EP3254045B1 - Heat exchanger comprising a liquid-refrigerant distribution device - Google Patents

Description

The present invention relates to a heat exchanger comprising a dispensing device, configured to dispense a refrigerant in the heat exchanger, according to the title of claim 1. The heat exchanger may in particular be a vaporizer used in a heat exchanger. cryogenic distillation air separation column for vaporizing a column bottom liquid, for example liquid oxygen, by heat exchange with a caloric gas, for example air or nitrogen.

The present invention finds particular application in the field of gas separation by cryogenics, in particular the separation of air by cryogenics (known by the acronym "ASU" for air separation unit) exploited for the production of oxygen gas under pressure. In particular, the present invention can be applied to a heat exchanger which vaporizes a liquid flow, for example oxygen, nitrogen and / or argon by heat exchange with a gas.

If the heat exchanger is in the tank of a distillation column, it can constitute a vaporizer operating as a thermosiphon for which the exchanger is immersed in a bath of liquid descending the column or a vaporizer operating in vaporization with a film fed directly by the liquid falling from the column and / or by a recirculation pump.

The technology commonly used for these phase change exchangers is that of brazed plate and finned aluminum exchangers, which make it possible to obtain very compact members with a large exchange surface. These exchangers consist of plates between which fins are inserted, thus forming a stack of vaporization passages and condensation passages, one intended to vaporize refrigerant and the others to condense a caloric gas.

WO-2011110782 discloses a dispensing device comprising parallel plates, which define passages for the refrigerant, and a plurality of fins which extend in each passage and which have orifices for distributing the refrigerant in the lateral direction. The document WO 2011/110782 discloses a heat exchanger according to the preamble of claim 1.

However, in a dispensing device of the prior art, the distribution of the refrigerant in the lateral direction is not perfectly uniform. However, when areas of the exchanger do not receive enough refrigerant, solid deposition of impurities can occur by dry vaporization. Such solid deposits of impurities induce a risk of explosion under certain operating conditions of the heat exchanger.

A known solution of the document EP-A-0130122 is to drill holes in the parallel plates of the dispensing device to achieve a rough predistribution of the refrigerant liquid along the passages for said liquid. However, the number of orifices arranged along the heat exchanger is limited so as not to complicate its manufacture or to weaken its structure and the effect of uniformization of the distribution of the liquid remains insufficient.

The present invention is intended in particular to solve, totally or partially, the problems mentioned above, by providing a dispensing device in which the distribution of the refrigerant is as uniform as possible.

For this purpose, the subject of the invention is a heat exchanger configured for transferring heat from at least one heat-generating fluid, for example nitrogen, to at least one refrigerant, for example oxygen, the heat exchanger comprising at least plates arranged parallel to each other so as to define a first series of passages configured to channel refrigerant liquid generally in a longitudinal direction, extending in the vertical direction during operation, each passage being defined between two successive plates, and a second series of passages configured to channel a circulating fluid globally in the longitudinal direction, each passage being defined between two successive plates, the passages of the second series being interposed between two passages of the first series, at least one connected refrigerant inlet to discharge the refrigerant only into the passages of the first series and means of distribution, located in the upper end of the exchanger in passages of the first series only, comprising
fins extending in one or even each passage of the first series generally in a lateral direction which is orthogonal to the longitudinal direction and which is parallel to the plates, each passage of the first series housing a plurality of fins succeeding one another along the longitudinal direction each fin having orifices configured to allow flow of the refrigerant;
at least one fin having an upper portion and a lower portion, the altitude of the upper portion being greater than the altitude of the lower portion when the dispensing device is in use and the longitudinal direction extends in the vertical direction,
said at least one lower portion and the plate secured to said at least one lower portion defining at least one distribution channel configured to channel refrigerant in the lateral direction,
the orifices of said at least one fin being formed by overflow openings in said at least one upper portion, the overflow openings being configured so that the refrigerant flows through the overflow openings when said at least one channel of distribution is full of refrigerant.

In other words, the or each distribution channel forms a kind of gutter extending between the overflow openings and an intersection of the lower portion and the plate secured to this lower portion. The or each distribution channel is generally horizontal when the dispensing device is in use.

Thus, the cooperation of the or each distribution channel with the overflow openings of the fin (s) allows to distribute the refrigerant as evenly as possible in the lateral direction, which limits or even avoids the risk of solid deposition of impurities in the heat exchanger.

The plates extend in two dimensions, length and width, respectively in the longitudinal direction and the lateral direction. In each passage, the fins have elongated shapes and they extend along the width (lateral direction) of the two successive plates.

The longitudinal direction is vertical when the dispensing device is in use. The refrigerant flows globally in the longitudinal direction and by gravity. So the refrigerant flows globally vertically and downward.

According to a variant of the invention, the dispensing device can comprise a number of plates greater than 20, or even greater than 100. These plates thus form a stack of plates, between which are defined passages of refrigerant liquid, possibly alternating with ducts for the circulating fluid. The dispensing device may have a number of refrigerant passages greater than 10, or even greater than 50.

In use, the dispensing device is traversed by the refrigerant. The dispensing device has i) an upstream portion configured for the refrigerant inlet, and ii) a downstream portion configured for the refrigerant outlet. The fins extend between this upstream part and this downstream part.

According to a variant of the invention, each passage has a parallelepipedal and flat shape. As each passage has a flat shape, the gap between two successive plates is small in front of the length and the width of each successive plate. Preferably, all or part of the fins extends from one plate to the next plate. In other words, these fins are in contact with the two plates. This construction makes it possible to braze the fins on the two plates, which increases the mechanical strength of the dispensing device.

In the present application, the term "following" means that a direction is substantially parallel or substantially collinear with another direction or plane.

• i) par une ailette ayant des ouvertures de débordement,
• ii) par la plaque solidarisée à la portion inférieure de ladite ailette ayant des ouvertures de débordement, et
• iii) par l'ailette située immédiatement en amont de ladite ailette ayant des ouvertures de débordement.

According to one embodiment of the invention, the volume of a respective distribution channel is less than 15%, preferably less than 10%, of the total volume defined:

• i) by a fin having overflow openings,
• ii) by the plate secured to the lower portion of said fin having overflow openings, and
• iii) by the fin immediately upstream of said fin having overflow openings.

Thus, such a volume distribution channel prevents fins having overflow openings generate too high pressure drop. A low pressure drop avoids reducing the flow of refrigerant through the fins having overflow openings, which optimizes the regulation of this flow. The fins having overflow openings therefore rather fulfill a function of distribution of the refrigerant, generating only a small loss of load. Each distribution channel is defined by at least a lower portion and the plate secured to said at least a lower portion.

According to one embodiment of the invention, the overflow openings are distributed on a fin uniformly in the lateral direction.

Thus, uniformly distributed overflow openings maximize the uniformity of the refrigerant distribution. Alternatively, some overflow openings may be non-uniformly distributed in the lateral direction.

• pour numérateur, la superficie totale des ouvertures de débordement situées dans une ailette ayant des ouvertures de débordement, et
• pour dénominateur, la superficie totale d'une face de ladite ailette ayant des ouvertures de débordement,

est compris entre 10% et 50%, de préférence entre 20% et 40%.According to one embodiment of the invention, an opening report having:

• for numerator, the total area of overflow openings in a fin with overflow openings, and
• denominator, the total area of a face of said fin having overflow openings,

is between 10% and 50%, preferably between 20% and 40%.

Thus, such an opening ratio helps to minimize the pressure drop generated by the fins having overflow openings while ensuring adequate flow in the dispensing device.

According to one embodiment of the invention, each overflow opening has an area of between 1.5 mm ² and 10.0 mm ² , preferably between 2.0 mm ² and 5.0 mm ² .

Thus, such an area avoids completely flooding each overflow opening, which helps not to reduce the flow of refrigerant through each fin.

According to a variant of the invention, overflow openings have ellipse shapes, for example circular. Thus, such a shape has a width of the overflow opening which increases gradually, which limits the height of the refrigerant when the flow of refrigerant increases.

According to a variant of the invention, overflow openings have triangular shapes pointing towards said at least one lower portion. Thus, such a shape has a width of the overflow opening which increases gradually, which limits the height of the refrigerant when the flow of refrigerant increases.

According to one embodiment of the invention, an interval, measured along the lateral direction, between two successive overflow openings is between 1 mm and 6 mm.

Thus, such an interval helps to ensure a uniform distribution of the refrigerant in the lateral direction, while minimizing the pressure drop generated by the fins having overflow openings.

According to a variant of the invention, said interval is constant for the overflow openings of at least one fin.

Thus, such an interval contributes to maximizing the uniformity of the refrigerant distribution along the lateral direction.

According to one embodiment of the invention, a minimum distance between i) an overflow opening and ii) the plate secured to said at least one lower portion is between 1 mm and 4 mm, the minimum distance preferably being the same. for the majority or all of the overflow openings of a respective fin.

Thus, such a minimum distance allows the distribution channel to have a relatively large volume, which makes it possible to limit the number fins having overflow openings in the dispensing device.

According to one embodiment of the invention, several fins have respective upper portions having overflow openings.

In other words, there are several stages of distribution of the refrigerant, which helps to maximize the uniformity of this distribution.

According to one embodiment of the invention, the overflow openings present in a fin are positioned offset in the lateral direction relative to the overflow openings present in the neighboring vane.

Thus, such an offset between overflow openings contributes to increasing the uniformity of the refrigerant distribution along the lateral direction.

According to one embodiment of the invention, said offset between the overflow openings present in two neighboring fins represents between 40% and 60% of the length of said gap.

In other words, the overflow openings of two successive fins in the longitudinal direction are arranged substantially staggered.

Thus, such a value of the offset between overflow openings contributes to maximizing the uniformity of the refrigerant distribution along the lateral direction.

According to one embodiment of the invention, at least one fin has a flat shape and extends to said two successive plates and obliquely to each of said two successive plates so as to form, in section in a plane perpendicular to the plates and in the lateral direction, an acute oblique angle, the oblique angle preferably being between 30 ° and 60 °, more preferably between 40 ° and 50 °.

Thus, such a flat and oblique blade is relatively compact and easy to assemble with the plates.

According to one embodiment of the invention, each fin has, parallel to the longitudinal direction, a length of between 4 mm and 10 mm, and in which each fin has, parallel to the direction lateral, a width of between 4 mm and 10 mm, each fin may for example have a length and an equal width.

Thus, such a length and such a width can incorporate a large number of fins in the dispensing device, which increases the uniformity of the distribution of the refrigerant.

According to a variant of the invention, each fin has a fixing portion which is fixed to a plate, for example by brazing.

Thus, such a fixing portion can simply assemble each fin plates.

According to a variant of the invention, at least one, preferably each, overflow opening is defined by a through orifice. Alternatively, at least one overflow opening may be defined by a notch extending to an edge of the corresponding fin.

According to one embodiment of the invention, the dispensing device comprises at least one fin having orifices and placed upstream of the fin (s) having overflow openings, the orifices being distributed in the lateral direction, the number of overflow openings per fin being greater than 3 times, preferably 5 times, the number of orifices per fin.

Thus, the fins having orifices can fulfill a function of controlling the flow rate of the refrigerant entering the distribution device, generating a high pressure drop, whereas the fins having overflow openings rather fulfill a distribution function, generating only a small loss of load. This limits the number of components to be assembled in the dispensing device, because the fins having orifices dispense with providing a perforated bar like that of WO-2011110782 to generate a high pressure drop.

According to a variant of the invention, at least two fins having orifices, the number of orifices per fin increasing in the direction from upstream to downstream.

Thus, these fins having orifices make it possible to control as well as possible the flow rate of the refrigerant liquid entering the dispensing device.

According to one variant of the invention, the interval between two successive orifices, measured along the lateral direction of the fin having the most upstream orifices, is between 40 mm and 60 mm, and in which the interval between two successive orifices, measured in the lateral direction, of the fin having the most downstream orifices is between 6 mm and 20 mm.

Thus, the fin having the orifices located furthest upstream has the least orifices, while the fin having the orifices situated furthest downstream has the most orifices; the fins having overflow openings being located downstream of the fin having orifices located furthest downstream.

Thus, the pressure drop generated by the fins having orifices decreases from upstream to downstream, while increasing the uniformity of the distribution of the refrigerant liquid.

According to a variant of the invention, at least one fin may have, in addition to overflow openings, at least one bleed hole which is provided at the bottom of the lower portion. The distribution channel is then formed of several sections separated two by two by a purge hole through which the refrigerant can flow. Such a purge hole makes it possible to empty the distribution channel. Advantageously, the area of the or each bleed hole is smaller than the area of an overflow opening. Thus, the flow through the bleed hole has a relatively low flow rate, which avoids disrupting the flow by each overflow opening near the bleed hole.

According to a variant of the invention, which the total area of the openings, or even overflow openings, for a given fin increases in the longitudinal direction, preferably by increasing the number and / or the area of the openings.

In this way, the more the liquid goes down in the dispensing means, the smaller the spacing between the openings. Initially, if the liquid is poorly distributed, it is forced to flow laterally to the adjacent openings of the same fin. The longer the distance between two openings, the more redistribution across the width is effective.

• mettre en oeuvre un dispositif de distribution selon l'invention,
• canaliser du liquide frigorigène dans chaque passage et globalement suivant une direction longitudinale,
• permettre l'écoulement du liquide frigorigène par les orifices des ailettes ayant des orifices,
• emplir chaque canal de répartition de sorte que du liquide frigorigène s'écoule par les ouvertures de débordement.

On the other hand, the subject of the present invention is a dispensing method for dispensing a refrigerant liquid in a heat exchanger, the dispensing method comprising the steps of:

• implement a dispensing device according to the invention,
• channeling refrigerant in each passage and generally in a longitudinal direction,
• allow the flow of the refrigerant through the orifices of the fins having orifices,
• fill each distribution channel so that refrigerant flows through the overflow openings.

Furthermore, the subject of the present invention is a heat exchanger, configured to transfer heat from at least one heat-generating fluid, for example dinitrogen, to at least one refrigerant, for example oxygen, the heat exchanger. comprising at least one heat exchange unit, at least one refrigerant inlet, the heat exchanger being characterized in that it comprises a dispensing device according to any one of the preceding claims, the dispensing device being arranged to supply the refrigerant unit with the heat exchange unit.

Thus, such a heat exchanger limits or even avoids the risk of solid deposition of impurities in the heat exchanger, so the risk of explosion under certain operating conditions.

The embodiments and variants mentioned above may be taken individually or in any technically permissible combination.

• la figure 1 est une vue schématique en coupe, dans un plan perpendiculaire à la direction latérale, d'une partie d'un dispositif de distribution conforme à un premier mode de réalisation de l'invention ;
• la figure 2 est une vue schématique en coupe, suivant le plan II à la figure 1 qui est parallèle à la direction longitudinale et à la direction latérale, de la partie du dispositif de distribution de la figure 1 ;
• la figure 3 est une vue schématique en coupe, dans un plan perpendiculaire à la direction latérale, d'une partie d'un échangeur de chaleur comprenant le dispositif de distribution conforme au premier mode de réalisation de l'invention ;
• la figure 4 est une vue similaire à la figure 1 illustrant le fonctionnement du dispositif de distribution de la figure 3 ;
• la figure 5 est une vue similaire à la figure 2 illustrant le fonctionnement du dispositif de distribution de la figure 3 ;
• les figures 6 et 7 sont des vues similaires respectivement aux figures 1 et 2 et illustrant une partie d'un dispositif de distribution conforme à un deuxième mode de réalisation de l'invention ;
• les figures 8 et 9 sont des vues similaires respectivement aux figures 1 et 2 et illustrant une partie d'un dispositif de distribution conforme à un troisième mode de réalisation de l'invention ;
• la figure 10 est une vue similaire à la figure 1 et illustrant une partie d'un dispositif de distribution conforme à un quatrième mode de réalisation de l'invention ;
• la figure 11 est une vue similaire à la figure 10 et illustrant une partie d'un dispositif de distribution conforme à un cinquième mode de réalisation de l'invention ;
• la figure 12 est une vue similaire à la figure 10 et illustrant une partie d'un dispositif de distribution conforme à un sixième mode de réalisation de l'invention ;
• la figure 13 est une vue similaire à la figure 1 et illustrant une partie d'un dispositif de distribution conforme à un septième mode de réalisation de l'invention ;
• la figure 14 est une vue similaire à la figure 1 et illustrant une partie d'un dispositif de distribution conforme à un huitième mode de réalisation de l'invention ; et
• la figure 15 illustre un procédé de distribution conforme à l'invention.

The present invention will be well understood and its advantages will also emerge in the light of the description which follows, given solely by way of nonlimiting example and with reference to the appended drawings, in which:

• the figure 1 is a schematic sectional view, in a plane perpendicular to the lateral direction, of a portion of a dispensing device according to a first embodiment of the invention;
• the figure 2 is a schematic sectional view, according to plan II to figure 1 which is parallel to the longitudinal direction and the lateral direction, of the part of the distribution device of the figure 1 ;
• the figure 3 is a schematic sectional view, in a plane perpendicular to the lateral direction, of a portion of a heat exchanger comprising the dispensing device according to the first embodiment of the invention;
• the figure 4 is a view similar to the figure 1 illustrating the operation of the distribution device of the figure 3 ;
• the figure 5 is a view similar to the figure 2 illustrating the operation of the distribution device of the figure 3 ;
• the Figures 6 and 7 are similar views respectively to Figures 1 and 2 and illustrating a portion of a dispensing device according to a second embodiment of the invention;
• the Figures 8 and 9 are similar views respectively to Figures 1 and 2 and illustrating a portion of a dispensing device according to a third embodiment of the invention;
• the figure 10 is a view similar to the figure 1 and illustrating a portion of a dispensing device according to a fourth embodiment of the invention;
• the figure 11 is a view similar to the figure 10 and illustrating a portion of a dispensing device according to a fifth embodiment of the invention;
• the figure 12 is a view similar to the figure 10 and illustrating a portion of a dispensing device according to a sixth embodiment of the invention;
• the figure 13 is a view similar to the figure 1 and illustrating a portion of a dispensing device according to a seventh embodiment of the invention;
• the figure 14 is a view similar to the figure 1 and illustrating a portion of a dispensing device according to an eighth embodiment of the invention; and
• the figure 15 illustrates a dispensing method according to the invention.

The Figures 1, 2 and 3 illustrate a dispensing device 1 which is configured to dispense a refrigerant F1, in this case liquid oxygen, into a heat exchanger 2. The heat exchanger 2 is configured to transfer heat from a fluid calorigen F2, here nitrogen gas, to the refrigerant, here oxygen. Before the heat transfer, the refrigerant F1 ( figure 3 ) is in a holding tank 3 belonging to the heat exchanger 2.

The dispensing device 1 comprises plates 11, 12, 13, 14 and the like which are arranged parallel to each other. The dispensing device 1 comprises a number of stacked plates approximately equal to 200. Each of the plates 11, 12, 13, 14 extends along two dimensions, respectively its length and its width, which are respectively defined in a longitudinal direction X and a lateral direction Y.

The lateral direction Y is orthogonal to the longitudinal direction X and is parallel to the plates 11, 12, 13, 14. The longitudinal direction X is vertical when the dispensing device 1 is in use. The refrigerant F1 flowing generally in the longitudinal direction X and gravity. Thus the refrigerant F1 flows globally vertically and in the downward direction.

The plates 11, 12, 13, 14 are arranged to define passages 20, 30 and the like which are configured to channel the refrigerant F1 generally in the longitudinal direction X. Each passage 20 or 30 is defined between two successive plates 11 , 12, 13, 14. Each passage 20, 30 has a parallelepipedal and flat shape. The distance between two successive plates 11 and 12 is small in front of the length (along X) and width (along Y) of each successive plate 11 or 12. In the heat exchanger 2, the passages 20, 30 of refrigerant F1 alternate with parallelepipedic and flat shaped passages not shown for the circulating fluid.

The dispensing device 1 further comprises fins 21, 22, 23, 24 and 31, 32, 33, 34, which extend respectively in each passage 20 and 30 generally in the lateral direction Y. The fins 21, 22, 23, 24 extend in the passage 20, while the fins 31, 32, 33, 34 extend in the passage 30. In each passage 20 or 30, the fins 21, 22, 23, 24, 31, 32, 33 and 34 have elongate shapes and they extend in the lateral direction Y of the two successive plates 11 and 12 or 13 and 14.

Each fin 21, 22, 23, 24, 31, 32, 33 or 34 has a flat shape and extends to the two successive plates 11 and 12 or 13 and 14. Each fin 21 or equivalent extends obliquely to each two successive plates 11 and 12 or 13 and 14 so as to form, in section in a plane perpendicular to the plates and the lateral direction Y (here the plane of the figure 1 ), an oblique angle A21 which is acute. The oblique angle A21 is here 45 degrees.

Each fin 21 or equivalent has, parallel to the longitudinal direction X, a length X21 which is here equal to 5 mm. Each fin 21 or equivalent has, parallel to the lateral direction Y, a width Y21 which is here equal to 5 mm, thus equal to the length X21. Each fin 21 or equivalent here has a fastening portion 21.5 which is flat and is soldered to a respective plate 11 or equivalent. All the fins 21, 22, 23, 24 extend from a plate 11 to the successive plate 12. In other words, these fins 21, 22, 23, 24 are in contact with the two plates 11 and 12. The fins 21, 22, 23, 24 are brazed on the two plates 11 and 12.

Each passage 20 or 30 here houses four fins, respectively 21, 22, 23, 24 and 31, 32, 33, 34, which follow one another in the longitudinal direction X. Each fin 21 or equivalent has orifices 40, which are configured to allow the flow of the refrigerant F1 through the respective fin 21 or equivalent.

In the example of Figures 1 to 5 each fin 21, 22, 23, 24, 31, 32, 33 or 34 has an upper portion 21.1 and the like and a lower portion 21.2 and the like. When the dispensing device is in use ( figures 4 and 5 ), the altitude of the upper portion 21.1 is greater than the altitude of the lower portion 21.2.

Each lower portion 21.2 or equivalent and the respective plate, 11 or equivalent, secured to the lower portion 21.2 define a distribution channel 42, which is configured to channel refrigerant F1 in the lateral direction Y.

In the example of Figures 1 to 5 , the orifices 40 of each fin 21 or equivalent are formed by overflow openings 40 which are located in each respective upper portion 21.1 or equivalent. All the fins 21 and the like have respective upper portions 21.1 and the like which have overflow openings 40. For obvious reasons of clarity, all the overflow openings 40 are not referenced on them. Figures 1 to 5 .

The overflow openings 40 of each fin 21 or equivalent are configured so that the refrigerant F1 flows through the overflow openings 40 when the distribution channel 42 is full of refrigerant F1.

All overflow openings 40 here have triangular shapes pointing to each respective lower portion 21.2. The overflow openings 40 are here distributed over a respective fin 21 or equivalent in a uniform manner along the lateral direction Y.

A gap D40, measured along the lateral direction, between two successive overflow openings 40, is here constant and equal to 4 mm for the overflow openings 40 of each fin 21 or equivalent.

Furthermore, a minimum distance H40 between i) an overflow opening 40 and ii) the plate 11 secured to the respective lower portion 21.2 is equal to 3 mm. This minimum distance H40 is the same (constant) for all the overflow openings 40 of a respective fin 21 or equivalent.

In the example of Figures 1 to 5 , the overflow openings 40 present in a fin 21 are positioned offset in the lateral direction Y relative to the overflow openings 40 present in the neighboring vane 22. The offset D40 / 2 between the overflow openings 40 present in two fins neighboring regions 21 and 22 here represent 50% of the length of the interval D40.

• pour numérateur, la superficie totale des ouvertures de débordement 40 situées dans une ailette 21 ou équivalent ayant des ouvertures de débordement 40, et
• pour dénominateur, la superficie totale d'une face 21.0 de cette ailette 21,

est ici égal à 20%.Each overflow opening 40 here has an area equal to 4 mm ² . An opening report having:

• for numerator, the total area of the overflow openings 40 located in a fin 21 or equivalent having overflow openings 40, and
• for denominator, the total area of a face 21.0 of this fin 21,

here is equal to 20%.

The figures 4 and 5 more particularly illustrate the operation of the dispensing device 1. The refrigerant F1 is shown in gray. As shown by figures 4 and 5 , the refrigerant F1 overflows with each overflow opening 40 and fills each distribution channel 42 of the fins 21, 22, 23, 24, 31, 32, 33 and 34.

1. i) par une ailette respective 222 ayant des ouvertures de débordement 240,
2. ii) par la plaque 11 solidarisée à la portion inférieure de cette ailette 222, et
3. iii) par l'ailette 221 située immédiatement en amont de l'ailette 222.

As shown by figures 4 and 5 , the volume of each distribution channel 42 (greyed out on the figure 4 or 5 ) is less than 10% of the total volume (in squares on the figure 4 ) delimited:

1. i) by a respective fin 222 having overflow openings 240,
2. ii) by the plate 11 secured to the lower portion of this fin 222, and
3. iii) by the fin 221 located immediately upstream of the fin 222.

• 1001) mettre en oeuvre le dispositif de distribution 1,
• 1002) canaliser du liquide frigorigène F1 dans les passages 20 et 30 et globalement suivant une direction longitudinale X,
• 1003) permettre l'écoulement du liquide frigorigène F1 par les orifices des ailettes 21 et équivalent ayant des orifices 40,
• 1004) emplir chaque canal de répartition 42 de sorte que du liquide frigorigène F1 s'écoule par les ouvertures de débordement 40 ; cette étape 1004) aboutit à l'état de fonctionnement illustré aux figures 4 et 5.

The figure 15 illustrates a dispensing method according to the invention for distributing the refrigerant F1 in the heat exchanger 2. This dispensing method comprises in particular the steps:

• 1001) implementing the dispensing device 1,
• 1002) channeling refrigerant F1 in the passages 20 and 30 and generally in a longitudinal direction X,
• 1003) allow the flow of the refrigerant F1 through the orifices of the fins 21 and equivalent having orifices 40,
• 1004) filling each distribution channel 42 so that refrigerant F1 flows through the overflow openings 40; this step 1004) results in the operating state illustrated in figures 4 and 5 .

Each distribution channel 42 is generally horizontal when the dispensing device 1 is in use. The cooperation of each distribution channel 42 with the overflow openings 40 makes it possible to distribute the refrigerant F1 as uniformly as possible along the lateral direction Y.

As shown in figure 3 , the heat exchanger 2 comprises a heat exchange unit, partially visible with the reference 4 to the figure 3 . In addition, the heat exchanger 2 comprises a heat transfer fluid inlet F 2 and an inlet 8 of refrigerant F1. The inlet 8 is here formed by perforations of a perforated bar 9.

The heat exchanger 2 further comprises the dispensing device 1, which is arranged to supply the refrigerant unit F1 with the heat exchange unit 4. In this case, the heat exchanger 2 includes a retention tank 3, wherein the refrigerant F1 is stored, before flowing to the dispensing device 1. In use, the dispensing device 1 is traversed by the refrigerant F1.

Second and third embodiments of the invention have in common that the total area of all overflow openings 140, 240, 241 for a given fin 121, 122, 123, 124 increases from top to bottom. This can be accomplished by increasing the number and / or area of openings.

The Figures 6 and 7 illustrate a portion of a dispensing device 101 according to the second embodiment of the invention. Insofar as the dispensing device 101 is similar to the dispensing device 1, the description of the dispensing device 1 given above in relation to the Figures 1 to 5 may be transposed to the distribution device 101, with the exception of the notable differences set out below.

A component of the distribution device 101 which is identical or corresponding, in structure or function, to a distribution device component 1 carries the same numerical reference increased by 100. Thus, plates 111, 112, fins 121, 122, are defined. 123, 124, overflow openings 140 and distribution channels 142.

The dispensing device 101 differs from the dispensing device 1 because the overflow openings 140 have elliptical shapes. On the other hand, as in the dispensing device 101, each orifice of each fin 121, 122, 123, 124 forms an overflow opening 140.

The fins 121, 123 have the same number of overflow openings but the areas of the openings 140 of the fin 123, lower are smaller than those of the openings 140 of the fin 123 above. The openings 140 of the fin 121 are fewer but have the same shape as that of the fin 122 below. This is also the case for the apertures of the fins 123 and 124. The total area of the openings increases in the direction going from upstream to downstream (downward direction on the figure 7 ) therefore downwards during the operation of the exchanger.

The Figures 8 and 9 illustrate a part of a dispensing device 201 according to a third embodiment of the invention. Insofar as the distribution device 201 is similar to the dispensing device 101, the description of the dispensing device 101 given above in relation to the Figures 6 and 7 can be transposed to the distribution device 201, with the exception of the notable differences set out below.

A component of the dispensing device 201 which is identical or corresponding, in structure or function, to a distribution device component 101 has the same numerical reference increased by 100. Thus, plates 211, 212 and fins 221, 222 are defined. 223, 224, overflow openings 240 and distribution channels 242.

The dispensing device 201 differs from the dispensing device 101, since two fins 221 and 222 have orifices 241 which do not form overflow openings 240. Only the fins 223 and 224 have overflow openings 240. In fact, the orifices 221 and 222 have openings 241 which do not form overflow openings 240. 241 are few on the fins 221 and 222, so that the orifices 241 are rather embedded when the dispensing device 201 is in use.

The fins 221 and 222 are placed upstream of the fins 223 and 224 having overflow openings 240. The orifices 241 are distributed in the lateral direction. The number of overflow openings 240 per fin 223 or 224 is greater than 5 times the number of orifices 241 per fin 221 or 222.

The number of orifices 241 per fin 221 or 222 increases in the direction going from upstream to downstream (downward direction on the figure 9 ) therefore downwards during the operation of the exchanger. The interval D241.1 between two successive orifices 241, measured along the lateral direction of the fin 221 having the orifices 241 situated furthest upstream (above the figure 9 ) is here equal to 51 mm. In fact, the gap 11-12 between the plates 11 and 12 is approximately equal to 51 mm. The interval D241.2 between two successive orifices 241, measured along the lateral direction, of the fin 222 having the orifices 241 located the most downstream is here equal to 20 mm.

Unlike the dispensing device 1, when the dispensing device 201 is in use, the fins 221 and 222 having orifices 241 can fulfill a function of controlling the flow rate of the refrigerant entering the dispensing device 201, generating a high pressure drop, while the fins 223 and 224 having overflow openings 240 rather perform a distribution function, generating only a small pressure drop.

The figure 10 illustrates a portion of a dispensing device 301 according to a third embodiment of the invention. Insofar as the dispensing device 301 is similar to the dispensing device 1, the description of the dispensing device 301 given above in relation to the Figures 1 to 5 can be transposed to the dispensing device 301, with the exception of the notable differences set out below.

A component of the dispensing device 301 that is identical or corresponding, in structure or function, to a dispensing device component 1 has the same numerical reference increased by 300. Thus, plates 311, 312, a passage 320 and fins are defined. 321, 322, 323, 324.

The dispensing device 301 differs from the dispensing device 101, since the fins 321, 322, 323, 324 and the plates 311 and 312 are disposed in an area of the dispensing device 301 where the passage 320 is relatively wide, since this zone is without ducts circulating fluid F2. Indeed, each duct of circulating fluid F2 is obstructed by a shutter 350 and the unrepresented outlet of the heat-exchange fluid ducts F2 is on a lateral face of the dispensing device 301.

Thus, at the fins 321, 322, 323, 324, the passages 320 can be deployed over the entire height, measured in the Z direction, of the dispensing device 301, while the passages 20 and 30 alternate with respective fluid conduits. calorigen F2. For example, the gap 311.312 between the plates 311 and 312 is approximately equal to 110 mm, while the gap 11-12 between the plates 11 and 12 is approximately equal to 51 mm.

Thus, the fastening portion of each fin 321, 322, 323, 324 is relatively small, which reduces the stresses on solder fades formed between the plate and the fin.

Furthermore, the fins 321, 322, 323, 324 may have orifices and overflow openings configured as the first embodiment ( Figures 1 to 5 number of constant overflow openings) or as the third embodiment ( Figures 8 and 9 : gradual increase in the number of orifices).

• des ailettes 421 et 422 disposées dans une zone où l'écart entre plaques 411 et 412 est large (exemple : 110 mm),
• avec des ailettes 423, 424 et équivalent disposées dans une zone où le passage 420 est rétréci (exemple : 55 mm) en raison de la présence alternée des conduits de fluide calorigène F2.

The figure 11 illustrates a portion of a dispensing device 401 according to a fifth embodiment of the invention. The dispensing device 401 combines:

• fins 421 and 422 disposed in an area where the gap between plates 411 and 412 is wide (example: 110 mm),
• with fins 423, 424 and the like disposed in an area where the passage 420 is narrowed (eg 55 mm) due to the alternating presence of the circulating fluid conduits F2.

Each heat transfer fluid duct F2 is obstructed by a shutter 450 and the unrepresented outlet of the heat-exchange fluid ducts F2 is located on a lateral face of the dispensing device 301.

The fins 421, 422 disposed in the wide area of the passage 420 may have orifices but not overflow openings, while the fins 423, 424 disposed in the narrow zone of the passage 420 may have overflow openings.

The figure 11 illustrates a portion of a dispensing device 501 according to a sixth embodiment of the invention. The dispensing device 501 is similar to the dispensing device 1. The dispensing device 501 comprises plates 511, 512 and the like, a coolant inlet 508, fins 521 and the like, and a shutter 550 to block the circulating fluid conduits. F2.

The dispensing device 501 differs from the dispensing device 1 because the area where the holding tank 503 is disposed is wider than the area where the holding tank 3 is arranged, which makes it possible to increase the distance between the plates 511. and 512 and each orifice forming the inlet 508 of the refrigerant. Thus, it reduces or avoids the risk of partial or total closure of each of these orifices by capillarity of the solders. In addition, this wider zone makes it possible to define larger orifices for the flow of the refrigerant liquid.

Of course, the invention is not limited to the particular examples described and illustrated in the present application. Other variants or embodiments within the reach of those skilled in the art can also be envisaged without departing from the scope of the invention defined by the claims below.

Thus, alternatively to the embodiments described above, the fins may have profiles other than flat and oblique. For example, the figure 13 illustrates a portion of a dispensing device 601 whose fins are flat and composed of an oblique band and a lateral band which is horizontal when the dispensing device is in use. Similarly, figure 13 illustrates a portion of a dispensing device 601 whose fins are flat and sinusoidal.

Claims (14)

1. Heat exchanger (2) configured to transfer heat from at least one calorigenic fluid (F2), for example nitrogen, to at least one refrigerant fluid (F1), for example oxygen, the heat exchanger (2) comprising plates (3, 11, 12, 13, 14) arranged parallel to one another in such a way as to define a first series of passages (20, 30) configured to channel liquid refrigerant (F1) overall along a longitudinal direction (X), extending in the vertical direction during operation, each passage (20, 30) being defined between two successive plates (11, 12-13, 14), and a second series of passages configured to channel a calorigenic fluid overall along the longitudinal direction (X), each passage being defined between two successive plates, the passages of the second series being inserted between two passages of the first series, at least one inlet (8; 508) of liquid refrigerant (F1) configured to pour the liquid refrigerant only into the passages of the first series and a distribution device, located in the upper end of the exchanger in passages of the first series only, comprising fins (21, 22, 23, 24 - 31, 32, 33, 34) extending in one, even in each passage (20, 30) of the first series overall along a lateral direction (Y) which is orthogonal to the longitudinal direction (X) and which is parallel to the plates (11, 12, 13, 14), each passage (20, 30) of the first series housing several fins (21-24, 31-34) in succession along the longitudinal direction (X),
   characterised in that
   each fin (21-24, 31-34) has orifices configured to make it possible for the flow of the liquid refrigerant (F1);
   at least one fin (21, 22, 23, 24) having an upper portion (21.1) and one lower portion (21.2), the altitude of the upper portion (21.1) being greater than the altitude of the lower portion (21.2) when the distribution device (1) is in service and the longitudinal direction extends in the vertical direction,
   said at least one lower portion (21.2) and the plate (12) secured to said at least one lower portion (21.2) defining at least one distribution channel (42; 142; 242) configured to channel liquid refrigerant (F1) along the lateral direction (Y),
   the orifices of said at least one fin (21, 22, 23, 24) being formed by overflow openings (40; 140; 240) located in said at least one upper portion (21.1), the overflow openings (40) being configured such that the liquid refrigerant (F1) flows through the overflow openings (40) when said at least one distribution channel (42) is full of liquid refrigerant (F1).
2. Heat exchanger according to claim 1, wherein the volume of a respective distribution channel (42; 142; 242) is less than 15%, preferably less than 10%, of the total volume delimited by:

   i) a fin (22) having overflow openings (40),

   ii) the plate (11) secured to the lower portion of said fin (22) having overflow openings (40), and

   iii) the fin (21) located immediately upstream of said fin (21) having overflow openings (40).
3. Heat exchanger according to any one of the preceding claims, wherein the overflow openings (40) are distributed over a fin (21, 22, 23, 24) uniformly along the lateral direction (Y).
4. Heat exchanger according to any one of the preceding claims, wherein an opening ratio having:

   - as the numerator, the total surface area of the overflow openings (40; 140; 240) located in a fin (21, 22, 23, 24) having overflow openings, and

   - as the denominator, the total surface area of one face of said fin (21, 22, 23, 24) having overflow openings (40; 140; 240),

   is between 10% and 50%, preferably between 20% and 40%.
5. Heat exchanger according to any one of the preceding claims, wherein each overflow opening (40; 140; 240) has a surface area between 1.5mm² and 10.0mm², preferably between 2.0mm² and 5.0mm².
6. Heat exchanger according to any one of the preceding claims, wherein an interval (D40), measured along the lateral direction (Y), between two successive overflow openings (40) is between 1mm and 6mm.
7. Heat exchanger according to any one of the preceding claims, wherein a minimum distance (H40) between i) an overflow opening (40) and ii) the plate (12) secured to said at least one lower portion (21.2) is between 1mm and 4mm, the minimum distance (H40) being preferably the same for the majority or all of the overflow openings (40) of a respective fin (21, 22, 23, 24).
8. Heat exchanger according to any one of the preceding claims, wherein several fins (21, 22, 23, 24) have respective upper portions (21.1) having overflow openings (40).
9. Heat exchanger according to claim 8, wherein the overflow openings (40) present in a fin (21) are positioned offset (D40/2) along the lateral direction (Y) with respect to the overflow openings (40) present in the adjacent fin (22).
10. Heat exchanger according to claim 9, wherein said offset (D40/2) between the overflow openings (40) present in two adjacent fins (21, 22) represents between 40% and 60% of the length of said interval (D40).
11. Heat exchanger according to any one of the preceding claims, wherein at least one fin (21, 22, 23, 24) has a flat shape and extends to said two successive plates (11, 12, 13, 14) and obliquely to each one of said two successive plates (11, 12, 13, 14) so as to form, as a section in a plane perpendicular to the plates (11, 12, 13, 14) and to the lateral direction (Y), an acute oblique angle (A21), the oblique angle (A21) being preferably between 30° and 60°, more preferably between 40° and 50°.
12. Heat exchanger according to any one of the preceding claims, wherein each fin (21, 22, 23, 24) has, parallel to the longitudinal direction (X), a length (X21) between 4mm and 10mm, and wherein each fin (21, 22, 23, 24) has, parallel to the lateral direction (Y), a width (Y21) between 4mm and 10mm, each fin (21, 22, 23, 24) could, for example, have a length (X21) and a width (Y21) that are equal.
13. Heat exchanger according to any one of the preceding claims, comprising at least one fin (121, 122; 221, 222) having orifices (141; 241) and placed upstream of the fin(s) (123, 124; 223, 224) having overflow openings (140; 240), the orifices (141; 241) being distributed along the lateral direction (Y), the number of overflow openings (140; 240) per fin being 3 times, preferably 5 times, greater than the number of orifices (141; 241) per fin.
14. Heat exchanger (2), according to one of the preceding claims, wherein the total surface area of the openings (40, 140, 240, 241), or even of the overflow openings (140, 240), for a given fin (121, 122, 123, 124) increases in the longitudinal direction (X), preferably by increasing the number and/or the surface area of the openings.

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