WO2007142529A1

WO2007142529A1 - Heat exchanger and heating apparatus provided therewith

Info

Publication number: WO2007142529A1
Application number: PCT/NL2007/050273
Authority: WO
Inventors: Johannes Clemens Beukers
Original assignee: Aluheat BV; Bekaert Combustion Technology BV
Current assignee: Aluheat BV; Bekaert Combustion Technology BV
Priority date: 2006-06-08
Filing date: 2007-06-08
Publication date: 2007-12-13
Anticipated expiration: 2008-12-08
Also published as: CN101460785A; EP2032909A1

Abstract

A heat exchanger, provided with a body with at least one flue gas channel and at least one water carrying channel and a burner, wherein the body comprises at least a first and a second body part, which body parts each comprise at least a first part which is of meandering design, which body parts are positioned relative to each other in a manner such that the meandering parts engage each other at least partly and therebetween a first part of the flue gas channel is formed, while each body part comprises at least a part of the at least one water carrying channel.

Description

Title: Heat exchanger and heating apparatus provided therewith.

The invention relates to a heat exchanger.

It is known from practice to manufacture heat exchangers for, for instance, heating apparatus, hot water supplies and the like from, for instance, steel or iron or light metal such as aluminum. As a rule, a casting method is applied here. Use of steel or iron leads to relatively large and heavy heat exchangers. Casting techniques offer a relatively large design choice but complex casting moulds. For the production of a heat exchanger, the skilled person will always select a suitable material and manufacturing technique.

The object of the invention is to provide a heat exchanger. In a first aspect, a heat exchanger according to the invention is characterized in that a body is provided with at least one flue gas channel and at least one water carrying channel and a burner chamber, wherein the body comprises at least a first and a second body part. The body parts each comprise at least a first part having a meandering configuration, which body parts are positioned relative to each other such that the meandering parts engage each other at least partly, and therebetween a first part of the flue gas channel is formed, while each body part comprises at least a portion of the at least one water carrying channel.

In this specification, meandering is understood to include at least, but not exclusively, a configuration such that the part of the flue gas channel that is formed between the two body parts comprises a number of bends between a flue gas supply end and a flue gas discharge end.

In a second aspect, a heat exchanger according to the invention is characterized in that body parts are provided that are manufactured at least through extrusion, preferably from light metal such as aluminum or an alloy thereof.

In a third aspect, the invention is characterized in that at least one, and preferably each body part is provided with recesses, in particular on a side remote from the flue gas channel, in which parts of a second water-carrying channel are formed or included.

Such a second water carrying channel offers the advantage that water for a first heating circuit as well as for a second heating circuit can be heated with the heat exchanger of such design. The first heating circuit can, for instance, be a space heating circuit, the second a tap water circuit. The two water channels can be completely separated, so that they can be utilized independently from each other, without the use of, for instance, a three-way valve as is utilized with an indirectly heated hot water boiler. Like the first water channel, the second water channel can be a directly connected and heated pipe.

The aspects mentioned and other aspects of the invention can be utilized both separately and in combination.

In an advantageous embodiment, a second water carrying channel is secured, in particular clamped, for instance by pressing in, in the recesses, manufactured from, for instance, a different material than the material of the heat exchanger, at least the body parts thereof. For instance copper or a copper alloy can be utilized. With it, it can be ensured that the second water carrying channel can be used for tapping water suitable for consumption, also when the material of the body parts, such as aluminum or an alloy thereof, is less suitable for such use.

The invention further contemplates providing a body part for such a heat exchanger.

The invention furthermore contemplates providing a method for the manufacture of a heat exchanger.

In a first aspect, a method is characterized in that at least two body parts are formed, in particular through extrusion, which body parts have at least a first part with a meandering configuration, and each comprise at least one portion of a water carrying channel part, which body parts are mutually connected by sealing parts in a manner such that the body parts are thus held at a mutual distance from each other while forming a flue gas channel, and the water carrying channel parts in the two body parts are mutually connected.

The invention will be further elucidated on the basis of exemplary embodiments, with reference to the drawing. In the drawing: Figs. IA and B show, in front and side view, a heat exchanger without side parts;

Fig. 2 shows, in perspective view, a heat exchanger according to Fig. 1;

Fig. 2A shows, slightly enlarged, a portion of a heat exchanger according to Fig. 2;

Figs. 3A and B show, in front and side view, the heat exchanger, in a second embodiment, without side parts;

Fig. 4 shows, in perspective view, a heat exchanger according to Fig. 3; Fig. 4A shows, slightly enlarged, a portion of the heat exchanger according to Fig. 4;

Fig. 5 shows, in perspective view, a body part for a heat exchanger according to Figs 1 - 2;

Fig. 6 shows, in perspective view, a body part for a heat exchanger according to Figs. 3 - 4;

Fig. 7 shows, in side view, an alternative embodiment of a heat exchanger according to Fig. 1; and

Fig. 8 schematically shows a heating apparatus with a heat exchanger, in particular according to Fig. 7. The invention is described on the basis of a number of exemplary embodiments thereof. These should not be construed to be limitative in any manner. In particular, also, combinations of parts of the embodiments shown and separate parts thereof are understood to fall within the invention. Furthermore, variations thereon are understood to be also represented herein. In Fig. 1, in side view (left hand side) and front view (right hand side) a body 2 of a heat exchanger 1 is shown, assembled from two body- parts 3, 4 and a burner hood 5 with burner deck 6. The body parts 3, 4, and preferably also the burner hood 5 are preferably manufactured from, aluminum or an alloy thereof, although they can also be manufactured from a different material, such as iron or steel. In an advantageous embodiment, the body parts 3, 4 are manufactured substantially through extrusion. This is a simple and relatively inexpensive manner of manufacture. However, casting is also an option. The body parts 3, 4 each have a substantially constant cross-section in one direction, in Figs. IA and 3A at right angles to the plane of the drawing. In Fig. 1, adjacent a first end 7 of the body 2, the burner hood 5 is secured for instance by screws 8, while the burner deck 6 is confined between the burner hood 5 and two flanges 9 extending in two directions at the end 7. Optionally, a suitable gasket (not shown) may have been inserted for a flue gas-tight sealing. In the burner hood 5, a central opening 10 is provided, through which, during use, gas or a gas/air mixture can be introduced to be burned, so that heated flue gases are obtained, formed in a flue gas channel 11 between the two body parts 3, 4 as will be described hereinafter.

In this embodiment, the body 2, in particular the body parts 3, 4 each comprise a first part 12 and a second part 13, which here, link up with each other. Viewed in side view as in Fig. IA, the first part 12 has a meandering configuration. To that end, each of the body parts 3, 4 comprises a series of bends 14, in the embodiment shown four bends 14A — D, 15 A - D, respectively. In this embodiment, the meandering configuration is designed so as to be somewhat sinusoidal. Each body part has an outside 16 and an opposite side 17 facing the flue gas channel 11. The meandering first part can therefore have elevations 18 and lows 19. Here, as elevations 18 are seen the parts located farthest from a central plane V, and, as lows, the parts located therebetween. As central plane V, a plane V can be seen, extending approximately midway between two imaginary planes Vl and V2, with the planes Vl and V2 extending parallel to each other over the elevations 18 located farthest from the plane V of the respective body parts 3, 4. The configuration of the body parts 3, 4 and the channels 11 and/or 22 is, in fact, a zigzag configuration so that a large heat transferring surface can be obtained in a compact space.

In this embodiment, the second part 13 of each body part 3, 4 has a substantially straight form, with an outside 16 and an opposite side 17 proximal to the flue gas channel 11. In this embodiment, the plane V extends midway between these two body parts 3, 4. However, this may also be offset over a distance relative therefrom, to the left or the right in side view. On the side 17 proximal to the flue gas channel part 11, in the second part 13, on each body part 3, 4, one or a plurality of heat transferring surface increasing element(s) 20 is/are provided, fastened thereon by, for instance, gluing, welding, forcing, clamping, sintering, soldering or fastened in a different manner, which element(s) comprise(s), for instance, a pattern of projections or grooves and/or ridges, and extend(s) in the flue gas channel 11, or partly define it, so that a greater contact surface is obtained between heated flue gases in the flue gas channel 11 and the surface 17. In an alternative embodiment, the elements can be formed by a removing operation or non- removing operation of the body parts or, when for instance a casting process is used for forming the body parts, through integral forming, in particular casting, during manufacture. Also, ribs can be extruded. Alternatively or additionally, porous and/or gas transmissive materials can be used, such as metals or ceramic filling materials, In the drawing, the heat transferring surface increasing elements are represented in a simplified manner as rectangles. The design of such elements can simply be selected by skilled person and is sufficiently known per se from the state of the art, for instance from patent applications filed by the company Dejatech, the Netherlands and Dejatech Holding, Curacao. In the first part 12 and the second part 13, parts 21 of a water carrying channel 22 are provided. In the exemplary embodiment shown, these parts 21 are all tubular with a constant cross-section, which have a longitudinal direction L, approximately at right angles to the plane of the drawing in Figs. IA and 3A, which longitudinal direction L is parallel to an extrusion direction for the body parts, if these are extruded. Adjacent the first end 7, in each body part 3, 4, a first part 21A is provided as the beginning of the meandering first part 12, directly below the burner deck 6. Then, two parts 21B are provided in the second part 13. Preferably, the channel parts 21 on both sides of the flue gas carrying channel 11 are mutually connected for forming a channel 22 circumventing the heat exchanger, but, optionally, the channel parts on both sides of the flue gas carrying channel 11 can also each form a channel part 22, which can be used for, for instance, different heat exchanging circuits or be mutually connected outside the heat exchanger 1. In the channel parts 22, heat transferring surface increasing elements can be utilized too, which can be integrally formed especially through extrusion while the channel parts themselves need not be divisible.

It is preferred that the channel parts 21 are mutually connected through end hoods 24 and connecting channel parts extending therein (Fig. 8). These end hoods 24 may further comprise the connections for the heating circuits, gas and air supply pipes and the like. The end hoods can simply be fastened, with interposition of suitable gaskets, against the sides of the parts 3, 4 arranged side by side, so that a flue gas channel 11 closed towards the sides and a continuous water channel 22 or water channels 22 are obtained, while furthermore, the parts 3, 4 are held in a suitable position and at a suitable distance.

With the embodiment shown, the channel parts 21 are provided on the outside of the parts 3, 4, so that the sides thereof facing inwards, i.e. towards the flue gas channel 11, can be designed to be relatively flat, at least without protrusions formed by the channel parts. They can, however, also be positioned differently, for instance partly outside and partly inside the flue gas channel 11 or entirely inside the flue gas channel 11. This holds both for the individual channel parts and for the assembly thereof. Preferably, the or each channel 22 is laid out such that it can function in counterflow to the flow direction of the flue gases through the flue gas channel 11, so that an improved efficiency can be obtained. To that end, for instance, the through-flow opening in the different channel parts can be adjusted in order to generate a flow speed change in the channel, for a further optimisation of the heat exchange.

At the underside of the heat exchanger 1, a foot 23 is provided on which the heat exchanger can be mounted.

In Figs. 3 and 4, an alternative embodiment is given of a heat exchanger according to the invention, wherein, substantially, only those parts are described that deviate from the other embodiments. Further, reference is made to the further description, in particular of Figs. 1, 2 and 8. In this embodiment, each of the parts 3, 4 in the first part 12 has a meandering flow gas channel part HA formed between bends 14A - D, 15A- D respectively, formed such that five flue gas sub channel parts 11A¹- 11A⁵ are obtained, which are mutually connected by bend parts HB and extend approximately parallel to each other. In the first part 3, in the first bend 14A, two water channel parts 21 are included, parallel to each other, located at a distance D from each other, between a relatively wide first flue gas sub channel part HA¹ linking up with the burner deck 6 of the burner 5, and a second flue gas sub channel part 11A² located therebeneath, respectively, and between a third flue gas sub channel part HA³ and a fourth flue gas sub channel part 11A⁴ located therebeneath, respectively. These water channel parts 21 are located, for instance, adjacent the bends HB. In a comparable manner, in the second and fourth bend 15B, 15D of the second part 4, channel parts 21 are provided at a distance D from each other, between the second flue gas sub channel parti IA² and a third flue gas sub channel part HA³ located therebeneath, and between, at least under, the fourth flue gas sub channel part HA⁴ and a fifth flue gas sub channel part 11A⁵ located therebeneath, respectively. Thus, the channel parts are always in communication with at least one, and in most cases, two flue gas sub channel parts HA ^x — HA⁵, for optimal heat exchange.

With this heat exchanger, the burner deck is at an angle α relative to the plane V, for instance between 20 and 85°. In the exemplary embodiment shown, this angle is approximately 30°. With it, a desired flow pattern of the combustion gases and/or the flames can be set. However, this can also be at right angles to the longitudinal direction of the respective first flue gas sub channel part 11A¹. As is clear from the Figures, in the bends HB, further heat transfer increasing elements 2OA can be provided, for instance as ridges and intermediate passages which are disposed, for instance, in the flow direction of the flue gases or at an angle thereto, which can be provided through, for instance, a removing operation. In Figs. 5 and 6, in a schematic and perspective manner, a part 3 of a heat exchanger according to Figs. 1 and 2, and according to Figs. 3 and 4, respectively, are represented, viewed from the flue gas side 17.

In Fig. 7, the heat exchanger according to Figs. 1 and 2 is shown, as an example while, however, a second water carrying channel 26 is provided. To that end, on the parts 3, 4, between the first water carrying channel parts 21, grooves 27 and/or ribs 28 are provided for forming recesses in which a pipe 29 such, as a metal or plastic pipe is secured, for instance through clamping, form-closing, gluing, welding or in another manner. The second water carrying channel 26 can be used for, for instance, tap water. The second (or, optionally, further) water carrying channel 26 for that matter can also be integrally formed into the parts 3, 4 comparable to, for instance, the first channel 22, if the used material allows this or, for instance, when the water or other medium to be heated therein is not used for consumption but for an indirectly heated boiler, floor or wall heating or the like. Preferably, the grooves and/or ribs extend parallel to the water carrying channel parts 21, so that extrusion is possible in simple manner.

As indicated, parts 3, 4 can be advantageously formed through extrusion, separately or jointly. With it, a relatively simple and economically advantageous production of such heat exchangers is possible. However, naturally, also other manners of production can be utilized, such as casting, injection moulding and/or removing, so that somewhat more complex shapes become possible.

Preferably, the parts 3, 4 can be separated relatively easily, so that cleaning is simplified. To that end, the parts 3, 4 can be mutually screwed or clamped. This applies in particular also for the lowest, condensing part. In Fig. 8, in top plan to, schematically, a portion of a heating apparatus 25 with the heat exchanger according to the invention is shown, in a highly simplified manner, connected to two heating circuits. A first heating circuit 30 is, for instance, a space heating circuit with radiator 36, connected to the water carrying channel 22, in which a first pump 31 is provided. A second heating circuit 32 is, for instance, a tap water heating circuit with tap 37 and, optionally, a second pump 33. A supply device for, for instance, gas and air is connected to the burner chamber 5, for forming a premix burner. Naturally, only gas or another fuel can also be supplied. Adjacent the underside of the heating apparatus 25, a condensation discharge 34 may be connected to the flue gas passage 11, as well as a flue gas discharge 35.

It will be clear that combinations of parts of the embodiments shown and described here are understood to be represented too. The invention is not limited in any manner to the embodiments represented in the description and the drawings. Many variations thereon are possible within the framework of the invention as outlined by the claims. For instance, the meandering parts of the heat exchanger can have a different design and materials other than aluminum or a aluminum alloy can be utilized, for instance other (lighter) metals or ceramic materials. More or fewer water carrying channel parts may be provided, while the number of bends and the shape thereof can be adjusted to, for instance, the desired capacity. Instead of the burner with burner deck shown, a different burner can be utilized, for instance a known premix burner, which can be directly connected to the flue gas channel, in particular within the embodiment of the first flue gas sub channel part as shown in Figs. 3 and 4, which part can then, optionally, function as a part of the burner chamber. The flue gas channel can have a decreasing or, conversely, increasing passage in the direction of the flue gas discharge, in order to influence the speed of the flue gases and, hence, the heat exchange.

Claims

31ai

1. A heat exchanger, provided with a body with at least one flue gas channel and at least one water carrying channel and a burner, wherein the body comprises at least a first and a second body part, which body parts each comprise at least a first part which is of meandering design, which body parts are positioned relative to each other in a manner such that the meandering parts engage each other at least partly and therebetween a first part of the flue gas channel is formed, while each body part comprises at least a portion of the at least one water carrying channel.

2. A heat exchanger according to claim 1, wherein said first part of each body part comprises at least a first and a second bend, wherein the first bend of a first body part reaches into the first bend of the second body part and the second bend of the second body part reaches into the second bend of the first body part.

3. A heat exchanger according to claim 1 or 2, wherein adjacent a first end, means are provided for placing or forming the burner or a chamber therefor, wherein said first part of each body part comprises a series of bends, wherein in a direction away from said first end, the bends of the first body part alternately engage in and around the bends in the second body part.

4. A heat exchanger according to any one of the preceding claims, wherein in each first part of a body part and preferably in each bend therein, at least a part of said at least one water carrying channel is provided.

5. A heat exchanger according to any one of claims 2 - 4, wherein each first part in or adjacent an apex of each bend is provided with a part of the said at least one water carrying channel part, wherein on the side proximal to the flue gas channel, heat transferring surface increasing elements are provided.

6. A heat exchanger according to any one of the preceding claims, wherein each body part is provided with a second part, which second parts are located at least partly at a distance from each other and define a second part of the flue gas channel.

7. A heat exchanger according to claim 6, wherein the second parts of the body parts are provided on the sides proximal to each other with heat transferring surface increasing elements.

8. A heat exchanger according to any one of the preceding claims, wherein in a first part of each body part, at least two bends are provided which engage in or engage around a bend in an adjoining first part of the other body part, wherein the bends are formed such that they each cut a plane located midway between two parallel planes defined by the outsides of the bends in the respective first parts which are located farthest apart, measured in a direction at right angles to said parallel planes.

9. A heat exchanger according to any one of the preceding claims, wherein at least one, and preferably each body part is provided with recesses, in particular on a side remote from the flue gas channel, in which parts of a second water carrying channel are formed or included.

10. A heat exchanger according to claim 9, wherein said parts of the second water carrying channel are provided, in particular clamped, in said recesses.

11. A heat exchanger according to any one of the preceding claims, wherein the two body parts are covered on two opposite sides and are connected to end parts which seal off the flue gas channel and mutually connect parts of the at least one water carrying channel in the two body parts.

12. A heat exchanger according to any one of the preceding claims, wherein each of the body parts is substantially manufactured through extrusion.

13. A heat exchanger according to claim 12, wherein heat transferring surface increasing elements are provided on at least a part of at least one of the body parts, which elements are formed as separately provided elements and/or through a removing operation of the extruded body parts.

14. A body part for a heat exchanger according to any one of the preceding claims.

15. A body part according to claim 14, wherein the body part comprises at least a first part with a meandering configuration, wherein each body part comprises at least a portion of the at least one water carrying channel and, in addition to at least a part of said portion of the water carrying channel, is provided on a part forming a flue gas channel wall with heat transferring surface increasing elements.

16. A body part according to claim 14 or 15, substantially formed through extrusion.

17. A body part according to any one of claims 14 — 16, wherein the water carrying channel parts in each body part are provided substantially at the outside of the respective body parts.

18. A method for forming a heat exchanger, wherein at least two body parts are formed, in particular through extrusion, which body parts have at least a first part which is meandering, and each comprise at least a portion of a water carrying channel part, which body parts are mutually connected by end parts in a manner such that the body parts are thus held at a mutual distance while forming a flue gas channel, and preferably the water carrying channel parts are mutually connected in the two body parts.

19. A method according to claim 18, wherein the body parts each comprise a series of bends and, adjacent each bend, a part of the water carrying channel part is provided, which part has a longitudinal direction which is parallel to the extrusion direction.

20. A heating apparatus, provided with a heat exchanger according to any one of claims 1 — 13.