Improved vibration device for a cryogenic heat exchanger, and associated vibration method

Abstract

TITLE: Improved Vibration Device for a Cryogenic Heat Exchanger, and Associated Vibration Method. The invention relates, among other things, to a vibration device (100) for a cryogenic heat exchanger (30) having a main body (301), the vibration device (100) comprising: - a means for generating vibration waves (102), - a vibration belt (101) configured to at least partially surround the main body (301) of the heat exchanger (30), the vibration belt (101) supporting the means for generating vibration waves (102), the means for generating vibration waves (102) being configured to transmit vibration waves to said main body (301) via said vibration belt (101). Figure for the abstract: Figure 3

Description

Title of the invention: Improved vibration device for a cryogenic heat exchanger, and associated vibration method

[0001] The invention relates to the technical field of heat exchangers, more particularly to heat exchangers for hydrogen liquefaction. More specifically, the invention relates to vibration devices for a catalyst in a cryogenic heat exchanger, where the catalyst is intended to initiate a physicochemical reaction. It also relates to a method for vibrating a cryogenic heat exchanger using such a vibration device.

[0002] Brazed plate and wave heat exchangers are classically used in the cryogenic industry for the separation and liquefaction of gases, particularly in the energy and petrochemical sectors.

[0003] These heat exchangers are formed from a set of parallel metal plates between which are generally inserted intercalated elements, such as corrugated structures or waves, which form finned heat exchange structures. The stacked plates form a stack of flat passages for different fluids to be connected for heat exchange.

[0004] Thus, a heat exchanger has internal metallic passages forming cavities through which a fluid circulates in each passage. Depending on the requirements, a cryogenic heat exchanger can be designed for the liquefaction of a gas using several dedicated fluids.

[0005] During the manufacture of the exchanger, the plates, the finned interlayer elements and the other constituent elements of the exchanger are pressed together and then joined together by brazing in a vacuum furnace.

[0006] Today, brazed plate and wave heat exchangers are being adapted to new liquefaction processes. This is the case with regard to hydrogen liquefaction processes.

[0007] Hydrogen, for example, is more stable at low temperatures when it is in the parahydrogen state, unlike in the orthohydrogen state. At low temperatures, particularly the liquefaction temperature, orthohydrogen tends to spontaneously transform into parahydrogen, releasing unwanted heat.

[0008] In order to keep hydrogen in a liquid state, two options exist.

[0009] A first option consists of continuously extracting the heat released by the conversion of orthohydrogen to parahydrogen. In practice, this technique proves to be particularly energy-intensive and not industrially profitable.

[0010] A second option is to convert orthohydrogen into parahydrogen. An exothermic catalytic reaction combined with cooling allows most of the orthohydrogen to be converted into parahydrogen. Spontaneous conversions of orthohydrogen to parahydrogen are then reduced.

[0011] This second option is one of the frameworks in which the present invention can be included without being limited to it.

[0012] To this end, a catalyst, for example in the form of catalytic powder, is inserted into the brazed plate and wave heat exchanger from an upper portion configured to receive the catalyst. During this insertion, the catalyst flows by spillage from catalyst storage means to the upper portion of the heat exchanger having a feed inlet, and then to the lower portion of the heat exchanger having a collection outlet.

[0013] A good distribution of the catalyst within the heat exchanger naturally promotes the efficiency rate of the heat exchanger.

[0014] However, ensuring good distribution of the catalyst within the heat exchanger along its height, particularly between its upper and lower parts, is not currently possible because the filling process is approximate. As a result, the catalyst is not distributed homogeneously between the upper and lower parts.

[0015] The invention therefore aims to resolve the aforementioned drawbacks.

[0016] To this end, the invention relates to a vibration device for a cryogenic heat exchanger having a main body, the vibration device comprising:

[0017] - a means of generating vibratory waves,

[0018] - a vibration belt configured to at least partially surround the body main heat exchanger,

[0019] the vibration belt supporting the means for generating vibration waves,

[0020] the means for generating vibration waves is configured to transmit vibration waves to said main body through said vibration belt.

[0021] The vibration device according to the invention provides a simple and cost-effective solution for vibrating a heat exchanger. By at least partially surrounding the main body of the heat exchanger with the vibration belt, it is possible to increase the surface area of ​​the main body of the exchanger that receives the vibrations from the means for generating vibratory waves via said belt.

[0022] The vibration of the main body of the heat exchanger promotes the flow of the catalyst from an upper part of the exchanger through which the catalyst is inserted to a lower part of the exchanger.

[0023] Thus, the invention makes it possible to distribute the catalyst more homogeneously and extensively inside the heat exchanger between its upper and lower parts.

[0024] According to one embodiment, said vibration belt comprises:

[0025] - a first support configured to be applied against a first wall of the body main,

[0026] - a second support configured to be applied against a second wall of the main body opposite the first wall of the main body,

[0027] elements configured to connect the first support and the second support and intended to apply a clamping force between the first support and the second support.

[0028] The first support and the second support with the elements ensure a tight hold of the vibration belt against the main body of the heat exchanger, so that the vibration waves of the generating means can be transmitted largely to the main body of the heat exchanger.

[0029] In the assembled state, the first support and the second support with the elements form a rigid non-deformable assembly.

[0030] According to one embodiment, the means for generating vibratory waves is connected to said first support.

[0031] This ensures the transmission of vibratory waves from the generating means to the main body via the first support.

[0032] According to one embodiment, at least one of the supports is configured to extend along a width of the wall against which it is applied, preferably each support is configured to extend along a width of the wall against which it is applied.

[0033] Such a support configuration, extending across the width of the wall of the main body against which it is applied, makes it possible to increase the surface area for the transmission of vibrational waves by the support dedicated to said main body.

[0034] According to one embodiment, the vibration device includes a vibration frequency control unit for the vibration belt in order to vibrate the main body of the cryogenic heat exchanger at a frequency equal to its resonant frequency, the control unit being connected to said means for generating vibration waves.

[0035] According to one embodiment, the vibration device comprises said means for generating vibration waves, said first means, and a second means for generating vibration waves connected to said second support and configured to transmit vibration waves to said main body through said second support.

[0036] The use of at least two means for generating vibrational waves advantageously increases the distribution of vibrational waves in the main body. The particular configuration of said generation means, mounted opposite each other, also facilitates the vibrational resonance of the main body of the heat exchanger.

[0037] According to one embodiment, the vibration device includes a surface compensation means configured to be disposed between the vibration belt and the main body of the cryogenic heat exchanger.

[0038] The use of a compensation means makes it possible to compensate for the gaps between the vibration belt and the main body, so that contact is ensured between all the supports of the vibration belt and the main body.

[0039] According to one embodiment, the means for generating vibratory waves is / are of the type unbalanced motor(s) or of the type pneumatic vibrator(s), or even of the type electromagnetic vibrator(s).

[0040] Such generation means can be configured for the generation of vibrational waves up to at least the resonance frequency of the main body of the heat exchanger.

[0041] The invention also relates to a method for vibrating a cryogenic heat exchanger using a vibration device according to the invention,

[0042] the method comprising the following steps:

[0043] a) fixing the vibration device to the main body of the cryogenic heat exchanger,

[0044] b) introduction of catalyst into the cryogenic heat exchanger,

[0045] c) setting the main body into vibration using the vibration device.

[0046] According to one embodiment, step c) is carried out prior to or simultaneously with step b).

[0047] Step c) can also be implemented after step b).

[0048] According to one embodiment, the process comprises the following steps carried out in order:

[0049] d) stopping the vibration of the main body,

[0050] e) displacement of the vibration device along a longitudinal axis of the main body,

[0051] f) execution of steps a) to c).

[0052] Other features and advantages of the invention will become apparent during the reading of the detailed description which follows, for the understanding of which reference should be made to the attached drawings.

[0053] Fig. 1 represents a perspective view of a distribution head of a cryogenic heat exchanger.

[0054] Fig. 2 represents a cross-sectional perspective view of the upper part of the distribution head of Fig. 1 illustrating a catalyst distribution.

[0055] Fig. 3 represents a cross-sectional view along plane P of Fig. 2 to illustrate an example of passage stacking.

[0056] Fig. 4 represents a perspective view of a vibration device according to the invention taken in isolation.

[0057] Fig. 5 represents a perspective view of the vibration device of claim 1 mounted on a cryogenic heat exchanger.

[0058] A brazed plate heat exchanger 30 is formed from a set of parallel plates between which corrugated structures or waves can be inserted, forming finned heat exchange structures. As shown in [Fig. 3], such stacked exchange structures 31 form a stack of flat passages for different fluids to be connected for heat exchange.

[0059] The stacked exchange structures 31 extend along the main body 301 of the heat exchanger 30 between an upper part 30A of the heat exchanger 30 and a lower part 30B of the heat exchanger 30, as shown in [Fig.5].

[0060] To ensure the liquefaction of a gas, such as hydrogen, a cryogenic heat exchanger 30 generally includes a distribution head 32, arranged opposite a collection head (not shown). The distribution head 32 distributes the fluid entering the heat exchanger 30, and the collection head collects the fluid exiting the heat exchanger 30.

[0061] Figures 1 and 2 represent a distribution head 32 of a cryogenic heat exchanger 30. Such a distribution head 32 may have one or more supply inlets 301 for supplying the distribution head 32 of the heat exchanger 30 with a fluid, generally gaseous, intended to be liquefied following its circulation through a series of passages constituting the heat exchanger 30.

[0062] The supply inlets 301 of a distribution head 32 are designed to open at the level of the stack of exchange structures 31 formed by cavities through which the gas to be liquefied flows. The characteristic size of these cavities is on the order of a millimeter and they have high length-to-width ratios.

[0063] In the context of an application to the liquefaction of hydrogen, the use of a catalyst 200 makes it possible to convert most of the hydrogen in orthohydrogen form into parahydrogen.

[0064] For this, we seek to fill the passages traversed by hydrogen with a catalyst 200 in the form of catalysis powder.

[0065] The catalyst 200 can be introduced from the supply inlet(s) 301 to reach the cavities 31A of the exchange structures 31 into which these supply inlets 301 open.

[0066] Fig. 3 represents an example of a stack of exchange structures 31 accessible from the distribution head 32 through the supply inlets 301, and forming a distribution plane P of the catalyst 200.

[0067] Today, it is difficult to obtain a homogeneous and extensive distribution of the catalyst 200 in the distribution plane P. Indeed, the catalyst 200 entering the heat exchanger 30 from its feed inlet 301 flows by gravity into a zone Z0 of the distribution plane P accessible from this feed inlet 301, so that only this zone Z0 of the distribution plane P opposite this feed inlet 301 is covered with catalyst 200. At best this zone Z0 of the distribution plane P covered with catalyst 200 can be extended by providing, for example, an increase in the feed rate of the catalyst 200 supplied from the feed inlet 301.

[0068] However, such a distribution of the catalyst 200 in the distribution plane P is not sufficiently homogeneous, nor even extensive, so that the best performance of the heat exchanger is not achieved.

[0069] The invention falls within this context and proposes a vibration device 100 for a cryogenic heat exchanger 30 having a main body 301, the vibration device 100 comprising a means for generating vibration waves 102 and a vibration belt 101 configured to partially surround the main body 301 of the heat exchanger 30,

[0070] The vibration belt 101 is advantageously designed to support the means for generating vibration waves 102.

[0071] The vibration wave generation means 102 is configured to transmit vibration waves to said main body 301 via said vibration belt 101.

[0072] Each first support 101A and second support 101B is formed by a plate having a longitudinal wall 103 having a flat surface 103' intended to be applied against the main body 301.

[0073] Each longitudinal wall 103 is configured to extend along a width of a wall 310, 320 of the main body 301 against which it is applied.

[0074] Opposite the flat surface 103', each longitudinal wall 103 has stiffening reinforcements 103A intended to strengthen its structure.

[0075] The first support 101A is configured to be applied against a first wall 310 of the main body 301, and the second support 101B is configured to be applied against a second wall 320 of the main body 301.

[0076] Optionally, a surface compensation means 104 may be provided configured to be disposed between at least one support and the main body 301 of the heat exchanger 30. The surface compensation means 104 may also be provided to be fixed to the flat surface 103' of the support, by gluing for example, so that the fixing of the support 101A, 101B pre-equipped with such a compensation means 104 is improved.

[0077] The surface compensation means 104 is provided to compensate for the gaps that may exist between the flat surface 103' of the longitudinal wall 103 of the support and the wall 310, 320 of the heat exchanger 30 against which this support 101 A, 101B is applied.

[0078] The use of a surface compensation means 104 makes it possible to improve the transmission of vibration waves by increasing the contact area of ​​the flat surface 103' of the longitudinal wall 103 of the support with the main body 301 of the heat exchanger 30.

[0079] It may be provided that the surface compensation means 104 is made of a deformable material such as a plywood plate.

[0080] Said first wall 310 of the main body 301 and said second wall 320 of the main body 301 are opposite each other.

[0081] Supporting elements 101C of the supports to each other are configured to connect the first support 101A and the second support 101B.

[0082] Furthermore, these retaining elements 101C, here longitudinal rods, are intended to apply a clamping force between the first support 101A and the second support 101B, so as to press the supports 101A, 101B against the main body 301.

[0083] To ensure this clamping force, it may be provided that the ends of the longitudinal rods 101C are threaded to receive each one a clamping bolt.

[0084] The first support 101A and the second support 101B with the retaining elements 101C ensure a tight hold of the vibration belt 101 against the main body 301 of the heat exchanger 30, so that the vibration waves of the generating means 102 can be transmitted largely to the main body 301 of the heat exchanger 30.

[0085] The first support 101A, the second support 101B and the retaining elements 101C of the supports to each other form a rigid non-deformable structure, so that the transmission of vibration waves to one of the supports 101A, 101B is transmitted to the other support 101A, 101B.

[0086] The first support 101A, the second support 101B and the retaining elements 101C of the supports 101A, 101B are advantageously adapted to the dimensions of the heat exchanger 30, so as to also retain the retaining elements 101C against the main body 301. This ensures the formation of a vibration belt 101 that is stationary relative to the main body 301 of the heat exchanger 30.

[0087] The longitudinal wall 103 of each support 101A, 101B may include fastening means 103” provided for attaching a generation means 102. In the illustrated example, the fastening means 103” are formed by threaded holes in the longitudinal wall 103 of the associated support 101A, 101B, into which retaining bolts (not shown) of the generation means 102 can be received. These fastening means 103” ensure that the vibration wave generation means 102 is held securely against the dedicated support 101A, 101B.

[0088] A control unit 600 of the vibration frequency of the vibration belt 101 can be provided.

[0089] The control unit 600 is preferably configured to cause the main body 301 of the cryogenic heat exchanger 30 to vibrate at a frequency equal to its resonant frequency.

[0090] The control unit 600 is connected to the vibratory wave generation means 102, so as to be able to control its vibration frequency.

[0091] At least one vibration wave frequency sensor 601 can be applied against the main body 301 of the heat exchanger 30 in order to measure its vibration frequency.

[0092] The control unit 600 can be configured to adapt the vibration frequency of the vibration wave generation means 102 according to the vibration frequency measured by the frequency sensor 601.

[0093] We will now describe the assembly and use of the vibration device 100 within the framework of the invention.

[0094] First, the main body 301 of the heat exchanger 30 is oriented so as to place its supply inlet(s) 301 in a high position to allow the catalyst 200 to flow by gravity from the supply inlet(s) 301 and enter the distribution head 32.

[0095] In this position, the first support 101A and the second support 101B are brought to be placed opposite each other, each against a wall 310, 320 of the main body 301 of the heat exchanger. The walls 310, 320 of the main body 301 of the heat exchanger 30 against which the supports 101A, 101B are placed are opposite each other. One or more lifting devices may be used for this purpose.

[0096] Once the two supports 101A, 101B have been positioned against the main body 301 of the heat exchanger 30, they can be fixed to each other using the retaining elements 10IC.

[0097] Each support 101A, 101B is then supported by its flat surface 103' against the wall 310, 320 of the main body 301 of the heat exchanger 30 against which it is applied. Of course, a surface compensation means 104 can be provided.

[0098] As indicated, the clamping force of the supports 101A, 101B against the main body 301 of the heat exchanger 30 can be adjusted using bolt tightening at the threaded ends of the longitudinal rods 101C.

[0099] The clamping force is sufficient to immobilize the supports 101 A, 101B against the main body 301 of the heat exchanger 30 and limit its movement relative to the main body 301 during a subsequent vibration step.

[0100] The means for generating vibrational waves 102 can be pre-mounted to the first support 101A intended to receive it, or alternatively it can be fixed to its support 101A, 101B once the supports 101A, 101B are held against the main body 301.

[0101] Once the vibration device 100 is mounted on the main body 301 of the heat exchanger 30, the lifting device(s) can be removed.

[0102] Regardless of the attachment of the vibration device 100, the supply inlet(s) 301 is connected to a catalyst distribution device 200.

[0103] The method for vibrating the main body 301 of the heat exchanger 30 consists of vibrating said main body 301 in order to optimize the flow of the catalyst 200 along the main body 301 of the exchanger 30 from its upper part, which includes the distribution inlet(s) 301 through which the catalyst 200 enters, towards its lower part. Vibrating the main body 301 promotes the diffusion of the catalyst 200 along it from the distribution plane P of the distribution head 32.

[0104] Vibrating the main body 301 of the heat exchanger 30 at its resonant frequency improves the propagation of the diffusion of the catalyst 200 in the main body 301 of the exchanger 31.

[0105] The distribution of catalyst 200 via the supply inlet(s) 301 can advantageously be carried out once the vibration of the main body 301 of the heat exchanger has been activated. Of course, it is also possible to supply the heat exchanger 31 with catalyst 200 before or simultaneously with its vibration.

[0106] The position of the vibration device 100 relative to the main body 301 can advantageously be adjusted along the latter, so that it is possible to set into vibration a desired part of said main body 301.

[0107] Although the present description refers to specific embodiments, modifications may be made to these examples without departing from the general scope of the invention as defined by the claims. Furthermore, individual features of the various embodiments illustrated or mentioned may be combined in additional embodiments. By Therefore, the description and drawings should be considered in an illustrative rather than restrictive sense.

Claims

Demands

1. Vibration device (100) for a cryogenic heat exchanger (30) having a main body (301), the vibration device (100) comprising: - a means for generating vibration waves (102), - a vibration belt (101) configured to surround at least part of the main body (301) of the heat exchanger (30), the vibration belt (101) supporting the means for generating vibration waves (102), the means for generating vibration waves (102) being configured to transmit vibration waves to said main body (301) via said vibration belt (101).

2. Vibration device (100) according to the preceding claim, wherein said vibration belt (101) comprises: - a first support (101A) configured to be applied against a first wall (210) of the main body (301), - a second support (101B) configured to be applied against a second wall (220) of the main body (301) opposite the first wall (210) of the main body (301), elements (101C) configured to connect the first support (101A) and the second support (101B) and provided for applying a clamping force between the first support (101A) and the second support (101B).

3. Vibration device (100) according to the preceding claim, wherein the means for generating vibration waves (102) is connected to said first support (101A).

4. Vibration device (100) according to any one of claims 2 or 3, wherein it comprises said vibration wave generation means (102), said first generation means, and a second vibration wave generation means (103) connected to said second support (101B) and configured to transmit vibration waves to said main body (301) via said second support (101B).

5. Vibration device (100) according to any one of claims 2 to 4, wherein at least one of the supports (101A, 101B) is configured to extend along a width of the wall (210, 220) against which it is applied, preferably each support (101A, 101B) is configured to extend along a width of the wall (210, 220) against which it is applied.

6. Vibration device (100) according to any one of claims 1 to 3, wherein the vibration device (100) comprises a vibration frequency control unit (600) of the vibration belt (101) for the purpose of vibrating the main body (301) of the cryogenic heat exchanger (30) at a frequency equal to its resonant frequency, the control unit (600) being connected to said vibration wave generation means (102).

7. Vibration device (100) according to any one of the preceding claims, wherein the vibration device (100) comprises a surface compensation means configured to be disposed between the vibration belt (101) and the main body (301) of the cryogenic heat exchanger (30).

8. Vibration device (100) according to any one of the preceding claims, wherein the vibration means is / are of the unbalanced motor(s) type or of the pneumatic vibrator(s) type, or of the electromagnetic vibrator(s) type.

9. Method of vibrating a cryogenic heat exchanger (30) using a vibration device (100) according to any one of claims 1 to 8, the method comprising the following steps: a) attaching the vibration device (100) to the main body (301) of the cryogenic heat exchanger (30), b) introducing catalyst (200) into the cryogenic heat exchanger (30), c) vibrating the main body (301) using the vibration device (100).

10. A method according to the preceding claim, wherein the method comprises the following steps carried out in order: d) stopping the vibration of the main body (301), e) moving the vibration device (100) along a longitudinal axis (A) of the main body (301), f) carrying out steps a) to c).

Images