FR3122726A1 - LOW MAINTENANCE HEAT EXCHANGE DEVICE - Google Patents

Abstract

Heat exchange device for modifying the temperature of at least a first fluid, comprising at least one heat transfer element (8) and at least one circulation element (2) for a first fluid configured to be in contact with the heat transfer element (8), said circulation element (2) for a first fluid being made of a flexible material defining a circulation channel (4) for the first fluid between an inlet (5) and an outlet ( 6), said circulation element (2) of the first fluid being configured to be removable. Figure for abstract: 2

Description

LOW MAINTENANCE HEAT EXCHANGE DEVICE

TECHNICAL AREA AND PRIOR ART

The present invention relates to a heat exchange device for fluid requiring reduced maintenance.

In the food industry, we want to be able to heat or cool fluids quickly, for example for an on-demand service.

For example, drinking establishments generally use a beer tap that allows beer to be served from a keg. The dispenser incorporates a beer cooling system which generally consists of circulating the beer in a metal tube, for example in the form of a serpentine, surrounded by ice water. The beer in contact with the wall of the cooled tube cools before leaving the dispenser.

This installation requires regular, meticulous and costly maintenance. Indeed, it is necessary to regularly clean the inside of the tube in which the beer circulates to ensure health safety and avoid modifying the taste of the beer.

However, such maintenance is long and requires a certain skill.

The same problem arises for heating food liquids.

In addition, tube cleaning is required when changing the fluid to be cooled or heated.

The problem can also arise to heat or cool other fluids which would not be intended to be ingested, when one wishes to change the fluid to be heated or cooled and to ensure that there is no residue of the fluid previous in the tube. This cleaning is all the more complex as the tube has a complex shape, for example a serpentine shape.

It is therefore an object of the present invention to provide a heat exchange device for a simplified maintenance fluid.

The object stated above is achieved by a heat exchange device for a fluid comprising at least one heat transfer element and at least one fluid circulation element configured to be in contact with the heat transfer element, said fluid circulation element comprising a fluid circulation channel between an inlet and an outlet, said fluid circulation element being removably mounted in the heat exchange device. The fluid exchanges heat with the heat transfer element through the walls of the circulation element. Thus the fluid can be brought to a desired temperature by heat exchange with the heat transfer element.

Since the fluid circulation element is removable, it can be removed during maintenance and can be easily cleaned. It may be considered to replace it with a new circulation element.

Preferably, the fluid circulation element is made of a flexible material delimiting the fluid circulation channel. The fluid circulation element is for example produced by a pocket formed by two sheets of polymer material welded together and delimiting the circulation channel between them.

The circulation element is such that it is removable and can be easily removed, replaced or replaced in the heat exchange device.

In the case of a flexible pocket, the cost of manufacturing such a circulation element is relatively low, then it can be replaced instead of cleaned. Maintenance of the temperature-setting device is thus further simplified. There is no longer any risk of insufficient cleaning and/or fluid residue. In addition, the time required for maintenance is reduced.

In addition, in the case of a flexible bag, the pressurized fluid circulating in the bag deforms the walls which come into contact with the heat transfer element(s), ensuring good heat exchange.

The flexible pocket is then a three-dimensional exchanger component made from two-dimensional films by causing the treated fluid to circulate under pressure in the exchanger component, which deforms it transversely, and makes it possible to obtain thermal contact on the exchange plates.

For example, the sheets are made of a polymer material, of metal or of a polymer/metal composite.

The heat transfer element may comprise a plate in which is provided at least one channel for the circulation of a coolant or comprise a solid plate ensuring the conduction of heat between two fluid circulation elements.

One of the objects of the present application is a heat exchange device for modifying the temperature of at least one first fluid, comprising at least one heat transfer element and at least one circulation element for a first fluid configured to be in contact with the heat transfer element, the element for circulation of a first fluid comprising a channel for circulation of the first fluid between an inlet and an outlet, of which at least one wall is intended to be in contact with the heat transfer element, said circulation element being removably mounted, the channel inlet having a first connector configured to connect the circulation element to a first circuit connected to a source of first fluid and the channel outlet comprising a second connector configured to connect the circulation element of a first fluid to a second circuit connected to means for using the first fluid, so that the circulation element of a first fluid is removable.

Very advantageously, the element for circulating a first fluid is made of a flexible material defining a channel for circulating the first fluid between an inlet and an outlet, said element for circulating the first fluid being configured to deform when the first fluid under pressure circulates in the circulation channel and to come into contact with the at least one heat transfer element, so that the first fluid exchanges heat with the heat transfer element through the flexible material.

For example, the circulation element of the first fluid comprises two superimposed sheets, each of the sheets being made of polymer, of metal or of a composite polymer and metal material and the circulation channel is formed by welds between the two sheets. The polymer can be polyethylene and the metal can be aluminum.

In an advantageous example, the heat transfer element comprises at least one circulation channel for a coolant.

The heat transfer element may include electrical heating means.

In an exemplary embodiment, the heat exchange device comprises at least two heat transfer elements defining between them a housing configured to receive the circulation element of a first fluid.

Preferably, the spacing between the two heat transfer elements is such that the circulation element of a first fluid in its deformed state is in contact with the two heat transfer elements.

The heat exchange device may comprise several circulation elements of a first fluid configured to be supplied in parallel or in series and several housings, each receiving a circulation element of a first fluid.

In another exemplary embodiment, the heat exchange device comprises at least one element for circulation of a second fluid arranged on the opposite side of the heat transfer element with respect to the element for circulation of a first fluid so that there is heat transfer between the first fluid and the second fluid.

The second fluid circulation element is advantageously made of a flexible material defining a second fluid circulation channel between an inlet and an outlet, said second fluid circulation element being configured to deform when the second fluid under pressure circulates in the circulation channel.

Preferably, the heat exchange device comprises thermally insulating outer walls.

Another object of the application is a system for modifying the temperature of at least one first fluid comprising, at least one transfer device according to the invention, a source of first fluid under pressure at a first temperature connected to the inlet of an element for circulating a first fluid, a source of coolant connected to a heat transfer element, and means for using the first fluid at a second temperature different from the first temperature.

For example, the system is an on-demand beer dispensing system, the first fluid being beer.

Another object of the present application is a system for modifying the temperature of at least one first fluid comprising, at least one transfer device according to the invention, comprising a source of a first fluid under pressure connected to the circulation element into a first fluid and a source of a second pressurized fluid connected to the circulation element in a second fluid

Another object of the present application is a method of using a system according to the invention, comprising:
-the placement of a circulation element for a first fluid between two heat transfer elements,
-the connection of the circulation element of a first fluid to the supply source of a first pressurized fluid and to the means for using the fluid at the second temperature,
- the sampling of the first fluid at the second temperature after circulation of the first fluid in the circulation element of a first fluid,
- the disconnection of the circulation element of a first fluid and the withdrawal thereof,
-the connection of a circulation element of a first new fluid to the supply source of a first fluid and to the means of use of the first fluid.

Another object of the present application is a method of using a system according to the invention comprising:
-the placement of a circulation element for a first fluid and a circulation element for a second fluid on either side of the heat transfer element,
-the connection of the circulation element of a first fluid to the supply source of a first pressurized fluid and to the means for using the fluid at the second temperature, and the connection of the circulation element of a second fluid to the supply source of a second pressurized fluid and to the means of second use,
- the sampling of the first fluid at the second temperature after circulation of the first fluid in the circulation element of a first fluid,
- the disconnection of the circulation element of a first fluid and/or of the circulation element of a second fluid and withdrawal of one or the other or both,
-the connection of a circulation element of a first new fluid to the supply source of a first fluid and to the means of use of the first fluid, and/or the connection of a circulation element of a second the new fluid to the supply source of a second fluid and to the means for using the second fluid.

The present invention will be better understood on the basis of the following description and the appended drawings in which:

is a flat diagrammatic representation of an example of a fluid circulation element according to the invention.

is a schematic representation of an example of a heat exchange device implementing a heat circulation element .

is a schematic representation of an example of a heat exchange device implementing several heat circulation elements , connected together in parallel.

is a schematic representation of an example of a heat exchange system implementing the device of the .

is a schematic representation of another example of a heat exchange device implementing several heat circulation elements .

DETAILED DISCUSSION OF PARTICULAR EMBODIMENTS

The invention applies to the heating or cooling of fluids, in particular liquids, such as water, milk, beer, and liquids whose viscosity can reach 100 times the viscosity of water, i.e. order of 0.1 Pa.s. The flow rates and diameters are adapted to the viscosity of the liquid. The fluid may or may not be a food fluid.

On the , one can see a top view of an exemplary embodiment of a fluid circulation element 2 which is formed by a flexible element, which will also be referred to as a “pocket” in the remainder of the description.

The fluid circulation element 2 comprises two sheets of flexible material fixed to one another so as to delimit between them a channel 4 for the circulation of the fluid. The channel has an inlet 5 and an outlet 6. The inlet 5 is intended to be connected to a source of pressurized fluid and the outlet 6 is intended to be connected for example to a fluid delivery valve. Alternatively, the pocket 2 is formed by folding a sheet on itself.

The fluid circulation element 2 has for example a rectangular shape, the inlet 5 opening into a side edge of the circulation element and the outlet 6 opening into the same side edge or another side edge. As a variant, the inlet and the outlet open into the same edge or adjacent edges. Furthermore, the shape of the pocket is not limiting and a circular shape or any other is possible.

The channel 4 preferably has a shape maximizing the path of the fluid between the inlet 5 and the outlet 6 and the exchange surface, which increases the heat exchange between the fluid and a heat transfer element which will be described below. -below. The shape of the channel is chosen according to the fluid which circulates in it, in particular its viscosity and its thermal conductivity, according to the flow to be transferred, in order to optimize the pressure drops, and the exchange coefficient.

The shape of the channel is chosen so that it covers the maximum surface of the pocket. For example, the channel can run in a chevron or zigzag pattern between the inlet and the outlet.

The pocket is made of a sufficiently flexible material such that, when a fluid under pressure circulates in the channel, the material deforms and then delimits a channel with an approximately rectangular section, the faces of the channel resting on the flat surface of the elements of heat exchange. The ratio between the width and the length of the rectangular section is advantageously between 1 and 2.

The material of the bag is adapted to the fluid intended to circulate in it, so that it is inert with respect to it. In the case of a food fluid, the sheets are made of polymer material suitable for contact with food or of a composite material, for example polymer-metal, for example aluminum, to improve the mechanical strength of the element and/or block the diffusion of gases, for example oxygen.

The material is also chosen according to the temperature at which the fluid will be heated or cooled.

The flexible pocket can be made of polymer material, for example polyethylene or polyvinyl chloride, for example 20 μm thick or with aluminum sheets, for example 50 μm thick or of a composite material by example polymer-metal, for example aluminum.

The channel is formed for example by welding the two sheets, for example by thermal welding. The manufacturing cost is then reduced. As a variant, an assembly by gluing can be carried out. The channel thus formed is sealed. The manufacture of the channel or channels by welding allows great freedom in the shape of the channel or channels.

Preferably, the fluid circulation element comprises connectors C1, C2 at the inlet 5 and at the outlet 6 respectively, facilitating the connection of the fluid circulation element with the source of the pressurized fluid and the evacuation and facilitating the placement and removal of the circulation element in the device. These connectors C are advantageously of the quick connector type, for example they are connectors or fittings of the push-pull type, cooperating with fittings equipping the connection circuits to the source of fluid and to the means of use of the fluid. As a variant, the inlet and outlet of the pocket comprise threaded ends cooperating with threaded rings of the supply and use circuits, seals provide sealing.

The connectors can be integrated into the fluid circulation element during the manufacture of the channel by welding, the sheets being welded to the connectors, for example also made of polymer material. Thus the pocket is easily removable and replaceable.

In the present application, "a removable circulation element" means a circulation element configured to be easily removed, replaced and replaced in the heat transfer device by a person who uses the heat device, but who is not not a heat transfer device specialist implementing pressurized hydraulic circuits. The circuit to which the circulation element is connected is configured to allow this easy connection and disconnection.

A pocket comprising independent channels each provided with an input and an output does not depart from the scope of the present invention.

On the , one can see a schematic representation of an example of heat transfer device D1 according to the invention.

The device D1 comprises two heat exchange elements 8 in the form of a plate, arranged parallel to each other and delimiting a housing 10 intended to receive a pocket. Preferably, the connectors C1, C2 are arranged outside the housing to facilitate their connection.

In this example, the heat exchange elements 8 each comprise a channel 12 for the circulation of a heat transfer fluid intended to provide heat to the fluid circulating in the pocket or to extract heat from the fluid circulating in the pocket. The heat transfer fluid is, for example, water, a refrigerant preferably which does not affect the ozone layer, nor contribute to the greenhouse effect, such as R1234yf, R1234ze, or R1233zd, CO ₂ , certain hydrocarbons or a mixture of these fluids. Preferably, the channels 12 wind through the plates 8.

Plates 8 are made of a material that is a good thermal conductor, for example metal, such as steel, advantageously stainless steel, aluminum or copper.

As can be seen on the , the pocket 2 is deformed by the pressurized fluid circulating inside it, and the pocket bears against the inner face of the heat exchange plates 8. The contact between the pocket and the plates is then surface , which ensures an increased exchange surface and very good heat transfer between the fluid and the plates. The thickness of the pocket sheets is sufficiently thin to limit the heat exchange to a minimum. In addition, the diameter of the channel is small enough to allow heat exchange with all the fluid circulating in the channel.

The width L of the housing, i.e. the distance between the two inner faces of the plates, is adapted to the maximum thickness of the deformed pocket so that the channel comes into contact with the inner faces of the plates. The implementation of deformable flexible pockets makes it possible to adapt to the width of the housing and to ensure significant contact between the pocket and the heat exchange elements.

Advantageously, the outer faces of the pocket and/or the inner faces of the plates can be covered with a material improving the contact and the heat transfer between the pocket and the plates. In the case of a device intended to heat the fluid, an oil or grease type material may be used. In the case of a device intended for cooling the fluid, the liquid water depositing by condensation on the plates may be sufficient to improve the thermal contact.

The implementation of flexible pockets has the advantage of relaxing sizing constraints. Indeed, it is easy to dimension the circulation channel of the fluid to be tempered so that, in a deformed state, it comes into contact with the plates. Nevertheless, it should be noted that the deformation is such that the appearance of wrinkles which could interrupt the circulation of the fluid in the canal is avoided.

Preferably, the outer walls 9 of the device are thermally insulated to limit heat losses to the outside and optimize heat transfers between the circulation element 2 and the transfer element 8. At least one wall allows easy access to the pocket for insertion and removal.

In the example shown, a heat transfer fluid circulates in the plates. As a variant, an electric heating means or a Peltier type electric cooling means is integrated into the plates.

As a further variant, the heat transfer element(s) can combine both one or more circulation channels for a coolant and electrical heating or cooling means.

In addition, in the example shown, the heat transfer fluid circulates in the two side walls of the housing 10. Alternatively, it circulates in a single wall and the other wall is thermally insulated. As a further variant, the pocket is immersed in the heat transfer fluid; preferably the pocket is rigid as will be described below.

The operation of the heat exchange device of the will now be described. It is considered that it is desired to cool the fluid. On the , one can see a schematic representation of a heat exchange system comprising the device D1.

Bag 2 is placed in housing 10, inlet connector C1 is connected to a pressurized fluid supply S and outlet connector C2 to an outlet, for example to a valve R.

Upstream of the device D1, the fluid can be pressurized by means of a gas placed under gravity or a pushing fluid, for example tap water. Downstream, the pressure can be maintained by a pressure drop, for example by a tap R or a valve or by pouring the fluid into a pressurized receptacle.

Under the effect of the pressurized fluid circulating in the channel 4, the pocket 2 deforms in a direction normal to its surface and the walls of the circulation channel 4 come into contact with the plates 8. A cold coolant circulates in the plates 8 The heat of the fluid circulating in the channel is extracted by the coolant circulating in the plates 8. The temperature of the cold coolant is lower than the inlet temperature of the fluid circulating in the pocket. The arrows indicate the direction of circulation of the fluid.

The temperature of the fluid between the channel inlet and the channel outlet is then lowered.

The operation of the device for heating a fluid is similar to the operation described above but a coolant, at a temperature higher than the temperature to which it is desired to heat the fluid, circulates in the plates.

For example, in an application for cooling beer contained in a first cask, the inlet connector is connected to the first cask, the cask being connected to a source of CO ₂ under pressure. The beer circulates in the ladle and comes out cooled at the tap. The bag can be connected to a second keg when the first keg is empty.

At the end of the period of use, the ladle is purged and is disconnected from the drum and from the tap, it is removed from the housing 10 and is discarded or sent to a recycling circuit, possibly for a refilling. It is replaced by a new pocket. The maintenance of the beer dispensing system is then significantly simplified. Indeed, the low cost of the bag combined with its ease of installation make it possible to change it with sufficient frequency to ensure the sanitary quality for food fluids or to maintain satisfactory exchange conditions for a fluid making deposits. . The invention makes it possible to maintain adequate sanitary conditions in the exchanger by changing the pocket.

As an example, using a pocket of a rectangular shape with a size of 21 cm × 29.4 cm in which a channel of a few millimeters in diameter and a length of about 10 m in length, it is possible to lower with a heat carrier at 0°C and 2°C, the temperature of a fluid of the water type from 25°C to a temperature of the order of 2°C to 4°C in about twenty seconds for a flow rate of 0.02 kg /s and in about ten seconds for a flow rate of 0.05 kg/s.

The performance of the pockets according to their external dimensions will be presented.

Consider a bag made of polymer material whose walls have a thickness of 20 μm, and comprising a channel whose substantially rectangular section has a length between 2 mm and 4 mm and a width between 6 mm and 12 mm and having a length between the two ends 5 and 6 between 4 m and 9 m.

For a beer flow rate of 0.05 kg/s, maximum pressure drops at 700 mbar, the bag has an external format of the order of 2.2 times a standard A4 format, the A4 format being a rectangle of 21 cm × 29.7cm.

For a nominal value beer flow of 0.025 kg/s and for a maximum pressure drop of 700 mbar, a pocket format of the order of 1.3 times the A4 format is sufficient.

In the case of a rigid steel ladle, considering a channel section with a length between 3 mm and 4 mm and a width between 11 mm and 12 mm and a length between the two ends 5 and 6 between 5 m to 6 m, we obtain for a lower pressure drop, a pocket of dimensions of the order of A4 or even lower.

By way of comparison, the pockets according to the invention make it possible to obtain substantially the same performance as a tube of circular section with a diameter of between 4 mm and 12 mm and a length of between 6 m and 15 m immersed in a bath of water and 20% glycol.

The conditions are:
- Lowering the temperature of the beer from 25°C to 4°C,
-Beer pressure 1 bar,
-Cooling fluid temperature between 0°C and 2°C,
- Coolant flow rate between 0.5 kg/S and 2 kg/s,
-Diameter of the heat transfer fluid channel between 10 mm and 15 mm,
-Distance between two tube passes of the order of the half-diameter of the tube.

On the , the device D2 comprises three heat exchange elements 8 and two fluid circulation elements 2, each fluid circulation element 2 being disposed between two heat exchange elements 8. A heat exchange element 8 participates to the delimitation of the two housings 10. The two circulation elements 2 are connected in parallel to the power source and to the use, which makes it possible to increase the flow rate of fluid whose temperature is modified. It will be understood that more than two circulation elements each received in a housing can be implemented. As a variant, the pockets are each connected at the outlet to a separate drain, for example to two taps.

As a variant, the two fluid circulation elements are connected in series, which makes it possible either to vary the temperature of the fluid more significantly, or to increase the flow rate of tempered fluid.

On the , one can see another example of heat exchange device D3 according to the invention allowing a heat exchange between two pockets.

The device comprises a heat exchange element 14 made of a material that is good, or even very good, thermal conductor, and two fluid circulation elements 2, 2' on either side of the thermal conductor element 14. Each circulation element fluid 2, 2' is connected to a source of fluid at different temperatures and to a different outlet. Thus, during the circulation of the two fluids in the heat exchange elements, they exchange heat through the heat exchange element. The fluids circulating in the two fluid circulation elements 2 and 2' can be identical or different.

Preferably, the heat exchange element is a metal, for example copper, aluminum or stainless steel. For such materials, the thickness of the heat exchange element can be between 2 mm and 5 mm.

Preferably, the device comprises two housings 16 separated by the heat exchange element. The width of the housings is dimensioned to receive the two pockets 2, 2' and so that once deformed by the pressurized fluids they are in intimate contact with the heat exchange element 14. Thus the heat transfer is optimized . Preferably, the outer walls 18 of the device are thermally insulated to limit heat loss to the outside and optimize heat transfer between the two circulation elements. The width of the housings 16 is chosen to ensure significant contact of the pockets against the heat exchange element 14.

The device according to may comprise more than one heat exchange element 14 and more than two fluid circulation elements. For example, the device comprises two heat exchange elements 14 and three fluid circulation elements. For example, the fluids circulating in the pockets 2 located at the ends are the same or are different, and the fluid circulating in the central pocket 2′ is at a different temperature, the latter is then heated or cooled by heat exchange with the other two fluids through the heat exchange elements 14.

It will be understood that the vertical orientation in FIGS. 2 to 5 is not imperative and that the pockets and the heat exchange and coolant circulation elements can have any orientation, for example a horizontal orientation.

Pockets of different dimensions can be implemented.

In another exemplary embodiment, the removable fluid circulation element is a rigid element, i.e. which deforms little or not at all under the effect of the pressure circulating therein.

For example, the fluid circulation element is made from two steel sheets, advantageously stainless steel, stamped and brazed to each other and delimiting the circulation channel between them, the ends of the channel comprise quick connectors, similar to pocket 2, which allow quick connection and disconnection of the circulation element with the fluid supply circuit. For example, stainless steel sheets have a thickness of 200 μm.

In this example, the distance between the heat exchange elements is chosen so as to allow the circulation element to be placed between the two heat exchange elements in contact with them.

The circulation element is removed from the heat exchange device and can be more easily cleaned outside the device, before being replaced. It can be envisaged to mount a clean circulation element while the circulation element is being cleaned, which makes it possible to reduce the time of non-use of the device.

The invention applies to the heating or cooling of liquid foodstuffs for catering or in a domestic setting.

The invention is particularly interesting for production lines in the food industry or food or other crafts which require maintenance of the heat exchangers for sanitary maintenance, due to deposit or change of fluid.

In particular, the invention can be used for collective catering where large quantities of fluid must be brought to temperature for consumption, possibly in an unscheduled manner. In this case, the invention makes it possible to condition various fluids in a versatile way without prior heating or cooling time.

The invention can be applied to other food or non-food fluids, for example it can be used to apply heat treatment to fluids with a view to subsequent use. For example, it can be envisaged to heat fluids containing biological cells or chemicals reacting under the effect of heat. The variation in fluidity of the liquids after transformation and their compatibility with the bag material will be taken into account.

The invention makes it possible to dispense with the exchanger cleaning operations which are long, may require chemicals of the acid or base type which may be polluting and expensive. These operations also require control which is avoided thanks to the invention.

Claims (17)

Heat exchange device for modifying the temperature of at least a first fluid, comprising at least one heat transfer element (8, 14) and at least one circulation element (2) of a first fluid configured to be in contact with the heat transfer element (8, 14), the circulation element of a first fluid comprising a circulation channel (4) of the first fluid between an inlet (5) and an outlet (6), of which at least one wall is intended to be in contact with the heat transfer element, in which said circulation element (2) is removably mounted and in which the inlet (5) of the channel comprises a first connector configured to connecting the circulation element to a first circuit connected to a source of first fluid and the outlet of the channel comprising a second connector configured to connect the circulation element of a first fluid to a second circuit connected to means of use of the first fluid, so that the elem ent circulation of a first fluid is removable. Heat exchange device according to claim 1, in which the circulation element (2) for a first fluid is made of a flexible material defining a circulation channel (4) for the first fluid between an inlet (5) and a outlet (6), said first fluid circulation element (2) being configured to deform when the first fluid under pressure circulates in the circulation channel (4) and to come into contact with the at least one heat transfer element (8, 14), so that the first fluid exchanges heat with the heat transfer element (8, 14) through the flexible material. Heat exchange device according to Claim 2, in which the circulation element (2) of the first fluid comprises two superposed sheets, each of the sheets being made of polymer, of metal or of a composite polymer and metal material and in which the circulation channel (4) is formed by welds between the two sheets. A heat exchange device according to claim 3, wherein the polymer is polyethylene and the metal is aluminum. Heat exchange device according to one of Claims 1 to 4, in which the heat transfer element (8) comprises at least one channel (12) for the circulation of a coolant. Heat exchange device according to one of Claims 1 to 5, in which the heat transfer element (8) comprises electrical heating means. Heat exchange device according to one of Claims 1 to 6, comprising at least two heat transfer elements (8) delimiting between them a housing (10) configured to receive the circulation element (2) of a first fluid. Heat exchange device according to Claim 7 in combination with Claim 2, in which the spacing between the two heat transfer elements (8) is such that the circulation element (2) of a first fluid in its deformed state is in contact with the two heat transfer elements (8). Heat exchange device according to Claim 7 or 8, comprising several circulation elements (2) of a first fluid configured to be supplied in parallel or in series and several housings (10), each receiving a circulation element (2) of a first fluid. Heat exchange device according to one of Claims 1 to 6, comprising at least one circulation element (2') for a second fluid arranged on the opposite side of the heat transfer element (14) with respect to the circulation element (2) of a first fluid so that there is a heat transfer between the first fluid and the second fluid. Heat exchange device according to Claim 10, in which the circulation element (2') for a second fluid is made of a flexible material defining a circulation channel for the second fluid between an inlet and an outlet, said circulation (2') of the second fluid being configured to deform when the second fluid under pressure circulates in the circulation channel. Heat exchange device according to one of Claims 1 to 11, comprising thermally insulating outer walls (9, 18). System for modifying the temperature of at least a first fluid comprising, at least one transfer device according to claim 7, 8 or 9, a source of first fluid under pressure (S) at a first temperature connected to the inlet of a circulation element for a first fluid, a source of coolant connected to a heat transfer element, and means for using (R) the first fluid at a second temperature different from the first temperature. System according to the preceding claim forming an on-demand beer dispensing system, the first fluid being beer. System for modifying the temperature of at least a first fluid comprising, at least one transfer device according to claim 10 or 11, comprising a source of a first fluid under pressure connected to the circulation element of a first fluid and a source in a second fluid under pressure connected to the circulation element in a second fluid Method of using a system according to claim 13 or 14 comprising:
- the placement of a circulation element (2) of a first fluid between two heat transfer elements (8),
- the connection of the circulation element (2) of a first fluid to the supply source (S) of a first pressurized fluid and to the means of use (R) of the fluid at the second temperature,
- the sampling of the first fluid at the second temperature after circulation of the first fluid in the circulation element of a first fluid,
- the disconnection of the circulation element (2) of a first fluid and the withdrawal thereof,
-the connection of a circulation element (2) of a first new fluid to the supply source (S) of a first fluid and to the means of use (R) of the first fluid. Method of using a system according to claim 15 comprising:
- the positioning of a circulation element (2) for a first fluid and of a circulation element (2') for a second fluid on either side of the heat transfer element ( 14),
-the connection of the circulation element (2) of a first fluid to the supply source of a first pressurized fluid and to the means for using the fluid at the second temperature, and the connection of the circulation (2') of a second fluid to the source of supply of a second pressurized fluid and to the means of second use,
- the sampling of the first fluid at the second temperature after circulation of the first fluid in the circulation element (2) of a first fluid,
- the disconnection of the circulation element (2) of a first fluid and/or of the circulation element (2') of a second fluid and withdrawal of one or the other or both,
-the connection of a circulation element (2) of a first new fluid to the supply source of a first fluid and to the means for using the first fluid, and/or the connection of a circulation element ( 2′) of a second new fluid to the supply source of a second fluid and to the means for using the second fluid.