JP3446231B2 - Air conditioner for electric vehicle - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for an electric vehicle employing a heat pump refrigeration cycle. 2. Description of the Related Art In an electric vehicle having no internal combustion engine, since a sufficient heat source for heating cannot be secured, a cooling operation and a heating operation are performed by switching a flow direction of a refrigerant circulating in a refrigeration cycle. A heat pump type air conditioner is used. [0003] However, in the above-described heat pump type air conditioner, as the temperature of the outside air decreases, the amount of heat absorbed from the outside air decreases. Therefore, the pressure (low pressure) of the outdoor heat exchanger is reduced. And the refrigerant flow rate circulating through the cycle is significantly reduced. As a result, at the time of the heating operation, there is a problem that the blowing temperature of the hot air obtained by the indoor heat exchanger is reduced and the heating capacity is insufficient. An electric vehicle includes a drive motor (motor) corresponding to an engine of a gasoline vehicle. Therefore, in summer when the outside air temperature is high (for example, about 40 ° C.), the inside of the drive unit that accommodates the drive motor is not heated by the heat generated by the drive motor.
The temperature rises to about 0 ° C. For this reason, in summer, heat is required from fans. Further, even in winter when the outside air temperature is low (for example, about -10 ° C.), the temperature inside the drive unit reaches about 7 to 10 ° C. due to heat generation of the drive motor, and the temperature field is sufficiently higher than the outside air temperature. . For this reason,
When performing heating operation in the outside air mode in winter when the outside air temperature is low, the lack of heating capacity due to a decrease in the amount of heat absorbed from the outside air is taken by taking in the exhaust heat in the drive unit, which is a temperature field higher than the outside air temperature. It is possible to make up for it. The present invention has been made by paying attention to the exhaust heat in the drive unit, and its object is to use the exhaust heat in the drive unit in an air conditioner for an electric vehicle employing a heat pump refrigeration cycle,
The purpose is to improve the heating performance. [0005] In order to achieve the above object, the present invention provides a duct for guiding blast air into a passenger compartment, and a blast means for introducing air into the duct and sending the air into the passenger compartment. A heat pump refrigeration cycle arranged in the duct and having a heating heat exchanger for heating air passing therethrough by heat exchange with the refrigerant, wherein a flow direction of the refrigerant is switched according to an air conditioning mode; Provided at the upstream end of the duct, an inside air introduction port for introducing room air into the duct, an outside air introduction port for introducing outside air into the duct, and an introduction air ratio between the inside air introduction port and the outside air introduction port. An inside / outside air switching means having an inside / outside air switching damper to be adjusted, and a drive unit accommodating a drive motor for traveling communicated with the inside of the duct via the outside air introduction port, and opened outside the vehicle compartment. A communication path having an opening, and a switching means for switching between a first air flow path from inside the drive section to the outside air introduction port and a second air flow path from the opening section to the outside air introduction port within the communication path. And the outside air temperature detection hand that detects the outside air temperature
Stage and temperature detection in the drive unit for detecting the temperature in the drive unit
Means, the temperature detected by the outside air temperature detecting means, and the drive unit
Determine which is higher than the temperature detected by the internal temperature detector
Temperature judging means, in case of outside air mode and heating mode
The detected temperature of the one determined to be higher by the temperature determination means
Control means for controlling the operation of the switching means so that the air having the flow rate is introduced into the duct . In the air conditioner for an electric vehicle according to the present invention having the above-described structure, when the inside / outside air switching damper opens the outside air introduction port (outside air mode), the switching means includes the first air passage and the second air passage. Switch between air flow path. That is, when the first air flow path is selected, the second air flow path is shut off, and when the second air flow path is selected, the first air flow path is shut off. Therefore, when the first air flow path is selected, the air in the drive section is introduced into the duct through the communication path, and when the second air flow path is selected, the outdoor air directly taken in from the opening is provided. Air will be introduced into the duct through the communication passage. Control means is for controlling the operation of the switching means based on the temperature of the outer air temperature and the drive unit, if better temperature in the drive unit from the outside air temperature is high, switching to select the first air passage Controls the operation of the means and controls the temperature in the drive
If the outside air temperature is higher, select the second air flow path
The operation of the switching means is controlled as described above. As a result, when the first air passage is selected, having a temperature higher than the outside air temperature
Since the air in the drive unit is introduced into the duct and blown to the heating heat exchanger, the heating performance is improved as compared with the case where the outdoor air is introduced into the duct to perform the heating operation. Also, the second
If the air flow path is selected, it is higher than the temperature in the drive
Outdoor air having a temperature is introduced into the duct to generate heat for heating.
It is sent to the exchanger. Next, an embodiment of an air conditioner for an electric vehicle according to the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing an external air duct mounting structure, and FIG. 2 is an overall schematic diagram of an air conditioner for an electric vehicle. As shown in FIG. 2, the air conditioner 1 for an electric vehicle according to the present embodiment includes a duct 2 that guides blast air into a vehicle interior, a first blower 3 that introduces air into the duct 2 and sends the air into the vehicle interior. 2 Blower 4, heat pump refrigeration cycle 5 (see FIG. 3, hereinafter refrigeration cycle 5)
), And an air conditioner control device 6 (see FIG. 4). At the downstream end of the duct 2, branch ducts 2 a, 2 b, 2 c for guiding blast air to a defroster outlet 7, a face outlet 8, a side face outlet 9, and a foot outlet 10 which open into the passenger compartment, respectively. 2d is connected. The branch ducts 2a, 2b, 2d communicating with the defroster outlet 7, the face outlet 8, and the foot outlet 10 are respectively opened and closed by a defroster damper 7a, a face damper 8a, and a foot damper 10a that operate according to the selected outlet mode. Is done. First blower 3 and second blower 4
Are installed in parallel at the upstream end of the duct 2. The first blower 3 includes inside / outside air switching means including an inside air introduction port 11 for introducing inside air, an outside air introduction port 12 for introducing outside air, and an inside / outside air switching damper 13 for switching between the inside air introduction port 11 and the outside air introduction port 12. . The second blower 4 always sucks only inside air, and includes an inside air inlet 14. An outside air duct 15 for taking in outside air from outside the vehicle compartment and introducing it into the duct 2 is connected to the outside air inlet 12 of the inside / outside air switching means. This outside air duct 15
The tip opening 15a is opened outside the vehicle compartment,
As shown in FIG. 1, in the middle of the duct, the inside of the drive unit 16 (which corresponds to the engine room of a gasoline vehicle, for example, the inside of a hood) that accommodates a drive motor (not shown) for driving the vehicle communicates. In the outside air duct 15, a first air passage ( FIG. 2) from the inside of the drive unit 16 to the outside air inlet 12 is provided .
A switching damper 17 is provided for switching between a second air flow path (indicated by a dashed arrow in FIG. 2 ) and a second air flow path (indicated by a dashed arrow in FIG. 2 ) from the tip opening 15a to the outside air inlet 12. The switching damper 17 is controlled by the air conditioner control device 6, and closes the first air flow path (the position indicated by the solid line in FIG. 1) and the second air flow path (the broken line in FIG. 1). Position). Therefore, when the outside air mode (the inside / outside air switching damper 13 closes the inside air introduction port 11) is selected, the switching damper 17 closes the first air flow path, so that the tip opening 15a of the outside air duct 15 is opened.
The outside air that has been taken in is introduced into the duct 2 through the outside air duct 15, and the switching damper 17 closes the second air passage, so that the air in the drive unit 16 is introduced into the duct 2 through the outside air duct 15. Will be done. A cooling heat exchanger 18 for cooling air flowing through the duct 2 and a heating heat exchanger 19 for heating the passing air downstream of the cooling heat exchanger 18 are provided in the duct 2. Are located. In the duct 2, a bypass 20 bypassing the heating heat exchanger 19 is provided, and a cool damper 21 for adjusting the opening degree of the bypass 20 is provided in the bypass 20. The cooling heat exchanger 18 is provided over the entire area of the duct 2 so that all of the blast air flowing in the duct 2 can pass through the cooling heat exchanger 18. Upstream of the cooling heat exchanger 18 in the duct 2, the air blown from the first blower 3 and the second blower 4 is divided from the blowers 3 and 4 to the cooling heat exchanger 18 for cooling. A first partition wall 22 for passing the heat exchanger 18 is provided. Downstream of the cooling heat exchanger 18 in the duct 2, a second partition wall 23 that partitions the inside of the duct 2 so that part of the air that has passed through the cooling heat exchanger 18 passes through the heating heat exchanger 19. Is provided. The second partition wall 23 is provided to the downstream side of the heating heat exchanger 19, and the opening and closing damper 2 is provided downstream of the second partition wall 23.
4 are provided. The opening / closing damper 24 is connected to the duct 2
The air passages formed on both sides of the second partition wall 23 can communicate with each other, and are provided to open in a face mode or a defroster mode. The heat exchanger 19 for heating is connected to the duct 2 while passing through the second partition wall 23.
Is located within. As shown in FIG. 3, in addition to the cooling heat exchanger 18 and the heating heat exchanger 19, the refrigeration cycle 5 includes a refrigerant compressor 25, an outdoor heat exchanger 26, and a decompression device 2.
7, an accumulator 28, and a flow path switching means (described later). The cooling heat exchanger 18 functions as a refrigerant evaporator, and cools the passing air by heat exchange with a low-temperature, low-pressure refrigerant. The heating heat exchanger 19 performs the function of a refrigerant condenser, and heats the passing air to a high temperature.
Heating by heat exchange with high pressure refrigerant. Refrigerant compressor 2
Numeral 5 performs suction, compression and discharge of the refrigerant, and is driven by the electric motor 29. This refrigerant compressor 25 is disposed in a sealed case 30 integrally with the electric motor 29. The rotation speed of the electric motor 29 that drives the refrigerant compressor 25 is variable under the control of the inverter 31, and the refrigerant discharge amount of the refrigerant compressor 25 changes according to the change in the rotation speed of the electric motor 29. The outdoor heat exchanger 26 is
An outdoor fan 3 which is disposed outside the duct 2 and exchanges heat between the outside air and the refrigerant and blows air to the outdoor heat exchanger 26
2 and an outside air shutter 33. The decompression device 27
The refrigerant flowing into the cooling heat exchanger 18 is decompressed and expanded, and is provided, for example, so as to adjust the supercool amount of the heating heat exchanger 19 during the dehumidifying operation. The accumulator 28 temporarily stores the excess refrigerant in the refrigeration cycle 5 and sends out only the gas-phase refrigerant in order to prevent the refrigerant compressor 25 from sucking the liquid refrigerant. The flow path switching means switches the flow direction of the refrigerant during a cooling operation, a heating operation, and a dehumidifying operation.
Specifically, a four-way valve 34 for switching the discharge direction of the refrigerant compressor 25, an electromagnetic on-off valve 35 for bypassing the cooling heat exchanger 18 during the heating operation, and the heating heat exchanger 1 during the cooling operation
It comprises an electromagnetic three-way valve 36 for bypassing the valve 9 and a check valve 37 for regulating the flow direction of the refrigerant. The flow path switching means switches the flow of the refrigerant in the following manner according to the cooling operation, the heating operation, and the dehumidifying operation. a) Refrigerant discharged from the refrigerant compressor 25 during the cooling operation is bypassed by the four-way valve 34 → the outdoor heat exchanger 26 → the heating heat exchanger 19, and the pressure reducing device 27 → the cooling heat exchanger 18 → the four-way valve 34. The flow is switched so as to flow from the accumulator 28 to the refrigerant compressor 25 (the flow of the refrigerant is indicated by an arrow C in the figure). b) The refrigerant discharged from the refrigerant compressor 25 at the time of the heating operation is a four-way valve 34 → the heat exchanger 19 for heating → the pressure reducing device 27 → the heat exchanger 18 for cooling.
The outdoor heat exchanger 26 (outdoor fan 32O)
N, the outside air shutter 33 is opened) → the four-way valve 34 → the accumulator 28 → the refrigerant compressor 25 is switched to flow in this order (the flow of the refrigerant is indicated by an arrow H in the figure). c) The refrigerant discharged from the refrigerant compressor 25 at the time of the dehumidification operation is a four-way valve 34 → the heat exchanger 19 for heating → the pressure reducing device 27 → the heat exchanger 18 for cooling.
→ The outdoor heat exchanger 26 (the outdoor fan 32 is turned off, the outdoor air shutter 33 is closed) → the four-way valve 34 → the accumulator 28 → the refrigerant compressor 25 is switched to flow in this order (the flow of the refrigerant is indicated by an arrow D in the figure). The air conditioner control device 6 (see FIG. 4)
A microcomputer including an M6a, a RAM 6b, a CPU 6c, and the like, based on an operation signal output from an air conditioner operation panel 38 and a detection signal from each sensor (described later), a first blower 3, a second blower 4, Inverter 31, outdoor fan 32, four-way valve 3 of motor 29
4, electromagnetic on-off valve 35, electromagnetic three-way valve 36, each damper 7a,
8a, 10a, 13, 17, 21, and 24 and an electric component such as an actuator (not shown) for driving the outside air shutter 33 are energized. The sensors include an inside air sensor 39 for detecting a vehicle interior temperature Tr, an outside air sensor 40 for detecting an outside air temperature Tam, a solar radiation sensor 41 for detecting an amount of solar radiation Ts, a vehicle speed sensor 42 for detecting a vehicle speed H, and the like (see FIG. 4). .
The air conditioner operation panel 38 includes a temperature setting means 43 for setting the room temperature desired by the occupant,
An auto switch 4 for instructing the air conditioner control device 6 to automatically control the electric components so as to maintain the temperature set at 3
4, an outlet mode switch 45 for selecting each of the outlets 7 to 10, an inside / outside air mode switch 46 for designating an inside air mode and an outside air mode, and a fan switch 47 for adjusting the air volume of each of the blowers 3 and 4. (Fig. 4
reference). Next, the operation of the air conditioner control device 6 for controlling the switching damper 17 will be described with reference to the flowchart shown in FIG. The following operation is control when the outside air mode is set with the auto switch 44 turned on. First, the outside temperature Tam and the vehicle speed H detected by the outside air sensor 40 and the vehicle speed sensor 42 are input (step 10).
0). Next, from the information (outside temperature Tam, vehicle speed H) obtained in step 100, the temperature Tg of the drive unit 16 is calculated based on the data stored in the ROM 6a in advance (step 110). The ROM 6a stores data (see FIG. 6) indicating the relationship between the outside air temperature Tam for each vehicle speed and the temperature Tg of the drive unit 16. Next, with respect to the heat balance of the vehicle, the target outlet temperature TAO calculated by the following equation:
The required heat amount Qao is calculated based on the difference between the current heat amount and the current vehicle interior temperature Tr based on the following equation (step 120), and it is determined from the required heat amount Qao whether heating or cooling is required (step 130). TAO = Kset · Tset−Kr · Tr−Kam · Tam−Ks · Ts + C where Kset: temperature setting constant, Kr: inside air temperature constant, T
set: outside air temperature constant, Ks: solar radiation constant, C: correction constant. ## EQU2 ## Qao = Cp.gamma.Va.times. (TAO-Tr) = Cp.gamma..Va.times. {Kset.Tset- (Kr + 1) .times.Tr-Kam.Tam-Ks.Ts + C}... ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… ·························
a: Air volume. If it is determined in step 130 that cooling is necessary, the switching damper 17 is controlled so as to close the first air passage (step 150). As a result, the outside air taken in from the distal end opening 15a of the outside air duct 15 passes through the outside air duct 15 and is introduced into the duct 2 from the outside air inlet 12. If it is determined in step 130 that heating is necessary, step 140 compares the outside air temperature Tam with the temperature Tg of the inside of the drive unit 16, and the outside air temperature Tam is higher than the temperature Tg of the inside of the drive unit 16. If it is higher (YES), the switching damper 17 is controlled so as to close the first air flow path (step 150). As a result, the outside air taken in from the distal end opening 15a of the outside air duct 15 passes through the outside air duct 15 and is introduced into the duct 2 from the outside air inlet 12. If it is determined in step 140 that the temperature Tg of the drive unit 16 is higher than the outside air temperature Tam (NO), the switching damper 17 is controlled so as to close the second air flow path (step 16).
0). As a result, the air in the drive unit 16 is
5 and is introduced into the duct 2 from the outside air inlet 12. As a result, during the heating operation, if the temperature Tg of the drive unit 16 is higher than the outside temperature Tam, the air in the drive unit 16 having a higher temperature is introduced into the duct 2 to increase the heating efficiency and insufficient heating. Can be eliminated. In this embodiment, the first blower 3 and the second blower 3
Although the blowers 4 are installed independently of each other, the motors of the first blower 3 and the second blower 4 can be shared.
Alternatively, the motor and the fan of the first blower 3 and the second blower 4 may be shared. Further, in the above-described embodiment, the operation of the inside / outside air switching damper 13 is controlled based on both the outside air temperature and the temperature of the inside of the drive unit 16. However, since the temperature of the inside of the drive unit 16 has a correlation with the outside air temperature, The operation of the inside / outside air switching damper 13 may be controlled based on only the outside air temperature. The air conditioner for an electric vehicle according to the present invention has the following features.
When the temperature inside the drive unit is higher than the outside air temperature, the air in the drive unit with the higher temperature is introduced into the duct and blown to the heating heat exchanger to increase the heating efficiency and reduce the temperature when the outside temperature is low. The lack of heating can be eliminated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing an external air duct mounting structure according to the present embodiment. FIG. 2 is an overall schematic diagram of an air conditioner for an electric vehicle. FIG. 3 is a refrigeration cycle diagram of the air conditioner for an electric vehicle. FIG. 4 is a block diagram related to control of the present embodiment. FIG. 5 is a flowchart showing the operation of the air conditioner control device. FIG. 6 is a graph showing a relationship among a vehicle speed, an outside air temperature, and a temperature inside a driving unit. [Description of Signs] 1 Air conditioner for electric vehicle 2 Duct 3 First blower (blower means) 5 Heat pump refrigeration cycle 6 Air conditioner controller (controller) 11 Inside air inlet 12 Outside air inlet 13 Inside / outside air switching damper 15 Outside air Duct (communication passage) 15a Tip opening (opening) 16 Inside drive unit 17 Switching damper (switching means) 19 Heat exchanger for heating

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-155827 (JP, A) JP-A-5-4511 (JP, A) Jikai Sho 56-43612 (JP, U) (58) Survey Field (Int.Cl. ⁷ , DB name) B60H 1/00-3/06

Claims (1)

(57) [Claims 1] a) a duct for guiding blast air into a vehicle compartment; b) a blast means for introducing air into the duct and transmitting the air into the vehicle compartment; and c) the duct. A heat pump refrigeration cycle having a heating heat exchanger that heats air passing therethrough by heat exchange with the refrigerant, wherein the flow direction of the refrigerant is switched according to an air conditioning mode; and An indoor air inlet for introducing room air into the duct, an outside air inlet for introducing outdoor air into the duct, and a ratio of air introduced between the inside air inlet and the outside air inlet are provided at an upstream end. E) an inside / outside air switching means having an inside / outside air switching damper, and e) communicating between the inside of the duct and the inside of the drive unit accommodating the driving motor for traveling via the outside air introduction port.
A communication passage having an opening that opens outside the vehicle compartment; f) a first air flow path from inside the driving section to the outside air introduction port and a second air from the opening section to the outside air introduction port in the communication passage. Switching means for switching between the flow path; g) an outside air temperature detecting means for detecting an outside air temperature; h) a temperature detecting means in the driving section for detecting a temperature in the driving section.
And i) a temperature detected by the outside air temperature detecting means and an internal temperature of the driving unit.
Temperature to determine which is higher than the temperature detected by the temperature detection means
J) determining means for determining the temperature in the outside air mode and the heating mode;
The air with the detected temperature determined to be higher by the
Control means for controlling the operation of the switching means so as to be introduced into the duct .