Heat exchanger including spacers

Abstract

A heat exchanger (1) comprising: - a body (3) provided with a number of compartments (4) including two end compartments (7), each compartment (4) defining an internal volume through which a fluid can flow and each compartment (4) comprising at least one opening (5) through which a fluid passes to enter or leave said internal volume; - a separation wall (6) arranged between two adjacent compartments (4) separating the internal volumes from one another; - a closure wall (9) arranged in each of the two end compartments (7) intended to close an internal end volume of said end compartment (7); wherein the heat exchanger (1) comprises a number of spacers (12) arranged inside the compartments (4) and along the openings (5), said spacers (12) being capable of maintaining a distance (d) between two adjacent separation walls (6) and / or said spacers (12) being capable of maintaining a distance (d) between the closure wall (9) and the separation wall (6) adjacent to said closure wall (9).

Description

[Technical field]

[0001] The present invention is in the technical field of heat exchangers, and more specifically, the present invention relates to plate heat exchangers filled with powders designed to initiate physical / chemical reactions. [Background technology]

[0002] Brazed plate heat exchangers are traditionally used in the cryogenic industry for gas separation and liquefaction, and in the energy and petrochemical sectors.

[0003] As part of the energy transition with major CO2 emission reduction targets, many countries are showing increased interest in new energy sources. In this context, brazed plate heat exchangers are being adapted for new industrial-scale processes. This is the case for the hydrogen liquefaction process, which is linked to the development of hydrogen mobility.

[0004] For example, hydrogen is more stable at low temperatures in the para-hydrogen state than in the ortho-hydrogen state. At low temperatures, especially liquefaction temperatures, ortho-hydrogen tends to spontaneously convert to para-hydrogen, releasing undesirable heat.

[0005] To keep the hydrogen in its liquid state, there are two options: the first is to continuously extract the heat released by the conversion of ortho-hydrogen to para-hydrogen, but in practice this technique has proven to be particularly energy intensive and uneconomical on an industrial scale.

[0006] The second option is to remove the orthohydrogen by converting it to parahydrogen. An exothermic catalytic reaction combined with cooling converts most of the orthohydrogen to parahydrogen. The spontaneous conversion of orthohydrogen to parahydrogen is then reduced.

[0007] This second option is one area in which the present invention can be applied.

[0008] To use catalysts, often in powder form, which are inserted into the heat exchanger after the brazing operation, it is necessary to use hydrogen distribution heads with large openings whose cross section is substantially equal to that of the heat exchanger in question, which ensures a uniform powder distribution in the exchanger section.

[0009] This means that the distribution heads are particularly large and have an impact on the heat exchanger.

[0010] Conventional heat exchangers typically include longitudinal and end bars that define compartments separated from one another by sealed separating walls.

[0011] In the case of a distribution head whose cross section is approximately equal to that of the heat exchanger, there are no end bars in the catalyst receiving compartment, since they would prevent the insertion of the catalyst in powder form, but the overall structure of the heat exchanger is weakened, since the end bars contribute to the mechanical strength of the heat exchanger and to the distribution of welding stresses.

[0012] During assembly, the distribution head is welded to the heat exchanger. Weld cooling, material expansion, and material contraction cause mechanical stresses that can distort the main structure of the heat exchanger, reducing its efficiency. A further drawback is that these deformations make it more difficult to fill the heat exchanger with powdered catalyst, resulting in an uneven distribution of catalyst that is detrimental to the performance of the unit.

[0013] The present invention aims to address these shortcomings. Summary of the Invention

[0014] For this purpose, a heat exchanger is provided, - a body provided with a plurality of compartments including two end compartments, each compartment defining an internal volume through which a fluid can flow, each compartment comprising at least one opening through which a fluid may pass to enter or exit said internal volume; a separation wall arranged between two adjacent compartments and separating the interior volumes from each other; a closing wall arranged in each of the two end sections and intended to close an internal end volume of said end section, The heat exchanger comprises a plurality of spacers arranged along the opening inside the compartment, the spacers being capable of maintaining the distance between two adjacent separation walls and / or the spacers being capable of maintaining the distance between a closing wall and a separation wall adjacent to the closing wall.

[0015] Such a heat exchanger allows the exchanger structure to absorb the mechanical stresses inherent in the cooling of the weld, which makes it easier to fill the powder.

[0016] Various additional features may be provided alone or in combination.

[0017] the heat exchanger comprises at least one head for distributing a fluid to the compartments, the spacer being arranged in the vicinity of said distribution head; the spacer is arranged substantially at one longitudinal end of the body, said longitudinal end being located at the interface between the distributor head and the body; the spacer is provided with at least one perforation allowing the passage of fluids and / or powders; the spacer comprises a first surface designed to be in contact with a separating wall and a second surface opposite the first surface designed to be in contact with another separating wall or a closing wall; - In the same compartment, spacers are placed side by side, spaced apart by a distance between 5 and 30 centimeters; - spacers are disposed in at least two compartments adjacent to one another, the spacers being substantially aligned one below the other; a spacer is disposed in each of the at least two end sections located at the lower and upper ends of the heat exchanger, a spacer being disposed in a section adjacent to each of the end sections; the spacer has a length / width ratio between 0.5 and 5, preferably between 0.8 and 2, the spacer is of parallelepiped shape, The spacer is cylindrical, The spacer is oval in shape.

[0018] In this application, the length of the spacer is defined in the direction of fluid flow within the compartment, and the width is defined perpendicular to the direction of fluid flow within the compartment. [Brief description of the drawings]

[0019] Further features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings. [Figure 1] 1 is a schematic perspective view of a portion of a heat exchanger according to the present invention; [Diagram 2] 1 is a schematic diagram of a cross section of a heat exchanger with a spacer according to the present invention; [Diagram 3] FIG. 3 is a first schematic diagram of the spacer from FIG. 2. [Figure 4] FIG. 3 is a second schematic diagram of the spacer from FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] [FIG. 1] shows a heat exchanger 1 according to the present invention. First, a longitudinal axis X is defined, which extends along the length of the heat exchanger 1, corresponding to the maximum dimension of the heat exchanger 1. Second, a first transverse axis Y is defined, which is substantially perpendicular to the longitudinal axis X and extends along the width of the heat exchanger 1. The X and Y axes form a plane XY. Finally, a third transverse axis Z is defined, which is substantially perpendicular to the X and Y axes and extends along the height of the heat exchanger 1. The Z axis forms a plane ZX together with the X axis, and a plane ZY together with the Y axis.

[0021] The heat exchanger 1 comprises several longitudinal bars 2 which together define a body 3 provided with compartments 4 which define an internal volume in which a fluid can circulate. Each compartment 4 is bounded laterally along the Y axis by a longitudinal bar 2. The compartments 4 are adjacent to one another; in other words, the compartments 4 are juxtaposed one above the other along the Z axis.

[0022] Each compartment has an opening 5 through which fluid can enter and exit the interior volume.

[0023] The heat exchanger 1 comprises a separation wall 6. Located between each compartment 4 is a separation wall 6. The separation walls 6 separate the compartments 4, and thus the corresponding internal volumes, from one another along the Z axis.

[0024] On both sides of the heat exchanger 1 along the Z axis, the heat exchanger comprises end sections 6 located at a lower end 7 and at an upper end 7. A closure wall 9 is arranged in each end section 7, thus closing the internal end volume and, in so doing, closing the heat exchanger 1.

[0025] As shown in FIG. 1, the heat exchanger 1 includes a fluid distribution head 10 located at an inlet 11 of the heat exchanger 1. The distribution head 10 has a cross section in the ZY plane substantially equal to the cross section of the body 3 of the heat exchanger 1.

[0026] Fluids thus dispensed by the dispensing head 10 are dispensed into accessible compartments 4 arranged along the Z axis.

[0027] The heat exchanger 1 further comprises a collection head (not shown) arranged opposite the dispensing head 10. The collection head collects the fluid exiting the heat exchanger 1.

[0028] The dispensing head 10 is attached to the body 3 by welding. Once the weld is complete, cooling of the weld metal creates mechanical stresses on the body 3. These mechanical stresses are commonly referred to as "material shrinkage".

[0029] Advantageously, the heat exchanger 1 comprises a number of spacers 12. As can be seen in FIG. 2, the spacers 12 are arranged inside the compartments 4. The spacers 12 are arranged along the openings 5. When the spacers 12 are arranged between two separation walls 6, the spacers 12 maintain the distance d between two adjacent separation walls 6. When the spacers 12 are arranged between a separation wall 6 and a closing wall 9, the spacers 12 maintain the distance d between the separation wall 6 and the closing wall 9.

[0030] The spacers 12 thus arranged prevent deformation of the compartments 4 as a result of material shrinkage due to welding operations to the distribution head 10 or the collection head 10. Since the openings 5 ​​are not deformed, the operation of filling the compartments 4 with catalyst powder is possible and easy. Furthermore, the spacers 12 prevent the formation of compartments 4 through which the fluid cannot easily pass, since a deformed compartment is more difficult for the fluid to access. This would create preferential passages for the fluid and destroy the uniformity of the fluid distribution in the heat exchanger 1.

[0031] Advantageously, the spacers 12 are arranged in the vicinity of the dispensing head 10 and the collecting head (not shown), where mechanical stresses are present that would tend to deform the compartment 4. The spacers 12 arranged there advantageously prevent deformation of the compartment 4.

[0032] Advantageously, the spacers 12 are arranged at the longitudinal ends 13 of the body 3 along the X-axis. The longitudinal ends 13 are located at the boundary between the distribution or collection head 10 on the one hand and the body 3 on the other hand. It is at the longitudinal ends 13 of the body that the risk of deformation is greatest. The spacers 12 arranged in this way advantageously prevent deformation of the longitudinal ends 13 of the body 3, into which the catalyst in powder form is inserted. This facilitates filling.

[0033] Advantageously, the spacer 12 is provided with perforations 14. The spacer 12 presents an obstacle to the passage of the fluid and / or catalyst powder. The perforations 14 are of a size such as to allow the passage of the fluid and / or catalyst powder. This reduces the effect of the spacer 12 on the flow of the fluid and / or the packing of the catalyst powder.

[0034] Advantageously, the spacers 12 have a length L / width 1 ratio between 0.5 and 5, preferably between 0.8 and 2. In particular, the higher the ratio, the more limited the effect of the spacer on the flow in the passage. It should also be noted that each spacer is defined by a length defined along the X axis, a width defined along the Y axis, and a height defined along the Z axis (see FIG. 4).

[0035] According to one embodiment shown in FIG. 2, the spacers 12 have a rectangular parallelepiped shape. Thus, each spacer 12 has a first face 15 in contact with the first separation wall 6 and a second face 16 in contact with the second separation wall 6 adjacent to the first separation wall 6 or with the closure wall 9. The spacers 12 thus have a height h measured along the Z axis that is substantially equal to the distance d measured along the Z axis between the two separation walls 6 or between the separation wall 6 and the closure wall 9. The spacers 12 thus sized make it possible to maintain the distance d at the end of the welding operation.

[0036] In a given section, the spacers 12 are positioned side by side and spaced apart by a distance k between 5 and 30 centimeters measured along the Y axis.

[0037] 2, the spacers 12 are arranged in the end sections 7 located below the closure wall 9. The end sections 7 are located at the lower end 8 and at the upper end 8 along the Z axis. The spacers 12 are arranged in sections 17 adjacent to the end sections 7. The applicant has determined that it is effective to arrange the spacers 12 in at least two adjacent sections to prevent the body 3 from deforming. By arranging the spacers in the end sections 7 and the adjacent sections 17, deformation is avoided since these sections concentrate the highest mechanical stresses due to their proximity to the welds.

[0038] Advantageously, the spacers 12 are arranged one below the other, i.e. aligned along the Z axis as shown in FIG. 2. By overlapping the spacers 12 in this manner, pinching of the separation wall 6, which would result in wavy separation wall 6, is avoided. Staggering the spacers 12 would result in pinching of the separation wall 6, and therefore in undesirable waviness.

[0039] In an embodiment not shown, the spacer is cylindrical. Each flat surface of the spacer contacts the closing or separating wall, and the circular surface contacts the fluid or catalyst powder. A spacer of this shape is advantageous because it facilitates the flow of the powder or fluid.

[0040] In another embodiment, not shown, the spacer is elliptical. Each flat surface of the spacer is in contact with the closure or separation wall, and the elliptical surface is in contact with the fluid or catalyst powder. This aircraft wing shaped spacer is advantageous because it facilitates the flow of the powder or fluid.

Claims

1. A heat exchanger (1), comprising: a body (3) provided with a number of compartments (4) including two end compartments (7), each compartment (4) defining an internal volume through which a fluid can flow, each compartment (4) comprising at least one opening (5) through which a fluid passes to enter or leave said internal volume; a separating wall (6) placed between two adjacent compartments (4) and separating said internal volumes from each other; - a closure wall (9) arranged in each of the at least two end sections (7) and intended to close the internal end volumes of the at least two end sections (7), the heat exchanger (1) comprising a plurality of spacers (12) arranged along the openings (5) inside the sections (4), the spacers (12) being capable of maintaining the distance (d) between two adjacent separation walls (6) and / or the spacers (12) being capable of maintaining the distance (d) between the closure wall (9) and the separation wall (6) adjacent to the closure wall (9).

2. 2. The heat exchanger (1) according to claim 1, wherein the heat exchanger (1) comprises at least one head (10) for distributing the fluid to the compartments (4), and the spacer (12) is located in the vicinity of the distribution head (10).

3. 3. The heat exchanger according to claim 2, wherein the spacer (12) is arranged substantially at one longitudinal end (13) of the body (3), the longitudinal end (13) being located at the boundary between the distribution head (10) and the body (3).

4. 2. The heat exchanger (1) according to claim 1, wherein the spacer (12) is provided with at least one perforation (14) that allows fluids and / or powders to pass through the spacer (12).

5. 2. The heat exchanger (1) according to claim 1, wherein the spacer (12) comprises a first surface (15) intended to be in contact with a separation wall (6) and a second surface (16) opposite the first surface (15) intended to be in contact with another separation wall (6) or a closure wall (9).

6. 2. The heat exchanger (1) according to claim 1, wherein in a single compartment (4), the spacers (12) are arranged side by side and spaced apart by a distance (k) of between 5 and 30 centimeters.

7. 2. The heat exchanger (1) according to claim 1, wherein the spacers (12) are arranged in at least two compartments (4) adjacent to each other, the spacers (12) being substantially aligned one below the other.

8. 8. The heat exchanger according to claim 7, wherein the spacers (12) are arranged in each of the at least two end sections (7) located at the lower and upper ends (8) of the heat exchanger (1), and the spacers (12) are arranged in sections (17) adjacent to each of the end sections (7).

9. 2. The heat exchanger (1) according to claim 1, wherein the spacer (12) is parallelepiped shaped.

10. 2. The heat exchanger (1) according to claim 1, wherein the spacer is cylindrical.

11. 2. The heat exchanger (1) according to claim 1, wherein the spacers are elliptical.

12. 2. Heat exchanger (1) according to claim 1, wherein said spacers have a length / width ratio of 0.5 to 5, preferably 0.8 to 2.

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