JP3328466B2 - 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 an air conditioner for a vehicle in which a heat pump heats a passenger compartment or the like.

[0002]

2. Description of the Related Art In an electric vehicle which does not have an internal combustion engine such as an engine, since the hot water of a radiator cannot be used as a heating heat source, the interior of the vehicle compartment is heated by a heat pump system having an electric compressor or an electric heater. .

[0003]

By the way, in the above-mentioned heat pump system, if the heating operation is performed under the condition that the outside air temperature is low, the heat exchange in the outdoor heat exchanger becomes insufficient and the expected heat is pumped. In addition, the desired heating cannot be performed because the compressor is forcibly stopped, for example, by the pressure protection working with the decrease in the low pressure side pressure. On the other hand, the electric heater consumes a large amount of power, and thus has a problem that the traveling distance of the electric vehicle is significantly reduced.

In order to solve this problem, recently, a combustion heater is used as a heating heat source, and a heat medium such as water heated by the combustion heater is circulated through a heater core.
There has been proposed an apparatus capable of performing a heating operation without relying on a heat pump.

However, in the above-described apparatus, it is difficult for the user to separately execute the heating operation using the heat pump and the heating operation using the combustion heater, and the combustion heater is inadvertently heated even under the outside air temperature condition where the heating operation using the heat pump is possible. There is a problem that it is used as a heat source. Further, in the heating operation by the combustion heater, the combustion of the combustion heater is controlled so that the heat medium is maintained at a predetermined temperature. However, the capacity cannot be controlled at the time of stopping the combustion due to excessive capacity and at the time of a re-ignition step and the like. Stable heating capacity cannot be obtained. Furthermore, since the temperature of the heat medium rises more slowly than in the case where air is directly heated, the heating capacity tends to be insufficient immediately after startup.

The present invention has been made in view of the above circumstances, and a first object is to provide an air conditioner for a vehicle that can effectively use a combustion heater as a heating heat source.
A second object is to provide an air conditioner for a vehicle that can obtain stable heating performance even when a combustion heater is used as a heating heat source.

[0007]

According to a first aspect of the present invention, a combustion heater is provided as a heating heat source, and a heat medium for exchanging heat with conditioned air is shared with the combustion heater. In a heat pump type air conditioner for a vehicle, when the outside air temperature is equal to or lower than a first set temperature, the operation of the combustion heater is permitted, and a second setting in which the outside air temperature after the operation permission is higher than the first set temperature. If the temperature is equal to or less than the temperature, the operation permission state of the combustion heater is maintained, and heater operation restriction means for prohibiting the operation of the combustion heater when the outside air temperature after the operation permission exceeds the second set temperature is provided. Features.

According to a second aspect of the present invention, in the air conditioner for a vehicle according to the first aspect, when the outside air temperature is equal to or lower than the second set temperature at the time of starting the operation of the air conditioner, or after the air conditioner starts operating, Is provided with heater operation permitting means for permitting the operation of the combustion heater when the temperature becomes equal to or lower than the second set temperature.

According to a third aspect of the present invention, in the vehicle air conditioner according to the first or second aspect, when both the combustion heater and the heat pump are used as a heating heat source, the temperature of the heat medium is set to the first target temperature. When the temperature becomes higher than the first target temperature, the operation of the heat pump is stopped to operate the combustion heater alone, and the temperature of the heat medium is lower than the first target temperature.
And a heat source switching means for restarting the operation of the heat pump when the temperature falls below the target temperature.

According to a fourth aspect of the present invention, in the air conditioner for a vehicle according to the third aspect, when a combustion abnormality occurs in the combustion heater during the single operation of the combustion heater, the operation of the combustion heater is stopped to activate the heat pump. A second heat source switching means for operating independently is provided.

[0011] To achieve the second object, the present invention provides
The invention has a combustion heater as a heating heat source, and in a heat pump type vehicle air conditioner that shares a heat medium that exchanges heat with conditioned air with the combustion heater, a variable capacity heater is used as the combustion heater, When the combustion heater is used as a heating heat source, the capacity of the combustion heater is controlled so that the temperature of the heat medium becomes the first target temperature, and the combustion heater is in the minimum combustion state and the temperature of the heat medium is the first target temperature. A combustion control means for stopping combustion when the temperature exceeds the target temperature of the above, and combustion of the combustion heater when the temperature of the heat medium becomes equal to or lower than a second target temperature lower than the first target temperature after the combustion is stopped. Combustion restart means for restarting the fuel cell,
It is characterized by:

According to a sixth aspect of the present invention, in the air conditioner for a vehicle according to the fifth aspect, a heat quantity supplementing means for temporarily operating the heat pump between the time when the combustion heater enters the ignition step and the time when the combustion is ignited is provided. , Is characterized.

[0013]

According to the first aspect of the present invention, permission / non-permission of the operation of the combustion heater is determined in relation to the outside air temperature. It is not used as a heating heat source.

According to the second aspect of the present invention, immediately after the system is started, the operation permission condition of the combustion heater is shifted to the side where the outside air temperature is high, so that the immediate warming can be secured. Other functions are the same as those of the first aspect.

According to the third aspect of the present invention, when the heat load is high, both the combustion heater and the heat pump are used as the heating heat source, and when the heat load is low, the heating operation can be performed using only the combustion heater as the heating heat source. Other operations are the same as those of the first and second aspects of the present invention.

According to the fourth aspect of the present invention, when an abnormal combustion occurs during the single operation of the combustion heater, the heating operation can be continued by switching the heating heat source to the heat pump. Other functions are the same as those of the third aspect.

According to the fifth aspect of the present invention, the combustion capability and the combustion stoppage of the combustion heater during heating can be accurately controlled by the first and second target temperatures predetermined based on the temperature of the heat medium.

According to the sixth aspect of the invention, by temporarily using the heat pump as a heating heat source in the ignition step of the combustion heater, it is possible to suppress a decrease in the temperature of the heat medium during the time required for ignition. Other operations are the same as those of the fifth aspect.

[0019]

FIG. 1 shows the overall configuration of a vehicle air conditioner according to the present invention. In the figure, 1 is a variable capacity type electric compressor, 2 is an outdoor heat exchanger, 3 is an indoor heat absorber, 4
Is a water refrigerant heat exchanger, 5 is a heater core, 6 and 7 are thermal expansion valves, 8 to 11 are solenoid valves, 12 and 13 are check valves, 14
Denotes a liquid receiver, and these devices except the heater core 5 are connected by a refrigerant pipe to constitute a heat pump for both cooling and heating. 15 is a hot water pipe connecting the water refrigerant heat exchanger 4 and the heater core 5, 16 is a water supply pump interposed in the hot water pipe 15, and 17 is a built-in heat exchanger 17a containing a heat medium (water) flowing through the hot water pipe 15. This is a combustion heater that takes in and heats it.
18 is a temperature sensor for detecting the outlet water temperature Tw of the combustion heater 17, 19 is a temperature sensor for detecting the outlet temperature EVA · S of the indoor heat sink 3, and 20 is the outlet temperature MIX of the heater core 5.
-A temperature sensor that detects S. 21 is an air conditioning duct,
22 is a blower fan, 23 is an intake air switching damper, 24
Is an air mix damper, and the indoor heat exchanger 3 and the heater core 5 are arranged in an air conditioning duct 24.

FIG. 2 shows a control system configuration of the vehicle air conditioner. In the figure, 31 is a control unit of a microcomputer configuration, 32 is a drive unit for a compressor, 33
Is a drive unit for the solenoid valve, 34 is a drive unit for the water supply pump, 3
Reference numeral 5 denotes a driving unit for a combustion heater, and 36 denotes a driving unit for an air mix damper. Reference numerals 18, 19, and 20 denote the temperature sensors described above, 37 denotes an air conditioning temperature setter, and 38 denotes an outside air temperature Tam.
Is a temperature sensor for detecting the internal temperature (inside temperature) T
A temperature sensor 40 for detecting r, and a solar radiation sensor 40 for detecting the solar radiation. The control unit 31 stores in a memory a program for mode determination / startup, a program related to each mode operation, and the like.
To send a control signal.

The above-described combustion heater 17 enables operation in five combustion modes having different amounts of combustion. As shown in FIG. 3, each of the combustion modes 1 to 5 corresponds to the heater outlet water temperature Tw.
Are controlled by five temperatures Tw1 to Tw5 defined in advance. For example, if the heater outlet water temperature Tw is Tw
If it is 5 or less, mode 5 (maximum combustion mode) is selected, and if the heater outlet water temperature is between Tw2 and Tw1, mode 1 (minimum combustion mode) is selected. During operation in the minimum combustion mode, the heater outlet water temperature Tw becomes Tw1
When the temperature rises to (upper limit), the combustion is stopped.

The air conditioner for a vehicle according to the present embodiment is capable of operating mainly in the modes of cooling, heating and heater heating based on the mode judgment by the control section 31. The dehumidifying / cooling mode is operated by turning on a dry switch (not shown). In addition, mode operation of dehumidifying heating and heater dehumidifying heating is also possible. By the way, the following target outlet temperature TAO is TAO = Ks · Ts−
Kr ・ Tr-Kam ・ Tam-Krad ・ Trad + C
Where Ks is the air conditioning set temperature coefficient, Ts is the air conditioning set temperature, Kr is the inside air temperature coefficient,
Tr is the inside air temperature, Kam is the outside air temperature coefficient, Tam is the outside air temperature, Krad is the solar radiation coefficient, Trad is the solar radiation, and C is a constant.

The operation in the cooling mode is executed by closing the solenoid valves 8 and 9 and opening the solenoid valves 10 and 11. Refrigerant discharged from the compressor 1 flows into the outdoor heat exchanger 2 via the electromagnetic valve 10, and flows into the indoor heat absorber 3 via the check valve 12, the liquid receiver 14, the electromagnetic valve 11 and the expansion valve 6 and is compressed. Return to machine 1. At this time, the air mix damper 24 is in the fully closed position (the lower position in the figure), and the intake air from the blower fan 22 is cooled by the indoor heat absorber 3 and blown out into the vehicle interior. Also, at this time, the outlet temperature EV of the indoor heat absorber 3
The rotation speed of the compressor 1 is controlled so that A · S becomes the target blowout temperature TAO.

The operation in the dehumidifying / cooling mode is executed by closing the solenoid valve 9 and opening the solenoid valves 8, 10, and 11. A part of the refrigerant discharged from the compressor 1 flows into the outdoor heat exchanger 2 via the electromagnetic valve 10, and the other part of the discharged refrigerant flows into the water refrigerant heat exchanger 4 via the electromagnetic valve 8. The liquid receiver 14, the solenoid valve 11, and the expansion valve 6
And flows into the indoor heat absorber 3 to return to the compressor 1. In the water-refrigerant heat exchanger 4, heat exchange is performed between the refrigerant and water,
The heated hot water is sent to the heater core 5 through a hot water pipe 15 provided with a pump. At this time, the opening degree of the air mix damper 24 is controlled between the fully closed state and the fully opened state based on the ratio between the outlet temperature MIX · S of the heater core 5 and the target outlet temperature TAO. The air is dehumidified and cooled by the exchanger 3, and is heated by the heater core 5 and blown out into the vehicle interior. At this time, the rotation speed of the compressor 1 is controlled such that the outlet temperature EVA · S of the indoor heat absorber 3 becomes a preset target dehumidification temperature.

The operation in the heating mode is executed by closing the solenoid valves 10 and 11 and opening the solenoid valves 8 and 9. The refrigerant discharged from the compressor 1 flows into the water-refrigerant heat exchanger 4 via the electromagnetic valve 8, and flows into the outdoor heat exchanger 2 via the check valve 13, the liquid receiver 14 and the expansion valve 7, and And returns to the compressor 1. In the water-refrigerant heat exchanger 4, heat is exchanged between the refrigerant and water, and the heated hot water is sent to the heater core 5 through a hot water pipe 15 provided with a pump.
At this time, the air mix damper 24 is at the fully open position (upper position in the figure), and the intake air from the blower fan 22 is heated by the heater core 5 and blown out into the vehicle interior. At this time, the number of revolutions of the compressor 1 is controlled such that the outlet temperature MIX · S of the heater core 5 becomes the target outlet temperature TAO.

The operation in the dehumidifying and heating mode is executed by closing the solenoid valve 10 and opening the solenoid valves 8, 9, and 11. Refrigerant discharged from the compressor 1 flows into the water-refrigerant heat exchanger 4 via the solenoid valve 8, passes through the check valve 13 and the receiver 14, and is partially diverted. 6
, Flows into the indoor heat exchanger 3 and returns to the compressor 1,
The other part of the refrigerant flows into the outdoor heat exchanger 2 via the expansion valve 7 and returns to the compressor 1 via the electromagnetic valve 9. In the water-refrigerant heat exchanger 4, heat is exchanged between the refrigerant and water, and the heated hot water is sent to the heater core 5 through a hot water pipe 15 provided with a pump. At this time, the air mix damper 24 is in the fully open position (upper position in the drawing), and the intake air from the blower fan 22 is dehumidified by the indoor heat exchanger 3 and is heated by the heater core 5 and blown out into the vehicle interior. Further, at this time, the outlet temperature MIX · S of the heater core 5 becomes the target outlet temperature TA.
The rotation speed of the compressor 1 is controlled so as to be O.

The operation in the heater heating mode basically controls the combustion of the combustion heater 17 while controlling the combustion of the combustion heater 17 so that the outlet water temperature Tw of the combustion heater 17 becomes the target temperature.
This is performed by sending the hot water heated in step (1) to the heater core 5 through the hot water pipe 15 provided with the pump. When the heat load is high, the above-described heat pump heating is also used to secure the heat quantity. At this time, the opening degree of the air mix damper 24 is controlled between the fully closed state and the fully opened state based on the ratio between the outlet temperature MIX · S of the heater core 5 and the target outlet temperature TAO. And is blown out into the passenger compartment.

The operation of the heater dehumidifying and heating is executed by simultaneously performing the heater heating operation and the cooling operation. At this time, the air mix damper 24 is connected to the heater core 5.
The opening degree is controlled between the fully closed state and the fully opened state based on the ratio of the outlet temperature MIX · S to the target outlet temperature TAO, the intake air by the blower fan 22 is dehumidified by the indoor heat exchanger 3, and the heater core It is heated in 5 and blown out into the passenger compartment. At this time, the outlet temperature EVA of the indoor heat absorber 3
The compressor 1 is set so that S reaches a preset target dehumidification temperature.
Is controlled.

FIG. 4 shows a method of restricting the operation of the combustion heater 17 during the heating of the heater. Combustion heater 1
7 is predetermined in advance in relation to the outside air temperature as indicated by the solid line arrow in FIG. That is, the outside air temperature Tam becomes the first set temperature Tam1.
Operation is permitted in a temperature range from a lower value to the second set temperature Tam2, and the outside air temperature Tam is changed from a value higher than the second set temperature Tam2 to the first set temperature Tam2.
Operation is not permitted in the temperature range up to 1. However, at the start of the heater heating operation, the operation is permitted if the outside air temperature Tam is equal to or lower than the second set temperature Tam2, as indicated by the dashed arrow in the figure.

That is, permission / non-permission of the operation of the combustion heater 17 is determined in relation to the outside air temperature.
The combustion heater 17 is not inadvertently used as a heating heat source under the outside air temperature condition that allows the heating operation by the heat pump. Further, at the start of the heating operation, the range of the outside air temperature at which the operation of the combustion heater 17 is permitted can be expanded to the outside air temperature at which the heater operation is not permitted at the time of the normal operation, so that immediate heating at the start of heating can be achieved. Thus, the combustion heater 17 as a heating heat source can be effectively used, and the fuel consumption in the combustion heater 17 and the power consumption by the heat pump can be effectively suppressed.

FIG. 5 shows a method of using the heat pump at the time of heating the heater. As shown in the program flow in FIG. 6, the heat amount is supplemented by using the heat pump heating operation together with the start of the heater heating operation until the heater outlet water temperature Tw reaches the first target temperature Tws1. Then, the heater outlet water temperature Tw becomes equal to the first target temperature Tw.
After exceeding s1, the heater heating operation is performed alone. Under the single heater heating operation, the combustion performance of the combustion heater 17 is variably controlled (see FIG. 3) so that the heater outlet water temperature Tw becomes the first target temperature Tws1, and the heater outlet water temperature Tw is operated during the operation in the minimum combustion mode. Exceeds Tw1 (upper limit), the combustion of the combustion heater 17 is stopped. During the heater alone operation, the heater outlet water temperature Tw becomes equal to the first target temperature Tw.
When the temperature decreases to the second target temperature Tws2 lower than s1, the heat amount is supplemented by using the heat pump heating operation again. When a combustion abnormality occurs in the combustion heater 17, the operation of the combustion heater 17 is stopped and the heat pump heating operation is performed alone.

That is, when the heat load is high at the start of operation or the like, the amount of heat can be supplemented by using the heat pump heating operation together, so that the heater outlet water temperature Tw is quickly raised to the target water temperature to speed up the rise of the heating performance. it can. In addition, when the load is low, the heater heating operation can be performed alone to suppress power consumption accompanying the heat pump heating operation. Furthermore, even when the combustion heater 17 stops due to a combustion abnormality, the heating heat source is switched to the heat pump to continue the heating operation, thereby suppressing a decrease in the temperature of the blown air.

FIG. 7 shows a combined use method of the heat pump operation in the ignition step of the combustion heater 17. As shown in the program flow in FIG. 8, the combustion heater 17 enters the ignition step when the heater heating operation is started, but A1 is used together with the heat pump heating operation from the start of the ignition step until the actual ignition. The rise of the water temperature at time A1 is made faster. After the ignition of the combustion heater, the heat pump heating operation is stopped, and the heater heating operation is performed alone. Under the single heater heating operation, the combustion temperature of the combustion heater 17 is set so that the heater outlet water temperature Tw becomes the first target temperature Tws11.
Is controlled variably (see FIG. 3), and if the heater outlet water temperature Tw exceeds Tws11 (upper limit) during operation in the minimum combustion mode, the combustion of the combustion heater 17 is stopped. When the heater outlet water temperature Tw decreases to the second target temperature Tws12 due to the stop of the combustion, the combustion heater 17 starts the ignition step again. When the heater outlet water temperature Tw further decreases to the third target water temperature Tws13, the heat pump heating operation is restarted. The water temperature drop during the time A2 required for ignition is suppressed.

That is, by temporarily using the heat pump heating operation during the period from the start of the ignition step of the combustion heater 17 to the ignition, the water temperature is prevented from lowering in the ignition step, and the temperature of the blown air is reduced. Fluctuations can be suppressed.

The present invention is not limited to the vehicle air conditioner shown in the drawings, but can be applied widely to a heat pump type vehicle air conditioner in which a heat medium for exchanging heat with conditioned air is shared with a combustion heater. Can be obtained.

[0036]

As described above in detail, according to the first aspect of the present invention, it is possible to prevent the inadvertent use of the combustion heater as a heating heat source under the outside air temperature condition at which the heating operation by the heat pump is possible. The combustion heater as a heating heat source can be effectively used, and fuel consumption in the combustion heater and power consumption by the heat pump can be effectively suppressed.

According to the second aspect of the present invention, when the heating operation is started, the range of the outside air temperature at which the operation of the combustion heater is permitted is expanded to the outside air temperature at which the heater operation is not permitted during the normal operation, and the heating operation is started. Immediate warming can be achieved. Other effects are the same as those of the first aspect.

According to the third aspect of the present invention, the two heating heat sources can be effectively used in accordance with the heat load, and both the combustion heater and the heat pump are used as the heating heat source when the heat load is high. It is possible to speed up the rise of the heating performance immediately after the start of the heating operation. Other effects are the same as those of the first and second aspects of the invention.

According to the fourth aspect of the present invention, even when the combustion heater is stopped due to abnormal combustion, the heating heat source is switched to the heat pump to continue the heating operation, thereby suppressing a decrease in the temperature of the blown air. Other effects are the same as those of the third aspect.

According to the fifth aspect of the present invention, it is possible to precisely control the combustion capacity and the combustion stoppage of the combustion heater during heating, thereby obtaining an extremely stable heating capacity.

According to the sixth aspect of the present invention, it is possible to prevent the temperature of the heat medium from decreasing in the ignition step of the combustion heater and to suppress the fluctuation of the blown air temperature. Other effects are the same as those of the fifth aspect.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a vehicle air conditioner according to the present invention.

FIG. 2 is a control system configuration diagram of a vehicle air conditioner according to the present invention.

FIG. 3 is a diagram showing a combustion control method of a combustion heater.

FIG. 4 is a diagram showing a method for restricting operation of a combustion heater.

FIG. 5 is a timing chart showing a combined use of a heat pump operation during heater heating.

FIG. 6 is a flowchart of heat source switching control.

FIG. 7 is a timing chart showing a combined use method of a heat pump operation in an ignition step of a combustion heater.

FIG. 8 is a flowchart of heat quantity compensation control.

[Explanation of symbols]

1 ... electric compressor, 2 ... outdoor heat exchanger, 3 ... indoor heat absorber,
4—water refrigerant heat exchanger, 5—heater core, 6, 7—expansion valve, 8-11—solenoid valve, 12, 13—check valve, 14—liquid receiver, 15—hot water line, 16—water pump , 17: combustion heater, 18-20: temperature sensor, 21: air conditioning duct,
22: blower fan, 23: intake air switching damper, 24
... air mix damper, 31 ... control unit, 32-36 ... drive unit, 37 ... air conditioning temperature setter, 38, 39 ... temperature sensor, 40 ... solar radiation sensor.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60H 1/03 B60H 1/00 101 B60H 1/22

Claims (6)

(57) [Claims] 1. A heat pump type vehicle air conditioner including a combustion heater as a heating heat source and sharing a heat medium for performing heat exchange with conditioned air with the combustion heater, wherein an outside air temperature is equal to or lower than a first set temperature. In this case, the operation of the combustion heater is permitted, and if the outside air temperature after the operation is permitted is equal to or lower than a second set temperature higher than the first set temperature, the operation of the combustion heater is maintained and the outside air after the operation is permitted is maintained. An air conditioner for a vehicle, comprising: heater operation restricting means for prohibiting operation of the combustion heater when the temperature exceeds a second set temperature. 2. The outside air temperature at the time of starting the operation of the air conditioner becomes the second temperature.
And a heater operation permitting means for permitting the operation of the combustion heater when the outside air temperature becomes equal to or lower than the second set temperature after the operation of the air conditioner is started. Item 4. The vehicle air conditioner according to Item 1. 3. When both the combustion heater and the heat pump are used as a heating heat source, when the temperature of the heat medium becomes higher than the first target temperature, the operation of the heat pump is stopped to operate the combustion heater alone. And a heat source switching means for resuming the operation of the heat pump when the temperature of the heat medium becomes equal to or lower than a second target temperature lower than the first target temperature. The air conditioner for vehicles according to any one of the preceding claims. 4. A second heat source switching means for stopping the operation of the combustion heater and operating the heat pump alone when a combustion abnormality occurs in the combustion heater during the single operation of the combustion heater. The vehicle air conditioner according to claim 3, wherein 5. A heat pump type vehicle air conditioner having a combustion heater as a heating heat source and sharing a heat medium for exchanging heat with conditioned air with the combustion heater, wherein a variable capacity type combustion heater is used. When the combustion heater is used as a heating heat source, the capacity of the combustion heater is controlled so that the temperature of the heat medium becomes the first target temperature. Combustion control means for stopping combustion when the temperature exceeds the first target temperature, and combustion of the combustion heater when the temperature of the heat medium becomes equal to or lower than a second target temperature lower than the first target temperature after the combustion is stopped. And a combustion resuming unit for resuming combustion. 6. The vehicle air conditioner according to claim 5, further comprising a heat quantity supplementing means for temporarily operating the heat pump during a period from a time when the combustion heater enters an ignition process to a time when the combustion heater is ignited.