Heat exchanger with improved mixing device arrangement for distribution of two-phase mixture

Abstract

The present invention relates to a heat exchanger (1) comprising a plurality of plates (2) arranged parallel to each other and to a longitudinal direction (z), said plates (2) being stacked in a spaced apart manner so as to define between each other at least one first set of passages (10A, 10B) configured for a first fluid (F1) to flow generally along the longitudinal direction (z) and at least one second set of passages (20) configured for a second fluid (F2) to flow so as to form a heat exchange relationship with the first fluid (F1), at least one first passage (10A) of the first set comprising a first mixing device (3A) and at least one second passage (10B) of the first set comprising a second mixing device (3B), each of the first and second mixing devices (3A, 3B) comprising at least one lateral channel (31A, 31B) configured for a first phase (61) of the first fluid (F1) to flow from at least one first inlet (311A, 311B), a series of longitudinal channels (32A, 32B) extending along the longitudinal direction (z) and each configured for a second phase (62) of the first fluid (F1) to flow from a second inlet (321A, 321B) to a second outlet (322A, 322B), said longitudinal channels being consecutive to each other along a lateral direction (y) orthogonal to the longitudinal direction (z), and at least one opening (34) fluidically connecting said at least one lateral channel (31A, 31B) to at least one longitudinal channel (32A, 32B) so that the first and second mixing devices (3A, 3B) are configured to dispense a mixture of the first phase (61) and the second phase (62) through the second outlet (322A, 322B). According to the invention, the longitudinal channels (32A) of the first mixing device (3A) are arranged at least partially along the lateral direction (y) at different locations than the locations of the longitudinal channels (32B) of the second mixing device (3B).

Description

[0001] The present invention relates to a heat exchanger comprising a plurality of sets of passages for each of a plurality of fluids to be brought into heat exchange relationship, the heat exchanger comprising a mixing device arrangement configured to distribute more evenly at least one mixture consisting of a liquid-gas two-phase in at least one set of passages.

[0002] In particular, the present invention can be applied to a heat exchanger which vaporizes at least one stream of a liquid-gas mixture, in particular a stream of a liquid-gas mixture having a plurality of constituent elements, such as a mixture comprising hydrocarbons, by heat exchange with at least one other fluid, such as a cooled or even at least partially liquefied natural gas, or even a supercooled liquefied natural gas.

[0003] Among the methods using one or more fluid refrigeration cycles with a two-phase coolant, i.e. in a liquid / gas mixture state, several methods are known for liquefying a natural gas stream to obtain a liquefied natural gas (LNG). Typically, a cooled stream, typically a mixture having a plurality of constituent elements, such as a mixture comprising hydrocarbons, is compressed by a compressor and then introduced into an exchanger or a series of exchangers where it is completely liquefied and supercooled to the coldest temperature of the method, typically the coldest temperature of the liquefied natural gas stream. At the coldest outlet of the exchanger, the cooled stream is expanded by forming a liquid phase and a gas phase. These two phases are separated by a phase separator and then reintroduced into the exchanger and remixed before being reintroduced into the exchanger in a liquid-gas mixture state, i.e. in a two-phase state. The cooled stream introduced into the exchanger in a two-phase state vaporizes therein against the liquefied hydrocarbon stream and against the natural gas. The document WO-A-2017 / 081374 describes one of these known methods.

[0004] Brazed plates and finned aluminum exchangers are used to allow a very compact device to be provided which provides a large exchange surface, thus improving the energy performance capacity of the method, and does so in a limited volume.

[0005] These exchangers comprise a stack of plates extending in two dimensions, length and width, thus forming a stack of a plurality of sets of passages positioned one above the other, some of which are used to circulate a heat transfer fluid, for example a hydrocarbon stream to be liquefied, and others of which are used to circulate a coolant, for example a two-phase cooled stream to be vaporized.

[0006] Heat exchange structures, such as heat exchange corrugations, are generally arranged in these passages of the exchanger. These structures comprise fins extending between the plates of the exchanger and allow the heat exchange surface of the exchanger to be increased. They also act as spacers and contribute to the mechanical strength of the passages.

[0007] Some problems can arise in exchangers that implement two-phase cooling flows, especially when their vaporization occurs in the rising vertical direct current.

[0008] In fact, to ensure proper operation of the exchanger, and especially to maximize the use of the exchange surface of the exchanger (particularly for exchangers implementing liquid-gas mixtures), the ratio of the liquid phase to the gas phase must be the same in all passages and must be uniform in the same passage.

[0009] The dimensions of the exchanger are calculated under the assumption that the phases are uniformly distributed and therefore the liquid phase in each passage has a single temperature (equal to the dew point of the mixture) at the end of vaporization.

[0010] Especially for mixtures with multiple constituent elements, the endpoint of the vaporization temperature will depend on the ratio of the liquid and gas phases in the pathway, since the two phases do not have the same composition.

[0011] When the two phases are unevenly distributed, the temperature profile of the first fluid will therefore vary depending on the path and / or within the same path. Due to this uneven distribution, one or more fluids that have an exchange relationship with the two-phase mixture may have an exchanger outlet temperature higher than expected, which thus reduces the performance capability of the heat exchanger.

[0012] One solution for distributing the liquid and gas phases of a mixture as uniformly as possible involves introducing them separately into an exchanger and then mixing them together only after they are inside the exchanger.

[0013] Documents FR-A-2563620 or WO-A-2018 / 172644 describe such an exchanger in which a grooved rod is inserted into a set of passages for guiding a two-phase mixture. This mixing device includes a series of separate channels or grooves for the liquid phase flow of the coolant and another series of separate channels for the gas phase flow of the coolant. One series of channels is fluidly connected to the other series of channels via openings, such that the liquid-gas mixture is distributed from the mixing device toward the heat exchange zone. Each coolant passage of the exchanger is provided with such a device.

[0014] One problem with this type of mixing device is the uneven distribution of the liquid-gas mixture across the width of the exchanger passage.

[0015] In practice, the two-phase mixture is distributed at the outlet of the channel in the inlet passage. Because the channels are arranged at intervals, the width of the liquid-gas mixture across the passage is discretely introduced into the exchange zone. As the fluid flows in the exchanger along the overall flow direction, distribution can be achieved, particularly by means of the exchange corrugations commonly used in this type of exchanger (such as perforated corrugations or "sawtooth" corrugations that tend to deflect some fluid away from its flow direction), in a direction orthogonal to the overall flow direction.

[0016] However, homogenization of fluid distribution across the width of the exchanger can only be achieved after the mixture has traveled a certain distance away from the mixing device. Over this distance, depending on the location considered across the exchanger width, the fluid is supplied to the exchange zone at a non-uniform mass flow rate. Some channels of the exchange corrugations may have only a limited supply or even no supply at all. The performance capability of the exchanger is reduced. In some configurations, acceptable homogenization may not even be achievable. This is especially true when the exchange zone is equipped with straight corrugations, in which case distribution cannot be achieved by lateral deflection of the fluid.

[0017] Exchangers operating with low temperature deviations between the heat transfer fluid and the coolant fluid are more sensitive to this poor distribution phenomenon. Furthermore, the uneven distribution is even more pronounced when the coolant mixture contains multiple constituent elements.

[0018] None of the existing solutions are entirely satisfactory. Therefore, placing free space at the outlet of the mixing unit introduces mechanical strength issues for the exchanger and causes the first phase to accumulate in that area. Increasing the number of successive channels across the exchanger width leads to a decrease in the flow velocity in each channel and is detrimental to proper distribution of the mixture at the outlet. Finally, a "hard-channel" corrugated arrangement at the mixing unit outlet or an arrangement of mixing units with more complex geometries increases pressure loss, which reduces the performance capability of the method.

[0019] The object of the present invention is to solve all or some of the above-mentioned problems, particularly by providing a mixing device that provides a more uniform distribution of the two-phase mixture across the width of the exchanger.

[0020] The solution according to the invention also relates to a heat exchanger comprising a plurality of plates arranged parallel to each other and parallel to a longitudinal direction, the plates being stacked in a spaced-apart manner to define together at least one first set of passages and at least one second set of passages, the at least one first set of passages being configured for a first fluid to flow generally in the longitudinal direction, the at least one second set of passages being configured for a second fluid to flow to form a heat exchange relationship with the first fluid, the at least one first passage of the first set including a first mixing device, and the at least one second passage of the first set including a second mixing device, each of the first mixing device and the second mixing device comprising:

[0021] - At least one lateral channel, the at least one lateral channel being configured to allow a first phase of the first fluid to flow from at least one first inlet;

[0022] - A series of longitudinal channels extending longitudinally, each configured to allow the second phase of the first fluid to flow from a second inlet to a second outlet, the longitudinal channels being sequentially arranged in lateral directions orthogonal to the longitudinal direction; and

[0023] - At least one opening fluidly connects the at least one lateral channel to at least one longitudinal channel, such that the first mixing device and the second mixing device are configured to dispense a mixture of the first phase and the second phase via a second outlet of their respective longitudinal channels.

[0024] The feature is that the longitudinal channel of the first mixing device is arranged at least partially in the lateral direction at a position different from that of the longitudinal channel of the second mixing device.

[0025] Where applicable, the present invention may include one or more of the following features:

[0026] - The second mixing device includes two longitudinal edges extending parallel to the longitudinal direction, and each longitudinal channel of the first mixing device is inserted between two successive longitudinal channels of the second mixing device or between a longitudinal channel of the second mixing device and a longitudinal edge along the lateral direction;

[0027] - A single longitudinal channel of the first mixing device is inserted in the lateral direction between two successive longitudinal channels of the second mixing device, or between the longitudinal channel of the second mixing device and the longitudinal edge;

[0028] - The longitudinal channels of the first mixing device are separated from each other by a first constant distance, and the longitudinal channels of the second mixing device are separated from each other by a second constant distance, preferably the first distance and the second distance are equal;

[0029] - A series of longitudinal channels of the second mixing device are offset relative to a series of longitudinal channels of the first device by an offset distance measured in the lateral direction, preferably between 25% and 75% of the first distance, and preferably 50% of the first distance;

[0030] - The range of the first distance and / or the second distance is between 10 mm and 40 mm, preferably greater than or equal to 20 mm and less than or equal to 30 mm;

[0031] - Each of the first and second channels has a longitudinal axis of symmetry extending parallel to the longitudinal direction, and the longitudinal channels of each first and second mixing device are arranged symmetrically with respect to the longitudinal axis of symmetry.

[0032] -The position of the longitudinal channel of the second mixing device in the lateral direction is rotated 180° in the plane defined by the lateral and longitudinal directions, and then coincides with the position of the longitudinal channel of the first device in the lateral direction.

[0033] - The switch includes a plurality of alternating first and second paths, with at least one path in the second group arranged between at least one first path and at least one second path following the at least one first path;

[0034] - The lateral and / or longitudinal channels of the first and second mixing devices are straight, preferably parallelepiped or generally parallelepiped in shape;

[0035] - The first mixing device and the second mixing device each include a series of lateral channels that extend in the lateral direction and are sequential to each other in the longitudinal direction.

[0036] According to another aspect, the present invention relates to a method for liquefying a hydrocarbon-containing stream, such as natural gas, as a second fluid, said method implementing at least one exchanger according to the invention, and comprising the following steps:

[0037] a) Introduce the hydrocarbon stream into the pathway of the second group;

[0038] b) Introduce the cooling flow into the third set of passages of the heat exchanger;

[0039] c) Discharge the cooling flow from the heat exchanger and expand the cooling flow to at least one pressure level to generate at least one two-phase cooling flow;

[0040] d) Separate at least a portion of the two-phase cooling flow originating from step c) into a gas phase and a liquid phase;

[0041] e) At least a portion of the gas phase and at least a portion of the liquid phase are introduced into each of the first and second passages of the first group via separate inlets of the first and second passages, respectively.

[0042] f) The phases introduced in step e) are fed into the first mixing unit and the second mixing unit so that a first fluid formed by the mixture of the first phase (61) and the second phase is obtained at the outlet of each of the first mixing unit and the second mixing unit;

[0043] g) By exchanging heat with at least the hydrocarbon stream, at least a portion of the first fluid originating from step f) is vaporized in the first and second passages to obtain a cooled and / or at least partially liquefied hydrocarbon stream at the outlet of the exchanger.

[0044] The term "natural gas" refers to any composition containing hydrocarbons (including at least methane). This includes "raw" compositions (before any treatment or washing) as well as any compositions that have been partially, substantially, or completely treated to reduce and / or eliminate one or more compounds (including, but not limited to, sulfur, carbon dioxide, water, mercury, and certain heavy aromatics).

[0045] The invention will now be better understood through the following description, which is provided by way of non-limiting example only and with reference to the accompanying drawings, in which:

[0046] Figure 1 A heat exchanger according to an embodiment of the present invention is illustrated schematically;

[0047] Figure 2 This is a three-dimensional schematic diagram of a first mixing device according to an embodiment of the present invention;

[0048] Figure 3 This is a schematic cross-sectional view of a first mixing device according to an embodiment of the present invention in a plane perpendicular to the plate of the exchanger;

[0049] Figure 4 This is a schematic cross-sectional view of the first and second mixing devices according to an embodiment of the present invention in a plane parallel to the plate of the exchanger;

[0050] Figure 5 This is a schematic cross-sectional view of the first and second mixing devices according to another embodiment of the present invention in a plane parallel to the plate of the exchanger;

[0051] Figure 6 The results of fluid flow simulations from a mixing device configured according to the prior art and a mixing device according to the present invention are shown;

[0052] Figure 7A method for liquefying a hydrocarbon stream according to an embodiment of the present invention is illustrated schematically;

[0053] Figure 8 A method for liquefying a hydrocarbon stream according to another embodiment of the present invention is illustrated schematically.

[0054] Figure 1 This is a cross-sectional view of a heat exchanger 1, which includes a stack of plates 2 (not shown) extending in two dimensions parallel to a plane defined by the longitudinal direction z and the lateral direction y. The plates 2 are arranged vertically parallel and spaced apart, thus forming a stack of passageways for fluid to exchange heat indirectly via the plates.

[0055] Preferably, each passage has a flattened parallelepiped shape. The gap between two successive plates is small compared to the length of each passage measured in the longitudinal direction z and the width measured in the lateral direction y.

[0056] The exchanger 1 may include more than 20 or even more than 100 plates, which together define a first set of first passages 10A and second passages 10B for guiding at least one first fluid F1 (passages 10B in... Figure 1 (not shown in the image), and a second set of passages 20 for guiding at least one second fluid F2. Figure 1 (Not shown in the diagram), the flow of the fluid generally occurs along the z-direction. Passages 10A and 10B may be arranged alternately, wholly or partially, and / or adjacent to all or some of the passages 20. The exchanger 1 may include a third set of passages or even more for the flow of one or more additional fluids. These sets of passages are stacked relative to each other to form a passage stack.

[0057] The sealing of passages 10A, 10B, and 20 along the edge of plate 2 is generally provided by lateral sealing strips and longitudinal sealing strips 4 attached to plate 2. The lateral sealing strips 4 do not completely seal passages 10A, 10B, and 20, but advantageously leave fluid inlet and outlet openings in the diagonally opposite corners of the passages.

[0058] The openings of the first set of passages 10A and 10B are arranged so that they overlap vertically, while the openings of the second set of passages 20 are arranged at opposite corners. The vertically placed openings are joined in semi-tubular manifolds 40, 45, 52, and 55, respectively, through which fluid is distributed to passages 10A, 10B, and 20 and discharged.

[0059] It should be noted that, except for Figure 1Other configurations for introducing and discharging fluid besides those shown. Therefore, the openings in the passages can be arranged at other locations along the width of the exchanger, particularly at the center of the exchanger width, and / or at other locations along the length of the exchanger. Figure 1 In the diagram, semi-tubular manifolds 52 and 45 are used to introduce fluid into exchanger 1, and semi-tubular manifolds 40 and 55 are used to discharge this fluid from exchanger 1.

[0060] In this alternative embodiment, the manifold supplying one fluid and the manifold discharging another fluid are located at the same end of the exchanger, so fluids F1 and F2 flow through exchanger 1 in opposite directions.

[0061] According to another alternative embodiment, the first fluid and the second fluid can also circulate in the same direction, wherein the device for supplying one fluid and the device for discharging the other fluid are located at opposite ends of the exchanger 1.

[0062] Preferably, when the exchanger 1 is operating, the z-direction is vertically oriented. The first fluid F1 flows vertically upwards overall. Other flow directions and routes for fluids F1 and F2 are obviously conceivable without departing from the scope of the invention.

[0063] It should be noted that, within the scope of this invention, one or more second fluids F2 with different properties may flow within the second set of passages 20.

[0064] Preferably, the first fluid F1 is a coolant, and the second fluid F2 is a heat transfer fluid.

[0065] The exchanger advantageously includes distribution corrugations 51 and 54, which are arranged in the form of corrugated sheets between two successive plates 2, extending from the inlet opening and the outlet opening. Distribution corrugations 51 and 54 ensure uniform distribution and recovery of fluid across the entire width of passages 10A, 10B, and 20.

[0066] Furthermore, passages 10A, 10B, and 20 advantageously include heat exchange structures arranged between plates 2. The purpose of these structures is to increase the heat exchange surface of the exchanger and to increase the exchange coefficient between fluids by making the flow more turbulent. In practice, the heat exchange structures come into contact with the fluid circulating in the passages and transfer heat to adjacent plates 2 by conduction. The heat exchange structures can be brazed to these adjacent plates, which increases the mechanical strength of the exchanger.

[0067] The heat exchange structures also serve as spacers between the plates 2, particularly when the exchanger is assembled by brazing, and to prevent any deformation of the plates when pressurized fluid is applied. These heat exchange structures also ensure that the fluid flow is guided within the passageways of the exchanger.

[0068] Preferably, these structures include heat exchange corrugations 11 that advantageously extend parallel to the width and length of the plate 2 across the passages 10A, 10B, 20, along the length of the distribution corrugations. Thus, the main portion of the length of the passages 10A, 10B, 20 of the exchanger forms the heat exchange section itself, which is lined with the heat exchange structure, the main portion being bounded by the distribution portion lined with distribution corrugations 51, 54.

[0069] Figure 1 A first passage 10A of a first group is shown, configured for the flow of a first fluid F1 in the form of a two-phase mixture, also referred to as a two-phase mixture. The first group includes multiple first passages 10A of this type, and multiple second passages 10B stacked on the first passages and having a structure similar to the first passages 10A. The first fluid F1 is separated into a first phase 61 and a second phase 62 in a separator device 6, which are respectively introduced into the exchanger 1 via separate first manifolds 30 and second manifolds 52. Preferably, the first phase 61 is a liquid, and the second phase 62 is a gas.

[0070] Then, the first phase 61 and the second phase 62 are mixed together by a first mixing device 3A arranged in at least one first passage 10A. Advantageously, a plurality of first passages 10A or even all passages 10A in the first group include a first mixing device 3A. Similarly, the first phase 61 and the second phase 62 are mixed together by a second mixing device 3B arranged in at least one second passage 10B. Advantageously, a plurality of second passages 10B or even all passages 10B in the first group include a second mixing device 3B. Semi-tubular manifolds 52 and 55 are fluidly connected to the inlets and outlets of passages 10A and 10B. A first manifold 30 is fluidly connected to at least one first inlet 311A, 311B of each of the first mixing device 3A and the second mixing device 3B. A second manifold 52 is fluidly connected to at least one second inlet 321A, 321B of each of the first mixing device 3A and the second mixing device 3B.

[0071] It should be noted that Figure 1 A mixing device 3A is shown positioned at a distance from the distribution area 51 of the exchanger 1. According to an alternative embodiment, the first mixing device 3A may be positioned directly after or alongside the distribution area, meaning the mixing device and the distribution area are a single unit. In the latter possibility, the mixing device forms a single-piece component, which can be manufactured by conventional machining or by additive manufacturing (i.e., by 3D printing, for example by laser sintering).

[0072] Figure 2This is a three-dimensional view of a first mixing device 3A housed in a first passage 10A, which is advantageously constructed of rods or bars. A second mixing device 3B may have all or some of the features described for the first device 3A.

[0073] The first mixing device 3A preferably extends across almost the entire or even the entire height of the first passage 10A into the cross section of the passage 10, such that the mixing device contacts each plate 2 forming the first passage 10A.

[0074] The first mixing device 3A is advantageously attached to the plate 2 by brazing.

[0075] The first mixing device 3A advantageously has an overall parallelepiped shape.

[0076] Preferably, the first mixing device 3A is a one-piece component, i.e., formed from a block or as a single piece. The first mixing device 3A can be manufactured by conventional machining or additive manufacturing. The first mixing device 3A may have a first dimension parallel to the longitudinal direction z in the range of 20 mm to 200 mm, and a second dimension parallel to the lateral direction y in the range of 100 mm to 1,400 mm.

[0077] The first mixing device 3A includes at least one lateral channel 31A, which is configured for the first phase 61 of the first fluid F1 to flow from at least one first inlet 311A. Preferably, the lateral channel 31A extends parallel to the lateral direction y.

[0078] The mixing device further includes a series of longitudinal channels 32A extending parallel to the longitudinal direction z and configured for the second phase 62 of the first fluid F1 to flow upward from the second inlet 321A to the second outlet 322A. The longitudinal channels 32A are arranged at successive positions along the lateral direction y. i y i+1 ...place.

[0079] Preferably, the lateral channel 31A extends across the entire second dimension, and / or the longitudinal channel 32A extends across the entire first dimension.

[0080] Preferably, the mixing device 3A includes at least one first inlet 311A ​​in fluid communication with a first manifold 30, and a second inlet 321A separate from (i.e., different from) the first inlet 311A ​​and in fluid communication with a second manifold 52. The first manifold 30 is fluidly connected to a first phase source 61, and the second manifold 52 is fluidly connected to another second phase source 62. The at least one first inlet 311A ​​and the at least one second inlet 321A are in fluid communication via at least one opening 34. The first and second inlets are advantageously formed by creating lateral and longitudinal channels at the lateral and longitudinal peripheral edges of the devices 3A and 3B.

[0081] Figure 2 The first phase 61 is introduced via an end of device 3A comprising a plurality of first inlets 311A. According to an advantageous embodiment, the first mixing device 3A includes at least one additional first inlet for the first phase 61 located at the opposite end of device 3A. Advantageously, these additional inlets are obtained by extending lateral channels 31A, 31B until these lateral channels appear at the opposite lateral edges of the exchanger 1. In this case, another first manifold 30 is arranged on the opposite side of the exchanger 1. Introducing the first phase 61 on either side of the mixing device allows for a reduction in the effect of pressure loss as the first phase flows in the lateral channels, which promotes a more uniform distribution of the two-phase mixture across the width of the exchanger.

[0082] Preferably, the first mixing device 3A includes a mixing volume located in a longitudinal channel 32A, which is downstream of the opening 34 in the flow direction of the first phase 61.

[0083] A lateral channel 31A is fluidly connected to at least one longitudinal channel 32A, such that when the first phase 61 flows in the lateral channel 31A and the second phase 62 flows in the longitudinal channel 32A, the first mixing device 3A dispenses a mixture, preferably a liquid / gas two-phase mixture F1, of the first phase 61 and the second phase 62 via a second outlet 322A of the channel 32A. Preferably, the longitudinal channel and / or the lateral channel are generally straight.

[0084] Channels 31A and 32A are advantageously shaped as longitudinal recesses within the mixing device 3. These channels preferably appear on the upper surface 3A and lower surface 3b of the mixing device 3a.

[0085] Preferably, channels 31A and 32A have a square or rectangular cross-section, but alternatively, they may take other shapes (circular, circular portions, etc.).

[0086] The opening 34 is advantageously a perforation 34 formed in the material of the device 3A, and preferably extends between the lateral channel 31A and the longitudinal channel 32A in a plane formed by the directions x and y, wherein the opening 34 can be tilted relative to the direction x, or preferably aligned with the vertical direction x. Preferably, the opening 34 has cylindrical symmetry, and more preferably is cylindrical.

[0087] Preferably, the at least one lateral channel 31A includes a bottom wall 3c, and the at least one longitudinal channel 32A includes a top wall 3d that extends opposite to the bottom wall 3c, and an opening 34 is perforated in the bottom wall of the lateral channel 31 and appears in the top wall of the longitudinal channel 32A.

[0088] Figure 3 yes Figure 2 The view of the mixing device 3A in a cross-sectional plane orthogonal to the lateral direction y and passing through the opening 34.

[0089] For convenience, mixing devices with the same geometry are usually arranged in the first group of passages 10A and 10B (especially longitudinal passages arranged at the same position along the lateral direction y).

[0090] At the outlet of each longitudinal channel, the flow of the two-phase mixture of the first fluid F1 preferably occurs in the longitudinal direction z, wherein the flow gradually expands across the width of the channel. Homogenization of these flows in each channel is achieved only beyond a certain distance covered by the mixture. This homogenization of the mixture F1 is lacking in the entire stack of channels 10A, 10B of the first group.

[0091] To address these issues, the present invention proposes arranging a first mixing device 3A and a second mixing device 3B respectively in the first passage 10A and the second passage 10B of the first group. These mixing devices have different configurations, wherein at least a portion, preferably all, of the longitudinal channel 32A of the first mixing device 3A is positioned along the lateral direction y at a location different from the position of the longitudinal channel 32B of the first mixing device 3A. It should be noted that the term "at least some" should be understood to refer to one or more or all of the longitudinal channels 32A in this series.

[0092] This allows the two-phase mixture of fluid F1 to be distributed at points that are differently distributed across the width of the exchanger. Therefore, by considering the assembly formed by the first passage 10A and the second passage 10B, the overall homogenization of the two-phase mixture experienced by the second fluid is improved. In fact, by considering that the outlets of longitudinal channel 32A and longitudinal channel 32B are arranged in the same plane, the distance between one channel and the next, measured in the lateral direction y, can be reduced. In the prior art, where two mixing devices have the same channel location, the distance between one channel and the next must be equal to the distance between the channels of each device. It should be noted that with this invention, better homogenization can be achieved without affecting or significantly affecting the fluid flow in each longitudinal channel.

[0093] This invention reduces, or even eliminates, the difference in mixing rate across the width of the exchanger after the mixture has traveled a shorter distance downstream of the mixing device. This improves heat exchange between the two-phase mixture and the second fluid F2, and thus improves the operation of the exchanger.

[0094] Furthermore, the mechanical strength of the exchanger has been improved during brazing or its operation. In fact, channels 32A and 32B are no longer positioned in a stacked manner within the exchanger stack, and the material deficiency generated in channels 32A and 32B is better distributed, making the stack robust. Additionally, thermal stress is reduced due to the better distribution of the two-phase mixture experienced by the second fluid.

[0095] Preferably, the first set of passages for the flow of the two-phase mixture includes a plurality of first passages 10A and a plurality of second passages 10B, which include a first mixing device and a second mixing device configured according to the invention. The first passages 10A and the second passages 10B are advantageously positioned alternately within the passage stack forming the exchanger.

[0096] Preferably, at least one passage 20 of the second group is arranged between at least one first passage 10A and at least one second passage 10B following said at least one first passage 10A. Specifically, the passage stack can have the following alternating pattern: first passage 10A, passage 20, second passage 10B, passage 20, first passage 10A, passage 20, etc. Therefore, the number of coolant passages is minimized. According to another possibility, the passage stack can have the following alternating pattern: first passage 10A, second passage 10B, passage 20, first passage 10A, second passage 10B, passage 20, etc.

[0097] The present invention enables better homogenization of the total refrigeration supply from the two-phase mixture to the second heat transfer fluid, and thus improves the performance of the exchanger.

[0098] Figure 4 andFigure 5 Embodiments of the first device 3A and the second device 3B according to the invention are shown. It should be noted that devices 3A and 3B are shown side-by-side in the same plane, but during operation, they are arranged in separate passages 10A and 10B stacked along the x-direction, preferably located at the same position along the longitudinal direction z. The positioning of the longitudinal passages 32A and 32B within devices 3A and 3B is schematically shown by vertical lines. Axis AA represents the longitudinal axis of symmetry of each passage 10A and 10B in the plane formed by directions y and z.

[0099] Figure 4 and Figure 5 The diagram schematically illustrates longitudinal channels in linear form. It should be noted that the position y in the lateral direction of each channel can be determined by considering the position of the center of each channel along the lateral direction y. i y i+1 y i+2 ...For example, by considering such... Figure 2 The channel shown is in the form of a parallelepiped or generally parallelepiped groove. The position of the channel along the y-direction corresponds to the position of the channel's axis of symmetry, which is equidistant from the side walls of the channel. Figure 2 As shown.

[0100] Preferably, the longitudinal channels 32A of the first mixing device 3A are separated from each other by a first constant distance D. A Furthermore, the longitudinal channels 32B of the second mixing device 3B are separated from each other by a second constant distance D. B Distance D A D B It is measured parallel to the longitudinal direction y.

[0101] Preferably, the first distance D A Second distance D B They are equal.

[0102] First distance D A and / or the second distance D B The range can be between 10mm and 40mm, preferably greater than or equal to 20mm and less than or equal to 30mm.

[0103] Preferably, the mixing devices 3A and 3B are each defined by two longitudinal edges 3e.

[0104] Preferably, the dimensions of the mixing devices 3A and 3B are determined to at least partially cover, and preferably completely cover, the longitudinal sealing strips 4, which seal these passages along the longitudinal direction z.

[0105] Therefore, mixing devices 3A and 3B have an effective width L yThe effective width is less than the distance between the two longitudinal edges 3e and corresponds to the width of the mixing device exposed to the fluid, i.e., the width of passage 10A or 10B. The mixing devices 3A and 3B have an effective width region L extending between the two ends 81. y and overlapping regions 80, which extend beyond pathways 10A and 10B and whose widths advantageously correspond to, for example, Figure 1 The width of the lateral sealing strip 4 is shown. This arrangement ensures the rigidity of the stack and better mechanical strength of the brazed components.

[0106] Preferably, each longitudinal channel 32A of the first mixing device 3A is inserted in the lateral direction y between two successive longitudinal channels 32B of the second mixing device 3B, or between the longitudinal channel 32B and the longitudinal edge 3e of the second mixing device 3B.

[0107] Preferably, the single longitudinal channel 32A of the first mixing device 3A is inserted in the lateral direction y between two successive longitudinal channels 32B of the second mixing device 3B, or between the longitudinal channel 32B and the lateral edge 3e of the second mixing device 3B.

[0108] Preferably, each pair of successive longitudinal channels 32B of the second mixing device 3B corresponds to the longitudinal channel 32A of the first mixing device 3A inserted between the pair of channels. Optionally, the longitudinal channel 32A of the first mixing device 3A is inserted between the longitudinal channel 32B of the second mixing device 3B and the lateral edge 3e.

[0109] Preferably, the series of longitudinal channels 32B of the second mixing device 3B are offset by a predetermined offset distance D relative to the series of longitudinal channels 32A of the first device 3A. y The predetermined offset distance is measured along the lateral direction y.

[0110] Preferably, the offset distance D y First distance D A Between 25% and 75%, preferably with an offset distance D y It is the first distance D A Approximately 50%. The expression "approximately" means 50% or roughly 50%, with variations around that value being greater or less than 10%.

[0111] According to Figure 4In this configuration, the first and second mixing devices have the same structure, with one mixing device rotated 180° relative to the other in the plane formed by directions y and z before being installed into its passage. The advantage of this configuration is that only one type of mixing device needs to be manufactured, and different distributions of longitudinal channels 32A and 32B can be obtained simply by rotating this device in the plane formed by directions y and z. Advantageously, distance D... A and D B They are equal, and the offset D y equals D A Half of the number of longitudinal channels 32A and 32B in the first and second mixing devices. The longitudinal channels 32A and 32B are arranged such that, for one of the mixing devices, the first longitudinal channel in this series is located at a distance D from one end of the effective area. A The last longitudinal channel 32A in this series is located at the opposite end 81 of the effective area, at a distance D. A At / 2, the opposite applies to the other mixing device.

[0112] Figure 5 An alternative embodiment is shown, wherein the longitudinal channels of the first passage 10A and the second passage 10B are arranged symmetrically with respect to the axis of symmetry AA of the exchanger. The advantage of this configuration is that the distribution points of the two-phase mixture remain symmetrically distributed across the width of the exchanger. Advantageously, the distance D... A and D B They are equal, and the offset D y equals D A Half of the first and second mixing devices. One of the mixing devices has an additional longitudinal channel relative to the other mixing device. The longitudinal channels 32A and 32B are arranged such that, for one of the mixing devices, the first longitudinal channel and the last longitudinal channel 32A in this series are located at a distance D from each opposite end 81 of the effective area. A For another mixing device, the first and last longitudinal channels in this series are located at opposite ends 81 from the effective area, at a distance D. A / 2. Effective width L of the mixing device. y It is the distance D A Multiples of.

[0113] According to a preferred embodiment, the first mixing device 3A and the second mixing device 3B are arranged in their respective passages 10A, 10B such that their lower surfaces 3b (where their longitudinal channels 32A, 32B appear) are oriented in the vertical direction x, or particularly as Figure 3 All the locations shown are oriented in a direction opposite to the vertical x-direction.

[0114] According to an alternative embodiment, at least one of these first mixing devices 3A has a lower surface 3b oriented in the opposite direction to the orientation of the lower surface 3b of at least one second mixing device 3B and / or at least one other first mixing device 3A; that is, at least one first mixing device is rotated 180° about an axis parallel to direction y before being arranged into its passage. This allows the flow of the two-phase mixture to be oriented toward certain adjacent passages 20 of the second group to facilitate heat exchange with certain heat transfer fluids rather than others. For example, it is conceivable that the lower surfaces 3b of the first and second mixing devices that are adjacent to each other in the passage stack have alternating orientations.

[0115] The above description was provided considering two configurations of the mixing device. It should be understood that three or more configurations can be implemented, and each includes one or more of the applicable features. In particular, the longitudinal channel of the additional mixing device is arranged in a different position along the lateral direction y than the positions of the first and second mixing devices. In particular, in the case of three different mixing devices, the exchanger will include a third mixing device 3C having a longitudinal channel 32C, wherein the longitudinal channels of the first mixing device 3A and the second mixing device 3B are inserted along the lateral direction y between two successive longitudinal channels 32C of the third device, or between the longitudinal channel 32C of the third device 3C and a longitudinal edge.

[0116] To illustrate the overall homogenization effect obtained using the present invention Figure 6 Simulation results of the propagation of a two-phase mixture in an exchanger are shown. The exchanger includes a conventional passage arrangement (configuration A) with mixing devices of the same type, and a passage arrangement (configuration B) with a first mixing device and a second mixing device configured according to the present invention.

[0117] In configuration A, each passage in the first group includes a mixing device in the form of a grooved rod. The grooved rod comprises a series of parallelepiped grooves spaced 30 mm apart, arranged sequentially as longitudinal channels, and a series of parallelepiped grooves as lateral channels. These parallelepiped grooves are fluidly connected to the longitudinal channels via a single opening for each longitudinal channel. The geometry of the opening is identical for all longitudinal channels. The longitudinal channels of each mixing device are arranged in the same number at the same positions along the lateral direction. i y i+1 ...place.

[0118] In configuration B, the first mixing device and the second mixing device are alternately arranged in the passages of the first set of passages of the exchanger. The first mixing device and the second mixing device are in the same slotted bar form as in configuration A, and specifically have a distance D between them. A=D B =30mm groove, in addition to the series of grooves forming the longitudinal channel of the second mixing device, this series of grooves is offset by a distance D relative to the series of grooves forming the longitudinal channel of the first mixing device. y =D A / 2.

[0119] In configurations A and B, serrated corrugations 11 (i.e., partially offset corrugations) are arranged at the outlet of the mixing device in each passage. These corrugations are 1 / 8" serrated (1" = 1 inch = 25.4 mm) (i.e., the serration length is 25.4 / 8 = 3.18 mm) and have a density of 24 fins per inch (1 inch = 25.4 mm) measured in the lateral direction y. The simulation assumes that for each serration change of the corrugations, the mixing rate is divided into two equal parts.

[0120] Figure 6 The diagram shows the dimensionless mass flow rate obtained over a propagation distance of 200 mm in the longitudinal direction z and the lateral direction y, after leaving the longitudinal channel, by averaging the flow rates across all paths of the first group of the exchanger. It can be seen that, in configuration B according to the invention, the variation in flow rate across the width of the exchanger is reduced.

[0121] Figure 7 and Figure 8 An example of implementing one or more switches according to the present invention is shown.

[0122] Figure 7 A method for liquefying a hydrocarbon stream 102, which is a second fluid F2, is schematically shown. The hydrocarbon stream may be natural gas, which may be pretreated before being introduced into the heat exchanger 1, for example, by separating at least one of the following components: water, carbon dioxide, sulfur compounds, methanol, and mercury.

[0123] Preferably, the hydrocarbon stream contains at least 60%, preferably at least 80%, of methane in mole fraction.

[0124] Hydrocarbon stream 102 and cooling stream 202 enter exchanger 1 via third inlet 25 and fourth inlet 21, respectively, to circulate in dedicated passages within the exchanger in a direction parallel to the longitudinal direction z, which is substantially vertical during operation. Hydrocarbon stream 102 circulates through a second set of passages 20 supplied by the third inlet 25. Cooling stream 202 circulates through a third set of passages arranged within the stack body forming exchanger 1. These streams exit via a third outlet 22 and a first outlet 23. The second and third sets of passages are arranged, in whole or in part, alternately and / or adjacent to all or part of the first set of passages 10A, 10B.

[0125] Advantageously, the fourth inlet 21 for the cooling flow 202 and the third inlet 25 for the hydrocarbon flow 102 are arranged such that the cooling flow 202 and optionally the hydrocarbon flow 102 flow downward in the same direction toward the second end 1b of the exchanger, which is located at a lower level than the first end 1a of the exchanger. Preferably, the first end 1a corresponds to the hot end of the exchanger 1, i.e., the inlet point of the exchanger, where the fluid is introduced at the highest temperature in the exchanger, and depending on the method, this inlet point can be either the fourth inlet 21 or the third inlet 25.

[0126] Hydrocarbon stream 102 can be introduced into exchanger 1 in a temperature range between -130°C and 40°C.

[0127] According to one possibility, hydrocarbon stream 102 is introduced into the exchanger in a completely gaseous or partially liquefied state within a temperature range between -80°C and -35°C.

[0128] According to another possibility, hydrocarbon stream 102 is introduced into exchanger 1 in a fully liquefied state within a temperature range of -130°C to -100°C.

[0129] The cooling flow 201 exiting the exchanger 1 expands through an expansion member T3 (such as a turbine, valve, or a combination of turbine and valve) to form a two-phase cooling flow 203 comprising a liquid and a gas phase. The two-phase cooling flow 203 forms the previously considered first fluid F1. At least a portion of the expanded two-phase cooling flow 203 is introduced into a separator member 27. The separator member can be any device suitable for separating the two-phase fluid into a predominantly gaseous flow on one hand and a predominantly liquid flow on the other.

[0130] A gas phase 62 is introduced via manifold 52, which supplies the gas to the second inlets 321A and 321B of the first mixing device 3A and the second mixing device 3B arranged in the first passage 10A and the second passage 10B of the first group. A liquid phase 61 is introduced via a first manifold 30, which supplies the liquid to the first mixing device 3A and the second mixing device 3B. Figure 7 The first inlets 311A ​​and 311B (not shown in the image) are the first entry points.

[0131] Preferably, the gas phase is introduced via an inlet (i.e., an inlet point in the exchanger) located in a region of the second end 1b corresponding to the cold end of the exchanger 1, at which the fluid is introduced at the lowest temperature of the fluid in the exchanger.

[0132] The two phases 61 and 62 of the two-phase flow 203 are recombine in the exchanger 1 and are distributed in the first passage 10A and the second passage 10B of the exchanger 1 in a liquid-gas mixture state. The first passage and the second passage are respectively provided with the first mixing device 3A and the second mixing device 3B according to the mixing device 3 of the present invention.

[0133] Preferably, the two-phase cooling flow 203 is introduced into the heat exchanger 1 at a first temperature T1 ranging from -120°C to -160°C, and exits the heat exchanger 1 at a second temperature T2 higher than the first temperature T1, preferably ranging from -35°C to -130°C.

[0134] According to another possibility, the two-phase cooling flow 203 is introduced into the heat exchanger 1 at a first temperature T1 ranging from -130°C to -80°C, and exits the heat exchanger 1 at a second temperature T2 higher than the first temperature T1, preferably ranging from -10°C to 50°C.

[0135] At least a portion of the two-phase cooling flow 203 flows upward through passages 10A and 10B and is vaporized by counter-current cooling of the natural gas 102 and the cooling flow 202. Thus, a cooled and / or at least partially liquefied hydrocarbon flow 101 is obtained at the outlet of the exchanger 1.

[0136] The vaporized cooling flow leaves the heat exchanger 1 via a second outlet 42 connected to manifold 55 so that it can be compressed by the compressor and then exchange heat with an external cooling fluid, such as water or air, in an indirect heat exchanger. Figure 1 (26 locations in the compressor) are cooled. The cooling flow pressure at the compressor outlet can range from 2 MPa to 9 MPa. The cooling flow temperature at the outlet of the indirect heat exchanger can range from 10°C to 45°C.

[0137] exist Figure 7 In the method described, the cooling flow is not divided into separate parts. However, in order to optimize the path in the exchanger 1, the cooling flow can also be divided into two or three parts, each of which expands at a different pressure level and is then sent to different stages of the compressor.

[0138] Preferably, the cooling stream 202 contains a hydrocarbon having at most 5 carbon atoms, preferably at most 3, and more preferably at most 2 carbon atoms.

[0139] Preferably, the cooling stream 202 is formed, for example, from a mixture of hydrocarbons and nitrogen, such as a mixture of methane, ethane and nitrogen, but may also contain propane, butane, isobutane, n-butane, pentane, isopentane, n-pentane and / or ethylene.

[0140] The mole fraction (%) of the components in the cooling stream can be:

[0141] - Nitrogen: 0% to 10%

[0142] -Methane: 20% to 70%

[0143] - Ethane: 30% to 70%

[0144] - Ethylene: 20% to 70%

[0145] -Propane: 0% to 20%

[0146] - n-Butane: 0% to 30%

[0147] -Isopentane: 0% to 20%

[0148] Optionally, the cooling stream may include ethylene as a substitute for ethane, and C4 and C5 compounds as substitutes for all or part of propane.

[0149] Preferably, the natural gas leaves the exchanger 1 at least partially liquefied at a temperature and a pressure equal to the inlet pressure of the natural gas (to achieve the closest possible pressure loss), preferably at a temperature at least 10°C higher than the bubble point temperature of the liquefied natural gas produced at atmospheric pressure (the bubble point temperature represents the temperature at which the first vapor bubble forms in liquid natural gas at a given pressure). For example, the natural gas leaves the exchanger 1 at a temperature in the range of -100°C to -162°C and a pressure in the range of 2 MPa to 7 MPa. Under these temperature and pressure conditions, depending on its composition, the natural gas typically does not remain liquid after expanding to atmospheric pressure.

[0150] Advantageously, the method for liquefying hydrocarbon streams according to the invention can be implemented in one or more additional refrigeration cycles upstream of the main refrigeration cycle described above, in order to pre-cool the hydrocarbon streams.

[0151] Figure 8 A method for liquefying hydrocarbon streams, such as natural gas, is schematically illustrated. This method includes an additional refrigeration cycle in which the natural gas is cooled to near its dew point using at least two different expansion levels to improve cycle efficiency. This additional refrigeration cycle is implemented via an additional cooling flow 300 in an additional heat exchanger 2, referred to as a precooling exchanger, which is arranged upstream of heat exchanger 1 in the flow direction of the hydrocarbon stream 110, and forms a liquefaction exchanger.

[0152] In this embodiment, the supply stream 110 arrives at a pressure, for example, between 2.5 MPa and 7 MPa, and a temperature, between 20°C and 60°C. When the supply stream 110 comprises a hydrocarbon mixture, such as natural gas, a cooling stream 202 and an additional cooling stream 300 enter an additional exchanger 2 to circulate therein in a downward direction along a parallel direction and in the same direction.

[0153] The cooled or even at least partially liquefied hydrocarbon stream 102 exits the precooling exchanger 2. Preferably, the hydrocarbon stream 102 exits in a gaseous or partially liquefied state, for example, within a temperature range of -35°C to -70°C. The cooling stream 202 can also exit the exchanger 2 completely condensed, for example, within a temperature range of -35°C to -70°C. Stream 102 is then introduced into the exchanger 1.

[0154] from Figure 8 As can be seen, stream 203 vaporizes in exchanger 1 and leaves the exchanger to be compressed by compressor K2, and is then cooled in indirect heat exchanger C2 by exchanging heat with an external cooling fluid such as water or air. The cooling stream originating from exchanger C2 then returns to auxiliary exchanger 2.

[0155] The additional cooling stream 300 can be formed from a mixture of hydrocarbons (such as a mixture of ethane and propane), but may also contain methane, ethylene, propylene, butane, and / or pentane. The molar fraction (%) of the components in the first coolant mixture can be:

[0156] - Ethane: 30% to 70%

[0157] -Propane: 30% to 70%

[0158] -Butane: 0% to 20%

[0159] In the additional exchanger 2, which is also a brazed plate fin type, at least two streams originating from the additional cooling flow 300 are drawn from the exchanger at at least two different outlet points and then expand to different pressure levels, generating partial two-phase expansion flows, each comprising a first phase and a second phase. At least a portion of these partial two-phase flows is introduced into corresponding separator components 24, 25, and 26.

[0160] exist Figure 8 In the embodiment, three portions of the additional cooling flow 300 in the first phase are successively extracted, also referred to as partial flow rates or flows 301, 302, and 303.

[0161] The gas and liquid phases separated by each separator component are introduced via separate inlets of the auxiliary heat exchanger 2 and recombine within a mixing unit (not shown) to form at least two coolant fluids introduced into a dedicated coolant passage in a liquid-gas mixture state. Alternatively, only the liquid phase is injected into the exchanger 2, and the gas phase is directed to the inlet of the compression stage of the compressor K1. These coolants are vaporized in the auxiliary exchanger 2 through heat exchange with the supply stream 110 and the cooling stream 200 and the auxiliary cooling stream 300.

[0162] Advantageously, at least two types of mixing devices 2 (such as those that can be arranged within the exchanger 1 according to the invention) are arranged in the additional exchanger. Thus, the additional exchanger includes at least two coolant passages, each coolant passage including a mixing device, which includes one or more features previously described for the first mixing device 3A and the second mixing device 3B.

[0163] The vaporized coolant is sent to different stages of compressor K1 for compression in its respective coolant passages, and then condenses in the condenser through heat exchange with an external cooling fluid (e.g., water or air). The stream originating from the condenser returns to the auxiliary heat exchanger 2. The pressure range of the first cooling stream at the outlet of compressor K1 can be between 2 MPa and 6 MPa. The temperature range of the auxiliary cooling stream at the outlet of condenser C1 can be between 10°C and 45°C.

[0164] Preferably, the coolant flows upward along the longitudinal direction z from one end 2b of the auxiliary exchanger 2 to the other end 2a. End 2b corresponds to the cold end of the auxiliary exchanger 2, where the coolant is introduced at the lowest temperature in the auxiliary exchanger 2.

[0165] Of course, the present invention is not limited to the specific examples described and shown in this application. Other alternative embodiments, within the capabilities of those skilled in the art, are conceivable without departing from the scope of the invention. For example, depending on the constraints imposed by the method to be implemented, other configurations for injecting / extracting fluid from the exchanger, other flow paths and directions of the fluid, other types of fluid, mixing devices, and other forms of lateral and longitudinal channels are obviously conceivable.

Claims

1. A heat exchanger (1) comprising a plurality of plates (2) arranged parallel to each other and parallel to a longitudinal direction (z), the plates (2) being stacked at a distance to define together at least one first set of passages (10A, 10B) and at least one second set of passages (20), the at least one first set of passages being configured for a first fluid (F1) to flow generally along the longitudinal direction (z), the at least one second set of passages being configured for a second fluid (F2) to flow in a heat exchange relationship with the first fluid (F1), the at least one first passage (10A) of the first set including a first mixing device (3A), and the at least one second passage (10B) of the first set including a second mixing device (3B), each of the first mixing device (3A) and the second mixing device (3B) comprising: - At least one lateral channel (31A, 31B) configured to allow the first phase (61) of the first fluid (F1) to flow from at least one first inlet (311A, 311B); - A series of longitudinal channels (32A, 32B) extending along the longitudinal direction (z), and each longitudinal channel being configured to allow the second phase (62) of the first fluid (F1) to flow from a second inlet (321A, 321B) to a second outlet (322A, 322B), the longitudinal channels being sequentially arranged in a lateral direction (y) orthogonal to the longitudinal direction (z); and - At least one opening (34) fluidly connects the at least one lateral channel (31A, 31B) to at least one longitudinal channel (32A, 32B), such that the first mixing device (3A) and the second mixing device (3B) are configured to dispense the mixture of the first phase (61) and the second phase (62) via the second outlets (322A, 322B) of their respective longitudinal channels (32A, 32B). The first mixing device (3A) is characterized in that its longitudinal channel (32A) is arranged at least partially in the lateral direction (y) at a position different from that of the longitudinal channel (32B) of the second mixing device (3B).

2. The heat exchanger as claimed in claim 1, characterized in that, The second mixing device (3B) includes two longitudinal edges (3e) extending parallel to the longitudinal direction (z), and each longitudinal channel (32A) of the first mixing device (3A) is inserted between two successive longitudinal channels (32B) of the second mixing device (3B) along the lateral direction (y), or between the longitudinal channel (32B) and the longitudinal edge (3e) of the second mixing device (3B).

3. The heat exchanger as described in claim 2, characterized in that, The single longitudinal channel (32A) of the first mixing device (3A) is inserted along the lateral direction (y) between two successive longitudinal channels (32B) of the second mixing device (3B), or between the longitudinal channel (32B) and the longitudinal edge (3e) of the second mixing device (3B).

4. The heat exchanger as described in any one of claims 1 to 3, characterized in that, The longitudinal channels (32A) of the first mixing device (3A) are separated from each other by a first constant distance (D). A Furthermore, the longitudinal channels (32B) of the second mixing device (3B) are separated from each other by a second constant distance (D). B ).

5. The heat exchanger as described in claim 4, characterized in that... The first constant distance (D) A ) and the second constant distance (D) B They are equal.

6. The heat exchanger as claimed in claim 4, characterized in that, The series of longitudinal channels (32B) of the second mixing device (3B) are offset relative to the series of longitudinal channels (32A) of the first mixing device (3A) by an offset distance (D) measured in the lateral direction (y). y ).

7. The heat exchanger as claimed in claim 6, characterized in that... This offset distance (D) y ) at the first constant distance (D A Between 25% and 75%.

8. The heat exchanger as claimed in claim 6, characterized in that... This offset distance (D) y ) is the first constant distance (D) A 50% of ).

9. The heat exchanger as claimed in claim 5, characterized in that, The series of longitudinal channels (32B) of the second mixing device (3B) are offset relative to the series of longitudinal channels (32A) of the first mixing device (3A) by an offset distance (D) measured in the lateral direction (y). y ).

10. The heat exchanger as claimed in claim 9, characterized in that... This offset distance (D) y ) at the first constant distance (D A Between 25% and 75%.

11. The heat exchanger as claimed in claim 9, characterized in that... This offset distance (D) y ) is the first constant distance (D) A 50% of ).

12. The heat exchanger as claimed in any one of claims 5 to 11, characterized in that, The first constant distance (D) A ) and / or the second constant distance (D) B The range is between 10mm and 40mm.

13. The heat exchanger as claimed in claim 12, characterized in that, The first constant distance (D) A ) and / or the second constant distance (D) B The range is greater than or equal to 20 mm and less than or equal to 30 mm.

14. The heat exchanger as claimed in claim 4, characterized in that, The first constant distance (D) A ) and / or the second constant distance (D) B The range is between 10mm and 40mm.

15. The heat exchanger as claimed in claim 14, characterized in that, The first constant distance (D) A ) and / or the second constant distance (D) B The range is greater than or equal to 20 mm and less than or equal to 30 mm.

16. The heat exchanger according to any one of claims 1 to 3, 5 to 11, 13 to 15, characterized in that, Each of the first passage (10A) and the second passage (10B) has a longitudinal axis of symmetry (AA') extending parallel to the longitudinal direction (z), and the longitudinal channels (32A, 32B) of each first mixing device (3A) and second mixing device (3B) are arranged symmetrically with respect to the longitudinal axis of symmetry (AA').

17. The heat exchanger as claimed in claim 4, characterized in that, Each of the first passage (10A) and the second passage (10B) has a longitudinal axis of symmetry (AA') extending parallel to the longitudinal direction (z), and the longitudinal channels (32A, 32B) of each first mixing device (3A) and second mixing device (3B) are arranged symmetrically with respect to the longitudinal axis of symmetry (AA').

18. The heat exchanger as claimed in claim 12, characterized in that, Each of the first passage (10A) and the second passage (10B) has a longitudinal axis of symmetry (AA') extending parallel to the longitudinal direction (z), and the longitudinal channels (32A, 32B) of each first mixing device (3A) and second mixing device (3B) are arranged symmetrically with respect to the longitudinal axis of symmetry (AA').

19. The switch as claimed in any one of claims 1 to 3, 5 to 11, and 13 to 15, characterized in that, After the position of the longitudinal channel (32B) of the second mixing device (3B) along the lateral direction (y) is rotated 180° in the plane defined by the lateral direction (y) and the longitudinal direction (z), it coincides with the position of the longitudinal channel (32A) of the first mixing device (3A) along the lateral direction (y).

20. The switch as claimed in claim 4, characterized in that, After the position of the longitudinal channel (32B) of the second mixing device (3B) along the lateral direction (y) is rotated 180° in the plane defined by the lateral direction (y) and the longitudinal direction (z), it coincides with the position of the longitudinal channel (32A) of the first mixing device (3A) along the lateral direction (y).

21. The switch as claimed in claim 12, characterized in that, After the position of the longitudinal channel (32B) of the second mixing device (3B) along the lateral direction (y) is rotated 180° in the plane defined by the lateral direction (y) and the longitudinal direction (z), it coincides with the position of the longitudinal channel (32A) of the first mixing device (3A) along the lateral direction (y).

22. The heat exchanger according to any one of claims 1 to 3, 5 to 11, 13 to 15, 17 to 18, and 20 to 21, characterized in that, The switch includes a plurality of alternating first paths (10A) and second paths (10B), at least one path (20) of the second group being arranged between at least one first path (10A) and at least one second path (10B) following the at least one first path (10A).

23. The heat exchanger as claimed in claim 4, characterized in that, The switch includes a plurality of alternating first paths (10A) and second paths (10B), at least one path (20) of the second group being arranged between at least one first path (10A) and at least one second path (10B) following the at least one first path (10A).

24. The heat exchanger as claimed in claim 12, characterized in that, The switch includes a plurality of alternating first paths (10A) and second paths (10B), at least one path (20) of the second group being arranged between at least one first path (10A) and at least one second path (10B) following the at least one first path (10A).

25. The heat exchanger as claimed in claim 16, characterized in that, The switch includes a plurality of alternating first paths (10A) and second paths (10B), at least one path (20) of the second group being arranged between at least one first path (10A) and at least one second path (10B) following the at least one first path (10A).

26. The heat exchanger as claimed in claim 19, characterized in that, The switch includes a plurality of alternating first paths (10A) and second paths (10B), at least one path (20) of the second group being arranged between at least one first path (10A) and at least one second path (10B) following the at least one first path (10A).

27. The heat exchanger according to any one of claims 1 to 3, 5 to 11, 13 to 15, 17 to 18, 20 to 21, 23 to 26, characterized in that, The lateral channels (31A, 31B) and / or longitudinal channels (32A, 32B) of the first mixing device (3A) and the second mixing device (3B) are straight.

28. The heat exchanger as claimed in claim 22, characterized in that, The lateral channels (31A, 31B) and / or longitudinal channels (32A, 32B) of the first mixing device (3A) and the second mixing device (3B) are straight.

29. The heat exchanger according to any one of claims 1 to 3, 5 to 11, 13 to 15, 17 to 18, 20 to 21, 23 to 26, and 28, characterized in that, The first mixing device (3A) and the second mixing device (3B) each include a series of lateral channels (31A, 31B) that extend along the lateral direction (y) and are sequential to each other along the longitudinal direction (z).

30. The heat exchanger as claimed in claim 27, characterized in that, The first mixing device (3A) and the second mixing device (3B) each include a series of lateral channels (31A, 31B) that extend along the lateral direction (y) and are sequential to each other along the longitudinal direction (z).

31. A method for liquefying a hydrocarbon-containing stream (102) as a second fluid (F2), said method implementing at least one heat exchanger (1) as claimed in any one of claims 1 to 30, and comprising the following steps: a) Introduce the hydrocarbon-containing stream (102) into the second set of pathways (20); b) Introduce the cooling flow (202) into the third set of passages of the heat exchanger (1); c) Discharge the cooling flow (201) from the heat exchanger (1) and expand the cooling flow (201) to at least one pressure level to generate at least one two-phase cooling flow (203) as a first fluid (F1); d) Separate at least a portion of the two-phase cooling flow (203) originating from step c) into a second phase (62) and a first phase (61), wherein the first phase (61) is a liquid phase and the second phase (62) is a gas phase; e) At least a portion of the second phase (62) and at least a portion of the first phase (61) are introduced into each of the first passage (10A) and the second passage (10B) of the first group via separate inlets (311A, 321A, 311B, 321B) of the first passage (10A) and the second passage (10B). f) The phases (61, 62) introduced in step e) are fed into the first mixing device (3A) and the second mixing device (3B) so that the first fluid (F1) as a mixture of the first phase (61) and the second phase (62) is obtained at the outlet of each of the first mixing device (3A) and the second mixing device (3B); g) By exchanging heat with at least the hydrocarbon-containing stream (102), at least a portion of the first fluid (F1) originating from step f) is vaporized in the first passage (10A) and the second passage (10B), thereby obtaining a cooled and / or at least partially liquefied hydrocarbon stream (101) at the outlet of the heat exchanger (1).

32. The method of claim 31, wherein the hydrocarbon is natural gas.

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