EP3814611B1 - Method and device for converting thermal energy - Google Patents

Description

Technical area

The field of the invention is that of technologies for recovering heat, in particular waste industrial heat.

The invention relates in particular to a process for converting thermal energy into mechanical energy, then, preferably, into electrical energy and/or into cooling energy.

The invention also relates to a device for implementing this method.

State of the art - Technical problem

Fatal heat is the residual heat resulting from a process and not used by it (smoke, drying mist, exhaust from a heat engine, etc.)

The sources of fatal heat are very diversified. These may be energy production sites (nuclear power plants), industrial production sites, tertiary buildings which emit more heat as they consume a lot of it, such as hospitals, transport networks in closed place, or disposal sites such as thermal waste treatment units.

As far as industrial waste heat is concerned, the iron and steel, chemical, cement, food-processing and even glass sectors generate enormous quantities of heat lost by dissemination in the atmosphere.

For example, 36% of fuel consumption in industry is lost in the form of heat.

Exhaust gases are another source of waste heat.

Fatal heat represents around 50% of global energy consumption, all areas combined.

European Directive 2012/27/EU on energy efficiency makes it mandatory for waste heat emitters located near a heating network to carry out a cost-benefit analysis in order to study the possibilities of recovering fatal heat. If the solution is deemed cost-effective, it should be implemented. Similarly, any heating network project must also assess the different potentials for recovering waste heat.

• une ligne d'approvisionnement en premier fluide,
• une ligne d'approvisionnement en fluide caloporteur,
• un générateur de vapeur muni :
  • o d'une première entrée connectée à la ligne d'approvisionnement du premier fluide, le premier fluide empruntant un premier chemin entre la première entrée et une première sortie,
  • o d'une deuxième entrée recevant le fluide caloporteur, le fluide caloporteur empruntant un deuxième chemin entre la deuxième entrée et une deuxième sortie, le deuxième chemin étant distinct du premier chemin, le premier chemin étant couplé thermiquement au deuxième chemin, de manière à former de la vapeur à partir du premier fluide, ladite vapeur sortant du générateur par la première sortie,
• une chambre munie :
  • o d'une première entrée connectée à la première sortie du générateur de vapeur, le premier fluide empruntant un premier chemin dans la chambre entre la première entrée et une première sortie, la chambre étant configurée pour réaliser la détente isotherme du premier fluide dans la chambre au moyen une détente fractionnée par une pluralité de détentes élémentaires isothermes,
  • o d'une deuxième entrée connectée à la ligne d'approvisionnement en fluide caloporteur, le fluide caloporteur empruntant un deuxième chemin distinct du premier chemin entre la deuxième entrée et une deuxième sortie, la deuxième sortie de la chambre étant connecté à la deuxième entrée du générateur de vapeur,
  • Le premier chemin étant couplé thermiquement au deuxième chemin de manière à chauffer le premier fluide entre chaque détente,
• un dispositif de mélange connecté à la première sortie de la chambre et à la deuxième sortie du générateur de vapeur et configuré de manière à mélanger le premier fluide sous forme vapeur avec un fluide caloporteur pour obtenir un mélange double phase.

In this context, the patent application WO2012089940A2 describes a device for converting thermal energy into mechanical energy comprising:

• a first fluid supply line,
• a heat transfer fluid supply line,
• a steam generator equipped with:
  • o a first inlet connected to the first fluid supply line, the first fluid taking a first path between the first inlet and a first outlet,
  • o a second inlet receiving the heat transfer fluid, the heat transfer fluid taking a second path between the second inlet and a second outlet, the second path being separate from the first path, the first path being thermally coupled to the second path, so as to form steam from the first fluid, said steam exiting the generator through the first outlet,
• a room equipped with:
  • o a first inlet connected to the first outlet of the steam generator, the first fluid taking a first path in the chamber between the first inlet and a first outlet, the chamber being configured to carry out the isothermal expansion of the first fluid in the chamber by means of an expansion divided by a plurality of isothermal elementary expansions,
  • o a second inlet connected to the heat transfer fluid supply line, the heat transfer fluid taking a second path distinct from the first path between the second inlet and a second outlet, the second outlet of the chamber being connected to the second inlet of the steam generator,
  • The first path being thermally coupled to the second path so as to heat the first fluid between each expansion,
• a mixing device connected to the first outlet of the chamber and to the second outlet of the steam generator and configured so as to mix the first fluid in vapor form with a heat transfer fluid to obtain a dual-phase mixture.

The heat transfer fluid is heated by means of capturing solar energy.

The heat transfer fluid is for example oil while the first fluid is a thermodynamic flow, for example water or a water/glycerol mixture. This dual-phase mixture is a flow of heat transfer fluid in the form of oil droplets and thermodynamic fluid in the form of water vapour, at high temperature. The kinetic energy of this flow is transformed into mechanical energy by means of a turbine of the Pelton turbine type, driving an electric alternator. The oil/water mixture is recovered at the turbine outlet and the 2 fluids are separated, which are then reused in this energy conversion of heat into mechanical energy and then into electricity.

In this method and this device according to WO2012089940A2 , the heat transfer fluid is heated by a solar concentrator and then contributes to the transformation of the thermodynamic fluid into steam and then to the heating of the thermodynamic fluid between each expansion. This method and this device according to WO2012089940A2 are not specifically suitable for converting thermal energy from waste heat into electrical energy, which may have a wide temperature range. Furthermore, the performance of this method and of this known device can be improved, in particular in terms of energy efficiency and extension of the range of electrical powers generated. Document US 3,972,195A shows a thermal energy conversion method according to the state of the art. U

Objectives of the invention

• 
  L'un des objectifs essentiels de la présente invention est de fournir un procédé perfectionné de conversion d'énergie thermique, de préférence de chaleur fatale, en énergie mécanique, et, préférentiellement en énergie électrique et/ou en énergie frigorifique, le perfectionnement recherché consistant en une amélioration du rendement énergétique de la conversion.
• 
  L'un des objectifs essentiels de la présente invention est de fournir un procédé perfectionné de conversion d'énergie thermique provenant d'une source de chaleur fatale, en énergie mécanique, et, préférentiellement en énergie électrique et/ou en énergie frigorifique, le perfectionnement recherché consistant en une adaptabilité du procédé à des sources de chaleur fatale dont la température varie dans une large gamme .
• 
  L'un des objectifs essentiels de la présente invention est de fournir un procédé perfectionné de conversion d'énergie thermique, de préférence de chaleur fatale, en énergie mécanique, et, préférentiellement en énergie électrique et/ou en énergie frigorifique, qui soit économique en termes de production et de maintenance.
• 
  L'un des objectifs essentiels de la présente invention de fournir un procédé perfectionné de conversion d'énergie thermique, de préférence de chaleur fatale, en énergie mécanique, et, préférentiellement en énergie électrique et/ou en énergie frigorifique, qui soit en adéquation avec les contraintes environnementales.
• 
  L'un des objectifs essentiels de la présente invention est de fournir un dispositif industriel, fiable, performant, économique et robuste, pour la mise en oeuvre du procédé tel que visé dans l'un des objectifs ci-dessus.

In this context, the present invention aims to satisfy at least one of the objectives set out below.

• 
  One of the essential objectives of the present invention is to provide an improved process for converting thermal energy, preferably waste heat, into mechanical energy, and, preferably into electrical energy and/or cooling energy, the desired improvement consisting into an improvement in the energy efficiency of the conversion.
• 
  One of the essential objectives of the present invention is to provide an improved process for converting thermal energy originating from a waste heat source, into mechanical energy, and, preferably into electrical energy and/or cooling energy, the improvement research consisting of an adaptability of the process to sources of fatal heat whose temperature varies within a wide range.
• 
  One of the essential objectives of the present invention is to provide an improved process for converting thermal energy, preferably waste heat, into mechanical energy, and, preferably into electrical energy and/or cooling energy, which is economical in terms of production and maintenance.
• 
  One of the essential objectives of the present invention to provide an improved process for converting thermal energy, preferably waste heat, into mechanical energy, and, preferably into electrical energy and/or cooling energy, which is in line with environmental constraints.
• 
  One of the essential objectives of the present invention is to provide an industrial device that is reliable, efficient, economical and robust, for implementing the method as targeted in one of the above objectives.

Brief description of the invention

• procédé de conversion d'énergie thermique, de préférence de chaleur fatale, contenue dans un fluide au moins en partie gazeux dit fluide fatal (FF), en énergie mécanique, et, préférentiellement en énergie électrique et/ou en énergie frigorifique;
• ledit procédé mettant en oeuvre au moins un fluide thermodynamique FT et au moins un fluide caloporteur FC, dans lequel :
  1. I. on met en oeuvre un flux f ^c0 de fluide FC au moins en partie liquide;
  2. II. on transfère au flux f ^c0 de l'énergie thermique à convertir issue du fluide FF;
  3. III. on pulvérise le flux f ^c0 chauffé en (II) pour générer un flux f ^c1 fragmenté de fluide FC;
  4. IV. en parallèle, on met en oeuvre un flux f ^t0 de fluide FT au moins en partie liquide;
  5. V. puis on transfère au flux f ^t0 de fluide FT de l'énergie thermique à convertir issue du fluide FF, pour générer un flux f^t, dont la température est supérieure à celle du flux f^t0, le fluide FT du flux f^t étant:
     1. i. en phase liquide;
     2. ii. en phase liquide et en phase vapeur;
     3. iii. en phase vapeur à saturation;
     4. iv. ou en phase vapeur surchauffée ;
  6. VI. au besoin, on chauffe le flux f', pour le vaporiser de sorte que son titre en vapeur soit supérieur ou égal à 0,9; de préférence à 0,95;
  7. VII. on injecte le flux f^t dans au moins une enceinte recevant également le flux f ^c1 de fluide FC, pour former un flux mélangé biphasique f ^c1/t; le rapport Rd du débit massique du fluide FT sur le débit massique total du fluide FC et du fluide FT, étant compris entre 1 et 20%, de préférence entre 3 et 18%, et, plus préférentiellement encore entre 5 et 15 %;
  8. VIII. ce flux f ^c1/t est ensuite accéléré et détendu;
  9. IX. on convertit l'énergie cinétique de ce flux accéléré f ^c1/t en énergie mécanique; cette dernière étant éventuellement transformée en énergie électrique et/ou en énergie frigorifique;
  10. X. on sépare, d'une part, FT et, d'autre part, FC ;
  11. XI. on récupère, d'une part, un flux f ^t00 au moins en partie gazeux de FT et, d'autre part, un flux f ^c0 au moins en partie liquide de FC ;
  12. XII. on comprime et on augmente la vitesse de circulation du flux f ^c0 de FC;
  13. XIII. on condense le flux f ^t00 au moins en partie gazeux de FT en un flux f ^t0 au moins en partie liquide de FT;
  14. XIV. on comprime et on augmente la vitesse de circulation du flux f ^t0 de FT; caractérisé
      • en ce que ce procédé comprend la mise en oeuvre d'au moins une boucle de circulation de FT et d'au moins une boucle de circulation de FC;
      • ces deux boucles ayant en commun:
        1. i. au moins un Injecteur-Mélangeur-Accélérateur (IMA) dans lequel le flux et le flux f ^t sont destinés à être injectés/mélangés/accélérés;
        2. ii. au moins un convertisseur du flux accéléré f ^c1/t en énergie mécanique;
        3. iii. éventuellement au moins un transformateur de cette énergie mécanique en énergie électrique et/ou en énergie frigorifique;
        4. iv. au moins un séparateur de FT et de FC;
           • la boucle de circulation de FT comportant au moins un échangeur thermique entre FT (étape V, voire VI) et FF, au moins un condenseur de FT et au moins une pompe de mise en circulation de FT dans cette boucle;
           • la boucle de circulation de FC comportant un échangeur thermique entre FC (étape II) et FF et au moins une pompe de mise en circulation de FC dans cette boucle.

These objectives, among others, are achieved by the present invention formulated by the characteristics of claim 1 and which relates, in the first place, to a

• process for converting thermal energy, preferably waste heat, contained in an at least partly gaseous fluid called waste fluid (FF), into mechanical energy, and, preferably into electrical energy and/or into cooling energy;
• said method using at least one thermodynamic fluid FT and at least one heat transfer fluid FC, in which:
  1. I. a flow f ^c0 of FC fluid at least partly liquid is implemented;
  2. II. heat energy to be converted from the fluid FF is transferred to the flow f ^c0 ;
  3. III. the stream f ^c0 heated in (II) is sprayed to generate a fragmented stream f ^c1 of fluid FC;
  4. IV. in parallel, a flow f ^t0 of fluid FT at least partly liquid is implemented;
  5. V. then thermal energy to be converted from the fluid FF is transferred to the flow f ^t0 of fluid FT, to generate a flow f ^t , the temperature of which is higher than that of the flow f ^t0 , the fluid FT of the flow f ^t being:
     1. i. in the liquid phase;
     2. ii. in liquid phase and in vapor phase;
     3. iii. in the vapor phase at saturation;
     4. iv. or in the superheated vapor phase;
  6. VI. if necessary, the stream f' is heated to vaporize it so that its vapor content is greater than or equal to 0.9; preferably 0.95;
  7. VII. the flow f ^t is injected into at least one chamber also receiving the flow f ^c1 of fluid FC, to form a two-phase mixed flow f ^c1/t ; the ratio Rd of the mass flow rate of the fluid FT to the total mass flow rate of the fluid FC and of the fluid FT, being between 1 and 20%, preferably between 3 and 18%, and, even more preferably between 5 and 15%;
  8. VIII. this flux f ^c1/t is then accelerated and relaxed;
  9. IX. the kinetic energy of this accelerated flux f ^c1/t is converted into mechanical energy; the latter possibly being transformed into electrical energy and/or into cooling energy;
  10. X. we separate, on the one hand, FT and, on the other hand, FC;
  11. XI. one recovers, on the one hand, a flow f ^t00 at least partly gaseous of FT and, on the other hand, a flow f ^c0 at least partly liquid of FC;
  12. XII. one compresses and one increases the speed of circulation of the flow f ^c0 of FC;
  13. XIII. the stream f ^t00 at least partly gaseous of FT is condensed into a stream f ^t0 at least partly liquid of FT;
  14. XIV. the flow velocity f ^t0 of FT is compressed and increased; characterized
      • in that this method comprises the implementation of at least one FT circulation loop and at least one FC circulation loop;
      • these two loops having in common:
        1. i. at least one Injector-Mixer-Accelerator (IMA) in which the flow and the flow f ^t are intended to be injected/mixed/accelerated;
        2. ii. at least one converter of the accelerated flux f ^c1/t into mechanical energy;
        3. iii. possibly at least one transformer of this mechanical energy into electrical energy and/or into cooling energy;
        4. iv. at least one FT and FC splitter;
           • the FT circulation loop comprising at least one heat exchanger between FT (stage V, even VI) and FF, at least one FT condenser and at least one pump for circulating FT in this loop;
           • the FC circulation loop comprising a heat exchanger between FC (stage II) and FF and at least one FC circulation pump in this loop.

It is to the credit of the inventors to have imagined implementing two fluid loops: one of heat transfer fluid and one of thermodynamic fluid, each of these loops comprising means for circulating the fluid and means for recovering the waste heat. by heat exchange between the fatal fluid and the heat transfer fluid in one of the loops, or the thermodynamic fluid in the other loop.

This makes the process according to the invention a thermokinetic conversion technique which is economical, reliable, efficient, eco-compatible and with improved yield.

This improvement in the efficiency of the transformation of waste heat and mechanical energy, and preferably into electrical or cold energy, is firstly obtained by maximizing the recovery of the waste energy available by heating by exchangers on the heat flow. of a heat transfer fluid FC capturing high temperatures, supplemented by the heating of a thermodynamic fluid FT in order to capture lower temperatures. This two-fluid device makes it possible to exhaust almost all of the recoverable thermal energy.

This system has a low investment and maintenance cost.

Its simplicity, its robustness, its relatively silent nature, its ease of installation and implementation, its operation at very low pressure (1-10 bars), its safety, its respect for the environment (no pressure in the capacities, no organic fluid), its flexibility (diversity of heat sources), its modularity (several jets on the same turbine), its high percentage of waste heat recovered thanks to the 2 fluids, the fact that they produce a cold source of the order of 80° C. allowing additional recovery, its reduced installation cost, its financial profitability, are advantages among others of the system according to the invention.

This optimization of the quantity of fatal heat captured is supplemented by an optimization of the IMA (Injector-Mixer-Accelerator) device for transforming thermal energy into kinetic energy, obtained by an adapted ratio of proportion between the thermodynamic fluid FT and the fluid heat transfer fluid FC, possibly supplemented by an acceleration of the thermodynamic fluid FT upstream of its mixing with the heat transfer fluid FC. Thus, in its inventive principle, the method comprises, for the implementation of step VII, the choice of a ratio Rd of the mass flow rate of the fluid FT to the total mass flow rate of the fluid FC and of the fluid FT, is between 1 and 20%, preferably between 3 and 18%, and more preferably still between 5 and 15%.

In accordance with the invention, the thermal energy to be converted is contained in a fatal fluid FF, part of the calories of which is first transferred to FC (stage II), and of which another part of the calories is then transferred to FT for its heating and, preferably, for its vaporization (stages V and VI).

According to an advantageous embodiment of the invention, the temperature of FF at the outlet of the FC and FT heating exchangers can be advantageously adapted, before FF is evacuated outside. Indeed, when FF is loaded with solid particles, FF is evacuated outside, preferably, after having been subjected to a treatment of extraction of these solid particles by filtration, which imposes a maximum temperature of FF, in order to do not degrade the filters (typically <200°C).

Thanks to the use of 2 fluids FT and FC heated directly by the fatal fluid FF, the final temperature of the FF is adapted to the filtration constraints, if necessary, before its evacuation outside and/or to the constraints corrosion, because it is possible to optimally size the heat exchangers used in this process, and in particular the temperature of FF at the outlet of the FF/FT exchanger for heating FT.

According to an advantageous possibility of the invention, the temperature of the fluid FF at the end of stages II, V or even VI, is between 100 and 200°C and even more preferably between 180°C and 200°C. These temperature values for FF during the process increase the compatibility of the latter with a great multiplicity of industrial processes generating waste heat.

Advantageously, during step VII, the injection of the flow f ^t of the thermodynamic fluid FT into an injection chamber of the IMA takes place at a speed of between 40 and 300 m/s, preferably between 50 and 150 m /s and, even more preferably, between 60 and 100 m/s.

During step VIII, the flow f ^t is preferably accelerated and expanded in at least one chamber of suitable profile, preferably in a nozzle.

In a remarkable variant, before step VIII, the flow f ^t is subjected, during at least one step (VIII°) to pre-acceleration by expansion, preferably quasi-isothermal or polytropic, of the flow f', in at least a chamber of suitable profile, preferably in a nozzle; this step (VIII°) being advantageously implemented in the same chamber of suitable profile as that of step (VIII).

According to another innovative arrangement of the process in accordance with the invention, FT is an aqueous liquid, preferably chosen from the group comprising—ideally consisting of—water, glycerol and their mixtures. In addition, FC is chosen from vegetable or mineral oils, preferably from oils which are immiscible with water and/or which have a varnish appearance temperature greater than or equal to 200° C., preferably 300° C. C, and, more preferably still from vegetable oils; FC being ideally chosen from the group comprising -ideally composed of-: castor oil and/or olive oil.

According to a preferred characteristic of the invention, the fatal fluid FF initially has a temperature greater than or equal to 200° C. and preferably greater than or equal to 300° C., and/or is chosen from gaseous fluids and, more preferably still, in the group comprising - ideally made up of -: hot air, water vapours, engine exhaust gases, smoke, in particular industrial smoke, heat from flames and heat from dryers, or among the liquid fluids ( e . g . as is the case in concentrated solar installations).

This concerns in particular waste incinerators, installations for producing heat from biomass, industries such as steelworks, cement works, glassworks, as well as heat engines, in particular generator sets.

C2. la pression de service Pf ^t (en bars) du flux f^t avant l'injection lors de l'étape VII et après la compression du flux f ^t00 de FC à l'étape XIV, est telle que - dans un ordre croissant de préférence- : $$3\le {\mathrm{Pf}}^{\mathrm{t}}\le 30;5\le {\mathrm{Pf}}^{\mathrm{t}}\le 25;10\le {\mathrm{Pf}}^{\mathrm{t}}\le 15$$

C3. Pf ^c0 et Pf ^t sont identiques ou différentes, de préférence identiques; C4. La pression Pf ^c1/t du flux f ^c1/t après l'étape IX de conversion de l'énergie cinétique en énergie mécanique, en bars et dans un ordre croissant de préférence, est telle : $${\mathrm{Pf}}^{\mathrm{c1/t}}\le 2;\mathrm{0,3}\le {\mathrm{Pf}}^{\mathrm{c1/t}}\le \mathrm{1,5}$$

; de l'ordre de 1 bar (pression atmosphérique). The method according to the invention is distinguished in that it implements at least one of the following characteristics: C1. the operating pressure Pf ^c0 (in bars) of the flow f ^c0 before the spraying of stage III and after the compression of the flow f ^c0 of FC in stage XII, is such that - in increasing order of preference -: $$3\le {\mathrm{pf}}^{\mathrm{vs}0}\le 30;5\le {\mathrm{pf}}^{\mathrm{vs}0}\le 25;10\le {\mathrm{pf}}^{\mathrm{vs}0}\le 15$$

C2. the operating pressure Pf ^t (in bars) of the flow f ^t before the injection during stage VII and after the compression of the flow f ^t00 of FC in stage XIV, is such that - in ascending order of preference -: $$3\le {\mathrm{pf}}^{\mathrm{you}}\le 30;5\le {\mathrm{pf}}^{\mathrm{you}}\le 25;10\le {\mathrm{pf}}^{\mathrm{you}}\le 15$$

C3. Pf ^c0 and Pf ^t are identical or different, preferably identical; C4. The pressure Pf ^c1/t of the flow f ^c1/t after stage IX of conversion of kinetic energy into mechanical energy, in bars and in increasing order of preference, is such: $${\mathrm{pf}}^{\mathrm{c1/t}}\le 2;0.3\le {\mathrm{pf}}^{\mathrm{c1/t}}\le 1.5$$

; of the order of 1 bar (atmospheric pressure).

Advantageously, the size of the FC droplets making up the fragmented flow generated in step (III) is between 100 and 600 μm, preferably between 200 and 400 μm.

In a high-performance variant of the invention, it is ensured that the expansion of the flow f ^t in the enclosure of the IMA also receiving the fragmented flow f ^c1 of fluid FC, generates an acceleration effect (sometimes called the effect of trunk) caused by a motor flow, namely the flow f ^t of FT, on an aspirated flow, namely the flow f ^c1 of FC.

• particulier pour la mise en oeuvre du procédé selon l'invention, caractérisé en ce qu'il comprend au moins une boucle de circulation de FT et au moins une boucle de circulation de FC,
• ces deux boucles ayant en commun:
  1. i. au moins un Injecteur-Mélangeur-Accélérateur (IMA) dans lequel le flux et le flux f ^t sont destinés à être injectés/mélangés/accélérés;
  2. ii. au moins un convertisseur du flux accéléré f ^c1/t en énergie mécanique;
  3. iii. éventuellement au moins un transformateur de cette énergie mécanique en énergie électrique et/ou en énergie frigorifique;
  4. iv. au moins un séparateur de FT et de FC;
     • la boucle de circulation de FT comportant au moins un échangeur thermique entre FT (étape V, voire VI) et FF, au moins un condenseur de FT et au moins une pompe de mise en circulation de FT dans cette boucle;
     • la boucle de circulation de FC comportant un échangeur thermique entre FC (étape II) et FF et au moins une pompe de mise en circulation de FC dans cette boucle.

In another of its aspects, the present invention as formulated by claim 8 relates to a simple and effective device, in

• particular for the implementation of the method according to the invention, characterized in that it comprises at least one FT circulation loop and at least one FC circulation loop,
• these two loops having in common:
  1. i. at least one Injector-Mixer-Accelerator (IMA) in which the flow and the flow f ^t are intended to be injected/mixed/accelerated;
  2. ii. at least one converter of the accelerated flux f ^c1/t into mechanical energy;
  3. iii. possibly at least one transformer of this mechanical energy into electrical energy and/or into cooling energy;
  4. iv. at least one FT and FC splitter;
     • the FT circulation loop comprising at least one heat exchanger between FT (stage V, even VI) and FF, at least one FT condenser and at least one pump for circulating FT in this loop;
     • the FC circulation loop comprising a heat exchanger between FC (stage II) and FF and at least one FC circulation pump in this loop.

Preferably, the IMA comprises at least one mixer with nozzles of the fragmented stream f ^c0 and of the stream f ^t in the form of vapor.

To further increase the kinetic energy of the flow producing mechanical movement, the IMA advantageously comprises at least one acceleration nozzle connected to the outlet of the mixer or mixers.

Preferably, the converter of the accelerated flux f ^c1/t into mechanical energy is constituted by at least one turbine, preferably an action turbine.

• → le transformateur de l'énergie mécanique en énergie électrique, est constitué par au moins un alternateur et/ou au moins une génératrice,
• → ou le transformateur de l'énergie mécanique en énergie frigorifique est constitué par au moins une machine frigorifique comprenant au moins un compresseur comportant au moins un arbre susceptible d'être entraîné en rotation par une source d'énergie mécanique.

On an interesting feature of the invention:

• → the transformer of mechanical energy into electrical energy, consists of at least one alternator and/or at least one generator,
• → or the transformer of mechanical energy into cooling energy consists of at least one refrigerating machine comprising at least one compressor comprising at least one shaft capable of being rotated by a source of mechanical energy.

For example, this transformer of mechanical energy into refrigerating energy consists of at least one direct drive of the shaft of the compressor of the refrigerating machine.

• au moins un fragmenteur du flux f^c0 sous forme de gouttelettes, ledit fragmenteur comportant au moins une buse, préférentiellement plusieurs afin de minimiser les pertes de charge sur le flux f^c0;
• au moins une chambre de mélange du flux f^c0 après fragmentation et du flux f^t sous forme d'eau et/ou de vapeur, cette chambre de mélange convergeant dans le sens des flux FT et FC;
• au moins un conduit d'admission de FT dans la chambre de mélange ;
• au moins une canalisation d'admission de FC dans la chambre de mélange;

• la chambre de mélange comportant une sortie disposée à son point de convergence, cette sortie débouchant dans au moins un conduit d'accélération;
• le conduit d'admission de FT comprenant un segment interne et axial par rapport à la chambre de mélange, ce segment interne et axial étant muni d'au moins une buse terminale d'éjection de FT, qui comporte un orifice de sortie de FT disposé au voisinage de la partie d'extrémité de plus petite dimension de la chambre de mélange convergente ;
• la canalisation d'admission de FC communiquant avec une pluralité de buses d'éjection de FC qui sont réparties sur le pourtour du segment interne et axial d'admission de FT, et qui comporte des orifices de sortie de FC en amont de l'orifice de sortie de FT;
• le segment interne et axial du conduit d'admission de FT étant de préférence équipé d'un organe d'accélération, avantageusement formé par un venturi.

In one embodiment, the mixer is a nozzle mixer which includes:

• at least one splitter of the flow f ^c0 in the form of droplets, said splitter comprising at least one nozzle, preferably several in order to minimize the pressure drops on the flow f ^c0 ;
• at least one chamber for mixing the flow f ^c0 after fragmentation and the flow f ^t in the form of water and/or steam, this mixing chamber converging in the direction of the flows FT and FC;
• at least one FT inlet conduit into the mixing chamber;
• at least one FC inlet line into the mixing chamber;

• the mixing chamber comprising an outlet disposed at its point of convergence, this outlet opening into at least one acceleration conduit;
• the FT inlet duct comprising an internal and axial segment with respect to the mixing chamber, this internal and axial segment being provided with at least one end FT ejection nozzle, which comprises an FT outlet orifice disposed in the vicinity of the end part of the smallest dimension of the convergent mixing chamber;
• the FC inlet pipe communicating with a plurality of FC ejection nozzles which are distributed around the periphery of the internal and axial segment of the FT inlet, and which comprises FC outlet ports upstream of the port FT output;
• the internal and axial segment of the FT inlet duct preferably being equipped with an acceleration member, advantageously formed by a venturi.

Definitions

Throughout this presentation, any singular designates either a singular or a plural.

• "fluide" : corps liquide et/ou gazeux
• "fluide fatal FF" : fluide porteur de la chaleur fatale destinée à être convertie en énergie mécanique
• "fluide thermodynamique FT" : fluide au moins en partie vaporisable au moyen des calories de l'énergie thermique à convertir et provenant du fluide fatal FF
• "vapeur " : état gazeux du fluide
• "fluide caloporteur FC" : fluide liquide apte à absorber les calories de l'énergie thermique à convertir et provenant du fluide fatal FF, sans passer entièrement à l'état gazeux ;
• "environ" ou "sensiblement" signifie à plus ou moins 10 % près, voire plus ou moins 5% près, rapporté à l'unité de mesure utilisée;
• "compris entre Z1 et Z2" signifie que l'une et/ou l'autre des bornes Z1, Z2 est incluse ou non dans l'intervalle [Z1, Z2] ;
• « non miscible à l'eau » s'entend dans les conditions de température et de pression qui sont celles du procédé selon l'invention.
• La «température d'apparition d'un vernissage » est la température à partir de laquelle on a un changement des caractéristiques de viscosité de l'huile, en particulier une augmentation marquée de la viscosité.

The definitions given below as examples may be used to interpret this presentation:

• “ fluid ”: liquid and/or gaseous body
• " fatal fluid FF ": fluid carrying the fatal heat intended to be converted into mechanical energy
• " thermodynamic fluid FT ": fluid at least partly vaporizable by means of the calories of the thermal energy to be converted and originating from the fatal fluid FF
• " steam ": gaseous state of the fluid
• “ heat transfer fluid FC ”: liquid fluid capable of absorbing the calories of the thermal energy to be converted and coming from the fatal fluid FF, without passing entirely into the gaseous state;
• " approximately " or "substantially" means to within plus or minus 10%, or even plus or minus 5%, relative to the unit of measurement used;
• “ included between Z1 and Z2” means that one and/or the other of the terminals Z1, Z2 is included or not in the interval [Z1, Z2];
• “ immiscible with water” means under the temperature and pressure conditions which are those of the process according to the invention.
• The " varnishing appearance temperature " is the temperature from which there is a change in the viscosity characteristics of the oil, in particular a marked increase in viscosity.

Detailed description of the invention

• La figure 1 est un schéma synoptique du système selon invention qui comprend le procédé avec ses modalités opératoires et le dispositif avec ses éléments constitutifs.
• La figure 2A est un schéma du système selon invention faisant apparaître les flux de fluide thermodynamique FT et de fluide caloporteur FC à différents endroits du dispositif et à différents moments du procédé.
• La figure 2B est un diagramme d'entropie de la température T du fluide thermodynamique FT en fonction de l'entropie S, correspondant au système de la figure 2A.
• La figure 3A est un schéma d'une variante double détente du système selon invention faisant apparaître les flux de fluide thermodynamique FT et de fluide caloporteur FC à différents endroits du dispositif et à différents moments du procédé.
• La figure 3B est un diagramme d'entropie de la température T du fluide thermodynamique FT en fonction de l'entropie S, correspondant au système de la figure 3A.
• La figure 4 est une vue en coupe de l'injecteur-mélangeur-accélérateur (IMA) selon un premier mode de réalisation.
• La figure 5 est une vue schématique en coupe partielle de la turbine et de l'alternateur du dispositif montré sur les figures 1 & 2A.

This description is made with reference to the appended figures in which:

• There figure 1 is a block diagram of the system according to the invention which comprises the method with its operating methods and the device with its constituent elements.
• There figure 2A is a diagram of the system according to the invention showing the flows of thermodynamic fluid FT and of heat transfer fluid FC at different locations in the device and at different times during the process.
• There figure 2B is an entropy diagram of the temperature T of the thermodynamic fluid FT as a function of the entropy S, corresponding to the system of the figure 2A .
• There Figure 3A is a diagram of a double expansion variant of the system according to the invention showing the flows of thermodynamic fluid FT and of heat transfer fluid FC at different locations of the device and at different times of the process.
• There Figure 3B is an entropy diagram of the temperature T of the thermodynamic fluid FT as a function of the entropy S, corresponding to the system of the Figure 3A .
• There figure 4 is a sectional view of the injector-mixer-accelerator (IMA) according to a first embodiment.
• There figure 5 is a partial sectional schematic view of the turbine and alternator of the device shown in the figure 1 & 2A .

PROCESS Preferred mode of implementation of the method according to the invention

There figure 1 appended diagrammatically illustrates the principle and the means of the system according to the invention for converting thermal energy into mechanical then electrical energy.

Block -1- symbolizes a fatal heat source contained in a fatal fluid (FF). It may be for example a smoke-emitting industrial process (FF).

FF (temperature T°) is conveyed by a pipe 2° through a first exchanger 3i, then by a pipe 2 ¹ (FF at a temperature T ¹ ), through a ^2nd exchanger 4i in series with the 3i exchanger. Coming out of the exchanger 4i, FF (temperature T ² ) is brought via a pipe 2 ² , into a flue gas treatment installation FF, symbolized by block 5. This treatment is, for example, a filtration carried out by means of a bag filter.

FF stripped of at least some of the solid elements, is evacuated through line ²³ to a chimney 6 which releases FF into the ambient air.

The device symbolized on the figure 1 further comprises an injector-mixer-accelerator (IMA) 10ii producing a mixed and accelerated double-phase flow f ^c1/t , a converter 11iii of the kinetic energy of the mixed and accelerated double-phase flow f ^c1/t , into mechanical energy, and a 12iv transformer of this mechanical energy into electrical energy. The converter 11iii is for example a Pelton-type action turbine and the transformer 12iv, an electric generator.

According to the invention, a fluid circulation loop FC and a fluid circulation loop FT are provided.

• l'échangeur thermique 3i;
• une canalisation 31 d'alimentation de FC dans l'échangeur 3i;
• un serpentin 32, siège du transfert de calories de FF vers FC ( à titre d'alternative au serpentin, il est possible de mettre en oeuvre un échangeur fonctionnant selon une autre technologie, par exemple : tube de fumée, plaques...) ;
• une canalisation 33 de transfert de FC de l'échangeur 3i vers l'IMA 10ii;
• l'IMA 10ii;
• la turbine 11iii;
• la génératrice 12iv;
• un séparateur de FC et de FT comprenant une capacité 13v et disposé en sortie de turbine 11iii
• une canalisation 34 de récupération/recyclage de FC, connectée à la capacité de séparation 13v;
• une pompe 35 de mise en circulation de FC,
  cette pompe 35 étant reliée, d'une part, à la capacité de séparation13v par la canalisation 34, et, d'autre part, à l'échangeur 3i, par la canalisation 31.

The FC loop includes:

• the heat exchanger 3i;
• a line 31 for supplying FC to the exchanger 3i;
• a coil 32, seat of the transfer of calories from FF to FC (as an alternative to the coil, it is possible to implement an exchanger operating according to another technology, for example: smoke tube, plates, etc.);
• a pipe 33 for transferring FC from the exchanger 3i to the IMA 10ii;
• IMA 10ii;
• turbine 11iii;
• the 12iv generator;
• an FC and FT separator comprising a capacitor 13v and arranged at the outlet of the turbine 11iii
• a FC recovery/recycling pipe 34, connected to the separation capacitor 13v;
• a pump 35 for circulating FC,
  this pump 35 being connected, on the one hand, to the separation capacity 13v by the pipe 34, and, on the other hand, to the exchanger 3i, by the pipe 31.

• l'échangeur thermique 4i;
• une canalisation 41 d'alimentation de FT dans l'échangeur 4i;
• un serpentin 42, siège du transfert de calories de FF vers FC ( à titre d'alternative au serpentin, il est possible de mettre en oeuvre un échangeur fonctionnant selon une autre technologie, par exemple : tube de fumée, plaques...) ;
• siège du transfert de calories de FF vers FT ;
• une canalisation 43 de transfert de FT de l'échangeur 4i vers l'IMA 10ii;
• l'IMA 10ii;
• la turbine 11iii;
• la génératrice 12iv;
• un séparateur 13v de FC et de FT, en sortie de turbine 11iii
• une canalisation 44 de récupération/recyclage de FT vapeur, connectée au séparateur 13v;
• un condenseur 45 de FT;
• une canalisation 46 de recueil de FT liquide à la sortie du condensateur 45;
• une pompe 47 de mise en circulation de FT,
  cette pompe 47 étant reliée, d'une part, au condenseur 45 par la canalisation 46, et, d'autre part, à l'échangeur 4i, par la canalisation 41.

The FT loop includes:

• the heat exchanger 4i;
• a pipe 41 for supplying FT in the exchanger 4i;
• a coil 42, seat of the transfer of calories from FF to FC (as an alternative to the coil, it is possible to implement an exchanger operating according to another technology, for example: smoke tube, plates, etc.);
• location of calorie transfer from FF to FT;
• a pipe 43 for transferring FT from the exchanger 4i to the IMA 10ii;
• IMA 10ii;
• turbine 11iii;
• the 12iv generator;
• a 13v splitter of FC and FT, at the turbine outlet 11iii
• a line 44 for recovering/recycling FT steam, connected to the separator 13v;
• an FT condenser 45;
• a pipe 46 for collecting liquid FT at the outlet of capacitor 45;
• a pump 47 for circulating FT,
  this pump 47 being connected, on the one hand, to the condenser 45 by the pipe 46, and, on the other hand, to the exchanger 4i, by the pipe 41.

FT is advantageously selected from the group comprising: water, glycerol, and mixtures thereof. FC is advantageously selected from vegetable or mineral oils which are immiscible with water, for example castor oil and/or olive oil.

The fatal fluid FF consists eg of fumes.

In the figure 2A &2B, FT is, for example, water identified by the references e1 to e6, FC is, for example, castor oil, identified by the references h1 to h3, and the fumes FF are identified by the references f1 to f3.

As shown on the figure 2A &2B, in the loop FC, a liquid flow f ^c0 of oil h1, at the temperature Th1, for example between 200 and 350° C., and at a pressure Ph1, travels in the pipe 34, thanks to the oil pump 35 for circulating f ^c0 , then a liquid flow f ^c0 of oil h2 at a pressure Ph2 greater than Ph1, reaches the oil inlet of the heat exchanger 3i fumes f1 / oil h2, through line 31.

The fumes f1 enter the exchanger via another inlet, and preferably countercurrent to the liquid flow f ^c0 .

The operating pressure Pf ^c0 (in bars) of the flow f ^c0 before the spraying in step III and after the compression of the flow f ^c0 of FC in step XII, is for example between 10 and 20 bars.

The flow f ^c0 of oil h3 heated in step (II) is collected at the outlet of exchanger 3i via line 33, at the temperature Th3 > Th1 & Th2, for example between 200 and 350° C., then enters in IMA 10ii. The speed V of the flow f ^c0 is, for example, between 10 and 20 m/s.

The IMA 10ii includes a fragmenter which transforms this liquid flow f ^c0 of h3 oil into a mist of h3 droplets. The size of these droplets is for example between 200 and 400 μm.

As shown on the figure 2A &2B, in the loop FT, a liquid flow f ^t0 of water e1, at a temperature lower than that of condensation Te _cond , travels in the pipe 46, thanks to the water pump 47 for circulating f ^t0 , then a liquid flow f ^t0 of water e2, at a temperature Te2, for example between 40 and 80°C, lower than Te _cond , reaches the water inlet of the heat exchanger 4i fumes f2 / water e2, through the line 41.

The fumes f2 coming from the heat exchanger 3i, fumes f1 / oil h2, enter the exchanger 4i via another inlet, and preferably countercurrent to the liquid flow f ^t0 .

The operating pressure Pf '(in bars) of the flow f ^t before the spraying of stage III and after the compression of the flow f ^t00 of FC in stage XIV is for example identical to Pf ^c0 and between 10 and 20 bars.

The flow f ^t of water e3 heated in step (V) and at least partly consisting of steam, is collected at the outlet of the exchanger 4i through the pipe 43, at the temperature Te3> Te1 & Te2, for example included between 180 and 250°C, then enters the IMA 10ii.

Te3 advantageously corresponds to the evaporation temperature Te _vap of the FT, in this case of water. The speed V of the vapor flow f ^t is, for example, between 60 and 100 m/s.

The optional step (VI) of heating the flow f ^t of water e3 flow f ^t , to vaporize it so that its vapor content is greater than or equal to 0.9; preferably at 0.95, is achieved by suitable sizing of the exchanger 4i.

• de l'étape (III) de pulvérisation du flux f ^c0 chauffé dans l'étape (II) pour générer un flux f ^c1 fragmenté de gouttelettes de fluide FC, en l'occurrence huile;
• de l'étape (VII) d'injection du flux f^t dans au moins une enceinte recevant également le flux f ^c1 de fluide FC, pour former un flux mélangé biphasique f ^c1/t e3m;
• de l'étape (VIII) d'accélération et de détente du flux f ^c1/t mélangé biphasique e3m.

The part common to the FT and FC loops which includes the elements of the IMA device 10ii, turbine 11iii, alternator 12iv and separator 13v, is then the seat:

• step (III) of spraying the stream f ^c0 heated in step (II) to generate a stream f ^c1 fragmented with droplets of fluid FC, in this case oil;
• of the step (VII) of injecting the flow f ^t into at least one enclosure also receiving the flow f ^c1 of fluid FC, to form a two-phase mixed flow f ^c1/t e3m;
• of step (VIII) of acceleration and relaxation of the biphasic mixed flow f ^c1/t e3m.

This acceleration increases the speed of the flow f ^c1 mixed with the flow f ^t , from 10 to 20 m/s, to a speed Vf ^c1/t greater than or equal to 100 m/s, for example between 120 and 140 m/s. This biphasic mixed flux f ^c1/t e3m becomes the accelerated biphasic mixed flux f ^c1/t e4.

During step (VII) to form a two-phase mixed flow f ^c1/t , the mass flow rates of the fluids FT and FC are adjusted so that the ratio Rd= mass flow rate of FT/Σ mass flow rates of FT & FC = 1 to 20%, for example 10%.

There figure 2B which represents the cycle described by the flow f ^t of vapor e3 between the hot source and the cold source in space T temperature and S entropy, shows that the expansion of stage (VII), is an isothermal expansion up to the mixture of the vapor flow f ^t and the fragmented flow f ^c1 , which induces quasi-isothermal expansion down to the flow f ^c1/t e3m.

This corresponds to step (VIII) of acceleration and expansion of the biphasic mixed flow f ^c1/t .

This supposes to ensure by the dimensioning of the exchangers 3i & 4i that Th3 is > to Te3.

The acceleration undergone by the flow f ^{c1 / t} e3m in the IMA 10ii produces an accelerated flow f ^{c1 / t} e4, which is projected on the blades of the turbine 11iii, for example of the Pelton 9 type, useful as a converter of the kinetic energy into mechanical rotational energy transmitted to the alternator 12iv which produces electrical energy, all this within the framework of step (IX).

Before the separation of step (X), the flow f ^c1/t e4 which has become e5 and released from a large part of its kinetic energy, is characterized by a pressure Pf ^c1/t approximately equal to or equal to atmospheric pressure.

After the separation of step (X), the flow f ^c1/t e5 is divided into a flow f ^t100 e6 and a flow f ^c0 h1. f ^c1/t and f ^t100 are recovered separately according to step (XI).

There figure 2B shows that the temperatures Te3m, Te4, Te4, Te5 and Te6 are equal to each other and are greater than the temperature Te _vap = Te3.

In step (XII), the flow rate is compressed and increased by f ^c0 .

The flow f ^t00 of water vapor e6 sees its temperature drop to reach the temperature Te1 of the flow f ^t0 at least partly of liquid water e1, during the condensation step according to step (XIII).

In step (XIV), the circulation speed is compressed and increased by f ^t0 .

Another variant of this preferred mode of implementation of the method according to the invention

According to an interesting possibility of the invention, it is ensured that the expansion of the flow f ^t in the enclosure also receiving the flow f ^c1 of fluid mist FC, generates a horn effect caused by a driving flow, namely the flow f ^t of FT, on an aspirated flow, namely the flow f ^c1 of FC.

This horn effect is determined by the configuration of the IMA 10ii mixing chamber.

Examples of embodiments of such a configuration are given below.

" Double expansion " variant of this preferred mode of implementation of the process according to the invention

This variant involves performing a step (VIII°) of pre-acceleration of the flow f ^t by expansion, preferably polytropic, of the flow f ^t .

There Figure 3A shows the diagram of the system according to this "double expansion" variant.

This corresponds to the diagram of the system according to the preferred embodiment shown in figure 2A , with the difference that the flow f ^t of steam e3 is introduced, via the pipe 43.1 connected to the outlet of the exchanger 4i, into an accelerator 14 of steam alone, in which this flow f 'is subjected to an expansion, preferably polytropic, which causes the temperature of Tevap = Te3 to fall, for example between 210 and 230°C, down to a temperature Te3i > Tevap = Te3 for example between 180 and 205°C. (See Figure 3B ).

The flow f ^t of water vapor e3i is then admitted, via the conduit 43.2, into the IMA 10ii.

The rest of the system according to this "double expansion" variant corresponds to the description given for the system according to the preferred mode of implementation of the method according to the invention.

DEVICE

In another of its aspects, the present invention relates to a device in particular for implementing the method according to the invention. This device includes:

3i heat exchanger

This is, for example, a flue gas/tube oil exchanger (against the current).

4i heat exchanger

This is, for example, a flue gas/water plate exchanger (against the current).

Steam Accelerator 14 only

This is, for example, an expansion nozzle whose profile is optimized to accelerate the speed of the flow of FT vapor.

IMA 10ii

Preferably, the 10M mixer(s) included in the IMA 10ii can be a mixer(s) in which the splitter(s) is a nozzle splitter and / or any other device known per se comprising a suitable fragmenter.

Preferably, the accelerator(s) 10A included in the IMA 10ii can be one or more acceleration nozzle(s) sized to be sonic at the throat (Fluid speed = speed of sound in the middle).

Embodiment with a nozzle mixer

• au moins une chambre 50 de mélange du flux sous forme de brouillard et du flux f ^t sous forme de vapeur ou de mélange vapeur/eau, cette chambre de mélange 50 convergeant dans le sens des flux f^t et f^c1;
• au moins un conduit 51 d'admission du flux f^t de FT dans la chambre 50 de mélange ;
• au moins une canalisation 52 d'admission de FC dans la chambre 50 de mélange;

As shown on the figure 4 , the nozzle mixer preferably comprises:

• at least one chamber 50 for mixing the flow in the form of mist and the flow f ^t in the form of steam or a steam/water mixture, this mixing chamber 50 converging in the direction of the flows f ^t and f ^c1 ;
• at least one duct 51 for admitting the flow f ^t of FT into the mixing chamber 50;
• at least one FC inlet pipe 52 in the mixing chamber 50;

The mixing chamber 50 has in this embodiment the general shape of an ogive, provided with an upstream wall 53, a longitudinal wall 54, and a downstream end portion 55 of convergence. The upstream wall 53 is connected to the conduit 51 for admission of FT inside the mixing chamber 50. A nozzle holder 56 connects the inlet duct 51 to a terminal nozzle 57 for ejecting the flow f ^t of vapor e3i into the enclosure 58 of the mixing chamber 50. The nozzle holder 56 comprises in its end part a nozzle 57 making it possible to carry out step (VIII) of acceleration and expansion of the flow f ^t , preferably quasi-isothermal or by default polytropic, of the flow f ^t of vapor e3 ( Figure 3A ) so as to obtain the flow f ^t of vapor e3i ejected.

The nozzle holder 56 is an internal and axial segment with respect to the mixing chamber. The terminal FT ejection nozzle 57 comprises an outlet orifice 57 ^s for the flow f ^t of vapor e3, arranged in the vicinity of the end part of the smallest dimension of the converging ogival chamber 50 .

The pipe 52 for inlet of the flow f ^c0 of FC into the mixing chamber 50 extends in a direction orthogonal with respect to the pipe 51 for the inlet of the flow f ^t of FT. This pipe 52 opens into a circular pre-chamber 60 located in the upstream part of the chamber 50 in the form of an ogive. This pre-chamber 60 distributes the flow f ^c0 of FC to a set of peripheral nozzles 61,62 distributed evenly around the nozzle holder 56, according to 2 levels, a central upstream level: nozzles 62 and a peripheral downstream level: nozzles 61. These nozzles 61,62 whose FC outlet orifices are upstream of the outlet orifice 57 ^s of the flow f ^t of FT, produce the mist of FC droplets (flow f ^c1 ) in the enclosure 58 of the chamber 50 mix.

The downstream end part 55 of convergence of the mixing chamber 50 is secured to the longitudinal wall 54 of this mixing chamber 50, by means of an upstream system of flanges and bolts designated by the general reference 63 on the figure 4 . A circular sealing gasket 64 is arranged between this downstream end part 55 and the longitudinal wall 54. Another downstream system 66 of flanges and bolts allows the attachment of the downstream end part 55 of the ogival chamber 50 to a conduit of acceleration 67. The latter consists of a nozzle (of which only the upstream part and represented on the figure 4 ), collects the biphasic mixed flow f ^c1/t (referenced e3m on the Figure 3A ) to make it undergo an acceleration.

The nozzles 61 and 62, which are for example and in this case those which comprise an end portion in the form of a helical (“corkscrew”).

The nozzle holder 56 with an upstream constriction 59, as well as the acceleration nozzle 67 are also parts known per se and suitable for the performance of the vapor or biphasic vapor/oil fluid acceleration function.

On a remarkable characteristic of the invention, the end of the outlet orifice 57 ^s of the terminal ejection nozzle 57 is placed at a distance d from the terminal part upstream of the inlet of the acceleration duct 67 of diameter D, such that: D≤d≤3D, preferably 1.5D≤d≤2.5D.

On another remarkable characteristic of the invention, the converging ogival structure of the mixing chamber 50, the relative positioning of the nozzle 57 downstream of the nozzles 61/62 makes it possible to generate a horn effect by which the flow f * of FT is a motive fluid which entrains the aspirated fluid constituted by the mist of fluid droplets FC (oil) flux f ^c1 .

This horn effect makes it possible to reduce the pressure at the outlet of the pump 35 of the fluid FC and therefore to reduce the power consumed.

Kinetic energy converter / mechanical energy 11ii i

This is for example a Pelton-type turbine, such as that described in the patent application PCT WO2012/089940A2 , in particular in Figures 3 and 4 and in the corresponding parts of the description.

This example of kinetic energy converter 11iii is described again below with reference to the figure 5 .

The kinetic energy converter 11iii comprises a heat-insulated enclosure 150 formed of two domed half-shells 152 of elliptical shape advantageously welded to two flanges 154. The welding of the two half-shells 152 forms a sealed enclosure 150 of substantially vertical axis B and perpendicular to the axis A of the injector 151. The bottom of the enclosure 150 forms, for example, the heat transfer fluid reservoir FC (oil) where the latter is collected after it has passed through the converter 11iii, as will be described later. .

A tank 155 is arranged inside the enclosure 150. This tank 155 is formed of a bottom 156 of substantially frustoconical or funnel-shaped shape and a wall 157 of substantially cylindrical shape extending from bottom 156, bottom 156 and wall 157 extending along axis B. A cylindrical action wheel 158 is rotatably mounted on tank 155 via a shaft 159 extending along axis B substantially vertical. The action wheel 158 is placed facing the injector 20 so that the jet injected by the latter drives the action wheel 158 and the shaft 159 in rotation so as to transform the axial kinetic energy of the jet into energy. kinetics of rotation of the shaft 159. The action wheel 158 is arranged in the enclosure 150.

The impeller 158 includes a plurality of blades 160 extending substantially radially and having a concave shape. The concavity 161 of the blades 160 is turned towards the injector 151 so that the injected jet coming from the injector reaches said concavities 161 and causes the rotation of the wheel 158. The concavity of the blades 160 has an asymmetrical shape with respect to a axis C passing through the bottom 162 of the concavities and substantially perpendicular to these concavities, that is to say substantially parallel to the axis A located above the axis C. This asymmetry determines for each blade 160 an upper part 163 extending above the C axis and a lower part 164 extending below the C axis. The upper part 163 and the lower part 164 have radii of curvature and different lengths. In particular, the radius of curvature of the lower part 164 is greater than the radius of curvature of the upper part 163, while the length of the lower part 164 is greater than the length of the upper part 163.

The injector 151 is arranged to inject the jet on the upper part 163 of the blades 160. The position of the injection of the jet on the blades 160 as well as the particular shape of the latter make it possible to lengthen the path of the jet in the blades 160 and to improve the stratification of this jet at the outlet of the blades, which allows the subsequent separation of the heat transfer fluid and the high temperature gas. The exit angle of the jet of the blades 160, that is to say the angle formed between the tangent at the end of the lower part of the blade and the horizontal axis C, is substantially between 8° and 12° so that the jet at the vane outlet 160 has a greater kinetic energy than in a conventional Pelton turbine where the outlet angle of the vanes is substantially between 4° and 8°. This increase in kinetic energy makes it possible to improve the separation of the heat transfer fluid and the gas at high temperature.

Separator13v = deflector165

At the blade 160 outlet, the jet enters a deflector 165 extending under the blades 160 and arranged to redirect the fluid received towards the wall 157 of the tank 155. The deflector 165 makes it possible to stratify the mixture of heat transfer fluid and high temperature gas, as shown in the figure 4 of WO2012/089940A2 . In particular the deflector 165, more particularly represented on the picture 3 of WO2012/089940A2 , has a shape arranged to recover the mixture leaving the wheel 158 in a substantially vertical direction and to continuously redirect this mixture in a substantially horizontal direction, as shown in the figure 4 of WO2012/089940A2 , so that it leaves the deflector 165 tangentially to the wall 157 of the tank 155, that is to say that the mixture leaves the deflector 165 along the wall 157 of the tank 155. At this Indeed, the deflector 165 comprises at least one inlet opening 166 for the mixture of heat transfer fluid and high temperature gas at the outlet of the action wheel 158, said opening extending in a plane substantially perpendicular to the axis B of the impeller 158, that is to say a substantially horizontal plane, and an outlet opening 167 for the mixture, said opening extending in the vicinity of the wall 157 of the tank 155 and in a substantially vertical plane. The inlet opening 166 and the outlet opening 167 are connected to each other by an envelope 168 having a curved shape, as shown in the picture 3 of WO2012/089940A2 . According to the particular embodiment shown in the picture 3 of WO2012/089940A2 , internal walls extend inside the casing 168 substantially parallel thereto so as to define channels for circulation of the mixture in the casing and to separate several inlet openings and a corresponding number of exit openings.

The separation of the heat transfer fluid and the high temperature gas begins in the blades 160 by the centrifugation of the mixture due to the shape of the blades 160. Passing through the deflector 165, the rest of the mixture is stratified and passes continuously from a flow along the exit direction of the impeller 158 to a flow tangential to the wall 157 of the tank 155, as represented on the figure 4 of WO2012/089940A2 . This tangential flow causes a centrifugation of the mixture, due to the cylindrical shape of the wall 157, which makes it possible to complete the separation of the high temperature gas and the heat transfer fluid by cyclone effect. Thus, the separation of the mixture is carried out optimally so that the heat transfer fluid and the high temperature gas are more than 98% separated. The fact of providing an action wheel 158 in rotation around a substantially vertical axis B makes it possible to create the cyclone effect on the wall of the tank, because it is possible to place a deflector 165 redirecting the mixture in an appropriate manner.

According to one embodiment, the energy converter comprises several injectors 151, for example six, as in a conventional Pelton turbine and an equal number of deflectors 165.

Once separated, the heat transfer fluid is drawn towards the bottom of the tank 155 by gravity, while the high temperature gas, formed by water vapor moves towards the top of the enclosure 150. The upper part of the enclosure 150 comprises means 169 for recovering the high temperature steam stream f ^t separated from the heat transfer fluid FC. The high temperature vapor flow f ^t leaves the enclosure by these recovery means 169 and circulates in the rest of the installation as will be described later.

The bottom 156 of the tank 155 comprises means 170 for recovering the heat transfer fluid, so that the latter passes into the reservoir 171 on leaving the tank 157. These recovery means 170 are for example formed by flow holes made in the bottom 156 of the tank 155 and communicating between the tank 155 and the bottom of the enclosure 150.

The heat transfer fluid recovered serves in particular to lubricate at least one plain thrust bearing 70 of the hydrodynamic type via which the shaft 159 of the action wheel 158 is rotatably mounted on the bottom 156 of the tank 155. Indeed, the plain thrust bearing 172 is immersed in the heat transfer fluid recovered by the recovery means 173. Such a bearing 172 makes it possible to ensure the rotation of the shaft 159 at high speed in a high temperature environment with a long service life, unlike conventional ball bearings. In addition, the installation of the bearing 172 inside the enclosure 150 makes it possible to have no sealing problem and to avoid coolant leaks which could be dangerous. According to the embodiment represented in FIG. 7, the converter 11iii comprises two plain thrust bearings 172. In the tank 171, a circulation pump 173 for heat transfer fluid FC (oil), for example of the volumetric type, is mounted on the shaft 159 via a homokinetic joint 174. This pump is connected to an outlet pipe 175 connecting the inside of the enclosure 150 to the outside and allowing the heat transfer fluid to circulate towards the rest of the installation 1. Thus, the circulation pump 72 is arranged to suck the heat transfer fluid FC from the reservoir 171 and to inject it into the outlet pipe 175. The circulation pump has no drive motor since its actuation is ensured by the rotation of the shaft 159 of the action wheel 158 driven by the jet injected by the injector 151.

Transformer mechanical energy into electrical energy: 12iv alternator

As shown on the figure 5 , the shaft 159 of the action wheel 158 comes out of the enclosure 151 via a piston 184 arranged to ensure sealing between the interior of the enclosure 151 and the exterior of the enclosure 151 , for example a Swedish piston. The shaft 159 rotates the rotor of the alternator 12iv, advantageously of the permanent magnet type. This alternator 12iv makes it possible to transform the kinetic energy of rotation of the shaft 159 into electrical energy. The 12iv alternator is cooled, at its air gap, by a fan 180 mounted on its rotor and by a water circulation pipe, forming the cooling yoke 181, which sheaths its stator. The water supplying the cooling cylinder head 181 comes from a water supply source and is brought to the cylinder head by a volumetric pump 182 actuated by the shaft 159 via a reducer 183. Thus the pump 108 is devoid of an actuating motor. Cooling cylinder head 181 serves to cool alternator 12iv and to preheat the water, as previously described.

Condenser 45

The flow f ^t of water vapor collected by the recovery means 169 provided in the enclosure 151 of the figure 5 is cooled by a condenser 45 to be transformed into a flow f ^t0 of liquid thermodynamic fluid FT (water) before being recycled.

This may be, for example, an air cooler type condenser or an exchanger whose secondary is supplied with water at a temperature below 60°C (river, canal, etc.).

Claims (10)

1. A method for converting thermal energy, preferably of waste heat, contained in

   a fluid (FF) which is at least partly gaseous, into mechanical energy, and, preferably into electrical energy and/or into cooling energy;

   said method using at least one thermodynamic fluid FT and at least one heat transfer fluid FC, wherein:

   I. a flow f ^c0 of an at least partly liquid fluid FC is implemented;

   II. thermal energy to be converted obtained from the fluid FF is transferred to the flow f ^c0;

   III. the flow f ^c0 heated in (II) is sprayed to generate a split flow f ^c1 of fluid FC;

   IV. in parallel, a flow f ^t0 of an at least partly liquid fluid FT is implemented;

   V. then thermal energy to be converted obtained from the fluid FF is transferred to the flow f ^t0 of fluid FT, to generate a flow f^t, the temperature of which is higher than that of the flow f^t0, the fluid FT of the flow f^t being:

   i. in liquid phase;

   ii. in liquid phase and in vapour phase;

   iii. in saturation vapour phase;

   iv. or in superheated vapour phase;

   VI. if necessary, the flow f^t is heated to vaporise it so that its vapour content is greater than or equal to 0.9; preferably 0.95;

   VII. the flow f^t is injected into at least one enclosure also receiving the flow f ^c1 of fluid FC, to form a two-phase mixed flow f ^c1/t, the ratio Rd of the mass flow rate of the fluid FT to the total mass flow rate of the fluid FC and of the fluid FT, being comprised between 1 and 20%, preferably between 3 and 18%, and more preferably still between 5 and 150;

   VIII. this flow f ^c1/t is then accelerated and expanded;

   IX. the kinetic energy of this accelerated flow f ^c1/t is converted into mechanical energy; the latter optionally being transformed into electrical energy and/or into cooling energy;

   X. on the one hand, the fluid FT and, on the other hand, the fluid FC are separated;

   XI. on the one hand, an at least partly gaseous flow f ^t00 of the fluid FT and, on the other hand, an at least partly liquid flow f ^c0 of the fluid FC are recovered;

   XII. the speed of circulation of the flow f ^c0 of FC is compressed and increased;

   XIII. the at least partly gaseous flow f ^t00 of the fluid FT is condensed into an at least partly liquid flow f ^t0 of the fluid FT;

   XIV. the speed of circulation of the flow f ^t0 of the fluid FT is compressed and increased;

   the method comprises the implementation of at least one fluid FT circulation loop and at least one fluid FC circulation loop;

   these two loops having in common:

   i. at least one Injector-Mixer-Accelerator (IMA) wherein the flow f ^c0 and the flow f ^t are intended to be injected/mixed/accelerated;

   ii. at least one converter of the accelerated flow f ^c1/t into mechanical energy;

   iii. optionally at least one transformer of this mechanical energy into electrical energy and/or into cooling energy;

   iv. at least one separator of the fluid FT and the fluid FC;

   - the fluid FT circulation loop including at least one heat exchanger between the fluid FT (step V, even VI) and the fluid FF, at least one condenser of the fluid FT and at least one pump for circulating the fluid FT in this loop;

   - the fluid FC circulation loop including a heat exchanger between the fluid FC (step II) and the fluid FF and at least one pump for circulating the fluid FC in this loop.
2. The method according to at least one of the preceding claims wherein during step VII, the injection of the flow f^t of the thermodynamic fluid FT into an injection enclosure of the IMA is done at a speed comprised between 40 and 300 m/s, preferably between 50 and 150 m/s and, even more preferably, between 60 and 100 m/s.
3. The method according to at least one of the preceding claims, wherein it is ensured that the expansion of the flow f^t in the enclosure of the IMA also receiving the split flow f^c1 of fluid FC, generates an effect caused by a motor flow namely the flow f ^t of the fluid FT, on a suctioned flow, namely the flow f^c1 of the fluid FC.
4. The method according to at least one of the preceding claims wherein before the step VIII, the flow f^t is subjected, during at least one step (VIII°) of pre-acceleration by expansion, which is preferably quasiisothermal, of the flow f^t, in at least one chamber of suitable profile, preferably in a duct; this step (VIII°) being advantageously implemented in the same chamber of adapted profile as that of step (VIII).
5. The method according to at least one of the preceding claims, wherein the fluid FT is an aqueous liquid, preferably selected from the group comprising -ideally consisting of- water, glycerol and mixtures thereof; and in that the fluid FC is selected from vegetable or mineral oils, preferably from oils which are immiscible with water and/or which have a varnishing appearance temperature greater than or equal to 200°C, preferably 300°C, and more preferably still from vegetable oils; the fluid FC being ideally selected from the group comprising -ideally composed of-: castor oil and/or olive oil.
6. The method according to at least one of the preceding claims wherein the fluid
   FF initially has a temperature greater than 200°C and preferably greater than 300°C, and/or is selected from gas fluids and, even more preferably, from the group comprising -ideally composed of-: hot air, water vapour, engine exhaust gases, fumes, in particular industrial fumes, and heat from dryers or among liquid fluids (for example as is the case in concentrating solar plants).
7. The method according to at least one of the preceding claims comprising at least one of the following features:

   C1. an operating pressure Pf ^c0 (in bars) of the flow f ^c0 before the spraying in step III and after the compression of the flow f ^c0 of the fluid FC in step XII, is such that -preferably in increasing order -: 3 ≤ Pf ^c0 ≤ 30; 5 ≤ Pf ^c0 ≤ 25; 10 ≤ Pf ^c0 ≤ 15

   C2. an operating pressure Pf ^t (in bars) of the flow f^t before the injection during step VII and after the compression of the flow f ^t00 of the fluid FC in step XIV, is such that -preferably in increasing order-: $$3⩽{\mathrm{Pf}}^{\mathrm{t}}⩽30;5⩽{\mathrm{Pf}}^{\mathrm{t}}⩽25;10⩽{\mathrm{Pf}}^{\mathrm{t}}⩽15$$

   

   C3. Pf ^c0 and Pf ^t are identical or different, preferably identical;

   C4. a pressure Pf ^c1/t of the flow f ^c1/t after the step IX of conversion of kinetic energy into mechanical energy, in bars and preferably in increasing order, is such:
   Pf ^c1/t ≤ 2; 0.3 ≤ Pf ^c1/t ≤ 1.5; equal or approximately equal to the atmospheric pressure.
8. A device for implementing the method, according to at least one of the preceding claims, which comprises at least one FT circulation loop (41 - 47) and at least one fluid FC circulation loop (31 - 34), of at least one fluid FT circulation loop (41 - 47) and at least one fluid FC circulation loop (31 - 34);
   these two loops having in common:

   i. at least one Injector-Mixer-Accelerator "IMA" (10ii) wherein the flow f ^c0 and the flow f ^t are intended to be injected/mixed/accelerated;

   ii. at least one converter (11iii) of the accelerated flow f ^c1/t into mechanical energy;

   iii. optionally at least one transformer (12iv) of this mechanical energy into electrical energy and/or into cooling energy;

   iv. at least one separator (13v) of the fluid FT and the fluid FC;

   - the fluid FT circulation loop (41 - 47) including at least one heat exchanger (4i) between the fluid FT (step V, even VI) and the fluid FF, at least one condenser (45) of the fluid FT and at least one pump (47) for circulating the fluid FT in this loop;

   - the fluid FC circulation loop including a heat exchanger (3) between the fluid FC (step II) and the fluid FF and at least one pump (35vi) for circulating the fluid FC in this loop.
9. The device according to claim 8, wherein the IMA (10ii) comprises at least one nozzle mixer (10M) of the split flow f^c0 and of the flow f^t in the form of vapour.
10. The device according to at least one of claims 8 or 9 wherein the nozzle mixer (10M) comprises:

    - at least one splitter of flow f^c0 in the form of droplets, said splitter including at least one nozzle, preferably several nozzles in order to minimise pressure drops on the flow
    f^c0;

    - at least one chamber (50) for mixing the flow f^c0 after splitting and the flow f^t in the form of water and/or vapour, this mixing chamber converging in the direction of the flow of the fluid FT and the fluid FC;

    - at least one conduit (51) for fluid FT intake in the mixing chamber

    - at least one pipe (52) for fluid FC intake in the mixing chamber where the mixing chamber (50) includes an outlet disposed at its point of convergence, this outlet opening into at least one acceleration conduit (67);

    where the fluid FT intake conduit (51) comprises an internal and axial segment with respect to the mixing chamber (50), this internal and axial segment being provided with at least one end nozzle for ejecting the fluid FT, which includes a fluid FT outlet orifice disposed in the vicinity of the end part of the smallest dimension of the convergent mixing chamber;

    where the fluid FC intake pipe communicates with a plurality of fluid FC ejection nozzles (61, 62) which are distributed around the periphery of the internal and axial fluid FT intake segment, and which includes fluid FC outlet orifices upstream of the fluid FT outlet orifice;

    the internal and axial segment of the fluid FT intake conduit being preferably equipped with an acceleration member, advantageously formed by a venturi.

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