JP6778871B2 - Vehicle air conditioner - Google Patents

Description

The present invention relates to a vehicle air conditioner.

Many vehicles equipped with an internal combustion engine heat the heater core of the air conditioner by the heat of the cooling water of the internal combustion engine, and during the heating operation, the heat of the heater core is exchanged with the air blown into the vehicle interior. ing.

In an internal combustion engine such as a diesel engine in which the combustion temperature is unlikely to be high, the temperature of the cooling water for cooling the internal combustion engine is also unlikely to be high. Therefore, in order to obtain a rapid increase in the heating temperature, a vehicle air conditioner to which an auxiliary heating system using a heat pump is added has been developed (see, for example, Patent Document 1).

This conventional vehicle air conditioner has a heater core that exchanges heat with the air blown into the vehicle interior, a cooling water passage that allows the cooling water of the internal combustion engine to flow into the heater core, and auxiliary heating that heats the cooling water that flows through the cooling water passage. It has a system. The auxiliary heating system has a refrigerant circuit having a compressor, a condenser, a heating expansion valve, and an evaporator. The auxiliary heating system takes out the heat of condensation of the high-temperature and high-pressure refrigerant flowing inside the condenser, and heats the cooling water flowing through the cooling water passage with the heat. The control device that controls the auxiliary heating system receives a detection signal from the water temperature sensor that detects the temperature of the cooling water flowing through the cooling water passage, and turns the compressor on and off and discharges the refrigerant so that the water temperature of the cooling water approaches the target temperature. The amount is controlled.

Japanese Unexamined Patent Publication No. 2014-172829

In the conventional vehicle air conditioner described above, the temperature of the cooling water flowing through the cooling water passage is detected by a water temperature sensor arranged at a position away from the heater core, and the compressor of the auxiliary heating system is turned on based on the detection result.・ Off and the amount of refrigerant discharged are controlled. Therefore, the temperature control by the auxiliary heating system tends to be delayed with respect to the temperature change of the cooling water actually flowing through the heater core.
Therefore, in the case of the conventional vehicle air conditioner described above, when the temperature of the condenser on the auxiliary heating system side suddenly changes for some reason, the temperature of the auxiliary heating system changes with respect to the accompanying change in the temperature of the cooling water. Recovery may be delayed and the temperature of the blown air blown into the passenger compartment may change suddenly, impairing the comfort of the occupants.

Therefore, the present invention is a vehicle capable of quickly recovering the change in the temperature of the cooling water flowing through the cooling water passage when the temperature of the condenser on the auxiliary heating system side changes during the heating operation using the auxiliary heating system. It is intended to provide an air conditioner for use.

The vehicle air conditioner according to the present invention adopts the following configuration in order to solve the above problems.
That is, the vehicle air conditioner according to the present invention has a heater core (for example, the heater core 19 of the embodiment) for heating the air blown into the room with the cooling water that has exchanged heat with the internal combustion engine (for example, the engine 4 of the embodiment). A condenser (for example, for example) that exchanges heat between the cooling water passage (for example, the cooling water passage 23A of the embodiment) and the refrigerant compressed by the compressor (for example, the compressor 13 of the embodiment) and the cooling water. A refrigerant circuit (eg, a refrigerant of the embodiment) having a sub-condenser 25 of the embodiment), a heating expansion valve (for example, the heating expansion valve 26 of the embodiment), and an evaporator (for example, the sub-evaporator 27 of the embodiment). An auxiliary heating system (for example, the auxiliary heating system 14 of the embodiment) having a circuit 30) and taking out the heat of condensation of the refrigerant flowing through the condenser to heat the cooling water flowing through the cooling water passage, and during the heating operation, In a vehicle air conditioner including a control device (for example, the control device 21 of the embodiment) that controls the auxiliary heating system so that the temperature of the cooling water flowing through the heater core approaches the target temperature, the control device is The temperature of the cooling water flowing through the heater core is determined based on the pressure information of the refrigerant flowing through the condenser, the operating state information of the compressor, the temperature information regarding the outside air temperature of the vehicle, and the vehicle speed information regarding the traveling speed of the vehicle. It is characterized in that the auxiliary heating system is controlled based on the estimated water temperature estimated here.

In this case, since the temperature of the cooling water flowing through the heater core is estimated in consideration of the outside air temperature and the traveling speed of the vehicle, which greatly affect the heat dissipation to the outside around the condenser, regardless of the outside air temperature and the operating condition of the vehicle, The temperature of the cooling water can be quickly and accurately recovered with respect to the temperature change on the condenser side.

According to the present invention, the temperature of the cooling water flowing through the heater core is estimated based on the pressure of the refrigerant flowing through the condenser , the operating state of the compressor, the temperature information regarding the outside air temperature of the vehicle, and the vehicle speed information regarding the traveling speed of the vehicle. Then, since the auxiliary heating system is controlled based on the estimated water temperature, when a temperature change occurs on the condenser side, the temperature of the cooling water is quickly recovered without a large delay in the temperature change of the cooling water. be able to.
Therefore, when the present invention is adopted, it is possible to prevent the temperature of the blown air blown into the vehicle interior from suddenly changing due to an unintended temperature change on the condenser side, and to improve the comfort of the occupant.

It is a perspective view which shows the vehicle which adopted the vehicle air conditioner which concerns on one Embodiment of this invention. It is a schematic block diagram of the air conditioner for vehicles which concerns on one Embodiment of this invention. It is a circuit diagram which shows the flow of the cooling water and the refrigerant at the time of the heating operation of the vehicle air conditioner which concerns on one Embodiment of this invention. It is a circuit diagram which shows the flow of the cooling water and the refrigerant at the time of the cooling operation of the air conditioner for a vehicle which concerns on one Embodiment of this invention. It is a graph which shows the estimated temperature of the cooling water, the actual cooling water temperature, and the temperature detected by the water temperature sensor together with the blowout temperature in the vehicle interior when the vehicle air conditioner according to the embodiment of the present invention is adopted.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a view of a vehicle 1 adopting the vehicle air conditioner 10 according to this embodiment as viewed from the upper right front side, and FIG. 2 is a diagram showing a schematic configuration of the vehicle air conditioner 10.
In the vehicle 1 according to this embodiment, as shown in FIG. 1, an engine room 3 is arranged in front of the vehicle interior 2, and an internal combustion engine 4 (hereinafter, referred to as "engine 4") is provided in the engine room 3. , The vehicle air conditioner 10 is arranged. The vehicle air conditioner 10 adjusts the temperature and humidity of the air blown into the vehicle interior (hereinafter referred to as "air conditioning air"), and also adjusts the air conditioning air blowing position, air volume, and operation mode (cooling, heating, dehumidification). , An air conditioning unit 11 for switching an operation mode such as ventilation) is provided.

As shown in FIG. 1, a radiator 5 for cooling the cooling water of the engine 4 is arranged in front of the engine 4 in the engine room 3, and a vehicle air conditioner 10 is arranged in front of the radiator 5. A condenser 12 which is an outdoor heat exchanger is arranged. Further, a compressor 13 and an auxiliary heating system 14, which will be described later, of the vehicle air conditioner 10 are arranged at a front right position of the engine 4 in the engine room 3.

In the vehicle 1 according to this embodiment, since the auxiliary heating system 14 is arranged at the front side position of the engine 4 together with the compressor 13, the auxiliary heating system 14 is installed at the rear position of the engine 4 in the engine room 3. As compared with the case of arranging the engine, a sufficient space can be secured between the partition wall separating the vehicle interior 2 and the engine compartment 3 and the engine 4. Therefore, when an impact load is input from the front of the vehicle, energy is easily absorbed on the front side of the partition wall.

Further, in the case of the vehicle 1 according to this embodiment, since the auxiliary heating system 14 is arranged close to the compressor 13 at the front side position of the engine 4, the piping distance between the compressor 13 and the auxiliary heating system 14 Can be shortened and the heat loss of the refrigerant in the piping can be reduced.

The air conditioning unit 11 is provided with an air introduction port 15a on the upstream side of the ventilation duct 15, and an air outlet 15b for blowing air conditioning air into the vehicle interior 2 on the downstream side. In the ventilation duct 15, a blower 16, an evaporator 17, a damper 18, and a heater core 19 are sequentially arranged from an air introduction port 15a toward an air outlet 15b. The air inlet 15a of the ventilation duct 15 is capable of switching the air taken into the inside to either inside air (in-vehicle air) or outside air (outside the vehicle interior).

The blower 16 is driven according to the applied drive voltage, and blows the air (inside air or outside air) introduced from the air introduction port 15a of the ventilation duct 15 toward the evaporator 17 and the heater core 19 in the ventilation duct 15. ..

The vehicle air conditioner 10 includes a main refrigerant circuit 20 including the evaporator 17. The main refrigerant circuit 20 includes a compressor 13, a condenser 12, an expansion valve 22, and an evaporator 17. The compressor 13 sucks the refrigerant from the evaporator 17, compresses the refrigerant, and discharges the refrigerant to the outdoor condenser 12. The compressor 13 is driven by control by the control device 21. The condenser 12 cools the refrigerant that has flowed into the inside by a running wind or a blower blown by a condenser fan (not shown). The expansion valve 22 decompresses the refrigerant flowing out of the condenser 12 to a low pressure to form a low-pressure gas-liquid two-phase state, and discharges the refrigerant to the evaporator 17 in the ventilation duct 15. The evaporator 17 cools the air in the ventilation duct 15 by the endothermic heat when the low-pressure refrigerant flowing into the evaporator evaporates.

The damper 18 in the ventilation duct 15 is rotated by a motor M driven by control by the control device 21, and of the air volume of the air that has passed through the evaporator 17 by the blower of the blower 16, the air volume introduced into the heater core 19. And the air volume ratio with the air volume bypassing the heater core 19 is adjusted by the opening degree.

In the heater core 19, the cooling water for cooling the engine 4 flows through the inside, and the heat of the cooling water heats the air in the passage toward the heater core 19 in the ventilation duct 15. The heater core 19 has a cooling water passage 23A on the supply side for flowing cooling water from a water jacket (not shown) in the engine 4 toward the heater core 19, and cooling on the return side for returning the cooling water from the heater core 19 to the water jacket in the engine 4. It is connected to the water passage 23B. In the cooling water passage 23A on the supply side, the cooling water heat-exchanged in the engine 4 is sent to the heater core 19, and the cooling water heat-exchanged with the air in the ventilation duct 15 in the heater core 19 is returned to the engine 4. A water pump 24 is interposed.

3 and 4 are circuit diagrams showing in detail the main refrigerant circuit 20 of the vehicle air conditioner 10 and the refrigerant and cooling water circuits of the auxiliary heating system 14. FIG. 3 shows the flow of the cooling water and the refrigerant during the heating operation with arrows, and FIG. 4 shows the flow of the cooling water and the refrigerant during the cooling operation with arrows. In addition, in FIGS. 3 and 4, detailed illustration of the ventilation duct 15 portion of the air conditioning unit 11 is omitted.
As shown in FIGS. 2 to 4, the vehicle air conditioner 10 includes an auxiliary heating system 14 that heats the cooling water flowing in the cooling water passage 23A on the supply side during the heating operation. The auxiliary heating system 14 heats the cooling water in the cooling water passage 23A in order to make up for the shortage of the temperature of the cooling water heated by the combustion heat of the engine 4 during the heating operation.

The auxiliary heating system 14 includes a compressor 13, a sub-condenser 25 (condenser), a gas-liquid separation tank 29, a heating expansion valve 26, and a refrigerant circuit 30 for auxiliary heating having a sub-evaporator 27 (evaporator). Have. In the case of this embodiment, the compressor 13 used in the refrigerant circuit 30 for auxiliary heating is shared with the compressor 13 used in the main refrigerant circuit 20 during cooling operation or the like. A part of the refrigerant passage is shared between the auxiliary heating refrigerant circuit 30 and the main refrigerant circuit 20, and the refrigerant passage connected to the shared refrigerant passage portion is separated by the switching valves 40 and 41 during the heating operation and the cooling operation. It can be changed. In FIG. 2, the circuit configuration of the common portion of the refrigerant passage of the auxiliary heating refrigerant circuit 30 and the main refrigerant circuit 20 is omitted and simplified.
During the heating operation, the compressor 13 sucks the refrigerant from the sub-evaporator 27, compresses the refrigerant to a high temperature and high pressure, and discharges the refrigerant to the sub-condenser 25.

Although detailed illustration of the sub-capacitor 25 is omitted, the capacitor body is formed of a layer made of a material having high thermal conductivity. A pipe on the downstream side of the compressor 13 of the auxiliary heating system 14 and a cooling water passage 23A on the supply side connected to the heater core 19 are fitted to the condenser main body in a penetrating state. In the sub-condenser 25, heat is taken from the high-temperature and high-pressure refrigerant that has flowed into the sub-condenser 25 from the compressor 13 to condense the gaseous refrigerant, and the heat (condensation heat) taken from the refrigerant is transferred to the cooling water passage on the upstream side of the heater core 19. It is transmitted to the cooling water flowing inside the 23A. As a result, the cooling water flowing inside the cooling water passage 23A is heated by the heat of the sub-condenser 25.

The gas-liquid separation tank 29 separates the gas-liquid of the refrigerant flowing out of the sub-capacitor 25 and flowing into the inside.
The heating expansion valve 26 decompresses the liquid refrigerant flowing out of the gas-liquid separation tank 29 to a low pressure to form a low-pressure gas-liquid two-phase state, and discharges the low-pressure refrigerant to the sub-evaporator 27.

Similar to the sub-capacitor 25, the sub-evaporator 27 is not shown in detail, but the evaporator body is formed of a layer made of a material having high thermal conductivity. A pipe on the downstream side of the heating expansion valve 26 of the auxiliary heating system 14 and a cooling water passage 23B on the return side connected to the heater core 19 are fitted to the evaporator main body in a penetrating state. In the sub-evaporator 27, the heat of the cooling water flowing in the cooling water passage 23B on the downstream side of the heater core 19 is absorbed by the endothermic action when the low-pressure refrigerant flowing into the inside evaporates. As a result, the temperature of the cooling water returned from the heater core 19 to the engine 4 through the cooling water passage 23B drops.

Further, in the cooling water passage 23A on the upstream side of the heater core 19, a condenser bypass passage 23A-b that bypasses the sub-condenser 25 is branched from the main passage 23A-m that penetrates the sub-condenser 25. A first bypass valve 31 whose opening degree is controlled by the control device 21 is interposed in the condenser bypass passage 23A-b. When the first bypass valve 31 completely closes the condenser bypass passage 23A-b, the entire amount of cooling water flowing through the cooling water passage 23A on the supply side flows to the sub-condenser 25 side. On the other hand, when the first bypass valve 31 is opened, the cooling water having a flow rate corresponding to the opening degree of the first bypass valve 31 passes through the condenser bypass passage 23A-b and flows to the sub-condenser 25 side by that amount. The flow rate decreases. At this time, the heat exchange efficiency on the sub-capacitor 25 side decreases, and as a result, the temperature drop of the refrigerant flowing in the sub-capacitor 25 is suppressed, and the temperature of the refrigerant flowing in the refrigerant circuit 30 for auxiliary heating rises.
When the temperature of the refrigerant flowing through the refrigerant circuit 30 rises in this way, the refrigerant pressure on the outlet side of the compressor 13 rises, and the work load of the compressor 13 increases.
Therefore, by opening the first bypass valve 31 under the control of the control device 21, the work load of the compressor 13 increases, so that the heating amount of the cooling water in the cooling water passage 23A on the supply side by the auxiliary heating system 14 increases. Therefore, the temperature of the conditioned air blown out from the air outlet 15b can be raised.
When raising the temperature of the conditioned air blown out from the air outlet 15b, the stopped compressor 13 is turned on, or the refrigerant discharge amount of the compressor 13 is increased when the compressor 13 is turned on. You may try to increase it.

In the cooling water passage 23B on the downstream side of the heater core 19, an evaporator bypass passage 23B-b that bypasses the sub-evaporator 27 is branched from the main passage 23B-m that penetrates the sub-evaporator 27. A second bypass valve 32 whose opening degree is controlled by the control device 21 is interposed in the evaporator bypass passage 23B-b. When the second bypass valve 32 completely closes the evaporator bypass passage 23B-b, the entire amount of cooling water flowing through the cooling water passage 23B on the return side flows to the sub-evaporator 27 side.
Further, when the second bypass valve 32 is opened, the cooling water having a flow rate corresponding to the opening degree of the second bypass valve 32 passes through the evaporator bypass passage 23B-b and flows to the sub-evaporator 27 side by that amount. The flow rate decreases. When the flow rate of the cooling water flowing to the sub-evaporator 27 side decreases, the heat of vaporization of the entire sub-evaporator 27 decreases, and the amount of vaporization from the liquid refrigerant decreases. As a result, the amount of the vaporized refrigerant is reduced, so that the work load of the compressor 13 is reduced.
Therefore, by opening the second bypass valve 32 under the control of the control device 21, the work load of the compressor 13 is reduced, so that the heating amount of the cooling water in the cooling water passage 23A on the supply side by the auxiliary heating system 14 is reduced. Therefore, the temperature of the conditioned air blown out from the air outlet 15b can be lowered.
When lowering the temperature of the conditioned air blown out from the air outlet 15b, the refrigerant discharge amount of the on-operating compressor 13 may be reduced or the operation of the compressor 13 may be stopped.

Further, the cooling water passage 23A on the supply side connected to the heater core 19 is provided with a water temperature sensor 33 that detects the temperature of the cooling water flowing in the cooling water passage 23A. The detection signal by the water temperature sensor 33 is input to the control device 21.

A pressure sensor 34 (refrigerant pressure detection unit) for detecting the pressure of the refrigerant flowing through the sub-capacitor 25 is arranged at an upstream position of the sub-capacitor 25 in the refrigerant circuit 30 of the auxiliary heating system 14. The detection signal by the pressure sensor 34 is input to the control device 21.
Further, the compressor 13 is provided with an operating state detecting unit 35 that detects an operating state of the compressor 13 such as an on / off state of the compressor 13 and a rotation speed, and outputs the signal to the control device 21. When the compressor 13 is a variable capacity compressor, the operating state detection unit 35 detects the current capacity of the compressor 13 and outputs the signal to the control device 21 as well.

Further, the vehicle 1 is provided with an outside air temperature sensor 36 (outside air temperature detection unit) for detecting the outside air temperature and a vehicle speed sensor 37 (vehicle speed detection unit) for detecting the traveling speed of the vehicle 1. Each detection signal detected by the outside air temperature sensor 36 and the vehicle speed sensor 37 is input to the control device 21.

In the vehicle air conditioner 10, the control device 21 controls the auxiliary heating system 14 so that the temperature of the cooling water flowing through the heater core 19 approaches the target temperature during the heating operation. The temperature control of the cooling water flowing through the heater core 19 is executed by any of the following (a) to (c) or any combination of (a) to (c).
(A) On / off control of the compressor 13.
(B) Control of increase / decrease in the amount of refrigerant discharged from the compressor 13.
(C) Open / close control of the first bypass valve 31 and the second bypass valve 32.
The temperature control of the heater core 19 during the heating operation is basically any of (a) to (c) or (a) to (c) so that the temperature detected by the water temperature sensor 33 matches the target temperature. However, in a situation where a sudden change in the cooling water temperature occurs due to an unintended sudden temperature change on the sub-condenser 25 side of the auxiliary heating system 14, the control device 21 is as follows. To correct (recover) the temperature change of the heater core 19.

That is, the control device 21 receives the detection signal from the pressure sensor 34 and the operation state detection unit 35, and constantly monitors the pressure of the refrigerant flowing through the sub-capacitor 25 and the operation state of the compressor 13, and the pressure sensor 34 Based on the detection information of the operating state detection unit 35, it is determined whether or not an unintended sudden temperature change on the sub-capacitor 25 side has occurred. When the control device 21 determines that an unintended sudden temperature change has occurred on the sub-capacitor 25 side, the control device 21 estimates the temperature of the cooling water flowing through the heater core 19 based on the detection information of the pressure sensor 34 and the operating state detection unit 35. To do. Then, the control device 21 controls the auxiliary heating system 14 by any of the above (a) to (c) or any combination of (a) to (c) based on the estimated temperature estimated here. Corrects (recovers) the temperature change of the heater core 19 by.

Further, the control device 21 receives detection signals from the outside air temperature sensor 36 and the vehicle speed sensor 37 of the vehicle 1, and corrects the estimated temperature of the cooling water flowing through the heater core 19 in consideration of these detection information. That is, when the outside air temperature is low or the vehicle speed is high, the amount of heat radiated to the outside from the sub-capacitor 25, piping, etc. increases, so the estimated temperature is corrected in consideration of the external heat radiating.

The estimated temperature T of the cooling water flowing through the heater core 19 can be derived using, for example, the following equations (1) and (2). Here, Pdx is the corrected pressure of the refrigerant, Psub is the pressure of the refrigerant flowing through the sub-condenser 25, Ncomp is the rotation speed of the compressor 13 (corresponding to the discharge amount of the refrigerant), Tamb is the outside air temperature of the vehicle, Vcar is the vehicle speed, and f. (X) is the refrigerant saturation temperature when the pressure of the refrigerant is x. Further, A, B, C and D are correction coefficients.
Pdx = Psub + A * Ncomp + B ... (1)
T = f (Pdx) + C * Tamb + D * Vcar ... (2)

Further, for the estimated temperature T of the cooling water flowing through the heater core 19, for example, a map showing the correspondence between the pressure of the refrigerant flowing through the sub-condenser 25 and the operating state of the compressor 13 is stored in the storage unit in advance, and the map is appropriately stored. You may ask by referring to. In this case, the estimated water temperature may be corrected by multiplying the estimated water temperature obtained by referring to the map by a coefficient according to the outside air temperature and the vehicle speed.

Further, when the condenser bypass passage 23A-b and the evaporator bypass passage 23B-b are opened by the first bypass valve 31 and the second bypass valve 32 during the heating operation, the condenser bypass passage 23A-b and the evaporator bypass passage are opened. The estimated water temperature deviates according to the proportion of the cooling water passing through the 23B-b. Therefore, when the condenser bypass passage 23A-b and the evaporator bypass passage 23B-b are open, the estimated water temperature is calculated by multiplying by a coefficient according to the opening degree of the first bypass valve 31 and the second bypass valve 32. You may try to correct it.

In FIGS. 3 and 4, the cooling water passage 42 and the water pump 43 are provided to circulate the cooling water between the water jacket and the radiator 5 in the engine 4. Switching valves 44 and 45 are provided in the cooling water passage 42 on the radiator 5 side and the cooling water passage 23B on the heater core 19 side, respectively. The opening / closing states of the switching valves 44 and 45 are appropriately switched by the control device 21 during the cooling operation and the heating operation.
Further, in FIGS. 3 and 4, the check valve 46 is interposed between the evaporator 17 of the main refrigerant circuit 20 and the compressor 13.

Subsequently, the operation of the vehicle air conditioner 10 according to this embodiment during the heating operation and the cooling operation will be described with reference to FIGS. 3 and 4.
(During heating operation)
During the heating operation, as shown in FIG. 3, the cooling water passage 42 on the radiator 5 side is closed by the switching valve 44, and the cooling water passage 23B on the heater core 19 side is opened by the switching valve 45. In this state, when the engine 4 is started and the water pump 24 is operated, the cooling water that cools the engine 4 is supplied to the heater core 19 through the cooling water passage 23A on the supply side, and the cooling water that has passed through the heater core 19 is the engine. It is returned to 4.

Further, during the heating operation, the main refrigerant circuit 20 is closed by the switching valve 41 in the downstream portion of the compressor 13, and the refrigerant circuit 30 for auxiliary heating is opened by the switching valve 40 in the downstream portion of the compressor 13. In this state, when the compressor 13 operates, the refrigerant circulates in the refrigerant circuit 30 for auxiliary heating, and the heat of condensation of the sub-condenser 25 is transferred to the cooling water passage 23A on the supply side to cool the cooling water in the cooling water passage 23A. The sub-evaporator 27 absorbs heat from the cooling water in the cooling water passage 23B on the return side. As a result, the temperature of the cooling water supplied to the heater core 19 is raised, and the shortage of combustion heat of the engine 4 is compensated.
The heater core 19 heated by the cooling water in this way exchanges heat with the conditioned air in the ventilation duct 15 of the conditioned unit 11 shown in FIG. As a result, the heating air is blown out from the air outlet 15b of the ventilation duct 15.
The temperature control of the cooling water during the heating operation is performed as described above.

(During cooling operation)
During the cooling operation, as shown in FIG. 4, the cooling water passage 23B on the heater core 19 side is closed by the switching valve 45, and the cooling water passage 42 on the radiator 5 side is opened by the switching valve 44. In this state, when the engine 4 is started and the waiter pump 43 is operated, the cooling water that cools the engine 4 is sent to the radiator 5 through the cooling water passage 42, and after the radiator 5 exchanges heat with the outside air, the engine 4 Returned to. As a result, the combustion heat of the engine 4 is released to the outside air through the radiator 5, and as a result, the overheating of the engine 4 is suppressed.

Further, during the cooling operation, the refrigerant circuit 30 for auxiliary heating is closed by the switching valve 40 in the downstream portion of the compressor 13, and the main refrigerant circuit 20 is opened by the switching valve 41 in the downstream portion of the compressor 13. When the compressor 13 operates in this state, the refrigerant circulates in the main refrigerant circuit 20, the refrigerant in the evaporator 17 absorbs heat from the surroundings, and the heat of the refrigerant in the condenser 12 is released to the outside.
At this time, the evaporator 17 exchanges heat with the conditioned air in the ventilation duct 15 of the conditioned unit 11 shown in FIG. As a result, the cooling air is blown out from the air outlet 15b of the ventilation duct 15.

As described above, in the vehicle air conditioner 10 according to this embodiment, the pressure of the refrigerant flowing through the sub-condenser 25 and the operating state of the compressor 13 are detected by the pressure sensor 34 and the operating state detecting unit 35, and the control device. 21 estimates the temperature of the cooling water flowing through the heater core 19 based on these detection information, and controls the auxiliary heating system 14 based on the estimated temperature. Therefore, when an unintended temperature change occurs on the sub-capacitor 25 side of the auxiliary heating system 14, the temperature of the cooling water can be quickly recovered without a large delay in the temperature change of the cooling water flowing through the heater core 19. Can be done.
Therefore, when the vehicle air-conditioning device 10 according to this embodiment is adopted, it is possible to prevent the temperature of the conditioned air from suddenly changing due to an unintended temperature change on the sub-capacitor 25 side. Therefore, the comfort of the occupant can be improved.

FIG. 5 is a graph showing a state of temperature change of each part when an unintended sudden drop in temperature occurs on the sub-capacitor 25 side of the auxiliary heating system 14 during the heating operation. (A) in the graph is the estimated temperature of the cooling water obtained as described above, and (B) is the actual temperature of the cooling water flowing through the heater core 19. Further, (C) in the graph is the temperature of the cooling water detected by the water temperature sensor 33.
As shown in this graph, a value closer to the temperature of the actual cooling water flowing through the heater core 19 when the above-mentioned estimated temperature is used as compared with the case where the water temperature sensor 33 having a slow detection characteristic for temperature change is used. Can be obtained.

Further, (D) in the graph of FIG. 5 is the blowout temperature of the air conditioning unit 11 when the estimated temperature is used, and (E) is the air conditioning when only the water temperature sensor 33 is used without using the estimated temperature. This is the blowout temperature of the unit 11.
As shown in this graph, when the auxiliary heating system 14 is controlled using the above-mentioned estimated temperature when there is an unintended sudden change in temperature on the sub-capacitor 25 side, the conditioned air suddenly changes. Fluctuations can be suppressed.

Further, in the vehicle air conditioner 10 according to this embodiment, the outside air temperature information by the outside air temperature sensor 36 and the vehicle speed information by the vehicle speed sensor 37 are input to the control device 21, and the pressure information of the refrigerant flowing through the sub-condenser 25 is used. The estimated temperature of the cooling water estimated based on the operating state information of the compressor 13 is corrected by adding the outside air temperature information by the outside air temperature sensor 36 and the vehicle speed information by the vehicle speed sensor 37. Therefore, the influence of the outside air temperature and the traveling speed of the vehicle, which are largely related to the amount of heat released from the periphery of the sub-capacitor 25 to the outside, can be reflected in the estimated temperature.
Therefore, when the vehicle air conditioner 10 according to this embodiment is adopted, the temperature of the cooling water is quickly and accurately adjusted with respect to the temperature change on the sub-condenser 25 side regardless of the outside air temperature and the operating speed of the vehicle. It can be recovered.

The present invention is not limited to the above embodiment, and various design changes can be made without departing from the gist thereof.

4 ... Engine (internal combustion engine)
10 ... Vehicle air conditioner 13 ... Compressor 14 ... Auxiliary heating system 19 ... Heater core 21 ... Control device 23A ... Cooling water passage 25 ... Sub condenser (condenser)
26 ... Expansion valve for heating 27 ... Sub-evaporator (evaporator)
30 ... Refrigerant circuit for auxiliary heating (refrigerant circuit)

Claims (1)

A cooling water passage that allows the cooling water that has exchanged heat with the internal combustion engine to flow into the heater core that heats the air that is blown into the room.
It has a refrigerant circuit having a condenser, a heating expansion valve, and an evaporator that exchange heat between the refrigerant compressed by the compressor and the cooling water, and takes out the heat of condensation of the refrigerant flowing through the condenser. An auxiliary heating system that heats the cooling water flowing through the cooling water passage,
In a vehicle air conditioner provided with a control device that controls the auxiliary heating system so that the temperature of the cooling water flowing through the heater core approaches the target temperature during the heating operation.
The control device flows through the heater core based on the pressure information of the refrigerant flowing through the condenser, the operating state information of the compressor, the temperature information regarding the outside air temperature of the vehicle, and the vehicle speed information regarding the traveling speed of the vehicle. An air conditioner for a vehicle, which estimates the temperature of cooling water and controls the auxiliary heating system based on the estimated water temperature estimated here.

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