JPH08258533A - Air conditioner for electric vehicle - Google Patents

Abstract

PURPOSE: To restrain power used as well, as to blow air at the desired target blast temperature regardless of the difference of the input air temperatures. CONSTITUTION: An air conditioner control means 16 selects the operating mode from the air temperature upstream in the air flowing direction of a car chamber side heat exchanger 3 and the target blast temperature calculated on the basis of various conditions. The operating mode is selected from the optional combination of a car chamber side heat exchanger 3, an electric heater 12, and a mix damper 11. Moreover, the air condition control means 16 selects according to priority the operating mode for performing heating only by the car chamber heat exchanger 3, the operating mode for performing heating by the car chamber side heat exchanger 3 and the electric heater 12, the operating mode for performing heating only by the electric heater 12, and the operating mode for performing cooling by the car chamber side heat exchanger 3 and for performing heating by the electric heater 12 in this order.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for an electric vehicle, and more particularly to an air conditioner for an electric vehicle for air conditioning the inside of a vehicle at a desired blowing temperature regardless of the difference in inlet air temperature.

[0002]

2. Description of the Related Art Conventionally, an air conditioner for an electric vehicle is set in a heating mode or a cooling mode by switching the circulation direction of a heat exchange medium in a heat pump cycle, and heats or cools the air passing through the heat exchanger inside the vehicle. , Warm air or cold air is supplied to the inside of the vehicle. Then, in order to set a desired temperature inside the vehicle, in addition to the set temperature, a target air-blowing temperature is calculated based on various conditions inside and outside the vehicle such as the outside air temperature, the air temperature, and the amount of solar radiation, and based on the target air blowing temperature. By adjusting the circulation amount of the heat exchange medium, the temperature of air blown to the inside of the vehicle is controlled.

[0003]

However, in the conventional air conditioner for an electric vehicle, the heat exchanger inside the vehicle only heats or cools the air passing therethrough.
In a temperature range in which it is close to which of the cooling modes to select, it is difficult to obtain a desired target air blowing temperature. That is, in this temperature range, delicate temperature adjustment is required in the heat exchanger inside the vehicle, but heat exchange based on the circulation amount of the heat exchange medium is almost impossible.

Further, when switching between the heating mode and the cooling mode, it takes time until the heating capacity or the cooling capacity of the heat exchanger inside the vehicle is exerted, so that the blast temperature is not stable during that time and the occupant feels uncomfortable. Is expected.

Furthermore, when heating is switched from the inside air circulation to the outside air introduction during heating, the upstream side air temperature (inlet air temperature) of the heat exchanger inside the unit suddenly drops. Since it takes a predetermined time until the desired heating capacity is exhibited, the measures are insufficient and the same problem as described above occurs.

For this reason, it has been considered that an electric heater is arranged on the downstream side of the heat exchanger inside the vehicle to compensate for insufficient heating, delay in heating, etc. due to only the heat exchanger inside the vehicle. However, it is the current situation that no one has been developed that can perform air conditioning inside the vehicle at a desired blast temperature at the time of mode switching and can suppress power consumption to a necessary minimum.

In view of the above problems, therefore, the present invention not only allows an appropriate operation mode to be selected to reliably perform air conditioning in the vehicle at a desired target air blowing temperature, but also reduces electric power consumption to a necessary minimum. An object is to provide an air conditioning system for automobiles.

[0008]

In order to achieve the above-mentioned object, the present invention heats or cools the passing air by changing the circulation direction of the heat exchange medium in the heat pump cycle, and circulates the heat exchange medium. The heat exchange capacity is adjusted by increasing or decreasing the inside heat exchanger to supply warm air or cold air to the inside of the vehicle, and the inside air heat exchanger is disposed downstream of the inside heat exchanger, the passing air is diverted, and the opening degree is adjusted. A mix damper whose flow rate can be adjusted by adjustment, an electric heater which is arranged in one of the flow paths divided by the mix damper and whose ability to heat passing air can be adjusted, and the vehicle interior heat Inlet temperature detecting means for detecting the inlet air temperature on the upstream side in the air flow direction of the exchanger, and a target blast temperature is calculated based on various conditions inside and outside the vehicle, and an operation mode is selected from the target blast temperature and the inlet air temperature. Do Those having a con control means.

Further, the operation mode selected by the air conditioner control means is such that when the inside of the vehicle is weakly heated and the target air temperature is low, the heating capacity of the heat exchanger inside the vehicle is adjusted by duty control. It is preferable to set the mode to the high temperature side weak warm mode in which the cooling capacity of the heat exchanger inside the vehicle is minimized and the amount of electricity to the electric heater and the opening of the mix damper are adjusted when the target blow temperature is high. .

Further, the air conditioner control means, when the operation modes overlap each other, an operation mode in which the inside heat exchanger alone heats up, an operation mode in which the inside heat exchanger and the electric heater heat up, and an electric heater alone. It is more preferable to preferentially select the operation mode of heating and the operation mode of cooling with the heat exchanger inside the vehicle and heating with the electric heater in this order.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In the electric vehicle air conditioner shown in FIG. 1, the cycle in which the heat exchange medium circulates is switched by the four-way valve 1 between a heating cycle and a cooling cycle. And during these cycles, the four-way valve 1
, A compressor 2, a vehicle interior heat exchanger 3, a vehicle exterior heat exchanger 4, and an accumulator 5 are respectively arranged. Reference numeral 6 is a throttle valve that opens and closes the pipe a by driving the motor 6a.

The four-way valve 1 has a structure in which a rotary body having a pair of communication passages is accommodated in the valve body, and switches according to a control signal from a control device (not shown) as shown by a solid line during heating and during cooling. It switches as shown by the dotted line.

The compressor 2 is driven by the electric power supplied from the compressor driving device 7, and discharges the heat exchange medium sucked inside in a high temperature / high pressure state.

The inside heat exchanger 3 and the outside heat exchanger 4 have a structure in which flat tubes and corrugated fins are laminated and integrated, and when the heat exchange medium flows while meandering through the flat tubes,
It is designed to exchange heat with the air passing through the fins.

The heat exchanger 3 on the inside of the vehicle is disposed in the unit 8 at the front of the vehicle, and radiates heat to heat the passing air during heating and cool it during cooling. On the other hand, the exterior heat exchanger 4
Is attached to the front part of the vehicle and exchanges heat between the heat exchange medium flowing inside and the outside air passing outside.

The accumulator 5 stores a heat exchange medium to separate gas and liquid, and supplies only gas to the compressor 2.

Inside the unit 8, a blower 9, an inside heat exchange temperature sensor 10, a mix damper 11, an electric heater 12 and the like are provided outside the inside heat exchanger 3.

The blower 9 is located upstream of the heat exchanger 3 on the inside of the vehicle, and rotates so as to obtain a desired air volume by sucking the inside air or the outside air into the unit according to the set value input by the blower air volume setting device 13. To do.

The in-vehicle heat exchange temperature sensor 10 is provided in the vicinity of the outlet side of the in-vehicle heat exchanger 3, detects the temperature of the passing air, and outputs it to the air conditioner control device 16 described below.

The mix damper 11 diverts the air that has passed through the heat exchanger 3 inside the vehicle and rotates it to a predetermined opening based on a control signal from the opening adjusting device 14, thereby changing the amount of passing air. Adjust the diversion ratio.

The electric heater 12 is a heat exchanger 3 inside the vehicle.
It is arranged on the downstream side of and heats the passing air. Energization of the electric heater 12 is performed via the heater energization control device 15. As the electric heater 12, a PTC heater or the like capable of preventing excessive rise can be used.

Although the blower unit on the most downstream side of the unit 8 is not shown in the figure, a plurality of dampers are provided inside the blower unit so that a predetermined blower opening can be opened and closed. The air can be blown from a desired position based on the control signal.

An input signal from the blower air volume setting device 13, a temperature detected by the heat exchange temperature sensor 10 inside the vehicle, an outside air temperature,
Various conditions inside and outside the vehicle, such as the inside air temperature, the amount of solar radiation, and the set temperature, are input to the air conditioner controller 16.

Based on these input signals, the air conditioner control device 16 controls the four-way valve control device (not shown), the compressor drive device 7, the opening adjustment device 14, the heater energization control device 15, and the blower air flow control device 17. Cooling and heating operations are controlled by issuing control signals.
In this embodiment, the air conditioning control such as the selection of the operation mode is performed according to the flowchart of FIG.

First, in step S1, the inlet air temperature T _in of the unit 8 is read. In this embodiment, the inlet air temperature T
_in is based on the existing sensor 10 or the like (the outside air sensor and the inside air sensor are not shown), and when the compressor 2 is stopped and the heat exchange medium is in the ventilation mode in which the heat exchange medium 3 does not flow through the inside heat exchanger 3. Is the heat exchange temperature sensor 10 inside the vehicle.
The temperature detected by. Further, when the heat exchange medium is in the heating mode or the cooling mode in which the heat exchange medium flows in the vehicle interior heat exchanger 3 by driving the compressor 2, the outside air temperature is set to the outside air introduction and the inside air temperature is set to the inside air circulation. However, it goes without saying that the inlet air temperature T _in may be detected by separately providing an inlet temperature detection sensor upstream of the vehicle interior heat exchanger 3 _in the unit 8.

Next, in step S2, the target air blowing temperature T _m is calculated based on the various conditions inside and outside the vehicle. The method for calculating the target blowing temperature T _m is the same as the conventional method.

Subsequently, in step S3, the operation mode is determined from the inlet air temperature T _in of the unit 8 and the target air blowing temperature T _m according to the graph of FIG. This graph shows the inlet air temperature T of the unit 8 read in step S1.
_in and the target blast temperature T _m calculated in step S2
It is for determining the operation mode from and.

In the graph, the solid line A indicates the boundary line between cooling and heating. The alternate long and short dash line a ₁ indicates the mode (A / C) in which the heat exchange medium is circulated in the cooling cycle, and the compressor 2
4 shows the relationship between the inlet air temperature T _in and the target blown air temperature T _m when the drive frequency is minimized. The one-dot chain line a ₂
If the cooling by the heat exchanger 3 inside the vehicle becomes more than this,
This shows the lowest temperature T ₀ that is expected to form frost on the interior heat exchanger 3. Furthermore, the alternate long and short dash line a ₃ indicates the maximum temperature T ₂ of the predicted inlet air temperature T _in . The region surrounded by the one-dot chain lines a ₁ , a ₂ and a ₃ is the first cooling mode in which the air passing through the inside heat exchanger 3 alone is cooled. In the area surrounded by the solid line A and the one-dot chain line a ₁ and a ₃ , the compressor 2 is subjected to duty control (control to repeatedly turn on / off the energization to adjust the total energization amount within a predetermined time) to perform heat generation inside the vehicle. This is the second cooling mode in which the air passing through only the exchanger 3 is weakly cooled.

Two-dot chain lines b ₁ and b ₂ are modes (HP) in which the heat exchange medium is circulated in the heating cycle, and the compressor 2
3 shows the relationship between the inlet air temperature T _in and the target blown air temperature T _m when the drive frequency is maximized and when the drive frequency is minimized. The area partitioned by the two-dot chain lines b ₁ and b ₂ is the first heating mode in which the air passing through only the vehicle interior heat exchanger 3 is heated.

The solid lines c ₁ and c ₂ energize the electric heater 12, and the inlet air temperature T _in and the target air blow when the air ratio to the electric heater 12 is maximized and minimized by the mix damper 11. respectively show the relationship between the temperature T _m. The area partitioned by the solid lines c ₁ and c ₂ is the second heating mode in which the air passing therethrough is heated only by the electric heater 12.

Dotted lines d ₁ and d ₂ are the A / C values when the driving frequency of the compressor 2 is minimized, the electric heater 12 is energized, and the air blowing rate to the electric heater 12 is maximized. A / C shows the relationship between the inlet air temperature T _in and the target air temperature T _m when the drive frequency of the compressor 2 is maximized, the electric heater 12 is energized, and the air blowing rate to the electric heater 12 is minimized. Shows. The dotted line d ₃ indicates that the inlet air temperature T _in is the predetermined temperature T _0.
Below, the boundary line where the compressor 2 is not driven by A / C is shown. That is, if the temperature is equal to or lower than T ₀ , frost formation is considered to occur when used for cooling the air passing through the heat exchanger 3 inside the vehicle, and thus cannot be A / C. The area surrounded by the dotted lines d ₁ , d ₂ , d ₃ and a ₃ is the third heating mode in which the air passing through the vehicle interior heat exchanger 3 is dehumidified and cooled and then heated by the electric heater 12.

The region above the two-dot chain line b ₁ is
This is the fourth heating mode in which the air passing through the heat exchanger 3 inside the vehicle and the electric heater 12 is heated. Also, the two-dot chain line b ₂ ,
A region below the dotted line d _{2 and} above the cooling / heating boundary line A is HP in the fifth heating mode in which the duty of the compressor 2 is controlled to heat the air passing through only the vehicle interior heat exchanger 3. is there. Further, an area below the boundary line A and the one-dot chain line a ₂ is an operation mode unsettable area in which air conditioning control is not performed.

From the relationship between the inlet air temperature T _in and the target blown air temperature T _m , the one that consumes less power is selected in the portion where the operation modes overlap. That is, the first heating mode, the fourth heating mode, the second heating mode, and the third heating mode are preferentially selected in this order.

As a result, the operation mode is determined as follows from the relationship between the inlet air temperature T _in and the target air blowing temperature T _m (see to in FIG. 3). That is, in A / C, the normal cooling mode (first cooling mode) in which the air passing through the vehicle interior heat exchanger 3 is cooled, and in A / C, the compressor 2
Duty control of the compressor 2 in a weak cooling mode (second cooling mode) HP for weakly cooling the air passing through the heat exchanger 3 inside the vehicle. In the heating mode (fifth heating mode), A / C, the driving frequency of the compressor 2 is minimized, the electric heater 12 is energized, and the air blowing rate to the electric heater 12 is adjusted, so that the passing air is slightly heated. High temperature side weak heating mode (part of the third heating mode), normal heating mode (first heating mode) for adjusting the drive frequency of the compressor 2 to heat passing air, and electric heater 12 for HP. And a strong heating mode (fourth heating mode) that strongly heats the passing air by adjusting the blowing rate to the electric heater 12. When cooling, the target air temperature is set to T _0.
When the temperature is set to be equal to or lower than 0 ° C, frost is generated on the heat exchanger 3 on the inside of the vehicle. In the present embodiment, the second heating mode in which the air passing therethrough is heated only by energizing the electric heater 12 is not selected, but immediately after the heating operation is started, the warm air is supplied to the inside of the vehicle early. This second heating mode may be selected if necessary.

When the operation mode for air conditioning in the vehicle is determined in this way, the opening degree of the mix damper 11 is determined in step S4. The opening degree of the mix damper 11 is set to 0% when the electric heater 12 is in the off state, and the unit 8 is opened.
All of the air sucked in is allowed to flow to the side opposite to the electric heater 12. If the electric heater 12 is in the ON state, the step S is performed according to the graph shown in FIG.
The opening degree of the mix damper 11 is determined based on the target blowing temperature T _m calculated in 2. For example, when the target blast temperature T _m is 40 ° C. and heating is performed only by the electric heater 12,
The opening degree of the mix damper 11 is 60%. Then, in step S5, the mix damper 11 is drive-controlled to the calculated opening.

As described above, according to the above-described embodiment, the desired target blast temperature T _m is obtained regardless of the difference _in the inlet air temperature T _in.
The operation mode can be selected so that
Moreover, the selected operation mode is the one that requires less power consumption among the applicable operation modes. Therefore, not only the air conditioning in the vehicle that is desirable for the occupant can be performed, but also the power consumption can be suppressed and the predetermined traveling distance can be secured.

Further, not only the air conditioner having the heat pump cycle and the electric heater 12 as described above, but also the air conditioner having a four-way valve only for cooling and the air conditioner having the electric heater similarly consume less power. It is possible to select the operation mode from the viewpoint of In this case, the operation mode in which the inside heat exchanger alone is cooled, the operation mode in which only the electric heater is heated, and the operation mode in which the inside heat exchanger is used for cooling and the electric heater is used are selected in order of priority. do it.

[0039]

As is apparent from the above description, in the present invention, the operation mode is selected so that the desired target air blowing temperature can be obtained irrespective of the difference in the inlet air temperature. It is possible to perform air conditioning inside the vehicle.
In particular, the desired blast temperature can be obtained even when switching from heating to cooling or when switching from inside air circulation to outside air introduction,
No discomfort to passengers.

Further, according to the invention, when the selectable operation modes overlap, the one that consumes less power is selected. According to the invention, the air conditioning inside the vehicle can be performed at a desired air temperature and a predetermined traveling distance can be secured. It becomes possible.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an air conditioner for an electric vehicle according to an embodiment.

FIG. 2 is a flowchart showing air conditioning control according to the present embodiment.

3 is a graph for determining an operation mode from the relationship between the inlet air temperature to the unit of FIG. 1 and the target outlet temperature.

FIG. 4 is a graph showing the relationship between the opening of the mix damper of FIG. 1 and the target outlet temperature.

[Explanation of symbols]

 3 Inside heat exchanger 11 Mix damper 12 Electric heater 16 Air conditioner control device (air conditioner control means)

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] June 29, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0032

[Correction method] Change

[Correction content]

Dotted lines d ₁ and d ₂ are the A / C values when the driving frequency of the compressor 2 is minimized, the electric heater 12 is energized, and the air blowing rate to the electric heater 12 is maximized. A / C shows the relationship between the inlet air temperature T _in and the target air temperature T _m when the drive frequency of the compressor 2 is maximized, the electric heater 12 is energized, and the air blowing rate to the electric heater 12 is minimized. Shows. The dotted line d ₃ indicates that the inlet air temperature T _in is the predetermined temperature T _0.
Below, the boundary line where the compressor 2 is not driven by A / C is shown. That is, if the temperature is equal to or lower than T ₀ , frost formation is considered to occur when used for cooling the air passing through the heat exchanger 3 inside the vehicle, and thus cannot be A / C. The area surrounded by the dotted lines d ₁ , d ₂ , d ₃ and the alternate long and short dash line a ₃ is the third heating mode in which the air passing through the vehicle interior heat exchanger 3 is dehumidified and cooled and then heated by the electric heater 12. .

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

FIG. 3 is a graph for determining an operation mode based on a relationship between an inlet air temperature to the unit of FIG. 1 and a target blowing temperature.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

FIG. 4 is a graph showing the relationship between the opening of the mix damper of FIG. 1 and the target blown temperature.

[Procedure amendment 4]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideaki Nishii Inventor Hideaki Nishii 5658 Yoshikawa, Hachihonmatsu-cho, Higashihiroshima City, Hiroshima Prefecture Japan Climate Systems Co., Ltd.

Claims (3)

[Claims] 1. The heat exchange medium in a heat pump cycle is heated or cooled by changing the circulation direction of the heat exchange medium, and the heating capacity is adjusted by increasing or decreasing the circulation amount of the heat exchange medium to provide warm air inside the vehicle. An in-vehicle heat exchanger that supplies cold air, and a mixed damper that is disposed on the downstream side of the in-vehicle heat exchanger, divides the passing air, and adjusts the opening degree to adjust the divided flow rate, An electric heater disposed in one of the flow paths divided by the mix damper and capable of adjusting the ability to heat passing air, and an inlet air temperature of the inside heat exchanger on the upstream side in the air flow direction is detected. An electrical system comprising: an inlet temperature detecting means; and an air conditioner control means for calculating a target air temperature on the basis of various conditions inside and outside the vehicle and selecting an operation mode from the target air temperature and the inlet air temperature. Dynamic vehicle air conditioning system. 2. The operation mode selected by the air conditioner control means is such that when the inside of the vehicle is weakly heated and the target air temperature is low, the heating capacity of the heat exchanger inside the vehicle is adjusted by duty control. Mode, and when the target blast temperature is on the high temperature side, the cooling capacity of the heat exchanger inside the vehicle is minimized,
The high temperature side weak warming mode for adjusting the amount of electricity to the electric heater and the opening of the mix damper is set.
An air conditioner for the electric vehicle described. 3. The air conditioner control means, when the operation modes overlap with each other, an operation mode in which the heat exchanger inside the vehicle heats only, an operation mode in which the heat exchanger inside the vehicle and an electric heater heat, and an electric heater alone. Operating mode to heat,
3. The air conditioner for an electric vehicle according to claim 1, wherein the operation modes of cooling with the heat exchanger inside the vehicle and heating with the electric heater are selected in order.