DEVICE FOR THERMODYNAMICAL HEATING OF A LIQUID CONTAINER AND CORRESPONDING INSTALLATION METHOD

Description

FIELD OF INVENTION

[0001] The present invention relates generally to thermodynamic heating devices for liquid tanks, such as thermodynamic water heaters. EARLIER ART

[0002] Thermodynamic heating devices are known for heating a tank filled with liquid, such as water. Documents CN210128509 U and CN106940087 A describe such thermodynamic heating devices.

[0003] These units include a heat pump system containing a refrigerant. Around the tank is a part of the refrigeration circuit, called the condenser, which heats the liquid inside the tank. The refrigerant condenses in the circuit around the tank to heat the liquid through heat transfer. Thermal paste may be applied between the condenser and the tank to optimize heat exchange.

[0004] It is known, in particular from patent FR3077622, ​​for the creation of a thermodynamic water heater condenser formed by a tube placed by manual or semi-automatic spiral winding around the tank as illustrated in the Figure 1 .

[0005] Thus, in the example illustrated in the Figure 1 , the thermodynamic water heater 1' comprises a tank 2 and a condenser 3' which includes a tube wound in spirals around the peripheral wall 20 of the tank 2.

[0006] The spiral winding operation of the condenser tube around the tank takes several minutes and cannot be completed within the typical cycle time of a water heater production line, which is approximately 30 to 45 seconds. Therefore, the spiral winding operation is performed outside the production line flow, requiring the maintenance of spare parts and a complex production organization.

[0007] In addition, there are other types of condensers in the form of belts, such as belts with micro-channels or so-called "roll bond" belts (English terms literally translating to winding bond).

[0008] However, for microchannel belts, extruded aluminum tubes are welded to vertical manifolds. Welded assembly of the tubes to the manifolds increases the risk of refrigerant leakage. Furthermore, the welding process requires specialized furnaces and manual tube placement on the manifold, reducing the repeatability of the manufacturing process. Finally, the volume of the manifolds increases the amount of refrigerant used, without the refrigerant in the manifold contributing to the heat exchange between the tank and the condenser.

[0009] As for roll-bond belts, these belts are manufactured using a cold welding process involving the rolling of two metal sheets, which are then pressurized to form the circuit. These roll-bond belts are difficult to manufacture because the material used may not withstand the forming pressure, and it is challenging to design a circuit sufficiently resistant to operating pressure. Furthermore, this type of belt requires good cylindricity and a smooth surface finish on the tank, which is difficult to achieve, to ensure proper contact and heat exchange between the belt and the tank. The rigidity of the panel formed by the metal sheets makes it difficult to apply around the tank, thus creating a risk of condenser damage and performance loss.

[0010] The present invention aims to propose a new thermodynamic heating device and a corresponding condenser installation method that allows at least partially to overcome all or part of the problems described above. SUMMARY OF THE INVENTION

[0011] For this purpose, the invention relates to a thermodynamic heating device according to claim 1.

[0012] This condenser design, formed from an extruded tube bent to create a shape when applied to the tank, allows for easy and rapid application of the condenser around the tank, similar to a belt, thanks to the tube's winding elements which have internal bends opposite to the connecting bends between the winding elements. This extruded tube's shape—which, in its flat configuration, resembles a coil—allows the coil to be automatically applied to the tank's peripheral wall and pressed against the tank as it rotates once, thus encircling the tank with the coil.This operation of placing the condenser on the tank can be carried out on a production line of the device, that is to say within the cycle time of the production line, preferably less than 45 seconds, without having to temporarily store the tank off the production line to carry out the application of the condenser on the tank.

[0013] The serpentine shape - considered flat before application around the tank - formed by the succession of the tube winding elements, allows this flat serpentine shape of the condenser to be brought laterally onto the tank to encircle it, which allows the application of the condenser onto the tank in a simple operation of applying it to the tank and fixing or tightening the two ends of the band around the tank towards each other.

[0014] The fact that a first portion of the tube of each winding element extends around a part of the circumference of the tank, around the longitudinal axis of the tank (and similarly for the second portion) followed by an internal U-shaped return, and that this internal U-shaped return of each winding element extends in a plane orthogonal to the plane in which the first or second portion of the tube extends, makes it possible to obtain a configuration of the capacitor thanks to which the heat exchanges between the capacitor and the tank are improved in a simple way.

[0015] In particular, such a condenser configuration allows the refrigerant to travel around the upper part of the tank over a long winding distance before reaching the lower part of the tank, which allows for the generation of water stratification, so that hot water is in the upper part where the water is drawn, while the (cold) water inlet is at the bottom in a water heater.

[0016] The heating appliance, such as a thermodynamic water heater, may also include one or more of the following characteristics taken in any technically permissible combination.

[0017] Preferably the condenser tube through which the refrigerant is intended to circulate is made of a single piece without joining several sections of tube.

[0018] According to one embodiment of the invention, the winding elements and the U-shaped connecting returns are formed by a single tube without joints, such as welds, which is shaped to obtain, when flat, a coil which, when applied against the tank, forms the winding elements and the connecting returns between the winding elements.

[0019] According to one embodiment of the invention, the inlet is formed by a portion of straight tube which extends parallel to the longitudinal axis of the tank, and which is extended by the first winding element.

[0020] According to one embodiment of the invention, the outlet is formed by another straight portion of the tube which extends parallel to the longitudinal axis, being further away from the longitudinal axis than the inlet.

[0021] According to one embodiment of the invention, the extruded tube is made of aluminum or copper.

[0022] According to one embodiment of the invention, the tube has a circular or D-shaped cross-section.

[0023] The internal U-shaped return of each winding element extends in a plane orthogonal to the plane in which the first or second portion of the tube extends.

[0024] According to one embodiment of the invention, the winding elements and the connecting returns form, in a flat configuration, a coil, called the main coil, which, in the applied state against the peripheral wall of the tank, forms a belt whose end is formed by the connecting returns located on the same first side of the coil, and whose opposite end is formed by the returns located on the same second side of the coil, opposite to the first side.

[0025] According to one embodiment of the invention, the bent extruded tube of the condenser also includes an additional coil, the straight parts of which are, in the flat configuration of the tube, orthogonal to the straight parts of the main coil, the additional coil being disposed between the outlet and the main coil, and being applicable to the under wall of the tank considered in the vertical position in the tank's operating configuration.

[0026] According to one embodiment of the invention, the thermodynamic heating device includes a holding system configured to keep said portions of the tube winding elements separated so as to maintain the shape of the belt.

[0027] According to one embodiment of the invention, the thermodynamic heating device includes clamping means to bring the ends of the belt formed by the bent extruded tube together, to tighten the belt against the tank.

[0028] According to one embodiment of the invention, the clamping means are fixed to the holding system.

[0029] According to one embodiment of the invention, the clamping means comprise hooks and springs.

[0030] According to one embodiment of the invention, each of the first and second portions of each winding element extends along an arc of a circle around the longitudinal axis of the tank. Preferably, the diameter of each of said arcs of a circle is greater than the radius of curvature of the U-shaped return. Advantageously, each of the first and second portions of each winding element is longer than the length of the U-shaped return that connects them.

[0031] According to one embodiment of the invention, each of the first and second portions of at least a part of the, preferably of each, winding elements extends around the longitudinal axis over an arc of a circle of more than 180°, preferably over an arc of a circle of more than 270°, advantageously over 330°.

[0032] According to one embodiment of the invention, at least one part, preferably each of the first and second portions, is of a length greater than the U-shaped return that connects them.

[0033] According to one embodiment of the invention, the length of each of the first and second portions of each winding element is greater than the cumulative length of the U-shaped returns of the winding elements.

[0034] According to one embodiment of the invention, each of the first and second portions of each winding element develop in a plane transverse to the longitudinal axis of the tank.

[0035] According to one embodiment of the invention, the first and second portions of each winding element extend in planes parallel to each other.

[0036] According to one embodiment of the invention, the first and second portions of each winding element extend in planes parallel to the planes in which the first and second portions of each other winding element extend.

[0037] According to one embodiment of the invention, the tank comprises a water inlet at the bottom and a water intake zone at the top. The winding element closest to the refrigerant inlet, relative to the other winding elements, is located at the top of the tank (that is, on the side of the water intake zone). The refrigerant thus flows through the winding elements from top to bottom, first heating the top of the tank. The physical hot water outlet of the tank (corresponding to a connection point between the tank and a domestic hot water circuit) can be located at the same point as the water intake zone at the top of the tank or positioned at the bottom of the tank and connected by a pipe to the water intake zone at the top of the tank.

[0038] Advantageously, the winding element closest to the refrigerant outlet is located in the lower part of the tank (in other words, on the cold water inlet side).

[0039] The distance between the refrigerant inlet and a winding element, as well as the distance between a winding element and the refrigerant outlet, is understood to be the distance that the refrigerant must travel between said winding element and said refrigerant inlet or outlet.

[0040] The invention also relates to a method for automatically placing a bent extruded condenser tube onto a tank of a thermodynamic heating device, the method being in accordance with claim 14.

[0041] The process makes it possible to obtain a thermodynamic heating device as proposed above.

[0042] According to one embodiment, the coil has portions of different cross-sections, said portions of the coil being obtained for example by joining together several portions of tube of different cross-sections or by deforming portions of the coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Other features and advantages of the invention will become apparent from the following description, which is purely illustrative and not limiting and should be read in conjunction with the accompanying drawings, on which: [ Fig. 1 ] there Figure 1 is an illustration of a thermodynamic heating apparatus comprising a tank and a condenser which includes a tube wound in spirals around the tank according to a known example of the prior art; [ Fig. 2 ] there Figure 2is an illustration of a condenser according to an embodiment of the invention made from an extruded tube bent into a serpentine shape to form a belt around a tank of a thermodynamic heating device according to an embodiment of the invention; [ Fig. 3 ] there Figure 3 is an illustration of clamping elements that can be used to maintain tension on the end portions of the belt formed by the condenser tube in order to press said belt against the tank of a thermodynamic heating device according to an embodiment of the invention, the condenser being, for example, that of the Figure 2 or of the Figure 4 ; Fig. 4 ] there Figure 4is an illustration of a condenser tube for a thermodynamic heating device according to an embodiment of the invention, in the flat state of the tube, the tube being shaped to present at least one part in the form of a coil when flat, before application of the flat form of the condenser onto the tank of the thermodynamic heating device and rotation of the tank to encircle the tank with said tube, the lower part of the coil being intended to be pressed against an elliptical lower part of said tank. DETAILED DESCRIPTION

[0044] The invention is described in more detail below with reference to the accompanying drawings, in which embodiments of the invention are shown. In the drawings, the size and relative sizes of the elements may be exaggerated for clarity. Similar numbers refer to similar elements in all drawings. However, the invention can be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. The scope of the invention is defined by the claims.

[0045] A reference throughout the specification to "an embodiment" means that a particular feature, structure, or characteristic described in relation to an embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrase "in an embodiment" in various places throughout the specification does not necessarily refer to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments within the scope of the invention as defined by the claims.

[0046] As schematically represented on the Figure 1, a tank 2 of a thermodynamic heating device contains liquid, for example water, which is intended to be heated by a refrigeration circuit of a heat pump (HP) system of the device which will be described later.

[0047] For example, the device is a water heater. Although the following description refers to a water heater, it should be noted that it applies to any type of thermodynamic heating device that includes a liquid tank.

[0048] Tank 2, filled with water, extends along a longitudinal dimension which, here, is taken along the vertical axis since the tank is positioned vertically. However, the following description also applies to a tank positioned horizontally (horizontal longitudinal dimension) or inclined.

[0049] Typically, in tank 2, heated water is drawn from one end or uppermost point of the tank, while unheated water is introduced from the opposite end or lowermost point. The various connections for water injection and withdrawal are not shown for clarity. The tank has a wall 20, which is generally cylindrical and closed at its two opposite ends by two caps or ends, and is roughly elliptical.

[0050] As illustrated in the Figure 1 The tank 2 has a peripheral wall 20 extending around a longitudinal axis A2. The tank 2 also has a bottom wall 22 forming the base of the tank and extending the peripheral wall 20 to the lower part of the tank. The tank also has a top wall 21 forming the top of the tank and extending the peripheral wall to the upper part of the tank.

[0051] The water heater also includes a heat pump system 6 which comprises a refrigeration circuit, part of which is applied to the tank 2 and which contains a refrigerant, for example, R134a. The part of the refrigeration circuit that is applied around the tank forms the condenser of the circuit.

[0052] It should be noted that, as detailed below, the condenser 3 according to the invention, examples of which are illustrated in Figures 2 And 4 , differs from the condenser 3' of the Figure 1 known from the state of the art due to the fact that, in the Figure 1 , the condenser 3' is formed by a spiral winding around the tank, whereas in the invention and as illustrated for example in the Figure 2 and to the Figure 4 , condenser 3 presents - in a flat configuration and as visible at the Figure 4- a serpentine shape 38, which is applied laterally against the tank 2 in the manner of a belt, as illustrated in the Figure 2 .

[0053] The condenser 3 includes an extruded tube which forms a refrigerant circulation circuit which includes an inlet 301 and an outlet 399. The tube is for example made of aluminum or copper.

[0054] Applying the condenser 3 according to the invention to the tank 2 requires only a single rotation of the tank around its axis A2 to laterally attach the serpentine shape (shown below) in which a portion of the tube is formed, and thus encircle the tank, whereas the spiral winding of the condenser 3' of the Figure 1 around the tank requires as many rotations of the tank as there are turns.

[0055] A simple and reliable thermodynamic water heater 1 is thus proposed, in which the condenser 3 comprises an extruded refrigerant circulation tube that is bent so that at least a portion of the tube is formed into a coil 38. This coil is flat before application to the tank, allowing the flat shape of the condenser coil 38 to be easily applied to the peripheral wall of the water heater tank 2, particularly on a water heater production line. The condenser tube containing the refrigerant is in thermal contact with the external face of the tank wall. Condenser

[0056] In a flat configuration and as illustrated in the Figure 4The condenser tube 3 comprises straight sections 310, 312, 320, 322, 330, 332 connected by bends 311, 321, 331, 313, 323, 333 (U-shaped return) with alternating directions of concavity from one bend to the next. In other words, a given bend is obtained by curving the tube in one direction, and the next bend is obtained by curving the tube in the opposite direction. The condenser tube, thus bent, forms the coil 38, called the main coil, which comprises parallel straight sections and bends between these straight sections. The condenser inlet communicates with one end of the coil, and the condenser outlet communicates with the other end of the coil.

[0057] Each set of two straight parts 310, 312; 320, 322; 330, 332 connected together by an elbow or return, called internal elbow or return 311, 321, 331, forms a winding element 31, 32, 33. The winding elements 31, 32, 33 are connected together by elbows or returns 313, 323, 333, called connecting elbows or returns bent in the opposite direction to the internal elbows or returns of the winding elements.

[0058] According to a particular embodiment of the invention, the coil 38 may have portions of different cross-sections. These portions of the coil 38 may be obtained by joining several tube portions of different cross-sections end to end or by deforming portions of the coil.

[0059] It can be anticipated that the condenser tube 3 also includes an additional coil 39, the straight sections of which, in the flat configuration, are orthogonal to the straight sections of the main coil 38. The additional coil 39 is located between the outlet 399 and the main coil 38, and can be applied to the underside wall 22 of the tank 2, considered in the vertical position in the water heater's operating configuration. In the example of the Figure 4 , the additional coil 39 is connected by a part 340, 333 of the tube to the main coil 38 formed by the winding elements 31, 32, 33. Winding elements

[0060] As illustrated in the Figure 2, in the applied state of the condenser 3 around the tank 2, the tube of the condenser 3 includes a first winding element 31 which includes a first portion 310 extending around at least a part of the circumference of the tank (around the longitudinal axis A2 of the tank 2), followed by a U-shaped return 311 (elbow).

[0061] In the applied state of the condenser 3 on the tank 2, the U-shaped return 311 is such that the bending axis A311 around which the tube is bent to obtain the U-shaped return (i.e. the axis of the through opening defined by the bend - U-shaped return) is transverse, preferably orthogonal, to the longitudinal axis A2 of the tank 2. In other words, the U-shaped return 311 extends in a plane orthogonal to the plane in which the first portion 310 extends around the tank.

[0062] In the flat configuration of the tube in a plane, i.e. before application on the tank, the bending axis of the U-shaped return, i.e. the axis of the through opening defined between the two branches of the U, is orthogonal to said plane in which the tube extends before application on the tank.

[0063] The U-shaped return 311 is extended by a second portion 312 which develops parallel to the first portion 311, around at least part of the circumference of the tank 2, in the opposite direction to the first portion 310 (by reference to a direction of travel of the tube from the inlet towards the outlet of the tube).

[0064] The condenser 3 comprises several winding elements 32, 33 made like the winding part 31, and which are connected to each other by U-shaped returns. In particular, the second portion 312 of a first winding element 31, located (in the water heater operating configuration) above a second winding element 32, is connected to the first portion 321 of a second winding element 32 by a U-shaped return 313.

[0065] Each U-shaped return 313, 323 called a link return, which connects two winding elements 31, 32, 33, has a concavity opposite to the internal U-shaped returns 311, 321, 331 of the winding elements.

[0066] Similar to the internal U-shaped return of a winding element, each connecting return 313 between two winding elements 31, 32 is such that the bending axis A313 around which the tube is bent to obtain the U-shaped return (i.e., the axis of the through opening defined by the bend – U-shaped return) is transverse, preferably orthogonal, to the longitudinal axis A2 of the tank. In other words, each U-shaped connecting return extends in a plane orthogonal to the plane in which each of the portions 312, 320 of winding elements 31, 32 connected by said connecting return 313 is developed.

[0067] In other words, and similarly to the U-shaped return of a winding element, in the flat configuration of the bent tube, i.e. before application to the tank, the bending axis A313 of a U-shaped connection return 313, i.e. the axis of the through opening defined between the two branches of the U, is orthogonal to the said plane in which the tube extends before application to the tank.

[0068] According to a preferred embodiment of the invention, the winding elements and the U-shaped connecting returns are formed from a single extruded tube. In other words, the condenser tube, which extends around the tank and through which a refrigerant is intended to circulate, is a single tube without any joints such as welds. This tube is shaped to obtain at least the coil that forms the winding elements and the connecting returns between the winding elements. The U-shaped connections can vary from one another, for example, to generate a variable spacing. Entrance and exit

[0069] The inlet 301 can be formed by a straight section of tube extended by the first winding element. The first winding element 310, which extends the inlet 301, is located at the top of the tank. The tank has a water intake zone, also located at the top, while the cold water inlet is located at the bottom. The water drawn can exit through a water outlet, which can be located at the top of the tank, like the intake zone, or at the bottom, connected to the intake zone by a tube. The tank is thus configured so that hot water is drawn from the top, while cold water enters at the bottom.The refrigerant can thus circulate in the condenser tube from the first winding element 310 located in the upper part of the tank, going down towards the lower part of the tank through the other winding elements 312, 320, 322, located below each other.

[0070] This design allows for efficient heat exchange between the condenser fluid, which first passes through the coils located at the top of the tank, and the upper part of the tank where the water to be heated is located. This water is then drawn from the top of the tank during use. This condenser arrangement creates and maintains water stratification within the tank, with warmer water at the top than at the bottom. This ensures a reliable and efficient supply of hot water, as the water used is drawn from the top of the tank. The tank outlet is designed to be connected to a domestic hot water (DHW) system.

[0071] The outlet 399 can be formed by a straight tube portion extending from the last winding element or the remaining part 39 of the tube extending between the last winding element and the outlet 399. The outlet 399 extends upwards, (considering the direction of fluid flow in the water heater's operating configuration).

[0072] The remaining portion 39 of the tube may include part of an additional winding element, which has only a first winding portion as in the example of the Figure 2 , and / or a section of corrugated or serpentine shaped tubing intended to come around and / or against the external face of the bottom of the tank (i.e. the bottom wall of the tank).

[0073] Preferably, output 399 extends substantially parallel to input 301.

[0074] The outlet 399 which rises from the last winding element, or the remaining part of the tube which extends between the last winding element and the outlet 399, preferably extends at the spacing of the winding elements of the tube to avoid heat exchange between the winding elements and said outlet. Tube

[0075] According to a preferred embodiment of the invention, as described above, the winding elements and connecting returns are formed from a single piece of one another. In other words, the winding elements are seamless, without any welds or joints between them. The winding elements are formed from an extruded tube that is shaped, preferably by bending: to form the U-shaped returns that connect the winding elements together, and to form, for each winding element, the U-shaped returns that connect the first and second portions of a winding element together.

[0076] The extruded tube is also shaped to form the inlet and outlet, which preferably take the form of straight portions, and to form the possible remaining part 39 between the outlet and the winding elements.

[0077] According to a less advantageous alternative embodiment, the tube from which the condenser is formed can be made by joining, for example, welding several sections together. It can thus be provided that different sections of the condenser tube are formed separately and then joined together, while having a section which, when flat, forms a coil and is deformable to be applied around the peripheral wall of the tank like a belt and possibly over the lower part of the tank.

[0078] The condenser tube may have a circular or elongated cross-section with a flat part, for example in a D shape. The cross-section may vary along the tube. Belt

[0079] The tube formed so that the winding elements 31, 32, 33 form - in flat configuration - a coil 38 can be used as a belt one end of which is formed by the returns 311, 321, 331 (or elbows) located on the same first side of the coil, and the opposite end of which is formed by the returns 313, 323, 333 (or elbows) located on the same second side of the coil, opposite to the first side.

[0080] The initially flat belt formed by the bent extruded tube can then be applied and deformed (curved) against the tank to fit against and around its peripheral wall, thus encircling it. Optionally, an additional section of the condenser, extending from the main coil and forming a supplementary coil, can be placed against the lower part of the tank. Attachment system

[0081] Preferably, a fastening system 4 is provided to allow the ends of the belt to be brought together or interlocked, which are formed, on the one hand, by the connecting elbows 313, 323 which link the winding elements 31, 32, 33 together and, on the other hand, by the internal elbows 311, 321, 331 of each winding element 31, 32, 33.

[0082] The fastening system 4 allows the belt formed by the condenser tube 3 to be tightened against the tank 2. In other words, the fastening system 4 acts on the condenser tube 3 in the direction of reducing the diameter of the winding elements around the tank to allow them to come as close as possible to the peripheral wall of the tank, preferably to press them against the tank.

[0083] The fastening system 4 includes, for example, attachment devices, each comprising two hooks connected by a spring. One hook is attached to one end of the belt and the other to the other end of the belt.

[0084] Alternatively, the belt formed by the main coil 38 of the tank can be mechanically tensioned around the tank using other clamping elements, such as hose clamps. Alternatively, or in combination with other methods, the belt can be secured around the tank by welding, or by screwing if necessary. Spacing retention device

[0085] According to one embodiment of the invention, the condenser tube 3 is provided with a spacing retaining device 5 which is fixed to the condenser tube 3 and which is configured to keep apart from each other the portions 310, 312, 320, 322, 330 of the winding elements 31, 32, 33, which are straight in the flat state of the bent tube, and which extend parallel to each other.

[0086] The spacing support device 5 may include bars that form uprights extending orthogonally to the straight portions of the condenser winding elements. These uprights of the spacing support device 5 may be hollow but are not traversed by a refrigerant fluid.

[0087] The spacing retention device 5 may include fixing elements assembled to the condenser tube by clipping, welding, friction etc... The retention system may also include an adhesive film, an aluminum sheet or a net).

[0088] As illustrated in the Figure 3 , the fastening system 4 can be attached to the spacing retaining device 5. Example of a condenser design

[0089] According to one embodiment of the invention and as illustrated in the Figure 4 In a flat view, the condenser tube can be formed to present, from the inlet to the outlet: a straight portion forming the inlet 301; several winding elements 31, 32, 33 extending from one another to form a main coil. The straight portion of the inlet extending perpendicularly to the straight portions of the winding elements 31, 32, 33; a lower portion 39 in the form of an additional coil whose straight portions are perpendicular to the straight portions of the winding elements 31, 32, 33; a straight portion forming the outlet 399 which extends parallel to the inlet 301 and rises from the lower portion 39 to the level of the inlet 301 (above the first winding element 31 of the coil).

[0090] Of course, other forms are possible.

[0091] The invention thus makes it possible to obtain a condenser by deformation (bending) of an extruded tube to obtain at least one part which has a flat serpentine shape in order to put the condenser around the tank by bringing the condenser coil laterally and pressing it against the peripheral wall of the tank so that, with a single rotation of the tank, the tank is encircled with the condenser (as opposed to the solution of the technique where a spiral winding of a tube around the tank would require as many rotations of the tank as there are turns to be made).

[0092] Indeed, the condenser tube can be pre-formed as explained above to present—in a flat configuration—a main serpentine section. This allows one face of the serpentine to be placed against the peripheral wall of the tank, and the opposite lateral sections of this serpentine, defined by sets of bends curved in opposite directions, to be joined or brought together by applying the condenser against the tank, thus encircling the tank with the condenser. Such an operation of applying the pre-formed condenser tube can be carried out in the production flow, at the rate of the water heater production line.

[0093] The invention thus makes it possible to: to achieve a reduced cycle time, and thus a gain in productivity and production capacity; to carry out the production of the belts at the edge of the line in order to simplify and minimize the number of belt references; a possible automation of the placement of the belt on the tank, with a robot which holds and applies the belt against the tank while it rotates on itself, which brings a saving in direct labor cost; an application of the belt on the tank in the production flow of the tank, which makes it possible to do without an intermediate storage area for the tanks.

[0094] Furthermore, the absence or reduced number of welds required to produce the condenser formed by bending allows for a decrease in the risk of refrigerant leakage from the condenser.

[0095] The same tube reference can be used to pre-form different sizes of condenser coils depending on the size or shape of the tanks to be fitted with the condenser.

[0096] The invention is not limited to the embodiments illustrated in the drawings. The scope of the invention is defined by the accompanying claims.

[0097] Furthermore, the term "including" does not exclude other elements or steps. In addition, features or steps described with reference to one of the embodiments set out above may also be used in combination with other features or steps from other embodiments set out above.

Claims

1. Thermodynamic heating apparatus (1) comprising: - a tank (2) having a longitudinal axis (A2), the tank being intended to be filled with liquid, for example water; - a heat pump system comprising a condenser (3) having an inlet (301) for refrigerant fluid and an outlet (399) for said fluid, characterized in that the condenser comprises an extruded tube through which the refrigerant fluid is intended to circulate and which forms a belt around the tank (2), in order to heat the liquid in the tank, the tube comprising a plurality of winding elements (31, 32, 33), each winding element (31, 32, 33) comprising a first tube portion (310, 320, 330), a second tube portion (312, 322, 332) and a U-shaped return (311, 321, 331), said first tube portion (310, 320, 330) extending around part of the circumference of the tank, about the longitudinal axis (A2) of the tank (2), followed by said U-shaped return (311, 321, 331), called internal return, formed by bending the tube; the internal U-shaped return (311, 321, 331) being extended by said second tube portion (312, 322, 332) which develops, around part of the circumference of the tank (2), about the longitudinal axis (A2) of the tank (2), in the opposite direction to the first tube portion (310, 320, 330), the U-shaped internal return (311, 321, 331) of each winding element (31, 32, 33) extending in a plane orthogonal to the plane in which the first or the second tube portion (310, 312, 320, 322, 330, 332) extends, each winding element (31, 32, 33) being connected to another winding element (32, 33) by a U-shaped connecting return (313, 323) bent in the opposite direction to the direction of bending of each of the U-shaped internal returns (311, 321, 331) of the winding elements (31, 32, 33).

2. Thermodynamic heating apparatus according to Claim 1, wherein the winding elements (31, 32, 33) and the U-shaped connecting returns (313, 323) are formed by a single tube without connection, such as a weld, which is configured so as to obtain, flat, a coil (38) which, in the state applied against the tank, forms the winding elements (31, 32, 33) and the connecting returns (313, 323) between the winding elements (31, 32, 33).

3. Thermodynamic heating apparatus according to Claim 1 or 2, wherein the inlet (301) is formed by a straight tube portion which extends parallel to the longitudinal axis (A2) of the tank (2), and which is extended by the first winding element (31).

4. Thermodynamic heating apparatus according to any one of the preceding claims, wherein the outlet (399) is formed by another straight portion of the tube which extends parallel to the longitudinal axis (A2) while being further away from the longitudinal axis (A2) than the inlet (301).

5. Thermodynamic heating apparatus according to any one of the preceding claims, wherein the extruded tube is made of aluminium or copper.

6. Thermodynamic heating apparatus according to any one of the preceding claims, wherein the tube has a circular or D-shaped cross section.

7. Thermodynamic heating apparatus according to any one of the preceding claims, the winding elements (31, 32, 33) and the connecting returns (311, 321, 331) forming, in a flat configuration, a coil, called main coil, which, in the state applied against the peripheral wall of the tank (2), forms a belt, one end of which is formed by the connecting returns (311, 321, 331) located on the same first side of the coil, and the opposite end of which is formed by the returns (313, 323, 333) located on the same second side of the coil, opposite the first side.

8. Thermodynamic heating apparatus according to Claim 7, wherein the bent extruded tube of the condenser (3) also comprises an additional coil (39), the straight parts of which, in the flat configuration of the tube, are orthogonal to the straight parts of the main coil (38), the additional coil being arranged between the outlet (399) and the main coil (38), and being applicable to the bottom wall (22) of the tank considered in a vertical position in the configuration of use of the tank.

9. Thermodynamic heating apparatus according to any one of the preceding claims, wherein the thermodynamic heating apparatus comprises a holding system (5) configured to keep said portions (310, 312, 320, 322, 330, 332) of the winding elements (31, 32, 33) of the tube spaced apart from one another so as to maintain the shape of the belt.

10. Thermodynamic heating apparatus according to any one of the preceding claims, wherein the thermodynamic heating apparatus comprises clamping means (4) for bringing the ends of the belt formed by the bent extruded tube against towards one another, in order to clamp the belt against the tank (2).

11. Thermodynamic heating apparatus according to Claim 9 and Claim 10, wherein the clamping means (4) are fixed to the holding system (5).

12. Thermodynamic heating apparatus according to Claim 10 or 11, wherein the clamping means (4) comprise hooks and springs.

13. Thermodynamic heating apparatus according to any one of the preceding claims, wherein, with the tank (2) comprising a water inlet in the lower part of the tank and a water drawing-off zone in the upper part of the tank, the winding element (310) closest to the refrigerant fluid inlet (301) with respect to the other winding elements is located in the upper part of the tank.

14. Method for automatically placing a bent extruded tube of a condenser (3) on a tank (2) of a thermodynamic heating apparatus (1), said tank (2) having a longitudinal axis (A2), preferably during a production cycle on a production line of the thermodynamic heating apparatus (1), the tank being intended to be filled with liquid, for example water, and the condenser (3) being intended to heat the liquid in the tank, the method comprising the following steps: - providing, in a flat configuration, an extruded and bent tube, at least part of which is configured as a coil (38); - bringing the coil (38) against the peripheral wall (20) of the tank (2); - rotating the tank (2) and applying the coil (38) against the tank during the rotation in order to surround the tank (2) with the coil (38), such that, in the state applied against the tank, the coil (38) of the tube forms a plurality of winding elements (31, 32, 33), each winding element (31, 32, 33) comprising a first tube portion (310, 320, 330), a second tube portion (312, 322, 332) and a U-shaped return (311, 321, 331), said first tube portion (310, 320, 330) extending around part of the circumference of the tank, about the longitudinal axis (A2) of the tank (2), followed by said U-shaped return (311, 321, 331), called internal return, formed by bending the tube; the U-shaped return (311, 321, 331) being extended by said second tube portion (312, 322, 332) which develops, around part of the circumference of the tank (2), about the longitudinal axis (A2) of the tank (2), in the opposite direction to the first tube portion (310, 320, 330), the U-shaped internal return (311, 321, 331) of each winding element (31, 32, 33) extending in a plane orthogonal to the plane in which the first or the second tube portion (310, 312, 320, 322, 330, 332) extends, each winding element (31, 32, 33) being connected to another winding element (32, 33) by a U-shaped connecting return (313, 323) bent in the opposite direction to the direction of bending of each of the U-shaped internal returns of the winding elements (31, 32, 33); - fastening and / or clamping the belt formed by the coil around the tank.

15. Method according to Claim 14, wherein the coil (38) has portions of different cross sections, said portions of the coil (38) being obtained for example by assembling end to end a plurality of tube portions of different cross sections or by deformation of portions of the coil.