Vehicle air conditioning device

Abstract

This invention provides an air conditioning device for vehicles that optimizes power consumption in the heating system. In external gas mode, external gas from the external gas inlet (10b) is introduced into the ventilation duct (10); in internal gas mode, internal gas from the internal gas inlet (10a) is introduced into the ventilation duct (10); and in mixed internal and external gas mode, both external gas from the external gas inlet (10b) and internal gas from the internal gas inlet (10a) are introduced into the ventilation duct. When heating the vehicle interior in either internal gas mode or mixed internal and external gas mode, the control unit (70) ensures that all air blown from the outlet passes through the heater core (40), and sets the temperature of the heat transfer medium in the heating system based on the temperature of the air passing through the evaporator (20).

Description

Technical Field

[0001] This disclosure relates to air conditioning systems for vehicles that use heaters. Background Technology

[0002] Previously, gasoline engine vehicles and hybrid vehicles utilized the waste heat of the engine for heating. However, in electric vehicles and hybrid vehicles that also operate as electric vehicles, the waste heat of the engine cannot be utilized. Therefore, heat pumps, which are used in refrigeration and other similar applications, are used to provide heating by absorbing heat from the outside air and using the heat generated by the heater. Patent Document 1 describes a heating method using a heat pump.

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2010-143533 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] Here, when using heaters, the heating temperature of the heater is set relatively high, similar to the case of using engine waste heat, and the blowing temperature is controlled by controlling the amount of heat exchange here.

[0008] However, heat sources such as heaters use battery power. Therefore, when this utilization is inefficient, the cost per mile increases and the driving range is shortened.

[0009] In this invention, a vehicle air conditioning device that can effectively utilize a heater is provided.

[0010] Methods for solving problems

[0011] The vehicle air conditioning device disclosed herein comprises: a heat pump system that circulates a heat medium in an evaporator and a condenser; a heating system that circulates a heat medium in a heater and a heater core; a ventilation duct that houses the evaporator and the heater core and has an outlet that blows air introduced from an inlet formed on one side to the other side; and a control unit that controls the temperature of the heat medium in the heating system. The inlets include an external gas inlet for introducing air from outside the vehicle and an internal gas inlet for introducing internal gas from inside the vehicle. In an external gas mode, the external gas is introduced... External gas is introduced into the ventilation duct at the inlet. In internal gas mode, internal gas from the internal gas inlet is introduced into the ventilation duct. In internal and external gas mixing mode, both external gas from the external gas inlet and internal gas from the internal gas inlet are introduced into the ventilation duct. When heating is provided in internal gas mode or internal and external gas mixing mode, the control unit ensures that all air blown out from the outlet passes through the heater core and sets the temperature of the heat medium in the heating system based on the temperature of the air that has passed through the evaporator.

[0012] Invention Effects

[0013] According to the vehicle air conditioning device disclosed herein, the temperature of the heating system heat medium is set according to the internal gas temperature, thereby enabling the power consumption of the heater in the heating system to be appropriate and enabling the vehicle's driving range to be extended. Attached Figure Description

[0014] Figure 1 This is a schematic diagram illustrating the structure of an example of a vehicle air conditioning unit according to an embodiment.

[0015] Figure 2 This is a graph showing the relationship between the target blowout temperature TAO and the target water temperature TWO.

[0016] Figure 3 This is a flowchart illustrating the process of setting the target water temperature TWO2 in this embodiment.

[0017] Figure 4 It is a diagram showing the flow state of the external and internal gases in a two-layer flow mode.

[0018] Figure 5 This is a concept diagram of a two-layer mode in a vehicle. Detailed Implementation

[0019] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be noted that the following embodiments do not limit the present disclosure, and structures formed by selectively combining multiple examples are also included in the present disclosure.

[0020] Figure 1 This diagram schematically illustrates the structure of an example of a vehicle air conditioning unit according to an embodiment. The ventilation duct 10 has an internal gas inlet 10a and an external gas inlet 10b. The internal gas inlet 10a introduces air from the vehicle interior, drawing in internal gas through openings located at the front and rear of the vehicle interior. The external gas inlet 10b introduces external air (atmosphere) from outside the vehicle, typically through an opening located at the front of the vehicle.

[0021] A blower 12 is installed inside the internal gas inlet 10a and the external gas inlet 10b of the ventilation duct 10. This blower 12 has a fan 12b driven by an electric motor (M) 12a, and the rotation of the fan 12b introduces air (internal and external gas) from the internal gas inlet 10a and the external gas inlet 10b. A damper 14 is installed inside the internal gas inlet 10a and the external gas inlet 10b, adjusting the opening degree of the two inlets. Depending on the position of the damper 14, the opening can be adjusted from 100% internal gas (0% external gas) to 0% internal gas (100% external gas). It should be noted that the blower 12 and the damper 14 can also be installed separately for internal gas and for external gas, and can be controlled independently.

[0022] An evaporator 20 is disposed downstream of the blower 12 within the ventilation duct 10. A compressor (C) 22, a condenser 24, and a pressure reducing valve 26 are connected to the evaporator 20 to form a circulation path. A heat pump system is constructed by circulating a heat transfer medium within this circulation path. It should be noted that this heat pump system extracts heat from the air within the ventilation duct 10 by vaporizing the heat transfer medium in the evaporator 20, and releases this heat to the outside through the condenser 24 to cool the room. However, as described in Patent Document 1, by providing a second condenser or similar means, the heat released by the heat pump system can also be used for heating. Furthermore, during heating, the compressor 22 can be stopped, or the pressure reducing valve 26 can be opened, and the evaporator 20 can be set to room temperature (internal gas temperature). The air temperature after passing through the evaporator 20 is measured by a sensor 28. It should be noted that the air temperature measured by the sensor 28 can be considered as the indoor temperature (internal gas temperature).

[0023] An air mixing damper 30 is disposed downstream of the evaporator 20. This air mixing damper 30 is movable from an upper closed position to a lower closed position. A heater core 40 is disposed in the upper passage downstream of the air mixing damper 30. When the air mixing damper 30 is in the lower closed position, 100% of the air flowing in the ventilation duct 10 bypasses the heater core 40. When the air mixing damper 30 is in the upper closed position, 100% of the air flowing in the ventilation duct 10 passes through the heater core 40.

[0024] A heating system is formed by connecting a pump (WP) 42 and a heater 44 to the heater core 40, creating a circulation path. In this example, water circulates as the heat medium in this circulation path. The heater 44 is, for example, an electric heater, which heats the circulating water. It should be noted that the temperature of the circulating water is measured by a water temperature sensor (T) 46. Furthermore, a condenser of a heat pump system can be installed in place of or parallel to the heater 44, and the circulating water can be heated by this heat pump system.

[0025] Downstream of the heater core 40 are three air outlets: a foot-side air outlet 50, an occupant-side air outlet 52, and a defrost-side air outlet 54. The foot-side air outlet 50 blows air from inside the ventilation duct 10 toward the feet of the occupants in the driver's and passenger's seats. The occupant-side air outlet 52 blows air toward the upper body of the occupants in the driver's and passenger's seats. The defrost-side air outlet 54 blows air upward from below the inside of the windshield.

[0026] Furthermore, a foot-side damper 56 is provided at the foot-side air outlet 50, an occupant-side damper 58 is provided at the occupant-side air outlet 52, and a defrost-side damper 60 is provided at the defrost-side air outlet 54, enabling control over the airflow from the ventilation duct 10. In this example, the foot-side damper 56, the occupant-side damper 58, and the defrost-side damper 60 are controlled to open and close via a drive unit 62.

[0027] The control unit 70 controls the opening and closing of the damper 14, the air mixing damper 30, the three dampers on the exhaust side, and the heating of the heater 44. Temperature data is supplied to the control unit 70 from an internal gas sensor (T) 72 located near the internal gas inlet 10a, an external gas sensor (T) 74 located near the external gas inlet 10b, and a water temperature sensor 46 located on the water circulation path to the heater core 40. Furthermore, a sunlight sensor 76, which measures the intensity of sunlight entering the vehicle interior, is located near the windshield, and its detection value is also supplied to the control unit 70. A control panel 80, which accepts occupant input, is provided for switching between the vehicle interior temperature setting, external gas mode, internal gas mode, and internal / external gas mixing mode, as well as the selection of the exhaust outlet, and the resulting operation signals are supplied to the control unit 70. The control unit 70 can be configured as a processor that processes the input data and outputs control signals.

[0028] Regarding the introduction of internal and external gases, the internal gas mode is when the external gas inlet 10b is fully closed and the internal gas inlet 10a is fully open through the damper 14 (damper 14: position indicated by the dashed line). The external gas mode is when the external gas inlet 10b is fully open and the internal gas inlet 10a is fully closed through the damper 14 (damper 14: position shown in sand). The middle mode is the mixing mode of internal and external gases.

[0029] Temperature control

[0030] In addition to the set temperature (set value), external gas / internal gas mode settings, and outlet selection set in the control panel 80, the control unit 70 also controls the damper 14, air mixing damper 30, heater 44, etc., based on the detection values ​​of the various sensors mentioned above.

[0031] <Target blowing temperature TAO>

[0032] The control unit 70 calculates the target blowing temperature TAO based on the indoor temperature (internal gas temperature) TR, the set temperature (set value) TSET of the internal gas temperature, and the detection values ​​of the various sensors mentioned above.

[0033] TAO=E×(TSET+ΔT)-F×TR-G×TAM-H×TS+C

[0034] Here, TSET is the set temperature, TR is the indoor temperature (corresponding to the internal gas temperature), TAM is the external gas temperature, TS is the solar radiation, ΔT and C are correction constants, and E, F, and H are coefficients.

[0035] Various corrections, such as multiplication by a coefficient, were performed. However, the target blowing temperature is set to the temperature obtained by subtracting the external gas temperature TAM and the indoor temperature TR from the set temperature TSET. In other words, the higher the set temperature TSET, the higher the target blowing temperature, and the higher the external gas temperature TAM and the indoor temperature TR, the lower the target blowing temperature.

[0036] It should be noted that the airflow outlet is determined by the settings on the control panel 80. Furthermore, regarding the airflow, if it has also been set on the control panel 80, that airflow will be used. However, if the airflow is set automatically, it can be determined based on the required heating volume of the room; for example, the higher the TAO (heat level), the larger the airflow will be.

[0037] The target blowing temperature (TAO) can also be determined not by mathematical formulas, but by using tables or other methods.

[0038] MAXHOT (Maximum Heating Capacity)

[0039] Regarding necessary heating, if the available heat supply is insufficient, the control unit 70 determines that it is in a MAXHOT state and sets the air mixing damper 30 to allow all air to pass through the heater core 40.

[0040] <Target water temperature setting for both>

[0041] The target water temperature TWO of the heat transfer medium (water) circulating in the heater core 40 is determined based on the target outlet temperature TAO. That is, considering the heat exchange efficiency of the heater core 40 and the heat loss through the pipe leading to the outlet, the target outlet temperature TAO is set slightly higher than TAO by adding a predetermined value. For example... Figure 2 As shown, before the target blowing temperature TAO = 30℃, the target water temperature TWO = 50℃ is kept constant, then a one-to-one correspondence is made before 70℃, and then it is kept constant at 90℃.

[0042] Thus, the target water temperature TWO is determined by a predetermined addition based on the target blow-out temperature (20°C in the above case). Here, the air mixing damper 30 is present, which can mix air that has not passed through the heater core 40, and there are many cases where engine waste heat can be utilized; therefore, the target water temperature TWO is set relatively high. In this example, the external gas temperature is set to 5°C, and the indoor temperature is also set to the same temperature, and heat loss is calculated. The external gas temperature can be an actual measured temperature, but it can also be fixed to a general temperature (e.g., 5°C).

[0043] <Correcting the target water temperature TWO2 setting>

[0044] As described above, the target water temperature TWO is set with a constant relationship to the target blowout temperature TAO. The air flowing into the heater core 40 is the air that has passed through the evaporator 20 and is at the same temperature as room temperature. Furthermore, as described above, the amount of air passing through the heater core 40 is controlled by the air mixing damper 30.

[0045] Therefore, in this embodiment, when the required air volume and other conditions are such that all air passes through the heater core 40, the control unit 70 is set to the MAXHOT state.

[0046] Therefore, by using the air mixing damper 30 to completely close the upper passage, all air is introduced into the heater core 40.

[0047] Furthermore, for the target water temperature TWO, correction is made based on the actual indoor temperature, i.e., the air temperature after passing through the evaporator 20 as measured by sensor 28 (which can be considered to be the same as the internal gas temperature).

[0048] For example, with TAO = 50°C, TWO = 70°C. Then, the target water temperature TWO2 = 60°C is calculated by subtracting the difference between Te (internal gas temperature, 15°C) and TAM (external gas temperature, 5°C) from the obtained TWO = 70°C.

[0049] TWO2=TWO(70)-(Te(15)-TAM(5))=60

[0050] Therefore, relative to the target water temperature TWO = 70℃, the internal gas temperature is reduced to obtain a corrected target water temperature TWO2 = 60℃.

[0051] Here, TWO is the temperature under the premise that air that has not passed through the heater core 40 is properly introduced through the air mixing damper 30. TWO2 is the temperature at which all air passes through the heater core 40, and there is no change regarding the outlet temperature TAO = 50°C.

[0052] Therefore, through this embodiment, the water temperature (heat medium temperature) of the heat medium (water) circulating in the heater core 40 can be reduced, and the power consumption of the heater 44 can be reduced.

[0053] Thus, by using the corrected target water temperature TWO2, the power required for the aforementioned heating at an external air temperature of 5°C can be reduced by about 40%, thereby increasing the range per charge by about 10%.

[0054] In this embodiment, the introduction of external and internal gases can be adjusted by operating the damper 14. When setting the internal gas rate α under the condition of mixing external and internal gases, it is sufficient that TWO2 (calibrated target water temperature) = TWO (target water temperature) - α(Te (internal gas temperature) - TAM (external gas temperature)). It should be noted that the external gas temperature TAM can be a constant value or an actual measured value.

[0055] <Processing Flow>

[0056] Figure 3 This is a flowchart illustrating the process of setting the target water temperature TWO2 in this embodiment.

[0057] First, determine whether the air conditioner is turned on (S11). If the determination in S11 is yes, determine whether it is MAXHOT (S12). If the determination in S12 is yes, determine whether it is in external gas mode (S13). If the determination in S13 is yes, set the target water temperature TWO2 as the temperature after subtracting the correction value corresponding to the internal gas temperature (internal gas temperature Te - external gas temperature TAM) (S14). If the determinations in S11 to S13 are no, set TWO2 = TWO (S15).

[0058] Therefore, by ensuring that all the air in the pipe passes through the heater core 40, the target water temperature TWO is corrected to the corrected target water temperature TWO2, which can maintain and keep the blow-out temperature at a relatively low temperature.

[0059] <Air Mixing Damper>

[0060] The operation of the air mixing damper 30 will be explained. The air mixing damper 30 controls the amount of air passing through the heater core 40. As mentioned above, the target water temperature TWO is set to a relatively high value. Therefore, in order to obtain the target blow-out temperature TAO, the proportion of air passing through the heater core 40 is controlled by the air mixing damper 30, thereby obtaining the desired target blow-out temperature TAO.

[0061] For example, the ratio AM of air passing through heater core 40 can be determined by AM = (TAO-Te) / (TWO-Te) based on the target blowout temperature TAO and the internal gas temperature Te.

[0062] <Dual-layer circulation mode>

[0063] Figure 4This diagram illustrates the flow state of the external and internal gases in a dual-flow pattern. In this example, the duct is separated into an upper and lower layer by a partition 90. Here, the blower 12 includes a fan 12b-1 for the internal gas and a fan 12b-2 for the external gas, and both can be driven independently. It also has an outlet 92 pointing towards the rear seat side.

[0064] It should be noted that the diagram omits details such as the dampers for the internal and external gas inlets and outlets, and the air mixing damper 30, showing a state where the internal and external gases are completely separated and circulated. Figure 4 In the structure, dampers and other devices can be provided to mix the air in the upper and lower layers, thereby enabling the mixing mode of internal and external gases, and the heater core 40 can also heat the introduced external gas.

[0065] In the dual-flow mode, as shown in the figure, heating using the above-mentioned corrected target water temperature TWO2 can be carried out when the external gas is blown into the room without passing through the heater core 40, or when a portion of the external gas is introduced into the lower layer and all the air in the lower layer passes through the heater core 40.

[0066] Figure 5 This is a concept diagram of the dual-mode system in vehicle 100. External air flows in the upper part of the vehicle interior, while internal air circulates in the lower part of the vehicle interior.

[0067] Explanation of reference numerals in the attached figures

[0068] 10 Ventilation duct, 10a Internal gas inlet, 10b External gas inlet, 12 Blower, 14 Damper, 20 Evaporator, 22 Compressor, 24 Condenser, 26 Pressure reducing valve, 28 Sensor, 30 Air mixing damper, 40 Heater core, 44 Heater, 46 Water temperature sensor, 50 Foot side air outlet, 52 Occupant side air outlet, 54 Defrost side air outlet, 56 Foot side damper, 58 Occupant side damper, 60 Defrost side damper, 62 Drive unit, 70 Control unit, 72 Internal gas sensor, 74 External gas sensor, 76 Sunlight sensor, 80 Control panel, 90 Partition, 92 Air outlet, 100 Vehicle.

Claims

1. A vehicle air conditioning unit, comprising: A heat pump system circulates the heat transfer medium between the evaporator and the condenser; The heating system circulates the heat medium in the heater and heater core; A ventilation duct, equipped with the evaporator and the heater core, has an outlet for blowing air introduced from an inlet formed on one side to the other side; and The control unit controls the temperature of the heat medium in the heating system. The inlet includes an external gas inlet for introducing air from outside the vehicle and an internal gas inlet for introducing internal gas from inside the vehicle. In external gas mode, external gas from the external gas inlet is introduced into the ventilation duct; in internal gas mode, internal gas from the internal gas inlet is introduced into the ventilation duct; in internal and external gas mixing mode, both external gas from the external gas inlet and internal gas from the internal gas inlet are introduced into the ventilation duct. When heating is being provided to the vehicle interior in either internal gas mode or a mixed internal and external gas mode, the control unit ensures that all air blown from the outlet passes through the heater core, and sets the temperature of the heat transfer medium in the heating system based on the temperature of the internal gas, taking the temperature of the air passing through the evaporator as the temperature of the internal gas. The control unit sets the first target temperature (TWO) of the heat medium based on the target blowing temperature (TAO) of the air blown out from the outlet, and sets the temperature of the heat medium by subtracting the difference between the temperature of the internal gas (Te) and the temperature of the external gas (TAM) from the first target temperature (TWO) (TWO2 = TWO - (Te - TAM)).

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