WO2014199072A1

WO2014199072A1 - Device for converting the thermal energy contained in a hot fluid and a cold fluid into mechanical energy, and facility including such a device

Info

Publication number: WO2014199072A1
Application number: PCT/FR2014/051401
Authority: WO
Inventors: Claude FAVY
Original assignee: Storewatt
Priority date: 2013-06-11
Filing date: 2014-06-11
Publication date: 2014-12-18
Also published as: FR3006719B1; FR3006719A1

Abstract

The invention relates to a device for converting the thermal energy contained in a hot fluid from a hot source and a cold fluid from a cold source into mechanical energy, including a pressure-resistant chamber (1), the device also including, inside the chamber (1), at least: a manifold (50); an assembly (30) for generating and accelerating mist inside the chamber (1); condensation means (16); and means for discharging fluids from the chamber (1); the device being characterised in that the assembly (30) for generating and accelerating mist includes at least: a mist generator (6); and a nozzle (7) rotatably mounted about the axis of rotation (3) relative to the chamber (1).

Description

Device for converting the thermal energy contained in a hot fluid and a cold fluid into mechanical energy, and an installation comprising such a device

The present invention relates to a device for converting thermal energy into mechanical energy. It applies to the conversion of thermal energy between a hot source and a cold source with a small difference in temperature and more particularly to the thermal energy of the seas.

The conversion of thermal energy between a hot source at a moderate temperature and a cold source with a small difference in temperature into mechanical energy has long been an important issue.

Such configurations are particularly numerous and may be mentioned for example:

• low temperature geothermal energy (hot spring temperature from 60 ° C to 150 ° C);

• industrial heat discharges at low temperatures (hot spring temperature of 70 ° C to 500 ° C);

· The thermal energy of the seas (ETM), with a hot spring temperature of 20 ° C to 30 ° C, and a difference in temperature between the surface layers and the deep layers of the oceans which reaches close to 20 ° C in the inter-tropical zones.

Many devices for converting this thermal energy into mechanical energy have been proposed but the industrial applications are still few considering the following points:

• The very low temperature differences between hot and cold source imply a theoretical maximum conversion rate of thermal energy to very low mechanical energy (of the order of 7% for ΙΈΤΜ).

• The effectiveness of the proposed devices remains very limited, which reduces this conversion rate even further.

• As a result, the volumes of fluid to be treated are extremely important, requiring very large heat exchange devices.

The solutions proposed in the prior art can be divided as follows:

Solutions that use an organic Rankine cycle, that is to say, in that the hot fluid from the hot source transfers its heat to a working fluid through an exchanger to vaporize it, the working fluid relaxes to through a turbine by providing a mechanical work and is then condensed in a condenser by exchanging with the cold fluid of the cold source to be finally pressurized by a pump. This so-called closed cycle has the advantage of allowing the use of a working fluid having volumigable densities of high vapor at the temperatures considered and therefore of reasonable size turbines. However, it has major drawbacks including the enormous size of the heat exchangers between hot and cold sources and the working fluid that must be able to handle very high flow rates with a minimum temperature nip. The "biofouling" hazards (inlay of living organisms in the various equipment) of these Exchangers in the case of ΙΈΤΜ are very important and the need to use working fluids like ammonia also presents real dangers to the environment.

• Solutions in which the hot fluid (usually water) is vaporized partly through its own specific heat (this phenomenon is known as flash vaporization), its vapor relaxed in a turbine where it provides a job mechanical, the steam being subsequently condensed through the heat exchange (usually direct) with the fluid from the cold source (usually water). This so-called open cycle solution has the enormous advantage of avoiding oversized heat exchangers between two different fluids. However, it has major limitations especially in the case of ΙΈΤΜ. Indeed, in this case, the temperature of the hot source (approximately 28 ° C) corresponds to extremely low vapor pressures of the order of 3 hundredths of a bar. At this pressure, the density of the steam is very low and it is therefore necessary to pass through the turbine an extremely large volume flow which implies both very high rotor diameters and high peripheral speeds. The centrifugal forces on the elements of the turbine then become too important for powers from a few MW (Mega Watt). In addition the inertia of the turbine also becomes very important which can generate problems of coupling to the electrical network. This open cycle is therefore less and less considered for powers greater than a few MW.

• Solutions in which the hot water undergoes a flash vaporization, its vapor relaxed in a vertical divergent where it communicates part of its energy to liquid water so as to raise this water in the device by fighting against gravity. The energy is then recovered by simple hydraulic turbining of the liquid phase which has been raised. The proposed solutions include raising water:

1. In the form of bubbles, as described for example in US Pat. No. 3,967,449, in which steam bubbles are produced in the liquid phase so as to reduce the density of the assembly. This device has great difficulty in maintaining the pressure conditions necessary for the formation of bubbles in the liquid phase.

2. As a foam, as described for example in US 4,249,383, wherein a foam composed of steam, hot water and a foaming agent is formed and raised by steam. The need to use a foaming agent and the difficulty in maintaining the stability of the foam seem unacceptable.

3. in the form of drops, as described for example in US 4,441,321 in which microdroplets are raised by their own steam in a vertical enclosure. Although simple, this device has the disadvantage of requiring very large steam passage sections (given the very low density of the steam and its limited initial speed) associated with very large heights. For example, such a device of 4 MW for ΙΈΤΜ would be 20m in diameter for nearly 100m high. We imagine the difficulties of realization and operation and the cost of such a device. We can also mention the significant energy losses by collision of microdrops with the walls or between them given the very great vertical distance to travel. • Finally, we can mention the many devices using so-called diphasic turbines. Within this category, we can distinguish:

1. solutions in which the fluid is introduced in liquid form, expanded to form a vapor phase and a liquid phase, the two phases are then separated by means of a separator and each expanded in separate devices adapted to each phase. These solutions have a great complexity and poor efficiencies 2. the solutions in which the fluid is expanded through a nozzle, vaporizing partly at the outlet of the nozzle, the liquid and vapor assembly then relaxing through a suitable nozzle . Given the presence of a very large liquid phase, any relaxation in a turbine with changes in direction of the fluid is prohibited or damage to the blades quickly. It remains the solution of the single-stage reaction turbine. In this type of turbine, it is necessary to maintain good efficiency that the absolute velocity of the fluid at the outlet of expansion is as low as possible. However, the ejected fluid is more than 95% by mass in liquid form while the mass of the vapor part remains very low. However, it is the steam that transforms most of the available enthalpy into kinetic energy during relaxation. The two phases that are not mechanically coupled in the proposed devices will therefore have very different speeds at the output of the detent incompatible with a good efficiency of the turbine.

The device according to the invention makes it possible to provide an answer to these difficulties, in particular: it makes it possible to avoid the problems related to oversized heat exchangers of closed cycles;

it allows to treat very important hot fluid flows while maintaining a good efficiency

it allows to use only seawater through an open cycle in the case of ΙΈΤΜ; it makes it possible to maximize the mechanical coupling between the liquid phase and the vapor phase while permitting a speed of the liquid phase close to the peripheral speed and thus to obtain absolute speeds of the very low liquid phase at the expansion output associated with absolute speeds of the vapor phase limited, allowing excellent efficiency of the device;

it limits the length of travel of the liquid phase reducing the risk of collision between liquid elements or with the walls;

it makes it possible to limit the speed of rotation of the rotating part, its inertia as well as the centrifugal forces acting on the various components while maintaining a good efficiency;

its construction is simple, based on inexpensive materials and without significant precision constraints;

it does not use any fluid presenting risks for the environment especially in the case where the fluid of the hot and cold springs is water. it allows to use only seawater as working fluid in the case of ΙΈΤΜ;

In the text that follows, the terms droplets or microdroplets designate drops of diameter from about ten microns to a few millimeters.

The expression "mist of droplets" refers to a cluster of droplets (several millions or billions per cubic meter) dispersed in the vapor generated by their own partial evaporation.

According to a first aspect, the device according to the invention relates to a device for converting the thermal energy contained in a hot fluid from a hot source into a mechanical energy and a cold fluid from a cold source, the hot fluid. being at a temperature higher than that of the cold fluid. The device comprises at least one external pressure-resistant enclosure defining an internal medium, the device further comprising, inside the at least one enclosure, at least:

a distributor in rotation or not around an axis of rotation in the enclosure, comprising an inlet intended to be in fluid connection with the hot source outside the enclosure;

a generator and fog accelerator assembly inside the enclosure, the fog comprising a mixture of droplets and steam, the generator and fog accelerator assembly being supplied with hot fluid by the distributor,

- Condensation means, adapted to be in fluid connection with the cold source, for condensation by cooling by means of the fluid of the cold source of the steam produced inside the enclosure;

means for evacuating fluids from the enclosure.

The generator and fog accelerator assembly comprises at least:

- A fog generator, in fluid connection with the distributor for generating a mist of hot fluid droplets animated with an initial speed and dispersed in the vapor formed by their own partial evaporation;

a nozzle rotatably mounted about the axis of rotation relative to the chamber for relaxing and guiding inside the chamber the mist of droplets and vapor generated by the fog generator, the at least one nozzle extending at least partially in a direction transverse to the axis of rotation so that the fog flow causes by reaction the rotation of the nozzle around the axis of rotation.

According to a first embodiment, the at least one distributor and the at least one mist generator are rigidly attached to the at least one nozzle, in rotation about the axis of rotation, the at least one nozzle being in the extension of the at least one fog generator, the at least one fog generator being oriented with respect to the axis of rotation so that the relative initial velocity with respect to the fog generator of the droplets generated by the at least one fog generator comprises a cross-cutting component the axis of rotation which is substantially opposite to the orthogonal component of the speed of rotation of the at least one nozzle around the axis of rotation.

According to a second embodiment, the at least one distributor is fixed relative to the enclosure, the initial speed of the droplets generated by the at least one fog generator having a centrifugal radial component and the at least one nozzle rotating around the axis of rotation is positioned at the periphery of the at least one fog generator.

According to a third embodiment, the at least one distributor is fixed in the chamber, the initial speed of the droplets generated by the at least one mist generator having a centripetal radial component and the at least one nozzle rotating about the axis. rotation is positioned closer to the axis of rotation than the fog generator (s).

According to a fourth embodiment, the distributor or distributors are fixed in the enclosure, the initial speed of the droplets generated by the at least one fog generator having an axial component parallel to the axis of rotation and the at least one nozzle in rotation about the axis being positioned axially offset from the at least one fog generator.

According to an exemplary embodiment, the axis of rotation is vertical.

The at least one mist generator may comprise at least one plate pierced with a multitude of holes of a shape, size and spacing specially optimized to produce mist of droplets.

In addition, the at least one fog generator may comprise at least a multitude of two-phase nozzles, each two-phase nozzle comprising at least one convergent, a neck and a divergent, the two-phase nozzles being contiguous to each other.

According to an exemplary embodiment, the fluids of the hot source and the cold source are water. For example, the hot spring is surface water and the cold source is water from the depths of an ocean.

The device may further comprise a generator for transforming the mechanical energy generated by the rotation of the at least one nozzle into electrical energy. The generator may for example be an electric generator coupled directly or via a reduction box to the at least one nozzle. In a variant, the generator may comprise one or more hydroelectric units making it possible to transform all or part of the pressure energy of the hot fluid in the distributor into electrical energy.

According to one embodiment, the condensation means use condensation by direct contact between the vapor to be condensed and the fluid of the cold source. Alternatively, the condensing means use the condensation at least partly without direct contact between the steam to be condensed and the fluid from the cold source. According to this variant, the device may then comprise at least one recuperator allowing the recovery of the fresh water coming from the condensation of the steam without direct contact between the steam to be condensed and the fluid of the cold source.

In addition, the device may comprise a rolling device for supporting all or part of the weight of the elements. The at least one fog generator may be provided with a cleaning device to eliminate the biofouling.

According to an exemplary embodiment, the device further comprises flotation means. According to a second aspect, the invention proposes an installation for converting into mechanical energy the thermal energy contained in a hot fluid coming from a hot source and a cold fluid coming from a cold source, the installation comprising at least one Device according to any one of the preceding claims, the device being in fluid connection on the one hand with the hot source and on the other hand with the cold source.

The installation may have the following characteristics, taken alone or in combination: - the axis of rotation is vertical;

the hot fluid and the cold fluid are water;

the source of hot water is water from an ocean to a first depth below the surface and the source of cold water is ocean water at a second depth below the surface greater than the first depth ;

the at least one enclosure is floating on an ocean or kept submerged at a determined depth in an ocean to overcome the effects of the swell;

the at least one enclosure rests on the ground or on the bottom of a surface of water.

It is therefore a question of generating a mist of droplets of hot fluid and of ejecting them with an initial speed. The generator and fog accelerator device can be fixed or in rotation around an axis of the enclosure.

Given the very low pressure in the chamber, the droplets partially vaporize and are therefore dispersed in their own steam.

The set of droplets and vapor is then guided and expanded through one or several nozzles, the enthalpy of the steam being transformed into kinetic energy.

Under the effect of the viscosity and friction forces which are very important compared to the mass of the droplets, given their small size, the vapor communicates a large part of this kinetic energy to the droplets which are accelerated in the nozzle (s) and communicate a push to these.

The final velocity of the droplets is low compared to that which vapor alone would have acquired for the same enthalpy drop.

The nozzles rotate about an axis and communicate this thrust to the rotating assembly.

The initial speed of the droplets, the arrangement of the nozzles and their rotational speed are arranged so as to generate an almost rectilinear trajectory of the droplets in the nozzle or nozzles, making it possible to avoid any collision with the walls of the nozzles.

Several provisions may be appropriate.

One can quote without that being limiting:

• A "turnstile" arrangement in which the distributor (s) are in rotation about the axis, the initial speed of the droplets generated by the fog generator (s) is substantially opposed to the peripheral speed due to their rotation and nozzles extend and are integral with each fog generator.

• A centrifugal "radial" arrangement in which the distributor or distributors are fixed, the initial speed of the droplets generated by the fog generator or generators has a centrifugal radial component and the nozzles in rotation about the axis are positioned at the periphery of the or fog generators.

• A centripetal "radial" arrangement in which the distributor or distributors are fixed, the initial speed of the droplets generated by the fog generator (s) has a centripetal radial component and the nozzles rotating about the axis are positioned closer to the axis of rotation as the fog generator (s).

• An "axial" arrangement in which the distributor or distributors are fixed, the initial speed of the droplets generated by the fog generator or generators has an axial component and the nozzles rotating about the axis are positioned in axial offset relative to the or fog generators.

According to particular embodiments:

• the axis of rotation is vertical;

The fog generator or generators comprise one or more plates pierced with a multitude of holes of shape, dimensions and spacing optimized to produce a fog of droplets;

· The fluids of the hot source and the cold source are water;

• the hot spring is surface water and the cold source is water from the depths of an ocean;

A generator makes it possible to transform the mechanical energy generated by the device according to the invention into electrical energy;

The generator is an electrical generator coupled directly or via a reduction box to the rotating assembly;

The generator is constituted by one or more hydroelectric units making it possible to transform all or part of the pressure energy of the hot fluid in the central pipes and supplying electrical energy;

The condensation means use condensation by direct contact between the vapor to be condensed and the fluid of the cold source;

The condensation means use the condensation at least partly without direct contact between the vapor to be condensed and the fluid coming from the cold source;

• a recuperator allows the recovery of the fresh water coming from the condensation of the steam without direct contact between the steam to be condensed and the fluid of the cold source;

· A rolling device makes it possible to support all or part of the weight of the rotating elements in the enclosure of the generator assembly and fog accelerator;

• the fog generator (s) are equipped with a cleaning device to eliminate the biofouling; • the device according to the invention is floating on the ocean or kept immersed at shallow depth to overcome the effects of the swell;

• the device according to the invention is placed on the ground or on the bottom in all or part under water, shallow;

The accompanying drawings illustrate the invention:

FIG. 1 represents, from the prior art, a diagram representing a so-called closed cycle.

FIG. 2 represents, from the prior art, a diagram representing a so-called open cycle.

FIG. 3 represents, from the prior art, a diagram representing a so-called mistlift device. FIG. 4 represents, from the prior art, a diagram showing a two-phase turbine.

Figure 5 shows a diagram of a first embodiment of the device in section seen from above.

Figure 6 shows a diagram of the device of Figure 5 in section seen from the side.

Fig. 7 shows a detailed view of a fog generator assembly of the first embodiment.

Figure 8 shows a variant of the first embodiment comprising a plurality of vertical levels.

FIG. 9 represents a diagram of a second embodiment of the device in section seen from above

FIG. 10 represents a diagram of the device of FIG. 9 in section seen from the side

FIG. 11 represents a diagram of a third embodiment of the device in section seen from above

Figure 12 shows a diagram of a fourth embodiment of the sectional device seen from the side.

The devices represented in the various figures are adapted for ΙΈΤΜ, namely that the hot fluid designated by hot water is here seawater extracted at the surface at a temperature that can generally vary between 20 and 30 ° C and the cold fluid It is referred to as cold water from seawater extracted from depths (usually between 500 and 1500m depth) and at a temperature of between 5 and 10 ° C, conditions found in the oceans of intertropical zones.

The devices described could of course operate with hot and cold fluids different from seawater or at temperatures substantially different from those indicated above with the condition of adaptations to devices obvious to a specialist.

FIG. 1 represents, in the prior art, a so-called closed cycle.

The working fluid 68 enters the evaporator 62 where it is evaporated by heat exchange with the hot water 60. It then passes into the turbine 63 where it expands providing work. It is then condensed in the condenser 64 by heat exchange with the cold water 65. The cycle ends with the pressurization of the working fluid in the liquid state by the pump 67. The main advantage of this cycle is the fact of being able to use a working fluid often ammonia with high vapor pressures at the temperatures considered, allowing turbines of reasonable size.

On the other hand, it requires exchangers capable of accepting water flows of several tens of m3 / s, with pinches of the order of a few degrees and therefore of very large size. The cost of exchangers and the associated "biofouling" problems become major constraints of this cycle.

FIG. 2 represents, from the prior art, a so-called open cycle.

The hot water 71 is partially evaporated in a flash evaporator 73 under very low pressure, for example of the order of 0.03 bar. The vapor 74 then passes through a turbine 75 where it relaxes producing work. The vapor is then condensed in a condenser 76, most often in direct contact with the cold water 77.

A vacuum pump 79 makes it possible to maintain the vacuum in the circuit by evacuating the non-condensables.

An advantage of this cycle is the use of simple and efficient evaporator and direct contact condenser.

Since the steam is at extremely low pressures, its volume density is also very low. For example, it takes about 80m ³ (cubic meter) for 1 kg (kilogram) of steam.

The volume flow rates in the turbine therefore become very important from a few MW of power and involve very high speeds and passage sections.

The current limits of turbine construction materials are then reached in terms of resistance, particularly to centrifugal forces.

Figure 3 shows an example of the so-called mistlift process.

Hot water 45 taken at the surface 46, and more precisely at a first depth below the surface 49, is ejected with an ascending vertical speed by a device 41 making it possible to produce a multitude of micro droplets in a chamber 44 inside. from which a high vacuum is maintained.

The droplets under the effect of the vacuum vaporize partially (flash vaporization). The steam is then relaxed in a vertical divergent 43 where it communicates part of its energy to water droplets by raising them against gravity.

Cold water 40 pumped from the depths, and more precisely to a second depth below the surface, greater than the first depth, is injected along the walls at mid-height of the enclosure 44 with an initial upward velocity. It is itself driven by the whole droplets and vapor upwards.

This cold water gradually condenses the vapor 95 as the vapor moves towards the upper part of the enclosure 44.

The set of cold water, droplets of hot water and remaining steam converge at the top of the chamber 44 following convergent walls of the chamber 44, where the liquid portion is discharged into the ocean. A vacuum pump 47 makes it possible to evacuate the non-condensables out of the enclosure.

The energy of the device is recovered by means of a hydraulic turbine 42 inserted into the hot water supply channel.

Although simple, this device has the disadvantage of requiring very large steam passage sections, especially given the very low density of the steam and its initial speed necessarily limited, and associated with very high heights. For example, such a 4 MW device for ΙΈΤΜ would be 20m in diameter for nearly 100m high. We imagine the difficulties of realization and operation and the cost of such a device.

In addition, the device requires, to fully extract the energy contained in the steam, a significant height of the order of 100m.

The droplets will therefore have to travel this long distance with a very high probability of collision between drops or with the walls. Indeed, although initially homogeneous, the dimensions and speeds of the drops become more and more heterogeneous as collisions and coalescence phenomena.

Each collision constitutes a loss of energy for the device. It seems that a significant loss will be made through these collisions. In addition, the largest drops will be little or not driven by the steam and may fall back into the enclosure. Finally, the convergence of the droplets to form a single jet at the top of the enclosure can not be done without a significant loss of energy.

FIG. 4 represents, in the prior art, a type of ejection device proposed for a diphasic liquid at the end of the arm or arms of a "hero" type reaction turbine.

An arm 81 carries the ejection device at its end. The fluid 80 in the liquid phase or with a low vapor fraction is first expanded through a convergent 82 in which it is accelerated and from which it leaves at a speed 83. The nucleation of vapor bubbles and a first part of their expansion can take place in this convergent 82. After passing the convergent 82, the fluid passes through a neck and into a divergent 84 of the ejection device. The divergent 84 makes it possible to continue the expansion of the fluid, in diphasic form, the vapor being created by flash evaporation.

This flash evaporation requires a large heat transfer between the liquid phase and the vapor phase. In addition, the mechanical coupling between the vapor phase accelerated by the expansion and the liquid phase is important only if the liquid is atomized into a multitude of droplets that can then be more easily driven by the vapor phase. However, for moderate temperatures of hot source and a small difference in temperature between hot source and cold source, conversion efficiencies between thermal energy and mechanical energy are necessarily low. The flow rates of hot fluid through the ejection device must therefore be very important to obtain a quantity of mechanical energy interesting industrially. For this purpose, the diameter at the neck becomes extremely large, resulting in very large lengths of the divergent portion, the divergence angle being limited to a few degrees to maintain a good flow. As a consequence, heat transfer between the liquid phase and the phase steam are poor as is the atomization of the liquid jet. Given the small contact surfaces between liquid and vapor, the central portion of the fluid remains in the form of a liquid jet with a dispersed phase consisting of vapor bubbles while the part closest to the walls is essentially composed of steam. the exception of droplets torn off the surface of the central jet. The vapor / liquid coupling is then very poor, causing significant differences between the speed 86 of the liquid 88 and the speed 87 of the vapor 85, and hence a low efficiency of the device.

By way of example, in the case of ΙΈΤΜ, with a hot source temperature of 28 ° C and a cold source temperature of 8 ° C, the required flow rate of hot fluid is about 1m ³ / s per MW electric product. If the "Hero" type turbine has four arms, the flow per injection device for a 10MW electrical installation is 2.5m ³ / s. This flow requires a diameter at the neck of the ejection device of about 0.3m and a length of the diverging portion with a divergence angle of 6 ° of nearly 60m.

It therefore clearly appears that, given the flow rates to be treated for moderate temperatures and high powers, the ejection devices proposed in the prior art are not suitable.

FIG. 5 represents a first embodiment seen in section from above of the device for converting the thermal energy of the invention into mechanical energy. It is completed by Figure 6 which shows the same device seen in side section. The drawings are purely schematic and serve the purpose of helping to understand the device.

The device is part of an installation, which may include several devices. The installation is in fluid connection on the one hand with a hot source of a so-called hot fluid and on the other hand with a cold source of a so-called cold fluid, the cold fluid being at a temperature lower than that of the hot fluid . In the examples described, the hot fluid and the cold fluid are water.

The device comprises an enclosure 1, for example such as the chamber 44 of the state of the art, but not limited to, and delimiting an internal environment. The chamber 1 has an axis 3 called rotation, fixed relative to the chamber 1. The axis 3 of rotation, when the installation is put in place, is preferably substantially vertical.

The adjective "vertical" here must be understood in reference to gravity, that is to say as designating a direction parallel to gravity.

In what follows, "axial" designate any direction parallel to the axis 3 of rotation and "transverse" designate any direction perpendicular to the axis 3 of rotation. Moreover, "radial" will designate in the following all direction, in a transverse plane, intersecting with the axis 3 of rotation, and "orthogonal" any direction, in a transverse plane, non-intersecting with the axis of rotation, with reference to components of a rotational speed about the axis 3 of rotation.

For example, the enclosure comprises a wall defining the inner medium, and of cross section to the axis 3 of substantially circular or elliptical rotation about the axis 3 of rotation. The wall of the enclosure 1 makes it possible to ensure the seal between the outside atmosphere and the interior of the the enclosure, where a partial vacuum is maintained, for example of the order of 0.013bars in the context of ΙΈΤΜ.

This enclosure 1 can be made of any material to ensure its strength and its tightness. This list may include, but is not limited to, concrete, steel, composite materials among the possible materials or a combination of these materials.

Given the large dimensions of this chamber 1, we will preferably adopt a form to best withstand the external pressure, such as partially elliptical shapes, hemispherical, cylindrical, etc.

The enclosure 1 shown in FIGS. 5 and 6 may comprise flotation means, and thus be floating on the surface of an ocean, or any other body of water, kept totally immersed between two waters by anchors or maintained partially immersed by anchors in order to overcome the constraints of the swell.

It can also be a structure placed on the ground or placed and maintained on the bottom of a body of water when the height of water is not too important, for example to overcome length of pipe supply of cold water too important.

The device comprises an inlet pipe 12 for bringing and distributing hot water inside the enclosure 1. The arrow 13 represents the arrival of hot water in the inlet pipe 12. The hot water is pumped to a first depth below the surface of the ocean, in a deep zone where the water is at maximum temperature, usually between 0 and 100m.

The device comprises a distributor 50, in fluid connection with the hot source. More specifically, according to the first embodiment, the distributor 50 comprises a first pipe 2 said central, extending along the axis 3 of rotation, and in fluid connection with the pipe 12 input. The distributor 50 also comprises a second pipe 4, said arrival, extending transversely to the axis 3 of rotation from the central pipe 2. As illustrated in FIG. 5 in particular, the distributor comprises four inlet pipes 4, distributed at 90 ° around the axis 3 of rotation, each fixed rigidly to the central pipe 2. The number and distribution of the arrival lines 4 may, however, be otherwise. The arrival pipes 4 may be rectilinear or curved.

Thus, the hot water enters the inlet pipe 12 and arrives at the arrival pipes 4 passing through the central pipe 2.

The hot water enters the central pipe 2 which is rotatably mounted about the axis 3 of rotation with respect to the enclosure 1, and more precisely, with respect to the walls of the enclosure 1.

A rotating seal 14 ensures sealing between the inlet pipe 12 and the central pipe 2 while allowing their relative rotation.

Bearings 15 equipped with the necessary means, such as bearings, stops, etc. allow to maintain the central pipe 2 substantially parallel to and aligned on the axis 3 of rotation. The pipes 2, 4, 12 may be made of any material to ensure the mechanical strength of the assembly with respect to particular centrifugal forces.

For example, without being exhaustive, steel, aluminum and composite materials may be mentioned.

The device comprises at least one generator and fog accelerator assembly, rigidly attached to the free end of an inlet pipe 4, for generating and accelerating a mist of water droplets in their own steam, inside the enclosure 1.

The generator and fog accelerator assembly comprises a receiver 5, through which the hot water arrives from the inlet pipe 4, followed by a mist generator 6, itself followed by a nozzle 7.

According to the first embodiment, each inlet pipe 4 is provided at its free end with a generator assembly and fog accelerator.

Thus, the assembly formed by the central pipe 2, the inlet pipework 4 and the generator and mist generator assemblies is said to be rotating as it pivots around the axis 3 of rotation with respect to the enclosure 1. The rotation of the rotating assembly is represented by the arrow 1 1.

The water, under the effect of the rotation of the rotating assembly, acquires pressure, and the rotation of the rotating assembly is maintained by the acceleration of the mist coming out of the nozzle which creates by reaction a thrust and causes the whole rotating in rotation.

The rotation of the rotating assembly can, if necessary, be initiated by an auxiliary device, such as a motor, or a pump putting water under pressure in the inlet pipe 4, and whose power would be reduced at as the speed of rotation of the rotating assembly increases until a determined speed is reached.

A rolling device may be associated with the rotating assembly, and generally at least with the nozzle 7. The rolling device is for example in the form of a wheel train, to accompany the rotation of the wheel. assembly rotating in the chamber 1 about the axis 3 of rotation. Optionally, the rolling device is retractable.

The pressurized hot water is received at the end of each inlet pipe 4 in the receiver 5 whose shape makes it possible to minimize the pressure losses due to the displacement of the water and to eject under the effect of the pressure. water through the fog generator 6.

The fog generator 6 may be in a first example composed of a thin metal plate that is correctly supported and pierced with a multitude of holes of a shape suitable for creating jets with a minimum of pressure drop, these jets splitting rapidly to the output of the microdroplet plate.

By way of example, the plate of the fog generator 6 may be made of stainless steel, 0.4 mm thick and pierced with a multitude of holes of conical shape with a diameter of 0.2 mm on the incoming side and 0, 1 mm of the outgoing side, spaced according to a square mesh of 2 mm of side. Such a plate makes it possible to form circular jets with a diameter of 0.1 mm, splitting rapidly into microdroplets of about 0.2 mm in diameter. These numbers are of course given as an indication and may vary widely depending on the embodiments and operation.

The liquid jets at their output from the mist generator 6 have an initial relative speed in the chamber 1 substantially equivalent in modulus to the speed of the receiver 5 due to the rotation of the rotating assembly. Given the pressure conditions, close to the saturation pressure, at the outlet of the mist generator 6, part of the water is transformed almost instantaneously into vapor by taking the energy necessary for the vaporization in the sensible heat contained in the liquid phase which cools (flash evaporation). The ejection speed of the jets of the mist generator 6, their diameter and their spacing determines the conditions of this initial flash evaporation.

It is thus obtained, almost immediately at the outlet of the mist generator 6, in the nozzle 7, a mist 8 of liquid water droplets dispersed in the steam generated by their own partial evaporation.

Depending on the conditions, the mass of vapor produced during this initial flash evaporation can reach 1, 4% by weight of the liquid mass with a density of about 70 m ³ per kg for the vapor phase. The fog generator 6, allowing the formation of micro-jets splitting microdroplets, is well suited to allow to treat very large flow rates of hot fluid, a very large contact area between vapor and liquid and a very small droplet size allowing rapid heat exchange between vapor and liquid and even inside the liquid. Flash evaporation is thus faster and more efficient.

Shortly after the output of the fog generator 6 the jets break into billions of microdroplets of the order of 0.2 mm in diameter in the previous example, separated from each other by a distance of the order of 10 times their diameter and bathed in a vapor phase of very low density. It should be noted that the vapor phase and the liquid phase have equivalent initial speeds.

The assembly is then guided in a nozzle 7, whose adapted shape makes it possible to obtain the expansion of the steam up to the pressure prevailing inside the enclosure of the order of 0.013 bar. Each nozzle 7 is oriented orthogonally to the axis 3 of rotation on the free end of the corresponding inlet pipe 4, making it possible to generate a fog 8 of billions of droplets, the fog 8 of vapor and droplets being driven by an initial velocity at the output of the mist generator 6 represented by the arrows 9, the orthogonal direction of which is approximately opposite to the orthogonal component 1 1 of the speed of rotation of the rotating assembly.

During the relaxation, the steam transforms its enthalpy into kinetic energy. The pressure and temperature of the steam gradually decrease.

A difference in speeds, called sliding speed, is established between the speed of the droplets and the velocity of the vapor, inducing frictional forces and viscosity between droplets and vapor, in the nozzle 7. Given the very low mass droplet units, the friction and viscosity forces are very much greater than the weight of these and allow a significant acceleration of the droplets. The vapor thus transmits a large part of its relaxation energy to the droplets. At the same time, as the steam cools and the pressure decreases during the expansion, the droplets continue to produce steam on their way, allowing the vapor to reach nearly 2.6% of the liquid mass.

At the outlet of nozzles 7, the droplets have thus been accelerated by the steam and have a speed greater than the rotational speed of the rotating assembly.

More than 80% of the relaxation energy of the vapor can be transferred as kinetic energy to the droplets.

As the mass of the droplets represents nearly 98% of the total mass of the fog, this kinetic energy only allowed the droplet velocity to be increased slightly, whereas if the vapor had been released alone, it would have reached very high output speeds. important because of its very low mass.

However, we know that to obtain significant efficiencies with a reaction device as described, it is necessary that the fluid velocity at the outlet of the nozzle 7 is as close as possible to the peripheral speed due to the rotation to minimize the absolute velocity of the fluid at the outlet

Thus, the effectiveness of the device presented may be greater than 75% depending on the conditions.

At the outlet of the nozzles 7, the vapor and liquid phases separate, the flow 28 of steam being sucked by the vacuum at the level of the condensation means 16 inside the chamber 1, due to a pump 19 at vacuum located downstream of the condensation means 16 with respect to the circulation of steam inside the chamber 1. The vacuum pump 19 also makes it possible to maintain the partial vacuum inside the chamber 1 while evacuating the non-condensable gases and the part of vapor that would not have condensed (arrow 26).

These condensation means 16 must allow the condensation by direct thermal exchange and / or indirectly with cold seawater from the depths, and more precisely to a second depth, greater than the first depth from which the water is pumped. hot. In the configuration of the first embodiment shown in FIGS. 5 and 6, the condensation means 16 comprise a set of pipes 17 making it possible to supply cold water 27 inside the enclosure 1 and a system 18 for spraying cold water on the steam allowing its condensation.

The spraying system 18 may be a combination of different cross flow systems, against currents, etc.

The condensation means 16 may be composed in whole or in part of indirect exchangers between the cold water and the steam allowing, if desired, to manufacture fresh water from the steam by recovering its condensed phase.

A means of recovery and evacuation of this fresh water will then have to be added in order to avoid any pollution by the cold sea water.

In the configuration shown in FIGS. 5 and 6, a recuperator 20 makes it possible to recover cold water and condensed vapor together and a pump 21 makes it possible to evacuate them outside. of the enclosure 1 (arrow 25). Similarly, a recuperator 22 can recover the hot water and a pump 23 allows to evacuate outside the enclosure.

In this configuration, has also been shown a generator 31 for transforming the mechanical energy of rotation of the rotating assembly into electrical energy. It is a rotary linear alternator 31 directly coupled to the upper part of the central pipe 2 in rotation, for example of the type that is installed on wind turbines. This choice makes it possible to dispense with a very expensive reduction box and seems interesting considering the rotational speeds envisaged. This alternator 31 can of course be installed inside the enclosure 1 or outside thereof, provided that the central pipe 2 is extended by a rotating axis. A conventional generator / reduction box system can also be considered.

It is also conceivable to recover the rotational mechanical energy of the rotating assembly and to convert it into electrical energy by means of a hydroelectric group.

For example, the hydroelectric group 33 may be inserted into the central pipe 2 of hot fluid when it comes under pressure as illustrated in FIG. 8. Alternatively, several hydroelectric groups may be inserted in each of the inlet pipes 4, using the pressurization generated by the rotation of the rotating assembly

It can also be envisaged that only propellers or hydraulic wheels are inserted in each of the arrival lines 4, a transmission system making it possible to reduce all the collected mechanical energy to a single generator.

It is also conceivable to set a generator and fog accelerator assembly to several lines 4 of arrival.

FIG. 7 represents a schematic view of the rotating assembly and in particular of its elements 4, 5, 6 and 7.

It is very important for the efficiency of the device to minimize the pressure drops in the arrival lines 4 and the receiver 5. The shapes and sections adapted to this imperative will therefore be chosen for these elements.

In the same way, the fog generator 6 must have a minimum pressure drop. The shape of the holes, their diameter, their spacing, the material constituting the fog generator will also be adapted to this imperative.

The formation of a multitude of micro-jets at the output of the mist generator 6 makes it possible to create the mist in which the continuous phase is the vapor 8 and the dispersed phase the droplets.

This multitude of droplets has a contact surface with steam very favorable to heat exchange.

The nozzle 7 will usually be of divergent shape allowing the droplets in their rectilinear trajectory not to hit the walls.

An angle A between the orthogonal speed 1 1 due to the rotation of the rotating assembly and the speed of ejection of the fluid at the output of the mist generator 6 has been represented in FIG. 7. It is indeed necessary to prevent the liquid droplets, after their ejection from the nozzle 7, to strike the next receiver 5 according to the direction of rotation.

One solution may be to provide a non-zero angle A, so that the liquid droplets are ejected with a component to the periphery sufficient to prevent them from colliding with the next receiver. This angle should be minimum to minimize the loss of power. An angle of 5 ° to 15 ° may be suitable in some configurations.

An ejection in any other direction than the periphery could also be suitable provided to prevent any percussion with the rotating assembly.

In order to fully understand all the advantages provided by the device that is the subject of the present invention, it is advantageous to detail an exemplary embodiment of such a device.

It should be noted that the figures given above are purely indicative and depend largely on the hypotheses chosen.

Consider the device object of the present invention used in the context of ΙΈΤΜ with a hot water temperature of 25 ° C and cold water of 8 ° C at the inlet of the device.

Flow rates are 10m ³ / s for hot and cold water.

The device has a turning radius of 20m for a rotational speed of 3rd / s (radians per second).

The peripheral speed due to rotation is 60m / s.

Taking into account an optimized geometry, the pressure of the hot water due to the rotation is 17.9 bar in the receiver 5 resulting in a speed of ejection of 59.9m / s at the output of the fog generator 6 taking into account the pressure losses through this fog generator and the fact that the pressure at the outlet of this fog generator is much lower than the atmospheric pressure. As can be seen, the ejection speed 9 is very close to the peripheral speed.

For a drop diameter of 0.2 mm corresponding to holes with a diameter of 0.1 mm and a mean sliding speed between droplets and vapor of 80 m / s, the friction and viscosity forces acting on each drop are 10 times greater than the weight of each droplet allowing an acceleration of nearly 230m / s ² of the droplets.

A nozzle of about 4m in length would then produce an average droplet velocity of 74 m / s at a speed of 168 m / s.

Under these conditions, about 85% of the enthalpy loss of the vapor was communicated to the drops as kinetic energy.

The raw efficiency of the device at the outlet of the nozzle 7 is 83%, allowing a net efficiency of 62% taking into account the consumption of the devices for pumping fluids and maintaining the vacuum.

The mechanical power restored is 7000 KW.

First of all, it can be seen that the exit velocity of the droplets, which represents 98% of the mass ejected, is very close to the peripheral speed, which allows the excellent efficiency of the device. A conventional steam turbine or two-phase turbine device without significant liquid phase / vapor coupling would result in vapor velocities of nearly 400m / s

To obtain equivalent peripheral speeds, it would then be necessary to have very high speeds of rotation consequently resulting in unacceptable centrifugal forces for the rotating elements.

The device presented thus makes it possible while maintaining a high efficiency to limit the rotational speeds and the centrifugal forces thanks to an excellent mechanical coupling of the liquid and vapor phase.

The dimensions, rotational speeds, masses and centrifugal forces remain in the values found in the medium power wind turbine.

In the example considered, the output speeds of the fog generator 6 however remain sufficiently high (approximately 60 m / s) to allow moderate sections of the mist generator 6.

The device according to the invention makes it possible to choose the speed of rotation and the radius of the rotating assembly as well as the dimensions of the drops produced and the length of the nozzle 7 making it possible to find the best compromise between the following constraints:

fog generator output speeds 6 and high nozzles 7 allowing limited sections,

good steam / water coupling for good efficiency and

- acceptable centrifugal forces to cite only some of the criteria.

The path length of the droplets in the proposed device is very limited, limiting the numbers of collisions between drops and with the walls, a source of significant energy losses, unlike devices proposing a vertical elevation of the liquid phase necessitating pathways. 100m.

It avoids expensive indirect heat exchangers and gigantic closed cycle solutions and requires only materials available everywhere, inexpensive with little manufacturing constraints.

Alternatively, and in a second example, the fog generator 6 may comprise a multitude of two-phase nozzles, of the order of several thousand, each comprising at least one convergent corresponding to a hole of the plate-shaped mist generator 6, previously presented, a neck and a divergent in which a two-phase diphasic relaxation takes place. The two-phase nozzles are contiguous to each other and arranged so that there is the minimum of discontinuity between the sum of the output sections of the two-phase nozzles and the section immediately downstream. The two-phase nozzles may or may not be extended by a complementary expansion nozzle, for example the nozzle 7 previously presented, common to all the two-phase nozzles, when the entire expansion has not been performed in the multitude of nozzles Two phase.

FIG. 9 represents a second embodiment seen in section from above of the device proposed by the present invention. It is completed by the figure 10 which represents this same device seen in side section. The drawings are purely schematic and serve the purpose of helping to understand the device.

In this configuration, unlike the configuration according to claim 2 shown in Figures 5, 6 and 7, the distributor 50 which includes the pipes 2 and 4 is fixed relative to the chamber 1.

The hot water is admitted into the stationary central pipe 2 which distributes it in the fixed supply lines 4 with respect to the chamber 1 as well. These delivery lines 4 convey water to the periphery to a receiver 5.

In the second embodiment, the receiver 5 has a cylindrical annular shape with an axis 3 and makes it possible to distribute the hot water over the entire periphery to the mist generator 6. Thus, the receiver 5 and the mist generator 6 according to FIG. second embodiment are common to all of the inlet pipe 4, and are rigidly fixed to the inlet pipes 4.

Under the effect of the initial pressure of the hot fluid, the mist generator 6 generates a mist 8 of droplets, dispersed in their own vapor and driven by an initial speed 9 having a centrifugal component, that is to say say radial towards the periphery of the enclosure 1.

Under the effect of this centrifugal speed, the droplets move away from the axis 3 of rotation.

The assembly rotating about the axis 3 of rotation comprises partitions 91 parallel to the axis 3 progressively away from it by forming a spiral portion and integral with two upper and lower plates 92, extending transversely. The combination of two partitions 91 forms a nozzle 7.

According to the example illustrated in Figure 9, the device comprises two nozzles 7, each being defined between two spiral partitions 91. The number of partitions 91 determines the number of nozzles 7 carried by the rotating assembly.

The rotating assembly is provided with seals 14 and bearings 15 on the central pipe 2 necessary for its rotation.

When this rotating assembly rotates about the axis 3 of rotation in the direction indicated by the arrow 1 1, the droplets ejected from the mist generator 6 move towards the periphery of the enclosure 1.

The centrifugal radial velocity of the droplets, the speed of rotation of the rotating assembly and the shape of the spiral of the nozzles 7 are determined so that the fog 8 of droplets fills the space between the fog generator 6 and partitions 91 tuyeres 7 without reaching those ci.

During rotation of the rotating assembly, the droplets and their vapor enter the nozzle 7 where they relax.

As in the device of FIG. 5 described above, the droplets are then accelerated by the vapor which expands to the outlet of the nozzle 7. The arrow 90 represents the relative speed with respect to the rotating assembly 30 of the drops. nozzle outlet. The accelerated fluid exiting the nozzle creates by reaction a thrust that drives the rotating assembly.

The means for condensing the steam, maintaining the vacuum in the chamber 1 and the evacuation of the fluids are similar to those of the configuration shown in FIGS. 5 and 6, and are shown in FIG. 10 using the same references. .

A generator 31 such as a rotary linear alternator driven in rotation by the rotating assembly makes it possible to transform the mechanical energy of the nozzles 7 into rotation in "enclosure 1

As in the configuration shown in FIG. 8, the device can have several levels of assemblies 4, 5, 6, 91, 92 and 7 along the axis 3.

Figure 1 1 shows a third embodiment seen in section from above the device according to the invention. The drawings are purely schematic and serve the purpose of helping to understand the device.

In this configuration, the fixed distributor 50, not shown, can bring the hot water to a receiver 5.

In the example shown, the receiver 5 has a cylindrical annular shape of axis 3 and distributes the hot water over the entire periphery of a fog generator 6, located at the periphery of the rotating assembly. The rotating assembly comprises, in a manner similar to the rotating assembly of the second embodiment, nozzles 7, in this case two nozzles 7 in the illustrated example, each nozzle 7 being formed by two partitions 91 parallel to the axis 3 of rotation, progressively approaching it by forming a spiral portion and secured to two upper and lower trays 92.

Under the effect of the initial pressure of the hot fluid, the mist generator 6 generates a mist of droplets, dispersed in their own vapor and driven at an initial speed 90 having a centripetal radial component, that is to say say towards the axis 3 of rotation.

Under the effect of this speed, the droplets approach the axis 3.

The assembly turning around axis 3 is composed of partitions 91.

The number of partitions 91 determines the number of nozzles 7 carried by the rotating assembly

30.

When this rotating assembly rotates about the axis 3 of rotation in the chamber 1, in the direction indicated by the arrow 1 1, the droplets ejected from the device 6 move towards the axis 3 of rotation.

The centripetal radial velocity of the droplets, the speed of rotation of the rotating assembly and the shape of the spiral are determined so that the mist of droplets fills the space between the mist generator 6 and the septa 91 of the nozzles 7 without reaching those.

As in the device of FIG. 5 previously described, the droplets are then accelerated by the vapor which expands to the outlet of the nozzle 7. The arrow 90 represents the relative speed with respect to the rotating assembly of the drops in FIG. the nozzle. The accelerated fluid exiting the nozzle creates by reaction a thrust that drives the rotating assembly.

The means for condensing the vapor, maintaining the vacuum in the chamber 1 and the evacuation of the fluids are arranged so as to allow the condensation of the steam leaving the nozzles 7, maintaining the vacuum after condensation of the vapor and evacuation of hot and cold fluids. They can be arranged inside the rotating assembly or outside thereof, pipes for the transport of different fluids.

FIG. 12 represents a fourth embodiment seen in side section of the device according to the invention.

In this configuration, unlike the configuration of the first embodiment shown in Figures 5, 6 and 7, the distributor 50 which includes the central pipes 2 and 4 of arrival is fixed relative to the chamber 1.

Hot water is admitted into the stationary central pipe 2 which distributes it in the fixed supply lines 4. These inlet pipes 4 convey the water to the periphery each to a common receiver 5, fixed to the pipes 4 of arrival.

In the example presented, the receiver 5 has a cylindrical annular shape with axis 3 of rotation and makes it possible to distribute the hot water on its lower surface to a mist generator 6.

The latter under the effect of the initial pressure of the hot fluid makes it possible to generate a mist of droplets, dispersed in their own vapor, the mist being animated with an initial velocity 9 at the output of the mist generator 6 having a downward axial component.

Under the effect of this axial speed, the droplets move away from the receiver 5.

The assembly rotating about the axis 3 comprises a cylindrical central hub extended by a set of nozzles 7 formed by a set of radial blades.

The rotating assembly is provided with seals and bearings 15 on the central pipe 2 necessary for its rotation.

When this assembly rotates about the axis 3 in the direction indicated by the arrows 1 1, the droplets ejected from the device 6 move downwards.

The axial speed of the droplets, the speed of rotation of the rotating assembly and the shape of the nozzles are determined so that the mist of droplets flows through the nozzles 7 without touching their partitions.

During the rotation of the rotating assembly, the droplets and their vapor penetrate into the nozzles 7 where they relax.

As in the device of Figure 5 described above, the droplets are then accelerated by the vapor which expands to the outlet of the nozzles.

The accelerated fluid leaving the nozzles 7 creates by reaction a thrust transverse to the axis 3 of rotation which drives the rotating assembly. The means for condensing the steam, maintaining the vacuum in the chamber and the evacuation of the fluids are the same as those of the configuration of the first embodiment shown in FIGS. 5 and 6.

The generator 31 for converting the mechanical energy into electrical energy shown is a rotary linear alternator driven in rotation by the rotating assembly.

As in the configuration shown in FIG. 8, the device can have several levels of assemblies 4, 5, 6 and 30 along the axis 3.

The device proposed according to the invention makes it possible to transform into mechanical energy the thermal energy contained in two fluids with a small temperature difference with good efficiency and a simple and inexpensive device.

It is particularly adapted to the thermal energy of the seas and geothermal energy.

Claims

1. Device for converting into mechanical energy the thermal energy contained in a hot fluid from a hot source and a cold fluid from a cold source, the hot fluid being at a temperature higher than that of the cold fluid, the device comprising at least one external pressure-resistant enclosure (1) defining an internal medium, the device further comprising, inside the at least one enclosure (1), at least:

a distributor (50) rotating or not about an axis (3) of rotation in the enclosure (1), comprising an inlet intended to be in fluid connection with the hot source outside the enclosure (1 );

an assembly (30) generating and accelerating fog inside the chamber (1), the mist comprising a mixture of droplets and steam, the assembly (30) generator and fog accelerator being supplied with hot fluid by the dispenser (50),

condensation means (16), adapted to be in fluid connection with the cold source, for condensing by cooling with the fluid of the cold source of the vapor produced inside the chamber;

means for evacuating fluids from the enclosure (1);

the device being characterized in that the assembly (30) generator and fog accelerator comprises at least:

- A mist generator (6), in fluid connection with the distributor (50) for generating a mist of hot fluid droplets animated with an initial velocity and dispersed in the vapor formed by their own partial evaporation;

a nozzle (7) rotatably mounted about the axis (3) of rotation relative to the chamber (1) for relaxing and guiding inside the chamber (1) the mist of droplets and steam generated by the mist generator (6), the at least one nozzle (7) extending at least partially in a direction transverse to the axis (3) of rotation so that the fog flow causes reaction by rotation the nozzle (7) around the axis (3) of rotation.

2. Device according to claim 1 characterized in that the at least one distributor (50) and the at least one generator (6) of fog are rigidly attached to the at least one nozzle (7), rotating about the axis (3) of rotation, the at least one nozzle (7) being in the extension of the at least one mist generator (6), the at least one mist generator (6) being oriented with respect to the axis (3) in such a way that the initial relative velocity with respect to the mist generator (6) of the droplets generated by the at least one mist generator (6) comprises a component transverse to the axis (3) of rotation which is substantially opposite to the orthogonal component of the speed of rotation of the at least one nozzle (7) around the axis (3) of rotation.

3. Device according to claim 1 characterized in that the at least one distributor (50) is fixed relative to the enclosure (1), the initial speed of the droplets generated by the at least one fog generator (6) having a radial centrifugal component and the at least one nozzle (7) rotating about the axis (3) is positioned at the periphery of the at least one fog generator (6).

4. Device according to claim 1 characterized in that the at least distributor (50) is fixed in the chamber (1), the initial speed of the droplets generated by the at least one mist generator (6) having a centripetal radial component and the at least one nozzle (7) rotating about the axis (3) is positioned closer to the axis (3) than the fog generator (s) (6).

5. Device according to claim 1 characterized in that the or distributors (50) are fixed in the chamber (1), the initial speed of the droplets generated by the at least one mist generator (6) having a parallel axial component to the axis (3) of rotation and the at least one nozzle (7) rotating about the axis (3) being positioned axially offset relative to the at least one fog generator (6).

6. Device according to any one of the preceding claims characterized in that the axis of rotation (3) is vertical.

7. Device according to any one of the preceding claims characterized in that the at least one fog generator (6) comprises at least one plate pierced with a multitude of holes of shape, size and spacing specially optimized to produce a mist of droplets.

8. Device according to any one of the preceding claims characterized in that the at least one fog generator (6) comprises at least a plurality of two-phase nozzles, each two-phase nozzle comprising at least one convergent, a neck and a divergent, the two-phase nozzles being contiguous to each other.

9. Device according to any one of the preceding claims, characterized in that the fluids of the hot source and the cold source are water.

10. Device according to any one of the preceding claims, characterized in that the hot source is the surface water and the cold source water from the depths of an ocean.

1 1. Device according to any one of the preceding claims characterized in that it comprises a generator (31, 33) for transforming the mechanical energy generated by the rotation of the at least one nozzle (7) into electrical energy.

12. Device according to claim 1 1 characterized in that the generator (31, 33) is an electric generator coupled directly or via a reduction box to the axis (3) of rotation of the at least one nozzle (7).

13. Device according to claim 1 1 characterized in that the generator (31, 33) comprises one or more hydroelectric groups for transforming all or part of the pressure energy of the hot fluid in the distributor (50) into electrical energy.

14. Device according to any one of the preceding claims characterized in that the means (16) of condensation use condensation by direct contact between the vapor to be condensed and the fluid of the cold source.

15. Device according to any one of claims 1 to 12 characterized in that the means (16) of condensation use condensation at least partly without direct contact between the steam to be condensed and the fluid from the cold source.

16. Device according to claim 14 characterized in that it comprises at least one recuperator (35) for the recovery of fresh water from the condensation of steam without direct contact between the steam to be condensed and the source fluid cold.

17. Device according to any one of the preceding claims characterized in that it comprises at least one rolling device for supporting all or part of the weight of the at least one nozzle (7).

18. Device according to any one of the preceding claims, characterized in that the at least one mist generator (6) is provided with a cleaning device (96) for eliminating biofouling.

19. Device according to any one of the preceding claims characterized in that it comprises flotation means.

20. Installation for converting into mechanical energy the thermal energy contained in a hot fluid from a hot source and a cold fluid from a cold source, the installation comprising at least one device according to any one of the claims. previous, the device being in fluid connection on the one hand with the hot source and on the other hand with the cold source.

21. Installation according to claim 20, wherein the axis (3) of rotation is vertical.

22. Installation according to claim 20 or claim 21, wherein the hot fluid and the cold fluid are water.

23. Installation according to any one of the preceding claims, wherein the source of hot water is water from an ocean to a first depth below the surface and the source of cold water is water from the water. ocean at a second depth below the upper surface at the first depth.

24. Installation according to any one of claims 21 to 23, wherein the at least one chamber is floating on an ocean or kept immersed at a given depth in an ocean to overcome the effects of waves.

25. Installation according to any one of claims 21 to 24, wherein the at least one enclosure rests on the ground or on the bottom of a surface of water.