motor vehicle and air conditioning system

Abstract

A motor vehicle with at least one passenger compartment is described, wherein the passenger compartment is air-conditioned by means of an air conditioning system. The air conditioning system has at least one exhaust air opening through which exhaust air can flow out of the passenger compartment. In addition, at least one supply air opening is provided through which fresh air can flow into the passenger compartment. Furthermore, at least one heat exchanger is present, which is configured to extract heat energy from the exhaust air flowing out through the exhaust air opening and transfer it to the fresh air flowing in through the supply air opening.

Description

This document describes a motor vehicle and an air conditioning system. Motor vehicles and air conditioning systems of the type mentioned above are known in the prior art. In vehicles with internal combustion engines, the passenger compartment is typically heated by utilizing the engine's waste heat. During the operation of an internal combustion engine, heat is generated, primarily through combustion processes in the cylinder and friction losses in moving components. Approximately one-third of the fuel's total energy is converted into heat in internal combustion engines. This heat is dissipated via a cooling system, which typically includes a coolant circuit. Integrated into this circuit is a heat exchanger, commonly referred to as a heater core or heating element. This heating element is located in the vehicle's ventilation system and transfers the absorbed heat to the passenger compartment via an airflow. The heating output is controlled by mechanical or electronic control valves that vary the coolant flow through the heating element. Alternatively or additionally, electric auxiliary heaters can be used in certain motor vehicles, particularly in diesel engines or hybrid vehicles with reduced engine operation. These auxiliary heaters are typically based on electric resistance heating elements or fuel-powered auxiliary heaters. Unlike vehicles with combustion engines, electric vehicles do not have a direct waste heat source with a sufficiently high energy output to heat the passenger compartment. Since the electric powertrain operates much more efficiently than a combustion engine, only minimal heat losses occur, which cannot readily be used for heating the passenger compartment. The need to provide heating energy solely through electrical energy from the traction battery directly reduces the vehicle's available range. Especially in cold environments, the energy consumption of the heating system can account for a significant portion of the vehicle's total energy demand. Additionally, thermodynamic challenges exist, as particularly at low ambient temperatures, large temperature differences arise between the interior and the outside environment, resulting in increased heat loss through vehicle windows, body panels, and air leaks. At the same time, comfort requirements must be met, such as rapid warming of the interior after entry. To make heating the passenger compartment of electric vehicles more efficient, various technical approaches are known. One widespread measure is the use of heat pump systems, which absorb heat from the ambient air or from thermal losses within the vehicle and transfer it to the passenger compartment with a higher efficiency than conventional electric heating elements. Heat pumps thus enable a significant reduction in energy consumption compared to purely electric heating systems. Additionally, seat and steering wheel heaters are available, which allow for targeted heat delivery to the occupants' bodies. Since these heating methods, through direct heat contact, are more efficient than heating the interior air over a large volume, they contribute to reducing overall energy consumption. From JP 29 55 899 A, an internal heat exchanger for a motor vehicle is known, which is arranged in a first compartment and has an outside air inlet for drawing in air from outside the vehicle and an air outlet for blowing air into the vehicle and exchanging heat with the air introduced into the first compartment. An external heat exchanger is provided, which is arranged in a second compartment and has an outside air inlet for drawing in air from outside the vehicle and an air outlet for exhausting air outside the vehicle, and performs heat exchange with the air introduced into the second compartment. A compressor is provided, which is connected to one of two refrigerant lines, to circulate a refrigerant between the internal and external heat exchangers and to compress the refrigerant. Another compressor is provided on the other side of the refrigerant lines.A pressure reducing device serves to reduce the pressure of the refrigerant flowing between the internal heat exchanger and the external heat exchanger. The first chamber, containing the internal heat exchanger, is located in front of the vehicle compartment. A second chamber, containing the heat exchanger, is located behind the vehicle compartment, along with the external heat exchanger. This second chamber and the vehicle compartment can communicate via a closable ventilation opening. The external air inlet of the first chamber, the external air inlet opening, and the air outlet opening of the second chamber are each closable. The compressor is located in a third chamber, separate from the first chamber, the second chamber, and the passenger compartment.The third chamber is equipped with an opening and closing cooling air inlet for receiving compressor cooling air from outside the vehicle and an opening and closing heat outlet for discharging the air heated in the third chamber outside the vehicle. The task therefore is to further develop motor vehicles and air conditioning systems in such a way that the air conditioning of passenger compartments can be done in a more energy-efficient manner. The problem is solved by a motor vehicle according to claim 1 and an air conditioning system according to dependent claim 14. Further embodiments and developments are the subject of the dependent claims. The following describes a motor vehicle with at least one passenger compartment, the passenger compartment being air-conditioned by an air conditioning system. The air conditioning system has at least one exhaust air opening through which exhaust air can flow out of the passenger compartment. In addition, at least one supply air opening is provided through which fresh air can flow into the passenger compartment. Furthermore, at least one heat exchanger is present, which is configured to extract heat energy from the exhaust air flowing out through the exhaust air opening and transfer it to the supply air flowing in through the supply air opening. The passenger cabin defines the interior space where passengers and the driver are located. It is designed to offer both comfort and functionality. The cabin typically includes a dashboard area with gauges and controls to ensure both safety and ease of use for the vehicle. The climate control system is a key component for maintaining comfort within the passenger cabin. It regulates the temperature and, depending on the design, humidity in the vehicle interior, thus creating a pleasant environment regardless of external weather conditions. The air conditioning system can include fans and exhaust systems. The fan can have variable speed settings. Furthermore, sensors can be incorporated to enable thermostat control and to detect indoor and outdoor air quality, ensuring optimal settings and air distribution. The at least one exhaust vent is positioned to ensure effective removal of stale air from the passenger compartment. It is located in a position that guarantees good airflow of fresh air within the passenger cabin while simultaneously minimizing noise and drafts from the escaping exhaust air. The exhaust vent also serves to remove odors from the passenger cabin. By continuously removing stale air and the resulting humidity from damp clothing, perspiration, and breath, the at least one exhaust vent helps prevent the formation of mold spores. The at least one air intake vent plays an equally important role by drawing fresh air from the surrounding environment into the passenger compartment. Typically, several air intake vents are present, usually located in the dashboard. They are designed to allow the airflow to circulate smoothly and evenly throughout the vehicle, helping to prevent drafts inside. These vents ensure that the interior is constantly supplied with oxygen-rich air, which improves air quality and provides comfortable temperature regulation. The placement and design of the air intake vents are crucial for the efficient operation of the air conditioning system. At least one air intake opening can be part of a ventilation system responsible for circulating air through the interior of the vehicle. It typically consists of a variety of moving parts, such as fans or blowers, that control the airflow, and nozzles that distribute the air to different areas of the passenger compartment. The heat exchanger is responsible for transferring heat between the exhaust air and the supply air flowing through the vehicle interior. During heating operation, the heat exchanger absorbs heat from the exhaust air and transfers it to the supply air. In cooling mode, the process is reversed: cold exhaust air is heated by the warm supply air via the heat exchanger, which in turn cools the supply air. The heat exchanger is designed as an air-to-air heat exchanger. An air-to-air heat exchanger is a device for transferring heat between two air streams without them mixing. The basic structure of an air-to-air heat exchanger typically includes a housing containing a heat-conducting element, such as a plate or tube structure made of metal or plastic. This element physically separates the two air streams of exhaust air and supply air, but allows heat exchange through conduction and transfer. Various designs are possible. In a plate heat exchanger, air flows through alternately arranged channels separated by heat-conducting plates. Heat transfer occurs through the plate walls, and this can be based on a counterflow, crossflow, or mixed-flow principle. This design is characterized by its compact form and high efficiency, as large heat transfer surfaces can be achieved. A rotary heat exchanger consists of a rotating storage mass through which exhaust and supply air alternately flow. The storage mass absorbs heat from the warmer airflow and transfers it to the cooler airflow as it rotates. This design enables a particularly high heat recovery rate and, depending on the material of the storage mass, can also transfer moisture between the airflows. Another design is the heat tube heat exchanger, which consists of parallel heat tubes filled with a phase change medium. Through evaporation and condensation of the medium within the tubes, heat can be transferred very efficiently from the warm to the cold air stream. A vehicle equipped with this system can use significantly less energy to heat or cool the passenger compartment than conventional vehicles, thanks to energy recovery via the heat exchanger. In a first further embodiment, it may be provided that the motor vehicle is equipped with an electric drive which includes at least one traction battery and at least one electric drive motor. In electric vehicles, the overall performance and range are particularly improved by reducing the energy required for air conditioning the passenger compartment, since electric vehicles produce little waste heat in the drivetrain. In a further, more advanced embodiment, the heat exchanger may be designed to extract heat energy from the supply air flowing in through the supply air opening and to supply it to the exhaust air flowing out through the exhaust air opening. In a further, more advanced embodiment, it may be provided that at least one exhaust air opening is arranged at a rear end of the passenger cabin. This ensures a pleasant, draft-free and turbulence-free airflow in the passenger cabin. In a further embodiment, it can be provided that the exhaust air opening and / or supply air opening has at least one air duct, wherein the air duct is connected to the heat exchanger. This allows at least one air intake opening and at least one exhaust air opening to be placed at different locations on the vehicle and for the intake air or exhaust air to be supplied to the heat exchanger. In a further, more advanced design, it may be provided that the air duct is thermally insulated. This reduces heat loss during transport and increases efficiency. In a further, more advanced embodiment, it can be provided that the heat exchanger has an efficiency of 90% or more. The efficiency of a heat exchanger is a measure of the effectiveness of heat transfer between two fluid flows and indicates what proportion of the maximum possible heat transfer is actually achieved. It is defined as the ratio of the actual amount of heat transferred to the maximum theoretically possible amount of heat under ideal conditions. In heat exchangers with an efficiency of at least 90%, it is ensured that the greatest possible proportion of usable energy is extracted from the air streams. In a further, more advanced design, it may be provided that the air conditioning system includes a heat pump. Integrating a heat pump into the air conditioning system further increases efficiency. The heat pump can provide both heating and cooling. It usually operates with a compressor. In cold temperatures, the heat pump draws energy from the ambient air and transfers it into the vehicle interior. In a further, more advanced design, it may be provided that the passenger cabin is thermally insulated. A thermally insulated passenger cabin further reduces the energy requirements of the air conditioning system. In a further, more advanced embodiment, it may be provided that the heat exchanger is arranged centrally to the passenger cabin. The central arrangement of the heat exchanger within the cabin enables an even pressure distribution of the supply and exhaust air flows. In a further, more advanced embodiment, it can be provided that the exhaust air from the heat exchanger is discharged towards the rear of a vehicle and into the surrounding environment. This configuration and placement of at least one exhaust vent contributes to optimized air circulation. In a further, more advanced design, it may be provided that the supply air is drawn from the surrounding area in front of the passenger cabin. This configuration and placement of at least one air inlet contributes to optimized air circulation. In a further, more advanced design, it may be provided that the passenger cabin has at least one seat for at least one driver and / or at least one passenger. A first independent item concerns an air conditioning system of a motor vehicle of the type described above. Further features and details will become apparent from the following description, in which – possibly with reference to the drawing – at least one embodiment is described in detail. The features described and / or illustrated, either individually or in any meaningful combination, constitute the subject matter, possibly also independently of the claims, and may in particular also be the subject matter of one or more separate applications. Identical, similar, and / or functionally equivalent parts are designated with the same reference numerals. It schematically shows the only figure, a top view of a motor vehicle 2. The motor vehicle 2 has a front 2.1 and a rear 2.2. The motor vehicle 2 also has a passenger cabin 4 with a front section 4.1 and a rear section 4.2. The motor vehicle 2.1 is an electric vehicle with an electric drive 6, comprising an electric drive motor 6.1 and a traction battery 6.2. Such an electric drive 6 produces very little waste heat, which is insufficient to air-condition the passenger cabin 4 at colder ambient temperatures. For the climate control of passenger cabin 4, an air conditioning system 8 is provided, the central component of which is a heat exchanger 10. Supply air 12.1 is introduced into the front of passenger cabin 4 via an air inlet 12. An exhaust air inlet 14 in the rear of passenger cabin 4 ensures that used exhaust air 14.1 is expelled from the passenger cabin 4. The supply air inlet 12 and the exhaust air inlet 14 are connected to the heat exchanger 10 via corresponding air ducts 12.2 and 14.2, so that thermal energy can be exchanged between the supply air 12.1 and the exhaust air 14.1 via the heat exchanger 10 as needed, i.e., for cooling or heating. The respective air ducts 12.2 and 14.2 are each thermally insulated to prevent heat loss during the transport of the supply air 12.1 and the exhaust air 14.1 from the corresponding opening 12.14 to the heat exchanger 10. Depending on the operating mode, the heat exchanger 10 extracts energy from one airflow and transfers it to another. When the outside temperature is colder than the desired temperature in the passenger cabin 4, energy is extracted from the warmed exhaust air 14.1 and added to the cooler supply air 12.1 via the heat exchanger 10. This warms the supply air 12.1. Conversely, when the outside temperature is warmer than the desired temperature in the passenger cabin 4, energy is extracted from the supply air 12.1 and added to the exhaust air 14.1 via the heat exchanger 10. A heat pump 16 is installed upstream of the heat exchanger 10. This heat pump heats or cools ambient air from outside the vehicle 2, which is drawn in via a fresh air duct 18 in area 4.1 in front of the passenger compartment 4. In this way, a desired temperature can first be reached in the passenger compartment 4, and subsequently, energy losses due to suboptimal heat exchange at the heat exchanger 10 can be compensated for. After heat has been extracted or added to the exhaust air 14.1, it is discharged via an exhaust air duct 20 that terminates in the area of ​​the rear of the vehicle 2.2. Although the subject matter has been illustrated and explained in detail by means of exemplary embodiments, the invention is not limited by the disclosed examples, and other variations can be derived from them by a person skilled in the art. It is therefore clear that a multitude of possible variations exist. It is also clear that the exemplary embodiments mentioned are merely examples and are not to be interpreted in any way as limiting, for example, the scope of protection, the possible applications, or the configuration of the invention.Rather, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete terms, whereby the person skilled in the art, with knowledge of the disclosed inventive concept, can make various changes, for example with regard to the function or the arrangement of individual elements mentioned in an exemplary embodiment, without leaving the scope of protection defined by the claims and their legal equivalents, such as a further explanation in the description. Reference symbol list 2 Motor vehicle 2.1 Vehicle front 2.2 Vehicle rear 4 Passenger cabin 4.1 Area in front of the passenger cabin 4.2 Rear of the passenger cabin 6 Electric drive 6.1 Electric drive motor 6.2 Traction battery 8 Air conditioning system 10 Heat exchanger 12 Air intake 12.1 Air intake 12.2 Air duct 14 Exhaust vent 14.1 Exhaust air 14.2 Air duct 16 Heat pump 18 Fresh air duct 20 Exhaust air duct QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature JP 29 55 899 A

[0010]

Claims

Motor vehicle (2) with at least one passenger cabin (4), wherein the passenger cabin (4) is air-conditioned by means of an air conditioning system (8), wherein the air conditioning system (8) has at least one exhaust air opening (14) through which exhaust air (14.1) can flow out of the passenger cabin (4), wherein at least one supply air opening (12) is provided through which supply air (12.1) can flow into the passenger cabin (4), wherein at least one heat exchanger (10) is provided which is configured to extract heat energy from the exhaust air (14.1) flowing out through the at least one exhaust air opening (14) and to supply it to the supply air (12.1) flowing in through the at least one supply air opening (12). Motor vehicle (2) according to claim 1 , with an electric drive (6) having at least one traction battery (6.2) and at least one electric drive motor (6.1). Motor vehicle (2) according to claim 1 or 2, wherein the at least one heat exchanger (10) is configured to extract heat energy from the supply air (12.1) flowing in through the at least one supply air opening (12) and to supply it to the exhaust air (14.1) flowing out through the at least one exhaust air opening (14). Motor vehicle (2) according to one of the preceding claims, wherein at least one exhaust opening (14) is arranged at a rear end (4.2) of the passenger cabin (4). Motor vehicle (2) according to one of the preceding claims, wherein the exhaust air opening (14) and / or the air supply opening (12) have at least one air duct (14.2, 12.2), wherein the air duct (14.2, 12.2) is connected to the at least one heat exchanger (10). Motor vehicle (2) according to claim 5, wherein the at least one air duct (14.2, 12.2) is thermally insulated. Motor vehicle (2) according to one of the preceding claims, wherein the at least one heat exchanger (10) has an efficiency of 90% or more. Motor vehicle (2) according to one of the preceding claims, wherein the air conditioning system (8) comprises a heat pump (16). Motor vehicle (2) according to one of the preceding claims, wherein the passenger cabin (4) is thermally insulated. Motor vehicle (2) according to one of the preceding claims, wherein the at least one heat exchanger (10) is arranged centrally to the passenger cabin (4).

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