FR2973301A1 - ENERGY COGENERATION SYSTEM FOR ELECTRIC MOTOR VEHICLE - Google Patents

Abstract

1. An energy cogeneration system for an electric vehicle, comprising at least two vehicle member cooling-heating circuits (15, 17, 19), a device (3) for extending the range of the vehicle, a heating device Seebeck effect generator (7) implementing a hot source (9) and a cold source (11) to produce electrical energy, the hot source being constituted by a heat exchanger receiving a hot fluid, for example the hot combustion gases produced by the autonomy extension device (3) and the cold source being constituted by a heat exchanger receiving a cold fluid, characterized in that the fluid from the cold source feeds at least one cooling-heating circuit member (15, 17, 19), and in that the system comprises a tilting device adapted to switch the supply of fluid from the cold source of the at least one cooling-heating circuit su r at least one other, and a control device (25) of the tilt device adapted to be activated by the driver of the vehicle or autopilot.

Description

Energy cogeneration system for an electric motor vehicle. The invention relates to an energy cogeneration system for an electric motor vehicle. It is known that certain electric motor vehicles include an on-board electrical generation system, generally called a range extender, which is activated when necessary with regard to the state of charge of the vehicle's driving battery. The range extender may be for example a heat engine associated with an electric generator or a fuel cell fueled by a gas mixture, said reformate, rich in hydrogen, produced on board the vehicle from a liquid fuel, such as than ethanol. Seebeck thermo-generators are also known which make it possible to recover a part of the thermal energy of the exhaust gas of the range extender, for example the thermal energy of the exhaust gases constitutes approximately one-third of the energy contained in the fuel in the case of a range extender with thermal engine and current generator. These thermo generators produce electricity from a hot thermal source, which is for example the exhaust of the range extender heat engine, and a cold thermal sink (lower temperature than that of the hot source) and which can be a coolant of a vehicle body. Nevertheless, the known Seebeck effect thermo-generators use only one cold source, which, because of the transfer of heat from the hot source to the cold source, can be brought to heat and consequently the production of electrical energy of these thermo generators decreases. There is a need to improve the electrical power generation of these Seebeck effect thermo generators on electric motor vehicles. Furthermore, the current devices do not allow to value the heat transferred to the cold source (cold thermal sink) of the Seebeck effect thermo generator.

There is therefore also a need to value the heat transferred to the cold source. According to the invention, there is provided an energy cogeneration system for an electric vehicle, comprising - at least two vehicle member cooling-heating circuits, - a vehicle autonomy extension device, - a thermo generator device for the vehicle, Seebeck effect using a hot source and a cold source to produce electrical energy, the hot source being constituted by a heat exchanger receiving a hot fluid, for example the hot combustion gases produced by the extension device of autonomy and the cold source being constituted by a heat exchanger receiving a cold fluid, characterized in that the fluid from the cold source feeds at least one of said organ cooling-heating circuits (upstream of said member), and in that that the system comprises a tilting device adapted to switch the supply of fluid from the cold source of the at least one cooling circuit oidissement-heating on at least one other, and a control device of the tilt device adapted to be activated by the driver of the vehicle or by an automatic vehicle control device. The term "cooling-heating circuit" of a member of the vehicle means a circuit containing a fluid cooling or heating the member either by direct contact between said circuit and said member, or indirectly via a heat exchanger between said circuit and said member. It may be a cooling-heating circuit of the vehicle cabin, a cooling-heating circuit of the vehicle traction battery, a cooling-heating circuit of the electrotechnical components or a cooling-heating circuit of the heat engine of the autonomy extension device. Within the meaning of the invention, the member may therefore be a functional element of the vehicle (battery, engine, ...) or an area thereof (cockpit).

In the present description, the terms upstream and downstream are to be understood with respect to the direction of circulation of the fluid in the circuits. Such a system makes it possible to optimize the recovery of the thermal energy of a hot fluid consisting, for example, of the hot combustion gases produced by the autonomy extension device, this recovery being carried out in the form of electrical energy to recharge the battery. a traction battery or supplying electrical accessory parts of the vehicle, or supplying the traction motor of the vehicle, or being produced in the form of thermal energy by the supply of heat from the hot source to the cold source for heating the cooling circuit -heating of the selected vehicle member, for example the cooling-heating circuit of the passenger compartment, the cooling-heating circuit of the traction battery for the latter to operate in its optimum temperature zone, the cooling circuit the engine for example at the beginning of its operation so that the latter reaches its temperature more quickly erasure optimum operating or other vehicle fluid.

Each organ cooling-heating circuit of said vehicle is advantageously connected, downstream of the member, to the cold source so as to supply this cold source with fluid flowing in said circuit. The cooling-heating circuits are then closed, and the system may include a plurality of organ heating-cooling circuits connected in parallel with the cold source, each circuit being provided with a three-way solenoid valve opening or closing the feeding said circuit. In general, in the case of closed cooling-heating circuits, the system according to the invention may comprise a tilting device upstream and / or downstream of said circuits. Alternatively, the fluid may be a gaseous coolant. In particular, the cold source can then be directly powered by the outside air. The cooling-heating circuits are then open and the system may comprise a plurality of cooling-heating circuits for a gaseous heat-transfer fluid, and at least one valve element for distributing the heat transfer fluid leaving the cold source on at least one of one of the circuits, even in the external environment. Of course, closed circuits may also be considered for a gaseous coolant when the latter can not be released into the air. The control device may be able to control the tilting device in order to switch the supply of fluid leaving the cold source of at least one cooling-heating circuit to at least one other according to a setpoint chosen from a maximum temperature setpoint of said circuit, a setpoint of optimum efficiency of the system or of the optimum difference between the cold source and the hot source, a set temperature in the passenger compartment. The tilting device may comprise at least one valve element or solenoid valve for distributing the fluid coming from the cold source to supply the at least one cooling-heating circuit, for example three-way solenoid valves (opening or closing each circuit) mounted. on the supply ducts of the circuits connected in parallel on the cold source.

The range extender device may be of the type with a heat engine and an electric current generator, or with a fuel cell producing electric power. The cooling-heating circuits may comprise a heat transfer fluid which may be in liquid form, water for example, or in gaseous form, such as air. In the case where the heat transfer fluid is a liquid, the heat exchanger of the Seebeck effect thermo-generator device is of the liquid gas type, and in the case where the coolant is a gas, the heat exchanger is of the gas gas type.

The control device can be autopilot or manual control. The automatic control can be carried out according to an optimal energy efficiency guideline of the Seebeck effect thermo generator, preserving an optimal temperature difference between the hot source and the cold source, or according to a comfort guideline in the vehicle, preserving the temperature in the passenger compartment of the vehicle, or according to an optimal operating instruction of the drive members of the vehicle, for example preserving the temperature of the traction battery, or the heat engine (at the beginning of operation) of the range extender device etc ....

It is furthermore proposed a method of implementing a system as described above, in which the cold source is fed with a fluid, and in which this fluid is heated by passing through the cold source, is returned to at least one a vehicle body cooling-heating circuit, upstream of the member.

The fluid supplying the cold source may be a gaseous coolant, such as the outside air of the vehicle, or a liquid heat transfer fluid, such as water, circulating in one of the cooling-heating circuits of a body of the vehicle, taken downstream of this organ.

The fluid exiting the cold source is directed by the tilting device to at least one cooling-heating circuit as a function of a setpoint chosen from a maximum temperature setpoint of said circuit, an optimal performance setpoint of the system or the optimal distance between the cold source and the hot source, a set temperature in the passenger compartment. It is also proposed an electric vehicle comprising a system of energy cogeneration as described above. The system according to the invention can make it possible to ensure alone the thermal management of several organs of the vehicle.

However, it can be envisaged that the system according to the invention is coupled to conventional cooling-heating circuits of the components of an electric vehicle. It can be envisaged that each member (or some of the members) is further cooled-heated by another cooling-heating circuit, for example connected in parallel to the corresponding circuit of the system according to the invention. Embodiments of the invention are now described by way of nonlimiting example and with reference to the appended drawing in which: FIG. 1 is a schematic view of an energy vehicle cogeneration system for an electric vehicle according to one embodiment of the invention, and FIG. 2 is a view similar to FIG. 1 of an alternative embodiment.

With reference to the drawing, the energy cogeneration system 1 for an electric vehicle shown comprises an extension device 3 of the vehicle which is seen only a conduit 5 for output of the combustion gases, for example the thermal drive motor. electric generator. This autonomy extension device 3 is connected to a Seebeck effect thermo generator device 7 comprising a first heat exchanger 9 receiving the combustion gases of the aforementioned gas outlet pipe 5 as a hot source of the thermo-generator device.

A second heat exchanger 11 as a cold source of the Seebeck effect thermo-generator device receives a coolant, for example water 13 or air flowing in arrows to various cooling-heating circuits of the vehicle, for example the circuit 15 for cooling-heating the traction battery (maximum T at approximately 50 ° C), the cooling-heating circuit 17 of the passenger compartment of the vehicle, the cooling circuit 19 of the heat engine of the range extender device ( T maximum at about 100-110 ° C) or alternatively (not shown) a cooling circuit of the electrotechnical components of the vehicle (electric traction motor, generatrix of the range extender, power electronics components (maximum T about 60 at 70 ° C.) When it is indicated that the fluid circulates in a cooling-heating circuit of a vehicle member, it may be a branch of the circuit of the organ and for example at least one heat exchanger circuit portion of a cooling-heating circuit of a vehicle member. The thermocouple device Seebeck effect 7 is further connected by electric cables 21 to a set 23 of traction battery and various electrical accessories of the vehicle that can supply electrical energy selectively with an electric power of 10 to 40 kW in the case of an electric vehicle, under the command of a control device 25 of the system operated by the driver (driver) of the vehicle or by an automatic control device (computer).

The cooling-heating circuits 15, 17, 19 are connected in parallel to the circuit 26, 27 of the cold source, each being fed selectively by a three-way solenoid valve 29 mounted at the inlet of each circuit. Each of the solenoid valves 29 opens on one circuit and closes on the other or vice versa, under the control of the control device. Optionally, the solenoid valve upstream of the circuit can operate in synchronism with a valve element downstream of the circuit (not shown). This valve element can prevent any introduction of fluid downstream of the circuit when the solenoid valve of the circuit is closed. In fig. 1, circuit 15 alone is open. These circuits each comprise a sensor of the temperature of the fluid in the circuit, connected to the control device 25 of the system. The device 25 controls the opening or closing of each of the 3-way solenoid valves 29 of the circuits and also manages the supplementary power supply by the thermogenerator device of the traction battery or the electrical accessories 23 of the vehicle according to a law of control of the system, which can be manually selected by the driver of the vehicle or automatically by the vehicle control device. The operation of the system is now described. Thus, according to a control of the device favoring energy efficiency, in a cold environment, it is possible to accelerate the rise in temperature of the traction battery by opening the corresponding circuit valve 15, which will allow the circulation of the fluid of the cold source in this case. circuit 15 and cause this fluid to be heated by the cold source. This heating will increase the power and available energy of the battery and therefore increase the speed and acceleration performance of the vehicle in a cold environment. At the same time, the electrical energy supplied by the thermo generator device 7 can supply the traction motor and other electrical accessories of the vehicle, thus reducing the electrical consumption of the vehicle by the traction battery alone. It is still possible to control the control device 25 in a cabin comfort setting, by giving priority to feeding the heating circuit 17 of the passenger compartment, in particular in a cold environment, which reduces the consumption of the electric heating resistors of the passenger compartment. the cockpit on the traction battery. In addition, the possibility of switching from one cold source to another or several others makes it possible to increase the temperature difference between the hot source 9 and the cold source 11 (and therefore with a better yield of the Seebeck thermo-generator) and leaves a lot of freedom for the steering strategies. Thus, if priority is given to the thermal comfort of the passenger compartment and to the temperature rise of the generator engine, then it is the coolant of the engine that will first be connected first as a cold source, then the cockpit circuit. If the priority is given to the temperature rise of the traction battery to increase the performance of the vehicle in a cold environment then it is the coolant of the battery which will be connected in priority as a cold source then, when the priority has disappeared, several heating cooling circuits can be powered simultaneously by the solenoid valves 29 according to the setpoints of the control drive.

It should be noted that some of the members may further be cooled or heated by another heating cooling circuit, for example connected in parallel to the corresponding circuit of the system. Thus, it is possible to connect a heating circuit 37 (via an electric heater) to the heat engine circuit 19 and a similar heating circuit 39 to the battery circuit 15, or even to the heating circuit for heating the electrotechnical components of the vehicle ( electric traction motor, generator of range extender, power electronics components). Thermostats 41 and 43 respectively disposed on these circuits 37, 39 open or close these circuits according to the system control instructions. Naturally, according to the system 1 'of FIG. 2 in the case of the variant embodiment with a Seebeck effect thermo-generator device system 7 'with a gas-air exchanger, the hot source 9' consists of the exhaust gases of the range extender and the cold source 11 'is air. The air is drawn outside at 31 and can be conveyed by a fan 34 and by the valve 29 ', under the control of the control device 25' and in servocontrol at a sensor temperature setpoint 30 'to the control circuit. heating the passenger compartment 33 after being heated in the exchanger 11 '.

The air drawn outside 31 can still be conveyed by the fan 34 and the valve 29 'to the heating of the battery 35 after being heated in the exchanger 11' (if the battery is cooled by air). The air drawn outside 31 can also be discharged 31 'outside by the valve 34 after passing through the exchanger 11'. In this case, there is no heat recovery. The advantages of the system remain the same as in the embodiment of FIG. 1 with regard to the generation of electric current and heat recovery, in particular for heating the battery in a cold environment and heating the passenger compartment in a cold environment.

Claims (10)

REVENDICATIONS1. Electric vehicle energy cogeneration system (1,1 '), comprising - at least two vehicle member cooling-heating circuits (15, 17, 19, 33, 35), - an extension device (3) of vehicle autonomy, - a Seebeck effect thermo-generator device (7, 7 ') implementing a hot source (9, 9') and a cold source (11, 11 ') in order to produce energy electric, the hot source (9, 9 ') being constituted by a heat exchanger receiving a hot fluid, for example the hot combustion gases produced by the autonomy extension device (3) and the cold source (11, 11'). being constituted by a heat exchanger receiving a cold fluid, characterized in that the fluid from the cold source feeds at least one of said organ cooling-heating circuits (15, 17, 19; 33, 35), and in that that the system comprises a tilting device adapted to switch the fluid supply from the sour this cold of the at least one cooling-heating circuit (15, 17, 19; 33, 35) on at least one other, and a control device (25, 25 ') of the tilt device adapted to be activated by the driver of the vehicle or by an automatic vehicle control device. 2. System (1) according to claim 1, characterized in that each cooling-heating circuit (15, 17, 19) of the body of said vehicle is connected, downstream of the body, to the cold source (11) . 3. System (1, 1 ') according to claim 1 or 2, characterized in that the organ cooling-heating circuits (15, 17, 19; 33, 35) are selected from the cooling-heating circuits of the battery, electrotechnical components, the habitable and / or the engine. 4. System (1, 1 ') according to one of claims 1 to 3, characterized in that the control device (25, 25') is adapted to control the tilting device (29, 29 ') in order to switch at least one cooling-heating circuit (15, 17, 19, 33, 35) on at least one other according to a setpoint chosen from a maximum temperature setpoint of said circuit, an optimal performance reference of the system or of the optimum distance between the cold source (11, 11 ') and the hot source (9, 9'), a temperature setpoint in the passenger compartment. 5. System according to any one of the preceding claims, characterized in that the tilting device (29, 29 ') comprises at least one valve member or solenoid valve (29, 29') for distributing the fluid from the cold source to supplying the at least one cooling-heating circuit (15, 17, 19; 33, 35). 6. A method of implementing a system according to one of the preceding claims, wherein the cold source (11, 11 ') is fed with a fluid, and wherein the fluid heated by passing through the cold source, is returned to at least one cooling-heating circuit (15, 17, 19, 33, 35) of the vehicle body, upstream of the member. 7. The method of claim 6, wherein the fluid supplying the cold source (11 ') is the outside air of the vehicle. 8. The method of claim 6, wherein the fluid supplying the cold source (11) is a coolant circulating in at least one cooling-reheating circuit (15, 17, 19) of the vehicle body, taken downstream of the or organ (s). 9. The method of claim 6, 7 or 8, wherein the fluid exiting the cold source (11, 11 ') is directed by the tilting device to at least one cooling-heating circuit (15, 17, 19; 33, 35) as a function of a set point selected from a maximum temperature setpoint of said circuit, a setpoint of optimal system efficiency or of the optimum difference between the cold source (11, 11 ') and the hot source (9, 9 '), a set temperature in the passenger compartment. Electric vehicle comprising an energy cogeneration system according to any one of claims 1 to 5.