Air conditioning system with heating device integrated in floor mat, motor vehicle and method for operating an air conditioning system

Abstract

The invention relates to an air conditioning device for controlling the temperature of a passenger compartment (12) of a motor vehicle, comprising a first heating device (14) which is designed to heat an air flow (16) which can be introduced into the passenger compartment (12). At least one second heating device (36) is arranged in the passenger compartment (12) and is designed to subject an occupant of the passenger compartment (12) to heat radiation (44). A control device (46) of the air conditioning device is designed to operate at least the first heating device (14) depending on an anticipated duration for a distance to be covered by the motor vehicle. The air conditioning device comprises a second heating device (36) which is integrated into a floor mat (38).The second heating device (36) integrated into the floor mat (38) is designed to emit thermal radiation (44) when connected to an electrical energy storage device of the motor vehicle. Furthermore, the invention relates to a motor vehicle with the air conditioning device and a method for operating the air conditioning device.

Description

[0001] The invention relates to an air conditioning system for controlling the temperature of a passenger compartment of a motor vehicle, comprising a first heating system designed to heat an air flow that can be introduced into the passenger compartment. At least one second heating system of the air conditioning system is arranged in the passenger compartment and designed to subject an occupant of the passenger compartment to heat radiation. A control system of the air conditioning system is designed to operate at least the first heating system depending on an anticipated duration for a distance to be traveled by the motor vehicle. Furthermore, the invention relates to a motor vehicle having such an air conditioning system and a method for operating the air conditioning system.

[0002] Particularly in an electric vehicle, sophisticated thermal management of the entire operating system is even more important than in a vehicle with a combustion engine. This is because if too much electrical energy is lost due to warming or heating the passenger compartment, or if a lot of electrical energy is required to cool the vehicle's electrical components, this electrical energy is not available to propel the vehicle. The electrical energy extracted from an electrical energy storage device in the form of a traction battery in the vehicle thus results in a loss of the vehicle's range. Intelligent thermal management that uses electrical energy efficiently accordingly enables a longer range of the vehicle in electric mode.

[0003] In an electric vehicle, the demand for electrical energy to heat the passenger compartment or passenger cell is particularly high in winter. Furthermore, a user of the vehicle may set a target temperature for the air in the passenger compartment to a comparatively high value, such as 23°C or more. This may be due to the user striving to achieve a comfortable air temperature in the footwell of the passenger cell as well. However, since warm air rises, the footwell tends to be colder than the upper area of ​​the passenger compartment or passenger cell. Warm feet, however, are crucial for the perception of warmth of vehicle occupants.

[0004] The goal of achieving a pleasantly warm temperature in the passenger compartment footwell can also be detrimental if a warm air stream is directed toward the upper area of ​​the passenger compartment, especially the windows, to keep them free of fogging. In addition, air is a poor conductor of heat.

[0005] DE 10 2014 210 736 A1 describes an air conditioning device for a motor vehicle, which comprises a primary air conditioning element in the form of a convective heater. Cool fresh air is drawn in and fed to an air-water heat exchanger connected to a cooling circuit of an internal combustion engine of the motor vehicle. The heated air is blown into the interior through air outlets distributed throughout the motor vehicle. This primary heater has a long latency period. The air conditioning device also comprises personal air conditioning elements in the form of an infrared radiator, a seat heater, and a steering wheel heater. During an estimated driving time, only those air conditioning elements whose latency period is no greater than the estimated driving time are included in the climate control.

[0006] DE 10 2011 101 011 A1 describes an electric underfloor heating system for a motor vehicle. The underfloor heating system comprises a surface heating element that can be electrically connected to a power supply source present on the motor vehicle. The underfloor heating system can be designed as a floor mat that can be detachably arranged on the floor of the motor vehicle and has fastening elements for attaching the floor mat to the floor. Two of the fastening elements can be connected as a pair of connecting elements to establish the electrical connection to a positive pole and a negative pole of the motor vehicle's power supply source.

[0007] The object of the present invention is to provide an air conditioning device of the type mentioned at the outset which enables particularly energy-efficient temperature control of the passenger compartment, as well as to provide a motor vehicle with such an air conditioning device and a corresponding method for operating the air conditioning device.

[0008] This object is achieved by an air conditioning system having the features of patent claim 1, a motor vehicle having the features of patent claim 7, and a method having the features of patent claim 8. Advantageous embodiments with expedient further developments of the invention are specified in the dependent patent claims and in the following description.

[0009] The air conditioning system according to the invention for controlling the temperature of a passenger compartment of a motor vehicle comprises a first heating device. The first heating device is designed to heat an air flow that can be introduced into the passenger compartment. At least one second heating device of the air conditioning system is arranged in the passenger compartment and designed to subject an occupant of the passenger compartment to heat radiation. A control device of the air conditioning system is designed to operate at least the first heating device depending on an expected duration for a distance to be traveled by the motor vehicle. The air conditioning system comprises a second heating device that is integrated into a floor mat.In this case, the second heating device integrated into the floor mat is designed to emit heat radiation when connected to an electrical energy storage device of the motor vehicle.

[0010] This is based on the knowledge that by operating the second heating device integrated into the floor mat, which can in particular be designed like an infrared heating element, the feet of the occupant in the passenger compartment can be warmed very directly. And by operating the second heating device, an unnecessary amount of energy is avoided from being released into the environment. In this way, the occupant's perception of warmth can be significantly increased without the entire air in the passenger compartment having to be heated in a short space of time at great energy expenditure. By operating the second heating device integrated into at least one floor mat, warm feet and a pleasant perception of warmth for the occupants of the passenger compartment can be easily ensured with low overall energy consumption of the air conditioning device. This applies even when the air temperature in the passenger compartment is comparatively low.Consequently, the air conditioning system enables particularly efficient temperature control of the passenger compartment.

[0011] The control device is designed to determine the presence of at least one charging station along the route to be traveled and the charge level of the electrical energy storage device. Depending on the presence and the charge level, it communicates a temperature control strategy to a user of the motor vehicle. If the charging station is not used, the temperature control strategy includes reduced heating of the air flow and operation of the at least one second heating device.

[0012] The user can thus be informed that a temperature control strategy is possible in which a charging stop at the at least one charging station for the purpose of charging the electrical energy storage device is omitted, provided the user is willing to accept reduced heating of the air flow. For the user, this advantageously does not result in a loss of comfort. Operating the at least one second heating device ensures a pleasant feeling of warmth for the user despite the reduced heating of the air flow.

[0013] The suggestion to forgo using the charging station can be communicated to the user, particularly via a human-machine interface of the motor vehicle. For example, such an interface can be used to suggest to the user that they travel the distance without stopping at the charging station by switching to a more efficient air conditioning or temperature control strategy. If the user accepts this suggestion, the distance can be traveled or completed without using the charging station, despite a low charge level of the electrical energy storage device, with reduced airflow heating. This is advantageous for the user.

[0014] The route to be covered can, in particular, lead from a starting point to a destination and back to the starting point. This is particularly advantageous if the starting point offers a convenient, especially private, charging option for the user.

[0015] Additionally or alternatively, the control device is designed to create a respective user profile from the temperature control settings set by a respective user of the motor vehicle and the routes traveled by the user. The control device is designed to consider the user profile for operating the first heating device and / or the at least one second heating device. This is based on the recognition that different users of the motor vehicle may have different preferences regarding the temperature control of the passenger compartment. Furthermore, it can be determined, for example, that certain users regularly travel certain routes in the motor vehicle.By taking this into account, the control system can ensure that the temperature setting typically desired by the respective user is taken into account when traveling the respective route. This allows the individual climate control requirements of each user to be met in a very individual manner.

[0016] In particular, regularly traveled routes such as those to work, shopping, school, or kindergarten, etc., can be easily recognized by the control device, even if the corresponding destinations are not entered into the vehicle's navigation system. For example, workplaces, shopping facilities, or facilities such as schools or kindergartens can be included in map data used by the vehicle's navigation system. This allows such routes to be determined by the control device and assigned to an identified user. Furthermore, by incorporating the user's preferred temperature settings into the user profile, the air conditioning requirements of the respective user for such routes can be met very easily and conveniently.

[0017] Recognition or identification of the respective user can be achieved, for example, using a key used by the user to unlock and / or start the motor vehicle and / or by entering identification information and / or through facial recognition or the like. The successful recognition or identification of the respective user can be communicated to the control device.

[0018] In particular, the user profile can be stored independently of the vehicle and transferred to the respective vehicle, for example, when purchasing a new vehicle and / or using a car-sharing service. This provides a particularly high level of convenience for the user.

[0019] The second heating device integrated into the floor mat, especially when configured as an infrared heating element, emits heat very directly and quickly to the body in the form of thermal radiation. This eliminates the need to heat the entire air in the footwell or foot area of ​​the passenger compartment, which is energy-intensive, to keep the occupant's feet warm. This is advantageous.

[0020] Another advantage is that an existing air conditioning system in a motor vehicle can be easily expanded or retrofitted by additionally using the second heating unit integrated into the floor mat. This allows for expanded air conditioning functionality and offers the possibility of improving a temperature control or heating strategy with regard to the vehicle's range and energy consumption.

[0021] If an existing motor vehicle is additionally equipped or retrofitted with at least one floor mat into which the second heating device is integrated, the energy consumption for air conditioning the passenger compartment can be effectively reduced, particularly in winter or at low ambient temperatures. Furthermore, it is very easy to ensure that the occupants of the passenger compartment always have warm feet. Floor mats into which the second heating device is integrated can also be easily removed from the passenger compartment in summer or at warm or hot ambient temperatures and replaced with non-heated floor mats. This contributes to a high degree of flexibility of the air conditioning system. Furthermore, the floor mat having the second heating device can advantageously be easily replaced in the event of a defect.

[0022] The second heating device can be arranged, in particular, between a top layer facing the passenger compartment and a base layer of the floor mat facing the floor of the passenger compartment. This ensures good protection for the heating device arranged between the top layer and the base layer. The size of the second heating device can be adapted, in particular, to the specific conditions of the motor vehicle. This allows the different sizes of the respective footwells in different motor vehicles to be particularly well accommodated.

[0023] The second heating device integrated into the floor mat can in particular be designed as a flexible heating element which is capable of emitting heat radiation, in particular infrared radiation, during operation.

[0024] Preferably, the second heating device can be connected to a socket present in the motor vehicle by means of a plug-in connector, which can be located, for example, in a center console of the motor vehicle and / or in a rear compartment of the motor vehicle. The second heating device can be designed, in particular, for operation with a voltage of 12 volts.

[0025] Preferably, the control device is designed to initially operate the at least one second heating device and subsequently, in response to the expected time for the distance to be covered exceeding a threshold value, additionally operate the first heating device. This is based on the knowledge that on long journeys and, consequently, an expected longer time for covering the distance, a pleasant feeling of warmth can be provided for the occupant very quickly by means of the second heating device integrated into the floor mat. This applies in particular if at least one further second heating device of the air conditioning system is designed as a seat heater and / or as a steering wheel heater and / or as a heated knob of a gearshift of the motor vehicle.Such contact heaters, as well as the second heating device integrated into the floor mat, can provide the occupant with a pleasant feeling of warmth.

[0026] If the first heating device is subsequently additionally operated, this can, in particular, result in a comparatively slow increase in the air temperature in the passenger compartment. This is accompanied by significantly lower energy consumption of the air conditioning system than would be the case with a rapid heating of the air in the passenger compartment by heating the air flow that can be introduced into the passenger compartment by means of the first heating device. Consequently, such an operating mode is conducive to energy-efficient temperature control of the passenger compartment of the motor vehicle.

[0027] Preferably, the control device is designed to detect a target temperature of the air in the passenger compartment set by a user of the motor vehicle and, by operating the first heating device, to heat the air flow, which leads to an actual air temperature that is lower than the target temperature. The control device is designed to operate the at least one second heating device depending on the actual temperature. This is based on the knowledge that a user who sets a specific target temperature as their comfortable temperature can be offered the same level of thermal comfort if the air in the passenger compartment is heated to the lower actual temperature but the at least one second heating device is also operated.Setting a higher target air temperature by the user can be driven by the user's motivation to have a pleasantly high air temperature, particularly in the foot area of ​​the passenger compartment. However, a pleasant feeling of warmth in the area of ​​the user's or passengers' feet can be provided very easily by operating the second heating device integrated into the floor mat. Therefore, it is not necessary to heat the entire air in the passenger compartment to the high target temperature that the user has only set in order to have warm feet. Consequently, it is beneficial for energy-efficient temperature control of the passenger compartment if, by operating the first heating device, the air in the passenger compartment is only heated to the actual temperature, which is lower than the set target temperature, with at least one second heating device also being operated.

[0028] In particular, it may be the case that the user sets a temperature of, for example, 22°C to 23°C as the target temperature for the air in the passenger compartment. In this case, by operating the first heating device, the air flow may be heated, for example, resulting in an actual air temperature in the passenger compartment of only approximately 19°C to 20°C and thus an actual temperature that is lower than the target temperature. However, this does not result in a loss of comfort for the user because the second heating device, which emits at least one heat radiation, is still operating. This advantageously allows significant energy savings to be achieved in the operation of the air conditioning system.

[0029] Preferably, the control device is designed to operate at least one additional second heating device, which is arranged on another vehicle seat of the motor vehicle and / or on a boundary wall of the passenger compartment, depending on the distance to be traveled and the occupancy of a vehicle seat of the motor vehicle. Thus, a high level of thermal comfort can be achieved for the occupant for whom the occupancy of the vehicle seat is detected by operating the at least one additional second heating device.

[0030] For example, the control device can detect that a short trip, for example to a kindergarten or school, is pending, using a child seat arranged on the vehicle seat. A pleasant feeling of warmth can then be achieved for a child in the child seat by operating the at least one additional second heating device. For example, if a vehicle seat in a rear row of seats of the motor vehicle is occupied by the child seat, an additional second heating device can be operated, which is located on a backrest of the additional vehicle seat, for example in the form of a front seat of the motor vehicle.

[0031] The additional second heating device arranged on the perimeter wall of the passenger compartment can be designed, for example, as an infrared radiator mounted on a ceiling or roof lining of the vehicle. This allows comfortable heating conditions to be created, particularly for children seated in a child seat in a second or third row of seats. However, for a short journey, for example, to kindergarten or school, the air in the entire passenger compartment does not need to be heated by the first heating device. This is advantageous for the energy-efficient operation of the air conditioning system.

[0032] It's very easy to determine that a short trip, for example to kindergarten or school, is imminent. For example, the vehicle user can enter a destination into the vehicle's navigation system on the first trip to kindergarten or school. Once the user knows the route and no longer uses the navigation system, it's still very easy to determine that the same route will be taken at the same time on a particular weekday. If the vehicle seat occupancy is also detected, a high level of thermal comfort can be provided for the vehicle seat occupant very easily by operating at least one second heating device.

[0033] The vehicle seat can also be used by a child or another passenger other than the driver of the motor vehicle without the use of a child seat. If the vehicle seat also has seat heating, the seat heating of the occupied vehicle seat can be additionally activated as the at least one additional second heating device by the control device controlling the seat heating.

[0034] This also contributes to the high level of thermal comfort for the vehicle seat occupant.

[0035] Preferably, the control device is designed to maintain a temperature of the air in the passenger compartment during use of a charging station designed to charge the electrical energy storage device, depending on weather data and / or an expected time duration for covering a remaining section of the route.

[0036] This is based on the realization that, following charging of the electrical energy storage device at the charging station, the occupant's stay in the passenger compartment is expected to be shorter, even if the remaining portion of the journey is short. This can be taken into account by the control device in the temperature control strategy. This is because, particularly for a short stay in the passenger compartment, not all of the air in the passenger compartment needs to be heated or kept warm. Rather, by operating at least one second heating device during the short stay in the passenger compartment, a pleasant feeling of warmth can be provided for the user.

[0037] Depending on weather data and / or the expected length of the remaining section of the journey, the control device can decide whether or not it is advisable to maintain the temperature of the air in the passenger compartment in view of the energy requirements for operating the air conditioning system.

[0038] Furthermore, depending on the duration of use of the charging station and, for example, the outside temperature, it may be more advantageous in terms of energy consumption to at least substantially maintain the air temperature in the passenger compartment or to reheat it when the user re-enters the passenger compartment of the motor vehicle. Therefore, it is advantageous if the control device decides, depending on the weather data and the time required to travel the remaining portion of the journey, whether to maintain the air temperature in the passenger compartment or to allow the air temperature in the passenger compartment to drop. This is beneficial for energy-efficient operation of the air conditioning system.

[0039] The first heating device can be provided by a heat exchanger of a refrigerant circuit of the air conditioning system. For example, compressed refrigerant can be supplied to the heat exchanger by means of a compressor of the refrigerant circuit, which is then cooled at the heat exchanger by the air flow introduced into the passenger compartment absorbing heat from the refrigerant. In this case, heat pump operation of the refrigerant circuit can be realized, in particular.

[0040] Additionally or alternatively, the first heating device can be provided by a radiator through which a coolant flows, wherein the radiator is integrated into a coolant circuit of the air conditioning system. In this case, waste heat generated during charging of the electrical energy storage device can be supplied to the radiator via the coolant.

[0041] This is based on the realization that, particularly when charging at a high-power charging station (i.e., a so-called high-power charger, HPC), a particularly large amount of lost heat or waste heat is generated during the charging process. This waste heat can be advantageously used to heat or keep the passenger compartment warm. This is particularly useful in cold weather conditions and the user intends to subsequently travel a longer distance.

[0042] For example, a charging device for charging the electrical energy storage device and / or the electrical energy storage device itself can be integrated into the coolant circuit to utilize the waste heat generated during charging, particularly during rapid charging, and transfer it to the airflow via the radiator. This allows the charging process to simultaneously be used to condition or precondition the passenger compartment. This is advantageous.

[0043] Preferably, the control device is designed to detect a number of occupants in the passenger compartment and, depending on the number, to at least temporarily prevent the operation of the first heating device and to cause the operation of the at least one second heating device. This is based on the knowledge that a larger number of occupants in the passenger compartment results in the air in the passenger compartment heating up during the journey solely through the occupants' body heat. However, particularly at the start of the journey, a pleasant feeling of warmth for the occupants can be ensured very quickly by operating the at least one second heating device. This is advantageous for the energy-efficient operation of the air conditioning system.

[0044] If, as the journey continues with a larger number of passengers, cold fresh air is introduced into the passenger compartment, the control device can, in particular, cause the first heating device to operate in order to heat this cold fresh air.

[0045] The motor vehicle according to the invention has an air conditioning system according to the invention. The motor vehicle is preferably designed as an electric vehicle or a hybrid vehicle. Particularly in such a motor vehicle, it is important to use the energy reserves of the electrical energy storage device sparingly with regard to the energy consumption of the air conditioning system and the comfort of the vehicle's occupants.

[0046] If the electrical energy storage device of the motor vehicle is designed as a high-voltage battery, the electrical energy storage device has a nominal voltage of more than 60 volts and in particular of up to several hundred volts.

[0047] In the method according to the invention for operating an air conditioning system designed to regulate the temperature of a passenger compartment of a motor vehicle, a first heating system of the air conditioning system is designed to heat an air flow that can be introduced into the passenger compartment. At least one second heating system of the air conditioning system is arranged in the passenger compartment and exposes an occupant of the passenger compartment to heat radiation. A control system of the air conditioning system operates at least the first heating system depending on an expected duration for a distance to be traveled by the motor vehicle. The air conditioning system comprises a second heating system integrated into a floor mat, wherein the second heating system integrated into the floor mat emits heat radiation when connected to an electrical energy storage device of the motor vehicle.The control device determines the presence of at least one charging station on the route to be traveled and a charge level of the electrical energy storage device. Depending on the presence and the charge level, the control device communicates a temperature control strategy to a user of the motor vehicle. This strategy includes reduced heating of the air flow and operation of the at least one second heating device if the charging station is not used. Additionally or alternatively, the control device creates a respective user profile from temperature control specifications set by a respective user of the motor vehicle and the routes traveled by the user and takes the user profile into account for operating the first heating device and / or the at least one second heating device.

[0048] By operating the second heating device, integrated into the floor mat, the occupant can be provided with a pleasant feeling of warmth in a very energy-efficient manner by exposing the passenger compartment occupant to the heat radiation. This process enables particularly energy-efficient temperature control of the passenger compartment.

[0049] The advantages and preferred embodiments described for the air conditioning device according to the invention apply analogously to the motor vehicle according to the invention and to the method according to the invention and vice versa.

[0050] The invention therefore also includes further developments of the method according to the invention and of the motor vehicle that have features already described in connection with the further developments of the air conditioning system according to the invention. For this reason, the corresponding further developments of the method according to the invention and of the motor vehicle are not described again here.

[0051] The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus.

[0052] The invention also encompasses combinations of the features of the described embodiments. The invention therefore also encompasses implementations that each comprise a combination of the features of several of the described embodiments, unless the embodiments are described as mutually exclusive.

[0053] Exemplary embodiments of the invention are described below. Shown are: Fig. 1 shows a highly schematic view of a passenger compartment of a motor vehicle, wherein an air conditioning device of the motor vehicle comprises a first heating device by means of which an air flow that can be introduced into the passenger compartment can be heated, and wherein the air conditioning device comprises a second heating device that is integrated into a floor mat and that can emit heat radiation during operation; and Fig. 2 schematically shows the passenger compartment according to Fig. 1 motor vehicle.

[0054] The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention that can be considered independently of one another, each of which also develops the invention independently of one another. Therefore, the disclosure is intended to encompass combinations of the features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0055] In the figures, the same reference symbols designate elements with the same function.

[0056] From one in Fig. 2 schematically illustrated motor vehicle 10 is in Fig. 1, a passenger compartment 12 is also shown schematically. An air conditioning device of the motor vehicle 10 comprises a first heating device 14, by means of which an air flow 16 that can be introduced into the passenger compartment 12 can be heated. For example, the first heating device 14 can be arranged in the region of a (in Fig. 1 (not shown) instrument panel of the motor vehicle 10, in particular in a so-called air conditioning box. The air flow 16 can be introduced into the passenger compartment 12 via air vents (also not shown). A fan 18 of the air conditioning system operable for this purpose is Fig. 1 shown schematically.

[0057] Heating the air in the passenger compartment 12 by heating the air flow 16 is associated with a comparatively high energy requirement. This is particularly important when the motor vehicle 10, as in Fig. 2, is designed as an electric vehicle or hybrid vehicle. Here, the motor vehicle 10 has an electrical energy storage device 20, which provides electrical energy for at least one electric drive device 22 of the motor vehicle 10. Wheels 24 of the motor vehicle 10 can preferably be driven by means of the electric drive device 22, which is provided, for example, by at least one electric motor.

[0058] In particular, if the first heating device 14 is designed as an electrical heating device, the heating of the air flow 16 is accompanied by a reduction in the electrical energy stored in the electrical energy storage device 20. Additionally or alternatively, the first heating device 14 can be designed as a heat exchanger of a Fig. 2 schematically shown refrigerant circuit 26 of the air conditioning device.

[0059] The refrigerant circuit 26 can be used in heat pump operation. In heat pump operation, a compressor 30 of the refrigerant circuit 26 supplies compressed and heated refrigerant to the heat exchanger usable as the first heating device 14. The air flow 16 can absorb heat from this heated refrigerant. The refrigerant in the refrigerant circuit 26 can then be expanded by means of an expansion device 32 and fed to an evaporator 34 of the refrigerant circuit 26. At the evaporator 34, the expanded refrigerant can absorb heat, for example, from the bypass air. Such heat pump operation of the refrigerant circuit 26 also requires electrical energy, for example, to operate the compressor 30.

[0060] In order to conserve the electrical energy reserves of the energy storage device 20, at least one second heating device 36 of the air conditioning device can be used, wherein the second heating device 36 in Fig. 1 is shown schematically. Accordingly, the second heating device 36 is integrated into a floor mat 38 on which a passenger (not shown) of the passenger compartment 12 can place his feet when the passenger is sitting on one of the Fig. 1 vehicle seats 40, 42 shown as examples.

[0061] The in Fig. 1 rear vehicle seat 42 assigned floor mat is for reasons of clarity in Fig. 1 are not shown separately. Nor are Fig. 1 further second heating devices are shown, for example, in the form of a seat heater and / or a steering wheel heater. What all of these exemplary second heating devices have in common is that they emit heat radiation 44 during operation, which in Fig. 1 is illustrated by arrows. This heat radiation 44 can very quickly provide the occupant of the passenger compartment 12 located on the respective vehicle seat 40, 42 with a pleasant feeling of warmth, without the need to heat all of the air in the passenger compartment 12 by heating the air flow 16 by means of the first heating device 14. Consequently, the air conditioning system is particularly energy-efficient. This is because the second heating device 36, which is designed in particular as an infrared heating element, emits the heat in the form of heat radiation 44 very directly and quickly to the irradiated body, for example, to the body of the occupant.

[0062] The operation of the first heating device 14 can be carried out by a Fig. 1 schematically shown control device 46 of the air conditioning device. Different types of control can be implemented for operating the at least one second heating device 36. For example, the second heating device 36 can have a mechanical switch by means of which the second heating device 36 can be switched on and off. Additionally or alternatively, it is possible to adjust the heating output of the second heating device 36 in several stages, for example, in three stages.

[0063] Furthermore, the second heating device 36 can have an automatic switch-off function that deactivates the second heating device 36 after a predetermined number of minutes. Additionally or alternatively, the second heating device 36 can be switched off by means of a motion sensor (not shown) that detects that the occupant has moved from the location where the heat radiation 44 can be emitted to the occupant by operating the second heating device 36.

[0064] Control of the heating device 36 may additionally or alternatively be possible via a wireless communication link, for example via Bluetooth and a corresponding application on a smartphone or similar mobile device. In this case, too, it may be provided that the second heating device 36 is automatically switched off when the user is within a certain distance of the second heating device 36, for example, because the user leaves the passenger compartment 12 of the motor vehicle 10.

[0065] Wireless control of the second heating device 36 can additionally or alternatively be implemented via a connection to an infotainment system of the motor vehicle 10, which has corresponding software. For example, the user of the motor vehicle 10 can operate the second heating device 36 via the infotainment system or such a human-machine interface.

[0066] According to the Fig. 1, the second heating device 36 can be connected to an on-board network of the motor vehicle 10, into which the electrical energy storage device 20 (see Fig. 2) is integrated. The control of the second heating device 36 can be implemented via the control device 46. For example, a bus system of the motor vehicle 10 can be used for this purpose, such as a CAN bus (CAN = Controller Area Network) or the like.

[0067] If the control device 46 can control the second heating device 36, a particularly diverse range of possible uses for the second heating device 36 is provided.

[0068] The control device 46, which is designed, for example, as a control unit or a computing unit, can access a navigation system 48 (see Fig. 1) of the motor vehicle 10. Thus, the control device 46 can evaluate previously entered navigation destinations and assign them to various users of the motor vehicle 10. Furthermore, it is advantageous if the control device 46 can access current weather data and weather forecasts for operating the first heating device 14 and / or the second heating device 36. This is advantageous with regard to a fuel-efficient heating strategy.

[0069] If a user of motor vehicle 10 couples a mobile device, such as a smartphone, with a computer of motor vehicle 10 designed for this purpose, access can be gained, in particular, to the respective user's calendar. Preferably, destinations of routes entered in the calendar can be transferred directly to the navigation system 48 of motor vehicle 10. Additionally or alternatively, it is possible to link the user's calendar entries with destinations of respective routes manually entered by the user into the navigation system 48. This information can be very easily fed from the navigation system 48 to the control device 46.

[0070] It is advantageous if the respective air conditioning preferences of the respective user are also recorded. This is because the control device 46 can then take into account a user profile for reaching a destination along the respective route, which preferably includes the temperature control specifications or air conditioning preferences of the respective user. This allows the respective heating devices 14, 36 to be operated depending on the distance to be covered and the respective user's air conditioning preferences, thus achieving high energy efficiency of the air conditioning system.

[0071] In the heating or temperature control strategy to be implemented by the control device 46, the charge level of the electrical energy storage device 20 can be automatically checked before the start of the journey. Furthermore, the distance to be covered can be taken into account with regard to the electrical energy consumption required to cover it, and / or weather data during the journey can be taken into account. This allows a temperature control or air conditioning strategy that takes such parameters into account.

[0072] Additionally, it is possible to precondition the passenger compartment 12 while the motor vehicle 10 is still at its starting location, for example, at a private charging facility or charging station belonging to the user. This reduces the amount of electrical energy required to operate the respective heating devices 14, 36 during the journey.

[0073] During preconditioning, the quality of the air in the passenger compartment 12 can preferably be influenced, for example by filtering out pollen or the like and / or by adding at least one fragrance or the like. This can also be effected by the control device 46, preferably depending on the user profile of the respective user of the motor vehicle 10.

[0074] Depending on a destination entered by the user into the navigation system 48 or on a destination regularly visited by the user, the control device 46 can determine the temperature control strategy, optimize the route with regard to electrical energy consumption, calculate the range of the motor vehicle 10, and a charging strategy for charging the electrical energy storage device 20. Based on this, the control device 46 can derive a target value for the temperature control of the passenger compartment 12 or interior of the motor vehicle 10 and ensure that this target value is achieved.

[0075] In particular, the control device 46 can check in iterative loops whether the air conditioning destination and the associated route can still be linked to the current position of the motor vehicle 10 and the user's air conditioning request. In this case, the control device 46 can ensure that the type of air conditioning of the passenger compartment 12 is adapted to the given situation, particularly taking into account the weather data and the user's air conditioning request. This allows the energy requirement of the heating system or the air conditioning system to be optimized. This is advantageous with regard to a long range of the motor vehicle 10 in electric driving mode.

[0076] For example, the floor mats 38 can be switched on predictively before the start of the journey by operating the second heating devices 36 integrated therein in addition to or alternatively to at least one seat heater and / or one steering wheel heater.

[0077] In a situation illustrating the operation of the air conditioning system, the control device 46 can be informed that there is only one occupant in the passenger compartment 12 of the motor vehicle 10 and that only a comparatively short journey, for example to the occupant's workplace, is being undertaken. The control device 46 can then cause the first heating device 14 not to be activated at all. Rather, the control device 46 can cause only the at least one second heating device 36 to be activated, as well as the seat heating (not shown) and the steering wheel heating (not shown). By omitting the operation of the first heating device 14, by means of which the air flow 16 can be heated, a particularly energy-efficient operation of the air conditioning system can be achieved.

[0078] Additionally or alternatively, the control device 46 can assign the Fig. 1 rear vehicle seat 42, wherein a driver sitting on the front vehicle seat 40 is driving to a kindergarten, school, or the like. In this case, for example, the second heating device 36 of the floor mat 38 assigned to the front vehicle seat 40 and (if present) the seat heating of the front vehicle seat 40 can be operated. If the rear vehicle seat 42 also has seat heating, this seat heating can also be activated.

[0079] If a child seat is located on the rear vehicle seat 42 and if the occupancy of the rear vehicle seat 42 with the child seat is detected, the control device 46 can cause further second heating devices 50, 52 to be operated, which are arranged in Fig. 1 are shown schematically. For example, one of the further second heating devices 50 can be arranged on a rear side of a backrest 54 of the front vehicle seat 42 and can expose the occupant in the child seat to heat radiation 44 emitted by this further second heating device 50.

[0080] Additionally or alternatively, one of the further second heating devices 52 can be operated, which is arranged on a boundary wall 56 of the passenger compartment 12. The boundary wall 56 of the passenger compartment 12 can be designed, for example, as a ceiling or roof lining of the motor vehicle 10.

[0081] If the control device 46 determines that the expected duration of the journey to be made by the motor vehicle 10 is long, for example because a long distance has to be covered, direct heating by means of the heat radiation 44 can be achieved by initially operating the at least one second heating device 36, which is integrated into the floor mat 38, as well as by operating the seat heating and the steering wheel heating. By emitting the heat radiation 44 from such contact surfaces, a pleasant feeling of warmth can be ensured for the user or occupant of the motor vehicle 10 located in the passenger compartment 12. The control device 46 can then effect slow and thus energy-efficient operation of the first heating device 14 by heating the air flow 16.This is significantly more energy efficient than rapid and strong heating of the air flow 16 by means of the first heating device 14.

[0082] It may happen that the motor vehicle 10 stops at a charging station (not shown) on the way to a destination in order to charge the electrical energy storage device 20. The heat loss arising during the charging process can be used in particular to keep the passenger compartment 12 warm. For this purpose, a Fig. 2 schematically shown radiator 58, through which the waste heat generated during charging of the electrical energy storage device 20 is dissipated. Accordingly, the radiator 58 can be integrated into a coolant circuit 60 of the air conditioning device, wherein the coolant circuit 60 in Fig. 2 is shown only very schematically. In particular, the radiator 58 can be used as the Fig.1, the first heating device 14 can be used, by means of which the air flow 16 that can be introduced into the passenger compartment 12 can be heated.

[0083] The smart air conditioning system, which includes the control device 46, can determine, based on the predicted route, that a comparatively long distance must be covered between two charging options for charging the electrical energy storage device 20. In such a situation, the control device 46 can ensure that the heating of the air flow 16 by the first heating device 14 is reduced in order to increase the range of the motor vehicle 10 in electric driving mode. To avoid any loss of comfort for occupants of the passenger compartment 12, the occupants or passengers can be kept warm in a targeted manner by operating the at least one second heating device 36. This is advantageous with regard to the energy-efficient operation of the air conditioning system.

[0084] Preferably, for example, after a winter walk, the occupant can ensure that the second heating device 36 integrated into the floor mat 38 is activated by performing an operating action on a user interface of the air conditioning system. This provides particularly great flexibility with regard to the operation of the second heating device 36. The smart control of the heating devices 14, 36, 50, 52 of the air conditioning system, which can be effected by means of the control device 46, allows for a multitude of usage scenarios, providing the occupant with a high level of air conditioning comfort without any intervention on their part.

[0085] If the motor vehicle 10 is only intended to travel a short distance, the estimated time required for this is comparatively short. Heating the air flow 16 is then unnecessary. This is because it is sufficient to provide the occupant of the passenger compartment 12 with a pleasant feeling of warmth for the short time expected to be required for traveling the distance by heating those surfaces that the occupant touches. For example, while traveling the short distance, the second heating device 36 integrated into the floor mat 38 can be activated, and / or the seat heating, the steering wheel heating, and / or a knob of a gearshift (not shown) of the motor vehicle 10, or the like.

[0086] If the motor vehicle 10 travels a longer distance, the expected time for this is longer. In this case, the heating of the air flow 16 can be carried out particularly slowly, thus preserving the electrical energy reserves, if the at least one second heating device 36 is also operated. Furthermore, the air flow 16 needs to be heated less intensely than would be the case without the use of the at least one second heating device 36. The electrical energy required to maintain the temperature of the passenger compartment 12 is thus significantly reduced. This is associated with a significant range advantage for the motor vehicle 10.

[0087] While the electrical energy storage device 20 is being charged, the air in the passenger compartment 12 can be preconditioned, depending on the preference of the occupant of the passenger compartment 12, or a warm temperature already prevailing in the passenger compartment 12 can be maintained. This is because the electrical energy required for this purpose is not depleted by the energy reserves of the electrical energy storage device 20, but is supplied via the charging cable (not shown). It is therefore advantageous if the air in the passenger compartment 12 is already heated to a desired temperature during charging.

[0088] When the user of the motor vehicle 10 then unplugs the charging cable and enters the passenger compartment 12, the occupant's perceived warmth can be increased by operating the at least one second heating device 36 or similar contact heaters. A temperature perceived as pleasant or comfortable for the occupant of the passenger compartment 12 can thus be maintained over a longer period of time even without heating the air flow 16 by means of the first heating device 14. This is advantageous.

[0089] Preferably, a smart control of the air conditioning system, which can be implemented during operation of the control device 46, combines climate data with current data on weather conditions or weather data, as well as data from the navigation system 48 and the occupant's charging requests. Depending on the estimated time required to cover the distance, the energy required to cover the distance, the user's request to charge the electrical energy storage device 20 while covering the distance, the estimated time required to charge the electrical energy storage device 20, and the user's air conditioning request, the control device 46 can determine an energy-efficient temperature control strategy.

[0090] Thus, an energy-efficient interaction of the operation of the refrigerant circuit 26 as a heat pump, the use of at least one contact heater, for example in the form of the second heating device 36, a user's request with regard to preferred temperature settings, the charging of the electrical energy storage device 20 and route planning can be effected by the control device 46.

[0091] Overall, the examples show how a floor mat 38 with an integrated second heating device 36, in particular in the form of an infrared heater designed for operation with 12 volts, can be provided.

Claims

[1] Air conditioning device for controlling the temperature of a passenger compartment (12) of a motor vehicle (10), comprising a first heating device (14) which is designed to heat an air flow (16) which can be introduced into the passenger compartment (12), and comprising at least one second heating device (36) which is arranged in the passenger compartment (12) and is designed to subject an occupant of the passenger compartment (12) to heat radiation (44), wherein a control device (46) of the air conditioning device is designed to cause operation of at least the first heating device (14) as a function of an expected duration for a distance to be covered by the motor vehicle (10), characterized bythat the air conditioning device comprises a second heating device (36) which is integrated into a floor mat (38), wherein the second heating device (36) integrated into the floor mat (38) is designed to emit heat radiation (44) when connected to an electrical energy storage device (20) of the motor vehicle (10), wherein the control device (46) is designed to determine the presence of at least one charging station on the route to be covered and a charge state of the electrical energy storage device (20), and depending on the presence and the charge state, to communicate to a user of the motor vehicle (10) a temperature control strategy which, if the charging station is not used, includes reduced heating of the air flow (16) and operation of the at least one second heating device (36), and / or wherein the control device (46) is designed toto create a respective user profile from temperature settings set by a respective user of the motor vehicle and routes traveled by the user and to take the user profile into account for operating the first heating device (14) and / or the at least one second heating device (36). [2] Air conditioning device according to claim 1, characterized by in that the control device (46) is designed to detect a target temperature of the air in the passenger compartment (12) set by a user of the motor vehicle (10) and to cause the air flow (16) to be heated by operating the first heating device (14), which leads to a lower actual temperature of the air than the target temperature, wherein the control device (46) is designed to cause the at least one second heating device (36) to be operated as a function of the actual temperature. [3] Air conditioning device according to one of the preceding claims, characterized by in that the control device (46) is designed to cause at least one further second heating device (50, 52) to operate as a function of the distance to be covered and the occupancy of a vehicle seat (42) of the motor vehicle (10), which heating device is arranged on a further vehicle seat (40) of the motor vehicle (10) and / or on a boundary wall (56) of the passenger compartment (12). [4] Air conditioning device according to one of the preceding claims, characterized by in that the control device (46) is designed to maintain a temperature of the air in the passenger compartment (12) during use of a charging station designed to charge the electrical energy store (20) as a function of weather data and / or an expected time duration for covering a remaining section of the route. [5] Air conditioning device according to one of the preceding claims, characterized by that the first heating device (14) is provided by a heat exchanger of a refrigerant circuit (26) of the air conditioning device and / or by a heating element (58) through which a coolant can flow, wherein the heating element (58) is integrated into a coolant circuit (60) of the air conditioning device, and wherein waste heat generated during charging of the electrical energy store (20) can be supplied to the heating element (58) via the coolant. [6] Air conditioning device according to one of the preceding claims, characterized by in that the control device (46) is designed to detect a number of occupants in the passenger compartment (12) and, depending on the number, to at least temporarily prevent the operation of the first heating device (14) and to cause the operation of at least one second heating device (36). [7] Motor vehicle (10) with an air conditioning device according to one of the preceding claims, wherein the motor vehicle (10) is designed as an electric vehicle or as a hybrid vehicle. [8] Method for operating an air conditioning device designed to control the temperature of a passenger compartment (12) of a motor vehicle (10), wherein a first heating device (14) of the air conditioning device is designed to heat an air flow (16) that can be introduced into the passenger compartment (12), wherein at least one second heating device (36) of the air conditioning device is arranged in the passenger compartment (12) and exposes an occupant of the passenger compartment (12) to heat radiation (44), wherein a control device (46) of the air conditioning device causes at least the first heating device (14) to be operated as a function of an expected duration for a distance to be covered by the motor vehicle (10), characterized bythat the air conditioning device comprises a second heating device (36) which is integrated into a floor mat (38), wherein the second heating device (36) integrated into the floor mat (38) emits heat radiation (44) when connected to an electrical energy storage device (20) of the motor vehicle (10), wherein the control device (46) determines the presence of at least one charging station on the route to be covered and a charge state of the electrical energy storage device (20) and, depending on the presence and the charge state, communicates a temperature control strategy to a user of the motor vehicle (10), which, if the charging station is not used, includes reduced heating of the air flow (16) and operation of the at least one second heating device (36),and / or wherein the control device (46) creates a respective user profile from temperature settings set by a respective user of the motor vehicle (10) and routes traveled by the user and takes the user profile into account for operating the first heating device (14) and / or the at least one second heating device (36).

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