JPH1142934A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an auxiliary heater which is easy to be mounted on a vehicle as a refrigerating cycle and by which a sufficient auxiliary heating capacity can be obtained even when the atmospheric temperature is as low as -10 deg.C or below. SOLUTION: A refrigerating cycle 6 is formed with a normal refrigerating cycle circuit 21, a hot gas heater circuit 22 in which high temperature and high pressure hot gas delivered from a compressor 8 is led to an evaporator 7 in an air conditioner duct 2 and air is heated by the hot gas, and first and second electromagnetic valves 23 and 24 which switch over these circuits. Also the hot gas heater circuit 22 is used as an auxiliary heater to supplement the heating capacity of a hot water type heater 3. In addition, an electric heater 9 to heat refrigerant is installed on the air upstream side of the evaporator 7 so as to raise the temperature and pressure of the refrigerant at the suction port side of the compressor 8 when the atmospheric temperature is as low as -10 deg.C or below to increase the auxiliary heating capacity by the evaporator 7 in the hot gas heater circuit 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner in which a high-temperature, high-pressure gas refrigerant discharged from a refrigerant compressor is led to a refrigerant evaporator through a decompression device and the air is heated by the refrigerant evaporator. More particularly, the present invention relates to a vehicle air conditioner mounted on a vehicle.

[0002]

2. Description of the Related Art Conventionally, a high-temperature, high-pressure gas refrigerant (hot gas) compressed and discharged by a refrigerant compressor is passed through a normal refrigeration cycle to a decompression device by bypassing a refrigerant condenser, and further, into a duct. A vehicle air conditioner (for example, Japanese Patent Application Laid-Open No. 5-223357: first conventional example) is provided with a hot gas heater cycle for supplying heat to a refrigerant evaporator and releasing heat therefrom, and then returning the refrigerant to a refrigerant compressor. Proposed.

In the first conventional example, during a heating operation, a refrigerant evaporator is used as a hot gas heater in addition to heating by a hot water heater of a hot water heating device using cooling water for cooling an internal combustion engine as a heat source for heating. This is a system that improves the heating capacity by assisting the hot water heating device. However, in a low-temperature environment where the outside air temperature is −10 ° C. or less, since the temperature and pressure of the refrigerant decrease and the specific volume increases, the mass flow rate of refrigerant sucked by the refrigerant compressor decreases, and the refrigerant compressor is not sufficiently cooled. Failure to perform the work caused a problem that the auxiliary heating capacity was insufficient.

Therefore, for the purpose of solving the above-mentioned problems,
For example, in Japanese Patent Application Laid-Open No. Hei 6-135221, a bypass pipe is attached between an outlet of a refrigerant evaporator and a suction port of a refrigerant compressor. 2. Description of the Related Art A vehicle air conditioner (second conventional example) including a hot gas heater cycle provided with a heat absorbing heat exchanger for heating a refrigerant has been proposed.

[0005]

However, in the second prior art, a bypass pipe, a heat absorbing heat exchanger, a solenoid valve for opening and closing the bypass pipe are provided in the hot gas heater cycle.
In addition, a fan and the like for blowing air from the passenger compartment to the heat exchanger for heat absorption are required, and the number of parts is large, the routing of the refrigerant pipe becomes very complicated, and it is difficult to mount the module on a passenger car. ing.

When the heating operation of the air conditioner for a vehicle is started (started) in a low temperature environment (extremely low outside air temperature) where the outside air temperature is -5 ° C. or lower, the air in the vehicle compartment is naturally taken. Is also as low as the outside air temperature. For this reason, even if the heat-absorbing heat exchanger is provided, the amount of heat obtained from the vehicle interior air is small, and the temperature and pressure of the refrigerant sucked into the suction port of the refrigerant compressor also become low. There is a problem that the auxiliary heating capacity is insufficient similarly to the hot gas heater cycle not provided.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an air conditioner equipped with an auxiliary heating device which can easily mount the auxiliary heating device on a vehicle or the like and can obtain a sufficient auxiliary heating capability even in a low temperature environment. Is to do.

[0008]

According to the first aspect of the present invention, a high-temperature, high-pressure gas refrigerant discharged from a refrigerant compressor is supplied to a refrigerant evaporator and then returned to the refrigerant compressor. In the heating device, by providing the refrigerant heating means, the refrigerant flowing in the refrigerant flow path from the inlet of the refrigerant evaporator to the suction port of the refrigerant compressor is heated, the temperature of the refrigerant sucked into the refrigerant compressor, Pressure rises.

As a result, the specific volume of the refrigerant sucked into the refrigerant compressor is reduced, and the refrigerant mass flow rate is increased, so that the refrigerant compressor can perform sufficient work. Ability is improved. Therefore, a sufficient auxiliary heating capacity can be obtained even in a low-temperature environment where the outside air temperature is extremely low. In addition, since the number of parts of the auxiliary heating device itself does not increase, the layout of the refrigerant pipes can be simplified, so that the mountability can be improved.

According to the invention described in claim 2, when the outside air temperature detected by the outside air temperature detecting means is equal to or lower than a predetermined temperature and the air heating degree detected by the heating degree detecting means is equal to or lower than a predetermined value, By operating the refrigerant heating means, it is possible to assist the heating capacity at the start of the heating operation of the main heating device.

According to the third aspect of the present invention, the air flowing through the duct is heated by the heat generated by the electric heater installed upstream of the refrigerant evaporator in the duct.
Since the refrigerant flowing into the refrigerant evaporator is heated by the high-temperature air, the temperature and pressure of the refrigerant sucked into the refrigerant compressor rise.

According to the fourth aspect of the present invention, by installing an electric heater in the suction pipe connecting the refrigerant evaporator and the refrigerant compressor, the refrigerant flowing in the suction pipe is heated by the electric heater. Therefore, the temperature and pressure of the refrigerant sucked into the refrigerant compressor rises.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

[Configuration of First Embodiment] FIGS. 1 to 5 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 conditioner (actuator) in an air conditioner 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 is provided with an air conditioning duct 2 forming an air passage for guiding conditioned air into the vehicle interior. At the most upstream side of the air conditioning duct 2, an outside air suction port, an inside air suction port, and an inside / outside air switching door (all not shown) are provided, and a centrifugal blower (not shown) is provided downstream of the air. ) Is provided. Further, on the most downstream side of the air conditioning duct 2, there are provided outlets such as a defroster outlet, a face outlet or a foot outlet, and a mode switching door (not shown).

Next, a hot water heater 4 of a hot water type heating device (corresponding to a main heating device of the present invention) 3 for reheating the air passing through an evaporator 7 described later is provided upstream of the air outlet from the air outlet. Have been. The hot water heater 4 is installed in a cooling water circulation circuit 5 in which a cooling water circulation flow is generated by a water pump (not shown) driven by the engine E. Then, the hot water heater 4 returns to the inside through the cooling water circulation circuit 5, the cooling water that has absorbed the exhaust heat of the engine E, and performs the second air heating operation of reheating the air using the cooling water as a heating heat source. This is a heating heat exchanger (downstream heat exchanger). Here, the engine E, the hot water heater 4 and the cooling water circulation circuit 5 constitute a hot water heating device 3.

Next, an evaporator (refrigerant evaporator) 7 which is a component of the refrigeration cycle 6 mounted on the vehicle is provided with an air passage in the air conditioning duct 2 upstream of the hot water heater 4 in the air conditioning duct 2. It is arranged so as to cover the entire surface. The refrigeration cycle 6 includes a refrigeration cycle circuit 21.
, Hot gas heater circuit 22 and refrigeration cycle circuit 2
1 and a first and second solenoid valves 23 and 24 for switching between the first and second hot gas heater circuits 22.

The refrigeration cycle circuit 21 corresponds to a cooling and dehumidifying device, and includes a high temperature discharged from the compressor 8,
The high-pressure gas refrigerant is supplied to the first solenoid valve 23 → condenser (refrigerant condenser) 25 → receiver (gas-liquid separator) 26 → expansion valve (decompression means) 27 → evaporator 7 → accumulator (gas-liquid separator) 28 and compressor Circulate in the order of 8. That is, when the first solenoid valve 23 opens and the second solenoid valve 24 closes, the refrigerant flows back into the refrigeration cycle circuit 21, so that the low-temperature, low-pressure liquid refrigerant is supplied to the evaporator 7. Is a refrigerant circuit in which the evaporator 7 performs an air cooling operation by supplying the air.

The hot gas heater circuit 22 corresponds to the auxiliary heating device of the present invention, and converts a high-temperature, high-pressure gas refrigerant (hot gas) discharged from the compressor 8 into a second electromagnetic valve 24 → a pressure reducing device 29 → an evaporator. 7 → circulate in the order of accumulator 28 and compressor 8. That is, the hot gas heater circuit 22 includes the first solenoid valve 23
Is closed and the second solenoid valve 24 is opened, the refrigerant is recirculated into the hot gas heater circuit 22 to supply a high-temperature gaseous refrigerant to the evaporator 7, so that the evaporator 7 performs air heating. Circuit. In addition,
The first and second solenoid valves 23 and 24 constitute a circulation circuit switching means.

The evaporator 7 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 7 also includes a first heating heat exchanger (auxiliary heat source) that evaporates the 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. Acts as a hot gas heater for the 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 7, and is a temperature-sensitive cylinder 27a for detecting the degree of superheat of the refrigerant. Is connected.

The compressor 8 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 8 is connected to an electromagnetic clutch 20 for interrupting transmission of rotational power from the engine E to the compressor 8. When the electromagnetic clutch 20 is energized (ON), the rotational power of the engine E is transmitted to the compressor 8, and the evaporator 7 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 8 are shut off, and the air cooling action or the air heating action by the evaporator 7 is stopped.

Next, an electric heater 9 for indirectly heating the refrigerant flowing into the evaporator 7 is provided upstream of the evaporator 7 in the air conditioning duct 2 so as to cover the entire surface of the air passage in the air conditioning duct 2. Are arranged. The electric heater 9 corresponds to the refrigerant heating means of the present invention. For example, a PTC heater (or nichrome wire heater) or the like is used, and the electric heater 9 is electrically connected to a battery 31 mounted on a vehicle via a fuse 32 and a relay circuit 33. Connected.
The battery 31 is electrically connected to an alternator 34 that is driven to rotate by the engine E and charges the battery 31. The relay circuit 33 includes a relay coil 33 that is turned on and off by the air conditioner ECU 10.
a, and a relay switch 33b that closes when the relay coil 33a is turned on.

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. A temperature control lever (temperature setting means) 41 for setting the temperature in the passenger compartment to a desired temperature, an air conditioner switch 42 for instructing start or stop of the refrigeration cycle 6, and an on / off of the centrifugal blower are provided on the air conditioner operation panel. Blower switch 4 to turn off
3 etc. are installed. Among them, the temperature control lever 41 commands the maximum cooling operation (MAX · COOL) when operated to one side, and the maximum heating operation (MAX · HOT) when operated to the other side.

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. When an ignition switch (key switch) for starting and stopping the engine E of the vehicle is turned on (IG / ON), the air conditioner ECU 10 receives a signal from a battery (not shown) which is a vehicle-mounted power supply mounted on the vehicle. The control processing is started when DC power is supplied.

The air conditioner ECU 10 has an inside air temperature sensor (inside air temperature detecting means) 44 for detecting the air temperature in the vehicle compartment (hereinafter referred to as the inside air temperature) and an air temperature outside the vehicle compartment (hereinafter the outside air temperature). An outside air temperature sensor (corresponding to the outside air temperature detecting means of the present invention) 45, a solar radiation sensor (insolation amount detecting means) 46 for detecting the amount of solar radiation entering the vehicle interior, and an air temperature immediately after passing through the evaporator 7 A post-evaporation temperature sensor (post-evaporation temperature detection means) 47 for detecting a post-evaporation temperature (hereinafter referred to as post-evaporation temperature), a cooling water temperature sensor (cooling water temperature detection means) 48 for detecting the temperature of the cooling water flowing into the hot water heater 4, Are input. 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 47 corresponds to the heating degree detection means of the present invention, and is provided in a portion of the air passage immediately downstream of the evaporator 7 to detect the air temperature in this portion. Thermistor.
The post-evaporation temperature sensor 47 constitutes a first heating capacity (air heating degree) detecting means for detecting an actual heating capacity (air heating degree) by the evaporator 7 during the heating operation.
The cooling water temperature sensor 48 uses a thermistor and constitutes second heating capacity (air heating degree) detecting means for detecting the actual heating capacity (air heating degree) of the hot water heater 4.

[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, FIGS. 3 and 4 are flowcharts showing a heating operation control method by the air conditioner ECU, and FIG. 5 is a graph showing a relationship between the outside air temperature and the heating capacity of each heating device.

When the ignition switch is turned on (IG / O
N), when the DC power is supplied to the air conditioner ECU 10, the routine of FIGS. 3 and 4 is started. First, each switch signal is read from each switch on the air conditioner operation panel (step S1). Specifically, an operation signal of the temperature control lever 41 is read.

Next, a control signal output to each air conditioner (actuator) is read (step S2). 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. When the blower ON signal is read from the switch signal of the blower switch 43, the processing in step S2 is unnecessary.

Next, each sensor signal is read (step S3). Specifically, the inside air temperature (TR) detected by the inside air temperature sensor 44, the outside air temperature (TAM) detected by the outside air temperature sensor 45, the amount of solar radiation (TS) detected by the solar radiation sensor 46, and the post-evaporation temperature sensor The post-evaporation temperature (TE) detected at 47 and the cooling water temperature (TW) detected by the cooling water temperature sensor 48 are read.

Next, it is determined whether a blower ON signal has been input (step S4). If this determination result is NO, it is determined whether the ON condition of the refrigeration cycle 6 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 FIGS.

If the determination result of step S5 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 is performed. The refrigeration cycle 6 is operated by the cycle circuit 21 (Step S6). Thereafter, the process exits from the routine of FIGS. In addition, the determination result of step S4 is YES
In the case of, MAX.
It is determined whether a HOT signal has been input (step S7). If the result of this determination is NO, step S5
It proceeds to the determination processing of.

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 48 is lower than a predetermined value (for example, 80 ° C.). (Step S8). This determination result is N
In the case of O, the process proceeds to the determination processing of step S5. Also,
If the determination result in step S8 is YES, it is determined whether or not the outside air temperature (TAM) detected by the outside air temperature sensor 45 is lower than a predetermined value (for example, −5 ° C.) (step S9). 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 S9 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 The refrigeration cycle 6 is operated by the gas heater circuit 22 (Step S10). Next, as shown in FIG. 4, based on the graph of FIG.
Determine F. Specifically, the outside air temperature (TAM) detected by the outside air temperature sensor 45 is a predetermined value (for example, −10 ° C.).
It is determined whether or not the temperature is below (step S1).
1). If the result of this determination is NO, an output is made to the relay circuit 33 so as to turn off the electric heater 9 (step S12). Thereafter, the process proceeds to the determination processing of step S15.

If the result of the determination in step S11 is YES
In the case of (1), it is determined whether or not the cooling water temperature (TW) detected by the cooling water temperature sensor 48 is lower than a predetermined value (for example, 50 ° C.) (Step S13). If the result of this determination is NO, the process proceeds to step S12. If the result of the determination in step S13 is YES, an output is made to the relay circuit 33 to turn on the electric heater 9 (step S14).

Next, it is determined whether or not the post-evaporation temperature (TE) detected by the post-evaporation temperature sensor 47 is higher than a predetermined temperature (for example, 50 ° C.) (step S15). If the determination is NO, the process returns to step S1. If the determination result of step S15 is YES, the energization of the electromagnetic clutch 20 is stopped (OFF) (step S16). Thereafter, the process exits from the routine of FIGS.

[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.

When the occupant operates the ignition switch to start the engine E to start the hot water type heating device 3, the hot water type heating device 3 cools the engine E through the cooling water circulation circuit 5 by starting the engine E. The cooled water flows into the hot water heater 4 in the air conditioning duct 2. However, the temperature control lever 41 is set to the MAX / HOT position, and the outside air temperature (TAM) is set to a predetermined temperature (for example,-
When the cooling water temperature (TW) is lower than a predetermined temperature (for example, 80 ° C.) or lower at a low temperature of 5 ° C. or lower, a predetermined time (for example, 5 minutes to 15 minutes) elapses after the engine E is started. Until (at startup) the cooling water temperature is low,
The heating capacity of the hot water heater 4 is insufficient. For this reason, the first electromagnetic valve 23 is closed, the second electromagnetic valve 24 is opened, the refrigeration cycle 6 is switched from the refrigeration cycle circuit 21 to the hot gas heater circuit 22, the compressor 8 is started, and the hot water heating apparatus is started. 3 heating capacity.

Therefore, the high-temperature, high-pressure gas refrigerant (hot gas) compressed and discharged in the compressor 8 is:
The pressure is reduced by the pressure reducing device 29 through the second solenoid valve 24 and flows into the evaporator 7 in the air conditioning duct 2. Then, the high-temperature refrigerant flowing into the evaporator 7 exchanges heat with the air flowing through the air conditioning duct 2 toward the vehicle interior, evaporates and evaporates, and is then sucked into the compressor 8. On the other hand, the air heated by the high-temperature refrigerant flowing into the evaporator 7 passes through the hot water heater 4 and is blown out from the air outlet into the vehicle interior to heat the vehicle interior.

At this time, as shown in the graph of FIG.
Even if the centrifugal blower (blower) is operated at a Hi air volume (maximum air volume), if the outside air temperature (TAM) is -10 ° C or lower and the cooling water temperature (TW) is 50 ° C or lower,
The main heating capacity of the hot water heating device 3 by the hot water heater 4 (cooling water) is added to the evaporator 7 of the hot gas heater circuit 22.
Even if the auxiliary heating capability by (hot gas) is added, the heating capability is lower than the required capability (dashed line in FIG. 5) required for heating the vehicle interior.

The reason is that the outside air temperature (TAM) is -10.
In a low temperature environment of not more than ℃, the evaporation temperature of the refrigeration cycle 6,
Since the evaporation pressure is low and the refrigerant specific volume on the suction side of the compressor 8 is large, the refrigerant weight flow rate is small,
Because compressor 8 does not do enough work,
This is because the auxiliary heating capacity (see the heating capacity when the electric heater is OFF shown by the solid line in FIG. 5) is insufficient.

In such a case, the electric heater 9 installed on the air upstream side of the evaporator 7 is operated (ON) to raise the temperature of the air that exchanges heat with the refrigerant in the evaporator 7, thereby increasing the temperature of the evaporator. 7 to increase the heat absorption. Thereby, the evaporating temperature and the evaporating pressure of the refrigeration cycle 6 are increased, and the compressor 8 performs sufficient work, so that the auxiliary heating capacity of the evaporator 7 of the hot gas heater circuit 22 is increased (see the dashed line in FIG. 5). (Refer to the heating capacity when the heater is ON)), so that the heating capacity of the air conditioning unit 1 increases.

[Effects of the First Embodiment] Therefore, in the present embodiment, even in a low temperature environment where the outside air temperature (TAM) is −10 ° C. or less and when the hot water type heating device 3 starts up, the hot gas heater circuit The heating capacity of the entire air conditioning unit 1 can be improved by increasing the auxiliary heating capacity of the evaporator 7. And
In the present embodiment, the hot gas heater circuit 22 does not require a bypass pipe, a heat exchanger for absorbing heat, an electromagnetic valve for opening and closing the bypass pipe, and a fan for blowing air from the passenger compartment to the heat exchanger for heat absorption. Since the number of points is small and the layout of the refrigerant pipes can be greatly simplified, the mountability on vehicles such as passenger cars can be improved.

When the temperature after heating (TE) rises to a predetermined temperature (for example, 50 ° C.) by operating (ON) the electric heater 9 during the heating operation of the air conditioning unit 1, In order to prevent the evaporating pressure of the refrigeration cycle 6 from excessively rising, the compressor 8 is turned off to stop the operation of the refrigeration cycle 6. For this reason, the auxiliary heating capacity of the evaporator 7 of the hot gas heater circuit 22 becomes excessive, and it is possible to prevent the temperature of the air blown from the air conditioning duct 2 into the vehicle compartment from overshooting, for example, a set temperature.

[Second Embodiment] FIG. 6 shows a second embodiment of the present invention and is a view showing the entire configuration of an air conditioner for a vehicle.

In the present embodiment, instead of the electric heater 9 that indirectly heats the refrigerant as in the first embodiment, an electric heater installed so as to be in contact with the outer periphery of the suction pipe 35 connecting the evaporator 7 and the accumulator 28 is used. The heater 9 is used. And the outside air temperature (TAM) is -10 ° C
Under the following low temperature environment, and at the time of startup of the hot water type heating device 3, the electric heater 9 directly heats the refrigerant flowing in the suction pipe 35, thereby reducing the temperature and pressure of the refrigerant on the suction port side of the compressor 8. I try to raise it.

[Other Embodiments] In this 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, a railroad vehicle, or the like. . Further, the present invention may be applied to an air conditioner of a factory, a store, a house, or the like.

In this embodiment, when the hot water type heating device 3 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 3 is starting up 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 3 is starting.

In this embodiment, the refrigeration cycle 6 is switched from the refrigeration cycle circuit 21 to the hot gas heater circuit 22 when the temperature control lever 41 is operated to the MAX / HOT position. The refrigeration cycle 6 may be switched from the refrigeration cycle circuit 21 to the hot gas heater circuit 22 when the target outlet temperature (TAO) is on the high temperature side.

In the present embodiment, the electric heater 9 is used as the refrigerant heating means. However, a combustion device such as a combustion heater may be used as the refrigerant heating means. Also, the installation location of the refrigerant heating means may be any location that can directly or indirectly heat the refrigerant flowing in the refrigerant flow path from the inlet of the evaporator 7 to the suction port of the compressor 8, Desirably, it may be installed at a place where the refrigerant flowing in the refrigerant flow path from the inlet of the evaporator 7 to the inlet of the accumulator 28 can be heated directly or indirectly.

In this embodiment, the electric heater 9, the evaporator 7, and the hot water heater 4 are arranged in this order from the air upstream to the air downstream in the air conditioning duct 2. However, the air downstream from the air upstream in the air conditioning duct 2. The hot water heater 4, the electric heater 9, and the evaporator 7 may be arranged in this order toward the side, or the electric heater 9, the hot water heater 4, and the evaporator 7 may be arranged in this order.

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

FIG. 5 is a graph showing a relationship between an outside air temperature and a heating capacity of each heating device (first embodiment).

FIG. 6 is a block diagram showing an overall configuration of a vehicle air conditioner (second embodiment).

[Explanation of symbols]

 E engine (internal combustion engine) 1 air conditioning unit 2 air conditioning duct 3 hot water heating device (main heating device) 4 hot water heater 5 cooling water circulation circuit 6 refrigeration cycle 7 evaporator (refrigerant evaporator) 8 compressor (refrigerant compressor) 9 electric heater ( Refrigerant heating means) 10 air conditioner ECU (heating control means) 21 refrigeration cycle circuit 22 hot gas heater circuit (auxiliary heating device) 23 first solenoid valve 24 second solenoid valve 29 pressure reducing device 45 outside air temperature sensor (outside air temperature detecting means) 47 ever Rear temperature sensor (heating degree detecting means)

Claims (4)

[Claims] 1. A duct for sending air into a room, (b) a main heating device for heating air passing through the duct, and (c) a refrigerant discharged from a refrigerant compressor, (D) an auxiliary heating device which supplies a refrigerant to a refrigerant evaporator disposed upstream of the main heating device in the duct and heats the air with the refrigerant evaporator and returns the air to the refrigerant compressor; An air conditioner comprising: a refrigerant heating unit that heats a refrigerant flowing in a refrigerant flow path from an inlet of the refrigerant evaporator to an inlet of the refrigerant compressor. 2. The air conditioner according to claim 1, further comprising: heating control means for controlling activation and stop of the refrigerant heating means, wherein the air conditioning control means detects an outside air temperature, and It has heating degree detecting means for detecting the degree of air heating by the refrigerant evaporator, and the outside air temperature detected by the outside air temperature detecting means is equal to or lower than a predetermined temperature, and the degree of air heating detected by the heating degree detecting means is An air conditioner characterized by operating the refrigerant heating means when the temperature is equal to or less than a predetermined value. 3. The air conditioner according to claim 1, wherein the refrigerant heating means is provided in the duct at an upstream side of the refrigerant evaporator with respect to the air, and air flowing toward the refrigerant evaporator. An air conditioner characterized by being an electric heater for heating air. 4. The air conditioner according to claim 1, wherein the refrigerant heating means is an electric heater that heats a refrigerant flowing in a suction pipe connecting the refrigerant evaporator and the refrigerant compressor. An air conditioner, comprising: