JP2017165142A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner which quickly performs heating.SOLUTION: An air conditioner 1 comprises: a heating cycle 4 which circulates a heating medium to a heater core 42 for heating blown air; an auxiliary heater 43 which heats the heating medium by an electric heater; a refrigeration cycle 2 which circulates a coolant discharged from a compressor 21 to a capacitor 22 for heating the heating medium; refrigeration cycle control means which causes the refrigeration cycle 2 to operate so that a temperature Tw of the heating medium becomes a target heating medium temperature; and auxiliary heater control means which causes the auxiliary heater 43 to operate so that the temperature Tw of the heating medium becomes the target heating medium temperature Two. The auxiliary heater control means is configured to stop operation of the auxiliary heater 43 when such a heat quantity that the temperature Tw of the heating medium reaches the target heating medium temperature Two only by heating by the refrigeration cycle 2, is obtained.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an air conditioner that adjusts the temperature of blown air.

  Patent Document 1 discloses that a heat medium heater that heats blown air blown into a vehicle interior, an electric heater that heats a heat medium circulating in the heat medium heater, and a refrigerant / heat medium heat exchanger that heats the heat medium. An air conditioner including a heat pump for circulation is disclosed.

  In the air conditioner, heating is performed at a high output by operating both the electric heater and the heat pump during heating when the outside air temperature is around 0 ° C. On the other hand, when the outside air temperature is 0 ° C. or higher, the operation of the electric heater is stopped, and only the heat pump is operated, so that heating is performed at a low output.

JP 2009-280020 A

  However, in the air conditioner of Patent Document 1, the electric heater operates only when the outside air temperature is low, so the electric heater may stop in a state where the heat medium is not sufficiently heated. Therefore, there is a possibility that heating cannot be performed rapidly.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide an air conditioner in which heating is performed rapidly.

  According to an aspect of the present invention, a heating cycle in which a heating medium is circulated through a heater core that heats blown air, an auxiliary heater that heats the heating medium with an electric heater, and a condenser that heats the heating medium are discharged from the compressor. A refrigeration cycle for circulating the refrigerant, a refrigeration cycle control means for operating the refrigeration cycle so that the temperature of the heat medium becomes the target heat medium temperature, and an auxiliary heater so that the temperature of the heat medium becomes the target heat medium temperature. An auxiliary heater control means for operating the auxiliary heater, and the auxiliary heater control means stops the operation of the auxiliary heater when the amount of heat at which the temperature of the heat medium reaches the target heat medium temperature can be obtained only by heating by the refrigeration cycle. An air conditioner characterized by this is provided.

  According to the above aspect, when the amount of heat reaching the target heat medium temperature is insufficient only by heating by the refrigeration cycle, the auxiliary heater and the refrigeration cycle are operated. When the amount of heat reaching the target heat medium temperature is sufficient only by heating by the refrigeration cycle as the temperature of the heat medium rises, the operation of the auxiliary heater is stopped and only the refrigeration cycle is operated. Thus, the air conditioner is rapidly heated.

FIG. 1 is a schematic configuration diagram illustrating an air conditioner according to an embodiment of the present invention. FIG. 2 is a block diagram of an electric circuit in the air conditioner. FIG. 3 is a chart showing target values used for controlling the air conditioner. FIG. 4 is a flowchart showing a control process for switching the operation mode in the air conditioner. FIG. 5 is a flowchart showing the control process of the auxiliary heater in the air conditioner. FIG. 6 is a flowchart showing control processing of the refrigeration cycle in the air conditioner. FIG. 7 is a time chart showing an example of control of the air conditioner.

  Hereinafter, an air conditioner 1 according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram showing an air conditioner 1.

  The air conditioner 1 controls a refrigeration cycle 2 in which a refrigerant circulates, a heating cycle 4 in which a heat medium circulates, an HVAC (Heating Ventilation and Air Conditioning) unit 5 through which air used for air conditioning passes, operation of valves, and the like. And a controller 10 (see FIG. 2) for cooling and heating. For the medium circulating in the refrigeration cycle 2, for example, a refrigerant made of HFC-134a is used. As the liquid medium circulating in the heating cycle 4, for example, a heat medium made of an antifreeze liquid (cooling water) is used. The liquid medium circulating in the heating cycle 4 is not limited to this, and other liquids such as oil may be used.

  The refrigeration cycle 2 includes a compressor 21 (compressor), a condenser 22, a first expansion valve 27, an outdoor heat exchanger 23, a liquid tank 24, an internal heat exchanger 60, a second expansion valve 28, It is comprised from the evaporator 25, the accumulator 26, and the refrigerant | coolant flow path 20 which connects these so that a refrigerant | coolant can circulate.

  The compressor 21 is driven by an electric motor (not shown), and compresses and discharges the refrigerant circulating in the refrigerant flow path 20.

  The condenser 22 is a heat exchanger that exchanges heat between the refrigerant circulating in the refrigeration cycle 2 and the heat medium circulating in the heating cycle 4.

  The outdoor heat exchanger 23 is installed in, for example, an engine room (a motor room in an electric vehicle) of a vehicle, and performs heat exchange between the refrigerant and the outside air. The outdoor heat exchanger 23 is arranged so that the vehicle running wind or the forced wind sent by the outdoor fan 32 passes through the heat exchange section. The outdoor fan 32 is driven by an electric motor (not shown).

  The liquid tank 24 temporarily stores the refrigerant that has passed through the outdoor heat exchanger 23 and condensed during cooling, and separates the refrigerant into a gaseous refrigerant and a liquid refrigerant.

  In the internal heat exchanger 60, heat exchange is performed between the refrigerant flowing in the refrigerant flow path 20 on the upstream side of the second expansion valve 28 and the downstream side of the evaporator 25.

  The evaporator 25 is installed in the HVAC unit 5. The evaporator 25 is a heat exchanger that cools the blown air by exchanging heat between the refrigerant and the blown air flowing through the HVAC unit 5.

  In the accumulator 26, the refrigerant flowing through the refrigerant flow path 20 is temporarily stored, and gas-liquid separation is performed into a gaseous refrigerant and a liquid refrigerant.

  A first expansion valve 27 is interposed in the refrigerant channel 20 between the condenser 22 and the outdoor heat exchanger 23. In the first expansion valve 27, the refrigerant condensed by the condenser 22 is expanded under reduced pressure. For the first expansion valve 27, for example, a fixed throttle (orifice) or a variable throttle (electromagnetic valve) is used.

  A second expansion valve 28 is interposed in the refrigerant flow path 20 between the internal heat exchanger 60 and the evaporator 25. In the second expansion valve 28, the refrigerant that has passed through the outdoor heat exchanger 23 and the internal heat exchanger 60 and condensed is decompressed and expanded. As the second expansion valve 28, a temperature type expansion valve whose opening degree is adjusted according to the temperature of the refrigerant that has passed through the evaporator 25 is used.

  The refrigerant flow path 20 is provided with a first on-off valve 29, a second on-off valve 30, and a third on-off valve 31. The first on-off valve 29, the second on-off valve 30, and the third on-off valve 31 are opened and closed by the controller 10 to switch the refrigerant flow. During heating, the first on-off valve 29 and the third on-off valve 31 are closed, and the second on-off valve 30 is opened. During cooling, the first on-off valve 29 and the third on-off valve 31 are opened, and the second on-off valve 30 is closed.

  The heating cycle 4 includes a water pump 41, a condenser 22, an auxiliary heater 43, a heater core 42, and a heat medium flow path 40 that connects them so that the heat medium can be circulated. In the heat medium passage 40, an auxiliary heater 43 is provided immediately downstream of the condenser 22, and a heater core 42 is provided immediately downstream of the auxiliary heater 43.

  The water pump 41 circulates the heat medium in the heat medium flow path 40 as indicated by solid arrows in FIG. The water pump 41 is driven by an electric motor (not shown).

  The heater core 42 is installed in the HVAC unit 5. The heater core 42 is a heat exchanger that heats the blown air by exchanging heat between the heat medium and the blown air flowing through the HVAC unit 5.

  The auxiliary heater 43 heats the heat medium circulating in the heat medium flow path 40 with electric power. The auxiliary heater 43 has an electric heater (not shown) therein. For example, a sheathed heater or a PTC (Positive Temperature Coefficient) heater is used as the electric heater.

  The HVAC unit 5 cools or heats blown air used for air conditioning. The HVAC unit 5 includes a blower 52 that blows air, an evaporator 25, a heater core 42, and an air mix door 53 that adjusts the amount of air passing through the heater core 42.

  The blower 52 is a blower that blows air into the HVAC unit 5. The blower 52 is driven by an electric motor (not shown).

  The air mix door 53 opens the heater core 42 side during heating, and closes the heater core 42 side during cooling. The amount of heat exchange performed between the blown air and the heat medium in the heater core 42 is adjusted by the opening degree of the air mix door 53.

  The controller 10 is switched to the cooling mode during cooling and is switched to the heating mode during heating to control the refrigeration cycle 2, the heating cycle 4, and the HVAC unit 5.

  Next, the operation of the air conditioner 1 in the heating mode and the cooling mode will be described.

<Heating mode>
In the refrigeration cycle 2, the refrigerant circulates through the refrigerant flow path 20 as indicated by the dashed arrows in FIG. 1. The refrigerant compressed to high temperature by the compressor 21 is sent to the condenser 22. In the condenser 22, the heat of the refrigerant that has become high temperature and pressure by the compressor 21 is transmitted to the heat medium. The low-temperature refrigerant that has passed through the condenser 22 is decompressed and expanded through the first expansion valve 27 to be further cooled, and is sent to the outdoor heat exchanger 23. In the outdoor heat exchanger 23, the refrigerant having a low temperature absorbs the heat of the outside air and is heated. The heated refrigerant is sent to the compressor 21 via the accumulator 26 and circulates. Thus, in the refrigeration cycle 2, a heat pump operation is performed in which the refrigerant absorbs heat of the outside air and dissipates heat to the heat medium circulating in the heating cycle 4.

  On the other hand, in the heating cycle 4, the heat medium circulates through the heat medium flow path 40 as indicated by solid line arrows in FIG. 1 and is heated by the condenser 22 and the auxiliary heater 43. The heated heat medium flows through the heater core 42 to heat the blown air.

  In the HVAC unit 5, the blown air heated through the heater core 42 is sent to the vehicle interior as shown by the white arrow in FIG. 1 to perform heating.

<Cooling mode>
In the cooling mode, the first on-off valve 29 and the third on-off valve 31 are opened, and the second on-off valve 30 is closed. As a result, the refrigerant that has been compressed by the compressor 21 to a high temperature is sent to the outdoor heat exchanger 23. In the outdoor heat exchanger 23, the heat of the refrigerant is radiated to the outside air. The refrigerant that has passed through the outdoor heat exchanger 23 is expanded under reduced pressure through the second expansion valve 28, and is further cooled to be sent to the evaporator 25. In the evaporator 25, the blown air is cooled by the low-temperature refrigerant. The refrigerant evaporated and gasified by passing through the evaporator 25 is heated by passing through the internal heat exchanger 60 and then sent to the compressor 21 via the accumulator 26 and circulated. Thus, in the refrigeration cycle 2, a heat pump operation is performed in which the circulating refrigerant absorbs the heat of the blown air sent into the passenger compartment and dissipates heat to the outside air.

  In the HVAC unit 5, the blown air cooled by passing through the evaporator 25 is sent into the passenger compartment, and cooling is performed.

  It is also possible to obtain dehumidified air by cooling the air with the evaporator 25 to condense and remove water vapor in the air and then reheating with the heater core 42 (dehumidifying heating mode).

  A discharge pressure sensor 11 is installed in the refrigerant flow path 20 on the discharge side of the compressor 21. The discharge pressure sensor 11 detects the pressure P of the refrigerant compressed by the compressor 21.

  An outdoor heat exchanger outlet temperature sensor 12 is installed in the refrigerant flow path 20 near the outlet of the outdoor heat exchanger 23. The outdoor heat exchanger outlet temperature sensor 12 detects the temperature of the refrigerant that has passed through the outdoor heat exchanger 23. The outdoor heat exchanger outlet temperature sensor 12 may be installed at the outlet of the outdoor heat exchanger 23.

  An evaporator temperature sensor 13 is installed on the downstream side of the evaporator 25 in the HVAC unit 5. The evaporator temperature sensor 13 detects the temperature T of the blown air that has passed through the evaporator 25. Note that the evaporator temperature sensor 13 may be installed inside the evaporator 25.

  The water temperature sensor 14 is installed in the heat medium flow path 40 near the outlet of the auxiliary heater 43 and detects the temperature Tw of the heat medium that has passed through the auxiliary heater 43.

  FIG. 2 is a block diagram illustrating a configuration of an electric circuit according to the controller 10. The controller 10 is configured by a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and by the CPU reading out a program stored in the ROM, the air conditioner 1 performs various functions. Let Signals from various sensors 11 to 17 and the temperature setting device 18 are input to the controller 10. Based on the input signal, the controller 10 includes an auxiliary heater 43, a compressor 21, a water pump 41, a blower 52, a first on-off valve 29, a second on-off valve 30, a third on-off valve 31, and an air mix door. Each operation of 53 is controlled.

  In the heating mode, the controller 10 feedback-controls the output of the auxiliary heater 43 so that the temperature Tw of the heat medium circulating in the heating cycle 4 approaches the target heat medium temperature Two (see FIG. 5), and the heat medium The output of the refrigeration cycle 2 (compressor 21) is feedback controlled so that the temperature Tw approaches the target heat medium temperature Two (see FIG. 6).

  As shown in the chart of FIG. 3, in the controller 10, as a target value used for output control of the auxiliary heater 43 and the refrigeration cycle 2, a calculation target blow temperature Ttarget, a control target blow temperature To, a target heat medium A temperature Two and a target refrigerant pressure Po are set.

  The calculated target blowing temperature Ttarget is a target value of the blowing temperature T of air blown from the HVAC unit 5 into the vehicle interior. The target blowing temperature Ttarget is a temperature setting device that sets the temperature in the vehicle interior in accordance with the outside air temperature detected by the outside air temperature sensor 15, the room temperature detected by the room temperature sensor 16, and the amount of solar radiation detected by the solar radiation sensor 17. 18 is set to maintain the temperature set by.

  The target blowout temperature To in control is a value in which a predetermined upper limit value (for example, 60 ° C.) is set to the target blowout temperature Ttarget. The upper limit 60 ° C. is set so that the refrigerant compression ratio by the compressor 21 does not exceed the upper limit, as will be described later.

The target heat medium temperature Two is a target value of the temperature of the heat medium circulating in the heating cycle 4. The target heat medium temperature Two is calculated according to the target blowing temperature To based on the following mathematical formula (1).
Two = To + Cw (1)

  However, Cw is a constant and is set to 2 ° C., for example. Since the upper limit value of the target blowing temperature To is set to 60 ° C., the upper limit value of the target heat medium temperature Two is set to 62 ° C.

The target refrigerant pressure Po is a target value of the pressure P of the refrigerant discharged from the compressor 21. The target refrigerant pressure Po is a pressure at which the saturation value of the refrigerant flowing into the capacitor 22 becomes the target value Trefo. The target refrigerant temperature Trefo is calculated according to the target heat medium temperature Two (target blowing temperature To) based on the following mathematical formula (2).
Tref0 = Two + Cref (2)

  However, Cref is a constant and is set to 5 ° C., for example. Since the target heat medium temperature Two is set to 62 ° C., the upper limit value of the target value Trefo for the target refrigerant temperature (target refrigerant pressure) is set to 67 ° C.

  In addition, not only the structure which feedback-controls the driving | operation of the refrigerating cycle 2 according to the detected value P of the discharge pressure sensor 11, but the discharge temperature sensor (illustration omitted) which detects the temperature of the refrigerant | coolant discharged from the compressor 21 is provided, It is good also as a structure which feedback-controls the driving | operation of the refrigerating cycle 2 according to the detected value of a discharge temperature sensor.

  By the way, at the time of the driving | running which the refrigerant | coolant temperature Tref rises exceeding predetermined value (for example, 67 degreeC), since the compression ratio of the refrigerant | coolant by the compressor 21 exceeds an upper limit and becomes high too much, efficiency of the refrigerating cycle 2 (heating capacity with respect to input) Ratio) is lower than the efficiency of the auxiliary heater 43.

  Therefore, in the controller 10, the upper limit value of the target value Tref of the refrigerant temperature Tref (refrigerant pressure) is set to 67 ° C. so that the refrigerant compression ratio by the compressor 21 does not exceed the upper limit value. In relation to the target value Trefo, an upper limit value (60 ° C.) of the target blowing temperature Ttarget and an upper limit value (62 ° C.) of the target heat medium temperature Two are set. Thereby, the air conditioner 1 is avoided from being operated in a low efficiency state in which the refrigerant compression ratio by the compressor 21 becomes excessively high.

  Next, a routine for switching the operation mode of the air conditioner 1 executed by the controller 10 will be described with reference to the flowchart of FIG. This control routine starts when an ignition switch (not shown) of the vehicle is turned on and power is supplied to the controller 10, and is executed at predetermined intervals.

  First, in step S101, it is determined whether or not an air conditioning switch (not shown) for operating the air conditioner 1 is turned on. If it is determined that the air conditioning switch is off, the process proceeds to step S102 and the operation of the auxiliary heater 43 is prohibited. Then, it progresses to step S103 and the driving | operation of the refrigerating cycle 2 is prohibited. Then, it progresses to step S104 and switches to air-conditioning OFF mode. Thus, the state where the operation of the air conditioner 1 is stopped is maintained.

  On the other hand, if it is determined in step S101 that the air conditioning switch is on, the process proceeds to step S105, and the calculated target blowing temperature Ttarget is detected by the outside air temperature sensor 15, the indoor temperature sensor 16, and the solar radiation sensor 17. Calculate according to

  Subsequently, the process proceeds to steps S106 to S108, and a target blowout temperature To for control is obtained based on the target blowout temperature Ttarget. If it is determined in step S106 that the target blowing temperature Ttarget exceeds the upper limit 60 ° C., the process proceeds to step S108, and the target blowing temperature To is set to the upper limit 60 ° C. On the other hand, when it is determined that the target blowing temperature Ttarget is the upper limit value of 60 ° C. or less, the process proceeds to step S107, and the target blowing temperature To is set to Ttarget.

  Then, it progresses to step S109 and it determines whether it is heating mode or cooling mode according to setting conditions. If it is determined that the cooling mode is selected, the process proceeds to step S110, and the operation of the air conditioner 1 is switched to the cooling mode. In the cooling mode, the refrigeration cycle 2 is operated by another control routine (not shown), and the passenger compartment is cooled.

  On the other hand, when it determines with heating mode in step S109, it progresses to step S111 and after and the process of heating mode is performed.

  In the heating mode, first, the process proceeds to step S111, and it is determined whether or not the heating is started to be switched from the air conditioning OFF mode in which the operation of the air conditioning apparatus 1 is stopped to the air conditioning ON mode in which the air conditioning apparatus 1 is operated. Here, when it is determined that the heating is started, the process proceeds to step S112, and the operation of the auxiliary heater 43 is permitted. Then, it progresses to step S113 and the driving | operation of the refrigerating cycle 2 is permitted.

  On the other hand, if it is determined in step S111 that the heating has already started, the process proceeds to step S114, where it is determined that the operation of the auxiliary heater 43 is permitted, and the process proceeds to step S115. The operation of the auxiliary heater 43 is controlled (see FIG. 5).

  Subsequently, the process proceeds to step S116, it is determined that the operation of the compressor 21 is permitted, and the process proceeds to step S117 to control the operation of the refrigeration cycle 2 (see FIG. 6).

  When the control routine is executed, the operation mode of the air conditioner 1 is switched according to the operating conditions.

  Next, a routine for controlling the output of the auxiliary heater 43 executed by the controller 10 will be described with reference to the flowchart of FIG. This control routine corresponds to auxiliary heater control means for operating the auxiliary heater 43 so that the temperature Tw of the heat medium becomes the target heat medium temperature Two. This control routine is executed every predetermined period.

  First, in step S201, the target heating medium temperature Two is calculated from the control target blowing temperature To based on the mathematical formula (1) (see FIG. 3).

Then, it progresses to step S202 and calculates difference (DELTA) T of target heat-medium temperature Two and heat-medium temperature Tw based on following Numerical formula (3).
ΔT = Two−Tw (3)

Subsequently, the process proceeds to step S203, and a calculation target output Dtarget is calculated based on the following mathematical formula (4).
Dtarget = Kpw * ΔT + Kiw * ΔT + EEw (4)

  Here, Kpw is a proportional coefficient, Kiw is an integral coefficient, and EEw is an integral integral term up to the previous time.

Subsequently, the process proceeds to step S204, where the current integral integral term EEw is overwritten on the previous integral integral term based on the following equation (5).
EEw = Kiw * ΔT + EEw (5)

  By executing the control routine, the output of the auxiliary heater 43 is feedback-controlled so that the temperature Tw of the heat medium gradually approaches the target heat medium temperature Two.

  Next, a routine for controlling the output of the refrigeration cycle 2 (compressor 21) executed by the controller 10 will be described with reference to the flowchart of FIG. This control routine corresponds to a refrigeration cycle control means for operating the refrigeration cycle 2 so that the temperature Tw of the heat medium becomes the target heat medium temperature Two. This control routine is executed every predetermined period.

  First, in step S301, the target heat medium temperature Trefo is calculated from the control target blowing temperature To based on the mathematical formula (2) (see FIG. 3).

  Subsequently, the process proceeds to step S302, and the target refrigerant pressure Po is calculated from the target refrigerant temperature Trefo.

Subsequently, the process proceeds to step S303, and a difference ΔT between the target refrigerant pressure Po and the discharge refrigerant pressure Pd detected by the discharge pressure sensor 11 is calculated based on the following formula (6).
ΔT = Po−Pd (6)

Subsequently, the process proceeds to step S304, where the calculated target rotational speed Rtarget is calculated based on the following mathematical formula (7).
Rtarget = Kpp * ΔP + Kip * ΔP + EEp (7)

  However, Kpp is a proportional coefficient, Kip is an integral coefficient, and EEp is an integral integral term up to the previous time.

Subsequently, the process proceeds to step S304, in which the current integral integral term EEw is overwritten on the previous integral integral term based on the following formula (8).
EEp = Kip * ΔP + EEp (8)

  By executing the control routine, the rotation speed (output) of the compressor 21 is controlled so that the temperature Tw of the heat medium approaches the target heat medium temperature Two.

  Next, an operation performed when the air conditioner 1 starts operation at a low outside air temperature will be described using the time chart of FIG.

  At time t0 in the time chart, the operation of the air conditioner 1 is started in the heating mode. At the start of this operation, since both the blown air blowing temperature T and the heat medium temperature Tw are low, a high heating capacity is required. Corresponding to this situation, the calculation target blowing temperature Ttarget is set to be higher than the upper limit 60 ° C., but the control target blowing temperature To becomes the upper limit 60 ° C., and the target The heating medium temperature Two becomes an upper limit 62 ° C. (see FIG. 3).

  In the operation after the start of operation after time t0, since the temperature Tw of the heat medium is lower than the target value Two and the refrigerant temperature Tref is lower than the target value Trefo, the high output mode in which the auxiliary heater 43 and the refrigeration cycle 2 are operated. Driving is performed. In this high output mode, the heat medium circulating in the heating cycle 4 is heated by both the auxiliary heater 43 and the refrigeration cycle 2, whereby the amount of heat given to the heat medium is increased and heating is performed rapidly.

  In the high output mode, the target blowing temperature To and the target heating medium temperature Two gradually decrease as the heating medium temperature Tw increases beyond a predetermined value. At this time, the output of the auxiliary heater 43 decreases and the output share of the refrigeration cycle 2 gradually increases.

  When the heat medium temperature Tw reaches the target heat medium temperature Two at time t1, the auxiliary heater 43 is stopped and switched to the high efficiency mode in which only the refrigeration cycle 2 is operated. In this high efficiency mode, only the refrigeration cycle 2 having higher efficiency than the auxiliary heater 43 is operated, so that heating is performed while suppressing power consumption.

  In the high efficiency mode, the heating medium temperature Tw reaches the upper limit value (62 ° C.) at time t2, but thereafter the operation of the refrigeration cycle 2 is fed back so that the heating medium temperature Tw does not exceed the upper limit value (62 ° C.). Be controlled.

  As described above, in the time chart of FIG. 7, the operation in the high output mode is performed between time t0 and t1, and the operation in the high efficiency mode is performed after time t1.

  According to the air conditioner 1 according to the above-described embodiment, the following effects can be obtained.

  The air conditioner 1 discharges from the compressor 21 to a heating cycle 4 that circulates a heating medium in a heater core 42 that heats blown air, an auxiliary heater 43 that heats the heating medium by an electric heater, and a capacitor 22 that heats the heating medium. The refrigeration cycle 2 for circulating the refrigerant to be circulated and the controller 10 for controlling the operation of the refrigeration cycle 2 and the auxiliary heater 43 are provided. The controller 10 includes a refrigeration cycle control means for operating the refrigeration cycle 2 so that the temperature Tw of the heat medium becomes the target heat medium temperature Two, and auxiliary heating so that the temperature Tw of the heat medium becomes the target heat medium temperature Two. Auxiliary heater control means for operating the heater 43. Then, the auxiliary heater control means is configured to stop the operation of the auxiliary heater 43 when the amount of heat at which the temperature Tw of the heat medium reaches the target heat medium temperature Two is obtained only by heating by the refrigeration cycle 2.

  Based on the above configuration, according to the air conditioner 1, in the process of increasing the temperature Tw of the heat medium, when the temperature Tw of the heat medium is low, the temperature Tw of the heat medium is within a predetermined time only by heating by the refrigeration cycle 2. When the amount of heat necessary to reach the target heat medium temperature Two is insufficient, the auxiliary heater 43 and the refrigeration cycle 2 are operated. Thereby, the amount of heat given to the heat medium is increased, and heating is performed rapidly. If the heat medium temperature Tw rises and the amount of heat necessary for the heat medium temperature Tw to reach the target heat medium temperature Two within a predetermined time is sufficient only by heating by the refrigeration cycle 2, auxiliary heating is performed. The operation of the vessel 43 is stopped and only the refrigeration cycle 2 is operated, so that power consumption is suppressed. Thus, the air conditioner 1 is efficiently heated after being heated rapidly.

  Further, the controller 10 calculates a target heat medium temperature calculating means for calculating the target heat medium temperature Two according to the target blowing temperature To of the blown air, and a target refrigerant temperature for calculating the target refrigerant temperature Trefo according to the target heat medium temperature Two. Calculating means. The refrigeration cycle control means controls the operation of the refrigeration cycle 2 so that the refrigerant temperature Tref (refrigerant pressure) discharged from the compressor 21 approaches the target refrigerant temperature Trefo, and the auxiliary heater control means The operation of the auxiliary heater 43 is controlled so that the medium temperature Tw approaches the target heat medium temperature Two.

  Based on the above configuration, the air conditioner 1 operates according to the operating condition by operating the refrigeration cycle 2 according to the refrigerant temperature Tref (refrigerant pressure) and operating the auxiliary heater 43 according to the heat medium temperature Tw. Depending on the situation, heating is performed efficiently.

  In addition, the target heat medium temperature Two is set to a value lower than the target refrigerant temperature Trefo.

  Based on the above configuration, when the temperature T of the blown air approaches the target blowout temperature Ttarget in the high output mode, the refrigerant temperature is increased even after the temperature Tw of the heat medium reaches the target heat medium temperature Two and the auxiliary heater stops. The temperature Tref does not reach the target refrigerant temperature Trefo, and the mode is switched to the high efficiency mode in which only the refrigeration cycle 2 is operated.

  The upper limit 62 ° C. of the target heat medium temperature Two is set so that the refrigerant compression ratio by the compressor 21 does not exceed the upper limit.

  Based on the above configuration, the refrigeration cycle 2 is operated so that the compression ratio of the refrigerant by the compressor 21 does not exceed the upper limit value. Thus, the air conditioner 1 is prevented from entering a low efficiency state in which the refrigerant compression ratio by the compressor 21 becomes excessively high and the efficiency of the refrigeration cycle 2 is reduced, and is operated with low power consumption.

  Further, the controller 10 is switched to the high output mode in which the auxiliary heater 43 and the refrigeration cycle 2 are operated in the process of increasing the temperature Tw of the heat medium, and then the operation of the auxiliary heater 43 is stopped and the refrigeration cycle. The high-efficiency mode in which only 2 is operated is switched.

  Based on the above configuration, according to the air conditioner 1, heating is rapidly performed in the high output mode in the early heating stage where rapid heating is required. Thereby, after the temperature Tw of the heat medium has sufficiently increased, the mode is switched to the high efficiency mode. Thereby, the power consumption at the time of the normal heating after the rapid heating is completed is suppressed.

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

  The present invention is suitable as an air conditioner mounted on a vehicle, but can also be applied to an air conditioner used other than a vehicle.

DESCRIPTION OF SYMBOLS 1 Air conditioner 2 Refrigeration cycle 4 Heating cycle 10 Controller 21 Compressor 22 Condenser 42 Heater core 43 Auxiliary heater

Claims (5)

An air conditioner,
A heating cycle in which a heat medium is circulated in a heater core that heats blown air;
An auxiliary heater that heats the heating medium with an electric heater;
A refrigeration cycle in which a refrigerant discharged from the compressor is circulated through a condenser that heats the heat medium;
Refrigeration cycle control means for operating the refrigeration cycle so that the temperature of the heat medium becomes a target heat medium temperature;
An auxiliary heater control means for operating the auxiliary heater so that the temperature of the heat medium becomes the target heat medium temperature,
The auxiliary heater control means stops the operation of the auxiliary heater when the amount of heat at which the temperature of the heat medium reaches the target heat medium temperature is obtained only by heating by the refrigeration cycle. The air conditioner according to claim 1,
Target heat medium temperature calculating means for calculating the target heat medium temperature according to the target blowing temperature of the blown air set according to the operating condition;
A target refrigerant temperature calculation means for calculating a target refrigerant temperature according to the target heat medium temperature,
The refrigeration cycle control means controls the operation of the refrigeration cycle so that the temperature of the refrigerant discharged from the compressor approaches the target refrigerant temperature,
The auxiliary heater control means controls the operation of the auxiliary heater so that the temperature of the heating medium approaches the target heating medium temperature. The air conditioner according to claim 2,
The target heat medium temperature is set to a value lower than the target refrigerant temperature. The air conditioner according to claim 2 or 3,
The upper limit value of the target heat medium temperature is set so that the refrigerant compression ratio by the compressor does not exceed the upper limit value. The air conditioner according to any one of claims 1 to 4,
In the process of increasing the temperature of the heating medium, after the auxiliary heater and the refrigeration cycle are switched to the high output mode in which the operation is performed, the operation of the auxiliary heater is stopped and only the refrigeration cycle is operated. An air conditioner that can be switched to an efficiency mode.