DE102017200408A1 - VEHICLE AND METHOD FOR AIR-CONDITIONING A VEHICLE - Google Patents

Abstract

The invention relates to a vehicle (2), which is preferably designed as an electric or hybrid vehicle or fuel cell vehicle, with a high-voltage accumulator (4) and with a motor unit (8), which generates waste heat, with an absorption air conditioner (6), which contains an evaporator ( 14), an absorber (16) and a digester (18), the digester (18) being integrated in the motor unit (8), and a control unit (32) arranged to perform an HVS cooling operation in which the high-voltage accumulator (4) is cooled by vaporizing a refrigerant in the evaporator (14), absorbing the refrigerant in an absorber (16) from an absorption medium, and releasing the refrigerant in a digester (18), the absorption medium with the waste heat of the motor unit (8) is heated. Furthermore, a method for the air conditioning of such a vehicle (2) is specified.

Description

The invention relates to a vehicle and 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 is used in particular for heat dissipation and thus the generation of cold, whereby cooling of the passenger compartment of a vehicle is made possible. To generate refrigeration, a compression air conditioning system is typically used, including a compressor, an evaporator, an expansion valve, and a condenser. The compressor is usually used regardless of the operating condition of the vehicle to generate the required cooling capacity. In this case, the compressor must be driven accordingly and for this purpose, for example, coupled to the belt drive of the vehicle or is driven by an electric motor. This requires energy which is corresponding to secondary energy, i. mechanical energy generated by an internal combustion engine, electrical energy generated by an electric generator in the belt drive of the internal combustion engine, or on-board current, i. 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 storage, also commonly referred to as high-voltage storage. Especially in an electric or hybrid vehicle energy for air conditioning is often taken from the high-voltage storage, which is primarily intended to power the drive of the vehicle. An air conditioning system as an additional consumer then directly affects range-reducing.

In an electric or hybrid vehicle especially its high-voltage storage requires regular cooling. In operation falls on the high-voltage storage sometimes a non-negligible waste heat, which leads to a warming of the high-voltage accumulator and its premature aging or in extreme cases to damage. Therefore, the high-voltage storage is usually connected to the air conditioning system to be cooled accordingly. As a result, this leads to the paradoxical situation that additional energy is taken from the high-voltage accumulator in order to cool the high-voltage accumulator itself.

In the DE 10 2008 039 908 A1 a device is described for cooling a battery of a vehicle. For cooling the battery, an absorption chiller is arranged, which is operated in a development with heat loss of an internal combustion engine. The energy consumption of the absorption chiller is thereby reduced.

Against this background, it is an object of the invention to provide a vehicle with improved air conditioning. The air conditioning should be as efficient as possible. Overall, the vehicle should have the lowest possible energy consumption and still offer the highest possible comfort in terms of air conditioning. Furthermore, a corresponding method for the air conditioning of a vehicle should be specified.

The object is achieved by a vehicle with the features of claim 1 and by a method having the features of claim 17. Advantageous embodiments, developments and variants are the subject of the dependent claims. The remarks in connection with the vehicle apply mutatis mutandis to the process and vice versa.

• - Motoreinheit, bestehend aus einem Verbrennungsmotor zum Antrieb. In dieser Ausgestaltung weist die Motoreinheit keinen Elektromotor auf. Ein Hochvoltspeicher dient zur Energieversorgung von Verbrauchern im Fahrzeug, welche einen hohen elektrischen Energiebedarf haben, z.B. ein elektrischer Ladeluftkompressor oder eine elektrische Wankstabilisierung, und insbesondere auch eine hohe Betriebsspannung benötigen, d.h. insbesondere 48 bis 350V. Das Fahrzeug ist dann ein rein verbrennungsmotorisch angetriebenes Fahrzeug.
• - Motoreinheit, bestehend aus einem Verbrennungsmotor und einem Elektromotor, jeweils zum Antrieb, sowie einer Leistungselektronik, zur Ansteuerung des Elektromotors. Ein Hochvoltspeicher dient zur Energieversorgung des Elektromotors. Das Fahrzeug ist dann ein Hybridfahrzeug.
• - Motoreinheit, bestehend aus einem Elektromotor, zum Antrieb, sowie einer Leistungselektronik, zur Ansteuerung des Elektromotors. Ein Hochvoltspeicher dient zur Energieversorgung des Elektromotors. Das Fahrzeug ist dann ein Elektrofahrzeug.
• - Motoreinheit, bestehend aus einem Elektromotor, zum Antrieb und einem Verbrennungsmotor als range extender, zum Laden eines Hochvoltspeichers, sowie einer Leistungselektronik, zur Ansteuerung des Elektromotors. Der Hochvoltspeicher dient zur Energieversorgung des Elektromotors. Das Fahrzeug ist dann ein Elektrofahrzeug mit range extender.
• - Motoreinheit, bestehend aus einem Elektromotor, zum Antrieb und einer Brennstoffzelle als range extender, zum Laden eines Hochvoltspeichers, sowie einer Leistungselektronik, zur Ansteuerung des Elektromotors. Der Hochvoltspeicher dient zur Energieversorgung des Elektromotors. Das Fahrzeug ist dann ein Brennstoffzellenfahrzeug, auch als FCEV (fuel cell electric vehicle) bezeichnet.
• - Motoreinheit, bestehend aus einem Elektromotor, zum Antrieb, sowie einer Brennstoffzelle, zur Energieversorgung des Elektromotors, sowie einer Leistungselektronik, zur Ansteuerung des Elektromotors. Ein Hochvoltspeicher dient zur Energieversorgung von Verbrauchern, welche einen hohen elektrischen Energiebedarf haben, beispielsweise um eine Hochstartphase der Brennstoffzelle zu überbrücken. Das Fahrzeug ist dann ein Brennstoffzellenfahrzeug, auch als FCEV (fuel cell electric vehicle) bezeichnet.

The vehicle has a high-voltage accumulator and a motor unit. The motor unit is used to drive the vehicle. The engine unit generates waste heat, in particular during operation of the vehicle. Various concepts for the motor unit are suitable, in particular those mentioned below. In all embodiments, the vehicle has a high-voltage storage, which fulfills different functions depending on the specific embodiment:

• - Motor unit, consisting of an internal combustion engine for driving. In this embodiment, the motor unit has no electric motor. A high-voltage storage is used to supply energy to consumers in the vehicle, which have a high electrical energy demand, such as an electric charge air compressor or electric roll stabilization, and in particular require a high operating voltage, ie in particular 48 to 350V. The vehicle is then a purely internal combustion engine driven vehicle.
• - Motor unit, consisting of an internal combustion engine and an electric motor, each for driving, and a power electronics, for controlling the electric motor. One High-voltage accumulator serves to supply power to the electric motor. The vehicle is then a hybrid vehicle.
• - Motor unit, consisting of an electric motor, to the drive, and a power electronics, for controlling the electric motor. A high-voltage accumulator serves to supply power to the electric motor. The vehicle is then an electric vehicle.
• - Motor unit, consisting of an electric motor, the drive and an internal combustion engine as a range extender, for charging a high-voltage accumulator, and a 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, consisting of an electric motor, the drive and a fuel cell as a range extender, for charging a high-voltage accumulator, as well as a 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 FCEV (fuel cell electric vehicle).
• - Motor unit, consisting of an electric motor, to drive, and a fuel cell, for powering the electric motor, and a power electronics, for controlling the electric motor. A high-voltage storage is used to supply energy to consumers who have a high electrical energy requirement, for example to bridge a high-start phase of the fuel cell. The vehicle is then a fuel cell vehicle, also referred to as FCEV (fuel cell electric vehicle).

By "consisting of" is meant, in particular, that the motor unit has only those components that make up the motor unit.

The vehicle further includes an absorption air conditioner having an evaporator, an absorber and a digester. The cooker is integrated into the motor unit. In this case, "integrated" means, in particular, that the cooker is an integral part of the motor unit. Although a coupling of the digester to an engine cooling circuit is fundamentally suitable, "integrated" means, in particular, that such an additional coolant circuit for heat transfer between the engine unit and the digester is dispensed with. The heat transfer takes place directly from the motor unit to the stove. For this purpose, the stove and the motor unit expediently in direct contact.

Particularly preferred is an embodiment in which the vehicle is designed as an electric or hybrid vehicle and in which the motor unit has an electric motor. In such vehicles, the high-voltage storage is used particularly strong, so that its cooling is particularly appropriate.

Particularly preferred is an embodiment of the vehicle as a hybrid vehicle, with an internal combustion engine, in which the digester is integrated. In a further development of this embodiment, the electric motor and / or the power electronics are also connected to the digester for heat exchange. The compound is direct, i. E. the cooker or another cooker is integrated in the electric motor and / or the power electronics, or indirectly via one or more separate coolant circuits. It is essential, in particular, that the cooker be divided into at least one subunit, i. Internal combustion engine, electric motor or power electronics, the engine unit is integrated, the internal combustion engine is particularly preferred.

Alternatively or additionally, the motor unit has a fuel cell, which in particular supplies the electric motor with energy. A fuel cell generates a lot of waste heat during operation, in particular significantly more waste heat than the electric motor. The cooker is then integrated into the fuel cell to use its waste heat to operate the absorption system.

The vehicle further includes a control unit configured to set an HVS cooling operation in which the high-voltage storage is cooled by evaporating a refrigerant in the evaporator, absorbing the refrigerant in an absorber from an absorbing medium, and the refrigerant is released in a digester by the absorption medium is heated with the waste heat of the motor unit. The abbreviation HVS generally stands for high-voltage storage.

In HVS cooling operation, the high-voltage storage is cooled by evaporating a refrigerant in the evaporator, i. it is produced vaporized refrigerant. The refrigerant, more specifically the vaporized refrigerant, is absorbed in an absorber by an absorption medium, i. it is generated absorbed refrigerant. In particular, the vaporized refrigerant is thereby withdrawn from the evaporator, so that further, liquid refrigerant flows in and a continuous cooling is realized. Furthermore, the particular absorbed refrigerant in the digester is released by the absorption medium is heated with the waste heat of the motor unit. The waste heat of the motor unit is thus used as heating heat for heating the absorption medium in the digester. This concept is particularly suitable for a hybrid vehicle, since such has an internal combustion engine which generates particularly large amounts of waste heat during operation, usually more than the electric motor or the power electronics. Depending on the design of the engine unit, the waste heat is generally dissipated by a prime mover, e.g. an internal combustion engine or an electric motor, and / or from an energy store for supplying the engine, e.g. a high-voltage storage or a fuel cell.

A core idea of the invention is, in particular, the waste heat of the motor unit use, especially instead dissipate them via a radiator to the environment. A particular advantage is that due to the use of an absorption air conditioning, the waste heat for cooling, ie for generating a cooling capacity is used and is also used in cooling mode. Especially in summer, when the heat load in the vehicle is particularly high, the waste heat of the motor unit can then efficiently use for air conditioning of the high-voltage storage. No secondary energy needs to be expended. The fuel or the electric energy of the vehicle is advantageously preserved for the driving operation and is not required for the air conditioning of the vehicle. Overall, less CO2 is advantageously produced. This is advantageous above all with regard to the future charging of the energy consumption of an air conditioning, in particular in the context of the WLTP. Namely, the utilization of the waste heat of the engine unit advantageously reduces the proportion of air conditioning in the energy consumption charged in the future.

A significant advantage of the invention is thus in particular that the waste heat of the motor unit is profitably used for the operation of the absorption air conditioning and is converted in this way into cooling power, by means of which the high-voltage storage is cooled. In combination with the integration of the cooker in the motor unit, this use of waste heat is particularly efficient. Appropriately, the stove is therefore arranged as close to the warmest point of the motor unit, so that a maximum of waste heat is available. In operation, the motor unit has a specific core temperature, which is then advantageously used directly on the stove. As a result, in particular a power potential of up to 10 to 20 kW is developed. In contrast, a separate arrangement of the cooker and motor unit would inevitably result in a temperature drop on the way to the cooker, with detrimental effects on the efficiency.

For optimum heat transfer, the cooker is integrated in the motor unit. In other words: a separate circuit for heat transfer is omitted in particular, but the cooker is mounted directly and directly in or on the motor unit. As a result, the transfer of waste heat from the engine unit to the stove is particularly efficient. The stove is expediently integrated as efficiently as possible into an already existing engine cooling concept. In particular, with an additional use of an engine cooling circuit and a cooling field for heat dissipation of the digester is then advantageously positioned so that the stove is primarily supplied with waste heat from a radiator or cooling field, so that waste heat is first supplied to the digester and only then eventually excess heat through the radiator or the cooling field is discharged. An already existing cooler or a cooling field can then advantageously be dimensioned smaller, since a part of the waste heat does not need to be dissipated, but is used to operate the absorption air conditioning.

A particularly suitable integration of the digester is achieved, in particular, by virtue of the fact that the digester is currently not a separate component, but rather is designed and constructed as a fixed part of the motor unit, in particular of the internal combustion engine. In other words, the design and placement of the digester is already taken into account in the design or concept of the motor unit, resulting in a particularly high degree of integration. The cooker is then, for example, a part of an engine block or motor housing of the internal combustion engine or the electric motor, which then has corresponding connections for the refrigerant and possibly the absorption medium. Additionally or alternatively, a corresponding integration is analogously carried out in a housing of the power electronics or the fuel cell. For example, in a fuel cell, the cooker is integrated into a wall or segment of the fuel cell, or a segment of the fuel cell is integrated or generally an integral part of the fuel cell, similar to integration into an engine block. A particularly suitable embodiment assumes that on and / or in a motor unit, in particular in an internal combustion engine, an insulating material, e.g. an insulation pad is attached. The insulation material is used in particular for the thermal and acoustic insulation of the motor unit. In such a motor unit then at least a part of the insulating material is replaced by the digester. In this way, existing motor units can advantageously be converted. A complete redesign is not necessary.

In a particularly expedient development, the evaporator is integrated in the high-voltage accumulator. The concepts for integration described above in connection with the cooker apply mutatis mutandis to the integration of the evaporator. Preferably, the high-voltage accumulator, more precisely a housing, is formed with suitable refrigerant lines, ie the evaporator is formed integrally with the high-voltage accumulator, more precisely its housing. For example, the evaporator is integrated in a bottom plate of the housing, wherein the bottom plate extends over wide areas of the housing and therefore covers many or even all cells of the high-voltage accumulator. Analogous to the use of the core temperature of an internal combustion engine, the evaporator is suitably integrated in such a way that the cooling takes place where the heat is predominant. priority generates the high-voltage storage heat loss to the cells, so that the evaporator is advantageously arranged in intervals between the cells of the high-voltage storage. In a particularly advantageous embodiment, the evaporator is designed such that the refrigerant of the absorption air conditioning system flows around the cells of the high-voltage accumulator. The spaces between the cells form as it were the evaporator. In this case, the refrigerant and the cells, in particular the cell housing, expediently in direct contact with each other. As a result, an advantageous maximum integration of the evaporator is achieved.

The use of waste heat for cooling is made possible in particular due to the use of an absorption air conditioning system. In this respect, the combination of an absorption air conditioner with a cooker integrated in the engine unit and possibly an evaporator integrated into the high-voltage storage unit results in a particularly efficient air conditioning system for cooling the high-voltage storage. An absorption air conditioner is particularly quiet during operation. At the same time, a continuous operation is advantageously possible, i. a continuous cooling or provision of cold. Since the refrigerant circulates constantly during operation of the absorption air conditioner and withdrawn continuously evaporated refrigerant and liquid refrigerant is supplied to the evaporator, a continuous cooling is ensured.

The absorption air conditioner, also referred to as an absorption chiller, is a chiller in which, unlike a compression chiller, a refrigerant is absorbed at low temperature in an absorption medium, also referred to as a solvent, and desorbed at a comparatively higher temperature. The temperature dependence of the physical solubility of two substances is exploited. As a refrigerant, for example, ammonia is used as the absorption medium water, suitably in a hydrogen atmosphere. The use of an absorption air conditioner is particularly simple, since it can be implemented and operated with minimal mechanical effort. In addition, such an absorption air conditioning system is particularly quiet during operation, especially in comparison to a compression air conditioning system. On such is preferably omitted.

An absorption air-conditioning system also has the advantage that it is already at a low temperature gradient of e.g. a few degrees Celsius is operable, the temperature gradient between the digester and the evaporator is measured, which is already advantageous at the start of operation of the absorption air conditioning. Also, continuous operation over wide temperature and temperature gradient ranges is possible. With regard to the operation of the absorption air conditioner is also advantageous self-regulating in the sense that it automatically goes into operation at a corresponding temperature gradient and that the cooling capacity also increases with increasing heating heat. Also, an absorption air conditioner is already at low outdoor temperatures, i. in particular below 0 ° C, operable in which a compression air conditioning system is not operable. As a result, it is possible to achieve cooling of the usually very high-energy-consuming high-voltage accumulator even in winter, especially when cooling by means of ambient air is not possible or sufficient.

In an advantageous embodiment, the motor unit serves as a particularly sensitive heat storage, for storing waste heat in an active state and for providing heat in an inactive state. In this embodiment, therefore, the generation of the waste heat and their use for heating the digester are advantageously separated from each other in time. It is exploited that the engine unit and in particular an engine block and / or a crankcase of the motor unit is made of a certain amount of material, which represents a thermal mass and stores a certain amount of heat. In addition, depending on the design of the motor unit, in particular also oil, i. E. Engine oil, and / or coolant from an engine cooling circuit as a thermal mass. In active state, e.g. when driving the vehicle, the engine unit generates and stores waste heat, i. the material is heated. At a later point in time, the stored waste heat is then removed and fed to the digester so as to remain inactive, i. switched-off state to cool the passenger compartment. Such an inactive state results, for example, in the parking mode of the vehicle or in a vehicle with an engine start-stop system when temporarily held, e.g. at a traffic light.

The above-described concept with the engine unit as a heat storage is basically suitable for any vehicle. However, this embodiment is particularly suitable for a vehicle with an internal combustion engine, in this case hybrid vehicles and electric vehicles with so-called range extender, ie vehicles with electric motor and an internal combustion engine for charging the high-voltage memory. The particular suitability results from the fact that an internal combustion engine is usually designed to be particularly solid and represents a particularly large thermal mass. This can then be bridged correspondingly long periods in the inactive state, for example, 10 to 20min, for example, if after a short-term parking onward. The example of a hybrid vehicle with an electric motor and a Internal combustion engine, the advantage is particularly clear: in alternating operation of the internal combustion engine and the electric motor, ie in mixed operation or alternating operation, a continuous cooling is guaranteed. In phases in which the electric motor is active and the internal combustion engine inactive, waste heat from the still warm combustion engine is used. A phase is for example about 10 minutes long. An air conditioning of the high-voltage storage is then possible without a connection of the internal combustion engine and without consumption of on-board power.

A high-voltage accumulator for a vehicle can basically be operated at an optimum operating temperature, for a high-voltage accumulator based on Li cells, for example at 34 ° C. However, this requires a corresponding cooling. In order to save energy, therefore, the high-voltage storage is operated within a specified temperature interval in order to minimize excessive thermal stress, thus preventing premature aging and to avoid damage, while spending as little energy for cooling. Basically, the lowest possible temperature is preferred, because with increasing temperature, the aging accelerates, i. Degradation of high-voltage storage. But falling below a certain minimum temperature is potentially harmful. The temperature interval is therefore typically characterized by a maximum and in particular a minimum operating temperature, which should not be exceeded or fallen short of. When choosing these two operating temperatures, a compromise is usually made between the lowest possible thermal load and the simplest possible, low-energy air conditioning. This usually results in a maximum operating temperature of 50 ° C. A minimum operating temperature is regularly 0 ° C. Often, in addition to cooling or instead of cooling, the high-voltage accumulator requires less power in order to avoid further heating, as a result of which the driving operation of the vehicle is correspondingly restricted. Such a return of power takes place, for example, actively by controlling the extracted power or passively by self-regulation of the thermally loaded high-voltage storage. The result is in any case a significant limitation and degradation of the customer value functions, i. in particular a reduced acceleration capacity and / or a reduced maximum speed of the vehicle.

When using an absorption air conditioner, special advantages now arise in connection with the cooling of a high-voltage accumulator. Since cooling is advantageously continuously possible, in particular by the use of the motor unit as a thermal storage, and this is used in an efficient way waste heat of the motor unit, which would otherwise be lost, can be implemented particularly advantageous operating strategies for cooling the high-voltage memory. In order to implement a corresponding operating strategy, the control unit controls or regulates the absorption air conditioning in a suitable manner.

In an expedient embodiment, the above-mentioned compromise is advantageously resolved in favor of a reduced maximum operating temperature by the prospective cooling of the high-voltage accumulator. The high-voltage storage has a maximum operating temperature, e.g. 50 ° C, from which cooling is switched on to avoid excessive thermal load. Thus, in particular, acute cooling takes place, i. for specific needs. By "looking ahead" is now understood that the high-voltage storage is already cooled before the maximum operating temperature is reached. Such prospective cooling is advantageously performed when excess waste heat is available, i. when the engine unit is producing waste heat which is currently not needed to operate the absorption air conditioner or beyond its current operation. In other words, if no further cooling power is needed, for example for the passenger compartment or other vehicle component, the excess waste heat will not be wasted, but will be used for anticipatory cooling, i. used for pre-cooling the high-voltage storage. This then represents in particular a cold storage. Due to the predictive cooling, the high-voltage storage on average has a lower temperature than in the case of only acute cooling as described above. The peak temperature, namely the maximum operating temperature, is reached less frequently. The life of the high-voltage storage is thus significantly extended. Of particular advantage is that in so-called hot countries, i. Countries with a high average outside temperature, which is then regularly above the optimum operating temperature of the high-voltage storage. Due to the anticipatory cooling of the high-voltage storage is then kept in particular below the outside temperature. This is not affordable by a conventional low-temperature cooling circuit.

It is particularly expedient if the high-voltage accumulator is cooled in particular in HVS cooling operation, if the high-voltage accumulator exceeds an optimum operating temperature, in particular a temperature of 20 ° C. In other words, the high-voltage accumulator is already cooled from the optimum operating temperature. In particular, the HVS cooling operation is on reaching the optimum operating temperature of the high-voltage storage switched on and switched off when falling below expediently. The optimum operating temperature depends on the type of high-voltage storage, but is in particular below the maximum operating temperature. At the optimum operating temperature, the thermal load of the high-voltage accumulator is particularly low and its operation is particularly efficient. In one embodiment, the optimum operating temperature is 20 ° C, in a high-voltage storage with Li cells 34 ° C.

A forward-looking cooling as described above is also already particularly advantageous below the optimum operating temperature, so that when the high-voltage accumulator is subsequently heated, the optimum operating temperature is then reached or only slightly, e.g. by a few ° C, is exceeded.

Especially in light of the fact that a high absolute power loss regularly occurs in the case of a high-voltage accumulator and is therefore to be cooled only with a correspondingly high energy input, the temperature at which the cooling starts is often chosen to be comparatively high, e.g. at 50 ° C as described above, with an exceeding of the optimum operating temperature is accepted. Lower temperatures, in particular the optimum operating temperature, require a continuous, depending on the weather. continuous cooling, since sufficient cooling with ambient air may not be possible. For example, cooling in the summer may be required by means of an air conditioning system. With the presently used absorption air conditioning, however, an operating strategy with cooling to the optimum operating temperature is easily possible. Due to the waste heat of the motor unit, possibly in combination with the motor unit as a thermal mass, a sufficient amount of cooling capacity is available.

Preferably, the high-voltage storage is continuously cooled. As a result, an optimal temperature of the high-voltage accumulator is advantageously ensured in particular permanently and its thermal load and the associated premature aging are particularly reduced. In this context, "continuous" is understood in particular to mean that the high-voltage accumulator is in continuous operation during operation of the absorption air conditioning system and preferably during operation of the vehicle. is cooled without interruption. In particular, no cyclic or phase-wise cooling takes place. Due to the continuous cooling of the high-voltage storage is preferably kept constant at a certain temperature, preferably the optimum operating temperature.

Fluctuations and thus thermal loads, as in the case of only batchwise cooling, are advantageously avoided. As a result of the continuous cooling, in particular also a forward-looking cooling as described above is realized.

When the vehicle is switched off, the motor unit is switched off and, in particular because of the previous operation, has residual heat. For parking the vehicle, e.g. when parking the engine unit is deactivated, but has in the following time still a certain amount of residual heat, which is suitably used in a Nachkühlbetrieb, for aftercooling of the high-voltage storage in the parked state of the vehicle. For this purpose, the control unit is preferably designed such that a Nachkühlbetrieb is set, in which the high-voltage storage is cooled by means of the residual heat by the stove is heated with the residual heat. In particular, in combination with a use of the motor unit as a thermal mass a particularly simple aftercooling of the high-voltage storage is guaranteed in this way. The aftercooling is advantageously carried out without current, i. no electrical energy is spent directly for aftercooling. Preferably, the after-cooling is also carried out without control, i. that no electronics for controlling or regulating during aftercooling is activated. In particular, the control unit is deactivated after setting the Nachkühlbetriebs and therefore consumes no further power.

During operation of the absorption air conditioning system, the refrigerant and the absorption medium must be circulated. For this purpose, a pump is suitably used, which is arranged for example between the absorber and digester and promotes the absorption medium after the absorption of refrigerant to the digester. By a suitable design of the absorption air conditioning, however, it is also possible to dispense with a pump for circulating, i. The absorption air conditioning is then designed pump-free. 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 structurally particularly simple, low-maintenance and quiet. The thermosyphon effect makes use of the fact that the density of a substance changes with increasing temperature, in particular reduced, so that automatically a circulation occurs solely due to gravity.

In a particularly suitable embodiment, the evaporator is arranged with respect to the digester at a higher point in the vehicle. As a result, a circulation by means of the thermosiphon effect is particularly favored. On a pump can be advantageously dispensed with. Alternatively, a pump is merely used as an alternative. The evaporator is then higher relative to the cooker located so that a circulating pump can be dimensioned smaller or no pump is needed. This is based on the finding that the refrigerant in the digester is warmer than in the evaporator and then rises automatically when the cooker is lower and is circulated.

The evaporator and the digester are connected by means of a line which has a specific line length, which is as short as possible in order to realize the lowest possible heat losses. At the same time, however, the largest possible height difference between the evaporator and the stove is advantageous. Particularly effective has been an embodiment in which the height difference is at least 20cm, i. where the evaporator is at least 20cm 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.

Around the lines, i. To design the refrigerant lines of the absorption air conditioning particularly short, a cooling circuit is connected to the evaporator in one embodiment, also referred to as evaporator cooling circuit or HVS cooling circuit. In this case, the evaporator is not integrated in particular in the high-voltage accumulator, but the high-voltage accumulator is cooled by means of the cooling circuit. As a result, the evaporator can be arranged in particular above the digester and at the same time the high-voltage accumulator as far down in the vehicle as possible, in particular in order to achieve the best possible center of gravity. As a result, the evaporator is advantageously arranged in the vicinity of the digester 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. In particular, optimal cooling of the high-voltage storage possible. Advantageously, the thermosiphon effect is also profitably used even in a high-voltage storage low in the vehicle.

By means of the evaporator in addition to the high-voltage accumulator expediently also the passenger compartment is cooled, generally another vehicle component. A passenger compartment cooling takes place in particular in a passenger compartment cooling operation. This is conveniently adjustable independently of the HVS cooling operation, e.g. via suitable valves in the cooling circuit.

In general, for cooling a plurality of vehicle components, the absorption air conditioning system is expediently designed with a plurality of evaporators or a multi-part evaporator in order, in particular, to fulfill various air conditioning tasks. Various air conditioning tasks are in particular those which are conventionally operated via a low-temperature cooling circuit, e.g. Cooling of electronic components or vehicle seats. The embodiment with a plurality of evaporators or with a multipart evaporator is advantageously combined with a design with several cookers or with a multi-part cooker. As a result, a particularly flexible air conditioning is guaranteed overall.

Preferably, in addition to the motor unit, further heat sources are connected to the absorption air conditioning system. In other words: Preferably, the cooker is thermally connected to at least one further vehicle component, which generates waste heat, for transmitting this waste heat to the cooker. This makes it possible to continue to operate in the absence of waste heat engine unit, the absorption air conditioning and cool the high-voltage storage optimally. Basically, several variants are conceivable. In a first variant, the vehicle component is attached directly to the stove. This variant is particularly suitable for a vehicle component, which is arranged in the vicinity of the motor unit. In a second variant, a circuit with a heat transfer medium is formed, to which the vehicle component and the digester are connected. This variant is particularly suitable for a vehicle component, which is arranged at some distance from the motor unit. In a third variant, the cooker is designed in several parts or several cookers are formed, which are arranged at different locations of the vehicle, in each case at a heat source, namely on the one hand in or on the motor unit and on the other on the vehicle component. A combination of the aforementioned variants is possible and suitable. The concepts mentioned are also suitably used to connect several of the various parts of the motor unit mentioned above.

In a preferred embodiment, the vehicle component is an engine oil circuit or an oil sump of the vehicle. As a result, on the one hand can gain additional heat for the operation of the absorption air conditioning. On the other hand results in this embodiment, a particularly suitable height difference between the digester and the evaporator, since the oil sump is usually very low. An accommodation of the digester generally in the engine oil circuit results in a similar advantageous height difference. However, the arrangement in the oil sump is preferred, since here also a particularly large contact surface is formed and thus a particularly efficient heat transfer is ensured. In addition, when starting the vehicle, the engine oil is the first to warm, so that shortly after starting the engine unit spontaneously heat is available to operate the absorption air conditioning.

Under certain circumstances, the waste heat of the engine unit and possibly other vehicle components is not sufficient to achieve the desired air conditioning means of the absorption air conditioner. Therefore, in an advantageous development, the vehicle component is a heater for the additional generation of heat, ie heating heat for the stove, as needed. In other words, in the case of insufficient waste heat is heated by means of a Zuheizers. As a result, optimal cooling of the high-voltage accumulator is ensured in particular at any time. The auxiliary heater is for example a fuel heater or an electric instantaneous water heater. Particularly suitable, however, is an embodiment in which the vehicle has a heater, which also serves as the heater.

The heater is preferably connected to the stove by means of a separate Zuheizerkreises, which is in particular a water circuit. A heat transfer medium, e.g. Water, which allows a particularly large contact surface, whereby the heat transfer is particularly large. In particular, by means of the Zuheizerkreises and against the background of the integration of the digester in the motor unit heating is also possible without having to integrate the heater also in the motor unit. The Zuheizerkreis is designed spatially limited possible to ensure the lowest possible heat transfer. This is realized in particular by the shortest possible cable lengths for the Zuheizerkreis. In a suitable variant of the heater or possibly the Zuheizerkreis is connected to the motor unit. Due to the integration of the digester into the motor unit, heating of the motor unit at a suitable location may be sufficient.

Furthermore, it is advantageously possible to connect further vehicle components to the Zuheizerkreis and to heat. The heater is then used for several functions. In a suitable embodiment, the oil sump is connected to the heater in order to realize an engine oil heater. In a particularly advantageous embodiment of the heater is designed as a heater, for heating the passenger compartment. In a heating operation, the passenger compartment is then heated by means of the auxiliary heater. For example, a heating heat exchanger is connected to the Zuheizerkreis, which heats air, which is then flowed into the passenger compartment.

In an electric or hybrid vehicle, an electric heater is particularly advantageous. This can namely be profitable even in a loading operation of the vehicle, i. when charging the high-voltage memory, use. In a suitable embodiment, the vehicle is then connected in a charging operation to a power supply, by means of which the high-voltage accumulator is charged and the high-voltage accumulator is cooled by the stove is heated with an electric heater. This prevents the high-voltage accumulator from overheating due to heat generated during charging. In particular, the high-voltage memory can then also be easily used in a fast-charging mode, i. charge at particularly high current. Another advantage results from the particularly quiet operation of the absorption system, because this is also the cooling of the high-voltage storage in the loading mode is particularly silent. Especially with long load times, a noise nuisance from nearby people is advantageously avoided.

For cooling the high-voltage accumulator in the charging operation, a charge cooling operation is expediently set by means of the control unit, in which the electric auxiliary heater is then operated with power from the power supply. The electric heater suitably corresponds to the heater already described above and is in a particularly advantageous variant, a heater. In the charging mode, the vehicle is connected to an external, in particular stationary, power supply, namely the named power supply. These provide a charging current for the high-voltage storage. At the same time, the auxiliary heater is also operated via the power supply, so that operation of the absorption air conditioning system is also realized without waste heat from the motor unit. With the cooling power of the absorption air conditioning system generated in this case, the high-voltage storage is then cooled.

The method is for air conditioning of a vehicle, which is designed as an electric or hybrid vehicle, with a high-voltage storage and with a motor unit that generates waste heat, with an absorption air conditioning, which has an evaporator, an absorber and a cooker, the cooker in the motor unit is integrated, wherein an HVS cooling operation is set, in which the high-voltage storage is cooled by a refrigerant is evaporated in the evaporator, the refrigerant is absorbed in an absorber of an absorption medium and the refrigerant is released in a digester by the absorption medium with the waste heat of the motor unit is heated. Advantageous embodiments and advantages will be apparent from the above statements.

• 1 ein Fahrzeug und
• 2 eine Motoreinheit und eine Absorptionsklimaanlage.

An embodiment of the invention will be explained in more detail with reference to a drawing. In each case schematically show:

• 1 a vehicle and
• 2 a motor unit and an absorption air conditioner.

1 shows a vehicle 2 , which is an electric or hybrid vehicle here and the energy supply for the purpose of driving a high-voltage storage 4 having. This is done by means of an absorption air conditioner 6 cooled, which for heat transfer to a motor unit 8th of the vehicle 2 connected. The engine unit 8th has an electric motor 10 on, to drive the vehicle 2 , For controlling the electric motor 10 In addition, a power electronics not shown in detail is arranged, which in the embodiment of the 1 a part of the motor unit 8th is. In addition, the motor unit 8th an internal combustion engine 12 on. The engine unit 8th , above all the internal combustion engine 12 , generates waste heat, which as heating heat to supply the absorption air conditioning 6 is used. In 1 only the use of waste heat of the internal combustion engine 12 is shown. In a likewise suitable, but not shown variant, waste heat of the electric motor is used alternatively or additionally 10 and / or the power electronics for operating the absorption air conditioning 6 used.

The air conditioning of the high-voltage storage 4 is described below by means of 2 explained in more detail. This shows very schematically the absorption air conditioning 6 and other parts of the vehicle 2 ,

The absorption air conditioner 6 has an evaporator 14 on, in which a refrigerant is evaporated. This will be the environment of the evaporator 14 Heat removed and realized a cooling. This is used in a HVS cooling operation to the high-voltage storage 4 Remove heat and cool it. The vaporized refrigerant is in an absorber 16 absorbed by an absorption medium. As a result, the evaporated refrigerant is the evaporator 14 withdrawn, so that further, liquid refrigerant nachströmt and a continuous cooling is realized. Furthermore, the absorbed refrigerant in a digester 18 released again by heating the absorption medium with heating heat. The heat is supplied by the engine unit 8th provided. Additionally, in 2 the liberated refrigerant still in a condenser 20 cooled and then the evaporator 14 fed again. Overall, the absorption air conditioning system 6 thus two cycles 22 . 24 on which overlap, namely a refrigerant circuit 22 and an absorption medium circuit 24 , Both circuits 22, 24 overlap starting from the absorber 16 in which refrigerant and absorption medium are mixed, to the digester 18 in which refrigerant and absorption medium are separated from each other.

To achieve optimal heat transfer is the cooker 18 present in the motor unit 8th integrated, in particular instead of conventional insulation. This is to heat the stove 18 the core temperature of the motor unit 8th accessible. The engine unit 8th is also used as a thermal mass, so that waste heat is stored for example in the crankcase or in the engine block and is also available at a later date. In particular, even then heating, ie waste heat available when the engine unit 8th in an inactive state, ie switched off.

In addition, the engine unit 8th an oil sump 26 on and the cooker 18 is in the illustrated embodiment example in the motor unit 8th integrated that the cooker 18 also the oil sump 26 Waste heat takes. This is the cooker 18 also in the vehicle 2 installed particularly deep, so that to circulate the refrigerant and the absorption medium in the two circuits 22 . 24 is dispensed with a pump. Instead, between the evaporator 14 and the cooker 18 formed a height difference of at least 20cm and the circulation is carried out solely by means of the thermosiphon effect.

Furthermore, in the illustrated embodiment, the evaporator 14 for a particularly optimal cooling in the high-voltage accumulator 4 integrated. In an alternative, not shown, is the evaporator 14 a separate component and the high-voltage storage 4 attached, for direct cooling, or via a HVS refrigeration cycle to the high-voltage storage 4 tethered. The embodiment with an additional, separate HVS cooling circuit is particularly suitable for forming a suitable height difference between the evaporator 14 and cooker 18 , while at the same time the lowest possible location of the high-voltage storage 4 in the vehicle 2 ,

The vehicle 2 still has a heater 28 on, which is an electric heater in the embodiment shown. Alternatively or additionally, the heater is 28 a heater, which also for heating an unspecified passenger compartment of the vehicle 2 is used. The heater 28 is about a small Zuheizerkreis 30 with the cooker 18 connected to provide it with heating, if the engine unit 8th No or only insufficiently generated waste heat. Also the engine unit 8th itself is to the Zuheizerkreis 30 connected, so that the motor unit 8th can be heated in the sense of engine heating or preheating. In a variant, not shown, additionally or alternatively to the motor unit 8th the oil sump 26 with the heater 28 connected to realize an engine oil heater.

The absorption air conditioner 6 and in particular also some or all of the remaining vehicle components are provided by a control unit 32 controlled, which, for example, a central control unit 32 of the vehicle 2 is. The control unit 32 controls or regulates the absorption air conditioner 6 to implement various operating strategies for cooling the high-voltage memory. Some preferred operating strategies are explained in more detail below.

In an operating strategy is the high-voltage storage 4 anticipatory cooled. The high-voltage storage 4 regularly has a maximum operating temperature, eg 50 ° C, from which a cooling is turned on to avoid excessive thermal stress. For this purpose, in particular, an acute cooling takes place. For predictive cooling, the high-voltage battery 4 already cooled before the maximum operating temperature is reached. For this purpose, in particular excess waste heat of the motor unit 8th used, which currently not for the operation of the absorption air conditioner 6 is needed, that is, if no further cooling power is needed, for example, for the passenger compartment or another vehicle component. As a result, the maximum operating temperature is reached less frequently and the life of the high-voltage memory 4 significantly extended.

Alternatively or additionally, the high-voltage storage 4 cooled, if this has a temperature of 20 ° C, ie already cooled from a temperature of 20 ° C.

For this purpose, the HVS cooling operation when reaching a temperature of the high-voltage storage 4 turned on by just that 20 ° C.

Alternatively or additionally, the high-voltage storage 4 continuously cooled and thus permanently an optimum temperature of the high-voltage accumulator 4 guaranteed. This is the high-voltage storage 4 especially kept constant at a certain temperature. Fluctuations and thus thermal loads, as in the case of only batchwise cooling, are advantageously avoided.

Another operating strategy results when parking the vehicle 2 , ie outside driving, for example when parking. The engine unit 8th is then switched off, but has a residual heat due to the previous operation. This is used in a post-cooling operation for aftercooling of the high-voltage storage 4 in the parked state of the vehicle 2 , This is what the control unit provides 32 the absorption air conditioner 6 such a thing that the cooker 18 is heated with the residual heat. In particular in combination with a use of the motor unit 8th As a thermal mass is a particularly effective aftercooling of the high-voltage storage in this way 4 guaranteed. The after-cooling takes place, in particular, without current, ie no electrical energy is expended for the after-cooling. Furthermore, the aftercooling takes place in particular also without regulation, ie that no electronics for controlling or regulating during aftercooling is activated. This is the control unit 32 after setting the postcooling mode then deactivated and then consumes no further power.

In another operating strategy, the electric heater becomes 28 profitable in a loading operation of the vehicle 2 ie when charging the high-voltage memory 4 used. In charging mode is the vehicle 2 connected to a power supply, not shown, by means of which the high-voltage storage 4 is charged. This is then cooled by the cooker 18 with an electric heater 28 is heated. This is what the control unit provides 32 a charge cooling operation.

LIST OF REFERENCE NUMBERS

2

vehicle

4

High-voltage battery

6

Absorption air conditioning

8th

motor unit

10

electric motor

12

internal combustion engine

14

Evaporator

16

absorber

18

Stove

20

capacitor

22

Refrigerant circulation

24

Absorption medium circuit

26

oil sump

28

Heaters

30

Zuheizerkreis

32

control unit

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102008039908 A1 [0004]

Claims (17)

Vehicle (2) with a high-voltage accumulator (4) and with a motor unit (8) which generates waste heat, with an absorption air conditioning system (6) having an evaporator (14), an absorber (16) and a cooker (18), wherein the cooker (18) is integrated with the motor unit (8), and with a control unit (32) which is adapted to set an HVS cooling operation, in which the high-voltage accumulator (4) is cooled by evaporating a refrigerant in the evaporator (14), - The refrigerant in an absorber (16) is absorbed by an absorption medium and - The refrigerant is released in a digester (18) by the absorption medium with the waste heat of the motor unit (8) is heated. Vehicle (2) according to the preceding claim, characterized in that the evaporator (14) is integrated in the high-voltage accumulator (4). Vehicle (2) according to one of the preceding claims, characterized in that the motor unit (8) serves as a heat storage, 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 control unit (32) is designed such that the high-voltage accumulator (4) is cooled in particular with excess waste heat in a forward-looking manner. Vehicle (2) according to one of the preceding claims, characterized in that the control unit (32) is designed such that the high-voltage accumulator (4) is cooled, if it exceeds the optimum operating temperature, in particular a temperature of 20 ° C. Vehicle (2) according to one of the preceding claims, characterized in that the control unit (32) is designed such that the high-voltage accumulator (4) is cooled continuously. Vehicle (2) according to one of the preceding claims, characterized in that when the same the engine unit (8) is switched off and has a residual heat and that the control unit (32) is designed such that a Nachkühlbetrieb is set, in which the high-voltage storage ( 4) is cooled by means of the residual heat by the cooker (18) is heated with the residual heat. Vehicle (2) according to one of the preceding claims, characterized in that the absorption air conditioning system (6) is designed such that the refrigerant and / or the absorption medium are circulated in operation only by means of the thermosyphon effect. Vehicle (2) according to one of the preceding claims, characterized in that the evaporator (14) with respect to the digester (18) is arranged at a higher point. (20 cm) Vehicle (2) according to one of the preceding claims, characterized in that the cooker (18) is thermally connected to at least one further vehicle component (26, 28), which generates waste heat, for transmitting this waste heat to the digester (18). Vehicle (2) according to the preceding claim, characterized in that the vehicle component (26, 28) is an engine oil circuit or an oil sump (26). Vehicle (2) according to one of the two preceding claims, characterized in that the vehicle component (26, 28) is a heater (28) for additionally generating additional heat for the digester (18). Vehicle (2) according to one of the preceding claims, characterized in that it is connected in a loading operation to a power supply by means of which the high-voltage accumulator (4) is charged and that the high-voltage accumulator (4) is cooled by the cooker (18) an electric heater (28) is heated. Vehicle (2) according to one of the preceding claims, characterized in that this is designed as an electric or hybrid vehicle and that the motor unit (8) comprises an electric motor. Vehicle (2) according to one of the preceding claims, characterized in that the motor unit (8) comprises 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 absorption air conditioning system (6) with a plurality of evaporators (14) or a multi-part evaporator (14) is designed to meet in particular various air conditioning tasks. Method for air conditioning of a vehicle (2), which is designed as an electric or hybrid vehicle, with a high-voltage accumulator (4) and with a motor unit (8), which generates waste heat, with an absorption air conditioner (6) having an evaporator (14), an absorber (16) and a digester (18), the digester (18) being integrated with the engine unit (8), adjusting HVS cooling operation in which - the high-voltage accumulator (4) is cooled by evaporating a refrigerant in the evaporator (14), - the refrigerant is absorbed by an absorption medium in an absorber (16) and - the refrigerant is released in a digester (18) by the absorption medium with the waste heat of the motor unit (8) is heated.

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