Vehicle and method for air conditioning a vehicle

Abstract

vehicle (2), with a passenger compartment (4), with a motor unit (8) which generates waste heat, the motor unit (8) serving to drive the vehicle (2), with an absorption air conditioning system (6) which has an evaporator (10), an absorber (12) and a cooker (14), wherein the cooker (14) is integrated into the motor unit (8) and is positively fastened in or on the motor unit (8), and with a control unit (36) which is designed such that it sets a cooling operation in which - the passenger compartment (4) is cooled by evaporating a refrigerant in the evaporator (10), - the refrigerant is absorbed in the absorber (12) by an absorption medium and - the refrigerant is released in the cooker (14) by heating the absorption medium with the waste heat of the motor unit (8).

Description

The invention relates to a vehicle and to a method for air-conditioning a vehicle.The air conditioning of a vehicle is usually carried out by means of an air conditioning system. Such an air conditioning system serves in particular for the heat dissipation and thus for the generation of cold, as a result of which cooling of the passenger compartment of a vehicle is made possible. For generating refrigeration, a compression air conditioner is typically used, including a compressor, an evaporator, an expansion valve, and a condenser. The compressor is usually used to generate the required cooling power independently of the operating state of the vehicle. The compressor must be driven accordingly and is for this purpose coupled, for example, to the belt drive of the vehicle or is driven by an electric motor. For this purpose, energy is required which is correspondingly secondary energy, i.e. mechanical energy which is generated by an internal combustion engine, electrical energy which is generated by an electrical generator in the belt drive of the internal combustion engine, or on-board power, i.e. in particular electrical energy from an energy store of the vehicle. Such an energy store is, for example, a 12V lead battery or a 48V / 350V Li store, generally also referred to as a high-voltage store.The secondary energy required for cooling the passenger compartment is under certain circumstances and, depending on the operating state, of the same order of magnitude as the drive power of the vehicle, and therefore represents a not negligible item in the energy consumption of the vehicle.For air conditioning, fuel or electrical energy is consumed, which has a disadvantageous effect on the consumption and the range of the vehicle.Reference is made to US 2006 / 0107674 A1, P 2011-242 017 A, DE 42 07 857 A1, DE 10 2012 213 906 A1, DE 10 2012 221 569 A1 and JP H01 267 346 A.Against this background, it is an object of the invention to specify a vehicle with improved air conditioning. The air conditioning should take place as efficiently as possible. The vehicle should overall have the lowest possible energy consumption and nevertheless offer the highest possible comfort with regard to the air conditioning. Furthermore, a corresponding method for air conditioning a vehicle is to be specified.The object is achieved according to the invention by a vehicle having the features according to claim 1 and by a method having the features according to claim 15. The explanations in connection with the vehicle also apply analogously to the method and vice versa.The vehicle has a passenger compartment in which occupants may be located. Furthermore, the vehicle has an engine unit which generates waste heat. The motor unit is also referred to as a motor for short. The engine unit preferably consists of an internal combustion engine and in this embodiment has in particular an engine block with a crankcase. The motor unit serves to drive the vehicle and is part of a corresponding drive train. In particular during the drive, i.e. in the active state, the motor unit then generates waste heat. In one variant, the motor unit has an electric motor. In this variant, the motor unit also has, in particular, power electronics which actuate the electric motor and which generate, in particular, waste heat. Such an electric motor is usually supplied with energy by means of a high-voltage accumulator, which then likewise generates waste heat. Alternatively or additionally, the motor unit has an electric motor and a fuel cell which supplies the electric motor with energy. A fuel cell generates particularly much waste heat during operation, in particular significantly more waste heat than the electric motor. In particular, the motor unit as a whole thus consists of a drive machine and, if appropriate, an energy store.Various concepts for the motor unit are suitable, in particular those mentioned below. In some embodiments, the vehicle has a high-voltage accumulator which, depending on the specific embodiment, performs different functions:engine unit, comprising an internal combustion engine for driving. In this embodiment, the motor unit does not have an electric motor and also no high-voltage accumulator. The vehicle is a vehicle operated purely by an internal combustion engine.engine unit, comprising an internal combustion engine for driving. In this embodiment, the motor unit does not have an electric motor. A high-voltage accumulator is used for supplying energy to consumers in the vehicle which have a high electrical energy requirement, e.g. an electric charge air compressor or an electric roll stabilization, and in particular also require a high operating voltage, i.e. in particular 48 to 350 V. The vehicle is then a purely internal combustion engine-driven vehicle.engine unit, consisting of an internal combustion engine and an electric motor, each for driving, and power electronics for controlling the electric motor. A high-voltage accumulator is used to supply energy to the electric motor. The vehicle is then a hybrid vehicle.motor unit, consisting of an electric motor for driving and power electronics for controlling the electric motor. A high-voltage accumulator is used to supply energy to the electric motor. The vehicle is then an electric vehicle.motor unit, consisting of an electric motor for driving and an internal combustion engine as a range extender, for charging a high-voltage accumulator, and power electronics for controlling the electric motor. The high-voltage accumulator serves to supply energy to the electric motor. The vehicle is then an electric vehicle with range extender.motor unit, comprising an electric motor for driving and a fuel cell as a range extender for charging a high-voltage accumulator, and power electronics for controlling the electric motor. The high-voltage accumulator serves to supply energy to the electric motor. The vehicle is then a fuel cell vehicle, also referred to as an FCEV (fuel cell electric vehicle).motor unit, comprising an electric motor for driving, and a fuel cell for supplying energy to the electric motor, and power electronics for controlling the electric motor. A high-voltage accumulator is used to supply energy to consumers which have a high electrical energy requirement, for example in order to bypass a high-start phase of the fuel cell. The vehicle is then a fuel cell vehicle, also referred to as an FCEV (fuel cell electric vehicle).The term "consisting of" is understood in particular to mean that the motor unit only has those components which form the motor unit.The vehicle also has an absorption air conditioning system which has an evaporator, an absorber and a cooker. In addition, a control unit is arranged, which is designed such that it sets a cooling operation.In the cooling operation, the passenger compartment is cooled by evaporating a refrigerant in the evaporator, i.e., evaporated refrigerant is generated. The refrigerant, more precisely the vaporized refrigerant, is absorbed in an absorber by an absorption medium, i.e. absorbed refrigerant is generated. In particular, the vaporized refrigerant is thereby removed from the evaporator, so that further, liquid refrigerant flows in and continuous cooling is realized. Furthermore, the refrigerant, which is absorbed in particular, is released in a cooker by heating the absorption medium with the waste heat of the engine unit. The waste heat of the motor unit is thus used as heating heat for heating the absorption medium in the cooker. Depending on the configuration of the motor unit, the waste heat is then generated by a drive machine, e.g. an internal combustion engine or an electric motor, and / or by an energy store for supplying the drive machine, e.g. a high-voltage store or a fuel cell.Overall, a circuit thus results for the refrigerant, in which the refrigerant initially absorbs heat in the evaporator and is evaporated. The refrigerant is then removed from the evaporator by means of the absorber in order to allow further refrigerant to flow in. The absorption medium is then loaded with refrigerant. The loaded absorption medium is then fed to the digester in order to release the refrigerant again there by means of heat supply and to regenerate the absorption medium. The regenerated absorption medium is again fed to the absorber. The released refrigerant is returned to the evaporator. Expediently, the refrigerant released is cooled in a condenser and only then is it fed back to the evaporator. Overall, the absorption air conditioning system has two circuits which overlap, namely a refrigerant circuit and an absorption medium circuit. Both circuits overlap from the absorber, in which refrigerant and absorption medium are mixed, to the digester, in which refrigerant and absorption medium are separated from one another.Particular advantages result from the use of an absorption air conditioning system. Such a device is particularly quiet in operation. At the same time, continuous operation is advantageously also possible, i.e. continuous cooling or provision of cold. This results in particular from the above-described configuration with two circuits. Since the refrigerant circulates and evaporated refrigerant is continuously drawn out of the evaporator and liquid refrigerant is supplied, continuous cooling is ensured.An absorption air conditioning system furthermore has the advantage that it can be operated even at a low temperature gradient of, for example, a few degrees Celsius, wherein the temperature gradient between the cooker and the evaporator is measured, which is already advantageous when the absorption air conditioning system is started to operate. Continuous operation over wide temperature and temperature gradient ranges is also possible. With regard to operation, the absorption air conditioning system is additionally advantageously self-regulating in terms of the fact that it automatically starts operation at a corresponding temperature gradient and that the cooling power likewise increases with increasing heating heat. An absorption air conditioning system can also be operated even at low external temperatures, i.e. in particular below 0° C., at which a compression air conditioning system is not operable. As a result, cooling can be achieved even in winter, for example for particularly cooling-intensive vehicle components such as a fuel cell, or as an alternative to cooling by means of ambient air if this is not intended to be used or can not be used.A core idea of the invention is in particular to use the waste heat of the engine unit, in particular instead of discharging it to the environment via a cooler. A particular advantage here is that, owing to the use of an absorption air conditioning system, the waste heat can also be used for cooling, i.e. for generating a cooling capacity, and is also used in cooling operation. In particular in summer, when the thermal load in the vehicle is particularly high, the waste heat of the engine unit can then be used efficiently for air conditioning the passenger compartment. No secondary energy needs to be used. The fuel or the electrical energy of the vehicle is advantageously maintained for the travel operation and is not required for air conditioning the vehicle. In the case of the use of waste heat of the energy store, the same waste heat which inevitably arises during operation of the energy store is still advantageously used. Overall, less CO2is advantageously produced. This is also advantageous above all with regard to the future calculation of the energy consumption of an air conditioning system, in particular within the scope of the WLTP. The use of the waste heat from the engine unit advantageously reduces the future calculated proportion of the air conditioning in terms of energy consumption.The engine unit is thus advantageously coupled to the absorption air conditioning system in order to use the waste heat of the engine unit for operating the absorption air conditioning system and ultimately for cooling the passenger compartment. The waste heat is used particularly efficiently and no longer has to be discharged to the environment via a cooler, at least not completely. Since the design of a cooling field or cooler for heat dissipation is usually oriented to extreme conditions, in particular in summer, an additional heat sink is created by the absorption air-conditioning system, as a result of which it is advantageously possible to dimension the cooler smaller or completely dispense with such a cooler and thereby save weight and installation space. In particular, since the absorption air conditioning system is typically used primarily in summer. The absorption air conditioning system in this way also forms, in particular, an advantageous engine cooling system. In addition, separate, removed coolers are expediently dispensed with. This is based on the idea that it is possible in principle to expand the cooling field of the vehicle by means of discharged coolers, for example in the wheel arch. Such exhausted coolers are, however, advantageously not necessary when using an absorption air conditioning system, since less waste heat has to be removed in this configuration. As a result, more installation space is available for other functions in the vehicle, for example in the wheel arch.The absorption air conditioner, also referred to as an absorption chiller, is a chiller in which, unlike a compression chiller, a refrigerant at low temperature is absorbed in an absorption medium, also referred to as a solvent, and desorbed at higher temperatures compared thereto. The temperature dependence of the physical solubility of two substances is utilized. For example, ammonia is used as the refrigerant, and water is used as the absorption medium, suitably in a hydrogen atmosphere. The use of an absorption air conditioning system is particularly simple, since it can be implemented and operated with minimal mechanical complexity. Such an absorption air conditioning system is also particularly quiet during operation, especially in comparison with a compression air conditioning system. Such a system is preferably omitted.In order to use the waste heat of the engine unit, i.e. the engine waste heat, the cooker is connected to the engine unit. For example, an engine cooling circuit is suitable, to which the engine unit and the cooker are connected and in which a heat transfer medium circulates. The cooker is incorporated as efficiently as possible into an already existing engine cooling concept. For this purpose, the cooker is positioned in particular in the engine cooling circuit in such a way that the cooker is operated primarily in front of a cooler or cooling field, so that waste heat is first supplied to the cooker and only then is any excess waste heat discharged via the cooler. An already present cooler or a cooling field can then advantageously be of smaller dimension, since a part of the waste heat no longer needs to be discharged, but rather is used for operating the absorption air conditioning system.In the present case, the cooker is integrated into the motor unit. In other words, a separate circuit for heat transfer is dispensed with, but rather the cooker is mounted directly and directly in or on the motor unit. As a result, the transfer of the waste heat from the motor unit to the cooker is particularly efficient. During operation, the motor unit has a specific core temperature, which is then advantageously also used directly on the cooker. In particular, a power potential of 10 to 20 kW is thereby established. In contrast, in a separate arrangement of cooker and motor unit, a temperature drop would necessarily take place on the way to the cooker, with disadvantageous effects on the efficiency.Suitably, the two above concepts are combined and the cooker is both integrated directly into the motor unit and connected to a motor cooling circuit. This realizes optimum utilization of the waste heat. In addition, the concept of an absorption air-conditioning system can be integrated in a simple manner into existing engine concepts without having to fully redesign the engine unit. Rather, the cooker is mounted at a suitable location in or on the engine unit and an already present engine cooling circuit is connected, preferably in such a way that the cooker is supplied with waste heat from the engine unit predominantly upstream of a cooler.Expediently, however, the design and accommodation of the cooker is already taken into account in the design or in the design of the motor unit, so that a particularly high integration results. The cooker is then, for example, a part of an engine block or engine housing, which then has corresponding connections for the refrigerant and optionally the absorption medium. A particularly suitable configuration assumes that an insulation material, e.g. an insulation pad, is usually attached to and / or in a motor unit, in particular in an internal combustion engine. The insulation material serves in particular for the thermal and acoustic insulation of the motor unit. In such a motor unit, at least a part of the insulation material is then replaced by the cooker. In this way, already existing motor units can be advantageously converted. A complete redesign is not necessary.In order to achieve a particularly optimum heat transfer, the cooker is fastened positively in or on the motor unit. The aim here is as intensive a thermal coupling as possible and an optimum thermal transition. This is achieved in particular in that any air inclusions, gaps or the like are advantageously avoided, so that the waste heat is efficiently and quickly transferred.In an advantageous embodiment, the engine unit serves as a particularly sensitive heat store, for storing waste heat in an active state and for providing heat in an inactive state. In this embodiment, the generation of the waste heat and the use thereof for heating the cooker are thus advantageously separated from one another in time. This makes use of the fact that the engine unit, and in particular an engine block and / or a crankcase of the engine unit, is manufactured from a specific amount of material which represents a thermal mass and stores a specific amount of heat. Moreover, depending on the configuration of the engine unit, oil, i.e. engine oil, and / or coolant from an engine cooling circuit additionally also serve as thermal mass. In an active state, for example when driving the vehicle, the motor unit generates waste heat and stores it, i.e. the material is heated. At a later point in time, the stored waste heat is then removed and supplied to the cooker in order to cool the passenger compartment even in the inactive, i.e. switched-off state. Such an inactive state results, for example, in the parking mode of the vehicle or, in the case of a vehicle with automatic engine start-stop system, during a brief stop, for example at a traffic light.The above-described concept with the engine unit as a heat store is suitable in principle for any vehicle. However, this configuration is particularly suitable for a vehicle having an internal combustion engine, the waste heat of which is used and transmitted to the cooker, since an internal combustion engine is usually of particularly massive design and represents a particularly large thermal mass. Correspondingly long phases can then be bridged in the inactive state, for example 10 to 20 min, for example if after a short-term parking there is continued travel. Vehicles with an internal combustion engine are, in particular, vehicles operated purely by the internal combustion engine, hybrid vehicles and also electric vehicles with a so-called range extender, that is to say vehicles with an electric motor and an internal combustion engine for charging the high-voltage accumulator. Using the example of a hybrid vehicle having an electric motor and an internal combustion engine, the advantage becomes particularly clear: continuous cooling is ensured in the case of alternating operation of the internal combustion engine and of the electric motor, i.e. in mixed operation or alternating operation. In phases in which the electric motor is active and the internal combustion engine is inactive, waste heat from the still warm internal combustion engine is used. One phase is, for example, about 10 minutes. Air conditioning of the passenger compartment is then possible without the internal combustion engine being switched on and without the onboard power being consumed.During operation of the absorption air conditioning system, the refrigerant and the absorption medium must be circulated. For this purpose, a pump is expediently used, which is arranged, for example, between the absorber and the digester and conveys the absorption medium to the digester after the absorption of refrigerant. However, by a suitable design of the absorption air conditioning system, it is also possible to dispense with a pump for circulation, i.e. the absorption air conditioning system is then designed without a pump. In this expedient embodiment, the refrigerant and the absorption medium are circulated only by means of the so-called thermosiphon effect. As a result, the absorption air conditioning system is particularly simple in construction, low-maintenance and quiet. In the thermosiphon effect, use is made of the fact that the density of a substance changes, in particular decreases, with increasing temperature, with the result that circulation takes place automatically solely on account of gravity.In a particularly suitable embodiment, the evaporator is arranged at a higher location in the vehicle with respect to the cooker. This particularly promotes circulation by means of the thermosiphon effect. A pump can then advantageously be dispensed with. Alternatively, a pump is used only as an auxiliary.The evaporator is situated higher relative to the cooker, so that the thermosiphon effect can be utilized for circulating the refrigerant, and a circulation pump can be dimensioned smaller or no pump is required at all. This is based on the finding that the refrigerant is warmer in the cooker than in the evaporator and then automatically rises and circulates when the cooker is lower.The evaporator and the cooker are connected by means of a line which has a specific line length which is as short as possible in order to realize as low heat losses as possible. At the same time, however, a maximum height difference between the evaporator and the cooker is advantageous. A configuration has proven to be particularly effective in which the height difference is at least 20 cm, i.e. in which the evaporator is arranged at least 20 cm higher than the cooker. An upper limit for the height difference is given in particular by the usual dimensions for the vehicle and is, for example, 1.5 m.In order to make the lines particularly short, a cooling circuit is expediently connected to the evaporator. As a result, the evaporator is arranged in the spatial vicinity of the cooker and the lines for the refrigerant and the absorption medium are particularly short. Nevertheless, by means of the cooling circuit, an optimum distribution of the cold in the vehicle, i.e. an optimum cooling of the passenger compartment, is possible. The cooling circuit correspondingly extends at those locations in the vehicle at which the passenger compartment or air flowing into the latter is to be cooled. The absorption air conditioning system remains particularly compact.Preferably, in addition to the motor unit, further heat sources are connected to the absorption air conditioning system. In other words: the cooker is preferably thermally connected to at least one further vehicle component which generates waste heat, in order to transfer this waste heat to the cooker. This makes it possible to continue to operate the absorption air conditioning system in the event of a lack of waste heat from the engine unit and to produce or maintain corresponding comfort in the passenger compartment. In principle, several variants are conceivable. In a first variant, the vehicle component is mounted directly on the cooker. This variant is particularly suitable for a vehicle component which is arranged in the spatial vicinity of the engine unit. In a second variant, a circuit with a heat transfer medium is formed, to which the vehicle component and the cooker are connected. This variant is particularly suitable for a vehicle component which is arranged at some distance from the engine unit. In a third variant, the cooker is formed in multiple parts or a plurality of cookers are formed, which are arranged at different points of the vehicle, namely in each case on a heat source, namely on the one hand in or on the engine unit and on the other hand on the further vehicle component. A combination of the aforementioned variants is also possible and suitable.In general for cooling a plurality of vehicle components, the absorption air conditioning system is expediently designed with a plurality of evaporators or a multipart evaporator, in order in particular to fulfil various air conditioning tasks. Various air-conditioning tasks are in particular those which are conventionally operated via a low-temperature cooling circuit, for example cooling electronic components or vehicle seats. The configuration with a plurality of evaporators or with a multipart evaporator is expediently combined with a configuration with a plurality of digesters or with a multipart digester. This ensures a particularly flexible air conditioning overall.In a particularly preferred embodiment, the vehicle components are an engine oil circuit or an oil sump of the vehicle. This allows, on the one hand, additional heat to be obtained for the operation of the absorption air-conditioning system. On the other hand, in this embodiment, a particularly suitable height difference is obtained between the cooker and the evaporator. The evaporator is arranged in particular at half the height in the vehicle, that is to say on a central plane via which air is flown into the passenger compartment approximately at the chest height of the occupants. The cooker or a part thereof is then preferably arranged in the oil sump, i.e. an oil pan, and thus at a particularly low point in the vehicle. This results in an advantageous height difference of about 50 cm. Accommodation of the cooker generally in the engine oil circuit results in a similarly advantageous height difference. The arrangement in the oil sump is preferred, however, since here a particularly large contact surface is also formed and thus a particularly efficient heat transfer is ensured. In addition, when the vehicle is started, the engine oil is initially warm, so that already shortly after the engine unit is started, heat is spontaneously available to operate the absorption air-conditioning system.Under certain circumstances, the waste heat from the engine unit and possibly from further vehicle components is not sufficient to achieve the desired air conditioning by means of the absorption air conditioner. Therefore, in an advantageous development, the vehicle component is a supplementary heater for the additional generation of heat as required, i.e. heating heat for the cooker. In other words: in the case of insufficient waste heat, heating is carried out by means of a supplementary heater. This ensures maximum comfort at any particular time. The auxiliary heater is, for example, a fuel auxiliary heater or an electric continuous flow heater. However, a configuration is particularly suitable in which the vehicle has a parking heater which at the same time serves as the auxiliary heater.The auxiliary heater is preferably connected to the cooker by means of a separate auxiliary heater circuit, which is in particular a water circuit. A heat transfer medium, for example water, circulates in the auxiliary heater circuit, which medium makes a particularly large contact surface possible, as a result of which the heat transfer is particularly large. In particular, if the cooker is integrated into the motor unit, heating is also possible without having to integrate the heater likewise into the motor unit. The auxiliary heater circuit is designed to be spatially limited as possible in order to ensure as low a heat transfer as possible. This is realized in particular by the shortest possible line lengths for the auxiliary heater circuit.Furthermore, it is advantageously possible to connect and heat further vehicle components to the auxiliary heater circuit. The auxiliary heater is then used for a plurality of functions. In a particularly advantageous embodiment, the auxiliary heater is designed as a parking heater for heating the passenger compartment. In a heating mode, the passenger compartment is then heated by means of the auxiliary heater. For example, a heating heat exchanger is connected to the auxiliary heater circuit, which heating heat exchanger heats air, which is then flown into the passenger compartment.For cooling the motor unit, the vehicle has, in particular, a motor cooling circuit for cooling the motor as required. Connected to this is in particular a cooler, via which excess waste heat, i.e. waste heat not required for cooling or for heating, is discharged to the environment. Alternatively or additionally to the above-mentioned embodiments, the auxiliary heater is expediently connected to the engine cooling circuit, for engine heating as required, and can then also be used for preheating the engine unit and / or the engine oil. This realizes an advantageous engine heating and the cold start phase is advantageously shortened. In this case, the engine oil is preheated in particular to a temperature at which the viscosity of the engine oil is already in its intended operating range. The optimum operating temperature does not necessarily have to be reached, but rather a slight preheating to, for example, approximately 10° C. is sufficient in order to achieve a significant shortening of the cold start phase. In one variant, the engine cooling circuit corresponds to the auxiliary heater circuit. Alternatively, the engine cooling circuit and the auxiliary heater circuit are formed as separate circuits. In a development, the engine unit and or the engine oil are preheated by means of the auxiliary heater in a preheating mode. This is particularly useful if the vehicle has a heating element, which is then at the same time the auxiliary heater, so that the heating element is also used as an engine or engine oil heater and / or as a heat source for the absorption air conditioning system, depending on the operating state and depending on the need. For example, a hybrid vehicle is started in the electric mode in which the internal combustion engine is inactive and then the internal combustion engine is preheated in a predictive manner in order to reduce or completely eliminate the cold start phase in a subsequent combustion mode. A possible situation is, for example, a start of a trip in a residential area in electric mode and a subsequent approach to an expressway with activation of the internal combustion engine.In a particularly preferred embodiment, the above-mentioned embodiments are combined with respect to the auxiliary heater in such a way that it is designed as an auxiliary heater and is used for heating the passenger compartment, for heating the engine and for heating the cooker. These three functions are combined with one another in corresponding operating modes and set by the control unit in order to achieve optimum air conditioning of the engine unit and of the passenger compartment by cooling, heating or dehumidifying.The method is used for air conditioning a vehicle, having a passenger compartment, having an engine unit which generates waste heat, having an absorption air conditioning system which has an evaporator, an absorber and a cooker. In the method, a cooling operation is set in which the passenger compartment is cooled by evaporating a refrigerant in the evaporator, the refrigerant is absorbed by an absorption medium in an absorber, and the refrigerant is released in a cooker by heating the absorption medium with the waste heat of the engine unit. Practical embodiments and advantages are obtained analogously from the above explanations.An exemplary embodiment of the invention is explained in more detail below with reference to a drawing. The schematic figures show: FIG. 1 shows a vehicle, and FIG. 2 shows a motor unit and an absorption air conditioner.FIG. 1 shows a vehicle 2 having a passenger compartment 4 which is air-conditioned by means of an absorption air-conditioning system 6. This is connected to an engine unit 8 of the vehicle 2 for the purpose of heat transfer. The motor unit 8 generates waste heat, which is used as heating heat for supplying the absorption air conditioner 6. In the exemplary embodiment shown, the motor unit 8 is an internal combustion engine, in particular for driving the vehicle 2. the vehicle 2 is accordingly here a vehicle 2 operated purely by an internal combustion engine, a hybrid vehicle or an electric vehicle in which the internal combustion engine is used as a range extender. In one variant, the motor unit 8 is an electric motor, the vehicle 2 is then an electric or hybrid vehicle.The air conditioning is explained in more detail below with reference to FIG. 2. This shows the absorption air conditioning system 6 and further parts of the vehicle 2 in a highly schematic manner.The absorption air conditioner 6 includes an evaporator 10 in which a refrigerant is evaporated. Heat is thereby extracted from the surroundings of the evaporator 10 and cooling is realized. This is used in a cooling mode to remove heat from the passenger compartment 4 and to cool it. The vaporized refrigerant is absorbed by an absorption medium in an absorber 12. As a result, the vaporized refrigerant is removed from the evaporator 10, so that further liquid refrigerant flows in and continuous cooling is realized. Furthermore, the absorbed refrigerant is released again in a digester 14 by heating the absorption medium with heating heat. The heating heat is supplied from the motor unit 8. In addition, in FIG. 2, the refrigerant released is still cooled in a condenser 16 and is only then fed again to the evaporator 10. Overall, the absorption air conditioning system 6 thus has two circuits 18, 20 which overlap, namely a refrigerant circuit 18 and an absorption medium circuit 20.In order to achieve an optimum heat transfer, the cooker 14 is integrated in the present case in a positively locking manner into the motor unit 8, in particular instead of a conventional insulation. As a result, the core temperature of the motor unit 8 is accessible for heating the cooker 14. The engine unit 8 is also used as a thermal mass, so that waste heat is stored in the crankcase or in the engine block and is also available at a later point in time. In particular, heating heat is still available even when the motor unit 8 is in an inactive state, i.e. is switched off.In addition, the engine unit 8 has an oil sump 22, and the cooker is accommodated in the engine unit 8 in such a way that the cooker 14 also removes waste heat from the oil sump 22. As a result, the cooker 14 is also installed in the vehicle to a particularly low level and at least lower than the evaporator 10, so that a pump is dispensed with for circulating the refrigerant and the absorption medium in the two circuits 18, 20. Instead, a height difference of at least 20 cm, preferably 50 cm, is formed between the evaporator 10 and the cooker 14 and the circulation takes place solely by means of the thermosiphon effect.The vehicle 2 also has an auxiliary heater 24, which in the exemplary embodiment shown is at the same time an auxiliary heating of the vehicle 2 and is also used for heating the passenger compartment 4 in a heating mode. The auxiliary heater 24 is connected to the cooker 14 via an auxiliary heater circuit 26 that is as small as possible in order to supply the cooker with heating heat if the motor unit 8 generates no waste heat or only an insufficiently large amount of waste heat. The motor unit 8 itself is also connected to the auxiliary heater circuit 26, so that the motor unit 8 can also be heated in the sense of heating or preheating the motor. In a variant which is not shown, in addition or as an alternative to the engine unit 8, the oil sump 22 is connected to the auxiliary heater 24 in order to realize an engine oil heating.In FIG. 2, the auxiliary heater circuit 26 serves at the same time as an engine cooling circuit 28, to which a cooler 30 is connected, for the discharge of waste heat from the engine unit 8 to the environment. By means of the same circuit, heating and cooling of the motor unit 8 is accordingly possible. In a variant which is not shown, the engine cooling circuit 28 and the auxiliary heater circuit 26 are designed as circuits 26, 28 which are separate from one another. Nevertheless, in an embodiment with separate circuits 26, 28, the auxiliary heater 24 is expediently thermally connected to both circuits 26, 28.In order to make the absorption air conditioning system 6 as compact as possible, a cooling circuit 32 is connected to the evaporator 10 for distributing the cooling capacity of the absorption air conditioning system 6, in which cooling circuit water circulates, for example. In addition, a heat exchanger 34 is connected to the cooling circuit 32 here, which serves for cooling the passenger compartment 4. Due to the cooling circuit 32, the cooling power can be introduced at any point in the vehicle 2 without having to lead the lines of the absorption air conditioning system 6 to this point.The absorption air conditioning system 6 and in particular also some or all of the remaining vehicle components are controlled by a control unit 36, which is, for example, a central control unit 36 of the vehicle 2. The control unit 36 also sets a cooling and / or a heating operation depending on the need or the air conditioning requirement.List of reference characters2 Vehicle 4 Passenger compartment 6 Absorption air conditioning system 8 Engine unit 10 Evaporator 12 Absorber 14 Cooker 16 Condenser 18 Refrigerant circuit 20 Absorption medium circuit 22 Oil sump 24 Auxiliary heater 26 Auxiliary heater circuit 28 Engine cooling circuit 30 Cooler 32 Cooling circuit 34 Heat exchanger 36 Control unit

Claims

Vehicle (2), having a passenger compartment (4), having an engine unit (8) which generates waste heat, the engine unit (8) serving for driving the vehicle (2), having an absorption air-conditioning system (6) which has an evaporator (10), an absorber (12) and a cooker (14), the cooker (14) being integrated into the engine unit (8) and being fastened in a positively locking manner in or on the engine unit (8), and having a control unit (36) which is designed such that it sets a cooling operation in which - the passenger compartment (4) is cooled by a refrigerant being evaporated in the evaporator (10), - the refrigerant in the absorber (12) is absorbed by an absorption medium and - the refrigerant in the cooker (14) is released by the absorption medium being heated with the waste heat of the engine unit (8).Vehicle (2) according to one of the preceding claims, characterized in that the motor unit (8) has an electric motor and a fuel cell, wherein the fuel cell generates waste heat, by means of which the absorption medium is heated.Vehicle (2) according to one of the preceding claims, characterized in that the engine unit (8) serves as a heat store, for storing waste heat in an active state and for providing waste heat in an inactive state.Vehicle (2) according to one of the preceding claims, characterized in that the absorption air-conditioning system (6) is designed in such a way that the refrigerant and / or the absorption medium are circulated during operation only by means of the thermosiphon effect.Vehicle (2) according to the preceding claim, characterized in that the evaporator (10) is arranged at a higher position with respect to the cooker (14), so that the thermosiphon effect can be utilized for circulating the refrigerant.Vehicle (2) according to the preceding claim, characterized in that the evaporator (10) is arranged at least 20 cm higher than the cooker (14).Vehicle (2) according to one of the preceding claims, characterized in that a cooling circuit (32) for cooling the passenger compartment (4) is connected to the evaporator (10).Vehicle (2) according to one of the preceding claims, characterized in that the cooker (14) is thermally connected to at least one further vehicle component (22, 24), which generates waste heat, for the transmission of this waste heat to the cooker (14).Vehicle (2) according to the preceding claim, characterized in that the vehicle component (22, 24) is an engine oil circuit or an oil sump (22).Vehicle (2) according to one of the two preceding claims, characterized in that the vehicle component (22, 24) is a supplementary heater (24) for the additional generation of heat for the cooker (14) as required.Vehicle (2) according to the preceding claim, characterized in that the auxiliary heater (24) is thermally connected to the cooker (14) by means of a separate auxiliary heater circuit (26).Vehicle (2) according to one of the two preceding claims, characterized in that the auxiliary heater (24) is designed as an auxiliary heater for heating the passenger compartment (4).Vehicle (2) according to one of Claims 10 to 12, characterized in that the engine unit (8) is connected to an engine cooling circuit (28), for engine cooling as required, and in that the auxiliary heater (24) is connected to the engine cooling circuit (28), for engine heating as required.Vehicle (2) according to one of the preceding claims, characterized in that the absorption air conditioning system (6) is designed with a plurality of evaporators (10) or a multi-part evaporator (10), in order in particular to fulfil different air conditioning tasks.Method for air-conditioning a vehicle (2), having a passenger compartment (4), having an engine unit (8) which generates waste heat, the engine unit (8) serving for driving the vehicle (2), having an absorption air-conditioning system (6) which has an evaporator (10), an absorber (12) and a cooker (14), the cooker (14) being integrated into the engine unit (8) and being fastened positively in or on the engine unit (8), wherein a cooling operation is set in which - the passenger compartment (4) is cooled by evaporating a refrigerant in the evaporator (10), - the refrigerant in the absorber (12) is absorbed by an absorption medium, and - the refrigerant in the cooker (14) is released by heating the absorption medium with the waste heat of the engine unit (8).

Images