Patent Description:
These heat exchangers may be used in vehicles in order to cool inlet gases of a turbocharged internal combustion engine with a coolant liquid, for instance a water-based coolant liquid.

Such heat exchangers usually comprise a casing inside which there are channels dedicated to the circulation of the gases as well as passes for the coolant liquid to circulate inside the heat exchanger. The channels and the passes are arranged so that the gases and the coolant liquid can exchange calories, resulting in a drop of temperature for the gases.

More specifically, the channels can extend from one end of the heat exchanger bearing an air inlet to another end bearing an air outlet, the air circulating inside the heat exchanger from the air inlet to the air outlet. The channels are usually stacked horizontally, i.e. one next to the other in a direction perpendicular to that of the air flow. The liquid coolant can circulate in passes located in between the channels, from a liquid inlet to a liquid outlet. Due to this disposition of the liquid inlet and outlet relative to that of the passes, there can however be a risk of local boiling in the vicinity of the liquid outlet for the passes which are the farthest from the centre of the heat exchanger. These passes are indeed at risk of not being cooled enough by the coolant liquid. As such, there is a need for heat exchangers inside of which the coolant liquid flow is improved.

The present invention fits into this context by providing a heat exchanger with a liquid chamber designed to improve the flow of the coolant liquid, thus allowing to avoid local boiling in the passes located at a distance from the centre of the heat exchanger.

In this context, the present invention is directed to a heat exchanger configured to cool an air flow with a coolant liquid, comprising a heat core, a first air flow duct located at a first longitudinal end of said heat core and a second air flow duct located at a second longitudinal end of said heat core, the heat core comprising a plurality of air flow channels defining liquid passes in between at least two air flow channels, said heat core comprising a group of central liquid passes and two lateral liquid passes bordering said group of central liquid passes, said heat core comprising a plurality of plates enveloping the air flow channels and the liquid passes, at least one of the plates having a plane portion and a projection defining a liquid chamber which is in liquid communication with the liquid passes, the liquid chamber having a first section covering at least one of the lateral liquid passes which is bigger than a second section covering at least one of the central liquid passes.

The heat exchanger according to the invention requires a coolant liquid in order to cool the air. This air flows in the heat exchanger, and more precisely in its heat core, from the first air duct or air inlet located at its first longitudinal end, to the second air duct or air outlet located at its second longitudinal end which is opposed to the first longitudinal end.

The plurality of plates of the heat core, for instance four plates, define an internal housing for the air and the coolant liquid to circulate inside the heat core. More precisely, when circulating inside the heat core the air is contained in air flow channels whereas the coolant liquid can circulate in the spaces between these air flow channels, which form liquid passes. Two of the plates are used to delimit the liquid passes vertically, by closing a volume inside of which the coolant liquid can circulate. One of these two plates bears the projection defining the liquid chamber, wherein the coolant liquid can circulate as well. The projection of the plate making up the liquid chamber extends opposite of the internal housing.

The liquid may be a water-based coolant liquid, e.g., a mix of water and glycol, which is designed to exchange calories with the air flowing inside the air flow channels. Each air flow channel is furthermore equipped with an air flow disrupter, which helps distribute the air inside the heat core.

The first section and second section of the liquid chamber are measured according to the direction in which the air flow channels mainly extend, which is a longitudinal direction from the first longitudinal end to the second longitudinal end or conversely. The first section is bigger than the second section, i.e. its dimension measured according to the longitudinal direction is greater than that of the second section. Such disposition of the liquid chamber helps improve the coolant liquid flow in the lateral liquid passes, thus preventing local boiling in these lateral liquid passes.

The projection comprises at least one front side and at least one back side opposite to the front side. The liquid chamber is located closer to one of the longitudinal end of the heat core. The front side of this projection is closer to this particular end of the heat core, whereas the back side faces the opposite longitudinal end. For instance, if the liquid chamber is located closer to the air outlet than to the air inlet, the front side will face the longitudinal end of the heat core bearing the air outlet while the back side will be facing towards the air inlet.

As an option of the invention, the front side is straight and the back side comprises at least a curved part.

These sides extend mainly perpendicularly to the longitudinal direction of the heat core. According to another option, the back side has a convex shape when seen from the opposite front side.

Alternatively, the back side has a W-shape when seen from the opposite front side.

The convex shape corresponds to a first embodiment of the liquid chamber, whereas the W-shape is a second embodiment. This W-shape includes an increased section of the liquid chamber covering the most central liquid pass among the plurality of central liquid passes.

According to an optional characteristic of the invention, the back side is continuous from one lateral liquid pass to the other lateral liquid pass.

According to an optional characteristic, the front side and the back side are joined by two lateral sides, these two sides extending mainly parallel to the air flow channels.

Each of the lateral sides thus extends alongside a transverse end of the plate having the liquid chamber, these transverse ends also extending parallel to the air flow channels. The two lateral sides may consequently be perpendicular or substantially perpendicular to the front side.

In some embodiments, a section of one of the lateral sides is longer than a section of the other lateral side, such sections being measured according to a longitudinal direction of the heat core parallel to the air flow channels.

Such discrepancy is the dimension of the aforementioned sections results in a dissymmetry of the lateral sides of the liquid chamber, which allows a modulation of the coolant liquid flow.

According to another optional characteristic, the heat core comprises at least a coolant inlet and a coolant outlet, the projection defining the liquid chamber bearing one of them.

The coolant liquid enters the heat core via the coolant inlet and exits it via the coolant outlet. Either the coolant inlet or the coolant outlet is located on the projection. In other words, either the coolant inlet is located on the liquid chamber or the coolant outlet is located on the liquid chamber.

In particular embodiments, there can be two projections for two liquid chambers, one bearing the coolant inlet and the other bearing the coolant outlet.

According to another optional characteristic of the invention, the coolant inlet and the coolant outlet are located on opposite plates of the heat core.

Such arrangement of the coolant inlet and outlet ensures a satisfactory flow of coolant in the heat core, so that all the air flow channels are adequately cooled.

According to another optional characteristic of the invention, the coolant outlet is located closer to the first longitudinal end of the heat core whereas the coolant inlet is located closer to the second longitudinal end of the heat core.

Likewise, this arrangement of the coolant inlet and of the coolant outlet contributes to a satisfactory distribution of coolant liquid in the heat core.

Other characteristics, details and advantages of the invention will become clearer on reading the following description, on the one hand, and several examples of realisation given as an indication and without limitation with reference to the schematic drawings annexed, on the other hand, on which:.

The characteristics, variants and different modes of realization of the invention may be associated with each other in various combinations, in so far as they are not incompatible or exclusive with each other. In particular, variants of the invention comprising only a selection of features subsequently described in from the other features described may be imagined, if this selection of features is enough to confer a technical advantage and/or to differentiate the invention from prior art.

Like numbers refer to like elements throughout drawings.

In the following description, the designations "longitudinal", "transversal" and "vertical" refer to the orientation of the heat exchanger according to the invention. A longitudinal direction corresponds to a direction in which the air flow channels of the heat exchanger mainly extend, this longitudinal direction being parallel to a longitudinal axis L of a coordinate system L, V, T shown in the figures. A transversal direction corresponds to a direction in which the liquid passes slot in between the air flow channels, this transversal direction being parallel to a transverse axis T of the coordinate system L, V, T, and perpendicular to the longitudinal axis L. Finally, a vertical direction corresponds to a vertical axis V of the coordinate system L, V, T, the vertical axis V being perpendicular to the longitudinal axis L and the transversal axis T.

<FIG> are perspective views of a heat exchanger <NUM> according to the invention, such heat exchanger <NUM> being destined to cool an air flow. The heat exchanger <NUM> can for example be installed in a vehicle such as an automobile vehicle in order to cool its inlet gases.

The heat exchanger <NUM> comprises a heat core <NUM>, which makes up its central portion. The heat core <NUM> is furthermore the part of the heat exchanger <NUM> where calorie exchanges occur, these calorie exchanges being essential to the cooling of the air flow. To this end, the heat core <NUM> comprises air flow channels <NUM> within which the air needing to be cooled can circulate. Such air flow channels <NUM> are particularly visible on <FIG>, as well as on <FIG> which is a cross-section view. These air flow channels <NUM> extend from one side of the heat core <NUM> to the other according to a longitudinal direction, more particularly from a first longitudinal end <NUM> of the heat core to its second longitudinal end <NUM>. The air flow channels <NUM> are contained in an internal housing <NUM> of the heat core <NUM>, which is made of plates such as aluminium plates. As represented here, the heat core <NUM> comprises four rectangular plates, among which a first plate <NUM>, a second plate <NUM>, a third plate <NUM> and a fourth plate <NUM>. The first plate <NUM> and the third plate <NUM> face each other and extend mainly according to a longitudinal-transversal plane, whereas the second plate <NUM> and the fourth plate <NUM> face each other and extend mainly according to a longitudinal-vertical plane.

The air flow thus circulates in the internal housing <NUM> and more precisely in the air flow channels <NUM> from the second longitudinal end <NUM> to its first longitudinal end <NUM>. More specifically, the air flow may enter the heat exchanger <NUM> via an air inlet <NUM> located at the second longitudinal end <NUM> and may exit it via an air outlet <NUM> located at the first longitudinal end <NUM> of the heat core <NUM>. Both the air inlet <NUM> and the air outlet <NUM> are air flow ducts, and they may for instance be made of polyvinyl chloride.

Each air flow channel <NUM> is equipped with an air flow disrupter <NUM>, which helps distribute the air flow more homogeneously within the heat core <NUM>. These air flow disrupters are particularly visible on <FIG>. They snake inside their respective air flow channels <NUM> from one of their lateral ends in the vicinity of the first plate <NUM> to an opposite lateral end of the air flow channels <NUM> close to the third plate <NUM>, forming winglets in the air flow channels <NUM> so as to deviate the air flowing inside them.

The air flow channels <NUM> are stacked one next to the other according to a transverse direction, perpendicular to the longitudinal direction. The spaces between two contiguous air flow channels <NUM> define liquid passes <NUM>, within which a coolant liquid may circulate. This coolant liquid can be water-based; it can for instance be a mix of <NUM> % water and <NUM> % glycol. In addition to the liquid passes <NUM>, the coolant liquid may also circulate in the spaces between the air flow channels <NUM> and the first plate <NUM> on the one hand and between these air flow channels <NUM> and the third plate <NUM>. Among the liquid passes <NUM>, the heat core <NUM> comprises a group of central liquid passes <NUM> as well as two lateral liquid passes <NUM>, <NUM> bordering said group of central liquid passes <NUM>, among which a first lateral liquid pass <NUM> and a second lateral liquid pass <NUM>. The first lateral liquid pass <NUM> faces the second plate <NUM> whereas the second lateral liquid pass <NUM> faces the fourth plate <NUM>, although there may be an air flow channel <NUM> in between each of these first and second lateral liquid passes <NUM>, <NUM> and the plate <NUM>, <NUM> they respectively face. In any case, every air flow channel <NUM> and every liquid pass <NUM> is contained within the internal housing <NUM> of the heat core <NUM> of the heat exchanger <NUM>. In other words, this internal housing <NUM> participates in delimiting a volume for both the air flow and the coolant liquid to circulate inside of.

The heat exchanger <NUM> according to the invention is configured to receive the coolant liquid via a coolant inlet <NUM> and to evacuate the coolant liquid via a coolant outlet <NUM>. Similarly to the air inlet <NUM> and the air outlet <NUM>, the coolant inlet <NUM> and the coolant outlet <NUM> are ducts and can be made of polyvinyl chloride. As shown on <FIG>, the coolant inlet <NUM> and the coolant outlet <NUM> may be located on opposite plates of the heat core <NUM>, with here the coolant outlet <NUM> located on the first plate <NUM> and the coolant inlet <NUM> located on the third plate <NUM>. This ensures the coolant liquid can flow through the heat core <NUM> from the first plate <NUM> to the third plate <NUM>, which means from one of its lateral end to the other, and cool the air flowing in the air flow channels <NUM> adequately. To this end, the coolant outlet <NUM> may in addition be located in the vicinity of the first longitudinal end <NUM> of the heat core <NUM> while the coolant inlet <NUM> is closer to its second longitudinal end <NUM>, thus reinforcing the spreading of the coolant liquid within the heat core <NUM>.

The first, second, third and fourth plates <NUM>, <NUM>, <NUM>, <NUM> making up the heat core <NUM> are mostly plane. However, according to the invention at least one of these plates, here the first plate <NUM>, has a projection in addition to its plane portion. Such projection defines a liquid chamber <NUM> which is in liquid communication with the liquid passes <NUM>, so that the coolant liquid can circulate through it. This liquid chamber <NUM> is particularly visible on <FIG> and <FIG>. The height H of the projection, which corresponds to its dimension measured according to the vertical direction, can for example be of the order of <NUM>,<NUM>. The liquid chamber is made of four sides <NUM>, <NUM>, <NUM>, <NUM> extending from the first plate <NUM> and opposite to the internal housing <NUM>. These four sides <NUM>, <NUM>, <NUM>, <NUM> are joined by a back wall <NUM>, which is pierced with a hole <NUM> to which either the coolant inlet <NUM> or the coolant outlet <NUM> can be connected. The back wall <NUM> is mainly parallel to the plane portion of the first plate <NUM>.

Out of these four sides, two delimit the liquid chamber <NUM> according to the transverse direction, namely a first lateral side <NUM> and a second lateral side <NUM> which are particularly visible on <FIG>. These lateral sides <NUM>, <NUM> extend along the longitudinal direction, that is to say mainly parallel to the air flow channels <NUM> and to the liquid passes <NUM>.

In some particular embodiments, not shown on the figures, either the first lateral side <NUM> is longer than the second lateral side <NUM> or conversely the second lateral side <NUM> is longer than the first lateral side <NUM>. More precisely, a section of one of these lateral sides <NUM>, <NUM> is longer than the other, such section being measured according to the longitudinal direction. The resulting shape of the liquid chamber <NUM> allows a different repartition of the cooling liquid within the heat core <NUM>, thus enabling an increase of the cooling phenomenon on one side of the heat core <NUM> and more particularly for a chosen lateral liquid pass <NUM>, <NUM>.

The first and second lateral sides <NUM>, <NUM> are joined by at least one front side <NUM>, which faces the first longitudinal end <NUM> of the heat core <NUM>, and at least one back side <NUM> opposite the front side <NUM>. The front side <NUM> and the back side <NUM> forming the projection of the liquid chamber <NUM> may exhibit varying shapes depending on the embodiments. As shown on the figures, the front side <NUM> is straight and extends mainly perpendicularly to the longitudinal direction of the heat core <NUM>, along the first longitudinal end <NUM>, whereas the back side <NUM> is curved. According to the invention, the liquid chamber <NUM> thus has a first section <NUM> covering at least one of the lateral liquid passes <NUM>, <NUM> which is bigger than a second section <NUM> covering at least one of the central liquid passes <NUM>. This first section <NUM> and second section <NUM> are measured according to the longitudinal direction, and it is understood that by "bigger" it is meant that the first section <NUM> has a greater dimension than the second section <NUM> when they are measured according to this longitudinal direction. Such first section <NUM> and second section <NUM> can be seen on <FIG> and <FIG>. As an example, the first section can be about <NUM> long whereas the second section <NUM> can be about <NUM> long.

There can be a third section <NUM>, covering the lateral liquid pass <NUM>, <NUM> which is not covered by the first section <NUM>. For instance, the first section <NUM> may cover the first lateral liquid pass <NUM> while the third section covers the second lateral liquid pass <NUM>, the second section <NUM> covering any or a plurality of the central liquid passes <NUM>. Such shape of the liquid chamber <NUM> ensures that the coolant liquid is distributed adequately within the heat core <NUM>, and particularly in direction of the lateral liquid passes <NUM>, <NUM> which may be subject to local boiling if they are not sufficiently cooled.

The back side <NUM> is continuous from the first lateral side <NUM> to the second lateral side <NUM>, as well as from the first lateral liquid pass <NUM> to the second lateral liquid pass <NUM>. It may have a convex shape when seen from the front side <NUM>. Alternatively and although not illustrated on the figures, the back side <NUM> may have a W-shape when seen from this front side <NUM>. Both embodiments help improve the flow of coolant liquid within the heat core <NUM>. When the back side <NUM> is of the W-shape, one section covering the central liquid pass <NUM> located in the middle of the heat core <NUM> according to the transverse direction has an increased dimension compared to that of the second section <NUM>. In other terms, this particular section covering the central liquid pass <NUM> located in the middle may have the same dimension than that of the first section <NUM> or the second section <NUM> when measured according to the longitudinal direction. In some other embodiments not shown on the figures, the front side <NUM> of the liquid chamber <NUM> is curved, or is of the W-shape, whereas the back side is curved or straight.

As mentioned before, the back wall <NUM> of the projection of the liquid chamber <NUM> is pierced with a hole <NUM>, to which either the coolant inlet <NUM> or the coolant outlet <NUM> can be connected. This means that the liquid chamber <NUM> bears the coolant inlet <NUM> or the coolant outlet <NUM>. However, in particular embodiments there can be two liquid chambers, with the liquid chamber <NUM> of the first plate <NUM> corresponding to a first liquid chamber bearing the coolant inlet <NUM> and a second liquid chamber located on the third plate <NUM> bearing the coolant outlet <NUM>, or conversely the liquid chamber <NUM> bearing the coolant outlet <NUM> and the other liquid chamber bearing the coolant inlet <NUM>. These particular embodiments further help distributing the coolant fluid adequately within the heat core <NUM>, thus preventing local boiling in the lateral liquid passes <NUM>, <NUM>.

The present invention thus covers a heat exchanger configured to improve its internal repartition of coolant fluid, in order to ensure that each of its liquid passes is adequately cooled.

Claim 1:
A heat exchanger (<NUM>) configured to cool an air flow with a coolant liquid, comprising a heat core (<NUM>), a first air flow duct located at a first longitudinal end (<NUM>) of said heat core (<NUM>) and a second air flow duct located at a second longitudinal end (<NUM>) of said heat core (<NUM>), the heat core (<NUM>) comprising a plurality of air flow channels (<NUM>) defining liquid passes (<NUM>, <NUM>, <NUM>, <NUM>) in between at least two air flow channels (<NUM>), said heat core (<NUM>) comprising a group of central liquid passes (<NUM>) and two lateral liquid passes (<NUM>, <NUM>) bordering said group of central liquid passes (<NUM>), said heat core (<NUM>) comprising a plurality of plates (<NUM>, <NUM>, <NUM>, <NUM>) enveloping the air flow channels (<NUM>) and the liquid passes (<NUM>, <NUM>, <NUM>, <NUM>), at least one of the plates (<NUM>) having a plane portion and a projection defining a liquid chamber (<NUM>) which is in liquid communication with the liquid passes (<NUM>, <NUM>, <NUM>, <NUM>), characterised in that
the liquid chamber (<NUM>) having a first section (<NUM>) covering at least one of the lateral liquid passes (<NUM>, <NUM>) which is bigger than a second section (<NUM>) covering at least one of the central liquid passes (<NUM>) when the first section (<NUM>) and second section (<NUM>) of the liquid chamber are measured according to the direction in which the air flow channels mainly extend which is a longitudinal direction from the first longitudinal end (<NUM>) to the second longitudinal end (<NUM>) or conversely.