FR3139865A1 - Differential evaporation system - Google Patents

Abstract

Title: Evaporation amplifier The invention relates to a differential evaporation engine system comprising an enclosure (11) having a cavity capable of containing a liquid (2), and a gas mixture (3), a hot source (14) configured to heat the liquid (2), a cold source (15) configured to cool the gas mixture (3), a mobile element configured to move inside the enclosure (11), the mobile element comprising at least a plunger element (122), the plunger element (122) being configured so as to be at least partially immersed in the liquid (2) in a first configuration and alternatively in contact with the gas mixture (3) in a second configuration. the at least one plunger element (122) has a porous surface (122a), so as to increase the evaporation surface without increasing the surface of the liquid (2). Figure for abstract: Fig. 2B

Description

Differential evaporation system

The present invention relates to the field of energy transformation devices and more particularly to machines and heat engines. The invention will find a particular application in engines with differential evaporation pressure.

STATE OF THE ART

In the field of engines, the Stirling engine is well known, which uses a temperature difference applied to a gas in a closed enclosure to produce mechanical energy. Motors reproducing a Rankine cycle by converting heat into mechanical work are also known. However, these motors have the disadvantage of often presenting unsatisfactory efficiencies.

There are solutions capable of being used in an engine, such as that of document WO2016034632A1 presenting a differential evaporation engine comprising: an enclosure with a liquid and a working mixture, a cold source capable of cooling the working mixture, a hot source configured to heat the liquid, a mobile element, arranged inside the enclosure so as to create conditions for evaporation of the liquid or condensation of the working mixture.

This type of engine is configured in such a way that a heat exchange occurs between the working mixture and the hot and cold sources. This type of engine has high efficiency and many advantages. Naturally it would be advantageous to further improve the efficiency and/or power of this type of engine.

An object of the present invention is therefore to propose a solution which makes it possible to increase the efficiency and/or the power of differential evaporation engines.

The other objects, characteristics and advantages of the present invention will appear on examination of the following description and the accompanying drawings. It is understood that other benefits may be incorporated.

SUMMARY

• une enceinte présentant une cavité apte à contenir un liquide, et un mélange gazeux,
• une source chaude configurée pour chauffer le liquide,
• une source froide configurée pour refroidir le mélange gazeux,
• un élément mobile configuré pour se déplacer à l’intérieur de l’enceinte, l’élément mobile comprenant au moins un élément plongeur, l’élément plongeur étant configuré de sorte à être au moins partiellement immergé dans le liquide dans une première configuration et alternativement au contact du mélange gazeux dans une deuxième configuration, la deuxième configuration étant différente de la première configuration, dans la deuxième configuration l’élément plongeur étant non immergé dans le liquide ou étant moins immergé dans le liquide que dans la première configuration.

To achieve this objective, according to one embodiment, a differential evaporation engine system is provided comprising:

• an enclosure having a cavity capable of containing a liquid and a gas mixture,
• a hot source configured to heat the liquid,
• a cold source configured to cool the gas mixture,
• a movable element configured to move inside the enclosure, the movable element comprising at least one plunger element, the plunger element being configured so as to be at least partially immersed in the liquid in a first configuration and alternatively in contact with the gas mixture in a second configuration, the second configuration being different from the first configuration, in the second configuration the plunger element being not immersed in the liquid or being less immersed in the liquid than in the first configuration.

The motor is configured so that the at least one plunger element has a porous surface, the plunger element being configured so that in the first configuration the porous surface is impregnated with a portion of the liquid and in the second configuration said portion of the liquid evaporates at least partially on contact with the gas mixture.

The divers make it possible to increase the evaporation surface of the liquid in contact with the gas mixture without increasing the volume of the enclosure. In other words, the present invention makes it possible to maintain a constant working volume while increasing the imbibition surface on which a phenomenon of evaporation and/or condensation occurs. This leads to an increase in engine efficiency and/or power to an unexpected extent.

The invention preferably makes it possible not to increase the parasitic work volume of a differential evaporation engine by increasing its evaporation or condensation surface.

Unlike a Stirling engine, this technical solution allows operation with a much lower volume of gas mixture displaced.

Thus, we obtain a reduced size of the entire differential evaporation motor for a power equivalent to a larger motor. The invention allows an improvement of all systems using the phenomena of evaporation and/or condensation.

Without being aware of the present invention, those skilled in the art would increase the power of differential evaporation engines by increasing, for example, the powers of the hot and cold sources or even the size of the mobile element.

Thus, the present invention makes it possible to avoid having to increase the surface area of the liquid, or to increase the size of the enclosure where the heat exchanges take place.

BRIEF DESCRIPTION OF THE FIGURES

The aims, objects, as well as the characteristics and advantages of the invention will emerge better from the detailed description of an embodiment of the latter which is illustrated by the following accompanying drawings in which:

Figures 1A and 1B represent a sectional view of an example of a differential evaporation engine system having a movable element capable of being driven in translation and not comprising plunger elements respectively in a second and in a first configuration.

Figures 2A and 2B represent a sectional view of an example of a differential evaporation engine system having a movable element capable of being driven in translation and comprising plunger elements respectively in the second configuration and in the first configuration.

Figures 3A and 3B respectively represent a sectional view of an example of a differential evaporation engine having a movable element capable of being driven in translation and comprising plunger elements fixed on the movable element as well as additional plunger elements fixed to the inside the enclosure in a second configuration and in a first configuration.

Figures 4A and 4B respectively represent a front and side sectional view of an example of a differential evaporation engine system having a movable element and comprising plunger elements capable of being rotated along a transverse axis.

The drawings are given as examples and are not limiting to the invention. They constitute schematic representations of principle intended to facilitate the understanding of the invention and are not necessarily on the scale of practical applications. The cylinders or pistons are not represented in the drawings. For the sake of clarity, only the displacer is shown.

DETAILED DESCRIPTION

Before beginning a detailed review of embodiments of the invention, the following are set out as optional characteristics which may possibly be used in combination or alternatively:

According to one example, the enclosure is configured so that the liquid is overcome by the gas along a main axis and that the mobile element moves by a translation movement along the main axis.

According to an example, the main axis is vertical.

According to one example, the plunger element extends mainly in a direction parallel to the main axis.

According to one example, the movable element comprises a main portion having a lower surface normal to the main axis and the at least one plunger element extends from the lower surface, preferably the plunger element having a rod shape.

According to one example, the enclosure comprises at least one additional plunger element fixed relative to the enclosure and having an additional porous surface portion, the at least one additional plunger element extending into the enclosure from a lower enclosure face of the enclosure in a direction parallel to the main axis.

Preferably the additional plunger elements are fixed relative to a high portion of the enclosure along the main axis.

According to one example, the main portion of the movable element defines a reservoir configured to contain an additional liquid and the motor is configured so that in the second configuration, the at least one additional plunger element soaks up the additional liquid .

According to one example, the motor comprises a plurality of additional plunger elements.

According to one example, the enclosure is configured so that the liquid is overcome by the gas along a main axis and that the mobile element moves by a rotational movement along a secondary axis, orthogonal to the main axis.

According to one example, the porous surface covers the entire surface of the at least diving element.

According to one example, the motor comprises a plurality of plunger elements.

According to one example, the plunger elements are spaced apart from each other so as to create a passage space for the gas in order to optimize the evaporation of the liquid soaked on the porous surface by contact with the gas.

According to one example, the plunger elements are equidistant from each other.

According to one example, at least one plunger element is a rod and/or a cylinder. According to one embodiment, at least one plunger element has a hollow portion.

According to one example, at least one plunger element has at least one opening configured to allow circulation of the liquid or the gas mixture during the passage of the motor from one of the first configuration and the second configuration to the other of the first configuration and the second configuration.

Preferably the plunger element is a hollow tube having side openings.

According to one example, the plunger element is made of wood, or a composite material or sponge, or a fabric.

According to one example, the plunger element is made of oxidized metal.

According to one example, the plunger element is made of a material having a thermal conductivity less than or equal to 10 W · m^–1·K^-1 (Watt / (meter *kelvin)).

This makes it possible in particular not to interfere with the evaporation and condensation process with the gas mixture. Indeed, the evaporation of the liquid would cool a diver with high thermal conductivity and would cool the heating liquid during its reintegration into the liquid.

According to one example, the porous surface of the at least one plunger element is entirely made of a porous material and takes the form of at least one of the following typologies: streaks, strips, grids, sticks, sponges or mesh.

According to one example, the cavity has a constant volume.

According to one example, the cavity extends along a main axis between a heating space and a cooling space so that the hot source can heat the liquid in the heating space via the side and/or lower faces and that the cold source can cool the gas mixture in the cooling space.

It is specified that in the context of the present invention, the term differential evaporation engine can be understood as only a constituent portion of the engine. Thus it could essentially be the enclosure where the movement of the mobile element takes place thanks to the pressure differential created by the hot and cold sources.

Partial imbibition of a liquid will mean an action allowing the contact surface of the mobile element to be soaked with the gas mixture by the liquid and therefore the gripping of the liquid by the mobile element or the deposit of the liquid on the liquid. mobile element. In other words, a quantity of liquid is taken from the first configuration to the second configuration.

By “mobile element” or “displacer” we mean a part that can move within the enclosure and can include diving elements.

The term “plunger element” means solid elements integral with the movement of the mobile element.

It is specified that, in the context of the present invention, the terms "on", "surmounts", "covers", "underlying", "vis-à-vis" and their equivalents do not necessarily mean "at the contact of”.

The terms “substantially”, “approximately”, “of the order of” mean “within 10%, preferably within 5%” or, when it comes to an angular orientation, “within 10° ". Thus, a direction substantially normal to a plane means a direction having an angle of 90±10° relative to the plane.

In the present patent application, the term mobile corresponds to a rotational movement or a translational movement or even to a combination of movements, for example the combination of a rotation and a translation.

• positionnées à distances l’une de l’autre, et/ou
• mobiles l’une par rapport à l’autre et/ou
• solidaires l’une de l’autre en étant fixées par des éléments rapportés, cette fixation étant démontable ou non.

In the present patent application, when it is indicated that two parts are distinct, this means that these parts are separate. They are :

• positioned at distances from each other, and/or
• mobile relative to each other and/or
• secured to each other by being fixed by attached elements, this fixing being removable or not.

A one-piece unitary part cannot therefore be made up of two separate parts.

In the present patent application, the term "integral" used to describe the connection between two parts means that the two parts are linked/fixed relative to each other, according to all degrees of freedom, unless it is explicitly specified differently. For example, if it is indicated that two parts are united in translation in a direction piece in direction X, the other piece performs the same movement.

In the detailed description which follows, use may be made of terms such as “horizontal”, “vertical”, “longitudinal”, “transverse”, “upper”, “lower”, “top”, “bottom”, “front », “rear”, “inside”, “outside”. These terms must be interpreted relatively in relation to the normal position of the differential evaporative engine system and the normal direction of travel of the user of the assembly.

As illustrated in Figures 2A to 4B, there is shown an example of a differential evaporation engine system 1 comprising an enclosure 11 capable of containing a liquid 2 and a gas mixture 3. The liquid 2 and the gas mixture 3 being advantageously distributed so that the gas mixture 3 overcomes the liquid 2 along the main axis Y ₁ . Preferably, the liquid 2 extends from the bottom of the enclosure 11 and comprises a superficial surface 2a in contact with the gas mixture 3.

System 1 includes a hot source 14 configured to heat the liquid 2 present in the heating space. The hot source 14 includes for example a heating element. The system 1 also includes a cold source 15 configured to cool the gas mixture 3 in a cooling space. The cold source 15 includes for example a cooling element. By cold source we can understand a source allowing the enclosure 11 to be cooled from the ambient temperature of the engine. By hot source we can understand a source allowing the enclosure 11 to be heated from an ambient temperature of the engine.

Preferably, the heating element and/or the cooling element belong to the engine.

The system includes a mobile element 12 configured to move inside the enclosure 11. For the sake of clarity, the hot source 14 and the cold source 15 have not been shown in the figures.

According to a first embodiment illustrated in Figures 2A to 3B, the movable element 12 is configured to move in translation along the main axis Y _1. The movable element 12 preferably comprises a main portion 121 located at the end d a drive shaft 123. According to an example, in the first configuration, the main portion 121 is closer to the heating zone and therefore to the liquid 2. In the second configuration, the main portion 121 is further away from the heating zone and therefore further away from liquid 2 than in the first configuration. The heating zone being distinct and distant from the cooling zone and the first configuration being different from the second configuration.

Preferably, the evaporation of liquid 2 takes place at the surface surface 2a of the liquid in contact with the gas mixture 3. The quantity of liquid 2 evaporated being proportional to said surface surface 2a.

According to one example, in the second configuration said portion of the liquid evaporates entirely on contact with the gas mixture. According to an alternative example, in the second configuration said portion of the liquid partially evaporates on contact with the gas mixture.

Advantageously, liquid 2 is hot water. The use of water is particularly known for its very high thermal capacity. Other liquids with optimal evaporation capacities relative to their temperature may also be used, such as alcohol for example.

According to one example, the gas mixture 3 is water vapor. It can also be vapor from other mixtures whose liquid states have evaporation temperatures different from the evaporation temperature of water.

As illustrated in Figures 2A and 2B and according to a preferred embodiment of the present invention, the movable element 12 comprises at least one plunger element 122. Preferably, the movable element 12 comprises a plurality of plunger elements 122. plunger elements 122 being configured so as to be at least partially immersed in the liquid 2 in a first configuration shown in and alternatively not immersed or less immersed in the liquid 2 and more in contact with the gas mixture 3 in a second configuration than in the first configuration represented in . According to this embodiment, the plunger elements 122 are configured to move in translation along the main axis Y _1.

Preferably, at least one plunger 122 comprises a porous surface 122a configured to impregnate the liquid 2 so as to increase the surface of liquid 2 in contact with the gas mixture 3 and amplify the evaporation phase. In fact, the performance of the system is optimized.

When the displacer 12 moves away from the heating zone, it exposes the plunger elements 122 to the gas mixture so as to promote the evaporation of the liquid 2 soaked on the porous surfaces 122a.

When the displacer 12 moves away from the cooling zone, it exposes the plunger elements 122 to the gas mixture 3 in the cooling zone for the condensation phenomenon.

During operation of the engine, the plunger elements 122 are alternately immersed in and taken out of the liquid 2 while being driven by the movable element 12.

During the immersion phase which corresponds to the first configuration, the porous surfaces 122a of the diving elements 122 capture the heat of the liquid 2 called “heating liquid”. The at least one porous surface 122a being immersed in the liquid 2 so as to be impregnated with it.

During the evaporation phase corresponding to the second configuration, the plunger elements 122 emerge from the liquid 2 so that the at least one porous surface 122a soaked in hot liquid 2 becomes exposed in contact with the gas mixture 3 to allow optimal evaporation .

Preferably, the plunger elements 122 respectively comprise porous surfaces 122a and the total of these porous surfaces 122a is preferably greater than the surface surface 2a of the liquid 2. Thus all of the porous surfaces 122a are added to the surface surface 2a in order to optimize the evaporation of liquid 2.

This process can also be reproduced by analogy to increase the condensation of an evaporated volume of liquid 2. In this case, the liquid 2 in which the plunger elements 122 are immersed is cooled.

As illustrated in Figures 3A and 3B and in the same manner as in the previous embodiment, the movable element 12 comprises plunger elements 122 fixed on the lower face 121a and configured to immerse themselves in the hot liquid 2 in the heating space.

According to this embodiment, the movable element 12 comprises a rim 124 and an upper face 121b. The upper face 121b preferably being a face opposite and parallel to the lower face 121a. The rim 124 extending from the upper face 121b so as to define a volume also designated reservoir 121c capable of containing an additional liquid 4.

• une première configuration illustrée à la , dans laquelle les éléments plongeurs 122 sont immergés dans le liquide 2 et les plongeurs additionnels 112 sont à découvert. Dans cette configuration les surfaces imbibées des plongeurs additionnels 112 à découvert sont froides car elles viennent de tremper dans le liquide additionnel 4 à proximité de la source froide. Elles transmettent alors de la chaleur négative, participant à la condensation du mélange gazeux 3. Dans cette configuration, les surfaces des éléments plongeurs 122 sont dans le liquide 2 et n’ont pas d’influence sur cette configuration de condensation.
• Une deuxième configuration illustrée à la , dans laquelle, les surfaces des éléments plongeurs 122 sont à découvert et les plongeurs additionnels 112 sont dans le liquide additionnel 4. Dans cette configuration, les surfaces des éléments plongeurs 122 sont imbibés de liquide chaud et transmettent ainsi de l’énergie d’évaporation. Les plongeurs additionnels n’influent pas durant cette configuration d’évaporation car ils sont plongés dans le liquide additionnel 4.

Thus, the system alternates between two configurations:

• a first configuration illustrated in , in which the plunger elements 122 are immersed in the liquid 2 and the additional plungers 112 are exposed. In this configuration the soaked surfaces of the additional divers 112 exposed are cold because they have just been soaked in the additional liquid 4 near the cold source. They then transmit negative heat, participating in the condensation of the gas mixture 3. In this configuration, the surfaces of the plunger elements 122 are in the liquid 2 and have no influence on this condensation configuration.
• A second configuration illustrated in , in which the surfaces of the plunger elements 122 are exposed and the additional plungers 112 are in the additional liquid 4. In this configuration, the surfaces of the plunger elements 122 are soaked in hot liquid and thus transmit evaporation energy . The additional plungers have no influence during this evaporation configuration because they are immersed in the additional liquid 4.

As illustrated in Figures 4A and 4B and according to one embodiment, the at least one plunger 122 is rotated to alternately pass from the first configuration to the second configuration. The plunger elements 122 have for example a disc shape and advantageously the discs comprise a portion with a porous surface 122a.

The disks are mounted on a drive shaft 123 so that they can be rotated in a transverse direction X1. The transverse direction X1 being preferably orthogonal to the main axis Y ₁ .

Due to the rotary movement of the movable element ₁₂ in the transverse direction discovered.

Thus the immersion of the discs in the liquid 2 leads to imbibition of the porous surfaces 122a. Said porous surfaces 122a soaked in and out of water are then advantageously stirred by a flow of air so as to accelerate the evaporation phase. This evaporation phase is amplified by the presence of the porous surfaces 122a of the disks which are added to the superficial surface 2a of the liquid 2.

Thus, evaporation is maintained by rotation of the plunger elements 122 in the liquid 2. The plunger elements 122 are exposed to a flow of air. For the condensation phase, the embodiment is identical but with cold water.

Several optional engine features will be described below. All of these optional features are compatible and combinable with each of the embodiments described above, in particular with each of the embodiments in which the divers are driven in translation or rotation.

Preferably, the hot source may be one of the following elements: an oven, a heat point, a heating resistance, a solar heat source, a recovery heat source, heat from thermal batteries .

The hot source being advantageously positioned all around and/or below the heating zone so as to allow the most efficient rise in temperature possible. The hot source can be obtained by exchanging the working liquid with new hot liquid in a closed circuit so as to maintain the operating pressure. The hot source can also be a coil inside the engine.

According to one embodiment, the enclosure 11 is a hollow cylinder extending along the main axis Y ₁ and the heating zone is located at a first end of the cylinder along the main axis Y ₁ . The enclosure 11 advantageously extends between a lower enclosure face 11b and an upper enclosure face 11a along the main axis Y ₁ . The mobile element being guided by its transmission axis.

Preferably, the hot source is distributed below the hollow cylinder, on the side of the first end and/or on the periphery of the cylinder.

Preferably, the cold source may be one of the following elements: a refrigerating system, a Peltier module, cooling fins, a radiator.

The cold source being advantageously positioned all around the cooling zone so as to allow the most efficient drop in temperature possible. The cold source may be a flow of cold liquid inside the engine coming from the outside and maintained at the operating pressure in a closed circuit.

According to one embodiment, the enclosure 11 is a hollow cylinder extending along the main axis Y ₁ and the cooling zone is located at a second end of the cylinder along the main axis Y ₁ .

Preferably, the cold source is distributed above the hollow cylinder, on the side of the second end and/or on the periphery of the cylinder.

The porous surface 122a is configured to retain liquid when the at least one plunger is submerged. This porous surface thus forms liquid retention cavities.

The porous surface 122a may be formed by the external material of the at least one plunger element 122. This material may be porous. For example, these could be materials such as wood, oxidized metal, paper, fabric, porous composite materials or a sponge material.

Alternatively, the porous surface can be formed by reliefs present on the plunger element. These reliefs can be formed for example by: streaks, grooves, strips, grids, sticks, or a lattice. For example, the grooves or grooves can extend in a direction parallel to the main axis Y ₁ perpendicular to the direction of translation if the movable element is translative or along radii of the disk if the movable element 12 is rotary. Note that the presence of reliefs can be combined with the use of a porous material.

According to one example, the porous surface of the at least one plunger element is entirely made of a porous material and takes the form of at least one of the following typologies of streaks, lamellae, grids, sticks, sponges or mesh.

This type of typology makes it possible to generate a set of voids capable of filling with fluid.

Wood could be used. Wood is advantageously porous in nature because its structure has fibers with voids with a spongy capacity. Wood is ideal for absorbing the fluid and is an unexpected material in an engine. Wood has the advantage of being an excellent thermal insulator which is suitable for good engine performance.

The formal typology of the plunger elements is such that it makes it possible to increase the soaked surface from which the liquid is taken while maintaining the same cavity volume.

A porous material or a porous surface may be understood as a solid material comprising a plurality of cavities capable of being filled with fluid.

According to one example, the motor comprises a plurality of plunger elements 122. These could be cylindrical tubes, preferably solid and alternately hollow. The plunger elements 122 can be spaced apart so as to create a space for the flow of gas mixture to pass through.

The plunger elements are advantageously rods whose diameter is less than or equal to the diameter of the displacer. Preferably, the diameter of a plunger element 122 is at least twice less, preferably at least four times less than the external diameter of the movable element 12. Along the main axis Y1, preferably the plunger elements will be dimensioned according to the material of which they are made so that the operating conditions of the engine do not cause them to bend.

According to one example, the plunger elements are hollow and preferably have openings to allow easier evacuation of the liquid 2.

According to one example, the plunger element 122 comprises a porous surface 122a. The plunger element 122 can be entirely covered with the porous surface 122a. The plunger element 122 can be covered with a fabric. The porous surface 122a can be made of one of the following materials: oxidized metal, wood, a composite material having cavities.

Advantageously, the plunger element can be made of natural or synthetic sponge or a similar material having a high capacity for absorbing liquids.

Preferably, the plunger element has a thermal conductivity less than or equal to 226 W · m ^–1 · K, preferably a thermal conductivity less than or equal to 100 W · m ^–1 · K ^-1 preferably less than or equal to 10 W · m ^–1 · K ^-1 , preferably less than or equal to 1 W · m ^–1 · K ^-1 . Thus, the plunger elements do not have the function of conducting heat. The plunger element 122 advantageously has a thermal conductivity less than or equal to 10 W · m ^–1 · K ^-1 so as not to disturb the evaporation and condensation phases with the gas mixture. The evaporation of the liquid would cool a plunger element 122 having a high thermal conductivity and would cool the heating liquid 2 during its reintegration into the liquid 2.

According to a particular embodiment, the plunger elements 122 are small identical elementary volumes.

According to a particular embodiment, the mobile element 12 and the plunger elements 122 form a single monolithic part.

According to a particular embodiment, the mobile element 12 is configured so as to alternately pass the gas from the heating space to the cooling space.

The invention is not limited to the embodiments previously described and extends to all the embodiments covered by the claims.

Numerical references
1/ Differential evaporation engine system
11/ pregnant
11a/ upper speaker face
11b/ lower enclosure face
112/ additional plunger elements
12/ mobile element
121a/ lower surface
121b/ upper surface
122/ plunger element
122a/ porous surface
123/ drive shaft
124/ ledge
14/ hot spring
15/ cold spring
2/ liquid
2a/ superficial surface
3/ gas mixture
4/ additional liquid
Y ₁ / Main axis
X ₁ / Transverse axis

Claims (21)

Differential evaporation engine system (1) comprising:

• an enclosure (11) having a cavity capable of containing a liquid (2), and a gas mixture (3),
• a hot source (14) configured to heat the liquid (2),
• a cold source (15) configured to cool the gas mixture (3),
• a movable element (12) configured to move inside the enclosure (11), the movable element (12) comprising at least one plunger element (122), the plunger element (122) being configured so to be at least partially immersed in the liquid (2) in a first configuration and alternatively in contact with the gas mixture (3) in a second configuration, the second configuration being different from the first configuration, in the second configuration the plunger element ( 122) being not immersed in the liquid (2) or being less immersed in the liquid (2) than in the first configuration,

the system (1) being characterized in that the at least one plunger element (122) has a porous surface (122a), the plunger element (122) being configured so that in the first configuration the porous surface (122a) impregnates a portion of the liquid (2) and that in the second configuration said portion of the liquid (2) evaporates at least partially on contact with the gas mixture (3). System (1) according to the preceding claim in which the enclosure is configured so that the liquid is overcome by the gas along a main axis (Y ₁ ) and that the movable element (12) moves by a translation movement according to the main axis (Y ₁ ). System (1) according to the preceding claim in which the plunger element (123) extends mainly in a direction parallel to the main axis Y ₁ . System (1) according to any one of the preceding claims in which the movable element (12) comprises a main portion (121) having a lower surface (121a) normal to the main axis (Y ₁ ) and the at least a plunger member (122) extends from the lower surface (121a), preferably the plunger member (122) having a rod shape. System (1) according to any one of the preceding claims in which the enclosure (11) comprises at least one additional plunger element (112) fixed relative to the enclosure (11) and having an additional porous surface portion (112a), the at least one additional plunger element (112) extending into the enclosure from a lower enclosure face (11b) of the enclosure (11) in a direction parallel to the main axis (Y ₁ ). System (1) according to any one of the preceding claims in which the main portion (121) of the movable element (12) defines a reservoir (121c) configured to contain an additional liquid (4) and the motor (1) is configured so that in the second configuration, the at least one additional plunger element (112) soaks up the additional liquid (4). System (1) according to any one of the preceding claims comprising a plurality of additional plunger elements (112). System (1) according to claim 1 in which the enclosure (11) is configured so that the liquid is overcome by the gas along a main axis (Y ₁ ) and the movable element (12) moves by a movement of rotation along a secondary axis (X ₁ ), orthogonal to the main axis (Y ₁ ). System (1) according to any one of the preceding claims in which the porous surface (122a) covers the entire surface of the at least one plunger element (122). System (1) according to any one of the preceding claims in which the motor comprises a plurality of plunger elements (122). System (1) according to the preceding claim in which the plunger elements (122) are spaced apart from each other so as to create a passage space for the gas in order to optimize the evaporation of the liquid soaked on the porous surface (122a) by contact with gas. System (1) according to the preceding claim in which the plunger elements are equidistant from each other. System (1) according to any one of the preceding claims in which at least one plunger element (122) is a rod and/or a cylinder. System (1) according to any one of the preceding claims in which the plunger element (122) has a hollow portion. System (1) according to any one of the preceding claims in which at least one plunger element (122) has at least one opening configured to allow circulation of the gas mixture (3) during the passage of the system (1) from one of the first configuration and the second configuration to the other of the first configuration and the second configuration. System (1) according to any one of the preceding claims in which the plunger element (122) is made of wood or a composite material or sponge or fabric. System (1) according to any one of the preceding claims in which the plunger element (122) is made of oxidized metal. System (1) according to any one of the preceding claims in which the plunger element (122) is made of a material having a thermal conductivity less than or equal to 10 W · m ^–1 · K ^-1 . System (1) according to any one of the preceding claims in which the porous surface of the at least one plunger element (122) is entirely made of a porous material and takes the shape of at least one of the following typologies ridges, strips, grids, sticks, sponges or mesh. System (1) according to any one of the preceding claims in which the cavity has a constant volume. System (1) according to any one of the preceding claims in which the cavity extends along a main axis (Y ₁ ) between a heating space and a cooling space so that the hot source (14) can heat the liquid (2) in the heating space by the side and/or lower faces and that the cold source can cool the gas mixture (3) in the cooling space.