VEHICLE AIR-CONDITIONING SYSTEM AND OPERATING METHOD

Abstract

A vehicle may include an electric drive having at least one electric motor, at least one battery and at least one power electronic and may be cooled via a cooling circuit. The vehicle may include an air-conditioning system including at least one duct. A refrigeration circuit and a thermoelectric heating device may be arranged in the at least one duct. A control device may be configured/programmed to actuate the air-conditioning system, and may be operable to: activate the refrigeration circuit to cool the interior; operate the thermoelectric heating device as a cooler during a start-up phase of the refrigeration circuit; operate the thermoelectric heating device only as the cooler during the start-up phase of the refrigeration circuit when a cool-down function is activated; and automatically activate the cool-down function when a temperature difference between an actual temperature of the interior and a target temperature of the interior exceeds a predetermined temperature difference threshold value.

Claims

1. A vehicle comprising: a vehicle interior; an electric drive for driving the vehicle, the electric drive including at least one electric motor, at least one battery and at least one power electronic, the electric drive cooled via a cooling circuit, the cooling circuit configured to circulate a coolant and including a heat exchanger; a vehicle air-conditioning system including: at least one duct for directing an air flow to the vehicle interior; a refrigeration circuit configured to circulate a refrigerant and including an evaporator, the refrigeration circuit arranged in the at least one duct for cooling the air flow; a thermoelectric heating device arranged in the at least one duct for heating the air flow; a control device configured to operate the vehicle air-conditioning system coupled to the refrigeration circuit and to the thermoelectric heating device; the control device at least one of configured and programmed to actuate the vehicle air-conditioning system, wherein the control device is operable to: activate the refrigeration circuit to cool the vehicle interior; operate the thermoelectric heating device as a cooler during a start-up phase of the refrigeration circuit, the thermoelectric heating device extracting heat from the air flow; operate the thermoelectric heating device only as the cooler during the start-up phase of the refrigeration circuit when a cool-down function is activated; and automatically activate the cool-down function when a temperature difference between an actual temperature of the vehicle interior and a target temperature of the vehicle interior exceeds a predetermined temperature difference threshold value; wherein the heat exchanger of the cooling circuit is arranged in the at least one duct of the vehicle air-conditioning system and is a component of the thermoelectric heating device of the vehicle air-conditioning system.

2. The vehicle according to claim 1, wherein the thermoelectric heating device includes at least one thermoelectric element configured to convert an electric current into a thermal flow.

3. The vehicle according to claim 1, wherein the thermoelectric heating device includes the heat exchanger integrated into the cooling circuit where the coolant to cool at least one vehicle component.

4. The vehicle according to claim 2, wherein the at least one thermoelectric element is integrated into the heat exchanger.

5. The vehicle according to claim 1, wherein the evaporator and the thermoelectric heating device are arranged in a shared housing.

6. The vehicle according to claim 1, wherein the control device is further operable to deactivate the thermoelectric heating device during a cooling operation phase of the refrigeration circuit, following the start-up phase, or the thermoelectric heating device operates to deliver heat to the air flow.

7. The vehicle according to claim 1, wherein the control device is further operable to: operate the thermoelectric heating device as the cooler until a cooling capacity of the refrigeration circuit reaches a predetermined performance threshold value, and end operation of the thermoelectric heating device as the cooler when the cooling capacity of the refrigeration circuit reaches the performance threshold value.

8. The vehicle according to claim 1, wherein the control device is further operable to: operate the thermoelectric heating device with direct current, wherein the thermoelectric heating device is configured for heating via supplying the direct current with a first polarity, and is configured as the cooler when the direct current is supplied with a second polarity, inverse to the first polarity.

9. The vehicle according to claim 1, wherein the operating method further comprises deactivating the thermoelectric heating device during a cooling operation phase of the refrigeration circuit, following the start-up phase.

10. The vehicle according to claim 1, wherein the operating method further comprises operating the thermoelectric heating device to deliver heat to the air flow.

11. The vehicle according to claim 1, wherein the cooling circuit is coupled to the electric motor, the battery, and the power electronics in a heat-transmitting matter.

12. The vehicle according to claim 1, wherein the cooling circuit further includes a coolant pump configured to drive the coolant in the cooling circuit.

13. The vehicle according to claim 1, wherein the air-conditioning system further comprises a condenser.

14. The vehicle according to claim 1, wherein the air-conditioning system further comprises a refrigerant pump.

15. The vehicle according to claim 1, wherein the air-conditioning system further comprises a fan configured to drive the air flow.

16. The vehicle according to claim 15, wherein the fan is disposed in the shared housing.

17. The vehicle according to claim 1, wherein the thermoelectric heating device is arranged downstream of the evaporator with respect to the air flow.

18. The vehicle according to claim 1, wherein the control device is coupled to one other power electronic configured to operate the thermoelectric heating device.

19. The vehicle according to claim 18, wherein the one other power electronic is integrated into the control device.

20. A vehicle comprising: a vehicle interior; an electric drive for driving the vehicle, the electric drive including at least one electric motor, at least one battery and at least one power electronic, the electric drive cooled via a cooling circuit, the cooling circuit configured to circulate a coolant and including a heat exchanger; a vehicle air-conditioning system including: at least one duct for directing an air flow to the vehicle interior; a refrigeration circuit configured to circulate a refrigerant and including an evaporator, the refrigeration circuit arranged in the at least one duct for cooling the air flow; a thermoelectric heating device arranged in the at least one duct for heating the air flow; a control device configured to operate the vehicle air-conditioning system coupled to the refrigeration circuit and to the thermoelectric heating device; the control device at least one of configured and programmed to actuate the vehicle air-conditioning system, wherein the control device is operable to: activate the refrigeration circuit to cool the vehicle interior; operate the thermoelectric heating device as a cooler during a start-up phase of the refrigeration circuit, the thermoelectric heating device extracting heat from the air flow; operate the thermoelectric heating device only as the cooler during the start-up phase of the refrigeration circuit when a cool-down function is activated; and automatically activate the cool-down function when a temperature difference between an actual temperature of the vehicle interior and a target temperature of the vehicle interior exceeds a predetermined temperature difference threshold value; wherein the heat exchanger of the cooling circuit is arranged in the at least one duct of the vehicle air-conditioning system and is a component of the thermoelectric heating device of the vehicle air-conditioning system; and wherein the evaporator and the thermoelectric heating device are arranged in a shared housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The FIGURE shows a schematic diagram in the manner of a circuit diagram of a vehicle which is equipped with a vehicle air-conditioning system.

DETAILED DESCRIPTION

[0030] According to the FIGURE, a vehicle 1 comprises a vehicle interior 2 and a vehicle air-conditioning system 3 for air-conditioning the vehicle interior 2, and an electric drive 4. The vehicle 1 can be configured here as an electric vehicle, which has only this electric drive 4 for driving the vehicle 1. Likewise, the vehicle 1 can be configured as a hybrid vehicle, which has the electric drive 4 in addition to an internal combustion engine, which is not shown here, for driving the vehicle 1. Likewise, a hybrid vehicle is conceivable, in which an internal combustion engine comes into use as a so-called range extender, in order to provide electric current for operating the electric drive 4, so that the drive of the vehicle takes place by the electric drive and not by the internal combustion engine.

[0031] The vehicle 1 is in addition equipped with a cooling circuit 5, which serves for cooling the electric drive 4. In the example, the electric drive 4 has at least one electric motor 6, at least one battery 7 and an item of power electronics 8, which controls an electrical supply of the electric motor 6 with electric power from the battery 7. Likewise, the power electronics 8 can control a charging of the battery 7 during a generator operation of the electric motor 6.

[0032] The cooling circuit 5 is likewise coupled to a component of the electric drive 4 in a heat-transmitting manner, in order to bring about a cooling of the respective component. In the example of FIG. 1, the cooling circuit 5 is coupled to all three components which are shown, therefore to the electric motor 6, to the battery 7 and to the power electronics 8, in a heat-transmitting manner. A coolant circulates in the cooling circuit 5. In addition, the cooling circuit 5 contains a heat exchanger 9 and a coolant pump 10 for driving the coolant in the cooling circuit 5.

[0033] The vehicle air-conditioning system 3, which can also be designated below in abbreviated form as air-conditioning system 3, comprises at least one duct 11 for directing an air flow 12, indicated by an arrow, to the vehicle interior 2. In addition, the air-conditioning system 3 is equipped with a refrigeration circuit 13, in which a refrigerant circulates, which circuit has an evaporator 14, a condenser 15 and a refrigerant pump 16. The evaporator 14 is arranged in the duct 11 and serves for cooling the air flow 12. The condenser 15 directs the heat, extracted from the air flow 12, to an environment 17 of the vehicle 1.

[0034] The air-conditioning system 3 comprises in addition a thermoelectric heating device 18, which is likewise arranged in the duct 11 and is expediently arranged here downstream of the evaporator 14 with respect to the air flow 12. The heating device 18 serves for heating the air flow 12. In addition, the air-conditioning system 3 is equipped with a fan 19, which drives the air flow 12. For example, air can be drawn in from the environment 17 by means of the fan 19.

[0035] In the example of FIG. 1, the air-conditioning system 3 has a shared housing 20 for the heating device 18, the evaporator 14 and the fan 19.

[0036] Furthermore, the air-conditioning system 3 is equipped with a control device 21, which serves to operate the air-conditioning system 3 and which, for this, is coupled in a suitable manner to all controllable components of the air-conditioning system 3. Control lines 22, via which the control device 21 is connected to the heating device 18, the coolant pump 10, the refrigerant pump 16 and the fan 19, are indicated in FIG. 1. The control device 21 is coupled, in addition, to a further item of power electronics 23, which serves for operating the heating device 18. In the example of FIG. 1, this item of power electronics 23 is integrated into the control device 21.

[0037] It is clear that the control device 21 is basically coupled to further components of the air-conditioning system 3, such as for example to a temperature sensor system, not shown here, which can measure for example the current actual temperature of the vehicle interior 2. In particular, thereby also a current temperature difference between the actual temperature and target temperature of the vehicle interior 2 can be determined.

[0038] The heating device 18 has at least one thermoelectric element 24, which is configured as a Peltier element and which accordingly converts an electric current into a thermal flow. Usually, the heating device 18 contains a plurality of such thermoelectric elements 24.

[0039] In addition, in the example the heat exchanger 9 of the cooling circuit 5 is likewise integrated into the duct 11 of the air-conditioning system 3, and namely downstream of the evaporator 14. According to the particularly advantageous embodiment which is shown here, this heat exchanger 9 forms a component of the heating device 18, such that the respective thermoelectric element 24 is integrated into the heat exchanger 9. In this way, on the one hand by means of the cooling circuit 5 the air flow 12 can be heated. On the other hand, by means of the respective thermoelectric element 24, heat can either be transferred from the air flow 12 to the coolant or from the coolant to the air flow 12.

[0040] In the case of a cold start of the vehicle 1, it can be necessary to cool the vehicle interior 2 down to a comfortable temperature as rapidly as possible. For this, a cool-down function can be initiated or respectively activated either by the respective vehicle occupant manually or via the control device 21 automatically. This includes on the one hand an activating of the refrigeration circuit 13 and on the other hand an operating of the heating device 18 as cooler during a start-up phase of the refrigeration circuit 13. In other words, the heating device 18, provided per se for heating, is used as a cooler during the start-up phase of the refrigeration circuit 13. During this start-up phase, the thermodynamic equilibrium which occurs in the refrigeration circuit 13 in the deactivated state, must be shifted in order to start the thermodynamic circuit process, which during a cooling operating phase of the refrigeration circuit 13 enables an efficient heat absorption through the respective phase change of the refrigerant in the evaporator 14, and enables an efficient heat emission in the condenser 15. During this start-up phase of the refrigeration circuit 13, however, no appreciable cooling of the air flow 12, perceptible by the vehicle occupants in the vehicle interior 2, is possible. To increase the comfort, the heating device 18 is actuated by the control device 21 as a cooler during the cool-down operation. This takes place for example through a corresponding current feed of the respective thermoelectric element 24. For example, the heating device 18 or respectively the respective thermoelectric element 24 is supplied with direct current for operating as heating with a first polarity, whereas the heating device 18 or respectively the respective thermoelectric element 24 for operating as a cooler is supplied with a second polarity with direct current, which is contrary to the first polarity, therefore is inverse. In so far as the cool-down function is thus activated, during the start-up phase of the refrigeration circuit 13 the air flow 12 is cooled by means of the heating device 18, which is operated as a cooler, for this, by the control device 18. As this cool-down function is carried out in particular at a cold start of the vehicle 1, generally no cooling requirement is yet present for the electric drive 4, so that a heat emission into the coolant of the cooling circuit 5 is possible. In particular therefore also the cooling circuit 5 can be used for cooling the air flow 12.

[0041] As soon as the refrigeration circuit 13 leaves its start-up phase and reaches its cooling operation phase, the heating device 18 is deactivated by the control device 21. As soon as the refrigeration circuit 13 has reached its nominal operating phase and the cool-down function is deactivated, the heating device 18 can be operated as heating by means of the control device 21 to realize a re-heat function. However, as soon as sufficient waste heat occurs in the electric drive 4, this re-heat function can also be realized via the cooling circuit 5 therefore in connection with the heat exchanger 9, so that the respective thermoelectric element 24 can be deactivated.

[0042] For example, the heating device 18 can be operated as a cooler until a cooling capacity of the refrigeration circuit 13 reaches a predetermined performance threshold value. When this performance threshold value is then reached, a deactivation of the heating device 18 takes place, therefore a deactivation of the cooling function of the heating device 18.

[0043] The cool-down function can be deactivated manually by the vehicle occupant. It can also be deactivated in a time-controlled manner. Likewise, it is conceivable to deactivate the cool-down function in a temperature-controlled manner, for example provision can be made to deactivate the cool-down function as soon as the temperature difference between actual temperature and target temperature in the vehicle interior 2 is less than 5 C.

[0044] Basically, it is conceivable to design the control device 21 so that on each putting into operation of the refrigeration circuit 13, the heating device 18 is operated as a cooler during the start-up phase. However, a more favourable embodiment with regard to energy is preferred, in which on activating of the refrigeration circuit 13 during the start-up phase the heating device 18 is only operated as a cooler when the above-mentioned cool-down function is activated. This can be activated for example automatically by the control device 21, when a temperature difference is present between the current actual temperature of the vehicle interior 2 and the target temperature of the interior 2 desired by the vehicle driver, which temperature difference is greater than a predetermined temperature difference which can be, for example, 10 C.