EP2438362B1

EP2438362B1 - Gas boiler, in particular condensation gas boiler for producing hot water

Info

Publication number: EP2438362B1
Application number: EP09787746.8A
Authority: EP
Inventors: Stefano Casiraghi; Christian Cannas
Original assignee: Elbi International SpA
Current assignee: Elbi International SpA
Priority date: 2009-06-05
Filing date: 2009-06-05
Publication date: 2015-08-19
Anticipated expiration: 2029-06-05
Also published as: ES2553758T3; EP2438362A1; PL2438362T3; WO2010140174A1

Description

TECHNICAL FIELD

The present invention relates to a gas boiler.
In particular, the present invention relates to a gas boiler of the kind defined in the preamble of claim 1, for producing hot water for warming purposes or hot sanitary water.

BACKGROUND ART

A gas boiler of that kind is disclosed in US 3 336 910 A , which discloses the preamble of claim 1.
A condensation gas boiler is disclosed in EP 1 600 708 A1 . This gas boiler has proved to be very efficient in terms of performances, however, the production costs of this gas boiler are rather high and its size exceeds the size of the ordinary gas boilers without condensation. These drawbacks limit the access to potential markets for the above-identified condensation gas boilers.

DISCLOSURE OF INVENTION

One of the objects of the present invention consists in making a gas boiler that is relatively easy to be assembled.
Another object of the present invention consists in making a gas boiler with relatively few parts to be assembled.
Still another object of the present invention consists in making a gas boiler that can be easily dismantled for maintenance purposes.
A further objet of the present invention consists in making a gas boiler of relatively small size.
According to the present invention, the above-mentioned objects are achieved by a gas boiler, in particular a condensation gas boiler, having the features defined in claim 1.
According to the invention the fume evacuation assembly and the hydraulic assembly co-operate to close the casing of the heat exchanging assembly instead of using a dedicated cover for the casing and a number of conduit connections that would be required when using a separate cover. The reduction of the number of parts of the gas boiler makes easier and faster the assembling and dismantling of the gas boiler. Furthermore, the reduction of parts makes possible to design gas boilers of smaller size.
According to a preferred embodiment of the present invention said helix is clamped by the fume evacuation assembly and the hydraulic assembly so as to keep the helix and the casing mutually aligned about an axis and form an annular gap between the helix and the casing.
As a consequence spacing members are not required to keep the helix spaced apart from casing for forming the annular gap.
In accordance with a further preferred embodiment the fume evacuation assembly comprises a first cover portion and a manifold portion integrally made so as to form a single piece preferably of polymeric moulded material.
In accordance with a still further preferred embodiment the hydraulic assembly comprises a second cover portion and circuit portion of said water circuit; wherein the second cover portion and the circuit portion are integrally made so as to form a single piece preferably of moulded polymeric material.
These solutions allow reducing the number of parts and assembling operations required in the assembling and dismantling of the gas boiler.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages will come out from the description of a non-limiting embodiment of the present invention by way of example and with reference to the accompanying, drawings, in which:

Figure 1 shows a front side perspective view, with parts removed for clarity and parts exploded, of a gas boiler in accordance with the present invention; and
Figure 2 shows a back side perspective view, with parts removed for clarity and parts exploded, of the gas boiler of figure 1.

BEST MODE FOR CARRYING OUT THE INVENTION

In Figure 1, reference numeral 1 indicates as a whole a wall-mounted condensation gas boiler for producing hot water along a water circuit C1, which, in turn, exchanges thermal energy with the sanitary water conveyed along a sanitary water circuit C2.
The gas boiler 1 comprises a frame F to be hanged to a wall, not shown. In Figure 1, it is shown a part of the back side of frame F, which, in use, is mounted parallel to the wall.
The gas boiler 1 comprises a gas combustion and premixing assembly 2 for producing thermal energy and combustion fumes; a heat exchanging assembly 3 including a casing 4 and an elongated hollow member 5 defining a portion of the water circuit C1; a fume evacuation assembly 6 for evacuating the combustion fumes from the heat exchanging assembly 3; and a hydraulic assembly 7 for controlling the flow of the water along the water circuit C1.
The premixing and combustion assembly 2 comprises a fan 8; a cylindrical burner 9; a conduit 10 connecting the fan 8 to the cylindrical burner 9; and an annular cover 11 extending about the burner 9. The parts of the premixing and combustion assembly 2 are pre-assembled together so as to form a unitary assembly that includes also ignition devices and probes, not shown in the enclosed Figures and supported by the annular wall 11.
The heat exchanging assembly 3 comprises the casing 4 with an open end, namely a back open end, and the elongated hollow member 5. The casing 4 comprises a cylindrical wall 12; and a front annular wall 13, which is joined to the cylindrical wall 12, and includes an axial sleeve 14 for supporting the elongated hollow member 5, and holes 15 for connecting the premixing and combustion assembly 2 to the heat exchanging assembly 3 by means of screws, not shown. The elongated hollow member 5 is wound, at least in part, in a cylindrical helix 16 about an axis A1 perpendicular to the back side of the frame F and to the wall, not shown. The helix 16 has a constant pitch and a constant radius, and includes a number of spaced apart turns. The elongated hollow member 5 comprises a front straight end 17 parallel to axis A1, and a back straight end 18 extending tangentially with respect to helix 16. The front straight end 17 is housed into the axial sleeve 14 of the front annular wall 13, whereas the back straight end 18 is directly coupled to the hydraulic assembly 7.
The elongated hollow element 5 comprises a tube 19 having an oval cross-section and a number of fins, not shown, parallel to the tube 19, and co-extruded with tube 19. At the front straight end 17 and at back straight end 18, the tube 19 has a circular cross-section and is deprived from fins as disclosed in the European patent application EP 1,600,708 A1 . The mutually spaced apart turns of helix 16 defines a helical gap between them, an annular gap with the cylindrical wall 12 to be travelled by the combustion fume and a cylindrical space to house the burner 9 and the combustion fumes. In order to force the combustion fumes along the helical and the annular gaps the heat exchanging assembly 3 further comprises a disc, which is not shown in the enclosed Figures, and is screwed into the helix 16 as disclosed in the European patent application EP 1,600,708 A1 .
The fume evacuation assembly 6 and the hydraulic assembly 7 are clamped onto the casing 4 at said open end in order to close the open end.
The fume evacuation assembly 6 comprises a cover portion 20 for coupling to the casing 4, and a manifold portion 21 having an upper opening for attachment to an evacuation conduit not shown in the enclosed Figures. The cover portion 20 and the manifold portion 21 are integrally made in a single piece of moulded polymeric material.
With reference to Figure 2, the manifold portion 21 is provided with a back opening shown in phantom, which is an alternative to the upper opening.
The hydraulic assembly 7 comprises a cover portion 22 to be coupled to the casing 4 and to cover portion 20, and a circuit portion 23, which are integrally made in a single piece of moulded polymeric material.
As better shown in figure 2, the cover portions 20 and 22 are suitable to be joined one another by means of flanges 24 and screws, not shown in the enclosed Figures. In other words, the fume evacuation assembly 6 and the hydraulic assembly 7 are assembled by means of flanges 24 and screws (not shown).
With reference to figure 1, the cover portions 20 and 22 once assembled form a cup shaped body, which is suitable to house an edge portion of casing 4 and a portion of helix 16, which protrudes from the edge portion of casing 4. In other words, when cover portions 20 and 22 are joined one another, the casing 4 is clamped by the cover portions 20 and 22. Furthermore, the cover portions 20 and 22 act as a spacing member for keeping the helix 16 and the casing 4 in a mutual concentric position about axis A1. To accomplish this function, cover portions 20 and 22 comprise respective clamps 25A and 25B of cylindrical shape so as to match with the external face of cylindrical wall 12, and clamps 26A and 26B of cylindrical shape, which are sized so as to match with the outer profile of the helix 16, are concentric with clamps 25A and 25B and have a smaller inner diameter than clamps 25A and 25B. Furthermore, the cover portions 20 and 22 comprise respective rest wall sections 27A, and 27B arranged transversally to axis A1 and inclined with respect to axis A1 of an angle corresponding to the inclination of the helix 16.
Rest wall sections 27A and 27B have the function of abutting against the last turn at the back side of the helix 16 to prevent the direct passage of the combustion fumes from the annular gap to the manifold portion 21.
The helix 16 is suspended to the annular front wall 13 by means of the front straight end 17 inserted in the axial sleeve 14 of the annular front wall 13, whereas is clamped between the two cover portions 20 and 22 in order to form the annular gap without the need of additional spacing members.
The hydraulic assembly 7 further comprises a pump 28 for controlling the flow of water along the water circuit C1; a three-way valve 29 for selectively directing the water along a first branch (warming branch) of water circuit C1 or a second branch (re-circulation circuit) of water circuit C1; and a plate heat-exchanger 30 for exchanging the thermal energy between the water flowing in the water circuit C1, and the sanitary water flowing in the sanitary water circuit C2.
The pump 28 comprises a pump body 31, an impeller 32, and an actuator 33. The pump body 31 is integrally made with the circuit portion 23 so as to form a single piece of moulded polymeric material, whereas the impeller 32 and the actuator 33 are assembled together to form a unit to be coupled to the circuit portion 31.
The three-way valve 29 comprises a valve body 34, a shutter 35 movable inside the valve body 34, and an actuator 36 to drive the shutter 35. The valve body 34 is integrally made with the circuit portion 23 so as to form a single piece of moulded polymeric material, whereas the shutter 35 and the actuator 36 are assembled to form a unit to be coupled to the circuit portion 23.
The plate heat exchanger 30 as shown in Figure 2 has two pipe connections 37 and 38 for the sanitary water circuit C2, and as shown in Figure 1 two pipe connections 39 and 40 to be connected to circuit portion 23.
With reference to figure 2, the circuit portion 23 comprises two pipe connections 41 and 42, which are suitable to be connected respectively to pipe connections 39 and 40, and are integrally made with the circuit portion 23 to form a single piece of moulded polymeric material.
More generally, the circuit portion 23 includes a portion of water circuit C1 extending through it, and is directly coupled to the elongated hollow member 5 by means of a pipe connector 43, which is integrally made with the circuit portion 23 so as to form a single piece of moulded polymeric material, and protrudes inside the cover portion 22.
As disclosed in the description of the preferred embodiment of the present invention it is clear that the number of parts of a heat exchanger may be reduced in a considerable extent. The reduction of parts has a positive effect in the reduction of the number of operations required for assembling and dismantling the gas boiler, and the allow designing gas boiler of smaller size.
Even though the detailed description makes reference to a wall-mounted gas boiler the present invention is applicable also to other types of gas boiler, for example floor standing gas boilers.
The present invention includes further variations not explicitly described but falling within the scope of the enclosed claims.

Claims

Gas boiler, in particular condensation gas boiler for producing hot water along a water circuit (C1); the gas boiler (1) comprising: a gas combustion and premixing assembly (2) for producing thermal energy and combustion fumes; a heat exchanging assembly (3) including a casing (4) having an open end, and an elongated hollow member (5) wound, at least in part, in a helix (16) and defining a portion of said water circuit (C1) in said casing (4); a fume evacuation assembly (6) for evacuating the combustion fumes from the heat exchanging assembly (3); and a hydraulic assembly (7) for controlling the water flow in said water circuit (C1); said casing (4) being clamped at said open end by the fume evacuation assembly (6); the gas boiler (1) being characterized in that said casing (4) is clamped at said open end by the hydraulic assembly (7), and in that the fume evacuation assembly (6) and the hydraulic assembly (7) are so shaped so as to close the open end of the casing (4).
Gas boiler according to claim 1, wherein said helix (16) is clamped by the fume evacuation assembly (6) and the hydraulic assembly (7) so as to keep the helix (16) and the casing (4) mutually aligned about an axis (A1) and to form an annular gap between the helix (16) and the casing (4).
Gas boiler according to claim 2, wherein said helix (16) slightly protrudes from the open end of the casing (4).
Gas boiler according to any one of the foregoing claims, wherein the fume evacuation assembly (6) comprises a first cover portion (20), and the hydraulic assembly (7) comprises a second cover portion (22); the first and second cover portions (20, 22) being suitable to be coupled one another.
Gas boiler according to claim 4, wherein the first and second cover portions (20, 22) comprise respective first and second clamps (25A, 25B) clamped onto the casing (4); and respective third and fourth clamps (26A, 26B) clamped onto the helix (16).
Gas boiler according to claim 5, wherein said casing (4) comprises a cylindrical wall (12) and said helix (16) has a constant diameter; the first and the second clamps (25A, 25B) being shaped so as to match with the outer surface of the cylindrical wall (12), whereas the third, and the fourth clamps (26A, 26B) being shaped so as to match with the outer profile of the helix (16) and having an inner diameter smaller than the inner diameter of the first and second clamps (25A, 25B).
Gas boiler according to claims 2 and any one of claims from 4 to 6, wherein the first and second cover portions (20, 22) comprises respective first and second rest wall sections (27A, 27B) transversal to said axis (A1) and abutting said helix (16).
Gas boiler according to any one of claims from 4 to 7, wherein said first and second cover portions (20, 22) includes flanges (24) for tightly and mutually coupling the first and second cover portions (20, 22).
Gas boiler according to any one of claims from 4 to 8, wherein the fume evacuation assembly (6) comprises a manifold portion (21) having an opening for attachment to an evacuation conduit; the first cover portion (20) and the manifold portion (21) being integrally made so as to form a single piece, preferably of polymeric material.
Gas boiler according to any one of the claims from 4 to 9, wherein the hydraulic assembly (7) comprises a circuit portion (23) defining a part of the water circuit (C1).
Gas boiler according to claim 10, wherein said second cover portion (22) and said circuit portion (23) are integrally made so as to form a single piece, preferably of polymeric material.
Gas boiler according to claim 10 or 11, wherein said hydraulic assembly (7) comprises a circulation pump (28) including a pump body (31); said circuit portion (23) and said pump body (31) being integrally made so as to form a single piece, preferably of polymeric material.
Gas boiler according to any one of claims from 10 to 12, wherein said hydraulic assembly (7) comprises a three-way valve (29) including a valve body (34); said circuit portion (23) and said valve body (31) being integrally made so as to form a single piece, preferably of polymeric material.
Gas boiler according to any one of claims from 10 to 13, wherein said hydraulic assembly (7) comprises a heat exchanger (30), preferably a plate heat exchanger, said circuit portion (23) including integrally made pipe connections (41, 43) for attachment to said heat exchanger (30).
Gas boiler according to any one of claims from 10 to 13, wherein said elongated hollow member (5) comprises a back straight end (18); said circuit portion (23) including an integrally made further pipe connection (43) for attachment to said back straight end (18) of the elongated hollow member (5).
Gas boiler according to any one of the foregoing claims, wherein said elongated hollow member (5) includes a front straight end (17), and said casing (4) including a front annular wall (13) comprising a sleeve (14) housing said front straight end (17) for supporting said elongated hollow member (5) inside said casing (4).
Gas boiler according to any one of the foregoing claims comprising a frame (F) having a back side parallel to a wall for hanging the gas boiler (1), wherein the elongated hollow member (5) is wound in a helix (16) about an axis (A1) perpendicular to the back side of the frame (F).