BE1028744B1 - Tubular heat exchanger and method for manufacturing such tubular heat exchanger - Google Patents

Abstract

Tube heat exchanger for exchanging heat between two fluids, which tube heat exchanger (1) is provided with a housing (2) in which tubes (5) extend between a first inlet opening (3) and a first outlet opening (4) for a first fluid, wherein a inlet end plate (7b) is provided to close the first inlet opening (3) and an outlet end plate (7a) is provided) to close the first outlet opening (4), and wherein in the inlet end plate (7b) and the outlet end plate (7a) passages ( 8) are provided for the tubes (5), said tube heat exchanger (1) being provided with a second inlet opening (9) and second outlet opening (10) for a second fluid such that the second fluid in the housing (2) is intermediately and longitudinally the aforementioned tubes (5) can be guided, characterized in that the inlet end plate (7b) and outlet end plate (7a) have a circumferential shape consisting of two circle segments (11) which are connected to each other by two rec hte pieces (12) or by two pieces bent away from each other.

Description

Tube heat exchanger and method for manufacturing such a tube heat exchanger.

The present invention relates to a tubular heat exchanger.

More specifically, the invention is intended for the exchange of heat between two fluids and in particular between a gas and a liquid.

Tube heat exchangers are already known which are provided with a housing in which one or more tubes extend between a first inlet opening and a first outlet opening for a first fluid.

In order to fix these tubes in the inlet and outlet opening, two so-called end plates are provided which are arranged in the inlet and outlet opening and in which passages are provided through which the tubes extend. In this way all tubes are spaced from each other and is there room for a second fluid to be passed in between and along it.

In this context, 'longitudinal' means along an outside of the pipes.

To this end, the tube heat exchanger is provided with a second inlet section and a second outlet section for a second fluid which can be passed between and along the front tubes.

It is known that the housing of such a 3-tube heat exchanger is often not a casting made by a waistcoat process.

All the aforesaid inlet and outlet openings are hereby further processed because the dimensions of the inlet and outlet openings are not yet accurate enough just after the casting process.

However, it is important that these dimensions are very precise, as the tubes with the end plates are pushed through the housing via the first inlet and outlet opening when they are mounted. of the housing the end plates in these locations will contact the inside when the end plates are mounted with the tubes in the housing.

Especially the first inlet and outlet opening need to be finished, as the aforementioned end plates have to be mounted therein. These have a round cross-section so that a finishing processing by a turning operation with a rotating head can be done in one step,

_ BE2020/5754 3 The end plates have a round shape corresponding to this cross-section.

However, the passages through which the tubes extend are not spread over an entire surface of the endplate.

Two symmetrically opposed segments of the round shape are free of such passages and thus also 319 tubes, This to reduce the length of a path that the second fluid must traverse between the tubes to traverse all the tubes, and as such from the second inlet opening to flow to the second outlet opening, to be kept as small as possible.

If one were to pipe the entire surface of the end plates, the length of this path would be much longer and this would be accompanied by an excessive pressure drop of the second fluid. A disadvantage of the free segments of the end plates is that they pressure as the second fluid flows through the housing. As a result, the end plates bend and the tubes are stressed.

To avoid this, the end plates must be made stiffer and therefore thicker,

This effect is all the greater with large heat exchangers. Another drawback with large heat exchangers is that the dimensions of the end plates are large, and so are the 3 aforementioned segments.

This means that walls of the housing are located too far from the tubes, making it impossible to obtain an optimal conduction of the second fluid between and along these tubes.

After all, the housing must be designed in such a way that the walls bring the second fluid into contact with the tubes as closely as possible in order to obtain a good heat transfer between the second fluid and the tubes.

Due to the segments, the walls of the housing will be located relatively far from the tubes, so that the design of the walls is not optimal to obtain this effect.

The object of the present invention is to provide a solution to at least one of the aforementioned and/or other drawbacks.

The present invention features a tubular heat exchanger for exchanging heat between two fluids, the tubular heat exchanger comprising a housing in which one or more tubes extend between a first inlet opening and a first outlet opening for a first fluid, an inlet end plate being provided in the first inlet opening closing the first inlet opening and having an outlet end plate provided

N BE2020/5754 in the first outlet opening to close the first outlet opening, and wherein the inlet end plate and the outlet end plate are provided with passages through which the tubes extend, said tube heat exchanger further comprising a second inlet opening and a second outlet opening for a second fluid such that the second fluid in the housing can be passed between and along the aforesaid tubes, characterized in that the inlet end plate and the outlet end outlets have a circumferential shape consisting of two circle segments connected to each other by two straight sections or by two sections bent away from each other with a radius of curvature that is always greater than a greatest radius of curvature of the two circle segments.

A first advantage is that due to the circumferential shape of the inlet end plate and the outlet end plate, the housing can be better formed, wherein walls of the housing, in particular near the aforementioned straight sections or sections bent away from each other, can follow the tubes better and closer. , such that the second fluid can be better guided along and between the tubes. This will promote heat transfer between the first fluid and the second fluidum. Another advantage is that free segments in the endplates where no tubes would extend through them are now absent. The inlet endplate and outlet endplate will be under less pressure, so they don't have to be made thicker to prevent them from bending and stressing the tubes.

The inlet end plate and the outlet end plate are in any case smaller than in known tube heat exchangers with round end plates. This lightens the weight of the inlet end plate and the 3 outlet end plate and thus facilitates their mounting with the tubes. An additional advantage is that the first inlet and outlet opening can still be easily machined. They will have a corresponding shape to the weld end plate and outlet end plate respectively, whereby the finishing operation will consist of two turning operations: a first with a relatively small turning head for the two circle segments and a second in the form of a milling, planing or similar of the straight or curved pieces, The two circle segments must be finished at locations completely through the housing from the first inlet opening to the first outlet opening, since the housing in these locations will follow the shape of the end plates.

The straight or bent pieces, on the other hand, only need to be finished at the location of the first inlet and outlet opening.

Preferably, one or more end plates are selected from a group consisting of the inlet end plate and the

- f outlet end outlet in an axial direction of the tubes movably connected to the housing. One therefore speaks of a “floating” end plate.

This can be achieved by movably positioning at least one of these or more end plates in a ring which is secured to the housing.

The advantage of movably connecting the one or more end plates to the housing is that a thermal axial expansion of the tubes can be accommodated.

According to a preferred feature of the invention, the end plates are free of seals between the housing on the one hand and the inlet end plate and the outlet end plate respectively on the other. be small.

Although there will be a very small leakage flow of the second fluid through such clearance, it will not be necessary to provide seals. This has the advantage that no additional parts have to be provided in the tube heat exchanger, making the mounting of the tube heat exchanger easier. and cheaper.

The invention also relates to a method for manufacturing a tube heat exchanger for exchanging heat between two fluids, which method comprises the following steps:

Sa — providing a housing in which one or more tubes extend between a first inlet opening and a first outlet opening for a first fluid,

- providing an inlet end plate in the first inlet opening for closing the first inlet opening and an outlet end plate in the first outlet opening for closing the first outlet opening, and providing passages in the inlet opening and the outlet end plate through which the tubes extend, - further provided with a second inlet opening and a second outlet opening for a second fluid such that the second fluid can be passed between and longitudinally the aforesaid tubes, characterized in that the inlet end plate and the outlet end plate are made with a circumferential shape consisting of two segments of circle joined together by two straight pieces or by two pieces bent away from each other with a radius of curvature that is always greater than a greatest radius of curvature of the two circle segments,

It goes without saying that such a method results in a tube heat exchanger which offers the same advantages as the advantages of the above-described tube heat exchanger according to the invention.

In order to better demonstrate the features of the invention, some preferred embodiments of a tube heat exchanger according to the invention are described below, by way of example without any limiting character, with reference to the accompanying drawings, in which: figure 1 schematically and in perspective a tube heat exchanger according to the invention: figure 2 represents a cross-section according to the line II-IT in figure 1; Figure 3 represents a section along the line III-TLI in Figure 1; figure 1 shows a section along the line IV-IV in figure 1; figure 5 shows a detail of the cinder plates with the tubes. The tube heat exchanger 1 26 shown in figures 1 to 4 according to the invention comprises a housing 2.

The housing 2 is provided with a first inlet opening 3 and a first outlet opening 4.

A number of tubes 5 extend in the housing 2 between this first inlet opening 3 and first outlet opening 3 . A first fluid can flow through these tubes 5 . All tubes 5 together are also referred to as bundle or tube bundle.

In this case, but not necessary for the invention, the tubes 5 are provided with so-called fins 6, which will increase a heat-exchanging surface of the tubes 5 .

in the first inlet opening 3 and the first outlet opening 4, respectively, an inlet end plate 76 and an outlet end plate Yes are provided for closing the inlet and outlet opening 3, 4, respectively.

in these inlet end plate 7b and outlet end plate 7a, openings & are provided through which the tubes 5 extend. Figure 5 shows a detail of the tubes 5 with the end plates Yes, 7b. The housing 2 of the external heat exchanger 1 is also provided with a second inlet opening 9 and a second outlet opening 10. Via this second inlet opening 9 and second outlet opening 10 a second fluid can flow through the housing 2, and are passed longitudinally and loops through the aforesaid tubes 5. As can be seen in the figures, the second inlet opening 9 in a first portion 14 of the housing lies on a first lateral side of the tubes 5 and lists the second outlet opening 10 in a second portion 15 of the housing along a second lateral side of the tubes 5,

BE2020/5754 11 which second lateral side with respect to the tubes 5 is opposite the first lateral side.

In this way, the second fluid is obliged to flow 3 between the tubes 5. According to the invention, the aforesaid inlet end plate 7L and outlet plate 7a have a circumferential shape consisting of two circle segments 11 which are connected to each other by two straight pieces 12 or by two of each other. pieces bent away with a radius of curvature which is always greater than a largest radius of curvature of the two circle segments 11 . In the case of the tube heat exchanger 1 as shown in the Figures, the two circle segments 11 are semicircles.

The very inlet opening 3 and the first outlet opening 4 have a similar shape, as can be seen in Figures 11 and 4.

In this case, the housing 2 fits closely to the tubes 5, or if present the fins 6, at the circle segments 1] of the extraction shape of the inlet end plate Jb and outlet end plate 7a and a geometric extension of these circle segments 11 over the entire length. of the tubes

5.

As can be seen in figure 3 and in figure 4, inside 13 of the housing 2 has a shape complementary to two such circle segments 11 superimposed over each other over a full distance between the first inlet opening 3 and the first outlet opening 4 . a space between the tubes 5 and the housing 2 on the inside 13 is limited, so that little of the second fluid can pass around the tubes 5 along this path, so that a major part of the second fluid is forced to pass between the tubes 5 to flow. This has a favorable effect on heat transfer between the first fluid and the second fluid, both the first inlet opening 3, first outlet opening 4 and the pin side 13 of the housing 2 at the location of the geometric extension of the circle segments 11 of the circumferential shapes of the first inlet. - and outlet opening 3, 4 cover the entire length of the pipes 5 are finished, in order to eliminate irregularities of the casting of the housing 2 Le. In this case the exhaust end plate 7a is rigidly connected to the housing 2, whereby by means of bolts the outlet end plate 7a is fixed to the housing 2 .

By fixedly connected it is meant here that the outlet end plate 7a does not move relative to the housing 2 .

The inlet end plate 7b in this case is movably connected to the housing 2.

This means that the inlet end plate 7b can move relative to the housing 2 over a small distance in the axial direction of the tubes 5. This distance is sufficient to accommodate a thermal expansion ring and contraction of the tubes 5, after all if both end plates 7a, 7b would be rigidly connected to the housing 2, the distance between them would be fixed and the expansion and contraction of the tubes 5 would be accompanied by tension in the tubes 5 and the end plates 7a, 7b. To realize the movable connection of the inlet end plate 7b to the housing 2Le, one can use a ring in which the inlet end plate 765 is movably arranged in the axial direction of the tubes 5 and which ring is fixed to the housing 2 . It is not excluded according to the invention that the inlet end plate 7b is fixedly connected to the housing 2 and the outlet end plate 7a is movably connected to the housing 2, or that both the inlet end plate 760 and the outlet end plate 74 are movably connected to the housing 2.

In this case, the heat exchanger 1 is free of seals between the end plates 7a, 7b and the housing 2. Since the first inlet opening 3 and the first outlet opening 4 can be machined after inspection,

there will be only a very minimal clearance between the end holes 7b, 7a and the aforesaid openings 3, 4. Although this clearance may cause a small leakage current, whereby the second fluid can leave the housing 2, this leakage current is so small that it is negligible and does not outweigh the extra parts and additional assembly steps that would be necessary to provide the aforementioned seals, although it is not the case in this example, it is possible that in the housing 2 a number of baffle plates, baffles or so-called baffles are provided, which ensure that the second fluid has to move around the end of these baffles in order to extend a flow path of the second fluid in the housing 2 . The operation of the tube heat exchanger 1 is very simple and as follows, The first fluid will flow through the tubes 5, from the first inlet opening 3 to the first outlet opening 4 TOE.

The second fluid will flow through the housing 2, from the second inlet opening 3 to the second outlet opening 10 . The second fluid will herein make contact with the tubes D and the fins 6, as a result of which heat transfer can take place between the two fluids depending on a temperature difference between the two fluids.

It is important to note that both the first fluid can have a higher temperature than the second fluid and vice versa. Or, put another way, the heat transfer between the first and second fluid can be in both directions. id Also, both the first and second {fluid can be either gaseous or liquid.

The housing Z is designed such that the second fluid flows along and between the tubes 5, such that the heat transfer proceeds as efficiently as possible. in particular, it can be seen in the figures that the second inlet opening 3 and second outlet opening 10 are located each at one end of the tubes 5 and each on the other lateral side of the tubes 5, so that the second fluid has to flow between the tubes 5 to flow from the second inlet port 9% but the second outlet port 10,

In addition, the first portion 14 of the housing 2 on the first lateral side of the tubes 5 on one side of the second inlet opening 9 along an axial direction of the tubes 5 will taper ever closer to the tubes 5 from this second inlet opening 9, so as to such an incoming

\ BE2020/5754 16 push the flow of the second fluid in the housing 2 more and more towards the tubes 5. Conversely, the second part 15 of the housing 2 on the second lateral side of the tubes 5 on one side of the second outlet opening 10 according to an axial direction of the tubes 5 taper from this second outlet opening 10 ever closer to the tubes 5, so as to give an outgoing flow of the second fluid in the housing 2 more and more space to exit the housing 2,

Generally speaking, it can be said that the tubes 5 run diagonally through the housing 2, as it were, the second inlet opening 9 and the second outlet opening 10 defining the other diagonally,

Due to this shape of the housing 2, the heat transfer between the first fluid and the second fluid will proceed efficiently,

In this case, the second inlet port $ is located at the first outlet port 4 and the second outlet port 10 is located at the first inlet port 3,

254 As a result, the first and second fluid will flow in essentially opposite directions through the housing 2. With such an opposite flow, a logarithmic average temperature difference between the first and second fluid is maximized, which maximizes heat transfer between the first and second fluid.

After the passage of both fluids through the tube heat exchanger 1, the one fluid is heated up and the other fluid is cooled off due to the heat transfer between the two fluids.

Although in the example shown the fluids flow in essentially opposite directions through the tube heat exchanger 1, it cannot be ruled out that they flow in essentially the same direction.

The present invention is by no means limited to the embodiments described by way of example and shown in the figures, but a tube heat exchanger according to the invention can be realized in all kinds of shapes and dimensions without departing from the scope of the invention, as defined in the claims,

Claims (1)

conclusions, 1.- Bulk heat exchanger for exchanging heat between two fluids, which tube heat exchanger {1} is provided with a housing {2} in which one or more tubes {5) extend between a first inlet opening (3) and a first outlet opening {4} for a first fluid, wherein an inlet end plate (7b) is provided in the first inlet opening {3} for sealing the most inlet opening {3} and an outlet end plate {7a) is provided in the first outlet opening (4) for closing the first outlet opening (4}, and wherein the inlet end plate (70) and the outlet end plate (7a) are provided with passages (8} through which the tubes {5} extend, said tube heat exchanger (1} further comprising a second inlet opening {33 and a second outlet opening (10) for a second fluid such that the second fluid in the housing (2) can be passed between and along the aforesaid tubes (5), characterized in that the inlet end plate (7656) and the onion the late end plate (7a) have a circumferential shape consisting of two circle segments {11} which are connected to each other by two straight pieces (12) or by two pieces bent away from each other with a radius of curvature always greater than the largest radius of curvature of the two circle segments ( 11). Tube heat exchanger according to claim 1, characterized in that one or more end plates selected from a group consisting of the inlet end plate (7b3 and the outlet end plate {7a} are movably connected in an axial direction of the tubes (5) to the housing (2) . Tube heat exchanger according to claim 2, characterized in that at least one of the one or more end plates is movably arranged in a ring, which ring is fixed to the housing (2). è. Tubular heat exchanger according to one of the preceding claims, characterized in that the heat exchanger (1) is free of seals between the housing (2) on the one hand and the inlet end plate (7b} and the outlet end plate (7a) respectively on the other hand. Tube heat exchanger according to one of the preceding claims, characterized in that the tubes {5} are provided with fins {6}. Tubular heat exchanger according to claim 5, characterized in that at the area of the circle segments {11} of the circumferential shape of the inlet end plate ijb) and the outlet end plate (7a)}, and at the area of a geometric extension of these circle segments (11) over a entire length of the tubes (5), the housing (2) closely fitting to the fins (6). 7.7 Tubular heat exchanger according to one of the preceding claims 1 to 4, characterized in that at 39 the circle segments (113 of the circumferential shape of the inlet end plate (7b} and the outlet end plate (78a), and at the location of one geometry are extended from these circle segments {11} over an entire length of the tubes (5), the housing {2} closely fitting to the tubes {5}. Tube heat exchanger according to one of the preceding claims, characterized in that the second inlet opening (9) in a first portion (14) of the housing (2) is located on a first lateral side of the tubes (53, and in that the second outlet opening {10} lies in a second portion (15) of the housing (2) along a second lateral side of the tubes (5), which second lateral side with respect to the tubes (5) is opposite the first lateral side. Tubular heat exchanger according to claim 8, characterized in that the first part (14) of the casing (2} tapers increasingly closer to the pipes (5) according to an axial direction of the pipes (5) from the second inlet opening (9) in such a manner that an incoming flow of the second fluid in the housing (2) is increasingly pushed towards the tubes (5). Tubular heat exchanger according to claim 3 or 5, characterized in that the second part (15) of the housing (2} according to an axial direction of the pipes (5) from the second outlet opening (10) gets closer and closer to the pipes (5). ) tapers, such that an outgoing flow of the second fluid in the housing (2) is given more and more space to leave the housing {2}, Îl.- Tube heat exchanger according to one of the foregoing conciusions, since it is characterized that the second inlet opening {3} is located at a first end of the tubes (5) and the second outlet opening (10) is located at a second end of the tubes (5), the second end being opposite the first end, Tube heat exchanger according to claim 11, characterized in that the second inlet opening (9) is located at the first outlet opening {43, and the second outlet opening (10) is located next to the first inlet opening (3). Tube heat exchanger according to one of the preceding claims, characterized in that the two circle segments (11) are semicircles. 14. An end plate for use as an inlet end plate (70) or outlet end plate {7a} in a tube heat exchanger (1) according to any one of the preceding claims. 15. - Method for manufacturing a bulb heat exchanger (1) for exchanging heat between two fluids, which method comprises the following steps: - providing a housing (2) in which one or more tubes (5) extend between a first inlet opening (3) and a first outlet opening {4} for a first Éluidum, - providing an inlet end plate (7b} in the first inlet opening (33 for closing the first inlet opening (3) and an outlet end plate (7a) in the first exhaust opening {4} to close the first An BE2020/5754 outlet opening (4), and providing passageways (8) in the inlet end plate (76) and the outlet end plate (7a) through which the tubes (53 extend, - further providing a second inlet opening {3} and 3 a second outlet opening (10) for a second fluid such that the second fluid in the housing can be passed between and along the front tubes (5), characterized in that the inlet end plate {7b} and the outlet end plate {7a} are made with a circumferential shape consisting of two circle segments {11} which are connected to each other by two straight pieces (17) or by two pieces bent away from each other with a radius of curvature that is always greater than a greatest radius of curvature of the two circle segments (11). Method according to claim 15, characterized in that one or more of the end plates selected from a group consisting of the inlet end plate {71} and outlet end plate (7a) are movably connected in an axial direction of the tubes {5} to the housing { 2}. Method according to claim 15 or 16, characterized in that the D-tube heat exchanger (1} is manufactured without seals between the housing {2} on the one hand and the inlet end plate (76) and the outlet end plate (7a) on the other hand. Method according to one of the preceding claims 14 to 17, characterized in that the housing iz) is manufactured by means of a molding process, and in that the first inlet opening (3}, the first outlet opening (4) and an inner side {13} of the housing (2) at the location of a geometric extension of the circle segments {11} can be finished in order to eliminate irregularities as a result of the casting process. 19. Method according to claim 18, characterized in that the first inlet opening (3) and the first outlet opening (4) have a shape corresponding to the circumferential shape, and in that the first inlet opening (3) and the first outlet opening (4) are finished by two turning operations comprising: - a first turning operation with a relatively small turning xop for the circle segments {li}; and - a second turning operation in the form of a milling, planing or the like for the straight pieces (12) or the two pieces bent away from each other with a radius of curvature which is always greater than a largest radius of curvature of the two circle segments {11}.