FR3099236A1 - Heat exchanger for cooling and / or heating and / or ventilation and / or air conditioning installation - Google Patents

Abstract

Heat exchanger for a cooling and / or heating and / or ventilation and / or air conditioning installation The invention relates to a heat exchanger (101), for a cooling, heating and / or ventilation and / or air conditioning installation, in particular of a motor vehicle, said exchanger (101) comprising a heat exchange bundle (103) comprising a predefined number of heat exchange elements (105) in which a first heat transfer fluid is intended to flow, said bundle (103) being configured to be traversed by a second fluid intended to thermally exchange with the first heat transfer fluid, characterized in that said exchanger (101) further comprises a predefined number of first hollow fibers (129) configured to receive a phase change material arranged in said beam (103) so as to heat exchange at least with the second fluid. Figure for the abstract: Figure 1

Description

Heat exchanger for cooling and/or heating and/or ventilation and/or air conditioning plant

The present invention relates to a heat exchanger for a motor vehicle ventilation, heating and/or air conditioning installation. The invention also relates to a heating and/or ventilation and/or air conditioning installation comprising such a heat exchanger.

Heat exchangers conventionally comprise a heat exchange bundle and at least one, generally two header boxes for a refrigerant fluid.

The invention relates in particular to heat exchangers using a refrigerant fluid to cool another fluid, such as an evaporator making it possible to cool an air flow passing through it or even an exchanger of the "chiller" type in English or air cooler. water in French.

An evaporator is known, for example, comprising a heat exchange bundle with a stack of tubes or plates allowing heat exchange between a flow of air passing through the heat exchange bundle and the refrigerant fluid, such as a refrigerant fluid , circulating in the tubes or plates.

The evaporator extracts heat energy from the air flow passing through it. However, when the vehicle engine is stopped, the circulation of the refrigerant fluid no longer takes place, and the heat exchange between the flow of air and the refrigerant fluid cannot take place. The air blown into the passenger compartment of the vehicle is then no longer refreshed.

This situation is all the more problematic when the engine is automatically stopped when the car comes to a standstill, frequently depriving the passenger compartment of cooled air. These are in particular motor vehicles equipped with an alternator-starter for the implementation of a device for stopping and restarting the engine automatically, for example stopping the engine at a traffic light or at a stop sign, causes the compressor of the air conditioning circuit to stop operating and therefore the operation of the latter to stop.

In order to remedy the stopping of the cooling of the air blown into the passenger compartment when the engine is stopped, it is known to integrate into the heat exchanger such as an evaporator at least one heat storage means.

In particular, it is known to provide the evaporator with phase change material reservoirs arranged in contact with the tubes in which the refrigerant fluid circulates. Thus, when the vehicle engine is running, the refrigerant cools both the airflow passing through the heat exchanger and the phase change material, which returns the cold to the airflow passing through the heat exchanger. , when the engine is off.

According to a known solution, the internal heat exchanger comprises a plurality of cooling plates having respectively at least one cooling fluid circulation channel and at least one reservoir of phase change material. In particular, the channels of the plates can define undulations or oscillations.

A separation plate is provided between two refrigerating plates and has orifices making it possible to place in communication the channels for circulation of the refrigerating fluid or the reservoirs of the two refrigerating plates.

However, the assembly of the cooling plates as well as the separation plate increases the thickness of the heat exchange bundle compared to that of a conventional evaporator, which increases the pressure drop on the air. Performance is degraded compared to a conventional evaporator.

A chiller or water cooler type exchanger, generally plate type, is also known, in which the refrigerant of an air conditioning loop exchanges heat with a coolant of a thermal regulation loop of storage devices. of electrical energy, such as motor vehicle batteries with electric and/or hybrid motorization.

A so-called fast charging charging technique consists in charging the electrical energy storage device under a high voltage and high amperage, so as to charge it in a short time, for example in a maximum time of twenty minutes. This fast charging involves heating of the electrical storage device that must be treated.

The object of the invention is to at least partially overcome one or more aforementioned drawbacks by proposing an alternative solution making it possible to improve the inertial role of the heat exchanger in the heat transfers, for example for the evaporators in the event of a stoppage of the engine or coolant coolers of the thermal regulation loop of storage devices capable of being fast charged.

Another object of the invention is to reduce the mass and the cost of the heat exchanger.

To this end, the subject of the invention is a heat exchanger, for a cooling, heating and/or ventilation and/or air conditioning installation, in particular of a motor vehicle, said exchanger comprising a heat exchange bundle comprising a predefined number of heat exchange elements in which a first heat transfer fluid is intended to flow, said bundle being configured to be traversed by a second fluid intended to heat exchange with the first heat transfer fluid. According to the invention, said exchanger further comprises a predefined number of first hollow fibers configured to receive a phase change material arranged in said bundle so as to heat exchange at least with the second fluid.

The phase change material encapsulated in the first hollow fibers plays an inertial role in heat transfers. Such fibers can be easily integrated into any heat exchanger, and can be adapted to any configuration or geometry.

The heat exchanger may further include one or more of the following features, taken separately or in combination.

The heat exchanger may in particular be a radiator, such as a cooling radiator of an internal combustion engine, or a heating radiator for the passenger compartment of the vehicle, a high temperature or low temperature radiator, a condenser, or still a charge air cooler, a water cooler, or an evaporator.

According to a variant embodiment, the first hollow fibers are of circular or substantially circular section, and each have an internal diameter of between 0.6 mm and 1 mm.

According to another variant embodiment, the first hollow fibers are of circular or substantially circular section, and each have an internal diameter of the order of 4 mm.

According to one aspect of the invention, the first hollow fibers are arranged downstream of the heat exchange elements of said bundle, in the direction of flow of the second fluid.

The heat exchange elements of said bundle can be made by a plurality of second hollow fibers arranged upstream of the first hollow fibers in the direction of flow of the second fluid. Such an exchanger, using a plurality of fibers to form micro-tubes for the circulation of the first heat transfer fluid, has the advantage of having very large exchange surfaces, and of being able to adapt to any configuration or geometry.

The first and/or second hollow fibers are for example made from a polymer material, in particular from a plastic material. The aluminum tubes or plates of the solutions known from the prior art can be replaced by second polymer fibers, which are lighter and less expensive, without affecting the overall performance of the heat exchanger. The increase in the exchange surface largely compensates for the loss of thermal conductivity compared to a metallic material. The heat exchanger thus also has the advantage of being very light.

The second hollow fibers are generally tubular in shape with a small diameter. More precisely, the second hollow fibers each have an internal diameter of between 0.6 mm and 1 mm. The second hollow fibers have a circular or substantially circular cross-section.

The first and/or second hollow fibers can be arranged in a regular arrangement in the heat exchange bundle.

The first and/or second hollow fibers are free, that is to say they are not encapsulated in a material or a plate, which makes it possible to promote the heat exchange between the two fluids.

According to another aspect of the invention, said exchanger comprises at least one header box into which the heat exchange elements of said bundle open.

The first hollow fibers filled with phase change material can be fixed to an outer wall of said at least one header box, for example by welding.

The invention applies advantageously to heat exchangers in which a refrigerant fluid is intended to flow in the plurality of hollow fibers. The first heat transfer fluid is in this case a refrigerant fluid, and the second fluid is intended to be cooled by the refrigerant fluid.

According to one embodiment, the heat exchanger is configured to work as an evaporator, and the second fluid is an air flow.

According to another embodiment, the heat exchanger is configured to work as a liquid cooler, and the second fluid is a cooling liquid, such as a mixture of water and glycol.

According to a particular embodiment, the heat exchange bundle of an evaporator or a cooler may comprise between three hundred and two thousand second hollow fibers. For such heat exchangers using refrigerant fluid, the second hollow fibers make it possible to have a homogeneous distribution of the refrigerant fluid. Furthermore, the use of hollow fibers of circular section makes it possible to have a high mechanical resistance to pressure, which avoids very penalizing extra thicknesses in the heat exchangers known from the prior art.

According to another aspect of the invention, said bundle is configured for circulation in at least two passes of the second fluid, and the first hollow fibers can be placed in the last pass.

According to yet another aspect of the invention, said exchanger comprises at least one pipe configured to receive phase change material and into which the first hollow fibers open, so as to allow the filling of the first hollow fibers with phase change material. phase.

Said exchanger may comprise a common duct into which the two ends of each first hollow fiber open.

As a variant, said exchanger comprises two ducts into which the two ends of each first fiber respectively open, so as to allow the filling of the first hollow fibers by the flow of the phase change material from one duct to the other.

According to another embodiment, the heat exchange bundle comprises an alternating stack of first channels for the circulation of the first heat transfer fluid and second channels for the circulation of the second fluid. Said exchanger further comprises at least two columns for distributing the second fluid in fluid communication with the second channels for the inlet and the outlet of the second fluid. The first hollow fibers can be arranged in at least one of the columns for distributing the second fluid.

The invention also relates to a cooling and/or heating and/or ventilation and/or air conditioning installation comprising at least one heat exchanger, as defined previously.

Other advantages and characteristics of the invention will appear more clearly on reading the following description given by way of illustrative and non-limiting example, and the appended drawings, among which:

shows a perspective view of a heat exchanger according to a first embodiment comprising first fibers for receiving a phase change material and second fibers for the flow of a heat transfer fluid.

is a view similar to Figure 1 showing a variant of the heat exchanger with a conduit for filling the first fibers.

is another perspective view showing an embodiment of the exchanger with tensioning members of the second fibers.

shows a view of a heat exchanger according to a second embodiment comprising first fibers for receiving a phase change material and second fibers for the flow of a heat transfer fluid received inside a casing.

shows the second fibers arranged in a housing according to another configuration.

schematically represents a heat exchanger according to a third embodiment and first fibers for receiving a phase change material before insertion into the heat exchanger.

In these figures, identical elements bear the same reference numbers.

The following achievements are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference is to the same embodiment, or that the features apply only to a single embodiment. Simple features of different embodiments can also be combined or interchanged to provide other embodiments.

In the description, certain elements can be indexed, such as the first element or the second element, for example. In this case, it is a simple indexing to differentiate and name elements that are close but not identical. This indexing does not imply a priority of one element over another and it is easy to interchange such denominations without departing from the scope of the present description. Nor does this indexing imply an order in time.

With reference to all the figures, the invention relates to a heat exchanger 101, 201, 301 for a motor vehicle cooling, heating and/or ventilation and/or air conditioning installation, of which different embodiments are illustrated.

It may in particular be a radiator, such as a heating radiator for the passenger compartment of the motor vehicle. Alternatively it may be a cooling radiator of an internal combustion engine, a high temperature or low temperature radiator, a condenser, or even a charge air cooler, a water chiller, an evaporator.

In general, the heat exchanger 101, respectively 201, respectively 301 comprises a heat exchange bundle 103, respectively 203, respectively 303 in which a first heat transfer fluid is intended to flow and configured to be traversed by a second fluid. to exchange heat with the first heat transfer fluid. The heat exchange bundle 103, 203, 303 comprises for this purpose a predefined number of heat exchange elements 105, 205, 305, described in more detail below, in which the first heat transfer fluid can circulate and arranged in so as to be exposed to the second fluid. The heat exchange bundle 103, 203, 303 can be configured to allow circulation in one or more passes of the heat transfer fluid, for example for I- or U-shaped circulation. The heat exchanger 101, 201, 301 also comprises an inlet and an outlet of a first heat transfer fluid in fluid communication with the heat exchange elements 105, 205, 305, so that they can be traversed by the first heat transfer fluid. The inlet and the outlet of the first heat transfer fluid can be arranged on the same side or on either side of the heat exchange bundle 103, 203, 303.

Note however that the beam 103 may have an intermediate collector to carry out the passage from one pass to another and that this collector is on the side opposite the input and output collectors.

The heat exchanger 101, 201, 301 further comprises a heat storage means. The thermal storage means is configured to store energy, for example coolness, so as to be able to restore it if necessary. An inertial heat exchanger is thus produced.

The thermal storage means comprises a predefined number of first hollow fibers 129, 229, 329 configured to receive a phase change material known by the acronym PCM for “Phase Change Material” in English. The first hollow fibers 129, 229, 329 are subsequently called PCM fibers 129, 229, 329.

These PCM fibers 129, 229, 329 are arranged downstream of the heat exchange elements 105, 205, 305 of the heat exchange bundle 103, 203, 303, depending on the direction of flow of the second fluid.

The PCM 129 fibers can be isolated from the refrigerant circuit. The PCM fibers 129 can be filled and sealed separately or alternatively collectively. The ends of the PCM fibers 129 can be closed, for example in a non-limiting manner by gluing.

The PCM fibers 129, 229, 329 can be made from a polymer material, in particular from a plastic material. The PCM fibers 129, 229, 329 have for example a thickness between 70 μm and 200 μm.

In addition, the phase change material in the PCM fibers 129, 229, 329 is in particular capable of storing cold temperatures, or calories, and of restoring the stored cold temperatures, or calories. Restitution may occur in particular during a shutdown of the cooling and/or heating and/or ventilation and/or air conditioning and/or electric recharging of the electric batteries.

The PCM fibers 129, 229, 329 can be arranged in a regular arrangement, for example in a constant pattern. The PCM fibers 129, 229, 329 can be arranged parallel to each other.

The heat exchanger 101, 201 or 301 may optionally include one or more members for holding these fibers 129, 229, 329.

First embodiment:

There is shown in Figures 1 to 3 a heat exchanger 101 for a motor vehicle according to a first embodiment.

The heat exchanger 101 according to the first embodiment is for example configured to cool the second fluid intended to pass through it. In this case, the first heat transfer fluid is a coolant coming for example from an air conditioning loop of the motor vehicle. The refrigerant fluid is intended to cool the second fluid, such as an air flow, when it passes through the heat exchanger 101 as shown schematically by the arrows F. The heat exchanger 101 is for example an evaporator.

For reasons of clarity, only a few PCM fibers 129 are represented in FIGS. 1 and 2. The PCM fibers 129 can each have a very small internal diameter, that is to say less than one millimeter, for example between 0, 6mm and 1mm. PCM 129 fibers are generally tubular in shape. More specifically, the PCM fibers 129 each have a circular or substantially circular cross-section.

The heat exchanger 101 such as an evaporator with the PCM fibers 129 is particularly advantageous for a so-called "stop and stay cool" application, that is to say making it possible to maintain a cool temperature in the passenger compartment, for example around 15°C, in the event of automatic engine shutdown when the car comes to a standstill, in particular at a traffic light or at a stop sign, causing the cooling and/or heating and/or ventilation system to stop operating and / or air conditioning.

By way of example, in the case of an evaporator, the phase change temperature may be between 0° C. and 15° C., preferably be 10° C. or approximately. Such a phase change material can give up heat energy by passing into the solid phase and take heat energy by passing into the liquid phase.

In this particular case, the PCM 129 fibers act as a cooling device for the air flow to the passenger compartment, attached to the evaporator.

To do this, the PCM fibers 129 are arranged downstream of the heat exchange elements of the heat exchange bundle 103, an embodiment of which is described in more detail below, according to the direction of flow of the air flow. schematized by the arrows F. Thus, the flow of air intended for the passenger compartment circulates between the heat exchange elements, then around the PCM fibers 129. This makes it possible to effectively exchange energy with the flow of air to improve the comfort of the user, particularly in the event of a stoppage of the installation.

PCM 129 fibers can be filled and sealed separately. The PCM fibers 129 can then be brought into the heat exchange bundle 103.

Alternatively, the heat exchanger 101 may include at least one pipe or reservoir 131 (see Figure 2) to which the PCM fibers 129 can be connected and configured to receive the phase change material so as to allow the filling of the PCM fibers 129 The sealing of the PCM fibers 129 can then be done collectively.

In the example of Figure 2, only one conduit 131 is provided. This solution requires evacuating before filling. The two ends of each PCM fiber 129 open into a common conduit 131. According to a variant not shown, the heat exchanger 101 may comprise two ducts 131 to fill the PCM fibers 129 via a flow of phase change material from one duct 131 to the other through the PCM fibers 129. In this case , each end of the PCM fibers 129 is connected to a conduit 131.

In operation of the heat exchanger 101 as an evaporator, the coolant circulating in the heat exchange elements of said beam 103 cools the air flow to the passenger compartment passing through it. The cooled airflow then circulates around the PCM fibers 129 to in turn cool the phase change material in the PCM fibers 129. In other words, the phase change material gives up heat energy to the airflow .

In the event of the vehicle engine stopping, for example, the phase change material in the PCM fibers 129 can restore the cold (more precisely cold) to the air flow passing through the heat exchanger 101, more precisely the material phase change heater takes heat energy from the airflow. This increases the inertia of the heat exchanger 101 to maintain the cooling of the air flow, without restarting the compressor of an air conditioning loop of the installation for example. Alternatively or in addition, the PCM 129 fibers can complete the cooling of the air flow having passed through the heat exchange elements.

Furthermore, an inlet and an outlet for the refrigerant fluid can be provided on the same side of the heat exchange bundle 103. The heat exchanger 101 comprises at least one header box 107. In the examples illustrated in FIGS. 1 to 3 , the heat exchanger 101 comprises two manifolds 107 arranged on the same side of the heat exchange bundle 103. The manifold or manifolds 107 are intended to be connected with pipes (not shown) for the inlet and the outlet. refrigerant fluid. The collector boxes 107 can be of generally elongated shape.

In particular, depending on the variant in which the PCM fibers 129 are filled and sealed separately before being brought into the heat exchange bundle 103, the ends of the PCM fibers 129 can be fixed to the collector box 107 or one of the manifolds 107, for example the one arranged furthest downstream with respect to the direction of flow of the air flow when the two manifolds 107 are arranged on the same side. The ends of the PCM fibers 129 can be fixed, for example by bonding to an outer wall of the header box 107, as shown schematically in Figure 1.

According to the variant represented in FIG. 2, in which the PCM fibers 129 are collectively filled via one or more ducts 131, the or one of the ducts 131 can be placed adjacent to one of the collector boxes 107, for example that arranged furthest downstream with respect to the direction of flow of the air flow when the two manifolds 107 are arranged on the same side. The conduit 131 can extend parallel to the header box 107. The conduit 131 can be fixed to a header box 107 for example by brazing, and can for this purpose be made of a metallic material such as aluminum.

Furthermore, the heat exchange elements of the heat exchange bundle 103 can be traditional elements, such as a stack of plates assembled two by two so as to define a circulation channel for the coolant, and interposed fins between pairs of plates. Such a configuration is known and is not described in more detail.

Alternatively, the heat exchange elements can be made in the form of second hollow fibers 105. In other words, the heat exchange bundle 103 comprises a plurality of second hollow fibers 105 whose ends each open into a header box 107, so that it can be traversed by the refrigerant. The second fluid, such as the air flow, is intended to flow between the second hollow fibers 105 for heat exchange with the refrigerant fluid.

The second hollow fibers 105 are arranged upstream of the PCM fibers 129 according to the flow direction of the air flow, as shown schematically by the arrows F. The PCM fibers 129 are not in fluid communication with the second hollow fibers 105 or the or collector boxes 107.

The PCM fibers 129 and the second hollow fibers 105 can be sized the same or differently. The PCM fibers 129 and the second hollow fibers 105 can extend in parallel.

For example, the second hollow fibers 105 each have a very small internal diameter, that is to say less than a millimeter, in particular between 0.6 mm and 1 mm. The second hollow fibers 105 are generally tubular in shape. More specifically, the second hollow fibers 105 have a circular or substantially circular cross-section.

For such an evaporator application, the heat exchange bundle 103 comprises for example two thousand or less than two thousand second hollow fibers 105. The heat exchange bundle 103 notably comprises between three hundred and two thousand second hollow fibers 105, and in particular five hundred or around five hundred second hollow fibers 105. In FIGS. 1 to 3, only a few second hollow fibers 105 are shown for greater clarity.

The second hollow fibers 105 are for example made of a polymer material, in particular a plastic material. They replace aluminum tubes, for example known from the prior art, being lighter and less expensive than aluminum tubes.

The second hollow fibers 105 can have a thickness between 50 μm and 70 μm.

The second hollow fibers 105 are sized and arranged so as to improve the performance of the heat exchanger 101 and minimize its cost. This sizing and this arrangement can be done by taking into account in particular the power exchanged, defined from the global exchange coefficient of the heat exchanger, the length of all the hollow fibers, the internal hydraulic efficiency, and the efficiency external hydraulics.

The second hollow fibers 105 can be arranged so as to be exposed directly to the airflow. In the heat exchange bundle 103, the second hollow fibers 105 are free, that is to say they are not encapsulated in a material or a plate, nor arranged inside a tube or the like. . They can thus be directly in contact, without any intermediary, with the flow of air when it passes through the heat exchange bundle 103.

The heat exchange bundle 103 can be devoid of inserts, unlike the known evaporator solutions of the prior art to improve the heat transfer between the air flow and the refrigerant fluid.

In addition, the arrangement of the second hollow fibers 105 in the heat exchange bundle 103 can be regular. By this is meant that the hollow fibers 105 are arranged in a constant pattern, as opposed to a random arrangement. The second hollow fibers 105 can for example be arranged parallel to each other. The second hollow fibers 105 are advantageously arranged with a constant pitch between them. The gap can be maintained between the second hollow fibers 105, so that no hollow fiber 105 comes in contact with another hollow fiber 105, and airflow can circulate around each second hollow fiber 105 with as it passes through the heat exchange bundle 103.

In addition, the hollow fibers 105 can extend mainly along a longitudinal axis L, and in particular straight. The or each manifold 107 may extend transversely (along the axis T) relative to the longitudinal axis L of the hollow fibers 105.

The heat exchange bundle 103 obtained represents a small volume compared to the heat exchange bundles known from the prior art, so that the dimensions and the bulk of the evaporator according to this first embodiment can be reduced by compared to the evaporators of the prior art. Provision can also be made to retain the dimensions of a conventional evaporator, for example to reduce pressure drops on the air flow side.

The heat exchange bundle 103 can be configured for circulation of the coolant in one or more passes, for example between one and six passes, advantageously between two and four passes, in particular in two passes. Such a configuration is easier to manage than a circulation in six or more passes and produces less pressure drop.

In the example illustrated in Figures 1 to 3, the second hollow fibers 105 are arranged to allow circulation in two passes of the refrigerant fluid, called "U" circulation. Such circulation in a "U" or in more than two passes, makes it possible to create fewer pressure drops with the connectors for the inlet and the outlet of the refrigerant fluid at the same place. To do this, the second hollow fibers 105 perform a half-turn on the side opposite the manifolds 107. Other configurations for the circulation of the refrigerant fluid are possible.

Furthermore, the second hollow fibers 105 can have lengths of the order of 400mm to 1500mm. For example, provision can be made, without limitation, around a thousand second hollow fibers 105 of 1000 mm or around two thousand hollow fibers of 500 mm. The second hollow fibers 105 may or may not be of the same length. Depending on the case, the integration of the second hollow fibers 105 in the collector box(es) 107 is different.

The collector box(es) 107 may be provided to bring together the second hollow fibers 105, as shown in FIGS. 1 to 3, so that their ends open into the pipes (not shown) for the inlet and the outlet of the refrigerant fluid.

More precisely, the second hollow fibers 105 can all be joined together at their ends. Each packet of ends of second hollow fibers 105 is arranged so as to open out into an inlet or outlet pipe (not shown) for the refrigerant fluid. To do this, a packet of ends of second hollow fibers 105 is arranged at the entrance of a manifold 107 and the other packet of ends of second hollow fibers 105 is arranged at the exit of another or the same collector box 107. The heat exchanger 101 advantageously comprises for this purpose at least one member 123 for holding the ends of the second hollow fibers 105, for example made in the form of a plate. This holding member 123 such as a plate is arranged at the inlet or the outlet of the header box 107 at the interface with the inlet or outlet tubing (not shown). Sealing can be ensured at the interface between the refrigerant inlet or outlet pipe (not shown) and the header box 107. The second hollow fibers 105 each extend into the header box 107, after the input, respectively the output, until reaching the point where to exit from the collector box 107, via an orifice (not shown) such as a groove or a circular hole for example. Such a configuration has the advantage of having a homogeneous distribution of the coolant in the second hollow fibers 105. Indeed, all the second hollow fibers 105 are connected at the same place to the inlet pipe (not shown), so that they are all fed the same way. This solution requires different lengths of second hollow fibers 105 . Finally, this solution makes it possible to advantageously reduce the mass of the entire evaporator.

Alternatively, the coolant can be intended to circulate in the collector box or boxes 107, which then make it possible to distribute the coolant in the second hollow fibers 105 or to collect the coolant that has traveled through the second hollow fibers 105. The ends of the second hollow fibers 105 then each open into a header box 107 or a compartment of a header box 107 common.

According to a second variant (not shown), the second hollow fibers 105 can emerge individually by being distributed along the header box 107. Such a configuration is simple to implement. This solution makes it possible to have the same length for all the second hollow fibers 105. Sealing must be ensured at the interface of each hollow fiber 105 and the header box 107.

A third variant (not shown) is a hybrid solution between the first and second variants. According to this third variant, second hollow fibers 105 of the same length can be joined together at their ends which are placed at the inlet or at the outlet of the header box 107. The second hollow fibers 105 each extend into the header box 107, after the 'inlet, respectively the outlet, until reaching the place where to leave the header box 107. To do this, the length of the second hollow fibers 105 is chosen long enough to reach the furthest point. Provision is also made for each hollow fiber 105 to return inside the header box 107 before leaving the header box 107. In order to prevent the second hollow fibers 105 from being distended inside the header box 107 , it is possible to provide one or more holding members (not shown) for the second hollow fibers 105 arranged inside the header box 107, such as holding grids through which the second hollow fibers 105 pass.

Furthermore, whatever the alternative embodiment for assembling the second hollow fibers 105 to the header box 107, the heat exchanger 101 advantageously comprises at least one member for tensioning the second hollow fibers 105. This makes it possible to prevent the second hollow fibers 105 from being subjected to the phenomenon of resonance.

According to the embodiment of Figure 3, this tensioning can be achieved using at least one axis 125. This is in particular an axis 125 which can be cylindrical. In this example, a single pin 125 is provided. In Figure 3, PCM fibers 129 are not shown for clarity.

With an arrangement of the second hollow fibers 105 allowing circulation in a "U", such an axis 125 is arranged on the side of the heat exchange bundle 103 which is opposite the coolant inlet and outlet. The axis 125 extends transversely relative to the longitudinal axis L of the second hollow fibers 105. The second hollow fibers 105 can thus perform a half-turn around this axis 125. The axis 125 has a sufficient diameter so as not to be below the radius of curvature of the second hollow fibers 105, for example a diameter of at least 5 mm.

The heat exchanger 101, more precisely the heat exchange bundle 103, may comprise cheeks 109 on either side of all the second hollow fibers 105 of the heat exchange bundle 103. These cheeks 109 can be configured to hold the pin 125. For this purpose, each end of the pin 125 can be inserted into a complementary opening 110 provided on the corresponding flange 109. The end of the shaft 125 can be mounted tight in the opening 110 of the flange 109 (see figure 3) or according to an alternative not shown with a game.

As a variant or in addition, the tensioning members may also comprise one or more elastic compensation members 127. The elastic compensation member(s) 127 are configured to compensate for an expansion or retraction of the second hollow fibers 105 in operation of the evaporator, due to the internal temperature and/or pressure, for example when the refrigerant fluid circulates in the second hollow fibers 105, greatly lowering the temperature. This prevents the breakage of the second hollow fibers 105 in operation.

The elastic compensation member 127 is for example made in the form of a spring, such as a coil spring. Such springs make it possible to tension and keep the second hollow fibers 105 in tension, thus avoiding possible vibrations and a phenomenon of resonance. Other variants are possible, for example as one or more elastic blades or even a shape memory material.

The elastic compensation member(s) 127 are arranged in connection on the one hand with the or one of the manifolds 107 and on the other hand with at least one element of the heat exchange bundle 103. According to the exemplary embodiment shown schematically in Figure 3, the springs are arranged in conjunction with a manifold 107 and a flange 109. According to an alternative not shown, the springs can for example be arranged in conjunction with a manifold 107 and the axis 125. In this case, the flanges 109 are fixed relative to the manifold 107 or to the manifolds 107, and the tensioning is achieved by adjusting the positioning of the axis 125.

Second embodiment:

Figures 4 and 5 schematically illustrate a second embodiment. Only the differences with respect to the first embodiment are detailed below.

According to the second embodiment, the heat exchanger 201 is a liquid cooler, called "chiller" in English. In this case, the second fluid is for example a cooling liquid, such as a mixture of water and glycol.

Such a heat exchanger 201 is generally interposed between a circuit of the first heat transfer fluid, such as the coolant, and a circuit of the second fluid, such as the coolant. The circuit of the first heat transfer fluid can be part of an air conditioning loop used to cool the air in the passenger compartment of the motor vehicle. The circuit of the second fluid can be part of a thermal regulation loop of an electrical and/or electronic component capable of releasing heat during their operation, such as a battery, a battery module or storage elements of 'electric energy.

The heat exchanger 201 is a dual fluid circulation exchanger, that is to say it defines a closed enclosure, intended to be traversed by the two fluids, namely here the refrigerant fluid and the cooling liquid. To do this, the heat exchanger 201 comprises a casing 202 or casing in which the heat exchange bundle 203 is arranged. The box 202 can have a generally parallelepiped, tank or enclosure shape. In the particular example of Figure 4 or 5, the housing 202 is generally parallelepipedic in shape with three pairs of opposite faces 202a, 202b, 202c. It is a closed box 202, apart from the inlets and outlets of the two fluids, and not open so as to be crossed by a flow of air as in the first embodiment previously described.

The housing 202 comprises at least four openings or connectors such as pipes, for the inlets and outlets of the two fluids, respectively configured to be connected to the circuit of the corresponding fluid.

More specifically, the housing 202 comprises at least two openings or connectors 204 for the inlet and the outlet of the first fluid such as the refrigerant, the circulation of which is shown diagrammatically by the arrows F1 in FIG. 4, and intended to be connected to the circuit refrigerant fluid. The inlet and the outlet 204 of the refrigerant fluid can for example be provided on the same face, for example 202b, of the housing 202.

The housing 202 also comprises at least two openings or connectors 206 for the inlet and the outlet of the second fluid such as the coolant, the circulation of which is shown schematically by the arrows F2 in FIG. 4, and intended to be connected to the circuit of the cooling liquid.

In addition, the openings or connectors 204 for the refrigerant fluid and 206 for the cooling liquid can be arranged on different faces of the housing 202 as in the example of FIG. 4, alternatively at least one opening or connectors 204 for the refrigerant fluid and at least one opening or connectors 206 for the cooling liquid can be arranged on the same face of the housing 202, or even all the openings or connectors 204 and 206 can be arranged on the same face of the housing 202, for example the same face 202a as in the example of Figure 5. Depending on the arrangement of the openings or connectors 204 and 206, the two fluids can circulate in co-current within the housing 202, as shown schematically by the arrows F1 and F2 in the figure 4, or alternatively, against the current.

According to the exemplary embodiments illustrated in FIGS. 4 and 5, the heat exchange elements are produced by a plurality of second hollow fibers 205. For such a cooler or “chiller” application, the heat exchange bundle 203 comprises by example less than two thousand second hollow fibers 205, in particular between three hundred and two thousand second hollow fibers 205 with an internal diameter of between 0.6 mm and 1 mm, in which the coolant is intended to flow and between which the coolant is intended to circulate. In Figures 4 and 5, only a few second hollow fibers 205 are shown for clarity.

The second hollow fibers 205 can be of different lengths or of the same length. The second hollow fibers 205 can have lengths of the order of 150mm to 400mm, for example one can provide in a non-limiting way five hundred second hollow fibers 205 of 340mm or one thousand second hollow fibers 205 of 170mm.

The ends of each hollow fiber 205 open out one into the orifice or the connector 204 for the inlet of the refrigerant fluid and the other in the orifice or the connector 204 for the outlet of the refrigerant fluid. For reasons of clarity, the ends of the second hollow fibers 205 brought together to emerge at the level of the connectors 204 are not illustrated in FIG. 5. Sealing can be ensured at the level of the connectors 204 for the refrigerant fluid. When the cooling liquid circulates in the heat exchanger 201, the second hollow fibers 205 are then immersed or bathed in this cooling liquid.

As a variant, it is possible to envisage that the fluid flowing inside the second hollow fibers 205 is the cooling liquid, and that the cooling fluid circulates between the second hollow fibers 205. The previous solution according to which the cooling fluid is flows inside the second hollow fibers 205 is more advantageous, due to the pressure of the refrigerant fluid. Indeed, in this case the second hollow fibers 205 more effectively maintain the pressure forces involved, corresponding to the pressure multiplied by the surface, because the internal surface of the second hollow fibers 205 is smaller than the external surface.

The second hollow fibers 205 can be distributed for circulation of the first fluid such as the refrigerant fluid in one or more passes. In the example of Figure 4, the second hollow fibers 205 allow circulation in a so-called "I" pass. As a variant, as illustrated in FIG. 5, the second hollow fibers 205 are arranged to allow circulation in two passes of the refrigerant fluid, referred to as “U” circulation. To do this, the second hollow fibers 205 perform a half-turn within the housing 202 on the side opposite the openings or connectors 204 for the inlet and the outlet of the refrigerant fluid.

For such a two-pass configuration of the coolant, the second fluid such as the coolant intended to flow inside the housing 202 can also follow a so-called “U” circulation. To this end, the heat exchanger 201 may comprise at least one partition 233 arranged inside the casing 202, so as to define two coolant passes, in co-current or alternatively in counter-current by relative to the refrigerant. This partition 233 can extend within the housing 202 between the internal walls of the two opposite faces 202c while also coming to bear against the internal wall of the face 202a having the openings or connectors 206 for inlet and outlet of the liquid cooling by being between them. On the side opposite the openings or connectors 206, that is to say at the level of the other face 202a, the partition 233 ends at a predefined distance from the internal wall of the box 202, so as to allow the half - turn of the coolant. The partition 233 is also inside the loops formed by the second hollow fibers 205 by performing the U-turn for the “U” circulation.

As for the second embodiment, the heat exchanger 201 advantageously comprises at least one member for tensioning the second hollow fibers 205.

According to an exemplary embodiment illustrated in FIG. 5, this tensioning can be carried out using one or more holding grids 235. In particular, at least two holding grids 235 can be arranged at a distance from one on the other, and the second hollow fibers 205 extend between these grids 235. The retaining grids 235 are crossed by the second hollow fibers 205, maintaining them and guaranteeing the pitch between the second hollow fibers 205. Furthermore, when the partition wall 233 is provided, the retaining grid(s) 235 can be maintained between an internal wall of the box 202 and this partition wall 233. In addition, in the configuration of the second hollow fibers 205 allowing circulation in a "U of the coolant fluid, one of the retaining grids 235 can be arranged, at the level of the half-turn of the second hollow fibers 205, on the side opposite to the connectors 204 for the coolant fluid inlet and outlet.

As a variant or in addition, for the tensioning of the second hollow fibers 205, one can provide an axis (not shown in Figure 5), similar to the axis 125 described with reference to Figure 3 of the first embodiment, arranged on the side opposite the coolant inlet and outlet 204, around which the second hollow fibers 205 can perform their half-turn.

Unlike the first embodiment, the shaft 125 (not shown) does not pass through the walls of the housing 202 for sealing reasons, and therefore cannot be provided to be mobile, being mounted with a clearance in a complementary orifice of the housing 202. On the contrary, such an axis (not shown) extends within the housing 202 between two opposite faces, for example the faces 202c, and can be held by these two opposite faces. Such an axis (not shown) must, as before, have a sufficient diameter not to be below the radius of curvature of the hollow fibers 205, for example a diameter of at least 5 mm.

The heat exchanger 201 further comprises a heat storage means made by the PCM fibers 229. For reasons of clarity, only a few PCM fibers 229 are represented in FIG. 4, and the PCM fibers 229 are not illustrated in FIG. 5. PCM fibers 229 and second hollow fibers 205 may or may not extend parallel.

Similarly to the first embodiment, the thermal storage means is configured to store energy, in particular coolness, so as to be able to restore it if necessary. An inertial cooler is thus produced.

The heat exchanger 201 such as a cooler with a heat storage means can in particular be advantageous for cooling the coolant used to cool an electrical energy storage device such as a battery, a battery module, intended to be charged according to a charging technique called fast charging, under a high voltage and high amperage, in a short time, when the vehicle is stationary, and which involves heating of the electrical storage device.

Such a heat exchanger 201 can also be advantageous for absorbing temperature peaks thanks to the heat storage means having the role of a thermal buffer, for example when significant heat loads are to be evacuated, without requiring the heat exchanger to be oversized. 201.

The characteristics of the PCM fibers 229 can be similar to those of the PCM fibers 129 previously described with reference to the first embodiment. Only the differences are detailed below.

The PCM fibers 229 can be filled and sealed separately and then be placed inside the casing 202. As a variant, the heat exchanger 201 can include at least one duct or tank (not shown) into which the ends of the fibers can emerge. PCM 229. Such a conduit (not shown) can be fixed to the housing 202 for example by soldering. As described with reference to the first embodiment, a single conduit may be provided for filling the PCM fibers 229 or alternatively two conduits may be provided to fill the PCM fibers 229 by flow of phase change material from one conduit to the other.

The PCM fibers 229 are arranged downstream of the second hollow fibers 205 according to the direction of flow of the coolant shown schematically by the arrows F2. The PCM fibers 229 received inside the casing 202 are also immersed in the cooling liquid when it circulates within the casing 202. The cooling liquid flows between the PCM fibers 229 after having passed through the second hollow fibers 205 through which the refrigerant flows.

Alternatively, in the case of circulation in several passes of the fluids, the PCM 229 fibers can be placed in a dedicated pass, in particular at the level of the last pass of the coolant where it is the coldest. For example, according to a configuration allowing circulation in a "U", in particular as described with reference to FIG. 5, the PCM fibers 229 are advantageously placed at the level of the second coolant pass downstream of the second hollow fibers 205.

The characteristics of the phase change material are similar to the first embodiment except that the exchange of negative calories/calories takes place with the coolant in which the PCM 229 fibers are immersed.

Thus, in operation of the heat exchanger 201, the coolant is cooled in contact with the second hollow fibers 205 and then passes through the PCM fibers 229 to in turn cool the phase change material contained in these PCM fibers 229.

If the vehicle stops for example, the coolant no longer circulates in the second hollow fibers 205, the coolant which can continue to circulate as needed is then cooled by the PCM fibers 229. This makes it possible to evacuate the heat of the energy storage device such as the batteries for example in the event of fast charging, by the circulation of the cooling liquid through the batteries where it recovers their heat which is then evacuated by the heat exchanger 201.

As a variant or in addition, the PCM fibers 229 can complete the cooling of the coolant having circulated around the second hollow fibers 205, for example if the flow rate of the refrigerant fluid is not high enough. The PCM 229 fibers make it possible to limit the rise in temperature.

Third embodiment:

FIG. 6 schematically represents a heat exchanger 301 according to a third embodiment.

Similar to the second embodiment, it is for example a liquid cooler, called "chiller" in English.

This third embodiment differs from the second embodiment in that the heat exchange elements comprise an alternating stack 305 of first channels for the circulation of the first heat transfer fluid such as the refrigerant fluid and second channels for the circulation of the second fluid such as coolant.

The circulation channels can be defined by pairs of plates. For example, first plates are assembled in pairs so as to define between them the first circulation channels for the coolant. Similarly, second plates are assembled in pairs, so as to define between them a circulation channel for the coolant. These plates are generally made of a metallic material and can be stamped and brazed together.

The heat exchanger 301 thus defines a closed internal volume intended to be traversed by the two fluids, by the two fluids, namely here the refrigerant and the cooling liquid. It is nevertheless entirely possible to replace the pairs of plates with other heat exchange elements between two fluids such as flat tubes or the like without departing from the scope of the invention.

To increase the heat exchange, at least some plates of the stack 305 may have a multitude of deformations 337, such as bosses on their interior surfaces, that is to say their surfaces facing the other plate forming a pair. Thus, these bosses form a projection in the flow circuit of the corresponding fluid.

Furthermore, the heat exchanger 301 comprises at least two columns 339 for distributing the first fluid in fluid communication with the first channels, for the inlet and the outlet of the refrigerant fluid. The heat exchanger 301 also comprises at least two columns 341 for distributing the second fluid, in fluid communication with the second channels for the inlet and the outlet of the coolant.

The heat exchanger 301 comprises for example two openings or connectors 304 such as pipes or flanges for the inlet and the outlet of the refrigerant fluid, intended to be connected to the circuit of the refrigerant fluid. The first plates include orifices in fluid communication with these openings or connectors 304, so as to allow the circulation of the refrigerant fluid between the first plates. The openings or connectors 304 and the orifices provided on the first plates form the columns 339 for distributing the refrigerant fluid.

The heat exchanger 301 also comprises two openings or connectors 306 such as pipes or flanges for the inlet and the outlet of the cooling liquid, intended to be connected to the circuit of the refrigerant fluid. These openings or connectors 306 are arranged opposite to the openings or connectors 304. The second plates include orifices in fluid communication with the openings or connectors 306, so as to allow the circulation of the cooling liquid between the second plates. The openings or connectors 306 and the orifices provided on the second plates form the columns 341 for distributing the coolant.

Depending on the arrangement of the openings or connectors 304 and 306, the two fluids can circulate against the current, as shown schematically by the arrows F1 and F2 in FIG. 6.

Furthermore, the plates of the stack 305 can be configured to allow circulation in at least two passes of each fluid. In the example shown schematically in Figure 6, the two fluids flow in two passes, according to a so-called “U” circulation. To do this, in known manner, the plates may respectively comprise at least one rib, for example a central rib, making it possible to delimit two passes. Such a rib does not extend over the entire length of the plates in such a way as to allow the corresponding fluid to turn around.

According to this third embodiment, the thermal storage means is produced by the PCM fibers 329 configured to receive the phase change material arranged in at least one of the columns 341 for distributing the coolant. For clarity, only a few PCM fibers 329 are shown in Figure 6. PCM fibers 329 can be arranged in each of the two coolant distribution columns 341, as shown by the dotted arrows in Figure 6.

The PCM fibers 329 can be arranged directly, without intermediary in the column(s) 341 for distributing the coolant. In this case, the PCM fibers 329 are directly in contact with the coolant when it circulates in the heat exchanger 301. As a variant, the PCM fibers 329 can for example be arranged in a cartridge or a tube 343, at its tower arranged in a column 341 for distributing the coolant. Such a cartridge has for example an outer diameter of between 10mm and 20mm. The cartridge 343 is for example in a polymer material. For example, two cartridges 343 of PCM fibers 329 can be provided.

The PCM fibers 341 are advantageously of circular or substantially circular cross-section. Depending on the variant of integration of the PCM 329 fibers in the heat exchanger 301, their sizing may differ. By way of non-limiting example, when the PCM fibers 329 are arranged directly, without intermediary, in a column 341 for distributing the coolant, the PCM fibers 329 can each have an internal diameter, for example around 4 mm. When the PCM fibers 329 are encapsulated in a cartridge or tube 343, their internal diameters can be very small, in particular less than one millimeter, for example between 0.6 mm and 1 mm.

Similar to the second embodiment, the PCM fibers 329 are configured to store energy, in particular coolness, so as to be able to restore it if necessary. The characteristics of the phase change material and the PCM fibers 329 are similar to the second embodiment. Only the differences are detailed below.

The PCM fibers 329 can be filled and sealed separately and, optionally after having been encapsulated in a cartridge 343, then be placed in the heat exchanger 301, more precisely in one or more columns 341 for distributing the coolant, without blocking them. , so as not to impede the flow of the coolant in the stack 305 of plates. The PCM fibers 329 are thus also arranged in thermal contact with the first plates between which the refrigerant fluid circulates.

Thus, in operation of the heat exchanger 301, the phase change material contained in the PCM fibers 329 is cooled by conduction by the refrigerant fluid circulating in the first circulation channels, for example defined between the first plates. In the event of the vehicle stopping, for example, when the coolant no longer circulates in the stack 305, the coolant which can continue to circulate as needed is then cooled by the PCM fibers 329.

Thus, the PCM fibers 129, 229, 329 according to either of the previously described embodiments simply form a thermal storage means configured to store energy, in particular coolness, so as to be able to restore it. if necessary, which can be easily integrated into any heat exchanger, so as to produce an inertial heat exchanger.

In particular, in the case of a "stop and stay cool" evaporator, the PCM 129 fibers make it possible to maintain a cool temperature in the passenger compartment, in the event of automatic engine shutdown when the car comes to a standstill, resulting in the stopping the operation of the cooling and/or heating and/or air conditioning installation, in particular of the compressor of such an installation.

In the case of a cooler, the PCM fibers 229, 329 are particularly advantageous for cooling the coolant used to cool a battery charged in fast charge.

The PCM 129, 229, 329 fibers also make it possible to absorb temperature peaks or complete the cooling when the cooling capacity is not sufficient.

In the examples described, the PCM fibers 129, 229, 329 make it possible to store freshness, to restore it if necessary. The invention also applies to applications requiring the storage of calories and the release of heat if necessary.

Claims (10)

Heat exchanger (101, 201, 301), for a cooling, heating and/or ventilation and/or air conditioning installation, in particular for a motor vehicle, said exchanger (101, 201, 301) comprising a heat exchange bundle (103, 203, 303) comprising a predefined number of heat exchange elements (105, 205, 305) in which a first heat transfer fluid is intended to flow, said bundle (103, 203, 303) being configured to be crossed by a second fluid intended to exchange heat with the first heat transfer fluid, characterized in that said exchanger (101, 201, 301) further comprises a predefined number of first hollow fibers (129, 229, 329) configured to receive a change material phase arranged in said beam (103, 203, 303) so as to heat exchange at least with the second fluid. Exchanger (101, 201, 301) according to claim 1, in which the first hollow fibers (129, 229, 329) are of circular section and each have an internal diameter of between 0.6 mm and 1 mm. Exchanger (101, 201) according to any one of claims 1 or 2, in which the first hollow fibers (129, 229) are arranged downstream of the heat exchange elements (105, 205) of said bundle (103, 203) , depending on the direction of flow of the second fluid. Exchanger (101, 201) according to the preceding claim, in which the heat exchange elements of said bundle are produced by a plurality of second hollow fibers (105, 205) arranged upstream of the first hollow fibers (129, 229) in the direction flow of the second fluid. Exchanger (101, 201) according to the preceding claim, in which the second hollow fibers (105, 205) are of circular section and each have an internal diameter of between 0.6 mm and 1 mm. Exchanger (101) according to any one of claims 1 to 5, comprising at least one header box (107) into which the heat exchange elements (105) of said bundle (103) open, and into which the first hollow fibers ( 129) filled with phase change material are attached to an outer wall of said at least one header box (107). Exchanger (101, 201) according to any one of claims 1 to 5, comprising at least conduit (131) configured to receive phase-change material and into which the first hollow fibers (129, 229) open, for filling first hollow fibers (129, 229) of phase change material. Exchanger (101, 201) according to claim 7, in which the two ends of each first hollow fiber (129, 229) open into a common duct (131). Exchanger (101, 201) according to claim 7, comprising two ducts into which the two ends of each first hollow fiber (129, 229) respectively open. Exchanger (301) according to any one of claims 1 or 2, in which the heat exchange bundle (303) comprises an alternating stack of first channels for the circulation of the first heat transfer fluid and second channels for the circulation of the second fluid , said exchanger (301) further comprising at least two columns (341) for distributing the second fluid in fluid communication with the second channels for the inlet and the outlet of the second fluid, and in which the first hollow fibers (329) are arranged in at least one of the columns (341) for distributing the second fluid.