DE102020104150A1 - Motor vehicle with electric drive - Google Patents

Abstract

Motor vehicle with electric drive, comprising at least one battery supplying one or more electric motors driving the vehicle with an associated battery cooling circuit (5) and a passenger cell (2) with a floor (3), the battery cooling circuit (5) via a heat exchanger device (7) is coupled to a heating circuit (22) of an underfloor heating system (6).

Description

The invention relates to a motor vehicle with an electric drive, comprising at least one battery supplying one or more electric motors driving the vehicle with an associated battery cooling circuit, as well as a passenger cell with a floor.

An increasing number of modern motor vehicles are purely electric, which means that only electrical energy is used to drive the vehicle. For this purpose, one or more electric motors are installed on the vehicle side, via which the drive takes place. This or these electric motors are fed from a correspondingly large battery that has to be charged from time to time. On the one hand, this takes place recuperatively while driving, which means that the electric motors are switched as generators during braking or deceleration processes and this recuperates energy that is pushed into the battery. In addition, the battery is of course also charged when the vehicle is stationary, i.e. when the vehicle is parked overnight or during a charging stop. This is preferably done using so-called fast charging systems, in which the charging process takes place with high power in a relatively short time.

The battery heats up during operation of the vehicle, but also during such charging processes, in particular during rapid charging. In order to cool the battery so that it can be prevented from becoming too hot, the battery is assigned a battery cooling circuit in which a cooling fluid circulates that is thermally coupled to the battery so that heat generated on the battery side is transferred to the cooling fluid and dissipated can.

The cooling fluid then emits the absorbed heat to a suitable heat dissipation structure such as corresponding cooling fins or the like, via which the waste heat is finally dissipated.

the end US 2017/0106724 A1 an electrically powered motor vehicle is known in which the battery cooling circuit is in two parts, that is, has two loops. A first cycle loop runs in a known manner to a heat release structure, where the waste heat is released to the outside. A second circuit loop runs to a fan device of an interior heater, via which the warm air, which is given off by the heated cooling fluid, is blown into the vehicle interior. It is possible to switch between the two cooling circuit loops as required. In particular, the second cooling circuit serves to additionally dissipate waste heat, which cannot be dissipated via the first cooling circuit loop because the battery is heated too much, via the second circuit. It is true that part of the waste heat can also be used in this way. However, the design of the battery cooling circuit with the two loops directly connected to the battery and the integration or coupling to an additional fan etc. is complex. A supply of hot air via a fan is also sometimes perceived as annoying.

The invention is based on the problem of specifying a motor vehicle which is improved in comparison.

To solve this problem, it is provided according to the invention in a motor vehicle of the type mentioned at the outset that the battery cooling circuit is coupled to a heating circuit of an underfloor heating system via a heat exchanger device.

According to the invention, underfloor heating is provided on the vehicle side, which heats the passenger compartment, that is to say the vehicle interior, using waste heat accumulating on the battery side. For this purpose, the underfloor heating is integrated into a heating circuit, which in turn is thermally coupled to the battery cooling circuit via a heat exchanger device. As described, heat generated on the battery side is dissipated via the battery cooling circuit for cooling purposes, i.e. the cooling fluid, when it circulates through the circuit or the cooling circuit line, absorbs and dissipates heat as it flows through the battery. This cooling circuit is now coupled to a heat exchanger to which the heating circuit is also coupled. In the heat exchanger, there is now a heat transfer from the warm cooling fluid in the cooling circuit of the battery to the heating fluid in the heating circuit of the underfloor heating. This means that the heating fluid circulating in the heating circuit is heated via the heat exchanger. Since this heating fluid then flows through the underfloor heating or the areas of the underfloor heating that are arranged on the floor in the passenger cell, a corresponding heat transfer to the passenger cell takes place, whereby the temperature control is very pleasant, since the underfloor heating provides constant, not with a fan, or draft associated heat release is possible.

In addition, the integration of the underfloor heating and its thermal coupling to the battery cooling circuit also makes it possible to control the temperature of the passenger cell over a large area, as the underfloor heating can be installed in correspondingly large areas within the passenger cell or on the floor side, unlike the previously known fan connections that usually only have one or very few, locally distributed and fixed air vents.

Overall, the motor vehicle according to the invention offers a very useful additional use of the waste heat accumulating on the battery side, combined with pleasant air conditioning comfort via underfloor heating.

In a further development of the invention, the battery circuit and the heating circuit expediently each have a heating or cooling fluid circulating therein and conveyed by a pump, that is, a pump is integrated in each circuit that circulates the heating or cooling fluid. Each pump can be controlled either via a separate or a common control device, so that the pumping operation can be precisely controlled as required. This means that if the battery heats up during rapid charging, for example, the pump on the battery circuit side is activated once a certain threshold temperature has been reached, and the cooling fluid is conveyed for cooling. In the event that the interior temperature is not to be controlled via the underfloor heating, the pump of the heating circuit remains switched off, which means that the resulting heat is dissipated to the environment as before. If, however, there is a heating request on the part of a person in the vehicle interior, or possibly in the form of a parking heater, the control device also controls the pump of the heating circuit so that the heating fluid there is circulated and the heat of the cooling circuit fluid is transferred to the heating circuit fluid and via the underfloor heating Tempering can be used.

A particularly advantageous development of the invention provides at least one switchable valve device integrated in the battery cooling circuit, via which the cooling fluid can be fed either to the heat exchanger device or to a heat dissipation structure integrated in the battery cooling circuit. This valve device is used to guide the cooling fluid on the cooling circuit side, depending on requirements, either to the heat dissipation structure leading to the environment, i.e. the cooling rib block etc., namely when no underfloor heating operation is desired, or to guide it to the heat exchanger device, where the heat is then transferred to the heating fluid, if underfloor heating is required. This means that the heat exchanger is only integrated or loaded when heating is actually required, otherwise the cooling fluid is inevitably guided over the heat dissipation or cooling fin structure.

The underfloor heating is laid on the floor, i.e. over a relatively large area. The floor in the vehicle is usually divided into a front area in front of the two front seats and a rear area in front of the rear seats. Underfloor heating can be provided in all of these areas. It is conceivable to implement only one heating circuit, that is to say to lay a fluid line over the entire floor area in the front and, if given, also in the rear area. Alternatively, it is conceivable to implement the heating circuit via two or more separate sub-circuits which are assigned to different areas within the passenger cell and to which the heating fluid can be supplied separately, controllable via at least one switchable valve device. In this case, for example, three or four sub-circuits are provided. A first and a second in front of the two front seats in the respective footwell, a third in front of a common rear seat bench or a third and fourth in front of a rear seat in the respective footwell there. Each sub-circuit can be supplied separately with cooling fluid, which means that each passenger compartment area can also be temperature-controlled separately. This means that the driver can set a different underfloor heating temperature than the front passenger or a person in the rear. The temperature is set in a simple manner using a corresponding operating element, for example a corresponding operating menu on a display arranged in the area of the center console or the like or on corresponding setting buttons in the front area or in the rear area, where touch displays and the like can of course also be provided . As a result, zone-by-zone heating, i.e. zone air-conditioning, can be implemented in this way. This air conditioning, be it in the entire interior or only in zones, can either be set by people in the vehicle, with one or more people often still in the vehicle, for example, during a fast charging process. Alternatively, the temperature control can also take place in the manner of a parking heater, namely when, for example, during a fast charging process, the people have left the vehicle to take a break, but want the vehicle to have a pleasant temperature when they return.

As described, there is the possibility that the battery cooling circuit and the heating circuit are each assigned a separate control device via which the respective pump and, if provided, the respective valve device etc. can be controlled. This means that any controllable element that is integrated in the respective cooling or heating circuit can be controlled via a corresponding control device assigned to the circuit. Alternatively, it is also conceivable that a common control device is assigned, via which the corresponding controllable components of both circuits are controlled. Regardless of how concretely the configuration with one or more control devices is, the or each control device naturally communicates with corresponding components external to the circuit in order to acquire and control corresponding control commands to implement, for example a request to switch on the underfloor heating, or a desired temperature control setpoint, etc., as well as a corresponding actual temperature value of the battery temperature, depending on which the battery cooling is then switched on when a threshold value is reached, etc. This means that in In this case, the or each control device is set up to control the respective pump and / or the valve devices as a function of the actual temperature of the battery. Because only when the actual temperature exceeds a threshold temperature is there too much heat in the battery that has to be dissipated, so that the battery cooling is only switched on afterwards, as is the basic possibility of operating the underfloor heating in addition .

The or each control device can furthermore be set up to control the respective pump and / or the valve device as a function of a user-definable temperature value defining the target temperature in the passenger compartment and / or a user-definable heating start time or heating duration of the underfloor heating. The user, for example the driver, consequently interacts with the underfloor heating system by being able to set certain operating parameters, for example via a touch display menu. For example, he can set the target temperature in the passenger compartment via a corresponding temperature value that is to be reached via the underfloor heating, with the underfloor heating being switched off again when the target temperature is reached and switching on again when the temperature drops to reach the desired target -Temperature value to be adjusted. Alternatively or additionally, he can also specify a heating start time or a heating duration from which or for how long the underfloor heating will be operated. This means that it has similar setting options as with a standard parking heater. For example, it is conceivable if the quick charging process itself is time-controlled and starts, for example, half an hour before a planned departure, and it is ensured that the battery is fully charged by the planned departure, that the driver then starts an underfloor heating time, for example a quarter of an hour before the planned departure, you can set the time at which the underfloor heating is switched on. In this case, it can be assumed that the battery is also sufficiently hot and that there is corresponding waste heat. In the event that, for whatever reason, there is not enough waste heat available from the battery charge, after defining a start of heating or a heating duration, these desired parameters can be used automatically to operate an additionally installed auxiliary heater, or for one operated from the charged battery Electric heating or the like. This means that the underfloor heating is automatically controlled and operated only when this is possible.

As described, a central element of the motor vehicle according to the invention is the underfloor heating, that is to say the heating circuit provided on the floor. This comprises one or more heating medium lines through which the heating medium of the underfloor heating system flows. Although it is possible to lay these heating medium line (s) as separate line coils, an expedient embodiment of the invention provides that the one or more heating medium lines are either integrated in a floor lining the passenger compartment or arranged on it, or that one or the other several heating medium lines are integrated in one or more heating mats arranged below the floor or arranged on it. Accordingly, the individual heating medium lines are consequently not laid separately, but are either an integral part of the floor lining the footwell or are fixedly arranged on the underside of the floor or carpet, which enables them to be laid in a particularly simple manner. Because they are then laid automatically when the floor or the carpeted floor is installed. It is then only necessary to connect the one or more heating medium lines to the inlet and outlet lines that lead to the heat exchanger device or to the pump. Alternatively, it is also conceivable to integrate the one or more heating medium lines in or to arrange them on corresponding heating mats, and then to install these heating mats as easy-to-install mat parts in the corresponding footwells, after which only the floor or carpet needs to be laid over them. In this case too, the heating medium lines of the underfloor heating system can be installed very easily.

• 1 eine Prinzipdarstellung eines erfindungsgemäßen Kraftfahrzeugs, und
• 2 eine Prinzipdarstellung einer Anordnung umfassend einen Batteriekühlkreislauf und einen Fußbodenheizkreislauf.

Further advantages and details of the present invention emerge from the exemplary embodiments described below and on the basis of the drawings. Show:

• 1 a schematic diagram of a motor vehicle according to the invention, and
• 2 a schematic diagram of an arrangement comprising a battery cooling circuit and a floor heating circuit.

1 shows a motor vehicle according to the invention 1 , comprising a passenger compartment 2 , the bottom side over a floor 3 , usually a suitably robust carpet or similar, is lined. The car 1 is a purely electric motor vehicle, so it has a corresponding electric drive with an or several electric motors, which are not shown here. This or these electric motors are made from a sufficiently large battery 4th fed which battery 4th in a recuperation operation is charged via the electric motor (s) then operated as generators, hence recuperated energy back into the battery 4th is pushed back. In addition, a charge can be charged via a suitable charging socket on the motor vehicle, into which a corresponding charging cable connected to a power source is plugged. The possibilities for charging such a battery 4th are well known.

The battery 4th is a battery cooling circuit 5 assigned, comprising one or more cooling lines in which a suitable coolant circulates, which is conveyed via a pump. This is about when the battery 4th heated during operation or during charging, the battery is cooled by the fact that the waste heat from the battery is absorbed and removed by the cooling fluid that circulates in the lines.

Underfloor heating is also planned 6th that are below the floor 3 arranged or is directly connected to this or integrated therein. This underfloor heating 6th serves to the passenger compartment 2 via a heating circuit 22nd to control the temperature on the bottom side, which leads to a very pleasant temperature control, as the heat rises from the bottom to the top. The underfloor heating 6th or the heating circuit 22nd comprises one or more coolant lines through which the heating-side heating medium circulates, which is also conveyed here via a corresponding pump.

The underfloor heating 6th or the heating circuit 22nd is via a heat exchanger device 7th with the battery cooling circuit 5 coupled. About this heat exchanger device 7th is via the battery cooling circuit 5 dissipated waste heat from the battery 4th to the heating circuit 22nd transfer. That is, the cooling fluid of the battery cooling circuit 5 via the heat exchanger device 7th Heat is withdrawn from the heating circuit 22nd the underfloor heating 6th where it is then transferred to the floor 3 respectively in the passenger cell 2 is delivered. As a result, the cooling fluid of the battery cooling circuit is cooled via the heat exchanger device 7th , associated with a heating of the heating fluid of the heating circuit 22nd the underfloor heating 6th .

2 shows a schematic diagram of the essential components of the battery cooling circuit 5 as well as the underfloor heating 6th . The battery cooling circuit 5 In the example shown, it comprises a coolant line which is guided here in a meandering manner 8th into which a pump 9 is connected, which promotes the cooling fluid. In the battery cooling circuit 5 is also a heat release structure 10 , here in the form of a cooling fin structure 11 , switched via which heat dissipation structure 10 then when the underfloor heating 6th is not switched on, the heat of the battery 4th is released into the environment, that is, the coolant in the battery cooling circuit 5 the heat is withdrawn and this is cooled again.

There is also a valve device 12th provided in the battery cooling circuit 5 is switched. About this valve device 12th the cooling fluid can either be in the partial circle 13th that is the heat release structure 10 includes, are conducted, or to the heat exchanger device 7th in the pitch circle 14th where the heat transfer to the underfloor heating fluid 6th he follows. That means that depending on whether the underfloor heating is now 6th should be operated or not, the cooling fluid of the battery cooling circuit 5 is guided accordingly. Will the underfloor heating 6th not driven, the cooling fluid is in the partial circle 13th and to the heat release structure 10 guided. Should the underfloor heating 6th are operated, the cooling fluid is via the valve device 12th in the second sub-cycle 14th routed to the heat exchanger.

To control the pump 9 as well as the valve device 12th is a control device 15th provided the corresponding control information via a data bus 16 from corresponding peripheral devices such as sensors, input elements, etc.

The control device 15th also serves the relevant components of the underfloor heating 6th to control or switch. The underfloor heating 6th also has a heating circuit 22nd forming heating medium line 17th on that here in two separate sub-cycles 18th , 19th is branched or relocated. One pump 20th promotes this in the heating medium line 17th located heating fluid to the heat exchanger 7th where it is from the cooling fluid of the battery cooling circuit 5 absorbs emitted heat. The heat exchanger 7th downstream is a valve device 21 , which is also via the control device 15th is switchable. About this valve device 21 the now heated heating fluid can either be transferred to the first partial circuit 18th or the second sub-cycle 19th or both sub-cycles 18th , 19th are supplied, that is, a corresponding cooling fluid distribution takes place via this. Depending on whether the temperature is controlled via one or the other or both sub-circuits 18th , 19th is desired, the valve device 21 controlled accordingly. For example, the first sub-circuit is in the footwell in front of the driver's seat and the second sub-circuit 19th arranged in the footwell in front of the passenger seat. Each person, i.e. the driver or front passenger, can switch on the underfloor heating individually respectively also set with regard to the desired temperature, which parameters in turn of the control device 15th via the data bus 16 are given. The control device 15th now switches the valve device 21 in such a way that the desired parameters can be set, so the quantities can be regulated accordingly, etc., of course via the data bus 16 corresponding actual temperature values can also be given if a corresponding setpoint temperature value is to be used, etc.

The two sub-cycles 18th , 19th run like 2 shows again in front of the pump 20th together, which circulates the heating fluid as described.

Even if only two sub-cycles are present 18th , 19th are shown, it is of course also conceivable to integrate a third or a fourth sub-circuit, which is then laid in the footwell (s) in front of the rear seats. The valve device 21 is then of course designed accordingly to also supply these additional sub-circuits separately.

If, for example, during fast charging, a person in the vehicle, for example the driver, receives an operating request for operating the underfloor heating via a corresponding input device 6th entered, the control device controls 15th the valve device 12th in such a way that from now on the cooling fluid no longer enters the partial circle 13th via the cooling fin structure 11 is performed, but only the heat exchanger device 7th is fed. The control device controls at the same time 15th the pump 20th on so that in the underfloor heating 6th the heating medium is circulated and it is via the heat exchanger device 7th can heat up. The valve device is also activated 21 , in such a way that this the heated heating means only the first partial circuit 18th , which is laid in front of the driver's seat, but not in the second partial circuit 19th , the one in front of the passenger seat that is not occupied or where no temperature control is desired. This means that in this case an individual temperature control only takes place in front of the driver's seat.

The activation of the underfloor heating 6th is of course only possible if on the part of the battery 4th there is sufficient heat to be dissipated, so that the battery cooling circuit 5 is in operation. The moment the driver expresses the floor heating request, is the battery 4th Not yet so hot that it has to be cooled, this is how the battery cooling circuit works 5 not yet. It is switched on automatically when a corresponding temperature threshold is exceeded by the actual battery temperature. Only then is the underfloor heating activated at the same time 6th switched on, because only then is the waste heat from the battery available, which is generated by the underfloor heating 6th for temperature control of the passenger cell 2 can be used.

The coolant line 17th respectively the individual sub-cycles 18th , 19th etc. are preferably integral elements of the floor 3 , that is, they are already prefabricated on the floor 3 educated. For example, the floor 3 have a lower plastic level or layer in which the corresponding cooling lines are already integrated or molded. This means that the corresponding pipes are immediately installed when the floor is installed 3 into the passenger compartment 2 It is only necessary to connect them to the corresponding inlet and outlet lines leading to the pump 20th respectively to the valve device 21 lead to join. Alternatively, it is also conceivable to integrate the corresponding lines or line sections on separate mats, which are then placed under the then thinner floor 3 be placed. In this case, too, a simple installation of the heating cable is possible.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was 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.

Patent literature cited

• US 2017/0106724 A1 [0005]

Claims (9)

Motor vehicle with electric drive, comprising at least one battery supplying one or more electric motors driving the vehicle with an associated battery cooling circuit (5), as well as a passenger cell (2) with a floor (3), characterized in that the battery cooling circuit (5) has a heat exchanger device ( 7) is coupled to a heating circuit (22) of an underfloor heating system (6). Motor vehicle after Claim 1 , characterized in that the battery circuit (5) and the heating circuit (22) each have a cooling fluid circulating therein and conveyed by a pump (9, 20). Motor vehicle after Claim 2 , characterized in that at least one switchable valve device (12) is provided in the battery cooling circuit (5), via which the cooling fluid can be fed either to the heat exchanger device (7) or to a heat release structure (10) integrated in the battery cooling circuit (5). Motor vehicle after Claim 3 , characterized in that the heat dissipation structure (10) comprises or is a cooling fin structure (11). Motor vehicle according to one of the preceding claims, characterized in that the heating circuit (22) has two or more separate partial circuits (18, 19) which are assigned to different areas within the passenger compartment (2) and to which, via at least one switchable valve device (21) controllable, the cooling fluid can be supplied separately. Motor vehicle according to one of the Claims 2 until 5 , characterized in that the battery cooling circuit (5) and the heating circuit (22) are each assigned a separate or a common control device (15) via which the operation of the respective pump (9, 20) and / or the or each valve device (12 , 21) is controllable. Motor vehicle after Claim 6 , characterized in that the or each control device (15) is set up to control the respective pump (9, 20) and / or the valve device (12, 21) as a function of the actual temperature of the battery (4). Motor vehicle after Claim 6 or 7th , characterized in that the or each control device (15) for controlling the respective pump (9, 20) and / or the valve device (12, 21) as a function of a user-definable, the target temperature in the passenger compartment (2) defining temperature value and / or a user-definable heating start time or heating duration of the underfloor heating system (6) is set up. Motor vehicle according to one of the preceding claims, characterized in that the heating circuit (22) has one or more coolant lines (17) which are either integrated into a floor (3) lining the passenger cell (2) or arranged on it, or which are in one or more several heating mats arranged below the floor (3) are integrated or arranged on it.

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