EP0414583B1 - Heat-exchanger and heater with such a heat-exchanger - Google Patents

Abstract

a) Heat exchanger, b) characterised in that it is formed: - from a stack of elements passed through by a first fluid and defining between them the passage path of a second fluid (smoke), - each element being a body forming a tube (1, 2), - by a head (3, 4) provided with means of inlet and outlet connection for the first fluid, - means of assembly, the body in the form of a tube consisting: - of a main plate (1), - of an auxiliary plate (2), the plates having deformations (16) for the exchange surfaces and distance pieces (16, 16') forming the passage path of the fluid, the head pieces comprising - a first plate end (3, 4) provided with an inlet and outlet connection (6, 7) for the first fluid, - a second end (8, 9) completing the circulation path of the first fluid, the edges (5) of two parallel sides of the elements forming distance pieces defining the circulation path of the second fluid between the elements. <IMAGE>

Description

The present invention relates to a heat exchanger and a tubular boiler provided with such a heat exchanger of the type defined in the preamble to the first claim.

Such an exchanger is already known (FR-A-2 103 583). However, this known exchanger, intended for the passage of corrosive chemical fluids, cannot be used as a heat exchanger in boilers because even if one disregards the problems of resistance to temperature and pressure, since it is made of plastic material , these plates constitute only one of the parts of the exchanger (the exchanger block) further comprising a casing which surrounds the plates and performs the functions of sealing, circulation of fluids and connection of inlet and outlet fluids.

This exchanger is relatively complicated and does not allow modular construction since the casing defines the limits of the exchanger.

The present invention aims to create a heat exchanger adaptable to boilers of very different power and which can, even after installation, be modified for example to be adapted at a higher power.

To this end, the invention relates to a heat exchanger of the type defined above, characterized by the features of the first claim.

As the heat exchanger elements are all identical and serve for the passage of a first fluid, their stacking serving for the passage of the second fluid, it is possible by the choice of an appropriate number of heat exchanger elements to produce a heat exchanger heat of any power suitable for any boiler power.

Even in an installation already carried out, it is possible if the power of the boiler must be increased, also to increase the dimensions of the heat exchanger according to this new power.

The manufacture of the heat exchanger according to the invention is extremely simple since the exchanger consists of elements simply stacked and closed on their side and, on the other hand, the elements themselves are of an extremely simple manufacture since they consist of a reduced number of parts produced by die-casting or by casting and which are joined by welds.

According to another characteristic of the invention, the main plate has returns along two parallel edges to form spacers, these edges being folded down and the auxiliary plate has returns to be welded into the main plate set back from the returns from parallel edges.

This embodiment of the heat exchanger element surrounds, thanks to the return of the main plate, the path followed by the second fluid (smoke).

According to another characteristic of the invention, the main and auxiliary plates are stamped.

According to another characteristic of the invention, the deformations of the plates correspond to a corrugated section, complementary to the main plate and the auxiliary plate, and the spacers are fixed to the plates in the recesses opposite, separating the corrugations.

It is also advantageous to produce a boiler in which a heat exchanger element according to the invention is integrated. This element can constitute the bottom surface of the boiler or the top of it.

Such a boiler, thanks to its structure formed of panels, is also of an extremely simple embodiment, by welded assembly.

• la figure 1 est une vue en plan d'un demi-élément d'échangeur de chaleur selon l'invention.
• la figure 2 est une vue de côté partiellement coupée du demi-élément de la figure 1.
• la figure 3 est une coupe transversale schématique d'un élément d'échangeur selon l'invention.
• la figure 4 montre schématiquement la superposition de deux éléments définissant le chemin de circulation du second fluide.
• la figure 5 est une vue en plan partielle du collecteur d'extrémité d'un élément d'échangeur.
• la figure 6 est une vue de côté correspondant à la figure 5.
• la figure 7 est une vue de dessus d'une variante de réalisation d'un collecteur d'un élément échangeur.
• la figure 8 est une vue éclatée très schématique d'un premier mode de réalisation d'un élément échangeur.
• la figure 9 est une vue éclatée d'un second mode de réalisation d'un élément échangeur.
• la figure 10 montre une variante de réalisation du collecteur d'un élément échangeur.
• la figure 11 est une vue éclatée d'une chaudière dont le fond est destiné à recevoir un élément échangeur selon l'invention.

The present invention will be described in more detail with the aid of the embodiments shown schematically in the accompanying drawings in which:

• Figure 1 is a plan view of a half heat exchanger element according to the invention.
• Figure 2 is a side view partially cut from the half-element of figure 1.
• Figure 3 is a schematic cross section of an exchanger element according to the invention.
• Figure 4 schematically shows the superposition of two elements defining the path of circulation of the second fluid.
• Figure 5 is a partial plan view of the end manifold of an exchanger element.
• FIG. 6 is a side view corresponding to FIG. 5.
• Figure 7 is a top view of an alternative embodiment of a collector of an exchanger element.
• Figure 8 is a very schematic exploded view of a first embodiment of an exchanger element.
• Figure 9 is an exploded view of a second embodiment of an exchanger element.
• Figure 10 shows an alternative embodiment of the collector of an exchanger element.
• Figure 11 is an exploded view of a boiler whose bottom is intended to receive an exchanger element according to the invention.

According to Figures 1, 2, 3, a heat exchanger element consists of a main plate (upper plate) 1 and an auxiliary plate (lower plate) 2 defining between them the tube or the circulation path of the heat transfer fluid (water). This path is completed at one end by an inlet / outlet manifold 3, 4 communicating with the first branch 5 of the path for circulation of the fluid.

This part 3, 4 has upper and lower flanges 6, 7, for joining together exchanger elements.

Each of the elements 3, 4 is a piece, for example of cast steel defining a chamber. At their other end, the plates 1, 2 are joined by an edge 8. The plates have at each corresponding corner an extension so as to define between the edge 8 and the left end of the exchanger a passage for the second fluid, which, for example coming from below the exchanger element shown in Figure 1, passes over it by turning at the level of the window 11. At the front, the extension 9, which may or may not receive the first fluid communicating with the path 5, as shown, has a groove 10 which is aligned with the grooves of the other exchanger elements placed above and serves to receive a seal as well as the partition closing the exchanger at this end .

At the other end, the exchanger is closed laterally by the superposition of the collectors 3, 4, and the passage of the second fluid is effected by the clearance 12 remaining between the straight edge 13 of the plates and the collector element 3, 4.

Such an arrangement makes it possible to conduct the heat transfer fluid so that it traverses the exchanger elements either in series, or in parallel, or in a mixed series-parallel combination. For this, use is made of distribution or closure cups located at the connections or between the connections of the collectors 3, 4. This arrangement also makes it possible to modify or adapt the number of stacked plates in order to adapt the power and boiler performance.

These cups are not shown in the drawings. These cups make it possible to ensure partial or total sealing of the communication between two collectors 3, 4.

FIGS. 1 and 2 also show the elongated deformations, of curved section 14, 15, of the upper plate and of the lower plate which delimit the paths for the passage of the first fluid. Some of the bosses 14, 15 are separated by a spacer 16 to which the plates 1, 2 are moreover welded.

The various elements constituting the exchanger element are joined together by welds.

The partial cross-section view shown in FIG. 3 shows the structure of an exchanger element according to the invention. This element consists of the main and auxiliary plates 1, 2, having corrugations 14, 15. This figure also reveals two spacers 16, 16 ′. These spacers are welded to the upper plate 1, directly and the connection with the lower plate 2 is made through holes 17 made in the undulations of the lower plate 2 and through which the spacers 16, 16 ′ are welded to the plate. 2.

According to FIG. 3, the main plate 1 or upper plate, according to the orientation shown, has an edge twice folded along its parts 18, 19 to form a return 19. The edge 19A of this return is welded by a weld 21 to the edge 20A of the edge 20 of the auxiliary plate or lower plate 2.

The right part of the exchanger element according to Figure 3 has a symmetrical shape to that of the left part shown explicitly. (this shape also appears in Figure 4).

According to Figure 3, the upper plate 1 has the shape of an inverted box in which one places the auxiliary plate 2. For the manufacture, once the plates 1 and 2 have been formed, the spacers 16, 16 ′ are welded to the upper plate 1, on its inner side, by the weld beads 22, 23 and then through the holes 17 are welded plugs 24 which secure the lower plate to the spacers 16. The lower plate 2 is also connected by the weld bead 21.

FIG. 4 shows the stacking of two exchanger elements 30, 31, which define between them one or more passages 32 for the second fluid. The spacing is provided by the edges of the elements thus stacked.

Figures 5 and 6 show separately and in detail the shape of a half-collector.

The heat exchanger element according to Figures 1 and 2 comprises at one of its ends two half-manifolds, one for the arrival of the first fluid, the other for the departure of the first fluid. These elements are identical to the element shown in Figures 5 and 6. One of the elements is used in the position shown in Figure 5, the other is used in the inverted position.

As already indicated, these elements consist of an inlet cylinder 40 provided with two flanges 41, 42, with bore 43 for assembling the elements together. The cylinder 40 communicates through a conduit 44 with a chamber 45 opening into a sleeve 46. The sleeve 46 is connected to the upper and lower plates of the exchanger element. The left end, according to FIG. 5, of the chamber 45 is closed by a partition 47.

The free end of the sleeve 46 is delimited by a conical peripheral surface 48 for the weld bead. It is the same for the edge 49 of the partition 47.

The surface 48 is used for the weld beads on the inlet of the chamber 5 (FIG. 1) and the conical surface 49 is used for the weld beads connecting two elements such as that of FIG. 5 to form the part coming to the end of the exchanger element as already indicated.

Figure 7 shows a variant of this end half-element. In this figure, the same references have been used to designate the same elements as above.

This element is distinguished by its main rectangular shape. It has at its inlet a chamber 55 and an outlet duct 56 also terminated by a conical peripheral surface 58 for the weld bead. This room is delimited by a partition 57 and the element continues with part 58.

The construction of an exchanger element will appear more clearly on examining FIG. 8. According to this figure, which is an exploded view, the element consists of the body 60 terminated by a head 61 forming an inlet manifold and outlet consisting very schematically of two elements placed end to end like that represented in FIG. 5. The other end of the body 60 is provided with an end element 62 which forms a circulation passage for the first fluid and comprises a opening for the passage of the second fluid.

The embodiment shown in exploded view in Figure 9 also includes a body 60 and an end 61 as in Figure 8 but the element 62 is replaced by two heels 63, 64 corresponding to the shape of the end 9 appearing at Figures 1 and 2.

Figure 11 shows a boiler according to the invention capable of receiving in its lower part an exchanger element like those described above.

This tubular hearth boiler body has a polygonal section whose facets are formed by water jackets 70, 71, 72, 73, 74, 75, 76, 77, connected together to define a path for circulation of the heat-transfer fluid. . According to the figure, 80 of the fluid (arrow) takes place in the water box 74 and the outlet takes place at the end by the end fitting 81.

The hearth body of this boiler is preferably composed of water boxes of standardized shape and the ends of the boiler are closed, as appears on the right, by a water box consisting of a first plate 82 and a second plate 83, the latter having spacers 84, 85, 86, defining the path of circulation of the heat transfer fluid. The outlet fitting 81 is connected to this water box.

Finally, the boiler has lifting or handling lugs 88, 89. On the sides there are lugs like the lugs 90, 91 which are used for screwing the not shown front end of the boiler.

According to the invention, the bottom 92 is constituted by a heat exchanger element such as those described above.

Claims (9)

1. Heat exchanger comprising:

   - a stack of elements traversed by a first fluid and defining therebetween the route of the passage of a second fluid (smoke);

   - a head (3, 4) equipped with connection means for the input and output of the first fluid;

   - assembly means;
   characterised in that each exchanger element is a body forming a tube (1, 2), the tubular body consisting of:

   - a principal plate (1);

   - an auxiliary plate (2);
   the plates having deformations (14) for the exchange surfaces and spacer members (16, 16′) forming the route for the passage of the first fluid;
   the head sections comprising:

   - a first plate end (3, 4) equipped with a connection piece (6, 7) for the input and output of the first fluid;

   - a second end (8, 9) completing the route for the circulation of the first fluid;

   - the edges (5) of two parallel sides of the elements forming spacer members defining the route for the circulation of the second fluid between the elements.
2. Exchanger according to Claim 1, characterised in that the principal plate (1) comprises turned-over sections (5) along two parallel edges in order to form the spacer members, these edges being folded over, and the auxiliary plate (2) comprises turned-over sections so as to be welded into the principal plate set back from the turned-over sections of the parallel edges.
3. Exchanger according to either of Claims 1 and 2, characterised in that the principal and auxiliary plates (1, 2) are dished.
4. Exchanger according to any one of Claims 1 to 3, characterised in that the deformations (14) in the plates (1, 2) correspond to an undulating section, which is complementary for the principal plate (1) and the auxiliary plate (2), and the spacer members (16, 16′) are secured to the plates (1, 2) in the opposite hollows, separating the undulations.
5. Exchanger according to Claim 1, characterised in that the connection pieces (6, 7) comprise flanges at the spacing between the elements for stacking the latter and connecting the elements so as to form the passage for the first fluid.
6. Exchanger according to Claim 1, characterised in that the head sections (3, 4) are cast steel parts.
7. Exchanger according to any one of Claims 1 to 6, characterised by partial or total sealing cups located between the collectors (3, 4) in order to connect the elements in series, in parallel or in parallel/series along the route of the first fluid.
8. Boiler characterised in that it is equipped with an exchanger according to any one of Claims 1 to 7.
9. Boiler having a tubular hearth with a polygonal cross-section, characterised in that it is formed of planar plates (70, 77) forming heat-transferring fluid liners, and the base (92) of the boiler is formed by an exchanger element according to any one of Claims 1 to 7.

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