JPH1142933A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a heating capacity at the rise of the heating operation of an overall air conditioner unit by suppressing the extra heat loss of the air heated by an evaporator used as a hot gas heater. SOLUTION: In an air conditioner unit 1 in which an evaporator 8 is arranged in an air conditioner duct 2 and a hot water heater 3 is arranged on the air downstream side of the evaporator, when a cooling water temperature (TW) detected by a cooling water temperature sensor 38 is as low as below a specified level, an A/M door 5 is set at a MAX.COOL position to prevent the air heated by the evaporator 8 from being cooled by a low temperature cooling water flowing into a hot water heater 3. By this, a heating capacity at the rise of heating operation is increased. When the cooling water temperature(TW) is as high as over a specified level, the A/M door 5 is set at a MAX.HOT position to further heat the air heated by the evaporator 8 by the hot air heater 3. By this, the heating capacity is increased.

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 heating a room, and more particularly to a high-temperature, high-pressure gas refrigerant discharged from a refrigerant compressor, which is guided to a refrigerant evaporator through a decompression device to evaporate the refrigerant. The present invention relates to an air conditioner for a vehicle in which air flowing in a duct is heated by a container.

[0002]

2. Description of the Related Art Conventionally, as a vehicle heating device, cooling water for cooling an internal combustion engine is guided to a hot water heater in a duct, and the hot water heater heats air flowing in the duct to heat the vehicle interior. Hot water heating systems are common. However, such a hot water type heating device has a low heating capacity when the internal temperature is started and the hot water type heating device is started when the outside air temperature is low and the cooling water temperature is low, that is, when the heating operation starts up. Have a problem that

[0003] In order to solve the above problems,
For example, in Japanese Unexamined Patent Publication No. Hei 5-223357, a high-temperature, high-pressure gas refrigerant (hot gas) discharged from a refrigerant compressor of a refrigeration cycle is guided to an evaporator in a duct via a decompression device, and the refrigerant is evaporated by the refrigerant evaporator. 2. Description of the Related Art There has been proposed a vehicle air conditioner (first conventional example) in which the air flowing through the inside is heated to assist the heating capacity of the hot water heater.

[0004] For example, in Japanese Patent Application Laid-Open No. Hei 6-135221, a refrigerant compressor, a decompression device, a refrigerant evaporator, an accumulator, and a refrigerant evaporator of a hot gas heater cycle of the refrigerant compressor and an accumulator are provided. By arranging a heat absorbing heat exchanger for absorbing heat of air to the refrigerant, the temperature and pressure of the refrigerant sucked into the refrigerant compressor by the heat absorbing action of the heat absorbing heat exchanger are increased to heat the hot water heater. 2. Description of the Related Art There has been proposed a vehicle air conditioner (second conventional example) which assists in performance.

[0005]

However, in the first conventional example and the second conventional example, the hot water heater is disposed downstream of the evaporator, so that the temperature of the cooling water is still low immediately after the internal combustion engine is started. (For example, below 10 ° C)
Even when the air is heated by the evaporator, most of the heat is taken by the hot water heater itself and the low-temperature cooling water flowing through the hot water heater. In other words, the heat capacity of the hot water heater hinders the start of the heating operation, and even if the hot gas is guided to the evaporator to assist the heating performance of the hot water heater, the effect of improving the heating performance of the entire apparatus cannot be obtained as expected. The problem has arisen.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the heating capacity of the entire apparatus at the start of heating operation by suppressing excess heat loss of the air heated by the first heat exchanger. An object of the present invention is to provide an air conditioner.

[0007]

According to the first aspect of the present invention, when the heating capacity of the second heating heat exchanger detected by the heating capacity detecting means is equal to or less than a predetermined heating capacity, the first heating capacity can be reduced.
By heating the air with the heating heat exchanger and controlling the transfer of heat from the heated air to the cooling water flowing through the second heating heat exchanger, The amount of heat of the air heated in the first heating heat exchanger, through which the discharged high-temperature, high-pressure gas refrigerant is led through the pressure reducing device, is taken by the low-temperature cooling water flowing into the second heating heat exchanger. I will not be told. That is, by reducing excess heat loss of the air heated by the first heating heat exchanger, it is possible to improve the heating capacity of the entire apparatus at the time of starting the heating operation.

According to the second aspect of the present invention, when the temperature of the cooling water detected by the cooling water temperature detecting means is equal to or lower than a predetermined value, the first heating is performed by setting the air mixing door to the maximum cooling position. All the air heated by the heat exchanger for bypass bypasses the second heat exchanger for heating. Thereby, the heat of the air heated by the first heating heat exchanger is not deprived by the low-temperature cooling water flowing into the second heating heat exchanger.
Thereby, the effect described in claim 1 can be achieved.

According to the third aspect of the present invention, when the temperature of the cooling water detected by the cooling water temperature detecting means is equal to or lower than a predetermined value, the valve device is closed, so that the cooling water having a lower temperature than the internal combustion engine is provided. Does not return to the second heating heat exchanger. Thus, by reducing the excess heat loss of the air heated by the first heating heat exchanger, the heating performance of the entire apparatus at the start of the heating operation can be improved.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

[Configuration of First Embodiment] FIGS. 1 to 4 show a first embodiment of the present invention.
FIG. 1 is a view illustrating an overall configuration of an air conditioner for a vehicle, and FIG. 2 is a view illustrating a control system of the air conditioner for a vehicle.

In the air conditioner for a vehicle according to the present embodiment, each air conditioning means (actuator) in an air conditioning unit (air conditioner unit) 1 for air conditioning the interior of a vehicle equipped with an engine (internal combustion engine) E as a main heat source for heating. Is controlled by an air conditioning control device (hereinafter, referred to as an air conditioning ECU) 10.

The air conditioning unit 1 includes an air conditioning duct 2 forming an air passage 11 for guiding conditioned air into a vehicle interior. An outside air suction port, an inside air suction port, and an inside / outside air switching door (all not shown) are provided on the most upstream side of the air conditioning duct 2, and a centrifugal blower B is provided on the downstream side of the air. ing. An air outlet 12 such as a defroster air outlet, a face air outlet or a foot air outlet, and a mode switching door (not shown) are provided at the most downstream side of the air conditioning duct 2.

Next, on the upstream side of the air from the air outlet 12,
The hot water heater 3 for reheating the air that has passed through the evaporator 8, which will be described later, is provided. The hot water heater 3 corresponds to a second heating heat exchanger of the present invention, and is provided in a cooling water circulation circuit 4 where a cooling water circulating flow is generated by a water pump (not shown) driven by the engine E. It is installed in. When the hot water valve 13 provided in the cooling water circulation circuit 4 opens, the hot water heater 3 recirculates the cooling water having absorbed the exhaust heat of the engine E, and reheats the air using the cooling water as a heating heat source. That is, a downstream heat exchanger (main heating device) that performs an air heating action.

Two air mixing doors (hereinafter referred to as A / M doors) 5 are rotatably mounted on the upstream side and downstream side of the hot water heater 3. These A / M doors 5 are driven by a servo motor (not shown), and adjust the amount of air passing through the hot water heater 3 and the amount of air bypassing the hot water heater 3 depending on the stop position. Air heating degree adjusting means for changing the heating degree.

The two A / M doors 5 are set at the MAX / COOL position (maximum cooling position) where all the air from the evaporator 8 is bypassed from the hot water heater 3 during the maximum cooling operation, and the evaporator during the maximum heating operation. 8 is set to the MAX HOT position (maximum heating position) where all of the air from 8 passes through the hot water heater 3. Here, these engine E, hot water heater 3, cooling water circulation circuit 4, two A
The / M door 5 and the hot water valve 13 constitute a hot water heating device (main heating device) 6.

Next, between the centrifugal blower B and the hot water heater 3, an evaporator (refrigerant evaporator) 8, which is a component of the refrigeration cycle 7 mounted on the automobile, is connected to the air conditioning duct 2.
It is arranged so as to cover the entire surface of the air passage 11 inside. The refrigeration cycle 7 includes a first refrigerant circulation circuit (hereinafter referred to as a refrigeration cycle circuit) 21, a second refrigerant circulation circuit (hereinafter referred to as a hot gas heater circuit) 22, a refrigeration cycle circuit 21 and a hot gas heater circuit 22. The first to switch,
Second solenoid valves 23 and 24 are provided.

The refrigeration cycle circuit 21 includes a compressor 9
The high temperature, high pressure gas refrigerant discharged from the first solenoid valve 2
3 → condenser (refrigerant condenser) 25 → receiver (gas-liquid separator) 26 → expansion valve (decompression means) 27 → evaporator 8
→ A refrigerant circuit which circulates in the order of the accumulator (gas-liquid separator) 28 and the compressor 9. Further, the hot gas heater circuit 22 converts the high-temperature, high-pressure gas refrigerant (hot gas) discharged from the compressor 9 into the second solenoid valve 2.
The refrigerant circuit circulates in the order of 4 → pressure reducing device 29 → evaporator 8 → accumulator 28 and compressor 9.

When the first solenoid valve 23 opens and the second solenoid valve 24 closes, the refrigeration cycle circuit 2
In 1 the refrigerant circulates. In addition, the refrigeration cycle 7 includes the first
When the solenoid valve 23 closes and the second solenoid valve 24 opens, the refrigerant flows back into the hot gas heater circuit 22. The first and second solenoid valves 23 and 24 constitute a circulation circuit switching unit.

The evaporator 8 includes a refrigeration cycle circuit 21
When the refrigerant flows through the inside, it functions as a cooling heat exchanger that evaporates the low-temperature gas-liquid two-phase refrigerant flowing from the expansion valve 27 and cools the passing air. The evaporator 8 further includes a first heating heat exchanger (auxiliary heating) that evaporates a high-temperature gas-liquid two-phase refrigerant flowing from the pressure reducing device 29 and heats the passing air when the refrigerant flows in the hot gas heater circuit 22. The device works as a hot gas heater for the auxiliary heat source system. Here, the expansion valve 27 not only adiabatically expands the refrigerant but also adjusts the circulation amount of the refrigerant in accordance with the degree of superheat of the refrigerant at the outlet of the evaporator 8, and is a temperature-sensitive cylinder 27a for detecting the degree of superheat of the refrigerant. Is connected.

The compressor 9 corresponds to the refrigerant compressor of the present invention, and compresses and discharges the sucked refrigerant when the rotational power of the engine E of the automobile is transmitted. The compressor 9 is connected to an electromagnetic clutch 20 for interrupting transmission of rotational power from the engine E to the compressor 9. When the electromagnetic clutch 20 is energized (ON), the rotational power of the engine E is transmitted to the compressor 9, and the evaporator 8 performs an air cooling operation or an air heating operation. Also, the energization of the electromagnetic clutch 20 is stopped (OF
F), the engine E and the compressor 9 are shut off, and the air cooling or air heating by the evaporator 8 is stopped.

Next, the air conditioner ECU 10 will be described with reference to FIGS. An air conditioner ECU (corresponding to a heating control means of the present invention) 10 for controlling each air conditioner in the air conditioner unit 1 includes switches from respective switches on an air conditioner operation panel (not shown) provided on the front of the vehicle interior. A signal is input. In addition, on the air conditioner operation panel, a temperature setting switch (temperature setting means) 31 for setting the temperature in the passenger compartment to a desired temperature, an air conditioner switch 32 for instructing start or stop of the refrigeration cycle 7, and a centrifugal blower B A blower switch 33 for instructing ON and OFF is provided.

In the air conditioner ECU 10, C
A well-known microcomputer including a PU, a ROM, a RAM, and the like is provided, and each sensor signal from each sensor is A / D converted by an input circuit (not shown), and then input to the microcomputer. The air conditioner ECU is provided with an ignition switch (key switch) for starting and stopping the engine E of the automobile.
When DC power is supplied from a battery (not shown), which is an in-vehicle power supply mounted on the vehicle when is turned on (IG-ON), the control process is started.

The air conditioner ECU includes an inside air temperature sensor (inside air temperature detecting means) 34 for detecting the air temperature in the vehicle interior (hereinafter referred to as the inside air temperature) and an air temperature outside the vehicle interior (hereinafter referred to as the outside air temperature). An outside air temperature sensor (outside air temperature detecting means) 35 for detecting, an insolation sensor (insolation amount detecting means) 36 for detecting an amount of solar radiation entering the vehicle cabin, and an air temperature immediately after passing through the evaporator 8 (hereinafter referred to as an after-evaporation temperature To tell)
Post-evaporation temperature sensor (post-evaporation temperature detecting means) 3
7 and a cooling water temperature sensor (corresponding to a cooling water temperature detecting means of the present invention) 38 for detecting the temperature of the cooling water flowing into the hot water heater 3. The above-mentioned switches and sensors detect air-conditioning environmental factors necessary for air-conditioning the cabin of the automobile.

The post-evaporation temperature sensor 37 is a thermistor provided in the air passage 11 at a position directly downstream of the evaporator 8 on the downstream side of the evaporator 8 to detect the air temperature at this position. The post-evaporation temperature sensor 37 constitutes a first heating capacity (air heating degree) detecting means for detecting an actual heating capacity (air heating degree) by the evaporator 8 during the heating operation. The cooling water temperature sensor 38 corresponds to the heating capacity detecting means of the present invention, and utilizes a thermistor to detect the actual heating capacity (air heating degree) of the hot water heater 3 (second heating capacity (air heating)). Degree) constitutes a detecting means.

[Control Method of First Embodiment] Next, a heating operation control by the air conditioner ECU 10 of the present embodiment will be briefly described with reference to FIGS. Here, FIG. 3 is a flowchart showing a heating operation control method by the air conditioner ECU.

When the ignition switch is turned on (IG / O
N), when DC power is supplied to the air conditioner ECU 10, the routine of FIG. 3 is started. First, each switch signal is read from each switch on the air conditioner operation panel (step S1). Next, a control signal output to each air conditioner (actuator) is read (step S).
2). Specifically, a control signal (blower ON signal) output to a blower driving circuit (not shown) is read to detect the airflow level (blower level) of the centrifugal blower B. When the blower ON signal is read from the switch signal of the blower switch 33, the processing in step S2 is unnecessary.

Next, each sensor signal is read (step S3). More specifically, the inside air temperature (TR) detected by the inside air temperature sensor 34, the outside air temperature (TAM) detected by the outside air temperature sensor 35, the amount of solar radiation (TS) detected by the solar radiation sensor 36, the temperature sensor after evaporation The post-evaporation temperature (TE) detected at 37 and the coolant temperature (TW) detected by the coolant temperature sensor 38 are read.

Next, it is determined whether a blower ON signal has been input (step S4). If the determination result is NO, it is determined whether the ON condition of the refrigeration cycle 7 is satisfied. Specifically, it is determined whether or not a cooling environment mode or a dehumidification mode is a necessary temperature environment condition as the air conditioning mode (step S5). If the result of this determination is NO, the routine exits from the routine of FIG. Step S
If the determination result of step 5 is YES, the electromagnetic clutch 20 is energized (ON), the first electromagnetic valve 23 is opened, the second electromagnetic valve 24 is closed, and the refrigeration cycle circuit 21 7 is operated (step S6). Thereafter, the process exits the routine of FIG.

If the determination result of step S4 is YES, it is determined whether or not the outside air temperature (TAM) detected by the outside air temperature sensor 35 is lower than a predetermined temperature (for example, -5 ° C.). (Step S7). If the result of this determination is NO, the operation proceeds to the determination processing of step S5. If the determination result of step S7 is YES, it is determined whether the cooling water temperature (TW) detected by the cooling water temperature sensor 38 is lower than a predetermined temperature (for example, 80 ° C.) (step S7). S8). If the result of this determination is NO, the operation proceeds to the determination processing of step S5.

If the result of the determination in step S8 is YES, the electromagnetic clutch 20 is energized (ON), the first electromagnetic valve 23 is closed, the second electromagnetic valve 24 is opened, and the hot gas heater The refrigeration cycle 7 is operated by the circuit 22 (step S9). Next, by comparing the post-evaporation temperature (TE) detected by the post-evaporation temperature sensor 37 with the cooling water temperature (TW) detected by the cooling water temperature sensor 38, TE <TW × α
Is determined (step S10). Note that α
Is the conversion efficiency of water to air. In addition, the hot water heater 3
If the apparatus has an air temperature sensor that detects the air temperature (air temperature) immediately downstream of the air conditioner, the air temperature detected by the air temperature sensor and the post-evaporation temperature (TE) may be compared. good.

If the result of the determination in step S10 is YES, the heating capacity of the hot water heater 3 is large.
In order to use the evaporator 8 as a radiator of the auxiliary heating device, the A / M door 5 is placed in the MAX / HOT position (for example, SW).
= 100%) (step S11). Thereafter, the process exits the routine of FIG. If the determination result in step S10 is NO, the heating capacity of the hot water heater 3 is insufficient, so that the evaporator 8 is used as a radiator of the main heating device.
It is set to the OOOL position (for example, SW = 0%) (step S12). Thereafter, the process exits the routine of FIG.

[Operation of First Embodiment] Next, the operation of the vehicle air conditioner of this embodiment during the heating operation will be briefly described with reference to FIGS. Here, FIG. 4 is a time chart showing a change in the blow-out temperature at the start of the heating operation.

When the occupant operates the ignition switch to start the engine E to start the hot water heating device 6,
When the engine E is started and the hot water valve 13 is opened, the cooling water that has cooled the engine E through the cooling water circulation circuit 4 flows into the hot water heater 3 in the air conditioning duct 2. However, when the outside air temperature (TAM) is a low temperature equal to or lower than a predetermined value (for example, −5 ° C.), a predetermined time (for example,
(At the time of startup), the cooling water temperature is low, and the heating capacity of the hot water heater 3 is insufficient.

Therefore, the compressor 9 is operated (ON).
Then, the first solenoid valve 23 is closed and the second solenoid valve 24 is opened to switch the refrigeration cycle 7 from the refrigeration cycle circuit 21 to the hot gas heater circuit 22. Therefore, the high-temperature, high-pressure gas refrigerant (hot gas) compressed and discharged in the compressor 9 is depressurized by the decompression device 29 through the second solenoid valve 24 and flows into the evaporator 8 in the air conditioning duct 2. . The high-temperature refrigerant that has flowed into the evaporator 8 exchanges heat with air flowing in the air conditioning duct 2 toward the passenger compartment, evaporates and evaporates, and is then sucked into the compressor 9.

At this time, the air conditioner ECU 10
Temperature after evaporation (TE) detected by temperature sensor after evaporation 37
And the coolant temperature (TW) detected by the coolant temperature sensor 38
× α), the main heating capacity of the hot water heater 3 and the auxiliary heating capacity of the evaporator 8 are compared, and if it is determined that the main heating capacity of the hot water heater 3 is insufficient, A / M door 5 MAX ・ COOL
Set to position.

Then, all air heated by the high-temperature refrigerant flowing into the evaporator 8 is blocked by the A / M door 5 to the hot water heater 3, bypasses the hot water heater 3, and blows out from the outlet 12. It is blown out into the vehicle interior to heat the vehicle interior. If it is determined that the heating capacity of the hot water heater 3 is greater than the heating capacity of the evaporator 8, the A / M door 5 is set to the MAX / HOT position. Then, all the air heated by the high-temperature refrigerant flowing into the evaporator 8 passes through the hot water heater 3 and further rises in temperature, and is then blown out from the air outlet 12 into the vehicle compartment to heat the vehicle interior.

[Effects of the First Embodiment] Here, the result of an experiment in which the air temperature immediately downstream of the hot water heater 3 was detected by a temperature sensor is shown in the time chart of FIG. As shown by the solid lines in FIG. 4, the A / M door 5 is always
It can be confirmed that the air temperature (blowout temperature) immediately downstream of the hot water heater 3 is higher in the low temperature region than in the case of the position T (indicated by the dashed line in FIG. 4).
In the high temperature region, the air temperature immediately after the downstream of the hot water heater 3 (blowing temperature) is higher than when the A / M door 5 is always at the MAX COOL position (shown by a broken line in FIG. 4). Can be confirmed.

Therefore, in the air-conditioning unit 1 in which the hot water heater 3 is installed downstream of the evaporator 8 in the air-conditioning duct 2 as in the present embodiment, it takes too much time since the engine E is started. Even when the cooling water temperature (TW) is still low (for example, 10 ° C. or less), the air heated by the high-temperature refrigerant flowing into the evaporator 8 bypasses the hot water heater 3 and blows out into the vehicle interior. The heat of the air is not deprived by the hot water heater 3 itself and the low-temperature cooling water flowing into the hot water heater 3. That is, by preventing excess heat loss of the air heated by the evaporator 8 as an auxiliary heating device,
The heating capacity of the entire air conditioning unit 1 when the hot water heating device 6 starts up can be improved.

[Configuration of Second Embodiment] FIGS. 5 and 6 show a second embodiment of the present invention, and FIG. 5 is a diagram showing a control system of an air conditioner for a vehicle.

In the present embodiment, while the first embodiment employs the air mix temperature control method as the outlet temperature control method, the flow rate of the cooling water supplied to the hot water heater 3 is controlled by a flow control valve (W / V) A reheat-type temperature control system in which the temperature is controlled by adjusting the temperature at 30 is adopted. The flow control valve 30 corresponds to the valve device of the present invention, and is driven by a servomotor (not shown) to gradually or continuously change the cooling water passage of the cooling water circulation circuit 4 from a fully closed state to a fully opened state. It is changed to. In the case of this embodiment, two A / M doors 5 need not be provided.

[Control Method of Second Embodiment] Next, the heating operation control by the air conditioner ECU 10 of the present embodiment will be briefly described with reference to FIGS. Here, FIG. 6 is a flowchart showing a heating operation control method by the air conditioner ECU.

The same control processes as those in the flowchart of FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted. If the determination result in step S10 is YES, that is, if the cooling water temperature (TW × α) is higher than the post-evaporation temperature (TE), the heating capacity of the hot water heater 3 is large, so that the evaporator 8 is The flow control valve (W / V) 30 is opened for use as a radiator of the apparatus (step S)
13). Thereafter, the process exits the routine of FIG.

If the result of the determination in step S10 is NO, that is, the post-evaporation temperature (TE) becomes equal to the cooling water temperature (TW
Xα) or less, since the heating capacity of the hot water heater 3 is insufficient, the evaporator 8 is used as a radiator of the main heating device, so that the flow control valve (W / V) 3
0 is closed (step S14). Thereafter, the process exits the routine of FIG.

[Effects of the Second Embodiment] In the air conditioning unit 1 of the present embodiment, since the engine E is started, not much time has passed, and the cooling water temperature (TW) is still low (for example, 10 ° C or less). In the case of ()), the cooling water lower than the engine E does not flow into the hot water heater 3. As a result, when the air heated by the evaporator 8 passes through the hot water heater 3, only the heat is taken away by the surface temperature of the hot water heater 3 itself, and the excess heat loss of the air heated by the evaporator 8 is reduced. Therefore, the heating capacity of the entire air conditioning unit 1 when the hot water heating device 6 starts up can be improved.

[Other Embodiments] In the present embodiment, the present invention is applied to an air conditioner for a vehicle such as an automobile. However, the present invention may be applied to an air conditioner for an aircraft, a ship or a railway vehicle. . Further, the present invention may be applied to an air conditioner of a factory, a store, a house, or the like.

In the present embodiment, when the hot water heating device 6 starts up, the outside air temperature (TAM) and the cooling water temperature (T
Although the determination is made based on W), it may be determined whether or not the hot water heating device 6 is at the time of startup based on the elapsed time since the start of the internal combustion engine. Further, the inside air temperature (TR) is considerably lower than the set temperature (Tset) (for example, 10 ° C. to 20 ° C.).
° C) or the inside air temperature (TR) is a predetermined value (for example, 10
In the case of a low temperature of not more than (° C.), it may be determined that the hot water type heating device 6 is at the time of startup.

Here, in the case of an automatic air conditioner, when the target outlet temperature (TAO) is on the high temperature side, the refrigeration cycle 7
From the refrigeration cycle circuit 21 to the hot gas heater circuit 22
May be switched to. In the case of a manual air conditioner, set the temperature control lever to MAX.
When operated to the HOT position, the refrigeration cycle 7 may be switched from the refrigeration cycle circuit 21 to the hot gas heater circuit 22.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an overall configuration of a vehicle air conditioner (first embodiment).

FIG. 2 is a block diagram showing a control system of the vehicle air conditioner (first embodiment).

FIG. 3 is a flowchart showing a heating operation control method by the air conditioner ECU (first embodiment).

FIG. 4 is a time chart showing a change in blow-out temperature at the start of a heating operation (first embodiment).

FIG. 5 is a block diagram showing a control system of the vehicle air conditioner (second embodiment).

FIG. 6 is a flowchart showing a heating operation control method by the air conditioner ECU (second embodiment).

[Explanation of symbols]

 B Centrifugal blower E Engine (internal combustion engine) 1 Air conditioning unit 2 Air conditioning duct 3 Hot water heater (second heat exchanger) 4 Cooling water circulation circuit 5 A / M door 6 Hot water heating device 7 Refrigeration cycle 8 Evaporator (first) Heating heat exchanger) 9 Compressor (refrigerant compressor) 10 Air conditioner ECU (Heating control means) 11 Air passage 12 Blow outlet 13 Hot water valve 21 Refrigeration cycle circuit 22 Hot gas heater circuit 23 First solenoid valve 24 Second solenoid valve 29 Decompression Apparatus 30 Flow control valve (valve device) 37 Post-evaporation temperature sensor 38 Cooling water temperature sensor (heating capacity detecting means)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Kinoshita 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside DENSO Corporation

Claims (3)

[Claims] (A) a duct for sending air into a room; and (b) a refrigerant disposed in the duct and flowing through the duct, the refrigerant being discharged from a refrigerant compressor and flowing through a decompression device. A first heat exchanger for heating by exchanging heat with the first heat exchanger; and (c) cooling the internal combustion engine with air flowing in the duct, which is arranged in series with the first heat exchanger in the duct. A second heating heat exchanger for heating by exchanging heat with the cooling water; and (d) heating capacity detecting means for detecting a heating capacity of the second heating heat exchanger. When the detected heating capacity of the second heating heat exchanger is equal to or less than a predetermined heating capacity, the first heating heat exchanger heats air, and the heated air separates the second heating heat from the heated air. To reduce the heat transfer to the cooling water flowing through the exchanger Air conditioning apparatus and a heating control means for controlling. 2. The air conditioner according to claim 1, wherein an amount of air passing through the second heat exchanger and an amount of air bypassing the second heat exchanger are provided in the duct. An air mix door that adjusts the temperature of the cooling water, the heating capacity detecting means is a cooling water temperature detecting means for detecting a temperature of cooling water circulating through the second heating heat exchanger, and the heating controlling means is An air conditioner wherein the air mixing door is set to a maximum cooling position when the temperature of the cooling water detected by the cooling water temperature detecting means is equal to or lower than a predetermined value. 3. The air conditioner according to claim 1, wherein a valve device is provided in a cooling water circulation circuit that circulates cooling water from the internal combustion engine to the second heating heat exchanger. The heating capacity detecting means is a cooling water temperature detecting means for detecting a temperature of cooling water circulating through the second heating heat exchanger, and the heating control means is detected by the cooling water temperature detecting means. An air conditioner wherein the valve device is closed when the temperature of the cooling water is equal to or lower than a predetermined value.