CN109477702B

CN109477702B - High-efficiency heating device

Info

Publication number: CN109477702B
Application number: CN201780035804.7A
Authority: CN
Inventors: 奥兰多·尼博利
Original assignee: Fondital SpA
Current assignee: Fondital SpA
Priority date: 2016-06-07
Filing date: 2017-06-07
Publication date: 2021-03-12
Anticipated expiration: 2037-06-07
Also published as: EA037896B1; EA201892594A1; ITUA20164170A1; CN109477702A; WO2017212415A1; EP3465060A1

Abstract

A high efficiency heating apparatus having: a body comprising an inner cavity in which a heating liquid circulates; a connector in communication with the cavity and extending from the body; and a front plate having an outer face which, in use, faces the heating space and defines a primary front heat exchange surface of the device; the cavity is delimited by a pair of main walls facing each other and by a closed-loop perimetric edge connecting the main walls; the cavity has a surface to volume ratio, denoted dm2 and dm3, respectively, of greater than or equal to 23.

Description

High-efficiency heating device

Technical Field

The invention relates to a high-efficiency heating device.

Background

A common indoor heating system consists of a radiator in which a heated liquid (usually hot water) circulates.

The heat sinks used in these systems can be made of various metallic materials and are typically formed from batteries (batteries) of heat sink elements that are manufactured separately and then joined together.

A typical radiator element has a substantially tubular body provided with an internal cavity through which water flows (water chamber) and has hydraulic connections for connection to other similar radiator elements and/or hydraulic circuits and arranged at opposite ends of the element; two opposed baffles extend from the water chamber along the centerline plane of the element, supporting the front and rear plates, respectively; a plurality of heat exchange fins extend from the tubular body.

Heat sinks comprising these elements are generally considered to be entirely satisfactory and have now reached the limits of their performance and can be improved no further, or at least only minimally, in particular in terms of their specific power per unit weight, i.e. the ratio between the thermal power emitted by the heat sink element and transferred to the environment (measured according to a specific standard, for example EN 442) and the weight of the element (which is a fundamental parameter directly affecting the production costs).

However, the inventors of the invention in question have determined that with the known solutions there is still significant room for improvement, in particular in terms of specific power, and generally in terms of efficiency: even with good specific power, known radiators generally require a relatively high operating temperature (temperature of the water supplied to the radiator).

On the other hand, it is generally recognized that a possible solution to the problem of increasing the power of the radiator is to increase the amount of water circulating in the radiator, i.e. to increase the volume of the water chamber.

In contrast, the inventors of the discussed invention have found that the water used in the heat exchange is actually only water that floods the walls of the water chamber, so that increasing the water content (i.e. the volume of the water chamber) does not necessarily lead to an increase in thermal power.

Disclosure of Invention

It is therefore an object of the present invention to provide a heating device, in particular made of aluminum, which can also be used in place of a conventional radiator or radiator element and has a high thermal efficiency.

The heating device according to the invention thus overcomes the technical problem of the limited power of the radiators known in the prior art. Compared to conventional methods, according to the present invention the technical problem has been overcome by increasing the contact surface between water (heating liquid) and metal (wall of the water chamber), but without limiting the space available for the convective movement of air over the rest of the heating device, and thus limiting the total volume of the water chamber. The inventors of the discussed invention have realized that in order to increase power and overall efficiency, the heat exchange between water and metal must be improved, since the only water actually used in the heat exchange is the water that floods the wall of the water chamber.

Thus, according to the invention, it is desirable to increase the exchange surface and alternatively reduce the amount of water, i.e. the volume of the water chamber, but without hindering the convective movement of the water in the chamber.

Therefore, according to the invention, the water chamber must be designed such that the ratio between the surface and the volume is greater than a minimum threshold.

Furthermore, this innovative method allows the speed of the water circulation to be increased and allows the flow conditions to change from laminar to turbulent, thus further increasing the already larger heat exchange surface.

The result is a particularly efficient heating device which in particular enables the heat from the heating liquid to be utilized to its full extent and at the same time provides sufficient resistance from a structural point of view.

Basically, the device according to the invention is designed such that the water chamber has a large heat exchange surface but a relatively small volume: the volume occupied by the heated liquid (water) is therefore reduced, but in practice all the water exchanges heat with the walls defining the cavity in the cavity, thus increasing the overall heat exchange capacity. Furthermore, since the water is separated from the walls of the cavity by the additional layer of water at a lower temperature, the formation of zones in the cavity is prevented, wherein the water is kept at a high temperature and is not substantially released to the walls of the cavity.

In this way, the device according to the invention achieves a high level of efficiency and can be operated even at relatively low water temperatures.

The auxiliary heat exchange surfaces extend directly from the wall of the water chamber and these heat exchange surfaces also utilize all the heat from the heating liquid.

The optional addition of auxiliary parts and components (such as turbulators or other elements to deflect or convey the water flow; tie-downs to increase mechanical strength, etc.) within the chamber further improves efficiency, as the presence of such additional elements also helps to reduce the amount of water available and increase the heat exchange surface available for the water.

Drawings

Further features and advantages of the invention will become apparent from the following description of non-limiting embodiments thereof, with reference to the accompanying drawings, in which:

fig. 1 is a perspective view of a first embodiment of a heating device according to the invention;

FIG. 2 is a side view of the device of FIG. 1;

FIGS. 3 and 4 are two cross-sectional views taken along the dashed lines III-III and IV-IV, respectively, in FIG. 2;

FIG. 5 is a perspective view of a second embodiment of a heating device according to the present invention;

fig. 6 and 7 are a longitudinal sectional view and a cross-sectional view, respectively, of the heating device of fig. 5.

Detailed Description

In fig. 1 and 2, a heating device (for a heating environment inside a building) of the hydronic (for example, hot water) type is indicated as a whole by the reference numeral 1.

The device 1 comprises a body 2 made of a heat-conducting material, for example, but not necessarily, a metallic material, in particular aluminium (the term also including aluminium alloys, i.e. alloys containing aluminium), as well as aluminium obtained, for example, by die casting (i.e. made of aluminium or an aluminium-containing alloy produced by a die casting process). It should be understood that the body 2 may be made of another material, as long as it is suitable for conducting heat (such as ceramics, polymers, composites and other materials), and produced by other production processes (e.g., by an extrusion process).

Referring also to fig. 3 and 4, the body 2 is a hollow body and is provided with an inner cavity 3 (water chamber) in which a heating liquid (e.g. hot water) circulates when in use.

The body 2 comprises a front heat exchange plate 4 and a rear heat exchange plate 5, the front heat exchange plate 4 and the rear heat exchange plate 5 being positioned at respective opposite ends of the body 2 (precisely, with reference to the normal position of use of the device 1, front and rear ends) and being joined substantially facing each other and along respective peripheral edges 6, the respective peripheral edges 6 together forming a closed-loop peripheral edge 7 of the cavity 3.

In the example shown in fig. 1 to 4, the

plates

4, 5 have a substantially quadrangular shape (for example substantially square or rectangular), but it should be understood that the

plates

4, 5 may have different shapes.

The front plate 4 has an inner face 8, the inner face 8 facing the cavity 3 and being wetted by the heating liquid and thus exchanging heat with (receiving heat from) the heating liquid in the cavity 3; and an outer face 9, the outer face 9 being opposite the inner face 8 and defining a first heat exchange surface 10 (in particular the main front heat exchange surface of the device 1), the first heat exchange surface 10 facing, in use, the environment to be heated and exchanging heat with (releasing heat into) the air in the environment in which the device 1 is installed, in addition to releasing heat into the environment by radiation.

Also, the rear panel 5 has an inner face 11, the inner face 11 facing the cavity 3 and being wetted by the heating liquid and thus exchanging heat with (receiving heat from) the heating liquid in the cavity 3; an outer face 12, the outer face 12 being opposite the inner face 11 and defining a second heat exchange surface 13, the second heat exchange surface 13 facing, in use, a support wall W to which the device 1 is fixed by fastening means (of a type known and not shown here for the sake of simplicity) and exchanging heat with the air (releasing the heat into the air) in the environment in which the device 1 is installed.

The surface 10 defines the main front heat exchange surface of the device 1, facing the environment to be heated and opposite the support wall W to which the device 1 is fixed.

The cavity 3 extends along a longitudinal axis a, which is vertical in use, and a transverse axis B, which is horizontal in use, defining the height and width of the cavity 3, respectively; and extends along a third axis C perpendicular to the longitudinal axis a and the transverse axis B and defines the thickness of the cavity 3.

The cavity 3 is frontally delimited by the front plate 4 and precisely by an inner face 8 of the front plate 4 facing the cavity 3; and is delimited posteriorly by the backplate 5 and precisely by the inner face 11 of the backplate 5 facing the inner face 8 of the front plate 4.

The inner face 8 of the front plate 4 and the inner face 11 of the rear plate 5 face each other and are spaced apart such that the distance between them defines the thickness of the cavity 3.

The thickness of the cavity 3 is therefore defined as the distance between the front plate 4 and the rear plate 5 and precisely between the inner face 8 of the front plate 4 and the inner face 11 of the rear plate 5.

As shown in fig. 1 to 4, the

plates

4, 5 are not necessarily planar and parallel, but may have different shapes and may be arranged differently: for example, one or both of the

plates

4, 5 may be curved, corrugated, etc.; and/or the

plates

4, 5 may be inclined towards each other. The cavity 3 may also have a variable (different) thickness (measured parallel to the axis C) along the longitudinal axis a and/or along the transverse axis B.

Preferably, as shown, the cavity 3 is a thin cavity, the thickness of which is small relative to the other dimensions (height and width) and relative to at least one from among the height and width (in at least one or more portions of the cavity 3 if not in the entire cavity 3).

In particular, in the embodiment shown (although not necessarily), the cavity 3 has a substantially flat shape and extends mainly along a longitudinal axis a, which is vertical in use, and along a transverse axis B, which is horizontal in use, defining the height and width, respectively, of the cavity 3; and the cavity 3 has a thickness measured perpendicular to the longitudinal axis a (vertical in use) and to the transverse axis B (horizontal in use), i.e. along an axis C (perpendicular to the longitudinal axis a and to the axis C) smaller than the height and width.

For example, the cavity 3 has a maximum thickness (thus considering the maximum thickness of the cavity 3 if the cavity 3 has different thicknesses in different regions of the cavity 3) which is at least 20 times, preferably 30 times, more preferably 40 times smaller than each lateral dimension (measured in a direction perpendicular to the thickness) of the front plate 4, i.e. the height and width.

Thus, with reference to the normal position of use of the device 1 (meaning the position in which the front plate 4 is substantially vertical and faces the environment to be heated), the cavity 3 has a height and a width, each of which is at least 20 times greater, preferably at least 30 times greater, even more preferably at least 40 times greater than the thickness of the cavity 3.

In the example shown in fig. 1 to 4, the cavity 3 extends over substantially the entire front plate 4, except that the peripheral edge 6 of the front plate 4 is joined to the corresponding peripheral edge 6 of the rear plate 5.

In particular, the cavity 3 extends over at least 60% of the front plate 4: at least 60% of the surface of the front plate 4 facing the inner face 8 of the cavity 3 thus faces the cavity 3.

In other words, the cavity 3 occupies at least 60% of the inner face 8 of the front plate 4, i.e. the cavity 3 has a surface in contact with the inner face 8 of the front plate 4 which is at least 60% of the entire surface of the inner face 8 of the front plate 4 (meaning the surface of the cavity 3 defined on the inner face 8 of the front plate 4 from the peripheral edge and thus excluding any space within the cavity 3 occupied by internal elements such as gaskets, ribs, structural reinforcements, flow conveyors and the like, which will be described later).

In other embodiments, the cavity 3 extends over at least 65%, or at least 70%, or at least 75% or at least 80%, or at least 85%, or at least 90% of the inner face 8 of the front panel 4.

The body 2 is further provided with a connector 16, the connector 16 extending from one or both of the

plates

4, 5 and communicating with the cavity 3.

In the example of fig. 1 to 4, in particular, the connection 16 projects from the rear plate 5 and precisely from the outer face 12 of the rear plate 5 and is substantially perpendicular to the rear plate 5 and substantially perpendicular to the outer face 12 of the rear plate 5.

In the example shown, the device 1 has four connections 16 positioned at respective corners of the cavity 3. It should be understood, however, that the body 2 may be provided with a different number of connecting pieces 16, the connecting pieces 16 also being arranged at other positions, not necessarily at the corners of the cavity 3. Preferably, but not necessarily, the connecting element 16 is positioned along the peripheral edge 7 of the cavity 3.

The connections 16 are defined by respective sleeves, for example, but not necessarily, substantially cylindrical (although the sleeves may also have different shapes), and their purpose is to connect the device 1 to an external hydraulic circuit (not shown) and/or to connect the device 1 to other identical devices to define a modular system (as described later in this document).

The connections 16 not used to connect the device 1 to another identical device to define a modular system or to connect the device 1 to an external hydraulic circuit are closed by plugs (not shown).

In general, the chamber 3 has at least one inlet 16a and one outlet 16b defined by respective connections 16.

In the example shown, the front plate 4 and the rear plate 5 are both substantially planar and parallel; it should be understood that the front panel 4 and/or the rear panel 5, like their faces, may have different shapes, such as curved, corrugated, etc.

The outer face 9 of the front plate 4 is for example substantially smooth.

In the embodiment shown in fig. 1 to 4, the rear plate 5 supports a plurality of heat exchange fins 17, the heat exchange fins 17 extending from the rear plate 5 to outside the chamber 3 and precisely from the outer face 12 of the rear plate 5.

In the non-limiting example shown, the fins 17 are substantially perpendicular to the outer face 12 of the rear plate 5 and parallel to each other and to the longitudinal axis a (vertical in use). It should be understood that the fins 17 may be formed and arranged differently, i.e. the fins 17 may have a different shape than what is shown merely as an example, they may be oriented in a different way, arranged differently with respect to each other.

Preferably, as shown in fig. 1 to 4, all the fins 17 extend directly from the cavity 3, since they are directly joined to the wetted wall 18 of the cavity 3, in this case defined by the rear plate 5, so that all the fins 17 are so-called "wetted fins". All fins 17 have a root edge 19 joined to the wetted wall 18 of the cavity 3, which is in direct contact with the heating liquid.

The front plate 4 and the rear plate 5 comprise or constitute respective

main walls

24, 25 of the cavity 3, wherein respective

inner surfaces

26, 27 face the cavity 3 and are wetted by the heating liquid contained in the cavity 3.

The term "main wall" refers to the wall of the cavity 3 (i.e. the wall defining the cavity 3 and directly in contact with the heating liquid contained in the cavity 3) which has a greater surface extension (area) than each of the other walls of the cavity 3.

The front plate 4 and the rear plate 5 thus comprise or constitute the

main walls

24, 25 of the cavity 3, and precisely the front wall 24 and the rear wall 25, the front wall 24 facing, in use, the environment to be heated, and the rear wall 25 facing, in use, the wall W of the environment to be heated. The inner faces 8, 11 of the

plates

4, 5 define (or comprise) the

inner surfaces

26, 27 of the

main walls

24, 25.

The cavity 3 is delimited by two

main walls

24, 25, the

main walls

24, 25 facing each other and being defined by the

plates

4, 5 in the embodiment shown in fig. 1 to 4; and by the peripheral edge 7 connecting the

main walls

24, 25 to each other and having an extension (surface) smaller than each of the

main walls

24, 25.

The cavity 3 has a substantially flat shape.

In particular, cavity 3 has a ratio between surface and volume, denoted dm2 and dm3, respectively, greater than or equal to 23; preferably, the ratio is greater than or equal to 33, or greater than or equal to 36, or greater than or equal to 40, or greater than or equal to 50.

Furthermore, the cavity 3 has a surface of at least 2dm 2.

The cavity 3 has, in a cross section perpendicular to the longitudinal axis a, a ratio between width and depth greater than or equal to 20 and preferably greater than or equal to 30, more preferably greater than or equal to 40.

The width in the cross section of the cavity 3 is defined as the maximum distance measured between opposite portions of the edge 7 in a cross section parallel to the transverse axis B; and the depth in the cross section of the cavity 3 is defined as the maximum distance measured in a cross section parallel to the axis C between the

main walls

24, 25 and precisely between the respective inner faces of the

main walls

24, 25.

In the embodiment shown in fig. 1 to 4, the

main walls

24, 25 are substantially parallel to the main front heat exchange surface 10 of the device 1.

The front plate 4 and the rear plate 5, comprising the

main walls

24, 25 of the cavity 3 and the respective peripheral edges 6 shaped to couple with each other, are advantageously formed by respective single pieces, for example made of aluminium obtained by a die-casting process; the two pieces constituting the two

plates

4, 5 are then joined along the respective peripheral edges 6 so as to form a mechanical and fluid-tight joint.

Advantageously, the

plates

4, 5 are joined by a thermoelectric melting process, carried out by circulating an electric current through the respective contact portions of the pieces to be joined to cause their local melting, without the action of a welding material (as described in international patent application WO 2014/155295).

However, the

plates

4, 5 can be joined in other ways, for example by mechanical joining methods (possibly with interposition of sealing gaskets), gluing, other types of welding (not necessarily electromagnetic), etc.

Advantageously, the fins 17 are made as integral parts of the plate 5 from which they protrude so as to form a single piece therewith (i.e. the fins are not carried by the plate 5 or joined to the plate 5, but are made directly from the plate 5, for example in an extrusion or die-casting step).

Inside the cavity 3 there are tie-rods 33, i.e. protrusions extending between the front plate 4 and the rear plate 5 (i.e. between the main walls 24, 25), and integral (firmly joined to or made in one piece with) the inner face 8 of the front plate 4 and the inner face 11 of the rear plate 5, i.e. with the respective inner faces of the

main walls

24, 25 facing the cavity 3.

In the example shown, the tie-rods 33 are made in a single piece with one of the

panels

4, 5 and extend towards the opposite panel to which they are joined, for example by welding or thermowelding (although it should be understood that, as already mentioned, the

panels

4, 5 may be joined to each other in other ways), when the

panels

4, 5 are joined to each other to form the device 1, in particular by a local thermo-electric melting process on each tie-rod 33; specifically, the tie bars 33 are shaped as protrusions on the inner face 11 of the rear panel 5 (and are manufactured, for example, by die casting from the panel 5) and are welded to the inner face 8 of the front panel 4. Alternatively, the tie-rods 33 may be manufactured separately and welded to the two

plates

4, 5; or even made as an integral part of both

plates

4, 5.

Basically, the tie-rods 33 can be defined directly as an integral part of the two

plates

4, 5, according to the technique used in the production of the body 2; or as an integral part of one of the

plates

4, 5 which is then joined (welded) to the other plate; or as a separate component which is later joined (welded) to the two

plates

4, 5.

The tie bars 33 are distributed over the

faces

8, 11 and their main function is to increase the mechanical strength of the device 1, in particular to improve its resistance to compression. The tie rods 33 also help to make the device 1 fluid-tight, since they help to keep the two

plates

4, 5 joined together, so as to prevent any liquid leakage.

Since the tie rods 33 are inserted along the path of the heating liquid in the chamber 3, they also have the function of distributing the heating liquid in the chamber 3.

In general, advantageously, but not necessarily, the cavity 3 houses between the two

plates

4, 5 an internal element 34 (which may also comprise a tie rod 33), said internal element 34 acting on the flow of the heating liquid circulating in the cavity 3, for example to define one or more paths in the cavity 3, to distribute the heating liquid in the cavity 3, to modify the movement of the heating liquid in the cavity 3, etc.

In particular, the elements 34 (or at least some of the elements 34) are shaped and arranged so as to contribute to an even distribution of water in the cavity 3.

In the preferred embodiment shown in fig. 4, the element 34 comprises, in addition to the tie-rods 33, a first distributor 35a positioned at the top end 36a of the chamber 3 and/or a second distributor 35b positioned at the bottom end 36b of the chamber 3 (again with reference to the normal use position of the device 1: the

ends

36a, 36b are axially opposite ends with respect to the longitudinal axis a).

The distributors 35a, 35B are defined by respective transverse walls, for example substantially parallel to the transverse axis B (or inclined with respect to the latter, or curved or even shaped differently), which extend between the inner face 8 of the front plate 4 and the inner face 11 of the rear plate 5 and between the two laterally opposite sides of the cavity 3, and are provided with respective series of longitudinally spaced through holes 37. The distributor 35a is positioned close to and below the inlet 16a, the inlet 16a being defined by one of the sleeves 16 and being positioned at the top end 36a of the chamber 3. The distributor 35a is positioned close to the inlet 16a and below the inlet 16a, the inlet 16a being defined by the first connection 16 positioned at the top end 36a of the chamber 3; and a distributor 35b is positioned close to and above the at least one outlet 16b, which outlet 16b is defined by another connection 16 positioned at the bottom end 36b of the chamber 3.

In the preferred embodiment shown in fig. 4, the chamber 3 has an inlet 16a, the inlet 16a being defined by a first connector 16 positioned at the top end of the chamber 3; and two outlets 16b, the outlets 16b being defined by respective further connections 16 positioned at the bottom end of the chamber 3 and at respective opposite lateral ends of the chamber 3. In use, thanks to the

distributors

35a, 35b, the heating liquid, after being substantially uniformly distributed inside the cavity, enters the cavity 3 through the inlet 16a and exits through the two outlets 16 b.

The chamber 3 may also accommodate only one of the

distributors

35a, 35 b. The shape of the

distributors

35a, 35b may also differ from the shape shown and described here purely by way of example.

The presence of the tie-rods 33, and generally of the elements 34 and any other auxiliary components inside the chamber 3, contributes to reducing the volume available for water and to increasing the heat exchange surface available for water, further increasing the efficiency of the device 1.

Fig. 5 to 7 show a second embodiment of the heating device 1 according to the invention, wherein details similar or identical to those already described are denoted by the same reference numerals.

Also in this embodiment, the device 1 comprises a body 2 made of a heat-conducting material (for example aluminium), the body 2 being provided with an inner cavity 3 (water cavity), through which inner cavity 3, in use, heated liquid (hot water) circulates.

In this case, the body 2 is configured to replace a conventional heat sink element to form a battery of heat sink elements arranged side by side.

The cavity 3 has a substantially flat shape and is mainly elongated along a longitudinal axis a, which is vertical in use, and a transverse axis B, which is horizontal in use, longitudinally, defining the height and width, respectively, of the cavity 3.

The cavity 3 has a height and a width measured along a longitudinal axis a (vertical in use) and a transverse axis B (horizontal in use), respectively, and a thickness measured along an axis C (horizontal in use) perpendicular to the longitudinal axis a and the transverse axis B.

The cavity is again delimited by a pair of opposite

main walls

24, 25 facing each other and by a peripheral edge 7, which connects the

main walls

24, 25 to each other and has a smaller surface than each of the

main walls

24, 25.

Also according to this embodiment, the cavity 3 has a substantially flat shape, as described above.

Furthermore, the cavity 3 has a surface of at least 2dm 2.

The cavity 3 has, in a cross section perpendicular to the longitudinal axis a, a ratio between width and depth (again as measured by the maximum distance in cross section between the opposite portions of the edge 7 and respectively between the main walls 24, 25) greater than or equal to 20 and preferably greater than or equal to 30, more preferably greater than or equal to 40.

Also according to this embodiment, the cavity 3 extends mainly in height and width along the longitudinal axis a and the transverse axis B, respectively; and has a thickness measured along an axis C perpendicular to the longitudinal axis a and the transverse axis B that is substantially less than the height and the width.

The thickness of the cavity 3 is again defined as the distance between the

main walls

24, 25, and precisely between the respective

inner surfaces

26, 27 of the main walls 24, 25 (thus measured along the axis C).

But now the

main walls

24, 25 are substantially perpendicular to the main front heat exchange surface 10 of the device 1 (and not substantially parallel to the surface 10 as in the embodiment described with reference to figures 1 to 4).

In other words, the

main walls

24, 25 define respective lateral sides of the device 1, with reference to the normal position of use of the device 1.

The surface 10 consists of the outer face 9 of the front plate 4 protruding from the peripheral edge 7 of the cavity 3.

In particular, the plate 4 is joined to the front portion 28a of the peripheral edge 7 of the cavity 3.

In the example shown in fig. 7, the panel 4 is joined to the edge 7 by a longitudinal seam 29 (parallel to the longitudinal axis a) and extends on opposite sides of the seam 29.

Optionally, the body 2 further comprises a rear plate 5, the rear plate 5 extending from a rear portion 28b of the peripheral edge 7 of the cavity 3.

As with panel 4, panel 5 is also joined to edge 7, for example by a longitudinal seam 29 (parallel to longitudinal axis a).

Preferably, the plates 4 and/or 5 are in direct contact, completely or at least partially, with the heating liquid contained in the chamber 3, i.e. they have at least respective wall portions delimiting the chamber 3, forming respective portions of the edge 7 of the chamber 3. In this way, the plates 4 and/or 5 are also so-called "wet fins".

In addition to the

plates

4, 5, the device 1 also comprises a heat exchange surface defined by a plurality of heat exchange fins 17, said plurality of heat exchange fins 17 extending from the

main walls

24, 25 to the outside of the chamber 3.

In the non-limiting example shown, the fins 17 are substantially perpendicular to the

main walls

24, 25 and parallel to each other and to the longitudinal axis a (vertical in use). It should be understood that the fins 17 may be formed and arranged differently.

Preferably, also in this case, all the fins 17 extend directly from the chamber 3, since they are directly joined to the wet wall 18 of the chamber 3, which is defined in this case by said

main walls

24, 25 of the chamber 3, so that all the fins 17 are "wet fins".

The connectors 16 are arranged in pairs at respective opposite longitudinal ends (located along the longitudinal axis a), respectively a top end and a bottom end of the body 2 in use.

The connecting piece 16 extends from both

walls

24, 25 and is substantially perpendicular to the

walls

24, 25; the connectors 16 positioned at the same longitudinal ends are parallel to each other parallel to the axis C.

Also in the embodiment shown in fig. 5 to 7, the body 2 is advantageously (but not necessarily) formed by two single pieces, each comprising one of the

main walls

24, 25 and the respective peripheral edge 6.

The peripheral edges 6 are shaped to couple to each other to form a peripheral edge 7 of the cavity 3.

The piece comprising the

main walls

24, 25 and the respective peripheral edge 6 is for example made of aluminium obtained by die-casting and is advantageously joined along the respective peripheral edge 6 by the thermoelectric melting process previously described, so as to form a mechanically and fluid-tight joint.

Although not shown for the sake of simplicity, in the embodiment shown in fig. 5 to 7, the chamber 3 can house a tie-rod 33, the tie-rod 33 being arranged between the

main walls

24, 25 and being firmly joined to the two

inner surfaces

26, 27 of the

main walls

24, 25; and/or other internal elements acting on the flow of the heating liquid circulating in the cavity 3 and shaped and/or arranged so as to contribute to an even distribution of the heating liquid in the cavity 3.

Finally, it should be understood that further modifications and variations can be made to the heating device described and illustrated herein without departing from the scope of the present invention as set forth in the appended claims.

Claims

1. A high efficiency heating device (1) having: a body (2) comprising an internal cavity (3) extending along a longitudinal axis (A) which is substantially vertical in use and in which a heating liquid circulates; a connector (16) communicating with the cavity (3) and extending from the body (2); and a front plate (4) having an outer face (9) facing, in use, a heating space and defining a main front heat exchange surface (10) of the device (1); said cavity (3) being delimited by a pair of main walls (24, 25) facing each other and by a peripheral edge (7) connecting these main walls (24, 25); said main walls (24, 25) being defined by respective planar and parallel plates (4, 5) having respective inner surfaces (8, 11) spaced apart such that the distance between them defines the thickness of said cavity (3), said device (1) being characterized in that said cavity (3) has a ratio between surface and volume, denoted dm2 and dm3 respectively, greater than or equal to 23; the body (2) supports heat exchange fins (17) projecting from the body (2) outside the chamber (3).

2. The device according to claim 1, wherein said cavity (3) has a surface to volume ratio, denoted dm2 and dm3, respectively, greater than or equal to 33.

3. Device according to claim 1, wherein said cavity (3) has a surface of at least 2dm 2.

4. The device according to claim 1, wherein the cavity (3) has a ratio between width and depth greater than or equal to 20 in a cross section perpendicular to the longitudinal axis (a).

5. Device according to claim 1, wherein the main walls (24, 25) of the cavity (3) are substantially parallel to the main front heat exchange surface (10) of the device (1).

6. A device according to claim 5, wherein one of the main walls (24, 25) of the cavity (3) is a front wall (24) of the cavity (3) facing, in use, the heating space; and the front plate (4) comprises or consists of the front wall (24) of the cavity (3).

7. The device according to claim 1, wherein the main walls (24, 25) are perpendicular to the main front heat exchange surface (10) of the device (1).

8. The device according to claim 7, wherein said main walls (24, 25) define respective lateral sides of said cavity (3) perpendicular to said front plate (4).

9. Device according to claim 1, wherein the body (2) is formed by two single pieces joined along respective peripheral edges (6), each single piece comprising one of the main walls (24, 25) of the cavity (3).

10. The device according to claim 1, wherein inside the cavity (3) there is a tie rod (33) which extends between the opposite main walls (24, 25) of the cavity (3) and is integral with the respective inner surfaces (26, 27) of the two main walls (24, 25).

11. Device according to claim 10, wherein said tie-rod (33) is integrally joined to said main walls (24, 25) of said chamber (3), made in one piece, or welded and/or fused with said main walls (24, 25).

12. Device according to claim 1, wherein said cavity (3) houses, between the two plates (4, 5), an internal element (34) which acts on the flow of heated liquid circulating in said cavity (3) and which is shaped and/or arranged so as to contribute to the uniform distribution of said heated liquid in said cavity (3).

13. The device according to claim 12, wherein said element (34) comprises a first distributor (35a) positioned at a top end (36a) of said cavity (3) and/or a second distributor (35b) positioned at a bottom end (36b) of said cavity (3).

14. The device according to claim 2, wherein said cavity (3) has a surface to volume ratio, denoted dm2 and dm3, respectively, greater than or equal to 36.

15. The device according to claim 14, wherein said cavity (3) has a surface to volume ratio, denoted dm2 and dm3, respectively, greater than or equal to 40.

16. The device according to claim 15, wherein said cavity (3) has a surface to volume ratio, denoted dm2 and dm3, respectively, greater than or equal to 50.

17. The device according to claim 4, wherein the cavity (3) has a ratio between width and depth greater than or equal to 30 in a cross section perpendicular to the longitudinal axis (A).

18. Device according to claim 17, wherein said cavity (3) has, in a cross section perpendicular to said longitudinal axis (a), a ratio between width and depth greater than or equal to 40.