Air-conditioning control system

Abstract

To provide an air-conditioning control system which enables reduction of power consumption associated with air-conditioning in a cabin.SOLUTION: A control system A10 comprises: a case 10 in which each of a first passage 11 where air flows down and a second passage 12 where air flowing from the first passage 11 flows down to a cabin are installed; an evaporator 22 which is arranged in the first passage 11 and cools the air flowing down in the first passage 11; a heater core 23 which is arranged at a boundary between the first passage 11 and the second passage 12 and heats the air passing through the evaporator 22; and a controller 30 which controls temperature of heat supplied to the heater core 23. The first passage 11 includes an intermediate path 111 from the evaporator 22 to the heater core 23. The controller 30 uses a value of temperature Ta of the air flowing down the intermediate path 111 as a factor for controlling the temperature of heat supplied to the heater core 23.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates primarily to air conditioning control systems for electric vehicles. [Background technology]

[0002] Patent Document 1 discloses an example of an air conditioning control system for an electric vehicle. The air conditioning control system includes an evaporator, a heater core, and a main heater. The heater core heats air that is cooled by the evaporator or that passes directly through the evaporator. The main heater heats water to supply heat to the heater core. The main heater is operated by electricity. The water heated by the main heater flows into the heater core. This supplies heat to the heater core, enabling the heater core to heat the air.

[0003] In the air conditioning control system disclosed in Patent Document 1, the temperature of heat supplied to the heater core is generally determined based on the outside air temperature. In this case, the temperature of heat supplied to the heater core is uniquely determined regardless of the fluctuation of the air temperature in the flow passage from the evaporator to the heater core. As a result, the power consumption of the main heater that heats the water to supply heat to the heater core tends to increase. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-93561 A Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide an air conditioning control system that is capable of reducing the amount of power consumption associated with vehicle interior air conditioning. [Means for solving the problem]

[0006] The air conditioning control system provided by the present invention includes a case having a first passage through which air flows down and a second passage through which air flowing in from the first passage flows down toward a vehicle interior, an evaporator disposed in the first passage and cooling the air flowing down the first passage, a heater core disposed at a boundary between the first passage and the second passage and heating the air that has passed through the evaporator, and a control device that controls the temperature of heat supplied to the heater core. The first passage includes an intermediate path from the evaporator to the heater core. The control device uses the temperature of the air flowing down the intermediate path as a factor for controlling the temperature of heat supplied to the heater core. Effect of the Invention

[0007] According to the configuration of the air conditioning control system of the present invention, it is possible to reduce the amount of power consumption associated with air conditioning inside the vehicle.

[0008] Other features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic block diagram showing an air conditioning control system according to one embodiment of the present invention. [Diagram 2] 4 is an example of a flowchart for explaining a procedure for controlling the temperature of heat supplied to a heater core. [Diagram 3] 3 is an example of a map of reference temperatures for the temperature control of heat shown in FIG. 2. [Figure 4] 3 is an example of a map of correction temperatures for the temperature control of heat shown in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the accompanying drawings.

[0011] An air conditioning control system (hereinafter referred to as "control system A10") according to one embodiment of the present invention will be described with reference to Fig. 1 to Fig. 4. As shown in Fig. 1, the control system A10 includes a case 10, a blower 21, an evaporator 22, a heater core 23, an air mix door 24, a pipe 25, a heater 26, a pump 27, a control device 30, a first temperature sensor 41, and a second temperature sensor 42. The control system A10 is also called an HVAC (Heating Ventilating and Air Conditioning unit).

[0012] First, the configuration of the control system A10 will be described with reference to FIG.

[0013] The case 10 houses a blower 21, an evaporator 22, a heater core 23, and an air mix door 24. In the control system A10, the air flowing into the case 10 by the blower 21 is temperature-adjusted by the evaporator 22, the heater core 23, and the air mix door 24. The temperature-adjusted air flows out from various air outlets (not shown) provided in the vehicle interior. The case 10 is made of a resin containing, for example, polypropylene.

[0014] A first passage 11 and a second passage 12 are provided inside the case 10. Air flowing into the case 10 by the blower 21 flows down through the first passage 11. The air flowing down through the first passage 11 is cooled by the evaporator 22 or passes through the evaporator 22 as it is, and is heated by the heater core 23. The second passage 12 is located downstream of the first passage 11 in the air flow direction, and is connected to the first passage 11. In the second passage 12, the air cooled by the evaporator 22 or passes through the evaporator 22 as it is in the first passage 11 is mixed with the air heated by the heater core 23 in the first passage 11. The air mixed in the second passage 12 flows down toward various outlets provided in the vehicle interior.

[0015] The first passage 11 includes an intermediate passage 111. The intermediate passage 111 is a passage through which air flows from the evaporator 22 to the second passage 12 in the first passage 11. The intermediate passage 111 includes a first system 111A and a second system 111B. The first system 111A is one system of the intermediate passage 111 that runs from the evaporator 22 to the heater core 23. The second system 111B is the other system of the intermediate passage 111 that runs from the evaporator 22 to the second passage 12 without passing through the heater core 23. Therefore, the air flowing down the first system 111A flows down to the second passage 12 through the heater core 23 and is therefore relatively hot air, whereas the air flowing down the second system 111B flows down to the second passage 12 without passing through the heater core 23 and is therefore relatively cold air.

[0016] The blower 21 is located upstream of the first passage 11 in the direction in which air flows downward. The blower 21 takes in air from a supply port (not shown) of the case 10 into the inside of the case 10, and causes the air to flow downward into the first passage 11. The blower 21 drives a motor (not shown) in response to a command from the control device 30 and rotates a fan (not shown), thereby causing air to flow downward from the outside toward the first passage 11.

[0017] The evaporator 22 is disposed in the first passage 11 of the case 10. The evaporator 22 crosses the first passage 11. The evaporator 22 is an element constituting an air cooling cycle in the control system A10. The air cooling cycle in the control system A10 is constituted by a compressor (not shown), a condenser (not shown), an expansion valve (not shown), and the evaporator 22, in that order. The compressor compresses the refrigerant by electric power or the like. The refrigerant is, for example, hydrofluorocarbon. The condenser condenses and liquefies the compressed refrigerant. The expansion valve reduces the pressure and expands the liquefied refrigerant. The evaporator 22 cools the air by heat exchange accompanying evaporation of the reduced-pressure and expanded refrigerant.

[0018] The first temperature sensor 41 is disposed on a fin (not shown) of the evaporator 22 facing the intermediate path 111 of the first passage 11. The first temperature sensor 41 detects the temperature Te of the fin of the evaporator 22. A detection signal of the first temperature sensor 41 is transmitted to the control device 30.

[0019] The heater core 23 is disposed in the case 10 at the boundary between the first passage 11 (the first system 111A of the intermediate passage 111) and the second passage 12. The heater core 23 heats the air that passes through the evaporator 22 and flows down the first system 111A of the first passage 11. In the control system A10, the heater core 23 heats the air that flows down the first system 111A by heat exchange with water heated by the heater 26.

[0020] The air mix door 24 is disposed in the intermediate passage 111 of the first passage 11 of the case 10. In the control system A10, the air mix door 24 rotates in a direction perpendicular to the air flow direction in the intermediate passage 111. The air mix door 24 rotates by an actuator such as a servo motor. Alternatively, the air mix door 24 may be moved by a rack and pinion mechanism that converts the rotational motion obtained by the actuator into a reciprocating motion. By moving the air mix door 24, the intermediate passage 111 is divided into two, a first system 111A and a second system 111B. This allows the ratio between the amount of air flowing down the first system 111A and the amount of air flowing down the second system 111B to be appropriately adjusted.

[0021] In the intermediate passage 111 of the first passage 11 of the case 10, the ratio of the amount of air flowing down the first system 111A to the amount of air flowing down the second system 111B is determined by the opening degree of the air mix door 24 (the degree of opening of the air mix door 24). In the control system A10, the larger the opening degree of the air mix door 24, the more the amount of air flowing down the first system 111A becomes than the amount of air flowing down the second system 111B. This makes the temperature of the air flowing down the second passage 12 of the case 10 higher. Conversely, the smaller the opening degree of the air mix door 24, the more the amount of air flowing down the second system 111B becomes than the amount of air flowing down the first system 111A. This makes the temperature of the air flowing down the second passage 12 of the case 10 lower.

[0022] Pipe 25 is disposed so as to circulate between the inside of heater core 23 and the inside of heater 26. Water flows through pipe 25 for use in heating heater core 23. Here, the fluid flowing through pipe 25 may be a fluid other than water as long as it is used in heating heater core 23.

[0023] The heater 26 heats the water flowing through the pipe 25. The heater 26 is, for example, a high-voltage heater. The heater 26 converts power supplied from a battery into heat. The pump 27 circulates the water flowing through the pipe 25. In the control system A10, the pump 27 is disposed in the pipe 25 located between the outlet side of the heater core 23 and the inlet side of the heater 26. However, the position of the pump 27 in the pipe 25 is not limited thereto.

[0024] The second temperature sensor 42 is disposed in the pipe 25 located near the inlet side of the heater core 23. The second temperature sensor 42 detects the temperature Tw of the water flowing from the pipe 25 into the heater core 23. A detection signal of the second temperature sensor 42 is transmitted to the control device 30.

[0025] The control device 30 is an ECU (Electric Control Unit) that controls the control system A10. The ECU is realized by a microcomputer equipped with a CPU and a memory. The control device 30 controls the amount of air (air volume) sent out from various outlets provided in the vehicle compartment by controlling the blower 21 according to the setting by the vehicle occupant. The control device 30 controls the temperature of the air sent out from various outlets provided in the vehicle compartment by controlling the opening degree of the air mix door 24 according to the setting by the vehicle occupant. Furthermore, the control device 30 controls the temperature of the heat supplied to the heater core 23.

[0026] The control device 30 includes, as its components, an air volume control unit 31, an opening control unit 32, a target temperature setting unit 33, and a heat control unit .

[0027] The air volume control unit 31 determines the volume of air flowing down the first passage 11 of the case 10 according to settings by a vehicle occupant, etc. Then, the air volume control unit 31 transmits a command to the blower 21 based on the determined air volume information. The blower 21 drives the motor and rotates the fan according to the command transmitted from the air volume control unit 31. The rotation speed of the fan is appropriately changed according to the command from the air volume control unit 31.

[0028] The opening control unit 32 determines the opening degree of the air mix door 24 based on the temperature Te of the fins of the evaporator 22 detected by the first temperature sensor 41 and the temperature Tw of the water flowing into the heater core 23 detected by the second temperature sensor 42, as well as the setting by the vehicle occupant. The opening control unit 32 then transmits a command to the air mix door 24 based on the determined opening degree information. The air mix door 24 drives an actuator in response to the command transmitted from the opening control unit 32, and appropriately adjusts the opening degree of the air mix door 24.

[0029] The target temperature setting unit 33 determines a target temperature Tg of the air flowing down the second passage 12 of the case 10. The target temperature Tg corresponds to a desired temperature of the air to be blown out from various air outlets provided in the vehicle cabin. Factors for determining the target temperature Tg include a predetermined vehicle cabin temperature set by the vehicle occupant, as well as the outside air temperature and the amount of solar radiation. The target temperature setting unit 33 transmits information on the determined target temperature Tg to the air volume control unit 31 and the heat control unit 34. As a result, the air volume control unit 31 determines the amount of air flowing down the first passage 11 of the case 10 based on the setting by the vehicle occupant as well as the determined target temperature Tg.

[0030] The heat control unit 34 determines the set temperature Ts of the heat to be supplied to the heater core 23 based on the target temperature Tg determined by the target temperature setting unit 33. In the control system A10, the set temperature Ts is the value to which the temperature Tw of the water flowing into the heater core 23 should aim. The heat control unit 34 then transmits a command to the heater 26 based on the information of the determined set temperature Ts. The heater 26 appropriately heats the water flowing through the pipe 25 in response to the command transmitted from the heat control unit 34. This controls the temperature of the heat to be supplied to the heater core 23. The heat control unit 34 is transmitted information on the temperature Te of the fins of the evaporator 22 detected by the first temperature sensor 41 and the temperature Tw of the water flowing into the heater core 23 detected by the second temperature sensor 42. The heat control unit 34 is also transmitted information on the amount of air flowing down the first passage 11 of the case 10 determined by the air volume control unit 31.

[0031] Next, a temperature control process of the heat supplied to the heater core 23 by the control device 30 will be described with reference to Fig. 2 to Fig. 4. The temperature control process is executed by the target temperature setting unit 33 and the heat control unit 34 of the control device 30. The temperature control process starts when a predetermined interior temperature is set by a vehicle occupant.

[0032] First, the target temperature setting unit 33 determines the target temperature Tg of the air flowing down through the second passage 12 of the case 10. The target temperature Tg is determined as described above (step S11).

[0033] Next, in the thermal control unit 34, a reference temperature To of heat to be supplied to the heater core 23 is determined based on the target temperature Tg determined by the target temperature setting unit 33 (step S12). The reference temperature To is determined based on a map of the reference temperature To shown in FIG. 3. The map of the reference temperature To is represented by a function with the target temperature Tg as a variable. In the map of the reference temperature To, in addition to the target temperature Tg, the amount of air flowing down the first passage 11 of the case 10 is included as a factor for determining the reference temperature To. The map of the reference temperature To is preset in the thermal control unit 34.

[0034] Next, the heat control unit 34 determines the correction temperature tc (step S13). The correction temperature tc is determined based on a map of the correction temperature tc shown in FIG. 4. The map of the correction temperature tc is represented by a function with Tg-Ta as a variable. Here, Tg-Ta is the difference between the target temperature Tg determined by the target temperature setting unit 33 and the temperature Ta of the air flowing down the intermediate passage 111 of the first passage 11 of the case 10. The temperature Ta of the air flowing down the intermediate passage 111 is approximately equal to the temperature Te of the fins of the evaporator 22 detected by the first temperature sensor 41. Therefore, in the control system A10, Tg-Ta is replaced with Tg-Te (the difference between the target temperature Tg and the temperature Te of the fins of the evaporator 22), and the correction temperature tc is determined based on the map of FIG. 5. The map of the correction temperature tc is preset in the heat control unit 34.

[0035] Next, the heat control unit 34 calculates a set temperature Ts of the heat to be supplied to the heater core 23 (step S14). The set temperature Ts is given as the sum of the previously determined reference temperature To and a correction temperature tc. That is, Ts=To+tc.

[0036] Next, the temperature Tw of the water flowing into the heater core 23 is detected by the second temperature sensor 42 (step S15).

[0037] Next, in the heat control unit 34, the magnitude relationship between the set temperature Ts of the heat supplied to the heater core 23 and the temperature Tw of the water flowing into the heater core 23 is compared (step S16). When the set temperature Ts is higher than the water temperature Tw (Ts > Tw), the heat control unit 34 transmits a command for operating the heater 26 to the heater 26 (step S17). When the set temperature Ts is lower than the water temperature Tw (Ts < Tw), or when the set temperature Ts is equal to the water temperature Tw (Ts = Tw), the heat control unit 34 transmits a command for continuously stopping the heater 26 to the heater 26 (step S18).

[0038] Finally, based on the monitoring by the second temperature sensor 42, until the water temperature Tw reaches the set temperature Ts, the heat control unit 34 transmits an operation or stop command to the heater 26 (step S19). Thus, the temperature control process of the heat supplied to the heater core 23 by the control device 30 is completed. After that, when the setting of a predetermined vehicle interior temperature is changed by the vehicle occupant, or when an environmental change such as a change in the ambient temperature occurs, the temperature control process of steps S11 to S19 described above is executed again.

[0039] In this way, in the control device 30, the value of the temperature Ta of the air flowing down the intermediate path 111 in the case 10 is used as a factor for controlling the temperature of the heat supplied to the heater core 23. Further, in the control device 30, the value of the difference between the target temperature Tg of the air flowing down the second passage 12 in the case 10 and the temperature Ta of the air flowing down the intermediate path 111 is used as a factor for controlling the temperature of the heat supplied to the heater core 23.

[0040] Next, the operation and effect of the control system A10 will be described.

[0041] The control system A10 includes a case 10 having a first passage 11 and a second passage 12 provided therein, an evaporator 22 disposed in the first passage 11, a heater core 23 disposed at the boundary between the first passage 11 and the second passage 12, and a control device 30 for controlling the temperature of heat supplied to the heater core 23. The first passage 11 includes an intermediate passage 111 extending from the evaporator 22 to the heater core 23. In the control device 30, the value of the temperature Ta of the air flowing down the intermediate passage 111 is used as a factor for controlling the temperature of heat supplied to the heater core 23. With this configuration, the temperature Ta of the air flowing down the intermediate passage 111 is taken into consideration when determining the temperature of heat supplied to the heater core 23. As a result, the amount of heat to be supplied to the heater core 23 is controlled in accordance with the current situation, so that the power consumption of the heater 26 can be reduced. Therefore, with this configuration, the control system A10 can reduce the power consumption associated with the air conditioning in the vehicle.

[0042] In the control system A10, the temperature Ta of the air flowing down the intermediate path 111 of the case 10 is substantially equal to the temperature Te of the fins of the evaporator 22 facing the intermediate path 111. This allows the temperature Ta to be replaced with the temperature Te. The temperature Te is detected by the existing first temperature sensor 41. Therefore, in the control system A10, the temperature of the heat supplied to the heater core 23 by the control device 30 can be controlled without increasing the number of parts.

[0043] In the control device 30, the difference between the target temperature Tg of the air flowing down the second passage 12 of the case 10 and the temperature Ta of the air flowing down the intermediate passage 111 of the case 10 is used as a factor for controlling the temperature of heat supplied to the heater core 23. With this configuration, when determining the temperature of heat to be supplied to the heater core 23, the difference between the target temperature Tg corresponding to the desired temperature of the air discharged from various outlets provided in the vehicle compartment and the temperature Ta of the air flowing down the intermediate passage 111 is further taken into consideration. As a result, the amount of heat to be supplied to the heater core 23 is controlled more in accordance with the current situation, so that the power consumption of the heater 26 can be effectively reduced.

[0044] Furthermore, the control device 30 employs a reference temperature To shown in the map of Fig. 3 as a factor for controlling the temperature of heat supplied to the heater core 23. In determining the reference temperature To, the factors used are the target temperature Tg of the air flowing down the second passage 12 of the case 10 and the amount of air flowing down the first passage 11 of the case 10 determined based on the target temperature Tg. This makes it possible to control the amount of heat to be supplied to the heater core 23 while taking into consideration fluctuations in the amount of air (airflow) inside the case 10.

[0045] The present invention is not limited to the above-described embodiment, and the specific configuration of each part of the present invention can be freely designed in various ways. [Explanation of symbols]

[0046] A10: Control system 10: Case 11:1st aisle 111: Middle Road 111A: 1st system 111B: 2nd system 12:Second aisle 21: Blower 22: Evaporator 23: Heater core 24: Air Mix Door 25: Pipeline 26: Heater 27: Pump 30: Control device 31: Air volume control unit 32: Opening control unit 33:Target temperature setting section 34: Thermal control section 41: First temperature sensor 42: Second temperature sensor

Claims

[Claim 1] a case having therein a first passage through which air flows downward and a second passage through which the air flowing in from the first passage flows downward toward a vehicle interior; an evaporator disposed in the first passage and configured to cool air flowing down through the first passage; a heater core disposed at a boundary between the first passage and the second passage and configured to heat air that has passed through the evaporator; A control device for controlling a temperature of heat supplied to the heater core, the first passage includes an intermediate passage extending from the evaporator to the heater core, An air conditioning control system in which the control device uses the temperature value of the air flowing down the intermediate passage as a factor for controlling the temperature of heat supplied to the heater core.

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