WO2020035642A1 - Thermoelectric machine in particular for hybrid electric vehicles with extended driving range - Google Patents
Thermoelectric machine in particular for hybrid electric vehicles with extended driving range Download PDFInfo
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- WO2020035642A1 WO2020035642A1 PCT/FR2019/051722 FR2019051722W WO2020035642A1 WO 2020035642 A1 WO2020035642 A1 WO 2020035642A1 FR 2019051722 W FR2019051722 W FR 2019051722W WO 2020035642 A1 WO2020035642 A1 WO 2020035642A1
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02G—HOT GAS OR COMBUSTION-PRODUCT POSITIVE-DISPLACEMENT ENGINE PLANTS; USE OF WASTE HEAT OF COMBUSTION ENGINES; NOT OTHERWISE PROVIDED FOR
- F02G5/00—Profiting from waste heat of combustion engines, not otherwise provided for
- F02G5/02—Profiting from waste heat of exhaust gases
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
- F02F5/00—Piston rings, e.g. associated with piston crown
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
- H10N10/10—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects operating with only the Peltier or Seebeck effects
- H10N10/13—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects operating with only the Peltier or Seebeck effects characterised by the heat-exchanging means at the junction
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E20/00—Combustion technologies with mitigation potential
- Y02E20/14—Combined heat and power generation [CHP]
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Definitions
- the invention relates generally to the generation of electricity from heat by the application of the thermoelectric effect known as the Seebeck effect. More particularly, the invention relates to a thermoelectric machine for primary energy conversion, in particular for applications in vehicles and, in particular, hybrid electric vehicles with extended range. The invention also relates to a vehicle comprising a thermoelectric machine notably in its traction chain.
- thermoelectric generation based on the Seebeck effect takes advantage of the potential difference appearing between two conductive materials of different natures, subjected to a temperature gradient, to produce electricity from heat.
- a reverse thermoelectric conversion is obtained with the Peltier effect which produces a temperature gradient in two conductive materials of different natures between which a potential difference is applied.
- thermoelectric generators In vehicles, it is known to use thermoelectric generators as a secondary energy converter to produce electricity by recovering part of the waste heat from internal combustion engines. Thus, a thermoelectric generator has been proposed converting the heat contained in the exhaust gases of the internal combustion engine into electricity. By W02008095582A1, it is known to recover heat directly from the engine block of the internal combustion engine and convert it into electricity using a thermoelectric generator.
- the thermoelectric generator offers the advantage of a conversion of static energy, without any mechanical wear due to moving parts as in an electric alternator.
- the efficiency of known thermoelectric generators remains low and depends in particular on the merit factor ZT of the conductive materials used. P and N type semiconductor materials are used in current thermoelectric generators. Promising research is underway to develop nanostructured materials with a high ZT merit factor.
- Fig.1 schematically shows a known architecture of an MTE thermoelectric machine with external combustion which is designed for primary energy conversion.
- the MTE thermoelectric machine supplies electrical energy from the heat produced by the external combustion of a fuel.
- the thermoelectric machine MTE includes a GTE thermoelectric generator and a CO combustion device.
- the GTE generator here comprises a single thermoelectric module TE.
- the thermoelectric module TE comprises a first thermoelectric material M n , typically an N type semiconductor, and a second thermoelectric material MP, typically a P type semiconductor.
- First ends of the thermoelectric materials MN, M p are interconnected and thermally connected to a TE hot head h .
- Second ends of the thermoelectric materials M N , M P are thermally connected to a cold head TE C and connected respectively to positive electrical terminals B + and negative B-.
- the TE H and TE C hot and cold heads are here heated and cooled by hot and cold heat transfer liquids from EX H hot and EX C cold heat exchangers which form cold and hot sources, respectively. It is the temperature gradient GT imposed by the hot TE H and cold TE C heads in the thermoelectric materials M N , M P , which produces by Siebeck effect a potential difference V between the electrical terminals B + and B-.
- the CO combustion device comprises an air blower BL, a combustion chamber CH and the hot heat exchanger EX H.
- the BL air blower is responsible for drawing the incoming air AIR towards the combustion chamber CH.
- a fuel is injected into the CH combustion chamber to be burned there and produce heat.
- Combustion gases EG leaving the combustion chamber CH pass through the hot heat exchanger EX H and release calories there before being evacuated outside.
- thermoelectric machines with external combustion such as the MTE machine described above
- a thermodynamic cycle efficiency that is to say, a net work generated compared to the amount of heat. provided to the cycle, which depends on the merit factor ZT.
- the overall efficiency of the machine that is to say, the net work generated compared to the energy consumed in the combustion chamber, it is low because a large part of the energy provided by the combustion of the fuel goes outside with the combustion gases and the fact that the merit factor ZT has a value which is often limited.
- a thermal regenerator or heat recovery to recover calories in the combustion gases before the evacuation thereof to the outside. The calories recovered by the regenerator are transferred to the air inlet of the combustion chamber in order to increase the temperature of the incoming air and thus reduce the amount of fuel injected into the combustion chamber.
- thermoelectric machines of the prior art provide an improvement in the overall efficiency of the thermoelectric machine, but it remains insufficient, in particular for applications in the traction of a motor vehicle.
- power density that the thermoelectric machines of the prior art can offer remains low.
- thermoelectric machine having an improved architecture capable of offering better energy efficiency.
- the invention relates to a thermoelectric machine comprising a thermoelectric generator comprising first and second thermoelectric modules arranged in series inside the thermoelectric generator, first and second hot exchangers connected in series in a circuit circulation of combustion gases and connected respectively to the first and second thermoelectric modules so as to heat them, first and second cold exchangers connected respectively to the first and second thermoelectric modules so as to cool them, and a first combustion chamber supplied with air and fuel and ensuring a first combustion producing combustion gases circulating in the combustion gas circulation circuit.
- the thermoelectric machine also includes a second combustion chamber inserted between the first and second hot exchangers in the combustion gas circulation circuit, the second combustion chamber being supplied with fuel and providing post combustion for reheating. combustion gases.
- the combustion in the first combustion chamber is adjusted to be non-stoichiometric and to produce an excess of air in the combustion gases.
- Non-stoichiometric combustion limits the maximum temperature to a value compatible with the metallurgical limits of the materials of the combustion chamber.
- thermoelectric generator comprises a third thermoelectric module arranged in series with the second thermoelectric module inside the thermoelectric generator, and the thermoelectric machine comprises a third hot exchanger connected in the gas circulation circuit combustion, downstream of the second hot exchanger, and connected to the third thermoelectric module, a third cold exchanger connected to the third thermoelectric module, and a third combustion chamber inserted between the second and third hot exchangers in the circuit for circulation of combustion gas , the third combustion chamber being supplied with fuel and providing post combustion for heating the combustion gases.
- the combustion in the second combustion chamber is adjusted to be non-stoichiometric and to produce an excess of air in the combustion gases.
- thermoelectric machine also comprises a thermal regenerator ensuring preheating of the incoming air with calories recovered in the combustion gases before the evacuation of these to the outside.
- thermoelectric machine also includes an air blower producing pulsed incoming air.
- the invention also relates to a range extender for an electric or hybrid electric vehicle comprising a thermoelectric machine as briefly described above.
- the invention relates to a vehicle comprising a thermoelectric machine as briefly described above.
- Fig.1 is a block diagram of a thermoelectric machine of the prior art
- thermoelectric machine according to the invention, comprising two thermoelectric modules
- thermoelectric machine is a block diagram of a second embodiment of the thermoelectric machine according to the invention, comprising three thermoelectric modules;
- thermoelectric machines according to the present invention is a comparative graph showing Pareto performance diagrams, for thermoelectric machines according to the present invention and thermoelectric machines of the prior art.
- the MTE1 thermoelectric machine is here a primary energy converter which supplies electrical energy and heat from the external combustion of a fuel.
- the thermoelectric machine MTE1 includes in particular a thermoelectric generator GTE1, a combustion-regeneration device CR, first and second exchangers EX1 H , EX2 H , called “hot” and first and second exchangers EX1 C , EX2 C , called “cold”.
- the thermoelectric generator GTE1 and the exchangers EX1 C , EX2 C supply electrical energy and heat, in cogeneration.
- the generator GTE1 here comprises two thermoelectric modules TE1 and TE2.
- the first and second thermoelectric modules TE1 and TE2 are connected respectively to the first heat exchangers EX1 H and cold EX1 C and to the second heat exchangers EX2 H and cold EX2 C.
- Each thermoelectric module TE1, TE2 comprises the thermoelectric materials M N , M P , with hot TE H and cold TE C heads at their ends.
- the combustion-regeneration device CR here essentially comprises an air blower BL, a thermal regenerator REG, a combustion assembly EH and the first and second hot exchangers EX1 H and EX2 H.
- REG thermal regenerator is a heat recuperator which contributes to improving the overall performance of the machine by allowing preheating of the incoming air AIR.
- Regenerator REG recovers calories from combustion gases EG2 before their evacuation to the outside in the form of exhaust gases EG3. The calories recovered are used to heat the incoming air AIR which is pulsed by the BL air blower.
- the present invention uses several combustion chambers for the production of heat.
- the combustion unit EH comprises two combustion chambers, namely, a first chamber CH1 and a second chamber CH2.
- the first combustion chamber CH1 is located directly downstream of the REG regenerator.
- the first combustion chamber CH1 receives as input the pulsed air AIR which has been heated by the regenerator REG.
- Fuel is injected into the first combustion chamber CH1 and the combustion of this produces first combustion gases EG1.
- the first hot exchanger EX1 H disposed directly downstream of the first combustion chamber CH1, is crossed by the gases EG1 which release calories there.
- the second combustion chamber CH2 is located directly downstream of the first hot exchanger EX1 H and provides post combustion.
- the second combustion chamber CH2 receives as input the first combustion gases EG1 which have been cooled by passing through the first hot exchanger EX1 H. Fuel is injected into the second combustion chamber CH2 and the combustion of this produces post-combustion gases EG2.
- the second hot exchanger EX2 H disposed directly downstream of the second combustion chamber CH2, is traversed by the gases EG2 which transfer calories there.
- the gases EG2, cooled by passing through the second hot exchanger EX2 H then pass through the regenerator REG before being discharged to the outside in the form of the exhaust gases EG3.
- the second combustion chamber CH2 allows for intermediate heating of the combustion gases between the first and second hot exchangers EX1 H and EX2 H.
- This heating of the combustion gases makes it possible to reduce the temperature difference between the first and second modules.
- the heating of the combustion gases is determined so that the two thermoelectric modules TE1 and TE2 operate at the same temperature level. The TE1 and TE2 thermoelectric modules then operate identically and the complexity of the machine is reduced.
- the combustion in the first combustion chamber CH1 is adjusted so as to have an excess of air in the outgoing combustion gases EG1 (non stoichiometric combustion), which reduces the combustion temperature in a room and makes it possible to comply with the metallurgical limit of temperature resistance of the materials thereof.
- the excess air present in the combustion gases EG1 allows the post combustion to reheat in the second combustion chamber CH2.
- Non-stoichiometric combustion in the first CH1 combustion chamber offers the advantage of a lower combustion temperature compared to non-stoichiometric combustion, which reduces the stresses on the materials of the CH1 chamber.
- the combustion in the first combustion chamber CH1 will be stoichiometric and the skilled person will provide an air supply in the second combustion chamber CH2 to obtain satisfactory combustion therein, and a production of sufficient heat for reheating.
- preheating of the incoming air AIR provided by the REG regenerator upstream of the first combustion chamber CH1 is not essential for the implementation of the invention. However, in addition to its positive effect on improving the overall efficiency of the machine, preheating by the REG regenerator leads to a lesser amount of fuel injected into the chamber, which promotes an increased amount of oxygen in the combustion gases EG1 for reheating after combustion.
- thermoelectric generator according to the invention allows a reduction of nitrogen oxides (NOx) at the source.
- NOx nitrogen oxides
- the lowering of the temperature in the first chamber CH1 by a non-stoichiometric combustion and the post combustion combustion provided in the second chamber CH2 limit the production of NOx with fuels such as petrol, diesel or fuel oil.
- the low temperature in the first chamber CH1 favors a lower production of NOx and the post combustion ensured in the second chamber CH2 burns these, in a similar manner to what occurs in a heat engine equipped with an EGR valve for recirculating the exhaust gas.
- the invention is not limited to a thermoelectric machine having two thermoelectric modules and is also applicable in machines having three and more thermoelectric modules.
- the thermoelectric machine according to the invention may thus comprise two or more combustion chambers for intermediate reheating of the combustion gases which supply heat to the thermoelectric modules.
- FIG. 3 An example of architecture of a MTE2 thermoelectric machine according to the invention with three thermoelectric modules is shown in Fig.3.
- the machine MTE2 comprises a generator GTE2 having an additional thermoelectric module TE3 with which is associated an additional combustion chamber CH3 and heat exchangers EX3H and cold EX3c .
- the combustion chamber CH3 heats the combustion gases between the hot exchangers EX2 H and EX3H, in a similar manner to the combustion chamber CH2 between the hot exchangers EX1 H and EX2 H , as already described with reference to Fig. 2 .
- the post combustion in the second chamber CH2 is made with excess air so as to conserve oxygen for the post combustion in the third chamber CH3.
- the present invention offers an increase of the order of ten to fifteen percentage points on the overall efficiency of the thermoelectric generator and a power density multiplied by a factor of between two and three.
- thermoelectric machines of the prior art A comparison of performance, between thermoelectric machines of the prior art and thermoelectric machines according to the present invention, is provided by the graph in Fig.4 which represents, for a combustion temperature of 1250 ° C, diagrams of Pareto of the specific net work or power density (denoted TNS) in kilojoule / kilogram compared to the energy efficiency (denoted RM) of the machine.
- TNS specific net work or power density
- RM energy efficiency
- the machines TE (n1) i to TE (n3) i, TE (n1) 4 to TE (n3) are machines without regenerator having respectively 1 to 3 thermoelectric modules.
- Machines TE (R / n1) i to TE (R / n3) i, TE (R / n1) 4 to TE (R / n3) 4 are machines with regenerator having respectively 1 to 3 thermoelectric modules.
- the TE-Re thermoelectric machines all include heating combustion chambers (Re) between the thermoelectric modules, as described above with reference to Figs. 2 and 3.
- the TE- Re (n2) i and TE-Re machines ( n3) i, TE-Re (n2) 4 and TE-Re (n3), are machines without regenerator having respectively 2 and 3 thermoelectric modules.
- the machines TE-Re (R / n2) i and TE-Re (R / n3) i, TE-Re (R / n2) 4 and TE-Re (R / n3), are machines with regenerator having respectively 2 and 3 thermoelectric modules, like those shown in Figs. 2 and 3.
- the graph in Fig.4 clearly shows the significant increases in efficiency and power density provided by the TE-Re thermoelectric machines according to the invention compared to the TA thermoelectric machines of the prior art.
- thermoelectric machines according to the invention can be envisaged for applications in the traction chains of transport vehicles, in particular in hybrid electric vehicles of the series hybrid, parallel hybrid and series - parallel hybrid type, in particular in a context of zero. emission of C0 2 and hardening of environmental standards. It will be noted that the thermoelectric machines according to the invention are also applicable as a range extender for electric and electric hybrid vehicles.
- thermoelectric machines being of the external combustion type, they are compatible with all types of fuel which include petrol, diesel, fuel oil and the like, but also hydrogen, methane, solid fuels such as wood, aluminum, iron, magnesium and others.
- thermoelectric machines according to the invention will also find applications in energy cogeneration systems, in particular in hybrid vehicles, heavy goods vehicles, the space sector and others.
- the invention is not limited to the particular embodiments which have been described here by way of example. Those skilled in the art, depending on the applications of the invention, can make different modifications and variants falling within the protective field of the invention.
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Abstract
The thermoelectric machine (MTE1) includes a thermoelectric generator (GTE1) comprising first and second thermoelectric modules (TE1, TE2) arranged in a series inside the generator, first and second hot exchangers (EX1H, EX2H) connected in a series and connected to the thermoelectric modules so as to heat same, first and second cold exchangers (EX1C, EX2C) connected to the thermoelectric modules so as to cool same, and a first combustion chamber (CH1) providing a first combustion and producing combustion gases (EG1) circulating in a combustion gas circulation circuit. According to the invention, the machine also includes a second combustion chamber (CH2) inserted between the hot exchangers in the combustion gas circulation circuit, the second combustion chamber providing a reheating post combustion of combustion gases (EG1, EG2).
Description
MACHINE THERMOÉLECTRIQUE NOTAMMENT POUR DES VÉHICULES ÉLECTRIQUES HYBRIDES À AUTONOMIE ÉTENDUE THERMOELECTRIC MACHINE IN PARTICULAR FOR EXTENDED HYBRID ELECTRIC VEHICLES
[001 ] L’invention concerne de manière générale la génération d’électricité à partir de la chaleur par l’application de l’effet thermoélectrique dit effet Seebeck. Plus particulièrement, l’invention se rapporte à une machine thermoélectrique de conversion primaire d’énergie notamment pour des applications dans des véhicules et, en particulier, les véhicules électriques hybrides à autonomie étendue. L’invention concerne aussi un véhicule comprenant une machine thermoélectrique notamment dans sa chaîne de traction. The invention relates generally to the generation of electricity from heat by the application of the thermoelectric effect known as the Seebeck effect. More particularly, the invention relates to a thermoelectric machine for primary energy conversion, in particular for applications in vehicles and, in particular, hybrid electric vehicles with extended range. The invention also relates to a vehicle comprising a thermoelectric machine notably in its traction chain.
[002] La génération thermoélectrique basée sur l’effet Seebeck met à profit la différence de potentiel apparaissant entre deux matériaux conducteurs de natures différentes, soumis à un gradient de température, pour produire de l’électricité à partir de la chaleur. Une conversion thermoélectrique inverse est obtenue avec l’effet Peltier qui produit un gradient de température dans deux matériaux conducteurs de natures différentes entre lesquels est appliquée une différence de potentiel. The thermoelectric generation based on the Seebeck effect takes advantage of the potential difference appearing between two conductive materials of different natures, subjected to a temperature gradient, to produce electricity from heat. A reverse thermoelectric conversion is obtained with the Peltier effect which produces a temperature gradient in two conductive materials of different natures between which a potential difference is applied.
[003] Dans les véhicules, il est connu d’utiliser des générateurs thermoélectriques en tant que convertisseur secondaire d’énergie pour produire de l’électricité par récupération d’une partie de la chaleur perdue des moteurs à combustion interne. Ainsi, il a été proposé un générateur thermoélectrique convertissant en électricité la chaleur contenue dans les gaz d’échappement du moteur à combustion interne. Par W02008095582A1 , il est connu de récupérer la chaleur directement sur le bloc-moteur du moteur à combustion interne et de la convertir en électricité à l’aide d’un générateur thermoélectrique. De manière générale, le générateur thermoélectrique offre l’avantage d’une conversion d’énergie statique, sans aucune usure mécanique due à des organes en mouvement comme dans un alternateur électrique. Par contre, le rendement des générateurs thermoélectriques connus reste faible et dépend notamment du facteur de mérite ZT des matériaux conducteurs utilisés. Des matériaux semiconducteurs de type P et N sont utilisés dans les générateurs thermoélectriques actuels. Des recherches prometteuses sont en cours afin de mettre au point des matériaux nanostructurés ayant un haut facteur de mérite ZT. In vehicles, it is known to use thermoelectric generators as a secondary energy converter to produce electricity by recovering part of the waste heat from internal combustion engines. Thus, a thermoelectric generator has been proposed converting the heat contained in the exhaust gases of the internal combustion engine into electricity. By W02008095582A1, it is known to recover heat directly from the engine block of the internal combustion engine and convert it into electricity using a thermoelectric generator. In general, the thermoelectric generator offers the advantage of a conversion of static energy, without any mechanical wear due to moving parts as in an electric alternator. On the other hand, the efficiency of known thermoelectric generators remains low and depends in particular on the merit factor ZT of the conductive materials used. P and N type semiconductor materials are used in current thermoelectric generators. Promising research is underway to develop nanostructured materials with a high ZT merit factor.
[004] La Fig.1 montre de manière schématique une architecture connue d’une machine thermoélectrique MTE à combustion externe qui est conçue pour une conversion primaire d’énergie. La machine thermoélectrique MTE fournit de l’énergie électrique à partir de la chaleur produite par la combustion externe d’un carburant. La machine thermoélectrique
MTE comprend un générateur thermoélectrique GTE et un dispositif de combustion CO. Le générateur GTE comporte ici un seul module thermoélectrique TE. Fig.1 schematically shows a known architecture of an MTE thermoelectric machine with external combustion which is designed for primary energy conversion. The MTE thermoelectric machine supplies electrical energy from the heat produced by the external combustion of a fuel. The thermoelectric machine MTE includes a GTE thermoelectric generator and a CO combustion device. The GTE generator here comprises a single thermoelectric module TE.
[005] Le module thermoélectrique TE comprend un premier matériau thermoélectrique Mn, typiquement un semiconducteur de type N, et un deuxième matériau thermoélectrique MP, typiquement un semiconducteur de type P. Des premières extrémités des matériaux thermoélectriques MN, Mp, sont interconnectées et reliées thermiquement à une tête chaude TEh. Des deuxièmes extrémités des matériaux thermoélectriques MN, MP, sont reliées thermiquement à une tête froide TEC et connectées respectivement à des bornes électriques positive B+ et négative B-. Les têtes chaude et froide TEH, TEC, sont ici chauffée et refroidie par des liquides caloporteurs chaud et froid provenant d’échangeurs thermiques chaud EXH et froid EXC qui forment des sources froide et chaude, respectivement. C'est le gradient de température GT imposé par les têtes chaude TEH et froide TEC dans les matériaux thermoélectriques MN, MP, qui produit par effet Siebeck une différence de potentiel V entre les bornes électriques B+ et B-. The thermoelectric module TE comprises a first thermoelectric material M n , typically an N type semiconductor, and a second thermoelectric material MP, typically a P type semiconductor. First ends of the thermoelectric materials MN, M p , are interconnected and thermally connected to a TE hot head h . Second ends of the thermoelectric materials M N , M P , are thermally connected to a cold head TE C and connected respectively to positive electrical terminals B + and negative B-. The TE H and TE C hot and cold heads are here heated and cooled by hot and cold heat transfer liquids from EX H hot and EX C cold heat exchangers which form cold and hot sources, respectively. It is the temperature gradient GT imposed by the hot TE H and cold TE C heads in the thermoelectric materials M N , M P , which produces by Siebeck effect a potential difference V between the electrical terminals B + and B-.
[006] Dans d’autres réalisations, la chaleur pourra être amenée à la tête chaude TEH par des caloducs utilisant des fluides diphasiques ou bien par un contact direct entre des gaz de combustion chauds. La tête froide TEC pourra être refroidie par l’air ambient ou un circuit de liquide caloporteur. In other embodiments, the heat can be brought to the TE H hot head by heat pipes using two-phase fluids or by direct contact between hot combustion gases. The TE C cold head can be cooled by ambient air or a heat transfer liquid circuit.
[007] Le dispositif de combustion CO comprend un souffleur d’air BL, une chambre de combustion CH et l’échangeur thermique chaud EXH. Le souffleur d’air BL est chargé de puiser l’air entrant AIR vers la chambre de combustion CH. Un carburant est injecté dans la chambre de combustion CH pour y être brûlé et produire de la chaleur. Des gaz de combustion EG sortant de la chambre de combustion CH traversent l’échangeur thermique chaud EXH et y cèdent des calories avant d’être évacués à l’extérieur. The CO combustion device comprises an air blower BL, a combustion chamber CH and the hot heat exchanger EX H. The BL air blower is responsible for drawing the incoming air AIR towards the combustion chamber CH. A fuel is injected into the CH combustion chamber to be burned there and produce heat. Combustion gases EG leaving the combustion chamber CH pass through the hot heat exchanger EX H and release calories there before being evacuated outside.
[008] De manière générale, les machines thermoélectriques à combustion externe, telles que la machine MTE décrite ci-dessus, possèdent un rendement thermodynamique de cycle, c’est-à-dire, un travail net généré par rapport à la quantité de chaleur fournie au cycle, qui dépend du facteur de mérite ZT. Si on considère le rendement global de la machine, c’est-à-dire, le travail net généré par rapport à l’énergie consommée dans la chambre de combustion, celui-ci est faible car une grande part de l’énergie apportée par la combustion du carburant part vers l’extérieur avec les gaz de combustion et du fait que le facteur de mérite ZT a une valeur qui est souvent limitée.
[009] Il est connu d’utiliser un régénérateur thermique ou récupérateur de chaleur pour récupérer des calories dans les gaz de combustion avant l’évacuation de ceux-ci vers l’extérieur. Les calories récupérées par le régénérateur sont transférées vers l’entrée d’air de la chambre de combustion afin d’accroître la température de l’air entrant et réduire ainsi la quantité de carburant injectée dans la chambre de combustion. Il est connu également d’intégrer plusieurs modules thermoélectriques en série dans la machine thermoélectrique. In general, thermoelectric machines with external combustion, such as the MTE machine described above, have a thermodynamic cycle efficiency, that is to say, a net work generated compared to the amount of heat. provided to the cycle, which depends on the merit factor ZT. If we consider the overall efficiency of the machine, that is to say, the net work generated compared to the energy consumed in the combustion chamber, it is low because a large part of the energy provided by the combustion of the fuel goes outside with the combustion gases and the fact that the merit factor ZT has a value which is often limited. It is known to use a thermal regenerator or heat recovery to recover calories in the combustion gases before the evacuation thereof to the outside. The calories recovered by the regenerator are transferred to the air inlet of the combustion chamber in order to increase the temperature of the incoming air and thus reduce the amount of fuel injected into the combustion chamber. It is also known to integrate several thermoelectric modules in series in the thermoelectric machine.
[0010] Les solutions de la technique antérieure mentionnées ci-dessus apportent une amélioration du rendement global de la machine thermoélectrique, mais celui-ci reste cependant insuffisant, notamment pour des applications dans la traction d’un véhicule automobile. De plus, la densité de puissance que peuvent offrir les machines thermoélectriques de la technique antérieure reste faible. The solutions of the prior art mentioned above provide an improvement in the overall efficiency of the thermoelectric machine, but it remains insufficient, in particular for applications in the traction of a motor vehicle. In addition, the power density that the thermoelectric machines of the prior art can offer remains low.
[001 1 ] Il existe donc un besoin pour une machine thermoélectrique ayant une architecture perfectionnée capable d’offrir un meilleur rendement énergétique. [001 1] There is therefore a need for a thermoelectric machine having an improved architecture capable of offering better energy efficiency.
[0012] Selon un premier aspect, l’invention concerne une machine thermoélectrique comprenant un générateur thermoélectrique comportant des premier et deuxième modules thermoélectriques agencés en série à l’intérieur du générateur thermoélectrique, des premier et deuxième échangeurs chauds raccordés en série dans un circuit de circulation de gaz de combustion et raccordés respectivement aux premier et deuxième modules thermoélectriques de façon à chauffer ceux-ci, des premier et deuxième échangeurs froids raccordés respectivement aux premier et deuxième modules thermoélectriques de façon à refroidir ceux-ci, et une première chambre de combustion alimentée en air et en carburant et assurant une première combustion produisant des gaz de combustion circulant dans le circuit de circulation de gaz de combustion. Conformément à l’invention, la machine thermoélectrique comprend également une deuxième chambre de combustion insérée entre les premier et deuxième échangeurs chauds dans le circuit de circulation de gaz de combustion, la deuxième chambre de combustion étant alimentée en carburant et assurant une post combustion de réchauffage des gaz de combustion. According to a first aspect, the invention relates to a thermoelectric machine comprising a thermoelectric generator comprising first and second thermoelectric modules arranged in series inside the thermoelectric generator, first and second hot exchangers connected in series in a circuit circulation of combustion gases and connected respectively to the first and second thermoelectric modules so as to heat them, first and second cold exchangers connected respectively to the first and second thermoelectric modules so as to cool them, and a first combustion chamber supplied with air and fuel and ensuring a first combustion producing combustion gases circulating in the combustion gas circulation circuit. In accordance with the invention, the thermoelectric machine also includes a second combustion chamber inserted between the first and second hot exchangers in the combustion gas circulation circuit, the second combustion chamber being supplied with fuel and providing post combustion for reheating. combustion gases.
[0013] Selon une caractéristique particulière, la combustion dans la première chambre de combustion est réglée pour être non stoechiométrique et produire un excès d’air dans les gaz de combustion. La combustion non stoechiométrique limite la température maximale à une valeur compatible avec les limites métallurgiques des matériaux de la chambre de combustion.
[0014] Selon une autre caractéristique particulière, le générateur thermoélectrique comporte un troisième module thermoélectrique agencé en série avec le deuxième module thermoélectrique à l’intérieur du générateur thermoélectrique, et la machine thermoélectrique comprend un troisième échangeur chaud raccordé dans le circuit de circulation de gaz de combustion, en aval du deuxième échangeur chaud, et raccordé au troisième module thermoélectrique, un troisième échangeur froid raccordé au troisième module thermoélectrique, et une troisième chambre de combustion insérée entre les deuxième et troisième échangeurs chauds dans le circuit de circulation de gaz de combustion, la troisième chambre de combustion étant alimentée en carburant et assurant une post combustion de réchauffage des gaz de combustion. According to a particular characteristic, the combustion in the first combustion chamber is adjusted to be non-stoichiometric and to produce an excess of air in the combustion gases. Non-stoichiometric combustion limits the maximum temperature to a value compatible with the metallurgical limits of the materials of the combustion chamber. According to another particular characteristic, the thermoelectric generator comprises a third thermoelectric module arranged in series with the second thermoelectric module inside the thermoelectric generator, and the thermoelectric machine comprises a third hot exchanger connected in the gas circulation circuit combustion, downstream of the second hot exchanger, and connected to the third thermoelectric module, a third cold exchanger connected to the third thermoelectric module, and a third combustion chamber inserted between the second and third hot exchangers in the circuit for circulation of combustion gas , the third combustion chamber being supplied with fuel and providing post combustion for heating the combustion gases.
[0015] Selon encore une autre caractéristique particulière, la combustion dans la deuxième chambre de combustion est réglée pour être non stoechiométrique et produire un excès d’air dans les gaz de combustion. According to yet another particular characteristic, the combustion in the second combustion chamber is adjusted to be non-stoichiometric and to produce an excess of air in the combustion gases.
[0016] Selon encore une autre caractéristique particulière, la machine thermoélectrique comprend également un régénérateur thermique assurant un préchauffage de l’air entrant avec des calories récupérées dans les gaz de combustion avant l’évacuation de ceux-ci vers l’extérieur. According to yet another particular characteristic, the thermoelectric machine also comprises a thermal regenerator ensuring preheating of the incoming air with calories recovered in the combustion gases before the evacuation of these to the outside.
[0017] Selon encore une autre caractéristique particulière, la machine thermoélectrique comprend également un souffleur d’air produisant un air entrant pulsé. According to yet another particular characteristic, the thermoelectric machine also includes an air blower producing pulsed incoming air.
[0018] Selon un autre aspect, l’invention concerne aussi un système de cogénération d’énergie comprenant une machine thermoélectrique telle que décrite brièvement ci-dessus. According to another aspect, the invention also relates to an energy cogeneration system comprising a thermoelectric machine as briefly described above.
[0019] Selon encore un autre aspect, l’invention concerne aussi un prolongateur d’autonomie pour véhicule électrique ou électrique hybride comprenant une machine thermoélectrique telle que décrite brièvement ci-dessus. According to yet another aspect, the invention also relates to a range extender for an electric or hybrid electric vehicle comprising a thermoelectric machine as briefly described above.
[0020] Selon encore un autre aspect, l’invention concerne un véhicule comprenant une machine thermoélectrique telle que décrite brièvement ci-dessus. According to yet another aspect, the invention relates to a vehicle comprising a thermoelectric machine as briefly described above.
[0021 ] D’autres avantages et caractéristiques de la présente invention apparaîtront plus clairement à la lecture de la description détaillée ci-dessous de plusieurs formes de réalisation particulières de l’invention en référence aux dessins annexés, dans lesquels :
- la Fig.1 est un bloc-diagramme d’une machine thermoélectrique de la technique antérieure ; Other advantages and characteristics of the present invention will appear more clearly on reading the detailed description below of several particular embodiments of the invention with reference to the accompanying drawings, in which: - Fig.1 is a block diagram of a thermoelectric machine of the prior art;
- la Fig.2 est un bloc-diagramme d’une première forme de réalisation de la machine thermoélectrique selon l’invention, comprenant deux modules thermoélectriques ; - Fig.2 is a block diagram of a first embodiment of the thermoelectric machine according to the invention, comprising two thermoelectric modules;
- la Fig.3 est un bloc-diagramme d’une deuxième forme de réalisation de la machine thermoélectrique selon l’invention, comprenant trois modules thermoélectriques ; et - Fig.3 is a block diagram of a second embodiment of the thermoelectric machine according to the invention, comprising three thermoelectric modules; and
- la Fig.4 est un graphique comparatif montrant des diagrammes de Pareto de performances, pour des machines thermoélectriques selon la présente invention et des machines thermoélectriques de la technique antérieure. - Fig.4 is a comparative graph showing Pareto performance diagrams, for thermoelectric machines according to the present invention and thermoelectric machines of the prior art.
[0022] En référence à Fig.2, il est maintenant décrit ci-dessous une forme de réalisation particulière MTE1 d’une machine thermoélectrique selon l’invention. La machine thermoélectrique MTE1 est ici un convertisseur primaire d’énergie qui fournit de l’énergie électrique et de la chaleur à partir de la combustion externe d’un carburant. Referring to Fig.2, there is now described below a particular embodiment MTE1 of a thermoelectric machine according to the invention. The MTE1 thermoelectric machine is here a primary energy converter which supplies electrical energy and heat from the external combustion of a fuel.
[0023] Comme visible à la Fig.2, la machine thermoélectrique MTE1 comprend notamment un générateur thermoélectrique GTE1 , un dispositif de combustion-régénération CR, des premier et deuxième échangeurs EX1 H, EX2H, dits « chauds » et des premier et deuxième échangeurs EX1 C, EX2C, dits « froids ». Le générateur thermoélectrique GTE1 et les échangeurs EX1 C, EX2C, fournissent de l’énergie électrique et de la chaleur, en cogénération. As shown in Fig.2, the thermoelectric machine MTE1 includes in particular a thermoelectric generator GTE1, a combustion-regeneration device CR, first and second exchangers EX1 H , EX2 H , called "hot" and first and second exchangers EX1 C , EX2 C , called "cold". The thermoelectric generator GTE1 and the exchangers EX1 C , EX2 C , supply electrical energy and heat, in cogeneration.
[0024] Le générateur GTE1 comporte ici deux modules thermoélectriques TE1 et TE2. Les premier et deuxième modules thermoélectriques TE1 et TE2 sont raccordés respectivement aux premiers échangeurs chaud EX1 H et froid EX1 C et aux deuxièmes échangeurs chaud EX2H et froid EX2C. Chaque module thermoélectrique TE1 , TE2, comporte les matériaux thermoélectriques MN, MP, avec des têtes chaude TEH et froide TEC à leurs extrémités. The generator GTE1 here comprises two thermoelectric modules TE1 and TE2. The first and second thermoelectric modules TE1 and TE2 are connected respectively to the first heat exchangers EX1 H and cold EX1 C and to the second heat exchangers EX2 H and cold EX2 C. Each thermoelectric module TE1, TE2, comprises the thermoelectric materials M N , M P , with hot TE H and cold TE C heads at their ends.
[0025] Le dispositif de combustion-régénération CR comprend ici essentiellement un souffleur d’air BL, un régénérateur thermique REG, un ensemble de combustion EH et les premier et deuxième échangeurs chauds EX1 H et EX2H.
[0026] Le régénérateur thermique REG est un récupérateur de chaleur qui participe à l’amélioration du rendement global de la machine en permettant un préchauffage de l’air entrant AIR. Le régénérateur REG récupère des calories dans des gaz de combustion EG2 avant l’évacuation de ceux-ci vers l’extérieur sous la forme de gaz d’échappement EG3. Les calories récupérées sont utilisées pour chauffer l’air entrant AIR qui est pulsé par le souffleur d’air BL. The combustion-regeneration device CR here essentially comprises an air blower BL, a thermal regenerator REG, a combustion assembly EH and the first and second hot exchangers EX1 H and EX2 H. REG thermal regenerator is a heat recuperator which contributes to improving the overall performance of the machine by allowing preheating of the incoming air AIR. Regenerator REG recovers calories from combustion gases EG2 before their evacuation to the outside in the form of exhaust gases EG3. The calories recovered are used to heat the incoming air AIR which is pulsed by the BL air blower.
[0027] Contrairement aux machines thermoélectriques connues dans lesquelles la combustion est réalisée dans une seule chambre de combustion, la présente invention fait appel à plusieurs chambres de combustion pour la production de la chaleur. Ainsi, dans cette forme de réalisation particulière, l’ensemble de combustion EH comprend deux chambres de combustion, à savoir, une première chambre CH1 et une deuxième chambre CH2. Unlike known thermoelectric machines in which combustion is carried out in a single combustion chamber, the present invention uses several combustion chambers for the production of heat. Thus, in this particular embodiment, the combustion unit EH comprises two combustion chambers, namely, a first chamber CH1 and a second chamber CH2.
[0028] La première chambre de combustion CH1 est située directement en aval du régénérateur REG. La première chambre de combustion CH1 reçoit en entrée l’air pulsé AIR qui a été chauffé par le régénérateur REG. Du carburant est injecté dans la première chambre de combustion CH1 et la combustion de celui-ci produit des gaz de première combustion EG1 . Le premier échangeur chaud EX1 H, disposé directement en aval de la première chambre de combustion CH1 , est traversé par les gaz EG1 qui y cèdent des calories. The first combustion chamber CH1 is located directly downstream of the REG regenerator. The first combustion chamber CH1 receives as input the pulsed air AIR which has been heated by the regenerator REG. Fuel is injected into the first combustion chamber CH1 and the combustion of this produces first combustion gases EG1. The first hot exchanger EX1 H , disposed directly downstream of the first combustion chamber CH1, is crossed by the gases EG1 which release calories there.
[0029] La deuxième chambre de combustion CH2 est située directement en aval du premier échangeur chaud EX1 H et assure une post combustion. La deuxième chambre de combustion CH2 reçoit en entrée les gaz de première combustion EG1 qui ont été refroidis en traversant le premier échangeur chaud EX1 H. Du carburant est injecté dans la deuxième chambre de combustion CH2 et la combustion de celui-ci produit des gaz de post combustion EG2. Le deuxième échangeur chaud EX2H, disposé directement en aval de la deuxième chambre de combustion CH2, est traversé par les gaz EG2 qui y cèdent des calories. Les gaz EG2, refroidis par la traversée du deuxième échangeur chaud EX2H, traversent ensuite le régénérateur REG avant d’être évacués vers l’extérieur sous la forme des gaz d’échappement EG3. The second combustion chamber CH2 is located directly downstream of the first hot exchanger EX1 H and provides post combustion. The second combustion chamber CH2 receives as input the first combustion gases EG1 which have been cooled by passing through the first hot exchanger EX1 H. Fuel is injected into the second combustion chamber CH2 and the combustion of this produces post-combustion gases EG2. The second hot exchanger EX2 H , disposed directly downstream of the second combustion chamber CH2, is traversed by the gases EG2 which transfer calories there. The gases EG2, cooled by passing through the second hot exchanger EX2 H , then pass through the regenerator REG before being discharged to the outside in the form of the exhaust gases EG3.
[0030] Dans la présente invention, la deuxième chambre de combustion CH2 permet de réaliser une réchauffe intermédiaire des gaz de combustion entre les première et deuxième échangeurs chauds EX1 H et EX2H. Cette réchauffe des gaz de combustion permet de réduire la différence de température entre les premier et deuxième modules
thermoélectriques TE1 et TE2. Avantageusement, la réchauffe des gaz de combustion est déterminée de façon à ce que les deux modules thermoélectriques TE1 et TE2 opèrent au même niveau de température. Les modules thermoélectriques TE1 et TE2 ont alors un fonctionnement identique et la complexité de la machine est réduite. In the present invention, the second combustion chamber CH2 allows for intermediate heating of the combustion gases between the first and second hot exchangers EX1 H and EX2 H. This heating of the combustion gases makes it possible to reduce the temperature difference between the first and second modules. thermoelectric TE1 and TE2. Advantageously, the heating of the combustion gases is determined so that the two thermoelectric modules TE1 and TE2 operate at the same temperature level. The TE1 and TE2 thermoelectric modules then operate identically and the complexity of the machine is reduced.
[0031 ] Dans cette forme de réalisation particulière, la combustion dans la première chambre de combustion CH1 est réglée de façon à avoir un excès d’air dans les gaz de combustion EG1 sortants (combustion non stoechiométrique), ce qui réduit la température de combustion dans chambre et permet de respecter la limite métallurgique de tenue en température des matériaux de celle-ci. L’excès d’air présent dans les gaz de combustion EG1 permet la post combustion de réchauffage dans la deuxième chambre de combustion CH2. La combustion non stoechiométrique dans la première chambre de combustion CH1 offre l’avantage d’une température de combustion plus basse par rapport à une combustion non stoechiométrique, ce qui réduit les contraintes sur les matériaux de la chambre CH1 . On notera cependant que des variantes de réalisation sont possibles tout en restant le cadre de l’invention. Ainsi, par exemple, dans certaines applications, la combustion dans la première chambre de combustion CH1 sera stoechiométrique et l’homme du métier prévoira un apport d’air dans la deuxième chambre de combustion CH2 pour y obtenir une combustion satisfaisante, et une production de chaleur suffisante pour le réchauffage. In this particular embodiment, the combustion in the first combustion chamber CH1 is adjusted so as to have an excess of air in the outgoing combustion gases EG1 (non stoichiometric combustion), which reduces the combustion temperature in a room and makes it possible to comply with the metallurgical limit of temperature resistance of the materials thereof. The excess air present in the combustion gases EG1 allows the post combustion to reheat in the second combustion chamber CH2. Non-stoichiometric combustion in the first CH1 combustion chamber offers the advantage of a lower combustion temperature compared to non-stoichiometric combustion, which reduces the stresses on the materials of the CH1 chamber. It should be noted, however, that alternative embodiments are possible while remaining within the scope of the invention. Thus, for example, in certain applications, the combustion in the first combustion chamber CH1 will be stoichiometric and the skilled person will provide an air supply in the second combustion chamber CH2 to obtain satisfactory combustion therein, and a production of sufficient heat for reheating.
[0032] Le préchauffage de l’air entrant AIR assuré par le régénérateur REG en amont de la première chambre de combustion CH1 n’est pas indispensable à la mise en oeuvre de l’invention. Cependant, outre son effet positif sur l’amélioration du rendement global de la machine, le préchauffage par le régénérateur REG conduit à une moindre quantité de carburant injectée dans la chambre, ce qui favorise une quantité d’oxygène accrue dans les gaz de combustion EG1 pour la post combustion de réchauffage. The preheating of the incoming air AIR provided by the REG regenerator upstream of the first combustion chamber CH1 is not essential for the implementation of the invention. However, in addition to its positive effect on improving the overall efficiency of the machine, preheating by the REG regenerator leads to a lesser amount of fuel injected into the chamber, which promotes an increased amount of oxygen in the combustion gases EG1 for reheating after combustion.
[0033] Comparativement à une machine thermoélectrique de la technique antérieure, le générateur thermoélectrique selon l’invention permet une réduction des oxydes d’azote (NOx) à la source. En effet, l’abaissement de la température dans la première chambre CH1 par une combustion non stoechiométrique et la post combustion de réchauffage assurée dans la deuxième chambre CH2 limitent la production des NOx avec des carburants tels que l’essence, le gasoil ou le fioul. La température basse dans la première chambre CH1 favorise une moindre production de NOx et la post combustion assurée dans la deuxième chambre CH2 brûle ceux-ci, de manière analogue à ce qui se produit dans un moteur thermique équipé d’une vanne EGR de recirculation des gaz d’échappement.
[0034] L’invention ne se limite pas à une machine thermoélectrique ayant deux modules thermoélectriques et est aussi applicable dans des machines ayant trois modules thermoélectriques et plus. La machine thermoélectrique selon l’invention pourra ainsi comprendre deux chambres de combustion ou plus pour des réchauffages intermédiaires des gaz de combustion qui alimentent en chaleur les modules thermoélectriques. Compared to a thermoelectric machine of the prior art, the thermoelectric generator according to the invention allows a reduction of nitrogen oxides (NOx) at the source. Indeed, the lowering of the temperature in the first chamber CH1 by a non-stoichiometric combustion and the post combustion combustion provided in the second chamber CH2 limit the production of NOx with fuels such as petrol, diesel or fuel oil. . The low temperature in the first chamber CH1 favors a lower production of NOx and the post combustion ensured in the second chamber CH2 burns these, in a similar manner to what occurs in a heat engine equipped with an EGR valve for recirculating the exhaust gas. The invention is not limited to a thermoelectric machine having two thermoelectric modules and is also applicable in machines having three and more thermoelectric modules. The thermoelectric machine according to the invention may thus comprise two or more combustion chambers for intermediate reheating of the combustion gases which supply heat to the thermoelectric modules.
[0035] Un exemple d’architecture d’une machine thermoélectrique MTE2 selon l’invention à trois modules thermoélectriques est montré à la Fig.3. Comme visible à la Fig.3, par rapport à la machine MTE1 de la Fig.2, la machine MTE2 comporte un générateur GTE2 ayant un module thermoélectrique supplémentaire TE3 auquel est associée une chambre de combustion supplémentaire CH3 et des échangeurs chaud EX3H et froid EX3c. La chambre de combustion CH3 assure le réchauffage des gaz de combustion entre les échangeurs chauds EX2H et EX3H, de manière analogue à la chambre de combustion CH2 entre les échangeurs chauds EX1 H et EX2H, comme déjà décrit en référence à la Fig.2. Dans cette forme de réalisation particulière, la post combustion dans la deuxième chambre CH2 est faite avec excès d’air de manière à conserver de l’oxygène pour la post combustion dans la troisième chambre CH3. An example of architecture of a MTE2 thermoelectric machine according to the invention with three thermoelectric modules is shown in Fig.3. As shown in Fig. 3, compared to the machine MTE1 in Fig. 2, the machine MTE2 comprises a generator GTE2 having an additional thermoelectric module TE3 with which is associated an additional combustion chamber CH3 and heat exchangers EX3H and cold EX3c . The combustion chamber CH3 heats the combustion gases between the hot exchangers EX2 H and EX3H, in a similar manner to the combustion chamber CH2 between the hot exchangers EX1 H and EX2 H , as already described with reference to Fig. 2 . In this particular embodiment, the post combustion in the second chamber CH2 is made with excess air so as to conserve oxygen for the post combustion in the third chamber CH3.
[0036] Par rapport à la technique antérieure, la présente invention offre un accroissement de l’ordre dix à quinze points en pourcentage sur le rendement global du générateur thermoélectrique et une densité de puissance multipliée par un facteur compris entre deux et trois. Compared to the prior art, the present invention offers an increase of the order of ten to fifteen percentage points on the overall efficiency of the thermoelectric generator and a power density multiplied by a factor of between two and three.
[0037] Une comparaison de performances, entre des machines thermoélectriques de la technique antérieure et des machines thermoélectriques selon la présente invention, est apportée par le graphique de la Fig.4 qui représente, pour une température de combustion de 1250°C, des diagrammes de Pareto du travail net spécifique ou densité de puissance (noté TNS) en kilojoule/kilogramme par rapport au rendement énergétique (noté RM) de la machine. Cette comparaison est réalisée pour des machines thermoélectriques avec des matériaux thermoélectriques ayant des facteurs de mérite ZTi=1 et ZT4=4. A comparison of performance, between thermoelectric machines of the prior art and thermoelectric machines according to the present invention, is provided by the graph in Fig.4 which represents, for a combustion temperature of 1250 ° C, diagrams of Pareto of the specific net work or power density (denoted TNS) in kilojoule / kilogram compared to the energy efficiency (denoted RM) of the machine. This comparison is carried out for thermoelectric machines with thermoelectric materials having merit factors ZTi = 1 and ZT 4 = 4.
[0038] Les machines thermoélectriques TE de la technique antérieure considérées dans le graphique de la Fig.4 sont les suivantes : TE(n1 )i à TE(n3)i et TE(R/n1 )i à TE(R/n3)i qui ont des matériaux thermoélectriques avec le facteur de mérite ZT 1 = 1 , et TE(n1 )4 à TE(n3) et TE(R/n1 )4 à TE(R/n3) qui ont des matériaux thermoélectriques avec le facteur de mérite ZT4=4. Les machines TE(n1 )i à TE(n3)i , TE(n1 )4 à TE(n3) , sont des machines sans régénérateur ayant respectivement 1 à 3 modules thermoélectriques. Les machines
TE(R/n1 )i à TE(R/n3)i , TE(R/n1 )4 à TE(R/n3)4, sont des machines avec régénérateur ayant respectivement 1 à 3 modules thermoélectriques. TE thermoelectric machines of the prior art considered in the graph of Fig.4 are as follows: TE (n1) i to TE (n3) i and TE (R / n1) i to TE (R / n3) i who have thermoelectric materials with the merit factor ZT 1 = 1, and TE (n1) 4 to TE (n3) and TE (R / n1) 4 to TE (R / n3) who have thermoelectric materials with the factor of merit ZT 4 = 4. The machines TE (n1) i to TE (n3) i, TE (n1) 4 to TE (n3), are machines without regenerator having respectively 1 to 3 thermoelectric modules. Machines TE (R / n1) i to TE (R / n3) i, TE (R / n1) 4 to TE (R / n3) 4 , are machines with regenerator having respectively 1 to 3 thermoelectric modules.
[0039] Les machines thermoélectriques TE-Re selon la présente invention considérées dans le graphiques de la Fig.4 sont les suivantes : TE-Re(n2)i , TE-Re(n3)i , TE-Re(R/n2)i et TE-Re(R/n3)i qui ont des matériaux thermoélectriques avec le facteur de mérite ZT 1 = 1 , et TE-Re(n2)4, TE-Re(n3) , TE-Re(R/n2)4, et TE-Re(R/n3) qui ont des matériaux thermoélectriques avec le facteur de mérite ZT4=4. Les machines thermoélectriques TE-Re comprennent toutes des chambres de combustion de réchauffage (Re) entre les modules thermoélectriques, comme décrit ci-dessus en référence aux Figs.2 et 3. Les machines TE- Re(n2)i et TE-Re(n3)i , TE-Re(n2)4 et TE-Re(n3) , sont des machines sans régénérateur ayant respectivement 2 et 3 modules thermoélectriques. Les machines TE-Re(R/n2)i et TE- Re(R/n3)i , TE-Re(R/n2)4 et TE-Re(R/n3) , sont des machines avec régénérateur ayant respectivement 2 et 3 modules thermoélectriques, comme celles montrées aux Figs.2 et 3. TE-Re thermoelectric machines according to the present invention considered in the graphs of Fig.4 are as follows: TE-Re (n2) i, TE-Re (n3) i, TE-Re (R / n2) i and TE-Re (R / n3) i which have thermoelectric materials with the merit factor ZT 1 = 1, and TE-Re (n2) 4 , TE-Re (n3), TE-Re (R / n2) 4 , and TE-Re (R / n3) which have thermoelectric materials with the merit factor ZT 4 = 4. The TE-Re thermoelectric machines all include heating combustion chambers (Re) between the thermoelectric modules, as described above with reference to Figs. 2 and 3. The TE- Re (n2) i and TE-Re machines ( n3) i, TE-Re (n2) 4 and TE-Re (n3), are machines without regenerator having respectively 2 and 3 thermoelectric modules. The machines TE-Re (R / n2) i and TE-Re (R / n3) i, TE-Re (R / n2) 4 and TE-Re (R / n3), are machines with regenerator having respectively 2 and 3 thermoelectric modules, like those shown in Figs. 2 and 3.
[0040] Le graphique de la Fig.4 montre bien les accroissements significatifs de rendement et de densité de puissance apportés par les machines thermoélectriques TE-Re selon l’invention par rapport aux machines thermoélectriques TA de la technique antérieure. The graph in Fig.4 clearly shows the significant increases in efficiency and power density provided by the TE-Re thermoelectric machines according to the invention compared to the TA thermoelectric machines of the prior art.
[0041 ] Les machines thermoélectriques selon l’invention sont envisageables pour des applications dans les chaînes de traction des véhicules de transport notamment dans les véhicules électriques hybrides de type hybride série, hybride parallèle et hybride série - parallèle, en particulier dans un contexte de zéro émission de C02 et de durcissement des normes environnementales. On notera que les machines thermoélectriques selon l’invention sont applicables aussi en tant que prolongateur d’autonomie pour les véhicules électriques et électriques hybrides. The thermoelectric machines according to the invention can be envisaged for applications in the traction chains of transport vehicles, in particular in hybrid electric vehicles of the series hybrid, parallel hybrid and series - parallel hybrid type, in particular in a context of zero. emission of C0 2 and hardening of environmental standards. It will be noted that the thermoelectric machines according to the invention are also applicable as a range extender for electric and electric hybrid vehicles.
[0042] Les machines thermoélectriques étant du type à combustion externe, elles sont compatibles avec tous les types de carburant qui comprennent l’essence, le gasoil, le fioul et autres, mais aussi l’hydrogène, le méthane, des combustibles solides tels que le bois, l’aluminium, le fer, le magnésium et autres. The thermoelectric machines being of the external combustion type, they are compatible with all types of fuel which include petrol, diesel, fuel oil and the like, but also hydrogen, methane, solid fuels such as wood, aluminum, iron, magnesium and others.
[0043] De manière générale, les machines thermoélectriques selon l’invention trouveront aussi des applications dans des systèmes de cogénération d’énergie, notamment dans les véhicules hybrides, les poids lourds, le domaine spatial et autres.
[0044] L’invention ne se limite pas aux formes de réalisation particulières qui ont été décrites ici à titre d’exemple. L’homme du métier, selon les applications de l’invention, pourra apporter différentes modifications et variantes entrant dans le champ de protection de l’invention.
In general, the thermoelectric machines according to the invention will also find applications in energy cogeneration systems, in particular in hybrid vehicles, heavy goods vehicles, the space sector and others. The invention is not limited to the particular embodiments which have been described here by way of example. Those skilled in the art, depending on the applications of the invention, can make different modifications and variants falling within the protective field of the invention.
Claims
1. Machine thermoélectrique (MTE1 ) comprenant un générateur thermoélectrique (GTE1 ) comportant des premier et deuxième modules thermoélectriques (TE1 , TE2) agencés en série à l’intérieur dudit générateur thermoélectrique (GTE1 ), des premier et deuxième échangeurs chauds (EX1 H, EX2H) raccordés en série dans un circuit de circulation de gaz de combustion et raccordés respectivement auxdits premier et deuxième modules thermoélectriques (TE1 , TE2) de façon à chauffer ceux-ci, des premier et deuxième échangeurs froids (EX1 C, EX2C) raccordés respectivement auxdits premier et deuxième modules thermoélectriques (TE1 , TE2) de façon à refroidir ceux-ci, et une première chambre de combustion (CH1 ) alimentée en air (AIR) et en carburant et assurant une première combustion produisant des gaz de combustion (EG1 ) circulant dans ledit circuit de circulation de gaz de combustion, caractérisée en ce qu’elle comprend également une deuxième chambre de combustion (CH2) insérée entre lesdits premier et deuxième échangeurs chauds (EX1 H, EX2h) dans ledit circuit de circulation de gaz de combustion, ladite deuxième chambre de combustion (CH2) étant alimentée en carburant et assurant une post combustion de réchauffage desdits gaz de combustion (EG1 , EG2). 1. Thermoelectric machine (MTE1) comprising a thermoelectric generator (GTE1) comprising first and second thermoelectric modules (TE1, TE2) arranged in series inside said thermoelectric generator (GTE1), first and second hot exchangers (EX1 H , EX2 H ) connected in series in a combustion gas circulation circuit and connected respectively to said first and second thermoelectric modules (TE1, TE2) so as to heat these, the first and second cold exchangers (EX1 C , EX2 C ) connected respectively to said first and second thermoelectric modules (TE1, TE2) so as to cool them, and a first combustion chamber (CH1) supplied with air (AIR) and fuel and ensuring a first combustion producing combustion gases ( EG1) circulating in said combustion gas circulation circuit, characterized in that it also comprises a second combustion chamber mbustion (CH2) inserted between said first and second hot exchangers (EX1 H, EX2 h ) in said combustion gas circulation circuit, said second combustion chamber (CH2) being supplied with fuel and providing post combustion for heating of said gases combustion (EG1, EG2).
2. Machine thermoélectrique (MTE1 ) selon la revendication 1 , caractérisée en ce que la combustion dans ladite première chambre de combustion (CH1 ) est réglée pour être non stoechiométrique et produire un excès d’air dans lesdits gaz de combustion. 2. Thermoelectric machine (MTE1) according to claim 1, characterized in that the combustion in said first combustion chamber (CH1) is adjusted to be non-stoichiometric and to produce an excess of air in said combustion gases.
3. Machine thermoélectrique (MTE2) selon la revendication 1 ou 2, caractérisé en ce que ledit générateur thermoélectrique (GTE2) comporte un troisième module thermoélectrique (TE3) agencé en série avec ledit deuxième module thermoélectrique (TE2) à l’intérieur dudit générateur thermoélectrique (GTE2), et comprenant un troisième échangeur chaud (EX3H) raccordé dans ledit circuit de circulation de gaz de combustion, en aval dudit deuxième échangeur chaud (EX2H), et raccordé audit troisième module thermoélectrique (TE3), un troisième échangeur froid (EX2C) raccordé audit troisième module thermoélectrique (TE3), et une troisième chambre de combustion (CH3) insérée entre lesdits deuxième et troisième échangeurs chauds (EX2H, EX3H) dans ledit circuit de circulation de gaz de combustion, ladite troisième chambre de combustion (CH3) étant alimentée en carburant et assurant une post combustion de réchauffage desdits gaz de combustion.
3. thermoelectric machine (MTE2) according to claim 1 or 2, characterized in that said thermoelectric generator (GTE2) comprises a third thermoelectric module (TE3) arranged in series with said second thermoelectric module (TE2) inside said thermoelectric generator (GTE2), and comprising a third hot exchanger (EX3H) connected in said combustion gas circulation circuit, downstream of said second hot exchanger (EX2 H ), and connected to said third thermoelectric module (TE3), a third cold exchanger ( EX2 C ) connected to said third thermoelectric module (TE3), and a third combustion chamber (CH3) inserted between said second and third hot exchangers (EX2 H , EX3H) in said combustion gas circulation circuit, said third combustion chamber (CH3) being supplied with fuel and ensuring post combustion of heating of said combustion gases.
4. Machine thermoélectrique (MTE2) selon la revendication 3, caractérisée en ce que la combustion dans ladite deuxième chambre de combustion (CH2) est réglée pour être non stoechiométrique et produire un excès d’air dans lesdits gaz de combustion. 4. Thermoelectric machine (MTE2) according to claim 3, characterized in that the combustion in said second combustion chamber (CH2) is adjusted to be non-stoichiometric and to produce an excess of air in said combustion gases.
5. Machine thermoélectrique selon l’une quelconque des revendications 1 à 4, caractérisée en ce qu’elle comprend également un régénérateur thermique (REG) assurant un préchauffage de l’air entrant (AIR) avec des calories récupérées dans lesdits gaz de combustion avant l’évacuation de ceux-ci vers l’extérieur. 5. Thermoelectric machine according to any one of claims 1 to 4, characterized in that it also comprises a thermal regenerator (REG) ensuring preheating of the incoming air (AIR) with calories recovered in said combustion gases before evacuation of these to the outside.
6. Machine thermoélectrique selon l’une quelconque des revendications 1 à 5, caractérisée en ce qu’elle comprend également un souffleur d’air (BL) produisant un air entrant pulsé (AIR). 6. Thermoelectric machine according to any one of claims 1 to 5, characterized in that it also comprises an air blower (BL) producing a pulsed incoming air (AIR).
7. Système de cogénération d’énergie comprenant une machine thermoélectrique selon l’une quelconque des revendications 1 à 6. 7. An energy cogeneration system comprising a thermoelectric machine according to any one of claims 1 to 6.
8. Prolongateur d’autonomie pour véhicule électrique ou électrique hybride comprenant une machine thermoélectrique selon l’une quelconque des revendications 1 à 6. 8. Range extender for an electric or hybrid electric vehicle comprising a thermoelectric machine according to any one of claims 1 to 6.
9. Véhicule comprenant une machine thermoélectrique selon l’une quelconque des revendications 1 à 6 dans sa chaîne de traction.
9. Vehicle comprising a thermoelectric machine according to any one of claims 1 to 6 in its traction chain.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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FR1857484 | 2018-08-14 | ||
FR1857484A FR3085086B1 (en) | 2018-08-14 | 2018-08-14 | THERMOELECTRIC MACHINE ESPECIALLY FOR HYBRID ELECTRIC VEHICLES WITH EXTENDED AUTONOMY |
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WO2020035642A1 true WO2020035642A1 (en) | 2020-02-20 |
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PCT/FR2019/051722 WO2020035642A1 (en) | 2018-08-14 | 2019-07-09 | Thermoelectric machine in particular for hybrid electric vehicles with extended driving range |
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Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102004016349A1 (en) * | 2003-05-09 | 2004-11-25 | Daimlerchrysler Ag | Energy extractor for motor vehicle internal combustion engine has energy converter downstream of catalytic converter and burner on exhaust pipe |
WO2005098225A1 (en) * | 2004-04-07 | 2005-10-20 | Toyota Jidosha Kabushiki Kaisha | Exhaust heat recovery power generation device and automobile equipped therewith |
WO2008095582A1 (en) | 2007-02-03 | 2008-08-14 | Bayerische Motoren Werke Aktiengesellschaft | Vehicle having a thermoelectric generator |
US20140096685A1 (en) * | 2012-10-10 | 2014-04-10 | Monika Backhaus-Ricoult | Exhaust gas treatment system including a thermoelectric generator |
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2018
- 2018-08-14 FR FR1857484A patent/FR3085086B1/en active Active
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2019
- 2019-07-09 WO PCT/FR2019/051722 patent/WO2020035642A1/en active Application Filing
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102004016349A1 (en) * | 2003-05-09 | 2004-11-25 | Daimlerchrysler Ag | Energy extractor for motor vehicle internal combustion engine has energy converter downstream of catalytic converter and burner on exhaust pipe |
WO2005098225A1 (en) * | 2004-04-07 | 2005-10-20 | Toyota Jidosha Kabushiki Kaisha | Exhaust heat recovery power generation device and automobile equipped therewith |
WO2008095582A1 (en) | 2007-02-03 | 2008-08-14 | Bayerische Motoren Werke Aktiengesellschaft | Vehicle having a thermoelectric generator |
US20140096685A1 (en) * | 2012-10-10 | 2014-04-10 | Monika Backhaus-Ricoult | Exhaust gas treatment system including a thermoelectric generator |
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FR3085086B1 (en) | 2020-08-21 |
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