are opened and closed at a predetermined cycle, and synchronized with this, the solenoid valves 2 and 22 are opened.
Close and open 1,23. Thereby, the circulation path of the refrigerant is alternately repeated between the path 11b passing through the heat exchanger 9 for cooling water heat recovery and the heat exchanger 17 for exhaust heat recovery and the path 11a passing through the heat exchanger 16 on the outside of the vehicle. Can be switched.

In this case, when the refrigerant is circulated through the passage 11b passing through the heat exchanger 9 for recovering the cooling water heat and the heat exchanger 17 for recovering the exhaust heat, the refrigerant uses the exhaust heat of the vehicle driving engine 1 and the air conditioning engine 24. Is collected. On the other hand, when the refrigerant is circulated in the path 11a passing through the vehicle-side heat exchanger 16, the heat of the outside air is absorbed by the refrigerant in the vehicle-side heat exchanger 16 and used for heating. At this time, the cooling water heat recovery heat exchanger 9
And the refrigerant remaining in the exhaust heat recovery heat exchanger 17 passes through the check valve 18 of the bypass passage 11c, flows into the discharge pipe 12a side of the compressor 12, and is driven by the discharge pressure of the refrigerant in the discharge pipe 12a. It is sent to the inner heat exchanger 14 side.
This prevents the residual refrigerant from being overheated in the cooling water heat recovery heat exchanger 9 and the waste heat recovery heat exchanger 17,
Improve heating efficiency.

In this operation mode, the rotation speed of the air conditioning engine 24 (the rotation speed of the compressor 12) is maximized, and the rotation speed of the fan 40 is maximized, as in the low temperature heating start-up mode described above. The amount of hot air to be blown out is also maximized (step S16).

If the inside temperature Ti exceeds 20 ° C. due to this heating, the determination in step S14 becomes “NO”, and the process proceeds to step S17. Here, the solenoid valves 21 and 23
, The solenoid valves 20 and 22 are closed, and the high-temperature and high-pressure refrigerant discharged from the compressor 12 is supplied to the heat exchanger 14 inside the vehicle → the electronic expansion valve 15 → outside the vehicle as shown by arrows in FIG. Circulation is performed in the route of the heat exchanger 16 → the accumulator 19 → the compressor 12. Thereby, the high-temperature and high-pressure gas refrigerant discharged from the compressor 12 is radiated by the heat exchanger 14 on the inside of the vehicle, thereby heating the inside of the vehicle and absorbing heat of the outside air into the refrigerant by the heat exchanger 16 on the outside of the vehicle. Use it for heating.

Further, in this operation mode, the electromagnetic valve 29 is opened, the electromagnetic valve 28 is closed, and the cooling water of the air-conditioning engine 24 is supplied to the radiator 2 as shown by a dotted arrow in FIG.
The heat is radiated by natural circulation in the path 25b on the seventh side. Also,
The electromagnetic valve 6 is opened, the electromagnetic valve 7 is closed, and the cooling water of the vehicle driving engine 1 is supplied to the vehicle driving engine 1 → the defroster 5 → the hot water heater 8 → the vehicle as shown by a dashed line arrow in FIG. Circulate in the path of the driving engine 1. As a result, the cooling water is radiated by the hot water heater 8, and the inside of the vehicle is heated by both the hot water heater 8 and the heat exchanger 14 inside the vehicle. At this time, the temperature control is performed by controlling the amount of hot air and the rotation speed of the compressor 12 based on the outside temperature To, the inside temperature Ti, and the set temperature Ts (step S).
18).

On the other hand, as the heating operation time elapses, the cooling water temperature Tw of the vehicle driving engine 1 increases to 70 ° C.
> Tw ≧ 40 ° C., from step S6 to step S
The program proceeds to 19 where it is determined whether or not the outside temperature To is equal to or lower than 0 ° C. If To ≦ 0 ° C., step S2
The process proceeds to 0, and the air conditioning engine 24 is started. Then, the temperature Tf of the warm air blown out from the in-vehicle heat exchanger 14
Is detected by the blowout air temperature sensor 36 (step S2).
1) Compare the blown air temperature Tf with the cooling water temperature Tw (step S22).

If, in step S22, Tf <Tw
If it is determined, the process proceeds to step S23, where the solenoid valves 6, 21, 23, 29 are opened and the solenoid valves 7, 20, 2, 2 are opened.
Close 2,28. Thus, the refrigerant and the cooling water circulate in the path indicated by the arrow in FIG. 6, as in the case of step S17 described above. At this time, the temperature control is based on the outside air temperature To.
The control is performed by controlling the amount of hot air and the rotation speed of the compressor 12 based on the vehicle interior temperature Ti and the set temperature Ts (step S24).

If it is determined in step S22 that Tf ≧ Tw, the flow shifts to step S25 where the solenoid valves 7, 20, 2
The solenoid valves 6, 21, 23, 29 are closed by opening the solenoid valves 2, 28. Thereby, the refrigerant and the cooling water circulate along the path indicated by the arrow in FIG. 5, as in the case of step S10 described above. Also at this time, the air volume and the rotation speed of the compressor 12 are controlled by the outside temperature To, the inside temperature Ti, and the set temperature Ts (step S26).

On the other hand, at step S6, the cooling water temperature Tw ≧ 7
When it is determined that the temperature is 0 ° C., or when “N
When it is determined to be "O" (outside air temperature To> 0 ° C.), the process shifts to the normal heating mode in step S27. In this normal heating mode, the solenoid valve 6 is opened and the solenoid valve 7 is closed,
The cooling water is sent to the hot water heater 8 to heat the inside of the vehicle only by the heat radiation of the hot water heater 8. Therefore, the operation of the heat pump 10 remains stopped. The temperature control in the normal heating mode is performed by controlling the flow rate of the hot air and the flow rate of the cooling water based on the outside air temperature To, the inside air temperature Ti, and the set temperature Ts (step S28). At this time, the flow rate control of the cooling water
This is performed by controlling the rotation speed of the water pump 4.

According to the present embodiment described above, the interior of the vehicle is heated using the heat radiation of the cooling water of the engine 1 for driving the vehicle and the heat pump 10. Switches the circulation path of the cooling water of the vehicle driving engine 1 from the hot water heater 8 having a large amount of heat radiation to the cooling water heat recovery heat exchanger 9.
The heat radiation of the cooling water immediately after the start of the engine is reduced, the temperature rise of the cooling water (the temperature rise of the vehicle drive engine 1) can be accelerated, and the conventional preheater having a large capacity can be eliminated. As a result, fuel efficiency can be improved. In addition, since the heat radiation of the cooling water is collected by the refrigerant by the heat exchanger 9 for heat recovery of the cooling water, the heat radiation of the cooling water can be effectively used for heating by the heat pump 10.

Further, when the heating is started at a low temperature, the load of the air conditioning engine 24 for driving the compressor 12 of the heat pump 10 is temporarily increased by the exhaust throttle device 31 so that the exhaust heat temperature of the air conditioning engine 24 is increased. enhanced,
Since the waste heat absorbed by the cooling water of the air conditioning engine 24 is recovered by the waste heat recovery heat exchanger 17 into the refrigerant, the recovery of the heat radiation of the cooling water of the vehicle driving engine 1 described above, The heat energy transported by the refrigerant is greatly increased, and the heating capacity of the heat pump 10 is significantly increased, so that the heating rise at a low temperature can be accelerated.

Further, the heat pump 10 includes a four-way valve 13.
If the direction of circulation of the refrigerant in the refrigerant circulation circuit 11 is reversed by the switching of the above, it is possible to function as a refrigeration cycle for cooling the inside of the vehicle during cooling, so that one heat pump 10 can be used for both cooling and heating, Compared with a conventional structure having a refrigeration cycle dedicated to cooling and a large-sized preheater, the apparatus does not become large.

In this embodiment, an accumulator cycle is used as the heat pump 10, but it goes without saying that a receiver cycle may be used.

In this embodiment, the outside temperature To is set to 0 ° C.
Although the cooling water temperature Tw is compared with 40 ° C. and 70 ° C., it is needless to say that these determination reference values may be other temperatures.

Further, in this embodiment, as the exhaust heat temperature increasing means for increasing the exhaust heat temperature of the air conditioning engine 24 at the time of heating start at low temperature, the exhaust throttle device 31 for narrowing the exhaust passage.
However, for example, an exhaust brake system may be used.

In addition, the present invention can be variously modified, for example, a water supply pump may be provided in the cooling water circulation circuit 25 of the air conditioning engine 24, and the invention can be applied to vehicles other than large buses. .

[0042]

As is clear from the above description, the present invention heats the interior of a vehicle by utilizing the heat radiation of the cooling water of the engine for driving the vehicle and the heat pump. In this case, the cooling water circulation path of the vehicle drive engine is switched from the hot water heater, which has a large amount of heat radiation, to the cooling water heat recovery heat exchanger, and the load of the air conditioning engine is temporarily reduced by the exhaust heat temperature increasing means. By increasing the exhaust heat temperature of the air conditioning engine,
Since the waste heat absorbed by the cooling water is recovered by the refrigerant by means of a heat exchanger for recovering waste heat, the heating capacity of the heat pump can be effectively increased at the start of heating at a low temperature. In addition to improving heating efficiency at low temperatures and increasing the temperature rise after starting the vehicle drive engine, the fuel consumption can be improved in conjunction with the fact that conventional large-capacity preheating machines can be eliminated. Can be.

Moreover, the heat pump can function as a refrigeration cycle for cooling the interior of the vehicle during cooling if the direction of circulation of the refrigerant in the refrigerant circuit is reversed.
One heat pump can be used for both cooling and heating, and does not increase the size of the device.

[Brief description of the drawings]

FIG. 1 is a cycle configuration diagram of a vehicle air conditioner showing one embodiment of the present invention.

FIG. 2 is an electric circuit diagram related to air conditioning control.

FIG. 3 is a flowchart showing a flow of air conditioning control (part 1).

FIG. 4 is a flowchart showing a flow of air conditioning control (part 2).

FIG. 5 is a diagram showing the directions of circulation of refrigerant and cooling water when heating is started at a low temperature.

FIG. 6 is a diagram showing the directions of circulation of the refrigerant and the cooling water when heating is started at a normal temperature.

[Explanation of symbols]

1 is a vehicle drive engine, 2 is a cooling water circulation circuit, 3 is a radiator, 4 is a water pump, 5 is a defroster, 6 and 7 are solenoid valves, 8 is a hot water heater, 9 is a heat exchanger for cooling water heat recovery, 10 Is a heat pump, 11 is a refrigerant circuit, 12 is a compressor, 13 is a four-way valve, 14 is a heat exchanger inside the vehicle,
15 is an electronic expansion valve, 16 is a heat exchanger on the outside of the vehicle, 17 is a heat exchanger for recovering exhaust heat, 20 to 23 are solenoid valves, 24 is an air conditioning engine, 25 is a cooling water circulation circuit,
6 is an exhaust heat exchanger, 27 is a radiator, 28 and 29 are solenoid valves, 31 is an exhaust throttle device (exhaust heat temperature increasing means), 32
Denotes an air-conditioning control circuit (air-conditioning control means), 33 denotes a temperature sensor outside the vehicle, 34 denotes a temperature sensor inside the vehicle, 35 denotes a water temperature sensor, 36 denotes a temperature sensor for blowing air, and 40 and 41 denote fans.

Continuation of the front page (56) References JP-A-63-125429 (JP, A) JP-A 63-46209 (JP, U) JP-A 60-34538 (JP, U) JP-A 48-35864 (JP) , Y1) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60H 1/03 B60H 1/22 F25B 27/02

Claims (1)

(57) [Claims] A hot water heater provided in a cooling water circulation circuit for cooling an engine for driving the vehicle, for heating the inside of the vehicle by radiating the cooling water; A heat pump that radiates heat from the heat exchanger to heat the interior of the vehicle, an air conditioning engine that drives the compressor, and a cooling water circulation circuit that cools the air conditioning engine .
An exhaust heat recovery heat exchanger for recovering the exhaust heat of the air conditioning engine absorbed by the cooling water to the refrigerant; and a cooling water heat for recovering the heat radiation of the cooling water of the vehicle drive engine to the refrigerant. A heat exchanger for recovery, a valve for selectively switching a circulation path of the cooling water of the engine for driving the vehicle between the hot water heater side and the heat exchanger for cooling water heat recovery, and a load on the air conditioning engine. Means for increasing the exhaust heat temperature to increase the exhaust heat temperature; and, when heating is started at a low temperature, the cooling water circulation path of the vehicle driving engine is changed from the hot water heater side to the cooling water heat by the valve. The state is switched to the recovery heat exchanger side, and the exhaust heat temperature increasing means is operated to control to temporarily increase the load of the air conditioning engine.
An air conditioning system for a vehicle, comprising: an air conditioning control unit that raises the temperature of cooling water of an air conditioning engine .