Heat Exchanger Plate with Fluid Flow Disrupting Elements

The present invention relates to the field of heat exchangers, and more particularly those heat exchangers that are equipped with fluid-flow-disturbing elements.

These heat exchangers can for example equip a vehicle. They are then arranged within this vehicle to allow the thermal regulation of a first fluid circulating in a first space by virtue of the circulation of a second fluid in a second space separate from the first space, such that the two fluids do not mix. The fluids can notably be a refrigerant fluid circulating within an air-conditioning loop of the vehicle or a cooling liquid intended to regulate the temperature of a combustion engine.

Within the heat exchangers and thermodynamic circuits to which they are connected, the fluids circulate while dissipating or absorbing thermal energy. The effectiveness of the heat exchangers and of the thermodynamic circuits is mainly determined by the exchanges of heat between the fluids that flow through them. It is therefore sought to design heat exchangers in which the exchanges of heat between the fluids that circulate within them are optimized. To this end, it is known to equip the heat exchangers with fluid-flow-disturbing devices, so as to increase the exchanges of heat between the fluids.

One type of heat exchanger used in the field of cars is a plate exchanger, made up of a stack of plates secured to one another by brazing, in which stack the spaces remaining between two contiguous plates after brazing define fluid circulation zones. These circulation zones are normally adapted to the fluids that flow through them, thereby implying the existence of several different types of plates. A technical problem is that the means for producing and storing these plates are different, and this makes the logistical management during the manufacture of these plate heat exchangers more complex.

The present invention aims to overcome this drawback by proposing a heat exchanger plate of which the fluid-flow-disturbing devices are configured to optimize the fluid circulation disturbance for the one part, while at the same time offering improved mechanical strength within the heat exchanger that is equipped with the plate, the dimensioning of these plates being configured such that the plate adapts, notably by deformation, to the height of the fluid circulation space, which is notably defined by the disturbance devices.

The main subject of the present invention is therefore a plate of a heat exchanger having a tub-like form with two opposite longitudinal edges connected to one another by two lateral edges, these longitudinal edges and lateral edges surrounding a bottom wall of the plate, an angle measured between this bottom wall and any one of the edges ranging between 103.5° and 109.5°, a thickness of the bottom wall ranging between 0.20 mm and 0.45 mm, the bottom wall being equipped with fluid-flow-disturbing elements, at least one of these fluid-flow-disturbing elements having a vertical dimension measured inside a volume delimited by the bottom wall and the edges that ranges between 0.75 mm and 1.15 mm.

The heat exchanger plate according to the invention is configured for the circulation of fluid, such circulation making it possible to optimize the exchanges of heat via the fluid-flow-disturbing elements. The fluid-flow-disturbing elements are deformations of the bottom wall. The fluid circulates within a volume of the heat exchanger plate that is delimited both by a bottom wall, from which the fluid-flow-disturbing elements project, and by longitudinal and lateral edges which extend in planes intersecting the bottom wall. These intersecting planes are not necessarily perpendicular to the bottom wall, and this gives the heat exchanger plate its tub-like form.

More particularly, an angle measured between the bottom wall and any one of the edges, which is to say either a longitudinal edge or a lateral edge, ranges between 103.5° and 109.5°; preferably, this angle ranges between 105° and 108°; more preferentially still, this angle ranges between 105.5° and 107.5°.

The bottom wall has a determined thickness, this thickness corresponding to its vertical dimension measured between a first face of the plate and a second face of the plate. Such a dimension is measured along a vertical direction which extends perpendicularly to a plane in which the bottom wall mainly extends. Preferentially, the thickness of the plate ranges between 0.20 mm and 0.45 mm, and it ideally ranges between 0.27 mm and 0.35 mm.

A vertical dimension of the fluid-flow-disturbing elements, which corresponds to their size measured in the vertical direction, is also predetermined. It thus ranges between 0.75 mm and 1.15 mm. It will be understood that the fluid-flow-disturbing elements project from a plane in which the bottom wall extends and extend into a space delimited between the longitudinal and lateral edges, which is to say into the volume of the heat exchanger plate.

According to one feature of the invention, the vertical dimension of the fluid-flow-disturbing elements is a first vertical dimension ranging between 0.75 mm and 0.85 mm.

According to another feature of the invention, the vertical dimension of the fluid-flow-disturbing elements is a second vertical dimension ranging between 1.05 mm and 1.15 mm.

Thus, the fluid-flow-disturbing elements can have either a first vertical dimension, ranging between 0.75 and 0.85 mm, or a second vertical dimension, ranging between 1.05 and 1.15 mm; it will be understood that these two separate vertical dimensions, which correspond to the heights of the fluid-flow-disturbing elements, relate to two possible embodiments of the heat exchanger plate.

According to one feature, the bottom wall is equipped with at least four fluid distribution openings, each of these fluid distribution openings being disposed in the vicinity of a junction between a longitudinal edge and a lateral edge.

The role of these fluid distribution openings is to convey or discharge the fluid to/from the volume of the heat exchanger plate. These fluid distribution openings are disposed on the plate such that there is a fluid distribution opening at each corner of this plate.

According to one feature of the invention, the fluid-flow-disturbing elements comprise at least one truncated dome extending between a base and a top.

Such a truncated-dome shape is defined in a sectional view, which in this case corresponds to a vertical section plane. These truncated domes extend between a base and a top, their base corresponding to their portion which is joined to the bottom wall whereas their top is the portion farthest away from this plane, the top forming a free end of the truncated dome, before the heat exchanger is brazed. The top of the truncated dome is a flat part, extending preferably parallel to the bottom wall.

The fluid-flow-disturbing elements are deformations, for example made by stamping, of the bottom wall. The mechanical strength of the heat exchanger plate notably depends on the thinning of material obtained during the deformation of the bottom wall to obtain these fluid-flow-disturbing elements.

According to one feature, a maximum diameter of the truncated dome measured at its base is 4.5 mm.

According to another feature of the invention, a minimum diameter of the truncated dome measured at its top is 2 mm.

It will be understood here that the base of the truncated domes, which is to say their bottom, is circular and potentially has a greater diameter than their top, which is also circular.

According to one feature, the bottom wall is equipped with a separating strip which extends from one of the lateral edges toward the other lateral edge, without however being in contact with the latter.

According to one feature, the separating strip has a sinusoidal shape.

Like the fluid-flow-disturbing elements, the effect of the separating strip is to optimize the exchanges of heat within the heat exchanger plate by lengthening the path taken by the fluid in the volume of this plate.

The invention moreover relates to, according to a first embodiment, a heat exchanger configured to bring about an exchange of heat between a first fluid and a second fluid, this heat exchanger comprising first plates as set out above, which is to say having the first vertical dimension, and second plates as set out above, which is to say having the second vertical dimension.

According to one of the aspects of the invention, the first and second fluids that bring about an exchange of heat can respectively be a heat-transfer fluid, of the dielectric type, a cooling fluid such as water or a mixture of water and ethylene glycol, or a refrigerant fluid, such as R134a, R1234yf or R744.

The first plates and second plates then make up a heating body within the heat exchanger, this heating body corresponding to its portion where the fluids circulate and therefore where the exchanges of heat take place. Within the heat exchanger according to this first embodiment, a first fluid and a different second fluid circulate respectively between two adjacent plates, for example so as to have the first-fluid circulation zone and the second-fluid circulation zone alternate, these circulation zones being vertically delimited by the bottom walls of the adjacent plates. Such a heat exchanger in this case has first plates of which the height of the fluid-flow-disturbing elements ranges between 0.75 and 0.85 mm, and second plates of which the height of the fluid-flow-disturbing elements ranges between 1.05 and 1.15 mm, installed alternately. Within one and the same heat exchanger, spaces between the plates that make it up therefore have varying vertical dimensions. Such a combination of first and second plates provides the heat exchanger with dimensional flexibility as regards its circulation zones. It is thus possible, by way of example, to obtain a first-fluid circulation zone larger than a second-fluid circulation zone, or vice versa.

According to this first embodiment, the angle measured between the bottom wall and any one of the edges ranges between 105° and 108°. Preferentially, this angle ranges between 105.5° and 107.5°. Such an angle provides a flexibility which makes it possible to deform the edge of the plates having the first vertical dimension or the second vertical dimension, while still ensuring the leaktightness between these plates at least at their edge.

As an alternative and according to a second embodiment, the invention relates to a heat exchanger configured to bring about an exchange of heat between a first fluid and a second fluid, this heat exchanger comprising a heating body solely made up of plates as set out above, which is to say having the first vertical dimension.

In this case, the heat exchanger has a heating body, which is to say a portion dedicated to the exchanges of heat, made up exclusively of first plates, which is to say plates of which the fluid-flow-disturbing elements have a vertical dimension ranging between 0.75 and 0.85 mm.

According to this second embodiment, the angle measured between the bottom wall and any one of the edges ranges between 106.5° and 109.5°. This angle is particularly suitable for ensuring the stacking of the plates having the first vertical dimension, and also the leaktightness between two plates, at least at their edges.

According to a third embodiment, the invention is understood to cover a heat exchanger configured to bring about an exchange of heat between a first fluid and a second fluid, this heat exchanger comprising a heating body solely made up of plates as set out above, which is to say having the second vertical dimension.

In this case, the heat exchanger has a heating body, which is to say a portion dedicated to the exchanges of heat, made up exclusively of second plates, which is to say plates of which the fluid-flow-disturbing elements have a vertical dimension ranging between 1.05 and 1.15 mm.

According to this third embodiment, the angle measured between the bottom wall and any one of the edges ranges between 103.5° and 106.5°. This angle is particularly suitable for ensuring the stacking of the plates having the second vertical dimension, and also the leaktightness between two plates, at least at their edges.

According to another feature, the plates are assembled by brazing.

The brazing notably ensures the leaktightness of the heat exchanger, since the first fluid and the second fluid thus have separate circulation zones which are not in communication, these zones furthermore being leaktight with respect to the external environment of the heat exchanger.

According to one feature, the plates are stacked in a stacking direction, the fluid-flow-disturbing elements of two plates that are adjacent in the stacking direction being disposed in staggered fashion.

The stacking direction corresponds to the vertical direction; it is the direction in which the plates are superposed with one another such that their respective longitudinal and lateral edges are in contact. “Disposed in staggered fashion” is understood in this case to mean that the fluid-flow-disturbing elements of a given plate are not vertically aligned with the fluid-flow-disturbing elements of the one or more plates that are adjacent to it, notably when these plates are viewed in a vertical section passing through three fluid-flow-disturbing elements. In other words, the fluid-flow-disturbing elements of a plate do not overlap the fluid-flow-disturbing elements of the adjacent plate when these plates are viewed from above.

According to another feature, the tops of the fluid-flow-disturbing elements of a plate are in contact with the bottom wall of the plate that is adjacent to it in the stacking direction.

The fluid-flow-disturbing elements are thus points of contact between two adjacent plates. Such a connection moreover contributes to delimiting a circulation pathway for the fluid within the circulation zone of the heat exchanger plate, and therefore disturbs the flow of this fluid in the volume of the plate. Furthermore, the contact between the fluid-flow-disturbing elements of a first plate and the bottom wall of a plate superposed with it contributes to the mechanical reinforcement of the heat exchanger, serving to secure the two plates and allowing a distribution of the forces among all of the contact points formed by the fluid-flow-disturbing elements.

The features, variants and different embodiments of the invention can be combined with one another in various combinations, provided that they are not mutually incompatible or exclusive. It will be possible, in particular, to imagine variants of the invention that comprise only a selection of the features described below, in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage and/or to distinguish the invention from the prior art.

In the figures, elements that are common to several figures have the same reference.

In the following detailed description, the terms “longitudinal”, “transverse” and “vertical” refer to the orientation of the heat exchanger plate according to the invention. A longitudinal direction corresponds to a main direction of extent of this plate, this longitudinal direction being parallel to a longitudinal axis L of a coordinate system L, V, T illustrated in the figures. A vertical direction corresponds to a direction measured in line with a plane in which the bottom wall of the heat exchanger plate mainly extends, this vertical direction being parallel to a vertical axis V of the coordinate system L, V, T, and this vertical axis V being perpendicular to the longitudinal axis L. Lastly, a transverse direction corresponds to a direction parallel to a transverse axis T of the coordinate system L, V, T, this transverse axis T being perpendicular to the longitudinal axis L and to the vertical axis V.

thus illustrate a heat exchangeraccording to the invention, this heat exchangerbeing intended to equip a motor vehicle.is a perspective view, whereasis a view in section along the section A-A in. The heat exchangercontributes to the heating or cooling of at least one element of the motor vehicle that it equips. To that end, it is configured to bring about an exchange of heat, which is to say an exchange of heat energy, between a first fluid and a second fluid, both of which flow through it. This other fluid can for example be a heat-transfer liquid such as glycol water or oil.

The heat exchangerextends mainly in a longitudinal direction L. It comprises a plurality of plateswhich extend primarily in a plane including the longitudinal direction L and the transverse direction T. More particularly, the heat exchangeris formed by a stack of plates, which are superposed with one another in a stacking direction E, which is perpendicular to a plane in which the longitudinal direction L is inscribed and which corresponds to a vertical direction V.

Asparticularly shows, the stack of platesis covered by a cover plate, which constitutes an end plate of the heat exchanger. This cover plateis not shown in. It has a rectangular shape and its surface is smooth. Apart from the cover plateand a possible other cover plate situated opposite it in the stacking direction E, the set of platesmakes up a heating body of the heat exchanger, which is to say a portion within which the exchanges of heat between the first fluid and the second fluid take place.

As shown in, the heat exchangercomprises two connecting pipes,at a first one of its longitudinal ends and a connection blockat a second one of its longitudinal ends. These connecting pipes and connection block,,make it possible to convey fluids to the fluid distribution openings of the heat exchangerand to discharge them through these fluid distribution openings.

Two of the platesof the heat exchangeraccording to the invention are shown separately in, in a perspective view. These two platesare adjacent and superposed in the stacking direction E, one of the plateshaving been pivoted by a half-turn relative to the other. The stacking of the plateswithin the heat exchangeris such that the first fluid circulates between two directly adjacent plates, the second fluid for its part circulating between each of these two platesand other plates that are directly adjacent to them. Each plateof the heat exchangeris intended to be joined to the platesadjacent to it in the stacking direction E and/or to the cover plateby brazing, in order to ensure the leaktightness of the heat exchanger.

One of the platesof the heat exchangerwill now be described in more detail, the features of this platebeing applicable to each of the platesforming the heating body of the heat exchanger.

The platehas a substantially rectangular shape and four rounded corners. The plateis delimited by two oppositely situated longitudinal edges,extending in the longitudinal direction L, and two oppositely situated lateral edges,perpendicular to these longitudinal edges,. One of the lateral edges,is thus disposed at a first longitudinal endof the plate, the other of these lateral edges,being disposed at a second longitudinal endthereof. It will be understood here that the longitudinal edges,and lateral edges,make up a raised edge or perimeter of the plate.