EP0974802B1 - Heat exchange process for vaporizable fluid with recovering of energy and plant for using this process - Google Patents

Abstract

The method involves feeding the hot liquid into a container (20) under low pressure to vaporize it and cool the remaining liquid. The vapor is fed to a second container for extraction of the hot gas. The first and second containers are connected by two connecting circuits which are operated repetitively to feed the material to the second container.

Description

The present invention relates to an exchange method of energy in thermal recovery using a fluid vaporizable and involving cooling of said fluid in liquid phase with production of the same fluid at the state of vapor under pressure. It also concerns a installation designed for the implementation of this process.

The invention is particularly applicable advantageous for cooling a utility fluid by leaving an industrial unit where it was used, by example, to cool the machines and equipment, or on the contrary as a heating, possibly brought to the state of vapor in a boiler.

The vaporizable fluid in question is therefore fluent water, so that in the description detailed which will be given later, we will place ourselves for the essential in the typical case where the vaporizable fluid considered is water, or at least an aqueous vehicle. However, it must be admitted that the invention can find practical in many other situations whenever you want to cool a fluid, such as water, milk, fruit juices, chemical solutions, etc., being in the liquid state at hot temperature, or at least lukewarm, compared to a liquid temperature cold that one wishes to reach to reject it, or, more often to recirculate it at the entrance of the installation in which he warmed up.

The art prior to the present invention is found illustrated in particular by US patent documents 4,413 669 or GB 967 548. According to these documents, which are specifically in the context of water cooling of boiler, the hot fluid to be cooled is passed to through a series of chambers constituting evaporators in cascade, in which it cools in stages at gradually decreasing pressures, with vaporization partial. The different steam flows from successive stages are either extracted in parallel and combined to be reused, or grouped in cascade according to a circuit passing from one enclosure to another, in the opposite direction from hot fluid.

In all cases, the installation includes a final condenser, on the steam circuit, which is produced in the form of a surface heat exchanger, that is, hot steam and cold liquid water circulate on either side of a material wall (in general metallic for efficient exchanges through which the transfer takes place thermal.

In this type of installation, the present invention essentially aims to improve conditions thermodynamics and recovery efficiency of thermal energy, to simplify the construction of necessary materials, to reduce costs, both those related to design and installation than those related to operation and maintenance. It applies in particular that we have to recover for recycling the condensed fluid at the state of cooled liquid, or the fluid in gas phase, or both.

It also has the remarkable advantage of limiting the consumption of coolant required for operation of an industrial production unit, by compared to what we know about what is agreed to call cooling towers, in which a air current causes water vapor which is discharged to the atmosphere. Essentially, the invention then leads to discharge compressed vapor, found in the atmosphere therefore at a temperature above the temperature of 100 ° C. prevailing at ambient atmospheric pressure.

To do this, the invention plans to proceed without the least surface exchanger, for at least one last stage of a thermal energy recovery installation from a vaporizable fluid, causing a partial vaporization of the liquid to be cooled in a vacuum chamber where the vapor is compressed to a pressure vessel, and ensuring recovery of energy by mechanical coupling between two circuits connecting the two speakers which operate in turn repeatedly a mass transfer of the vapor phase fluid from the vacuum vessel to the pressure vessel.

Advantageously, the mechanical coupling is made by means of a reciprocating piston in limitation of two additional rooms, in which a suitable set of valves controls a double transfer of mass, alternately and repetitively, assuming the steam out of the first enclosure and driving it back return of the piston in the second enclosure.

A device according to the invention, allowing the implementation of the process which is the subject of the invention therefore comprises two enclosures where different pressures prevail. We admits in the first the fluid to be cooled, in phase liquid and hot. A fraction of it is vaporized, this which causes cooling. Steam is extracted from this first enclosure and transferred to the second enclosure where it is collected compressed. The organ of mechanical coupling ensuring the transfer is essentially consisting of a double-acting piston cylinder. The piston there separate two complementary rooms which communicate both with the two speakers. Valves admission and refoulement establish a transfer unidirectional from the first to the second enclosure at during the reciprocating movement of the piston.

In this way, the same movements of the piston help get depression in the first enclosure and ensure compression of the vapor in the second enclosure. Also, according to a characteristic important of the process of the invention, thermal energy is extracted from the hot liquid by mass transfer from the fluid in gas phase, which passes from the first enclosure to the second enclosure, in which this fluid, always in gas phase, is under pressure. The cooled liquid extract from the first enclosure. It can be recycled. We can also use the compressed steam available at the outlet from the second enclosure.

• les figures 1A et 1B illustrent schématiquement le fonctionnement d'un dispositif de mise en oeuvre du procédé selon l'invention, dans deux états de fonctionnement ;
• la figure 2A illustre schématiquement l'application d'un dispositif selon l'invention à une installation industrielle nécessitant le refroidissement d'une masse d'eau importante ;
• la figure 2B illustre schématiquement un condenseur utilisé dans une installation industrielle du type de celle décrite sur la figure 2A ;
• les figures 3A et 3B illustrent un exemple de réalisation pratique d'un dispositif selon l'invention, comprenant plusieurs étages ;
• et la figure 4 illustre un dispositif de ce type, selon mode de réalisation supplémentaire permettant d'obtenir un fluide en phase gazeuse sous pression élevée.

The invention will be better understood and other characteristics and advantages will appear on reading the description which follows with reference to the appended figures, among which:

• FIGS. 1A and 1B schematically illustrate the operation of a device for implementing the method according to the invention, in two operating states;
• FIG. 2A schematically illustrates the application of a device according to the invention to an industrial installation requiring the cooling of a large body of water;
• FIG. 2B schematically illustrates a condenser used in an industrial installation of the type described in FIG. 2A;
• Figures 3A and 3B illustrate a practical embodiment of a device according to the invention, comprising several stages;
• and FIG. 4 illustrates a device of this type, according to an additional embodiment making it possible to obtain a fluid in the gas phase under high pressure.

The process according to the invention will now be described with reference to Figures 1A and 1B. These figures schematically illustrate an exemplary embodiment of a device ensuring the implementation of this process.

The device 1 essentially comprises three parts: two tanks 2 and 3, respectively delimiting one first chamber called vacuum 20 and a second chamber said to be under pressure 30, due to the fact that in operation, maintains the enclosure 20 under vacuum relative to the second enclosure 30, and a fluid transfer member 4 allowing the two speakers 20 and 30 to communicate according to modalities which will be explained below.

In practice, we will understand that by this, we achieve a mechanical coupling between two circuits which pass the fluid in the vapor phase of the steam generating chamber to the second enclosure for compressing this vapor, said transfers taking place repeatedly role as they are commanded by the movement of back-and-forth translation of a double-acting piston in a cylinder in which it delimits two chambers complementary respectively belonging to each of the two circuits.

In the enclosure 20 of the tank 2, we admit at the top, by a pipe 21, a hot fluid in the liquid state, that to fix the ideas, we will assume to be hot water, or at least lukewarm, from a downstream installation not shown. A pump 210 ensures the circulation of the liquid in the supply line 21. This opens, inside the enclosure 20 by a nozzle spray 22 or similar boom. Water vaporizes partially in the depressed atmosphere. Water no vaporized 23 meets in the bottom of the enclosure 20, however that part of the mass of water injected into found in the form of water vapor 23 '.

The fraction of water 23 not vaporized 23 can be recovered, cooled due to the relaxation undergone, in the bottom of the enclosure 20. It is extracted therefrom either for the reuse in the downstream installation where it heats up and re-inject it through the input circuit 21, i.e. for the reject, but at low temperature. The evacuation pipe 26 is symbolized by a simple solid line in the figures. There is on this pipe 26 an extraction system 6, illustrated by a pump 60 and a non-return valve 61.

As indicated, enclosure 30 of the second tank 3 communicates with the enclosure 20 of the first tank 2, by means of mechanical coupling illustrated by a cylinder 40 in which a double piston effect 41 moves in translation alternately in one direction and in the other, completed by a set of pipes allowing a double mass transfer from the first enclosure 20 to the second enclosure 30.

The piston 41 divides, at any time during its stroke, the internal enclosure of the cylinder 40 in two chambers complementary, respectively an upper room 400 and a lower room 401. Upper room 400 communicates with the upper part of the first enclosure 20, by a first line 24 and an inlet valve 42, disposed at the inlet of the upper chamber 400, and with the upper part of the enclosure 30, by a second pipe 31 and a valve exhaust 43 at the outlet of the upper chamber 400. Similarly, the lower chamber 401 communicates with the lower part of the first enclosure 20, by a third pipe 25 and a inlet valve 44, arranged at the inlet of the lower chamber 401, and with the lower part of the enclosure 30, by a fourth line 32 and an exhaust valve 45 in exit from the lower chamber 401. The set of intake valves and exhaust requires fluid transfer unidirectional, from the first enclosure 20 to the second enclosure 30, respectively through each chambers of cylinder 40.

The piston 41 is driven by machinery 5, comprising a motor (not shown) driving in turn a flywheel 50. The flywheel 50 is mechanically coupled to the piston 41 by a conventional connecting rod assembly 52 and crank 51, connected by an axis 510, so that the piston 41 performs a repetitive displacement of translations backward and forwardward alternatives inside of cylinder 40.

In FIG. 1A, a phase of the cycle has been represented during which the piston 41 is pulled down. The valves 42 and 45 are open and valves 43 and 44 closed. In this state, the water vapor 23 'produced under reduced pressure, is sucked by the piston 41 of the enclosure 20 to the upper chamber 400, via line 24 and the valve intake 42 which contributes to depression in enclosure 20. At the same time, the contents of the room bass 401 is driven back to enclosure 30 by the movement of the piston down, via the exhaust valve 45 and the conduct 32. These are, as will be described below, water vapor sucked in the previous cycle, which is thus expelled compressed to the pressure vessel. Indeed, the inlet valve 44 being closed, the movement of the piston 41 is accompanied by compression in the lower chamber 401.

In FIG. 1B, a phase of the cycle has been represented for which the piston 41 is pushed up, the valves 43 and 44 open and valves 42 and 45 closed. he this is a fully dual state from that described opposite of Figure 1B. The process and the effects obtained are quite similar to those just described, at the only exception is that upper house 400 plays the role of the lower house 401, and vice versa. It follows that it is lines 25 and 31 which become active in mass transfer from the first to the second enclosure.

Line 25 opens into enclosure 20 at a suitable level so as not to suck the liquid at the bottom of tank 23. In addition, the shape of its mouth is provided for not to receive a direct flow of liquid, by sprinkling. he is possible, to do this, to give it a form of whistle, the bevelled part of which faces downwards, as suggested by Figures 1A and 1B, or a form similar.

The water vapor 23 '(or more generally the fluid in gas phase) extracted from the enclosure 20 is transferred to enclosure 30. It is found in this pregnant, still in gaseous form, but at pressure higher than the pressure in enclosure 20. The enclosure 30 opens onto a steam outlet pipe 33. This advantageously leads into the lower zone of this enclosure, near the bottom where condensates are collected potential. A drain 34 makes it possible to remove these condensates.

Depending on the specific application, 23 "water vapor, present in enclosure 30, can either be ejected at atmospheric pressure, if outlet line 33 is open, either available under pressure for use later (upstream installation not shown).

We will now describe an example of installation industrial using a device according to the invention for water cooling, with reference to FIGS. 2A and 2B.

The industrial installation shown in FIG. 2A essentially comprises three parts: a boiler room Ch producing steam, a unit U in which this steam is used and a device 1 according to the invention, such as that of FIGS. 1A and 1B. FIG. 2A shows only the elements necessary for a good understanding of the invention. The elements common to the previous figures have the same references and will only be described again as necessary.

The steam is transmitted from the boiler room Ch to the unit U by one or more supply pipes Ce and the condensates are returned to the boiler room Ch through one or more recycling pipes Cs . Unit U includes a number of machines or devices using the steam produced. In the example described, the steam supplies a battery of condensers C ₁ to C _n , arranged in cascade, n being an arbitrary number which depends on the specific application. As an example of an application, mention may be made of the successive stages of concentration of whey as a by-product of a cheese dairy.

Figure 2B schematically illustrates the structure of such a condenser, referenced 7. It is a heat exchanger surface, tube type. It receives steam through a inlet pipe 70 and the condensates are returned by a pipe 71. Cold water is introduced into the tubular circuit via an inlet pipe 73, there heats by heat exchange with the vapor present in the condenser, and comes out through line 72.

In the example illustrated by FIG. 2A, the condensers C ₁ to C _n are all similar to the condenser 7. To fix the ideas, we will consider that the temperature of the vapor in the pipe Ce (entering the condenser C ₁ ) is at a temperature of 75 ° C, and that it enters the last condenser, for example the fourth if n = 4, at a temperature of 40 ° C. Given that the heat exchanges are not perfect, the water leaving this condenser via line 21 is typically at a temperature of the order of 40 ° C.

It must be cooled, whether recycled or no (discharge into the river for example). In an installation according to known art, a tower of cooling, with the disadvantages of this type previously recalled. The tower of cooling, or any similar installation, is advantageously replaced by a device 1 conforming to the invention, as illustrated in Figure 2A.

The operation of this device 1 is identical to what has been described with reference to FIGS. 1A and 1B, and it is unnecessary to repeat it in detail. The hot water, at the outlet of the condenser bank, C ₁ to C _n , is introduced into the enclosure 20 of the tank 2, where it is vaporized at 22. The remaining liquid part 23, at low temperature, is returned to the condenser bank via line 26, fitted with the vacuum extraction device 6 (FIGS. 1A and 1B: pump 60 and non-return valve 61). It traverses these condensers in series in the opposite direction to the supply steam.

The part of the sprayed water (at 22) transforming into water vapor 23 'is transferred into the enclosure 30 of the second tank 3, under a pressure higher than the pressure prevailing in the enclosure 20. Its temperature also rises. The compressed steam 23 "can then be recycled through line 33 and re-injected at the inlet of the condenser bank, C ₁ to C _n , rather than being discharged to the atmosphere.

In compensation for losses linked to vaporization, water is added to the recirculation circuit (line 26). This extra water is provided by an additional pipe 27 connected to a network of distribution of water at low temperature. In addition, we have shows in the figure a motor 8, for example a electric motor, which controls the machinery 5 piston 41.

To fix ideas, and without limiting it in whatever the scope of the invention we're going to give now a numerical example relating to an installation typical water cooling.

It is assumed that the flow of water entering the tank 2 via line 21 is 30,000 1 / h and its temperature is 40 ° C. By the process of vaporization by expansion and compression of the steam produced, in cooperation with the action of the fluid transfer member under coupling mechanical 4, which passes the vapor from the enclosure under vacuum 20, operating in partial vaporization of water and production of cold, at pressure enclosure 30 operating in vapor compression, one can obtain a cooling of the incoming liquid which is such that the temperature of the liquid 23, recovered at the bottom of the enclosure 20 and recycled through line 26, typically of the order 15 ° C. With an atmospheric cooling tower, we would not go below 20 to 25 ° C.

The pressure prevailing in the enclosure 20 is very below atmospheric pressure, i.e. 0.017 atm (i.e. 1.72 kPa) for the above conditions. In these same conditions, taking into account the difference of temperature obtained, the quantity of calories released is 30,000 × (40-15) = 750,000 kcal (or 179,135 kJ). The enthalpy of water vapor at 15 ° C being equal to 588.8 kcal / kg, the amount of steam produced per hour is equal to (750,000 / 588.8), or 1,273 kg / h. It is performed equivalent water make-up in the return circuit (line 26).

The steam in the enclosure 30 is under a pressure close to atmospheric pressure, therefore much greater than the pressure prevailing in the enclosure 20. In addition, the temperature of the steam 23 "in the enclosure 30 rises and can reach values typically between 75 and 100 ° C. This 23 "vapor can therefore be recycled by re-injection at the inlet of the unit U (line Ce), via line 33. It is assumed , in fact, that the boiler Ch produces steam at a temperature of 75 ° C, under a pressure of 0.39 atm (or 39.5 kPa). After an initialization period, that is to say when the "cruising" regime is reached, with the losses nearly compensated by a production of steam by the boiler Ch , the steam recovered may be sufficient to supply the unit U .

The tanks 2 and 3 are produced according to the usual boilermaking techniques in the form of ferrules cylindrical closed by domed bottoms and lids. The diameter of each enclosure is 480 mm and height 1.5 m. The diameter of the pipes 24, 25, 31 and 32 is typically 200 mm. The tanks, 2 and 3, must be waterproof and withstand operating pressures. The diameter of the enclosure of the piston 41, and therefore of the enclosure of the cylinder 40, is 630 mm, and the height of this enclosure is 610 mm. The piston 41 can be animated at a speed of 2 revolutions per second by a drive motor 8 capable of developing a power of the order of 100 kW. A standard 115 kW electric motor can be used.

Device 1, as it was more particularly described with reference to FIGS. 1A and 1B, suitable for low or medium installations power. The word "power" is heard here in terms of water flow to be treated per unit of time, or more generally useful fluid circulating in the circuit primary.

Given that the specific volume of the vapor of water under low pressure is very important it's necessary to obtain a fluid transfer rate by organ 4 (Figures 1A and 1B) also important. This can naturally be obtained, at least theoretically, by increasing the dimensions of the device 1, namely the tank capacities, pipe diameters, cylinder volumes, etc.

However, this solution quickly becomes impractical, in particular with regard to the transfer members, and more particularly the moving parts that are valves and pistons. Also, in the mode of preferred embodiment, a large nominal flow can be obtained by providing for a succession of transfer organs (cylinders and pistons), arranged in parallel. An example practice of such an embodiment is illustrated by the Figures 3A and 3B, in side and front view, respectively.

To fix the ideas, it was assumed that the device, now referenced 1 ′, included two rows of four transfer members. The cylinders of each row are marked a to d , and the two rows are marked arbitrarily, d and g , for "right" and "left". The same conventions have been adopted for the other elements of the device 1 ′ which relate to one or the other of the eight transfer members. In addition, the elements common to the previous figures have the same references and they will be described again only as necessary.

In the example described, it has been assumed that the hot water, coming from the industrial unit (FIG. 2A: U ), was stored in the enclosure 90 of an intermediate tank 9 and injected into the device proper by a system comprising a pump 210 and a non-return valve 211, and the pipe 21.

According to a first characteristic of this mode of realization, the first tank is divided into two: tanks 2a and 2b, delimiting the enclosures 20a and 20b. More specifies, in the illustrated configuration, the tank 2a is arranged vertically and it plays the role of tank 2 of the previously described device. Line 21 enters the enclosure and it comprises a spray nozzle 22, as before also.

Part of the hot water injected turns into vapor phase, 23 ', while the rest of the water, 23, which is cooled, fills the bottom of the enclosure 20a of the tank 2a, to be rejected or recycled by the usual circuit: line 26, pump 60 and non-return valve 61. According to applications, a cold water top-up is provided or not driving 27.

The tank 2b is in the form of a cylinder horizontal opening into the enclosure 20a. 20b speaker the tank 2b can have the same diameter as that of the enclosure 20a of the tank 2a. In the same way, the tank 3 is advantageously arranged horizontally, parallel in tank 2b. In reality, the tank 2b constitutes an extension of tank 2a, which allows easier coupling of tanks "primary" and "secondary", taking into account the structure particular of fluid transfer members.

Indeed, on either side of these two parallel tanks, 2b and 3, there are two rows of transfer members, with their associated pipes. Thus, in FIG. 3A, which shows the "straight" part of the device 1 ′, four transfer elements have been shown, referenced 4 ad to 4 dd . FIG. 3B, in front view, shows the two extreme transfer members, belonging to the right and left rows, that is to say the members 4dd and 4 dg .

Each of these transfer members, 4 ad to 4 dg , is quite similar to the single transfer member in FIGS. 1A and 2A. Only the configuration of the supply and extraction pipes is adapted to the particular arrangement in the space of the tanks 2b and 3, on the one hand, and to the location of the transfer members, 4 ad to 4 dg, relative to these tanks, on the other hand. FIG. 3B illustrates the pipes associated with the transfer members 4 dd and 4 dg , namely the pipes 24 dd and 25 dd making the enclosure 20b communicate with the cylinder of the transfer member 4 dd , the pipes 31 dd and 32 dd causing the enclosure 30 to communicate with the cylinder of this same transfer member 4 dd, the pipes 24 dg and 25 dg making the enclosure 20b communicate with the cylinder of the transfer member 4 dg , and the pipes 31 dg and 32 dg making the enclosure 30 communicate with the cylinder of this same transfer member 4 dg .

We find an identical organization for the other floors (for example figure 3A: 4 ad to 4 cd ).

As before, these transfer members, 4 ad to 4 dg , include a double-acting cylinder and piston, as well as two pairs of intake and exhaust valves, one pair for the upper chamber and the other for the chamber. lower. In order not to overload the drawing, these elements have not been referenced individually.

The pistons are driven by a four-stage machinery (actually two times four stages), 5 ad to 5 dg , comprising "rod-crank" systems (not referenced explicitly) and flywheels, 53 ad to 53 dg . A single motor 8 drives the assembly, for example and in a conventional manner per se, by means of belts, alternately arranged to the right and to the left of the device 1 ": belts on the right 55 and 57, and on the left 56 and 58. The flywheels, 53 ad to 53 dg , are arranged in pairs on common trees, 500 a to 500 d . These trees rotate in pairs of bearings, right and left, 53 ad to 53 dg . The bearings, 53 ad to 53 dg , and the motor 8 are fixed to a lower support Sup of the device 1 ", which can itself be fixed to the ground by any suitable means (not shown).

To obtain balanced operation of the 1 "device, in particular to avoid vibrations and it is advantageous to time-shift the positions of the pistons in the cylinders, in pairs, of a on the other hand, and in stages of the same row, as suggests in Figures 3A and 3B.

The overall operation of the device 1 ", according to the embodiment which has just been described, is quite similar to that of the device 1, as explained with reference to FIGS. 1A to 1B, and it is unnecessary to rewrite it in detail. The essential advantage of the configuration of the 1 "device, due to the parallel connection of several transfer members, is to be able to process a higher useful fluid flow rate, without being obliged to inconsiderately increase the dimensions of the constituent elements, at least those of the transfer members, 4ad to 4 dg , of the piping, and of the parts of the machinery, 5 ad to 5 dg , actuating the pistons.

For some applications, it is necessary to have high pressure steam. While maintaining the basic architecture of the device in FIGS. 2A and 2B, it is possible to obtain such a result.

To do this, according to one embodiment additional, we partition the device into two stages in cascade, and more particularly the "secondary" tank receiving steam under pressure.

Figure 4 illustrates, in side view, such a mode of production. The elements common to the previous figures have the same references and will only be described again as needed.

The device, now referenced 1 ", comprises two parts, or cascade compression stages: e _I and e _II . The stage e _I comprises all the elements of the device 1 ′, with the exception that in the example illustrated in FIG. 4, only three stages of transfer members per row have been provided, for example the members 4 ad to 4 cd , for the right-hand side, except for this operation of this stage e _I is strictly identical to that of the device 1 'in FIGS. 2A and 2B.

According to another characteristic of this mode of realization, the tank of the "secondary" circuit is also divided into two tanks, referenced 3a and 3b.

The vaporized water 23 'is transferred into the enclosure 20b of the tank 2b towards the enclosure 30a of this tank 3a, under a higher pressure than that prevailing in enclosure 20a.

According to yet another characteristic of this embodiment, the last stage of transfer members, that is to say the pair of right and left members, of which only the right member 4'd is visible in the figure 4, has a special role. It connects the enclosure 30a of the tank 3a with the enclosure 30b of the tank 3b. The transfer of steam 23 "a takes place again with an increase in the compression ratio (steam 23" b). Also, the upper and lower chambers (not shown) of the cylinders of the pair of transfer members of the last stage e _II , communicate with the enclosure 30a via two conduits, 24'd and 25'd, respectively . Similarly, these upper and lower chambers communicate with the enclosure 30b via two pipes, 31'd and 32'd, respectively.

The driving machinery is strictly identical to that described with reference to FIGS. 3A and 3B.

It is still possible to generalize the operation of the device 1 ", by adding one or more several additional supercharging stages, i.e. by providing three or more "secondary" tanks, and not two as illustrated in figure 4. There is between each tank a transfer device or a pair of transfer devices transfer. On each stage, the vapor pressure obtained increases, as does its temperature.

Considering that steam even after just one transfer, is under a much higher pressure than that prevailing in the enclosures of the "primary" circuit, by example in enclosure 23b, it is generally unnecessary to provide several stages of transfer devices, because the specific volume of steam has greatly decreased. According to steam flow to be obtained, a single transfer device may also be sufficient, instead of a pair.

On reading the above, we can easily see that the invention does achieve the goals it has set for itself.

It should be clear, however, that the invention is not not limited to only examples of achievements explicitly described, in particular in relation to FIGS. 1A to 4. In in particular, the numerical values have only been specified to fix ideas. They essentially depend on the precise application targeted. Likewise, where there are several, the number of transfer organs is not limited to two pairs of four organs in parallel. This number basically depends on the instantaneous amount of fluid treat. Although the paired configuration is advantageous, we can also adopt another configuration, for example online.

It should also be clear that, although particularly suitable for cooling and recycling of hot or lukewarm water, from industrial installations (nuclear power plant, etc.), the invention cannot be confined to this one type applications. The invention finds application every time that it involves cooling a fluid in liquid form and recover stored calories, with or without recycling of this fluid, and possible use of the steam generated according to the process, in a more or less form compressed, depending on the type of device used. AT As non-exhaustive examples, we can cite the cooling of milk, various fruit juices, chemical solutions, cooling water from a hot spring to produce steam, etc.

Finally, although particularly suitable for large power installations, the process of the invention is entirely compatible with installations of medium or small powers, even with domestic installations and / or appliances.

Claims (11)

1. Method for recuperation of thermal energy from a fluid which can be vaporised, according to which, in at least one implementation stage:

   the said fluid is admitted in a hot liquid state into a first, reduced-pressure enclosure (20) in which it is vaporised partially, giving rise to cooling of the non-vaporised fraction of fluid (23) which is recuperated in a liquid phase; and

   the vapour produced in the said first enclosure is admitted by being compressed into a second pressurised enclosure (30), from which it is extracted in a hot gaseous phase;

   characterised in that the transfer of the vapour from the first enclosure to the second enclosure is assured by two mechanically coupled circuits, by passing respectively via two complementary chambers which are separated by a piston which is driven in alternating translation displacement, these two circuits thus being operative alternately repetitively, in order to suck the steam out of the first enclosure and deliver it into the said second enclosure (30).
2. Method according to claim 1, characterised in that the said fluid which can be vaporised is a utility fluid obtained from an industrial unit (U) in which it has undergone heating and in which the said cooled fluid in a liquid phase (23) is returned via a cold fluid recycling circuit (26, 6) into the said industrial unit (U), and is reintroduced into the said first enclosure (20) after it has been heated.
3. Method according to claim 2, characterised in that it comprises an additional step which consists of introducing an additional quantity of the said utility fluid which can be vaporised into the said cold fluid circuit, with a mass equal to the said fraction of vaporised fluid transferred from the said first enclosure into the said second enclosure, such as to compensate for this quantity of fluid transferred.
4. Method according to claim 2 or claim 3, characterised in that the said industrial unit (U) comprising a generator (Ch) for fluid in a gaseous phase, with a predetermined temperature and pressure, and means (C₁-C_n) for thermal exchange between this vapour and a circuit (21-26) in which the said utility fluid to be cooled circulates, the said compressed fluid in a gaseous phase (23") which is present in the said second enclosure (30) is returned (33) towards the industrial unit (U) and the said means (C₁-C_n) for exchange.
5. Method according to any one of claims 1 to 4, characterised in that it comprises at least one additional step which consists of transferring the said compressed fluid in a gaseous phase (23") from the said second enclosure (30a) to an additional enclosure (30b), by additional mechanical coupling means (4'd) which suck the compressed fluid in a gaseous phase (23"a) from the second enclosure (30a) and deliver it with an additional level of compression into the said additional enclosure (30b).
6. Method according to any one of the preceding claims, characterised in that the said utility fluid which can be vaporised is water.
7. Installation for implementation of the method according to any one of the preceding claims, characterised in that it comprises at least:

   a first enclosure (20) which is provided in an upper area with a pipe (21) to supply fluid to be cooled, with means (22) for vaporisation of the fluid admitted, and, in a lower area, with a pipe (26) for extraction of the said cooled fluid in a liquid phase (23);

   a second enclosure (30) which is provided with a pipe (33) for discharge of the said compressed fluid in a gaseous phase (23"); and

   means (4) for transfer of the vapour produced (23') under compression in the second enclosure repetitively and alternately, by passing via two complementary chambers (400, 401) on both sides of a single piston (41) in alternating displacement, the said chambers being equipped with suction valves in communication with the first enclosure (20) and delivery valves in communication with the second enclosure (30).
8. Installation according to claim 7, characterised in that the said first enclosure is double and consists of a vertical enclosure (20a) which is provided with the said pipes (21) for introduction of the said utility fluid to be cooled and for discharge (26) of the said cooled fluid in a liquid phase (23), and with a horizontal enclosure (20b) which opens at one of its ends into the said vertical enclosure (20a), in that the said second enclosure (30) which contains the said compressed fluid in a gaseous phase (23") is also horizontal, and in that a plurality of means (4ad-4dg) for transfer which connect the said horizontal enclosures (20b, 30) are provided.
9. Installation according to claim 7 or claim 8, characterised in that the said means (4) for transfer comprise a cylinder (40) with a double-effect piston (41) which performs outward and return movements inside the said cylinder (40), the said piston (41) defining inside the said cylinder (40) a high chamber (400) and a low chamber (401), in that the said high (400) and low (401) chambers each communicate with the said first (20) and second (30) enclosures by means of a pair of pipes (24-25, 31-32) which open into these enclosures (20, 30) and in that these chambers (400, 401) are provided with intake valves (42, 44) on the said pipes (24, 25) which open into the first enclosure (20) and outlet valves (43, 45) on the said pipes (31-32) which open into the second enclosure (30), such as to permit the said transfer of vaporised fluid (23') from the first enclosure (20) towards the second enclosure (30) with the said predetermined level of compression.
10. Installation according to claim 9, characterised in that each of the said double-effect pistons (41) is moved by a connecting rod and crank system (51-52) which is driven by a variable-speed motor (8).
11. Installation according to any one of claims 7 to 10, characterised in that, the said second enclosure (30a) being closed, it comprises at least one additional enclosure (30b) and additional means for transfer (4'd) which couple the second enclosure (30a) mechanically to the said additional enclosure (30b), such as to transfer the said compressed fluid in a gaseous phase (23"a) from the second enclosure (30a) to the said additional enclosure (30b), with a higher level of compression.

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