JP6348293B2 - Air conditioner for vehicles - Google Patents

Description

  The present invention relates to a vehicle air conditioner, and more particularly to the technical field of hot water preheating for hot water heating.

JP 2012-13336 A JP 2011-64395 A JP 2010-164199 A

Regarding the heating technology, heat pump systems and hot water heating systems are known.
Patent Document 1 discloses a technique for warming hot water by a combination of a unit for discharging hot water heated by a heat pump system and an auxiliary heat source device.
Patent Document 2 describes a heat pump type hot water heating apparatus that can suppress a decrease in the temperature of hot water sent to a heating terminal even if it is used for heat exchange of hot water that uses hot water in a hot water storage tank for hot water supply.
Patent Document 3 discloses a heat pump type hot water heater.

By the way, when using a warm water heating system, it is necessary to warm an aqueous medium to a temperature at which warm air can be blown. For this reason, in the hot water heating system for vehicles, it is preferable to preliminarily warm the aqueous medium in the hot water storage tank so that the occupant can get warm air blown immediately after getting on.
An object of the present invention is to enable such preheating of an aqueous medium to be carried out in an energy efficient manner.

1stly, the vehicle air conditioner which concerns on this invention stores the aqueous medium heated with the electric water heater in the hot water storage tank, circulates the aqueous medium of a hot water storage tank, and uses the heat exchanger provided in the circulation path. A hot water heating unit for warmly blowing air into the passenger compartment, a heat pump system unit configured to be able to heat at least the aqueous medium of the hot water storage tank, a power supply unit including a battery, and an aqueous medium in the hot water storage tank during charging of the battery when performing preheating, the heating by the electric water heater, the heating by the heat pump system unit, e Bei and a control unit for executing selected according to outside air temperature, the control unit, the preheating In accordance with a change in the outside air temperature after the start, switching control between heating by the electric water heater and heating by the heat pump system unit is performed .
In electric vehicles, hybrid vehicles, etc., it is particularly necessary to reduce power consumption and increase efficiency. This is considered for preheating of hot water heating. In hot water heating, power consumption for heating an aqueous medium to a predetermined temperature required for warm air blowing is large. Here, from the viewpoint of COP (Coefficient Of Performance), the heat pump system has a relatively high COP, but the efficiency deteriorates when the outside air temperature is around 0 ° C. or less. On the other hand, heating of the aqueous medium by the electric heater in the hot water heating system has a relatively low COP, but is not significantly affected by the outside air temperature. Therefore, heating by the electric water heater and heating by the heat pump system unit are selectively executed according to the outside air temperature.
This also corresponds to the case where the outside air temperature changes greatly during the preheating.

2ndly, in the vehicle air conditioner which concerns on above-mentioned this invention, it is desirable that the warm air ventilation to a vehicle interior is not performed during execution of the said preheating.
The water medium in the hot water storage tank is heated to the end, and the situation in which heat escapes from the passenger compartment to the outside of the vehicle is not created by not heating the passenger compartment.

Third, the air conditioning system for vehicles according to the present invention described above, the control unit monitors the time, it is desirable to control so that the preheating is started in response to a set time.
Accordingly, for example, preheating can be performed at a timing convenient for the occupant as timer control.

Fourth, the air conditioning system for vehicles according to the present invention described above, the control unit, the water temperature of the hot water storage tank monitoring, water temperature the preheated in response to is equal to or less than a predetermined pre-heating start determination temperature It is desirable to control so that is started.
Thereby, electric power can be used efficiently without performing unnecessary preheating.

  ADVANTAGE OF THE INVENTION According to this invention, the preheating with sufficient energy efficiency is attained by selectively performing the heating by the electric water heater of a warm water heating part, and the heating by a heat pump system part according to external temperature.

It is a block diagram of the vehicle air conditioner of an embodiment of the invention. It is a flowchart of the preheating process of 1st Embodiment. It is a flowchart of the preheating process of 2nd Embodiment. It is a flowchart of preheating start judgment processing of an embodiment.

<1. Configuration of vehicle air conditioner>
FIG. 1 shows the configuration of a vehicle air conditioner according to an embodiment of the present invention. The vehicle air conditioner of the present embodiment is mounted on an electric vehicle or a hybrid vehicle.
This vehicle air conditioner employs a configuration in which the heat pump section 10 and the hot water heating section 20 are combined. FIG. 1 shows only the main part.

  The hot water heating section 20 is provided with a heater unit 21, valves 22 and 23, an electric water heater 24, a chiller / hot water storage tank (hereinafter referred to as “hot water storage tank”) 25, a circulation pump 26, and a water temperature sensor 27. The circulation pump 26 causes an aqueous medium such as antifreeze liquid to flow through the circulation path 30 including the hot water storage tank 25, the heater unit 21, and the electric water heater 24.

The heater unit 21 warms air from a blower (not shown) with warm water flowing in the circulation path and blows it into the passenger compartment.
The aqueous medium circulation path 30 may include a bypass path 30 </ b> B that bypasses the heater unit 21 by the valves 22 and 23. When the bypass path 30B is used, warm air blowing to the vehicle interior by the heater unit 21 is not performed.
The electric water heater 24 heats the aqueous medium flowing through the circulation path 30 with an electric heater.
The aqueous medium heated by the electric heater is guided to the hot water storage tank 25.
The water temperature sensor 27 detects the temperature of the aqueous medium in the hot water storage tank 25.

The heat pump section 10 includes an external heat exchanger 11, an accumulator 12, a compressor 13, a tank heat exchanger 14, an expansion valve 15, and a valve 16.
The heat pump section 10 constitutes the refrigerant circulation path 40 at the above-described parts, and the refrigerant absorbed by the external heat exchanger 11 is heated by the compressor 13 and supplied to the tank heat exchanger 14. The tank heat exchanger 14 heats the aqueous medium in the hot water storage tank 25.

The power supply unit 3 includes a battery 3a and peripheral circuits (such as a relay switch, a DC / DC converter, an inverter, and a charging circuit) of the battery 3a, and supplies power to the motor and electrical components of the vehicle. As shown in the figure, the power supply unit 3 supplies driving power to the compressor 13 of the heat pump section 10 via the switch 4a and switches driving power to the electric water heater 24 of the hot water heating section 20 as illustrated. Supplied via 4b.
The battery 3a is charged by connecting the external power supply 100 to the charging circuit of the power supply unit 3. The external power supply 100 is, for example, a household commercial AC power supply or a charge-dedicated power supply.

The control unit 1 is formed by a microcomputer or the like provided in the vehicle body as an ECU (electronic control unit), for example, and controls the vehicle air conditioner in FIG. The control unit 1 performs drive control of the heat pump section 10, control of the valve 16, drive control of the circulating pump 26 in the hot water heating section 20, and switching control of the valves 22 and 23. Moreover, the control part 1 controls the drive electric power supply of the compressor 13 and the electric water heater 24 by ON / OFF control of switch 4a, 4b.
The control unit 1 can monitor the outside air temperature based on the outside air temperature information Tmp from the temperature sensor 2 that detects the outside air temperature. Further, the temperature of the aqueous medium in the hot water storage tank 25 can be monitored by the water temperature information TW from the water temperature sensor 27.
The clock unit 5 counts the current date and time and supplies time information to the control unit 1.

  The above configuration of FIG. 1 is an example, and various other configurations as a vehicle air conditioner are conceivable. However, at least the vehicle air conditioner according to the embodiment of the present invention is provided in the circulation path 30 by storing the water heated by the electric water heater 24 in the hot water storage tank 25 and circulating the aqueous medium in the hot water storage tank 25. The heater unit 21 (heat exchanger) is used to provide a hot water heating section 20 that blows warm air into the passenger compartment and a heat pump section 10 that is configured to heat at least the aqueous medium of the hot water storage tank 25. That is, as a means for heating the aqueous medium in the hot water storage tank 25, the electric water heater 24 in the hot water heating section 20 and the heat pump system are provided.

<2. Preheating treatment of first embodiment>
In the vehicle air conditioner of the present embodiment configured as described above, the aqueous medium is preheated using the electric power during charging while the battery 3a is being charged. By setting the temperature of the aqueous medium to a predetermined temperature, for example, about 60 ° C. to 70 ° C. by preheating, when the user gets on the car and turns on the heating, the hot air can be immediately blown into the vehicle interior. Because.

FIG. 2 shows a preheating process executed by the control unit 1 as the first embodiment.
When preheating is started, the control unit 1 first sets a path for preheating in step S101. Specifically, the valves 22 and 23 are controlled to enable the bypass path 30B. That is, the circulation path 30 including the bypass path 30B that does not pass through the heater unit 21 is formed.
In step S102, the control unit 1 checks the outside air temperature information Tmp from the temperature sensor 2. In step S103, it is determined whether or not the outside air temperature information Tmp is equal to or higher than the threshold temperature th1. The threshold temperature th1 is set as a temperature at which the COP of the heat pump system decreases, and is set to 0 ° C., for example.

When the outside air temperature information Tmp is equal to or higher than the threshold temperature th1, the control unit 1 proceeds from step S103 to S104, and starts heating the aqueous medium by the heat pump section 10. That is, the driving of the heat pump section 10 is started, the switch 4a is turned on, and driving power is supplied to the compressor 13. In this case, circulation of the aqueous medium by the circulation path 30 by the circulation pump 26 may be executed, or the circulation may be stopped.
On the other hand, when the outside air temperature information Tmp is lower than the threshold temperature th1, the control unit 1 proceeds from step S103 to S105, and starts the heating of the aqueous medium by the hot water heating section 20. That is, the circulation of the aqueous medium is started by the circulation pump 26, and the switch 4b is turned on to supply the electric water heater 24 with driving power for heating. The circulation of the aqueous medium passes through the bypass path 30B.

  As described above, after the heating of the aqueous medium in the hot water storage tank 25 is started in step S104 or S105, the control unit 1 monitors the water temperature information TW from the water temperature sensor 27 in step S106. Then, heating is continued until the temperature of the aqueous medium reaches a target temperature (for example, 70 ° C.). When the temperature reaches the target temperature, the process proceeds to step S107 to end the heating. That is, the driving of the heat pump section 10 or the hot water heating section 20 is stopped, and the power supply for heating is also stopped by turning off the switch 4a or 4b that has been turned on.

  When the preheating of the aqueous medium is executed by the process of FIG. 2 described above, the heating by the electric water heater 24 and the heating by the heat pump section 10 are selected and executed according to the outside air temperature.

<3. Preheating treatment of second embodiment>
FIG. 3 shows a preheating process executed by the control unit 1 as the second embodiment. Steps S101 to S105 are the same as those in FIG. That is, heating by the heat pump section 10 and heating by the electric water heater 24 are selected according to the outside air temperature information Tmp, and heating of the aqueous medium is started.

In the second embodiment, it is assumed that the controller 1 monitors the outside air temperature even after the start of heating.
After the heating by the heat pump section 10 is started in step S104, the controller 1 monitors whether or not the aqueous medium has reached the target temperature in step S110, and the outside air temperature information Tmp is determined from the switching temperature th2 in step S111. Monitor whether it is low.
If Tmp <th2, the control unit 1 proceeds to step S112 and switches to heating by the electric water heater 24. In other words, the switch 4a is turned off, the switch 4b is turned on, the drive of the heat pump section 10 is stopped, and the hot water heating section 20 is started to be driven (start of driving of the circulation pump 26). Then, the process proceeds to a loop of steps S120 and S121.
As a result, when the outside air temperature decreases during the preheating, and the energy efficiency of the heating by the heat pump section 10 decreases, the heating is switched to the heating by the hot water heating section 20.

Further, after the heating by the electric water heater 24 is started in step S105, the control unit 1 monitors whether or not the aqueous medium has reached the target temperature in step S120, and the outside air temperature information Tmp is switched to the switching temperature in step S121. It is monitored whether or not it becomes higher than th3.
If Tmp> th3, the control unit 1 proceeds to step S122 and switches to heating by the heat pump section 10. That is, the switch 4b is turned off, the switch 4a is turned on, and the drive start of the heat pump section 10 is controlled. The driving of the circulation pump 26 in the hot water heating section 20 may be continued or stopped. Then, the process proceeds to a loop of steps S110 and S111.
As a result, when the outside air temperature rises during the preheating, and the energy efficiency of the heating by the heat pump section 10 becomes good, the heating pump section 10 is switched to the heating.

  Thereafter, when it is detected in either step S110 or S120 that the temperature of the aqueous medium has reached the target temperature (for example, 70 ° C.), the control unit 1 proceeds to step S107 and ends the heating. That is, the driving of the heat pump section 10 or the hot water heating section 20 is stopped, and the power supply for heating is also stopped by turning off the switch 4a or 4b that has been turned on.

When the preheating of the aqueous medium is executed by the process of FIG. 3 described above, the heating by the electric water heater 24 and the heating by the heat pump section 10 are selected and executed according to the outside air temperature, and the preheating is performed. Even when the outside air temperature fluctuates, switching between the two heating methods is executed.
Note that the switching temperatures th2 and th3 may be the same as the threshold temperature th1, but for example, by setting th2 <th1 <th3, it is possible to avoid switching between the two heating methods too frequently. For example, if th1 = th2 = th3, when the outside air temperature at the start of the preheating is close to the threshold temperature th1, the heating method is frequently switched with a slight change in air temperature, which may adversely deteriorate the energy efficiency. Conceivable. Therefore, by setting th2 <th1 <th3, it is preferable to perform switching when there is a significant temperature drop or temperature rise.

<4. Preheating start judgment>
Next, a process for starting the preheating process of the first and second embodiments will be described.
In the present embodiment, it is assumed that the preliminary heating is performed when the engine (motor) of the vehicle is stopped and the battery 3a is charged. However, it is considered that it is wasteful to always perform preheating during charging. Therefore, for example, it is desirable to perform the preheating start determination by the processing as shown in FIGS.

First, the process of FIG. 4A will be described. While the vehicle engine (motor) is stopped, the external power supply 100 is connected, and the battery 3a is being charged, the control unit 1 proceeds from step S201 to S202, and checks the water temperature information TW by the water temperature sensor 27. To do. In step S203, it is determined whether or not the water temperature information TW is equal to or lower than the preheating start determination temperature th4. If TW ≦ th4, the process proceeds to step S204 to start the preheating process in FIG.
On the other hand, even during charging, if TW> th4, preheating is not started.
By such treatment, it is avoided that unnecessary preheating is started when the water temperature of the aqueous medium is not lowered. The preheating start determination temperature th4 may be, for example, about 50 ° C., or may be set lower, for example, 30 ° C., 10 ° C., or the like.

Next, in the process of FIG. 4B, during a period when the engine (motor) of the vehicle is stopped and the external power source 100 is connected and the battery 3a is charged, the control unit 1 proceeds from step S210 to step S211. The time information from the clock unit 5 is checked. In step S212, it is determined whether or not the current time has reached the time set as the preheating start time.
When it is the start time, the control unit 1 checks the water temperature information TW by the water temperature sensor 27 in step S213. In step S214, it is determined whether or not the water temperature information TW is equal to or lower than the preheating start determination temperature th4. If TW ≦ th4, the process proceeds to step S215 to start the preheating process of FIG. 2 or FIG.
On the other hand, even if the battery is being charged, preheating is not started if TW> th4 even when the start time has not been reached or when the start time has been reached. Such processing prevents unnecessary preheating from being performed.

Note that the start time determined in step S212 may be a time according to the timer setting of the user of the vehicle.
For example, when the user gets on at 7 am every day, a boarding time of 7:00 is input in advance. Based on this timer setting, the control unit sets x hours before 7:00 as the start time. The x time is usually a time required for preheating. Alternatively, the x time may be adjusted by sequentially referring to the water temperature information TW and the outside air temperature information Tmp. That is, when the user gets on at 7:00, the temperature of the aqueous medium only needs to reach the target temperature (for example, about 60 to 70 ° C.), so that the preheating is started in time for the timer set time. To do.
Alternatively, the user may directly set the preheating start time with a timer.
Preliminary heating with the least waste is possible based on user settings.

  It is also conceivable to set the start time by learning processing. For example, the control unit 1 stores the time when the ignition is turned on every time, and estimates the time when the user gets on by statistical processing. When an estimated boarding time with a certain degree of accuracy is obtained, a preheating start time is set in time. Accordingly, appropriate preheating is performed without requiring the user to take time.

<5. Summary and Modification>
As described above, the vehicle air conditioner according to the present embodiment, as a method for heating the aqueous medium of the hot water heating section 20, uses the heat pump section 10 and heating using the electric water heater 24 of the hot water heating section 20. It can be performed. Then, as shown in the first and second embodiments, the controller 1 performs heating by the electric water heater 25 when preheating the aqueous medium in the hot water storage tank 25 during charging of the battery, Heating by the heat pump section 10 is selected and executed according to the outside air temperature information Tmp.
The heat pump system has a relatively high COP, but the efficiency deteriorates when the outside air temperature is below about 0 ° C. On the other hand, heating of the aqueous medium by the electric heater in the hot water heating system has a relatively low COP, but is not significantly affected by the outside air temperature. Therefore, when the outside air temperature is lower than the threshold temperature th1, preheating by an electric water heater is executed, and when the outside air temperature is equal to or higher than the threshold temperature th1, preheating by the heat pump system unit is executed. By doing so, preheating with high energy efficiency can be realized. In particular, in an electric vehicle, a hybrid vehicle, etc., it is important to make power consumption efficient, and it is suitable as an air conditioner for vehicles.
Further, in an air conditioner as a hot water heating system, electric power is most used to heat an aqueous medium to a temperature at which warm air can be blown. Making this heating efficient is most desirable in terms of providing a comfortable driving environment and reducing power consumption.

  In the embodiment, during the preheating, the bypass path 30B is included in the circulation path 30 and the warm air blowing into the vehicle interior is not performed. It is assumed that the aqueous medium in the hot water storage tank 25 is heated to the end, and heat is not released from the passenger compartment to the outside of the vehicle by not heating the passenger compartment. Thereby, only the heating of the aqueous medium that requires the most energy is executed and the heat loss is minimized, thereby realizing efficient preheating.

  Moreover, like 2nd Embodiment, the control part 1 performs switching control of the heating by the electric water heater 25, and the heating by the heat pump section 10 according to the change of the external temperature after the start of preheating, Efficient preheating can be realized even when the outside air temperature changes greatly during preheating.

Further, as shown in FIG. 4B, the control unit 1 monitors the time, and controls so that the preheating is started according to the set time, so that the preheating is performed at a timing convenient for the occupant. It can be performed, and unnecessary preheating operation can be prevented from being performed as much as possible.
As shown in FIGS. 4A and 4B, the control unit 1 monitors the water temperature of the hot water storage tank 25 and controls so that the preheating is started in response to the water temperature becoming equal to or lower than the preheating start determination temperature th4. Thus, useless preheating can be prevented.

The present invention is not limited to the configuration and processing of the above-described embodiment, and various modifications can be considered.
For example, preheating may always be performed during charging. When the start time is checked as shown in FIG. 4B, the preheating may be started when the start time is reached regardless of the water temperature information TW.
Various settings other than the above can be considered for setting the threshold temperature th1, the switching temperatures th2, th3, and the target temperature as the preheating process of FIGS.
Further, depending on the situation, there may be a period during which both heating by the heat pump section 10 and heating by the electric water heater 24 are performed.

  DESCRIPTION OF SYMBOLS 1 ... Control part, 2 ... Temperature sensor, 3 ... Power supply part, 4a, 4b ... Switch, 10 ... Heat pump section, 14 ... Heat exchanger for tanks, 20 ... Hot water heating section, 24 ... Electric water heater, 25 ... Hot water storage tank 27 ... Water temperature sensor, 30 ... Circuit path, 30B ... Bypass path

Claims (4)

A hot water heating unit that stores an aqueous medium heated by an electric water heater in a hot water storage tank, circulates the aqueous medium in the hot water storage tank, and blows warm air into the vehicle interior using a heat exchanger provided in the circulation path;
A heat pump system configured to be capable of heating at least the aqueous medium of the hot water storage tank;
A power supply including a battery;
When preheating the aqueous medium in the hot water storage tank during charging of the battery, a control unit that selects and executes heating by the electric water heater and heating by the heat pump system unit according to an outside temperature; , Bei to give a,
The said control part is a vehicle air conditioner which performs switching control of the heating by the said electric water heater, and the heating by the said heat pump system part according to the change of the external temperature after the start of preheating . The vehicle air conditioner according to claim 1, wherein during the preliminary heating, warm air blowing into the vehicle interior is not performed. The vehicle air conditioner according to claim 1 or 2, wherein the control unit monitors time and performs control so that the preheating is started in accordance with a set time. Wherein the control unit, the water temperature of the hot water storage tank monitoring, the water temperature according to claim 1 or claim 2 for controlling such that said preheating in response to equal to or less than a predetermined pre-heating start determination temperature is started Vehicle air conditioner.

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