Vehicle air-conditioning system

Abstract

To suppress energy consumption during heating operation inside a cabin.SOLUTION: In an air-conditioning system, when opening and closing control of a grille shutter is performed during heating operation using a heater core, an outside air temperature Ta and a water temperature Tw are detected (Step 104). When the outside air temperature Ta is lower than the water temperature Tw, the grille shutter is set to be fully closed (Steps 106, 110). When the outside air temperature Ta is higher than the water temperature Tw, the grille shutter is opened. Here, an opening degree of the grille shutter is set according to the outside air temperature Ta, a temperature difference Td between the outside air temperature Ta and the water temperature Tw, and a vehicle speed V (Steps 108, 112-116). As a result, it is possible to suppress increase in air resistance in a state where a heat absorption effect from outside air cannot be obtained, so that it is possible to suppress consumption of energy (power) in a vehicle.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a vehicle air conditioning system. [Background technology]

[0002] Patent Document 1 discloses an air conditioning system for an electric vehicle that includes an outside air temperature sensor that detects the outside air temperature, a radiator through which coolant that cools a heat source is circulated, a radiator fan that increases the flow rate of outside air passing into the radiator, active grill shutters that allow outside air to enter and block the radiator, a compressor that pressurizes refrigerant, a condenser through which the refrigerant pressurized by the compressor is circulated and to which outside air that has been heat exchanged by the radiator is supplied, and an air conditioning control device that drives and controls the opening and closing of the active grill shutter based on a set temperature and the outside air temperature during heating operation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-008247 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the opening and closing of the active grill shutter is controlled based on the set temperature during heating operation and the outside air temperature. Normally, during heating operation, the set temperature is higher than the outside air temperature and the active grill shutter is open, so there is room for improvement in reducing the energy consumption in the vehicle.

[0005] The present invention has been made in view of the above circumstances, and has an object to provide a vehicle air conditioning system that can reduce energy consumption during heating operation in the passenger compartment. [Means for solving the problem]

[0006] In order to achieve the above object, the vehicle air conditioning system of claim 1 includes: a heater core in which, when generating air conditioning air for conditioning the interior of the vehicle, heat exchange occurs between a heat medium circulated during heating operation in the vehicle cabin and the air conditioning air; an outside air heat absorption section in which outside air is introduced and heat is absorbed by the heat medium circulated from the outside air and input, thereby enabling heat to be absorbed from the heat medium to the heat medium circulated to the heater core; a grill shutter that is arranged to be able to open and close a grill opening that opens toward the front of the vehicle, and that allows outside air in front of the vehicle to be introduced into the outside air heat absorption section by opening the grill opening; a first temperature detection section that detects a first temperature as the temperature of the heat medium input to the outside air heat absorption section; a second temperature detection section that detects a second temperature as the temperature of the outside air introduced into the outside air heat absorption section; and a control section that controls the grill shutter to open the grill opening when the first temperature is lower than the second temperature when the interior of the vehicle is heated.

[0007] In the vehicle air conditioning system of claim 1, when generating conditioned air for conditioning the vehicle cabin, heat exchange is carried out between the heat medium circulated in the heater core during heating operation of the vehicle cabin and the air to be conditioned (conditioned air), to generate conditioned air for heating.

[0008] In addition, in the outside air heat absorption section, by introducing outside air, heat is absorbed by the heat medium circulated from the outside air and input, and heat can be absorbed from the heat medium absorbing heat from the outside air to the heat medium circulated to the heater core. Note that the heat medium circulated through the heater core and the heat medium circulated through the outside air heat absorption section may be the same heat medium or different heat media. When the heat medium circulated through the heater core and the heat medium circulated through the outside air heat absorption section are different, it is sufficient that a function for exchanging heat between the circulation circuits of the respective heat media (a heat exchange section such as a heat exchanger) is provided and they are thermally connected.

[0009] A vehicle is provided with a grill opening that opens toward the front of the vehicle, and a grill shutter is disposed at the grill opening. The grill shutter opens the grill opening to allow outside air in front of the vehicle to be introduced into the outside air heat absorption section, but generates air resistance in the vehicle.

[0010] The first temperature detection unit detects a first temperature as the temperature of the heat medium input to the outside air heat absorption unit, and the second temperature detection unit detects a second temperature as the temperature of the outside air introduced into the outside air heat absorption unit.

[0011] In the vehicle, air resistance increases when the grill opening is opened, and air resistance decreases when the grill opening is closed. When the first temperature is lower than the second temperature during heating of the vehicle interior, the control unit controls the grill shutter to open the grill opening.

[0012] As a result, when the second temperature is lower than the first temperature and the heat absorption effect is low during heating of the vehicle cabin, the grill shutter can be prevented from opening the grill opening, thereby preventing an increase in the vehicle's air resistance and reducing energy consumption in the vehicle.

[0013] The vehicle air conditioning system of claim 2 is based on claim 1, and includes a configuration in which the control unit increases an opening degree of the grill opening by the grill shutter as a temperature difference between the first temperature and the second temperature increases.

[0014] In the vehicle air conditioning system of claim 2, the control unit changes the opening degree of the grill opening according to the temperature difference between the first temperature and the second temperature. In this case, the control unit increases the opening degree of the grill opening as the temperature difference between the first temperature and the second temperature increases. Since a large temperature difference between the first temperature and the second temperature increases the amount of heat absorbed from the outside air, the heating efficiency using the heater core can be improved. In addition, when the temperature difference between the first temperature and the second temperature is small, the opening degree of the grill opening is reduced, so that air resistance can be reduced and energy consumption can be suppressed.

[0015] The vehicle air conditioning system of claim 3 is based on claim 1 or 2, and further includes a configuration in which the control unit reduces an opening degree of the grill opening portion by the grill shutter as the second temperature becomes lower.

[0016] In the vehicle air conditioning system of claim 3, since the lower the second temperature, the less heating capacity is achieved by using outside air, the control unit controls the grill shutter to open the grill opening less as the second temperature decreases. This makes it possible to suppress an increase in the air resistance of the vehicle and thus suppress energy consumption for driving.

[0017] The vehicle air conditioning system of claim 4 is any one of claims 1 to 3, further including a vehicle speed detection unit that detects vehicle speed, and the control unit includes a control unit that increases the opening degree of the grill opening by the grill shutter as the vehicle speed increases.

[0018] In the vehicle air conditioning system of claim 4, the opening degree of the control unit grille opening is changed according to the vehicle speed detected by the vehicle speed detection unit. At this time, the control unit increases the opening degree of the grille opening by the grille shutter as the vehicle speed increases. Since a large amount of heat can be absorbed from the outside air by the high vehicle speed, the heating efficiency using the heater core can be improved. In addition, when the vehicle speed is low, the opening degree of the grille opening can be made smaller compared to when the vehicle speed is high, so that the air resistance can be reduced and energy consumption can be suppressed. Effect of the Invention

[0019] According to the present invention, it is possible to suppress the energy consumption of a vehicle during heating operation of the vehicle interior using a heater core. [Brief description of the drawings]

[0020] [Figure 1] 1 is a schematic configuration diagram of a main part of an air conditioning system according to an embodiment of the present invention. [Figure 2A] 1 is a diagram showing the opening and closing of a grill shutter in response to the temperature difference between the outside air temperature and the water temperature. [Figure 2B] 4 is a diagram showing an outline of the opening degree of the grill shutter relative to the vehicle speed and the outside air temperature. [Diagram 3] 5 is a flow chart showing opening and closing control of the grill shutter during heating in the present embodiment. [Figure 4A]FIG. 13 is a diagram showing the results of a simulation of power consumption versus the opening degree of the grill shutter corresponding to outside air temperatures T1 and -T2 at a speed (vehicle speed) V0. [Figure 4B] FIG. 1 is a diagram showing the results of a simulation of power consumption versus the opening degree of the grill shutter corresponding to outside air temperatures T1 and -T2 at a speed (vehicle speed) V1. [Figure 4C] FIG. 13 is a diagram showing the results of a simulation of power consumption versus the opening degree of the grill shutter corresponding to outside air temperatures T1 and -T2 at a speed (vehicle speed) V2. [Figure 4D] FIG. 13 is a diagram showing the results of a simulation of power consumption versus the opening degree of the grill shutter corresponding to outside air temperatures T1 and -T2 at a speed (vehicle speed) V3. [Diagram 5] FIG. 1 is a diagram showing an outline of reduced energy versus speed (vehicle speed) for each outside air temperature. [Figure 6] FIG. 11 is a schematic configuration diagram of a main part of an air conditioning system according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The present embodiment will be described in detail below with reference to the drawings. The air conditioning system 10 as a vehicle air conditioning system according to this embodiment is applied to an electric vehicle (BEV: Battery Electric Vehicle) that uses an electric motor as a driving source for traveling, and is responsible for air conditioning (cooling and heating) of the vehicle interior in the electric vehicle. The air conditioning system 10 can also include a cooling function for a power train system, a storage battery system, etc. in the vehicle.

[0022] The air conditioning system 10 includes an air conditioning unit (not shown) for blowing conditioned air into the vehicle cabin, and includes a heater core 20 for heating the vehicle cabin and an evaporator 38 for cooling and dehumidifying the vehicle cabin. In the air conditioning system 10, the air conditioning unit operates a blower fan to introduce outside air (air outside the vehicle) or inside air (air inside the vehicle cabin), and the introduced air passes through the evaporator 38, or between the evaporator 38 and the heater core 20, whereby the temperature of the air is adjusted and conditioned air is generated.

[0023] In the air conditioning system 10, during heating (heating operation), conditioned airflow for heating (heated airflow) is generated by increasing the amount of air passing through the heater core 20 while suppressing the cooling of the air by the evaporator 38. As a result, in the air conditioning system 10, the conditioned air generated in the air conditioning unit is blown into the vehicle compartment from the air outlet, thereby conditioning (heating) the vehicle compartment. A known configuration can be applied to the basic configuration of such an air conditioning system 10.

[0024] FIG. 1 shows a heat medium circulation circuit as a schematic diagram of the main part of an air conditioning system 10 according to this embodiment.

[0025] As shown in Fig. 1, a heat pump system is applied to an air conditioning system 10, and the air conditioning system 10 includes water circulation circuits 12, 14 and a refrigerant circuit 16. Water is applied as a heat medium to each of the water circulation circuits 12, 14. A refrigerant is applied as a heat medium to the refrigerant circuit 16, and a refrigeration cycle in which the refrigerant is circulated is formed in the refrigerant circuit 16. Note that only main functional components are shown in the drawing, and for example, reservoir tanks and the like are omitted from the water circulation circuits 12, 14, and a modulator and the like are omitted from the refrigerant circuit 16.

[0026] The water circulation circuit 12 includes the heater core 20, an electric water pump (W / P) 22, and a condenser (water-cooled condenser) 24, and the water-cooled condenser 24 is disposed across the refrigerant circuit 16. The water circulation circuit 14 will be described later.

[0027] In the water circulation circuit 12, when the W / P 22 is driven, water is circulated from the W / P 22 through the water-cooled condenser 24 to the heater core 20. In addition, in the water circulation circuit 12, a water temperature sensor 26 is disposed on the water-cooled condenser 24 side of the heater core 20, and in the water circulation circuit 12, the water temperature sensor 26 detects the temperature of the water flowing into the heater core 20.

[0028] In the water circulation circuit 12, heat exchange occurs between the air passing through the heater core 20 and the water, and in the water-cooled condenser 24, heat exchange occurs between the water and the refrigerant circulating through the refrigerant circuit 16. At this time, in the water circulation circuit 12, the temperature of the water flowing through the water-cooled condenser 24 is lower than the temperature of the refrigerant flowing through the refrigerant circuit 16, so that the water is heated by the refrigerant and the refrigerant is cooled by the water. Also, in the water circulation circuit 12, the temperature of the water passing through the heater core 20 is higher than the temperature of the air passing through the heater core 20, so that the air passing through the heater core 20 is heated (warmed) to generate conditioned air for heating.

[0029] The water circulation circuit 12 may be provided with a heating unit such as an electric heater, so that when the required water temperature cannot be obtained during heating, the water can be heated by the electric heater to obtain the required water temperature. This makes it possible to prevent passengers from feeling uncomfortable due to insufficient heating capacity in the air conditioning system 10.

[0030] The refrigerant circuit 16 is formed with a main circuit 30 and a branch circuit 32 branched (bypassed) from the main circuit 30. The main circuit 30 is provided with a compressor 36, a water-cooled condenser 24, an electric (motorized) expansion valve 34A, and the evaporator (heat radiator) 38. The branch circuit 32 is provided in parallel with the range from the expansion valve 34A of the main circuit 30 to the compressor 36 side of the evaporator 38. The branch circuit 32 is provided with an electric expansion valve 34B and a chiller 40, and the chiller 40 is provided between the water circulation circuit 14.

[0031] A fin thermistor 42 for detecting the temperature of the fins is disposed in the evaporator 38 of the refrigerant circuit 16. In addition, pressure sensors 44A, 44B for detecting the refrigerant pressure, a ph (pressure-enthalpy) sensor 46, and the like are disposed in the refrigerant circuit 16. The pressure sensor 44A is disposed on the compressor 36 side of the evaporator 38 in the main circuit 30, and the pressure sensor 44B is disposed on the compressor 36 side of the chiller 40 in the branch circuit 32. In addition, the ph sensor 46 is disposed between the water-cooled condenser 24 and the expansion valve 34A in the main circuit 30.

[0032] In the refrigerant circuit 16, the compressor 36 is rotationally driven by the torque of an electric motor (not shown), whereby the refrigerant is compressed and discharged, and in the main circuit 30, the refrigerant is circulated to the compressor 36 via the water-cooled condenser 24, the expansion valve 34B, and the evaporator 38. Also, in the refrigerant circuit 16, the refrigerant is circulated to the chiller 40 via the expansion valve 34B in the branch circuit 32.

[0033] In the refrigerant circuit 16, the rotation speed (refrigerant pressure, circulating amount of refrigerant, etc.) of the compressor 36 is controlled according to the detection results of the fin thermistor 42, the pressure sensor 44A, the pressure sensor 44B, and the pH sensor 46. Also, in the refrigerant circuit 16, the flow (flow rate) of refrigerant to each of the evaporator 38 (main circuit 30) and the chiller 40 (branch circuit 32) is controlled by the expansion valves 34A, 34B.

[0034] As a result, in the refrigerant circuit 16, conditioned air for cooling and dehumidification is generated by the evaporator 38 in the air conditioning unit in the main circuit 30. Also, in the refrigerant circuit 16, heat exchange is possible in the chiller 40 of the branch circuit 32 between the refrigerant and the water flowing on the water circulation circuit 14 side.

[0035] Meanwhile, the water circulation circuit 14 of the air conditioning system 10 is provided with a chiller 40, a radiator 50 as an outside air heat absorption section, and an electric water pump (W / P) 52. In the water circulation circuit 14, the W / P 52 is operated to circulate water that has passed through the chiller 40 so that it is sent to the radiator 50. Also, the water circulation circuit 14 is provided with a water temperature sensor 54 as a first temperature detection section, and the water temperature sensor 54 detects the temperature of the water flowing into the radiator 50 (water before it is heat exchanged with the outside air).

[0036] In the air conditioning system 10, the radiator 50 is disposed at the front of the vehicle. Also, the vehicle has a grill opening (not shown) formed at the front end (front grill, on the vehicle front side of the radiator 50) and opened toward the front of the vehicle, and a grill shutter 56 is disposed at the grill opening (not shown).

[0037] A plurality of fins 58 are arranged on the grill shutter 56. The plurality of fins 58 are arranged vertically with their longitudinal direction being the vehicle width direction, and their support shafts at the middle parts in the width direction intersecting with the vehicle width direction are rotatably supported by a frame (not shown) attached to the grill opening. The plurality of fins 58 are tilted together by an actuator (not shown) about the support shaft.

[0038] The grill shutter 56 closes (fully closes) the grill opening by orienting one end side in the width direction of each of the fins 58 downward (see solid line in FIG. 1), and opens (fully opens) the grill opening by orienting one end side in the width direction toward the front of the vehicle (see two-dot chain line in FIG. 1). Also, the grill shutter 56 is configured so that the tilt angle of the fins 58 can be changed continuously or stepwise between the fully closed position and the fully open position. This allows the opening degree of the grill shutter 56 to be changed between the fully closed position and the fully open position.

[0039] The grill shutter 56 blocks the introduction of air from the front of the vehicle through the grill opening by closing the grill opening with the fins 58. In addition, the grill shutter 56 allows air to be introduced from the grill opening at a flow rate according to the opening degree of the grill opening and the vehicle speed by tilting the fins 58 to open the grill opening.

[0040] In a vehicle, air resistance is reduced when the grill shutter 56 is closed, and air resistance is increased when the grill shutter 56 is opened. In this case, in the vehicle, air resistance increases as the opening degree of the grill shutter 56 increases, and the degree of decrease in energy efficiency (energy consumption) increases.

[0041] In addition, in the air conditioning system 10, when the grille shutter 56 is opened, air in front of the vehicle (hereinafter referred to as outside air) is introduced from the grille opening and passes through the radiator 50. In the water circulation circuit 14 of the air conditioning system 10, heat is exchanged between the outside air passing through the radiator 50 and the water. Therefore, in the air conditioning system 10, when the temperature of the outside air is higher than the temperature of the water flowing into the radiator 50, the water absorbs heat from the outside air, and when the temperature of the outside air is lower than the temperature of the water flowing into the radiator 50, the water releases heat (cools).

[0042] In addition, a fan shroud and a cooling fan (both not shown) are provided on the vehicle rear side of the grill shutter 56, and the radiator 50 is covered by the fan shroud. Therefore, even when the vehicle is stopped (vehicle speed is zero), the grill shutter 56 is opened and the cooling fan is operated, so that air introduced from the grill opening passes through the radiator 50.

[0043] The air conditioning system 10 is provided with a control unit 60. The control unit 60 has a microcomputer in which a CPU, a ROM, a RAM, a non-volatile storage, etc. are connected by a bus. In the control unit 60, the CPU reads out programs such as an air conditioning control program stored in the ROM and the storage, and executes them while expanding them in the RAM, thereby realizing a function of controlling the air conditioning in the vehicle cabin (air conditioning control function), etc.

[0044] The control unit 60 is electrically connected to an operation panel (not shown) for making various settings for air conditioning in the vehicle cabin, various sensors provided in the air conditioning system 10, and various actuators such as an electric motor for driving the compressor 36 and an actuator for opening and closing the grill shutter 56 (tilting the fins 58) (not shown). As a result, the control unit 60 conditions the air in the vehicle cabin by controlling the driving of the compressor 36 and the like in accordance with various settings made by the occupant on the operation panel and the detection results of the various sensors. Note that known controls can be applied to the basic control of the air conditioning system 10, and detailed explanations thereof will be omitted below.

[0045] The air conditioning system 10 is provided with an outside air temperature sensor 62 as a second temperature detection unit for detecting the outside air temperature introduced through the grill opening, and the outside air temperature sensor 62 is electrically connected to the control unit 60. In addition, the control unit 60 is electrically connected to a vehicle speed sensor 64 as a vehicle speed detection unit for detecting the vehicle speed (vehicle speed).

[0046] In the air conditioning system 10, when the heater core 20 is used to heat the vehicle interior, the control unit 60 controls the opening and closing of the grill shutter 56 in accordance with the outside air temperature detected by the outside air temperature sensor 62 and the water temperature on the inlet side of the heater core 20 of the water circulation circuit 12. In controlling the opening and closing of the grill shutter 56, the control unit 60 also uses the vehicle speed detected by the vehicle speed sensor 64 in addition to the outside air temperature and water temperature.

[0047] Meanwhile, the vehicle (electric vehicle) in which the air conditioning system 10 is mounted is provided with a drivetrain (powertrain system) for vehicle running. That is, the vehicle is equipped with a transaxle (FT / A) 70F for front-wheel drive and a transaxle (RT / A) 70R for rear-wheel drive. The vehicle is also equipped with an F-PCU 72F and an R-PCU 72R as PCUs (power control units) for supplying power to the FT / A 70F and the RT / A 70R, respectively. The vehicle is also provided with an ESU (Electricity Supply Unit) with a function of charging the battery, and the like.

[0048] Each of the FT / A70F and the RT / A70R is provided with a motor, etc. Each of the F-PCU72F and the R-PCU72R includes a DC-DC converter that converts battery power into power for driving the motor, and the ESU74 includes an AC-DC converter for charging the battery and a DC-D converter for stepping down the voltage, etc. For this reason, in the vehicle, heat is generated in each of the FT / A70F, the RT / A70R, the F-PCU72F, the R-PCU72R, and the ESU74.

[0049] Here, the air conditioning system 10 is provided with a cooling function for the devices of the power train system and the like, and the air conditioning system 10 has a water circulation circuit 14 that provides a cooling function for the power train system.

[0050] The water circulation circuit 14 is provided with a water pump (W / P) 76 in addition to the W / P 52, and the W / Ps 52 and 76 operate in cooperation to circulate water in the water circulation circuit 14. Also, in the water circulation circuit 14, an ESU 74, an F-PCU 72F, an R-PCU 72R, an FO / C (oil cooler) 78F for the FT / A 70F, and an RO / C 78R for the RT / A 70R are arranged in this order downstream of the W / P 76.

[0051] In the water circulation circuit 14, water is circulated through the ESU 74, the F-PCU 72F, the R-PCU 72R, the FO / C 78F, and the RO / C 78R by operating the W / Ps 52 and 76. As a result, in the water circulation circuit 14, each of the ESU 74, the F-PCU 72F, the R-PCU 72R, the FO / C 78F, and the RO / C 78R is cooled.

[0052] Moreover, an EOP (electric oil pump) 80F is disposed between the FT / A70F and the FO / C78F, and an EOP80R is disposed between the RT / A70R and the RO / C78R. In the FO / C80F, the EOP80F is operated to circulate cooling oil between the FT / A70F and the FO / C80F, and heat is exchanged between the cooling oil. In the RO / C80R, the EOP80R is operated to circulate cooling oil between the RT / A70R and the FO / C80F, and heat is exchanged between the cooling oil. As a result, in the powertrain system of the vehicle, the FT / A70F and the RT / A70R are cooled by the water circulated in the water circulation circuit 14.

[0053] The control unit 60 controls the flow rate of water circulated in the water circulation circuit 14 and the opening and closing (opening degree) of the grill shutter 56 according to the cooling capacity required by the powertrain system. At this time, when the control unit 60 determines that a large cooling capacity is required because the temperature of the powertrain system is rising, it performs control such as increasing the flow rate of water and increasing the opening degree of the grill shutter 56 so that the temperature of the circulated water decreases. In the air conditioning system 10, the water circulation circuit 14 has a cooling function for the powertrain system, but may also have a cooling function for the battery.

[0054] Next, the operation of this embodiment will be described. In the air conditioning system 10, when cooling the vehicle cabin, the evaporator 38 is cooled by the refrigerant circulating through the refrigerant circuit 16, and the air passing through the evaporator 38 in the air conditioning unit is cooled to generate conditioned air for cooling the vehicle cabin.

[0055] At this time, in the water circulation circuit 14 of the air conditioning system 10, the water is cooled by the refrigerant circulating in the refrigerant circuit 16 in the chiller 40, and the water can be cooled by the air passing through the radiator 50. As a result, in the air conditioning system 10, the water circulating in the water circulation circuit 14 cools the devices of the powertrain system.

[0056] On the other hand, in the air conditioning system 10, the water circulating through the radiator 50 is used when heating the vehicle interior. In the air conditioning system 10, the cooling capacity in the refrigerant circuit 16 is reduced, so that the water flowing through the water circulation circuit 12 absorbs heat from the refrigerant passing through the water-cooled condenser 24. Also, in the air conditioning system 10, the refrigerant in the refrigerant circuit 16 can absorb heat from the water in the water circulation circuit 14 in the chiller 40, and the water in the water circulation circuit 14 can absorb heat from the outside air in the radiator 50.

[0057] That is, in the air conditioning system 10, the water circulation circuit 12, the water circulation circuit 14, and the refrigerant circuit 16 are thermally connected. Therefore, during heating in the air conditioning system 10, the temperature of the water flowing into the heater core 20 in the water circulation circuit 12 changes in the same manner as the temperature of the water that has passed through the radiator 50 of the water circulation circuit 14 (for example, the water flowing into the heater core 20 and the water that has passed through the radiator 50 have approximately the same temperature).

[0058] As a result, the air conditioning system 10 can heat the vehicle interior using water that absorbs heat from the outside air. During heating, the air conditioning system 10 controls the opening and closing of the grill shutter 56 used to absorb heat from the outside air, thereby improving the energy efficiency of the vehicle.

[0059] The opening and closing control of the grill shutter 56 during heating will now be described. The control unit 60 of the air conditioning system 10 uses the outside air temperature Ta detected by the outside air temperature sensor 62 and the water temperature Tw detected by the water temperature sensor 26 to control the opening and closing of the grill shutter 56 during heating. The control unit 60 opens the grill shutter 56 when the water temperature Tw is lower than the outside air temperature Ta.

[0060] Furthermore, when opening the grill shutter 56 during heating, the control unit 60 uses the temperature difference Td (Td=Ta-Tw) between the water temperature Tw and the outside air temperature Ta to set the opening degree of the grill opening by the grill shutter 56 (the opening degree of the grill shutter 56). Furthermore, when opening the grill shutter 56 during heating, the control unit 60 uses the vehicle speed V to set the opening degree of the grill shutter 56.

[0061] When the control unit 60 sets the opening degree of the grill shutter 56 according to the temperature difference Td, the larger the temperature difference Td, the larger the opening degree of the grill shutter 56 is set. Also, in the control unit 60, when setting (adjusting the opening degree) the opening degree of the grill shutter 56 according to the vehicle speed V, the higher the vehicle speed V, the smaller the opening degree is set.

[0062] That is, the control unit 60 increases the opening degree of the grill shutter 56 as the outside air temperature Ta is higher, and decreases the opening degree of the grill shutter 56 as the outside air temperature Ta is lower. Also, the control unit 60 decreases the opening degree of the grill shutter 56 as the vehicle speed V is higher, and increases the opening degree of the grill shutter 56 as the vehicle speed V is lower. Note that in the present embodiment, descriptions such as "the larger the temperature difference Td" include meanings such as "as the temperature difference Td increases" and "when the temperature difference Td is large, compared with the case when it is small".

[0063] In FIG. 2A, the opening and closing state of the grill shutter 56 with respect to the temperature difference Td is shown in a diagram, and in FIG. 2B, the change in the opening degree of the grill shutter 56 with respect to the vehicle speed V (km / h) and the outside air temperature Ta (°C) is shown in a diagram.

[0064] As shown in FIG. 2A, in the air conditioning system 10 (control unit 60), the opening degree of the grill shutter 56 is set according to the temperature difference Td. At this time, the set temperatures t0, t1, t2, t3 of the temperature difference Td are such that t0 < t1 < t2 < t3. The set temperatures t0, t1, t2, t3 apply values determined based on the heat absorption efficiency and the like among the water circulation circuits 12, 14, the refrigerant circuit 16, and the grill shutter 56 in the air conditioning system 10. Also, for the set temperature t0, a value that can be regarded as the outside air temperature Ta and the water temperature Tw being substantially equal (ideally Ta ≒ Tw) is applied, and for the set temperature t0, a temperature that can be regarded as the heat obtained by absorbing heat from the outside air temperature Ta not affecting the rise in the water temperature on the inlet side of the heater core 20 is applied.

[0065] In the air conditioning system 10, when the temperature difference Td decreases and reaches the set temperature t0, the grill shutter 56 is fully closed (opening degree 0%), and in the air conditioning system 10, when the temperature difference Td becomes t0 or less (Td ≦ t0), the grill shutter 56 is closed. Also, in the air conditioning system 10, when the outside air temperature Ta becomes higher than the water temperature Tw or the like, the temperature difference Td becomes large (increases) and reaches the set temperature t3, the grill shutter 56 is fully opened (opening degree 100%), and in the air conditioning system 10, when the temperature difference Td becomes t3 or more (Td ≧ t3), the grill shutter 56 is fully opened.

[0066] In the control unit 60, within the range where the temperature difference Td is equal to or higher than the set temperature t0 and equal to or lower than the set temperature t3 (t0 ≦ Td ≦ t3) (or it may be the range from the set temperature t0 to the set temperature t3 (t0 < Td < t3)), the opening degree of the grill shutter 56 (the opening degree within the range from fully open to fully closed) is set according to the outside air temperature Ta and the vehicle speed V. Note that in the air conditioning system 10, hysteresis is provided when the grill shutter 56 is opened from fully closed and when it is closed from fully open.

[0067] That is, as shown in FIG. 2B, in the air conditioning system 10, the opening degree of the grill shutter 56 is set and adjusted using the vehicle speed V and the outside air temperature Ta. Note that the numerical values of the scales on the vertical axis and the horizontal axis in FIG. 2B are shown as an example, and the notations "large", "medium", and "small" in FIG. 2B indicate relative opening degrees.

[0068] In the air conditioning system 10, in adjusting the opening degree of the grill shutter 56, the lower the outside air temperature Ta, the smaller the opening degree (the higher the outside air temperature Ta, the larger the opening degree). Also, in the air conditioning system 10, in adjusting the opening degree of the grill shutter 56, the lower the vehicle speed V, the larger the opening degree (the higher the vehicle speed V, the smaller the opening degree).

[0069] In the air conditioning system 10, FIGS. 2A and 2B are stored as maps in the control unit 60, and the opening and closing control of the grill shutter 56 is performed based on these maps. FIG. 3 shows an outline of the opening and closing control of the grill shutter 56 in a flowchart.

[0070] The flowchart of FIG. 3 is repeatedly executed at a predetermined time interval in the control unit 60 on the condition that the opening and closing control of the grill shutter 56 using factors other than heating is not performed during heating.

[0071] Therefore, in the control unit 60 (air conditioning system 10), it is confirmed in the first step 100 whether or not heating operation is in progress, and in step 102, it is confirmed whether or not the grill shutter 56 is in a non-controlled state (non-controlled state, for example, a closed state).

[0072] Here, if the air conditioning system 10 is in a state other than the heating operation (during cooling, during dehumidification, during stop), the control unit 60 makes a negative determination in step 100. Also, even during heating (positive determination in step 100), if the opening and closing control of the grill shutter 56 is being performed due to other factors (the grill shutter 56 is not in the closed state), the control unit 60 makes a negative determination in step 102. When the control unit 60 makes a negative determination in step 100 or step 102, the process ends.

[0073] On the other hand, when heating operation is in progress and the control of the grill shutter 56 is not being performed (the grill shutter 56 is in a closable state), the control unit 60 makes a positive determination in each of steps 100 and 102 and moves to step 104. The control unit 60 detects the outside air temperature Ta and the water temperature Tw on the inlet side of the radiator 50 in step 104, and determines the temperature difference Td between the outside air temperature Ta and the water temperature Tw.

[0074] The determination of the temperature difference Td is made in step 106 as to whether or not the temperature difference Td exceeds the set temperature t0 (Td>t0), and in step 108 as to whether or not the temperature difference Td has not reached the set temperature t3 (Td<t3).

[0075] When the temperature difference Td is less than or equal to the set temperature t0 (Td ≦ t0), the control unit 60 makes a negative determination in step 106 and proceeds to step 110, where it sets the grill shutter 56 to fully closed. Also, when the temperature difference Td is greater than or equal to the set temperature t3 (Td ≧ t3), the control unit 60 makes a negative determination in step 108 and proceeds to step 112, where it sets the grill shutter 56 to fully open.

[0076] On the other hand, when the temperature difference Td exceeds the set temperature t0 and is less than the set temperature t3 (t0 < Td < t3), the control unit 60 makes an affirmative determination in each of steps 106 and 108 and proceeds to step 114. In step 114, the control unit 60 detects the vehicle speed V.

[0077] Thereafter, in step 116, the control unit 60 sets the opening degree of the grill shutter 56 according to the temperature difference Td, the outside air temperature Ta, and the vehicle speed V. A map shown in FIG. 2B is used for this setting of the opening degree.

[0078] In this way, when any one of the opening degree (step 116), fully closed (step 110), or fully open (step 112) is set for the grill shutter 56, the control unit 60 performs opening / closing control of the grill shutter 56 so as to obtain the set opening degree (step 118).

[0079] Here, FIGS. 4A to 4D show the simulation results of the power consumption (driving power + air conditioning power) (W) with respect to the opening degree of the grille shutter 56, the vehicle speed V, and the outside air temperature Ta in the assumed required vehicle. In the simulation, the vehicle speed V (km / h) is set to four levels of vehicle speeds V0, V1, V2, V3 (where V0 < V1 < V2 < V3), and the outside air temperature Ta (°C) is set to two levels of temperatures T1, -T2 (where -T2 < 0 < T1, and the absolute values of T1 and T2 may be the same or different). Also, in each of FIGS. 4A to 4D, when the outside air temperature Ta is at each of the temperatures T1 (°C) and -T2 (°C), FIG. 4A shows the vehicle speed V = V0 (km / h), FIG. 4B shows the vehicle speed V = V1 (km / h), FIG. 4C shows the vehicle speed V = V2 (km / h), and FIG. 4D shows the vehicle speed V = V3 (km / h).

[0080] Also, in the simulation, for the opening degree of the grille shutter 56, two opening degrees O H (%) and O L (%) are set, and for each of the opening degrees O H and O L , the vehicle speed V and the outside air temperature Ta are changed. The opening degree O H and the opening degree O L are set wider than the opening degree O H compared to the opening degree O L (0 ≦ O L < O H ≦ 100). For example, the opening degree O H is set to an angle that is fully open or nearly fully open, and the opening degree O L is set to be close to fully closed. In FIGS. 4A to 4D, the opening degree O H of the grille shutter 56 is shown by a solid line, and the opening degree O L is shown by a dashed line. Further, in the simulation, a fan shroud and a cooling fan are used, and the horizontal axis in the drawing shows the duty ratio (Duty) D when driving the cooling fan. In the simulation, the duty ratio D ranges from 0 (%) to a required value (duty ratio) Ds (%) (where 0 < Ds < 100).

[0081] 4A to 4C, the sum of the driving power and the air conditioning power (driving power + air conditioning power) shown on the vertical axis is shown as a relative value, and power W1(w) to power W 15 (w) is 0 <W1<W2<W3<W4<W5<W6<W7<W8<W9<W 10 <W 11 <W 12 <W 13 <W 14 <W 15 It is as follows.

[0082] As shown in FIG. 4A to FIG. 4D, when the vehicle speed V is V0 and the outside air temperature Ta is T1, when the vehicle speed V is V0 and the outside air temperature Ta is −T2, and when the vehicle speed V is V1 and the outside air temperature Ta is T1, the opening degree of the grill shutter 56 is O. L (%) than the opening O H That is, the power consumed under the above condition is suppressed by the fact that the opening degree of the grill shutter 56 is large, compared to when the opening degree is small.

[0083] In contrast, when the vehicle speed V is V1 (km / h), the outside air temperature Ta is −T2 (° C.), the vehicle speed V is V2 (km / h), and the vehicle speed V is V3 (km / h), the opening degree of the grill shutter 56 is O H Opening degree O L That is, the power consumed under the above conditions is suppressed because the opening degree of the grill shutter 56 is small, compared to when the opening degree is large.

[0084] From these evaluation results, in order to reduce power consumption, it is preferable to increase the opening degree of the grill shutter 56 as the outside air temperature Ta increases, and it is preferable to decrease the opening degree of the grill shutter 56 as the vehicle speed V increases.

[0085] FIG. 5 shows the reduced energy (reduced energy) (w) with respect to the vehicle speed V based on the evaluation results of FIGS. 4A to 4D. That is, FIG. 5 shows the reduced energy (w) with respect to the vehicle speed V, which is determined by changing the opening degree of the grill shutter 56 from the opening degree O to the opening degree V according to the vehicle speed V. H Opening degree O L(or opening degree O H Opening degree O L ), resulting in a reduction in air conditioning power and a reduction in driving power due to reduced air resistance. Note that Fig. 5 shows a case where the outside air temperature Ta is temperature T1 (see dashed line) and a case where the outside air temperature Ta is temperature -T2 (see solid line). That is, Fig. 5 shows a case where the outside air temperature Ta is temperature T1 with a dashed line, and a case where the outside air temperature Ta is temperature -T2, which is lower than temperature T1, with a solid line.

[0086] As shown in FIG. 5, as the vehicle speed V increases, the opening degree of the grill shutter 56 is increased to an opening degree O. H Opening degree O L In this case, the reduced energy is 0 when the opening degree of the grill shutter 56 is 0. H (An opening degree close to the conventional operation of opening the grill shutter 56) is an advantageous point, and this state is shown to continue. Therefore, in the air conditioning system 10, the energy saving effect is greater when the outside air temperature Ta is low than when the outside air temperature Ta is high.

[0087] In this way, in a vehicle, the grill shutter 56 that opens and closes the grill opening is installed, and the air resistance changes and the consumed energy (driving power) changes depending on whether the grill shutter 56 is opened or closed. In this case, when the grill shutter 56 is opened, the vehicle consumes more power to run than when it is closed.

[0088] When the vehicle is heated using the heater core 20, the heat from the outside air can be used to reduce the air conditioning power. In this case, it is necessary to open the grill shutter 56 to introduce outside air into the radiator 50, which increases the driving power. In the air conditioning system 10, the driving power and the air conditioning power can be reduced by appropriately controlling the opening degree of the grill shutter 56 (including the opening degree from fully open to fully closed).

[0089] Here, the air conditioning system 10 uses the outside air temperature Ta and the water temperature Tw at the radiator 50 to determine whether to open the grill shutter 56, and if it is determined that heat cannot be absorbed from the outside air, that is, if the temperature difference Td between the outside air temperature Ta and the water temperature Tw (Td=Ta-Tw) is below the set temperature t0 (Td≦t0≒0), the grill shutter 56 is closed.

[0090] This allows effective heat absorption from the outside air, and the lower the water temperature Tw is relative to the outside air temperature Ta (the higher the outside air temperature Ta is relative to the water temperature Tw and the larger the temperature difference Td is), the greater the heat absorption effect, making it possible to effectively utilize heat.In addition, it is possible to prevent increases in both the air conditioning power and the driving power caused by opening the grill shutter 56 even though there is no heat absorption effect from the outside air.

[0091] In addition, in the air conditioning system 10, when the grill shutter 56 is opened based on the temperature difference Td, it is set according to the outside air temperature Ta and the vehicle speed V. When the outside air temperature Ta is high, a greater heat absorption effect is obtained compared to when the outside air temperature Ta is low, and the higher the outside air temperature Ta, the greater the heat absorption effect is obtained.

[0092] Therefore, in the air conditioning system 10, when the outside air temperature Ta is high, the opening degree of the grill shutter 56 is increased compared to when the outside air temperature Ta is low, and when the outside air temperature Ta is low, the opening degree of the grill shutter 56 is decreased compared to when the outside air temperature Ta is high. In other words, in the air conditioning system 10, the higher the outside air temperature Ta, the larger the opening degree of the grill shutter 56 is, and the lower the outside air temperature Ta, the smaller the opening degree of the grill shutter 56 is. In this way, the air conditioning system 10 can suppress an increase in running power while suppressing air conditioning power.

[0093] Furthermore, when the vehicle speed V is high, the amount of air introduced is greater than when the vehicle speed V is low, which increases the amount of heat absorbed, but also increases the air resistance. For this reason, in the air conditioning system 10, when the vehicle speed V is high, the opening degree of the grill shutter 56 is made smaller than when the vehicle speed V is low, and when the vehicle speed V is low, the opening degree of the grill shutter 56 is made larger than when the vehicle speed V is high. This allows the air conditioning system 10 to suppress an increase in air conditioning power while suppressing an increase in running power.

[0094] Furthermore, the effective opening degree of the grill shutter 56 is affected by the outside air temperature Ta and the vehicle speed V. Therefore, in the air conditioning system 10, when opening the grill shutter 56, the opening degree of the grill shutter 56 is set in accordance with the outside air temperature Ta and the vehicle speed V. This allows the air conditioning system 10 to effectively set the opening degree of the grill shutter 56.

[0095] In addition, in the air conditioning system 10, when the grill shutter 56 is opened, it opens when the temperature difference Td reaches the set temperature t1 (hysteresis is provided). As a result, in the air conditioning system 10, the increase in air resistance caused by opening the grill shutter 56 when the heat absorption effect from the outside air is low can be suppressed, and the increase in running power can be suppressed.

[0096] Furthermore, in the air conditioning system 10, the water circulation circuit 14 in which the radiator 50 is provided has a cooling function for the powertrain system. Therefore, in the air conditioning system 10, heat can be absorbed from the water that has cooled the powertrain system, so that it is possible to prevent the grill shutter 56 from being opened unnecessarily or to prevent the grill shutter 56 from being opened to a large degree.

[0097] In this embodiment, the heater core 20 is arranged in the water circulation circuit 12, and the radiator 50 is arranged in the water circulation circuit 14, and the water circulation circuits 12 and 14 are thermally connected by the refrigerant circuit 16. However, as long as the heat medium circulated in the outside air heat absorption part absorbs heat from the outside air, and the heat medium circulated in the heater core absorbs heat from this heat medium, the outside air heat absorption part and the heater core may be arranged in a circulation circuit in which the same heat medium is circulated. Also, the heat medium circulation circuit in which the outside air heat absorption part is provided and the heat medium circulation circuit in which the heater core is provided may be thermally connected.

[0098] [Modifications] Next, a modification of this embodiment will be described. 6 shows a heat medium circulation circuit as a schematic configuration of a main part of an air conditioning system 90 as a vehicle air conditioning system according to a modified example, and in the modified example, a heat medium circulation circuit provided with an outside air heat absorption section and a heat medium circulation circuit provided with a heater core are thermally connected. Note that in the modified example, the same functional parts as those in the above embodiment (air conditioning system 10) are given the same reference numerals and their description is omitted.

[0099] 6, the air conditioning system 90 includes a water circulation circuit 12 and a refrigerant circuit 92 in which a refrigerant is used as a heat medium. The air conditioning system 90 differs from the air conditioning system 10 in that the water circulation circuit 14 is omitted and the refrigerant circuit 92 is provided instead of the refrigerant circuit 16. The air conditioning system 90 also includes a control unit 94 having the same function as the control unit 60 in air conditioning.

[0100] The refrigerant circuit 92 has a general configuration in which a refrigeration cycle is formed by a refrigerant, and includes a compressor 36, a water-cooled condenser 24, an electric (motorized) expansion valve 34C, an outdoor condenser 96 as an outdoor air heat absorption unit, an expansion valve 34B, and an evaporator 38. In addition, a refrigerant temperature sensor 98 is disposed in the refrigerant circuit 92 as a first temperature detection unit for detecting the temperature of the refrigerant flowing into the outdoor condenser 96 (the refrigerant before heat exchange with the outdoor air).

[0101] In the refrigerant circuit 92, the compressor 22 is rotated and driven to circulate the refrigerant through the water-cooled condenser 24, the expansion valve 34C, the outdoor condenser 96, the expansion valve 34A, and the evaporator 38 in this order.

[0102] On the other hand, in the air conditioning system 90, the exterior condenser 96 is disposed at the front of the vehicle, and the exterior condenser 96 faces the grill shutter 56. As a result, in the air conditioning system 10, when the grill shutter 56 is opened, heat exchange occurs in the exterior condenser 96 between the outside air introduced from the grill opening depending on the opening degree of the grill shutter 56 and the vehicle speed, and the refrigerant in the refrigerant circuit 92.

[0103] In this air conditioning system 90, during cooling operation, air is cooled by the evaporator 38 of the refrigerant circuit 92 to generate conditioned air for cooling.

[0104] In addition, in the air conditioning system 90, during heating operation, the control unit 94 controls the opening and closing of the grill shutter 56 in accordance with the outside air temperature Ta, the refrigerant temperature Tr detected by the refrigerant temperature sensor 98, the vehicle speed V, etc. In the air conditioning system 90, during heating operation, the temperature of the refrigerant (refrigerant temperature Tr) circulating through the refrigerant circuit 92 and flowing into the outdoor condenser 96 is higher than the outside air temperature Ta, so that the grill shutter 56 is fully closed. As a result, in the air conditioning system 90, water from the water circulation circuit 12 that has absorbed heat from the refrigerant via the water-cooled condenser 24 is used to generate conditioned air for heating.

[0105] On the other hand, when the refrigerant temperature Tr is lower than the outside air temperature Ta and the heat obtained by absorbing heat from the outside air temperature Ta is a temperature that affects the rise in the water temperature on the inlet side of the heater core 20, the control unit 94 controls to open the grill shutter 56. In addition, the control unit 94 controls the opening degree of the grill shutter 56 in accordance with the outside air temperature Ta, the temperature difference (temperature difference Td) between the outside air temperature Ta and the refrigerant temperature Tr, and the vehicle speed V.

[0106] At this time, the control unit 94 increases the opening degree of the grill shutter 56 as the temperature difference between the refrigerant temperature Tr and the outside air temperature Ta increases, and decreases the opening degree of the grill shutter 56 as the temperature difference decreases. Also, the control unit 94 decreases the opening degree of the grill shutter 56 as the outside air temperature Ta decreases, and increases the opening degree of the grill shutter 56 as the outside air temperature Ta increases. Furthermore, the control unit 94 decreases the opening degree of the grill shutter 56 as the vehicle speed V increases, and increases the opening degree of the grill shutter 56 as the vehicle speed V decreases.

[0107] As a result, the air conditioning system 90 can achieve the same effects as the air conditioning system 10 during heating operation.

[0108] That is, when it is determined that the air conditioning system 90 cannot absorb heat from the outside air, the grill shutters 56 are closed to prevent air resistance from increasing and thereby prevent an increase in running power.

[0109] Also, in the air conditioning system 90, when the outside air temperature Ta is high, the opening degree of the grill shutter 56 is increased compared to when the outside air temperature Ta is low, and when the outside air temperature Ta is low, the opening degree of the grill shutter 56 is decreased compared to when the outside air temperature Ta is high. This allows the air conditioning system 90 to suppress an increase in driving power while suppressing air conditioning power.

[0110] Furthermore, in the air conditioning system 90, when the vehicle speed V is high, the opening degree of the grill shutter 56 is made smaller than when the vehicle speed V is low, and when the vehicle speed V is low, the opening degree of the grill shutter 56 is made larger than when the vehicle speed V is high. This allows the air conditioning system 90 to suppress an increase in air conditioning power while suppressing an increase in traveling power. [Explanation of symbols]

[0111] 10, 90 Air conditioning system (vehicle air conditioning system) 12, 14 Water circulation circuit 16, 92 Refrigerant circuit 20 Heater core 24 Water-cooled condenser 38 Evaporator 40 Chiller 50 Radiator (outside air heat absorption part) 54 Water temperature sensor (first temperature detection part) 56 Grill Shutter 58 Finn 60, 94 Control section 62 Outside air temperature sensor (second temperature detection unit) 64 Vehicle speed sensor (vehicle speed detection section) 96 Outdoor condenser (outdoor air heat absorption part) 98 Refrigerant temperature sensor (first temperature detection part)

Claims

1. a heater core that performs heat exchange between a heat medium circulated during a heating operation in the vehicle cabin and the conditioned air when generating conditioned air for conditioning the vehicle cabin; an outside air heat absorption section that absorbs heat into a heat medium circulated from outside air by introducing the outside air into the heater core; a grill shutter that is arranged to be able to open and close a grill opening that is open toward the front of the vehicle and that allows outside air in front of the vehicle to be introduced into the outside air heat absorption section by opening the grill opening; a first temperature detection means for detecting a first temperature as a temperature of the heat medium input to the outside air heat absorption portion; A second temperature detection means for detecting a second temperature as a temperature of the outside air introduced into the outside air heat absorbing portion; a control unit that controls the grill shutter to open the grill opening when the first temperature is lower than the second temperature during heating of the vehicle interior; 2. A vehicle air conditioning system comprising:

2. The vehicle air conditioning system according to claim 1 , wherein the control unit controls the grill shutter to open the grill opening to a larger degree as a temperature difference between the first temperature and the second temperature increases.

3. The vehicle air conditioning system according to claim 2 , wherein the control unit reduces an opening degree of the grill opening caused by the grill shutter as the second temperature decreases.

4. Further comprising a vehicle speed detection means for detecting a vehicle speed, The vehicle air conditioning system according to claim 1 , wherein the control unit controls the grill shutter to open the grill opening to a larger degree as the vehicle speed increases.

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