Patent Application
20240377140
The present invention relates to the field of refrigerant loops for motor vehicles, and more specifically for electric or hybrid vehicles.
An electric or hybrid vehicle has a motor vehicle heating, ventilation and/or air-conditioning installation and a refrigerant loop which are configured so as to vary the temperature in the vehicle interior, and notably so as to heat the latter through the winter and cool it through the summer. The vehicle-interior temperature is notably modified by means of the refrigerant circulating in the refrigerant loop between a heat-exchange device arranged in the vehicle in the vicinity of the vehicle interior, and a heat exchanger arranged in contact with the ambient air on the front face of the vehicle. Thus, the refrigerant circulating in the refrigerant loop absorbs or cedes heat energy in the heat exchanger or the heat-exchange device depending on the vehicle-interior cooling or heating requirements. The use of a compressor and, where appropriate, of an expansion valve is notably required in order to modify the pressure of the refrigerant in the refrigerant loop so as to thermodynamically modify the temperature of the refrigerant which is subsequently made to pass through the heat-exchange device and the heat exchanger.
The heat exchanger in the front face of the vehicle allows the exchange of heat energy between the refrigerant, which circulates in the tubes disposed one above another and spaced apart from one another by fins, and a stream of air which comes from outside the vehicle and passes through said heat exchanger between the tubes at the fins.
In electric or hybrid vehicles, it is known practice to configure the refrigerant loop and the heat exchanger in the front face so as to form a reversible heat pump within which the heat exchanger is able to operate in condenser mode, in summer, to ensure the cooling of the vehicle interior via the heat-exchange device forming an evaporator in the heating, ventilation and/or air-conditioning installation, and to operate in evaporator mode, in winter, to ensure the heating in the vehicle interior via the heat-exchange device forming a condenser.
One problem with such a heat exchanger positioned in the front face of the vehicle then resides in its operation in evaporator mode, when the temperature difference tends to heat the stream of humid air and create droplets of condensation which are deposited on the surface of the heat exchanger. If the temperature of the refrigerant circulating in the tubes is too low, and the fins between the tubes are too cold owing to thermal conduction, the cooling of the droplets of condensation can cause the local formation of frost on the fins between the tubes of the heat exchanger. Such a presence of frost generates obstacles to the passage of air through the heat exchanger and thus tends to reduce the thermal capacity of the heat exchanger.
The present invention seeks to overcome this disadvantage by proposing a refrigerant loop and, more particularly, a heat exchanger, able to limit the formation of ice thereon. The invention therefore helps to increase the heat-exchange capacity of the heat exchanger, and therefore of the refrigerant loop.
Thus a main subject of the invention is a heat exchanger for a refrigerant loop, comprising a heat-exchange surface, a first refrigerant header and a second refrigerant header which are positioned respectively at a first longitudinal end of the heat-exchange surface and at a second longitudinal end of the heat-exchange surface, characterized in that at least one of the refrigerant headers is divided into a first collecting chamber and a second collecting chamber which are separated by a dividing wall, each of these collecting chambers respectively comprising a fluid inlet portion and a fluid outlet portion, and in that a connecting device associated with the at least one refrigerant header comprises a refrigerant inlet duct divided into a first fluid inlet channel coupled to the fluid inlet portion of the first collecting chamber and a second fluid inlet channel coupled to the fluid inlet portion of the second collecting chamber, and a refrigerant outlet duct making the connection between a first fluid outlet channel coupled to the fluid outlet portion of the first collecting chamber and a second fluid outlet channel coupled to the fluid outlet portion of the second collecting chamber.
The refrigerant loop may be positioned within a vehicle, for example a hybrid or electric vehicle, in order to cool or heat the interior of this vehicle. The heat exchanger may be an evaporator-condenser in which the refrigerant circulates. This heat exchanger comprises the heat-exchange surface in which heat energy is exchanged between an air flow intended to pass through said exchange surface and the refrigerant circulating inside the tubes of this exchange surface, the refrigerant capturing or ceding heat energy with respect to the air flow depending on the configuration of the refrigerant loop, intended to cool or to heat the vehicle interior.
The dividing wall extends across a header to delimit two collecting chambers within the same refrigerant header, such that the first collecting chamber and the second collecting chamber are fluidically separate. The refrigerant caused to circulate in one of the collecting chambers is able to circulate only in the tubes associated with that collecting chamber.
Within the at least one refrigerant header, the first collecting chamber and the second collecting chamber each comprise both a fluid inlet portion and a fluid outlet portion. These fluid inlet portions and these fluid outlet portions are therefore grouped together within the same refrigerant header. Thus, fluid inlets and outlets can be located on a single refrigerant header. Such a layout makes it possible to avoid having fluid inlet portions on a first header at one longitudinal end of the heat-exchange surface, and fluid outlet portions on a second header at the other longitudinal end of this heat-exchange surface. The connections and couplings necessary for supplying the heat-exchange surface are therefore simplified since the inlet and outlet portions are located at the one same longitudinal end of the heat-exchange surface.
The heat exchanger thus advantageously has a single connecting device, this connecting device being equipped with two fluid inlet channels and with two fluid outlet channels. Each of these channels is coupled to one of the fluid inlet or outlet portions of the collecting chambers of the at least one refrigerant header.
According to one feature of the invention, the connecting device comprises a connection fitting fixed to the at least one refrigerant header, and in which the two fluid inlet channels and the two fluid outlet channels are formed.
According to one feature of the invention, the fluid inlet and fluid outlet channels are coupled to one of the collecting chambers via tubular elements able to attach the body of the connection fitting to the at least one refrigerant header.
These tubular elements notably enable the body of the connection fitting to be positioned on the at least one refrigerant header some distance away from the fluid inlet or outlet portion that accepts the corresponding fluid inlet or fluid outlet channel. Conversely, if the body of the connection fitting is positioned directly facing the corresponding fluid inlet or outlet portions, the fluid inlet or outlet channels are coupled directly to the corresponding header, without tubular elements.
According to one feature of the invention, the tubular elements are arranged in the continuation of a main plane of elongation of the heat-exchange surface.
This particular layout of the tubular elements makes it possible to limit the bulk of the heat exchanger within the vehicle in which it is intended to be fitted.
According to one feature of the invention, the two inlet channels formed in the connection fitting extend perpendicular to one another, and/or wherein the two outlet channels formed in the connection fitting extend perpendicular to one another.
According to one feature of the invention, the heat-exchange surface comprises tubes configured to channel the refrigerant, these tubes extending longitudinally between the first refrigerant header and the second refrigerant header, the tubes being distributed as two sets of tubes, the tubes of a first set opening into the first collecting chamber of the at least one refrigerant header and the tubes of a second set opening into the second collecting chamber of the at least one refrigerant header.
In this way, the tubes allow the refrigerant to circulate within the heat-exchange surface, and convey the fluid either to or from the first collecting chamber or to or from the second collecting chamber.
According to one feature of the invention, the tubes are stacked in a direction of stacking as an alternation of tubes of the first set alternating with tubes of the second set.
It will be appreciated that the tubes are stacked in such a way that the heat-exchange surface comprises an alternation of one tube of the first set alternating with one tube of the second set. This alteration thus forms a layout pattern which is repeated from one end of the heat-exchange surface to the other in a direction of stacking of the tubes which is perpendicular to the direction of elongation thereof.
According to one feature of the invention, the first collecting chamber and the second collecting chamber of the at least one refrigerant header are aligned in a longitudinal direction, the first collecting chamber being situated between the heat-exchange surface and the second collecting chamber, the tubes of the first set having a longitudinal dimension that is less than a longitudinal dimension of the tubes of the second set, these longitudinal dimensions being measured between a midplane extending perpendicular to the heat-exchange surface and the at least one refrigerant header.
It will thus be appreciated that the first collecting chamber is interposed, in a longitudinal direction, between the heat-exchange surface and the second collecting chamber.
The midplane, which extends at equal distances from the first header and from the second header, divides the heat exchanger into two symmetrical, or at the very least substantially equivalent, parts, given that the supply and removal ducts can be coupled at different zones on one header compared with the other without that fact preventing the plane perpendicular to the heat-exchange surface and equidistant from the headers being able to be considered to be a midplane within the meaning of the invention.
The length of extension of a tube, which differs from its longitudinal dimension, may also be considered. The length of extension is measured from a first longitudinal end of the tube to the second longitudinal end thereof, namely from the first refrigerant header to the second refrigerant header, and the longitudinal dimension is measured between the midplane and the first refrigerant header.
According to one optional feature of the invention, the second refrigerant header is divided into two collecting chambers, the tubes of the first set opening into a first collecting chamber and the tubes of the second set opening into a second collecting chamber, the tubes of the first set and the tubes of the second set having different lengths of extension.
In other words, in a first embodiment in which the tubes have different lengths of extension from one set of tubes to the other, the length of extension of the tubes of the first set is such that these tubes extend, at one of their longitudinal ends, as far as the first collecting chamber of the first header and, at the other of their longitudinal ends, as far as the first collecting chamber of the second header. Conversely, the tubes of the second set have a length of extension such that these tubes extend, at one of their longitudinal ends, as far as the second collecting chamber of the first header and, at the other of their longitudinal ends, as far as the second collecting chamber of the second header.
According to another optional feature of the invention, the second refrigerant header is divided into two collecting chambers, the tubes of the first set opening into a second collecting chamber and the tubes of the second set opening into a first collecting chamber, the tubes of the first set and the tubes of the second set having the same lengths of extension.
In other words, in a second embodiment in which the tubes all have the same length of extension from one set of tubes to the other, the tubes of the first set open into the first collecting chamber of the first header and into the second collecting chamber of the second header, whereas the tubes of the second set open into the second collecting chamber of the first header and into the first collecting chamber of the second header.
According to another feature of the invention, the heat exchanger comprises at least a first refrigerant circuit consisting of the first fluid inlet channel of the connecting device, of the fluid inlet portion of the first collecting chamber of the first refrigerant header, which is fluidically connected to the tubes of the first set, of the tubes of the first set, of the first collecting chamber of the second header, which is fluidically connected to the tubes of the first set, of the fluid outlet portion of the first collecting chamber of the first refrigerant header, which is fluidically connected to the tubes of the first set and of the first fluid outlet channel, the first fluid inlet channel being configured to be fluidically connected to a first portion of the refrigerant loop and the first fluid outlet channel being configured to be fluidically connected to a second portion of the refrigerant loop, the heat exchanger comprising at least a second refrigerant circuit consisting of the second fluid inlet channel of the connecting device, of the fluid inlet portion of the second collecting chamber of the first refrigerant header, which is fluidically connected to the tubes of the second set, of the tubes of the second set, of the second collecting chamber of the second refrigerant header, which is fluidically connected to the tubes of the second set, of the fluid outlet portion of the second collecting chamber of the first header, which is fluidically connected to the tubes of the second set and of the second fluid outlet channel, the second fluid inlet channel being configured to be fluidically connected to the first portion of the refrigerant loop and the second fluid outlet channel being configured to be fluidically connected to the second portion of the refrigerant loop, the tubes of the first set and the tubes of the second set being fluidically distinct from one another.
It will be appreciated that the refrigerant circuits as have just been described correspond to a heat exchanger according to the first embodiment, for which the tubes of the first set and the tubes of the second set have different lengths of extension. As the circulation of the refrigerant in the first circuit and the circulation of the refrigerant in the second circuit are in opposite directions, these circulations allow better distribution of the temperature gradient of the refrigerant over the heat-exchange surface. The temperature of the heat-exchange surface is thus more uniform, so that the formation of frost on the exchange surface of the heat exchanger is limited.
According to an alternative feature, the heat exchanger comprises at least a first refrigerant circuit consisting of the first fluid inlet channel of the connecting device, of the fluid inlet portion of the first collecting chamber of the first refrigerant header, which is fluidically connected to the tubes of the first set, of the tubes of the first set, of the second collecting chamber of the second header, which is fluidically connected to the tubes of the first set, of the fluid outlet portion of the first collecting chamber of the first refrigerant header, which is fluidically connected to the tubes of the first set and of the first fluid outlet channel, the first fluid inlet channel being configured to be fluidically connected to a first portion of the refrigerant loop and the first fluid outlet channel being configured to be fluidically connected to a second portion of the refrigerant loop, the heat exchanger comprising at least a second refrigerant circuit consisting of the second fluid inlet channel of the connecting device, of the fluid inlet portion of the second collecting chamber of the first refrigerant header, which is fluidically connected to the tubes of the second set, of the tubes of the second set, of the first collecting chamber of the second refrigerant header, which is fluidically connected to the tubes of the second set, of the fluid outlet portion of the second collecting chamber of the first header, which is fluidically connected to the tubes of the second set and of the second fluid outlet channel, the second fluid inlet channel being configured to be fluidically connected to the first portion of the refrigerant loop and the second fluid outlet channel being configured to be fluidically connected to the second portion of the refrigerant loop, the tubes of the first set and the tubes of the second set being fluidically distinct from one another.
It will be appreciated that the refrigerant circuits as have just been described correspond to a heat exchanger according to the second embodiment, for which the tubes of the first set and the tubes of the second set have the same lengths of extension.
According to one feature of the invention, the fluid outlet portion of the first collecting chamber and the fluid inlet portion of the second collecting chamber are separated from the fluid outlet portion of the second collecting chamber and from the fluid inlet portion of the first collecting chamber by a fluidtight partition.
This separation by means of the fluidtight partition allows two distinct fluid circuits to be kept separate within the same header. A first of these circuits, for example the refrigerant circuit having an inlet portion in the second collecting chamber and an outlet portion in the first collecting chamber, is thus distinct from a second refrigerant circuit, for example the circuit having an inlet portion in the first collecting chamber and an outlet portion in the second collecting chamber. Each circuit thus has its own fluid inlet and outlet portions, the fluidtight partition allowing these two circuits to cohabit the same header. In this way, all of the fluid inlet and outlet portions are grouped together at the one same longitudinal end of the heat-exchange surface.
According to one feature of the invention, the fluid outlet portion of the first collecting chamber and the fluid inlet portion of the second collecting chamber are separated from the fluid outlet portion of the second collecting chamber and from the fluid inlet portion of the first collecting chamber by a fluidtight partition.
Further features, details and advantages of the invention will become more clearly apparent from reading the following description, and from studying exemplary embodiments given by way of non-limiting illustration, with reference to the appended drawings, in which:
The features, variants and different embodiments of the invention may be combined with one another, in various combinations, provided that they are not mutually incompatible or mutually exclusive. In particular, it is possible to envisage variants of the invention that comprise only a selection of features described below, independently of the other features described, if this selection of features is sufficient to confer a technical advantage and/or to differentiate the invention from the prior art.
In the figures, elements that are common to multiple figures retain the same reference.
In the following detailed description, the terms “longitudinal”, “transverse” and “vertical” refer to the orientation of the heat exchanger according to the invention. A longitudinal direction corresponds to a main direction of elongation of the tubes which are configured to channel the refrigerant, this longitudinal direction being parallel to a longitudinal axis L of a coordinates system L, V, T illustrated in the figures. A vertical direction corresponds to a direction of stacking of these tubes, this vertical direction being parallel to a vertical axis V of the coordinates system L, V, T, and this vertical axis V being perpendicular to the longitudinal axis L. Finally, a transverse direction corresponds to a direction parallel to a transverse axis T of the coordinates system L, V, T, this transverse axis T being perpendicular to the longitudinal axis L and to the vertical axis V.
In addition, in the present description, the term “refrigerant” may refer to any heat-transfer, cooling, dielectric, or two-phase fluid or liquid, provided that this fluid or liquid has the effect of cooling or heating the flow of air passing through the heat-exchange surface of a heat exchanger.
The heat exchanger 1 comprises a heat-exchange surface 2 which is intended to be passed through by an air flow 100 flowing substantially perpendicular to the plane of elongation in which the heat-exchange surface is mainly inscribed. The heat exchanger 1 also comprises a first refrigerant header 3 arranged at a first longitudinal end 21 of the heat-exchange surface 2, and a second refrigerant header 4 arranged at a second longitudinal end 22 of the heat-exchange surface 2. It will thus be appreciated that the heat-exchange surface 2 is delimited longitudinally by, on the one hand, the first refrigerant header 3 and, on the other hand, the second refrigerant header 4.
The first refrigerant header 3 and the second refrigerant header 4 have, at their respective vertical ends, partitions which have not been depicted in this figure. These partitions ensure the fluid tightness of the refrigerant headers 3 and 4.
The heat-exchange surface 2 comprises tubes 5 which are configured to channel the refrigerant from one header to the other. These tubes 5 thus extend longitudinally between the first refrigerant header 3 and the second refrigerant header 4, being stacked in a direction of stacking E which corresponds to a vertical direction of the heat exchanger 1.
The tubes 5 are distributed between two sets of tubes, forming a first set 5A and a second set 5B, each set of tubes being fluidically distinct from the other set of tubes. In other words, the refrigerant circulating from the inlet to the outlet of the heat exchanger within the tubes of the first set of tubes is not able to circulate within the tubes of the second set of tubes.
According to a first embodiment, in which the tubes of the first set 5A have smaller lengths of extension than the tubes of the second set 5B, these tubes of the first set 5A open at a first of their longitudinal ends into the first collecting chamber 30 of the first refrigerant header 3, and at a second of their longitudinal ends into the first collecting chamber 40 of the second refrigerant header 4. The tubes of the second set 5B open at a first of their longitudinal ends into the second collecting chamber 31 of the first refrigerant header 3, and at a second of their longitudinal ends into the second collecting chamber 41 of the second header 4.
According to a second embodiment, in which the tubes 5 all have the same lengths of extension, the tubes of the first set 5A open at a first of their longitudinal ends into the first collecting chamber 30 of the first refrigerant header 3, and at a second of their longitudinal ends into the second collecting chamber 41 of the second refrigerant header 4. The tubes of the second set 5B open at a first of their longitudinal ends into the second collecting chamber 31 of the first refrigerant header 3, and at a second of their longitudinal ends into the first collecting chamber 40 of the second header 4.
What is meant by opening into is that the tubes of the first set 5A have, at their two longitudinal ends, free ends that are able to allow the refrigerant to pass, these free ends being arranged respectively in the first collecting chamber 30 of the first refrigerant header 3 and in the first collecting chamber 40 or the second collecting chamber 41 of the second refrigerant header 4, depending on the embodiment. In the same way, the tubes of the second set 5B have, at their two longitudinal ends, free ends that are arranged respectively in the second collecting chamber 31 of the first refrigerant header 3 and in the first collecting chamber 40 or the second collecting chamber 41 of the second refrigerant header 4, depending on the embodiment.
According to the invention, at least one refrigerant header is divided into two collecting chambers. In this embodiment, this at least one refrigerant header will be considered to correspond to the first refrigerant header 3. This at least one refrigerant header may, however, and indifferently, be located at a first longitudinal end 21 of the heat-exchange surface 2 or at a second longitudinal end 22 of the heat-exchange surface 2.
Without departing from the context of the invention, provision may be made for the two headers to have such a partitioning into two collecting chambers, and provision may notably be made for the two headers to have equivalent configurations, one being the mirror image of the other about the heat-exchange surface.
In the example illustrated, the first refrigerant header 3 is divided into two collecting chambers 30 and 31, namely a first collecting chamber 30 and a second collecting chamber 31, and the second refrigerant header 4 is likewise divided into two collecting chambers 40 and 41, namely a first collecting chamber 40 and a second collecting chamber 41.
In the vicinity of the first longitudinal end 21 of the heat-exchange surface 2, the first collecting chamber 30 and the second collecting chamber 31 of the first refrigerant header 3 are aligned in a longitudinal direction, with the first collecting chamber 30 being situated between the heat-exchange surface 2 and the second collecting chamber 31. Similarly, in the vicinity of the second longitudinal end 22 of the heat-exchange surface 2, the first collecting chamber 40 and the second collecting chamber 41 of the second refrigerant header 4 are aligned in a longitudinal direction, with the first collecting chamber 40 being situated between the heat-exchange surface 2 and the second collecting chamber 41.
The first collecting chamber 30 of the first refrigerant header 3 comprises a fluid inlet portion 300 and a fluid outlet portion 301. Each of these portions of the first collecting chamber is equipped with a fluidic-connection end-piece for connection to the refrigerant loop so that this refrigerant can be supplied and removed. A first inlet end-piece and a first outlet end-piece, which form connecting means 83 as will be described in greater detail later, are thus arranged in the first header so as to open into the first collecting chamber and have a free end opening to the outside of the heat exchanger. As visible in
The second collecting chamber 31 of the first refrigerant header 3 comprises a fluid inlet portion 310 and a fluid outlet portion 311 which may also be attached to an end-piece to facilitate connection to the refrigerant loop, or alternatively may merely be equipped with an orifice providing fluidic communication between the second collecting chamber and the refrigerant loop.
The fluid inlet portion 300 and the fluid inlet portion 310 correspond to the portions via which the refrigerant enters the heat exchanger 1, whereas the fluid outlet portion 301 and the fluid outlet portion 311 correspond to the portions via which the refrigerant is removed from the heat exchanger 1. In other words, the fluid enters the heat exchanger via two distinct inlet portions, the portion of fluid entering via the fluid inlet portion associated with the first collecting chamber or, respectively, with the second collecting chamber, being intended to circulate in the heat-exchange surface, and notably through the first set of tubes or, respectively, the second set of tubes, as will be described hereinafter, in order to return toward the fluid outlet portion associated with this first collecting chamber or, respectively, this second collecting chamber, and leave the heat exchanger.
As visible in
According to the invention, the heat exchanger 1 has a connecting device 68 associated with the first refrigerant header 3. This connecting device 68 comprises a refrigerant inlet duct 6 and a refrigerant outlet duct 7. The refrigerant inlet duct 6 is divided into a first fluid inlet channel 60 and a second fluid inlet channel 61, whereas the fluid outlet duct 7 makes the connection between a first fluid outlet channel 70 and a second fluid outlet channel 71.
More particularly, and as will be described in greater detail with reference to
The first fluid inlet channel 60 is coupled to the fluid inlet portion 300 of the first collecting chamber 30, and the second fluid inlet channel 61 is coupled to the fluid inlet portion 310 of the second collecting chamber 31. The first fluid outlet channel 70 is coupled to the fluid outlet portion 301 of the first collecting chamber 30, and the second fluid outlet channel 71 is coupled to the fluid outlet portion 311 of the second collecting chamber 31. As illustrated here, the first fluid inlet channel 60 and the second fluid outlet channel 71 are coupled to their corresponding collecting-chamber portion via a tubular element 82.
According to the first embodiment depicted here, the tubes of the first set 5A have a length of main extension of a value smaller than that of the length of main extension of the tubes of the second set 5B. These lengths of main extension correspond to the dimension of the tubes 5 between their first longitudinal ends and their second longitudinal ends. It will thus be appreciated that each of the tubes of the first set 5A is shorter than each of the tubes of the second set 5B, and conversely that each of the tubes of the second set 5B is longer than each of the tubes of the first set 5A. Conversely, according to the second embodiment visible in
The tubes 5 are stacked in the direction of stacking E as an alternation of tubes of the first set 5A alternating with tubes of the second set 5B. This alternation is manifested in the repetition of a layout pattern made up of one tube of the first set 5A and one tube of the second set 5B, this layout pattern being repeated in the direction of stacking E. In the example illustrated, the alternation of one tube of the first set 5A alternating with one tube of the second set 5B extends from one vertical end of the heat-exchange surface 2 to the other.
The first refrigerant header 3 has, at a first of its longitudinal ends, an outer wall 33 situated some distance from the heat-exchange surface 2, and at a second of its longitudinal ends, a sealing wall 34. These walls 33 and 34 extend in a substantially vertical direction, namely in the direction of stacking E of the tubes 5. The sealing wall 34 forms a surface of contact between the heat-exchange surface and the first header, and comprises slots 340 arranged in parallel with one another along the vertical direction, each slot being dimensioned to allow the passage of either, and indifferently, a tube of the first set 5A or a tube of the second set 5B.
The first collecting chamber 30 and the second collecting chamber 31 are separated by a dividing wall 32. This dividing wall 32 has a first face and a second face, the first face facing into the first collecting chamber 30 while the second face faces into the second collecting chamber 31. The dividing wall 32 has openings 320 able to allow the tubes of the second set 5B to pass through them, so that these tubes open into the second collecting chamber 30.
In this arrangement, the heat-exchange surface 2, the sealing wall 34, the first collecting chamber 30, the dividing wall 32 and the second collecting chamber 31 are aligned in a longitudinal direction, which corresponds to the direction of extension of the tubes 5.
More particularly, the sealing wall 34 comprises first slots which are configured to receive the tubes of the first set 5A, which thus pass through the sealing wall to open into the first collecting chamber 30. The sealing wall 34 also comprises second slots configured to receive the tubes of the second set 5B. These tubes of the second set 5B, which are longer than the tubes of the first set 5A, also pass through the dividing wall 32 which has openings 320 able to receive them. The tubes of the second set 5B can therefore pass through the first sealing wall 34, the first collecting chamber 30 and the dividing wall 32, in order to reach the second collecting chamber 31 into which they open. It will be appreciated that, in order to allow the tubes of the second set 5B to pass through the dividing wall 32 and the sealing wall 34, the openings 320 of the dividing wall 32 face the second slots of the sealing wall 34.
The openings 320 and the slots 340 are formed at regular intervals in the dividing wall 32 and in the sealing wall 34, respectively. Such openings in the dividing wall 32 and sealing wall 34 form cylinders to accommodate the tubes 5. In the example illustrated, these accommodating cylinders all have a similar shape, the exterior profile of the tubes being the same regardless as to whether they form part of the first set of tubes or of the second set of tubes. Additionally, provision may be made for the exterior profile of the tubes of the first set to differ from the exterior profile of the tubes of the second set, and for the slots and the openings to have profiles that may vary for collaborating with their respective tubes. In that way, poka-yoke means are formed to ensure that a tube of the first set cannot be fitted in the place intended for a tube of the second set.
The first refrigerant header 3 further comprises a fluidtight partition 9 which extends all the way through the dividing wall 32, from the outer wall 33 of the first refrigerant header 3 to the sealing wall 34 of this first refrigerant header 3. This dividing partition 9 is parallel to the longitudinal direction of the heat exchanger 1 and perpendicular to the dividing wall 32, to the outer wall 33 and to the sealing wall 34.
This fluidtight partition 9 acts as a divider separating, on the one hand, an assembly formed of the fluid outlet portion 301 of the first collecting chamber 30 and of the fluid inlet portion 310 of the second collecting chamber 31 from, on the other hand, an assembly formed of the fluid outlet portion 311 of the second collecting chamber 31 and of the fluid inlet portion 300 of the first collecting chamber 30. The fluidtight partition 9 has a first face 91 and a second face 92 making it possible to distinguish the tubes of the first set 5A, which are arranged facing this first face 91, from the tubes of the first set 5A which are arranged facing this second face 92. In the same way, the fluidtight partition 9 separates the tubes of the second set 5B, which are arranged facing the first face 91, from the tubes of the second set 5B, which are arranged facing the second face 92.
In the example illustrated, the housing that forms the body of the connection fitting has, on one transverse end face, a connection face 84. This connection face 84 is pierced with two connection orifices 63, 73 to which the fluid inlet duct 6 and the fluid outlet duct 7 are respectively coupled.
The body 80 of the connection fitting 8 also has, on a first vertical end face, perpendicular to the connection face 84, a connection face 86 to which will be coupled the tubular elements 82 which will be described hereinafter and which provide the connection between the body of the connection fitting and collecting chambers of the first header which is situated some distance from the body of the connection fitting.
Alternatively, without departing from the context of the invention, provision may be made for the fluid inlet duct and fluid outlet duct connection orifices to be arranged on a face other than the transverse end face illustrated, or for them to be distributed over two distinct faces and notably over the two opposite transverse end faces of the housing, and provision may be made for the tubular elements 82 to be coupled on a face other than the first vertical end face. It should however be noted that the connection fitting body housing face to which the tubular elements are attached is substantially perpendicular to the connection face.
The longitudinal end face 85 pressed against the header, and more particularly against the outer wall 33 of the first header 3, has a concave shape that complements a convex shape of the outer wall 33 of the first header 3. This complementarity of the complementary face 85 and of the outer wall 33 makes for easy assembly of the two elements and holds the one relative to the other.
According to the invention, the connection fitting fixed to the first header and forming part of the connecting device 68 is such that various channels are formed therein, so that the fluid inlet duct 6 communicating with an inlet connection orifice 63 formed in the connection face 84 is divided into two fluid inlet channels extending separately in the connection fitting from this inlet connection orifice 63 with the first fluid inlet channel 60 being separate from the second fluid inlet channel 61. Similarly, two fluid outlet channels extend separately in the housing until they meet at the outlet connection orifice 73 associated with the fluid outlet duct 7, so that this fluid outlet duct provides the connection between the first fluid outlet channel 70 and the second fluid outlet channel 71.
The fluid inlet channels 60, 61 arranged in the body 80 of the connection fitting 8 extend perpendicular to one another from the inlet connection orifice 63. In the same way, the fluid outlet channels 70, 71 arranged in the body 80 of the connection fitting 8 extend perpendicular to one another from the outlet connection orifice 73. The result of this is that the inlet channels open onto faces of the housing that forms the body 80 of the connection fitting that are separate from and perpendicular to one another, and that, similarly, the outlet channels open onto faces of the housing that forms the body of the connection fitting that are separate from and perpendicular to one another.
The inlet and outlet connection orifices 63, 73 to which the inlet and outlet ducts 6, 7 are coupled, as well as the inlet channels and the outlet channels, may notably be created in the thickness of the housing that forms the connection fitting by using a machining operation, for example drilling or boring. Alternatively, the housing and the channels produced therein may be created using additive manufacturing.
At their free end, which is to say at their opposite end from the corresponding connection orifice, the fluid inlet and outlet channels 60, 61, 70 and 71 may be coupled to the first refrigerant header 3 in various different ways, and notably may be directly coupled by welding or brazing the connection fitting to the first header, or else may be coupled by means of a tubular element as mentioned previously. More particularly, the connection fitting is fixed to the header in such a way that two channels are positioned directly facing orifices, which have not been depicted in
The first fluid inlet channel 60 and the second fluid outlet channel 71 are themselves coupled to orifices formed in the first header 3, via the tubular elements 82. These tubular elements 82 may notably adopt the form of rigid bent tubes able to channel the refrigerant. The tubular elements 82 are advantageously arranged in the continuation of the plane of elongation of the heat-exchange surface 2 so that the heat exchanger 1 has a smaller bulk.
Irrespective of whether the channels are coupled to the first header 3 directly or indirectly via the tubular elements 82, provision may be made for connecting means 83 for ensuring fluid tightness at the interface between the channels and the collecting chambers formed in the first header. These connecting means 83 may, for example, be end-pieces 830 which may or may not be equipped with flanges 831.
The end-pieces 830 may notably be attached components push-fitted onto the fluid inlet or outlet channels, or the associated tubular elements, and the dimensions of which allow them to pass through the orifice made in the outer surface 33 of the first header, and to open into the collecting chamber with which the corresponding channel is to communicate fluidically.
As mentioned previously,
As mentioned previously, the connecting device 68 comprises a first fluid inlet channel 60, a second fluid inlet channel 61, a first fluid outlet channel 70 and a second fluid outlet channel 71. Each of these channels 60, 61, 70 and 71 is coupled to one of the portions 300, 301, 310 and 311 of the collecting chambers 30 and 31, as follows: the first fluid inlet channel 60 is coupled to the fluid inlet portion 300 of the first collecting chamber 30, the first fluid outlet channel 70 is coupled to the fluid outlet portion 301 of the first collecting chamber 30, the second fluid inlet channel 61 is coupled to the fluid inlet portion 310 of the second collecting chamber 31, and the second fluid outlet channel 71 is coupled to the fluid outlet portion 311 of the second collecting chamber 31.
What is meant by “coupled” is that each fluid inlet or outlet channel 60, 61, 70 and 71 has connecting means 83 and, more particularly, an end-piece 830 and/or a flange 831. End-pieces 830 and flanges 831 thus form means suited to the fluidtight connection of the fluid inlet or outlet channels 60, 61, 70 and 71 to which they are fitted to the fluid inlet or outlet portions 300, 301, 310 and 311 to which they are coupled.
To this end, the end-pieces 830 may for example be forcibly driven into the outer wall 33 of the refrigerant header 3, thus ensuring the fluid tightness of the refrigerant loop 10.
One of the end-pieces 830 may equally be a rigid end-piece and therefore act as a positioning reference when assembling the connection fitting 8 to the refrigerant header 3. In the same way, the flanges 831 may act as end stops during assembly, thus allowing this connection fitting 8 to be positioned in contact with the refrigerant header 3 more easily.
Certain end-pieces 830 may have a tapering shape, as is the case of the fluid inlet channel 60 and fluid outlet channel 70 in the embodiment illustrated in the present figure. This tapering shape notably allows the channels to pass through the second collecting chamber 31 and the dividing wall 32 without being in contact with the tubes of the second set 5B, so as to open into the first collecting chamber 30 into which the tubes of the first set 5A also open.
The fluidtight partition 9 makes it possible to achieve a physical and fluidic separation between, on the one hand, the fluid inlet portion 300 of the first collecting chamber 30, the first fluid inlet channel 60, the fluid outlet portion 311 of the second collecting chamber 31 and the second fluid outlet channel 71 and, on the other hand, the fluid outlet portion 301 of the first collecting chamber 30, the first fluid outlet channel 70, the fluid inlet portion 310 of the second collecting chamber 31 and the second fluid inlet channel 61.
According to the embodiment depicted in
The present invention also intends to cover embodiments in which the collecting chambers are separate, which means to say not distinct chambers within the one same header. These could notably be two collecting chambers positioned one next to the other in a transverse direction. A body 80 of a connection fitting 8 could for example be fixed to a first collecting chamber such that the second fluid inlet channel 61 and the first fluid outlet channel 70 are coupled directly to this first collecting chamber, namely without the need for tubular elements 82. The connection fitting 8 would then comprise a first fluid inlet channel 60 and a second fluid outlet channel 71, themselves equipped with tubular elements 82, these tubular elements 82 being coupled to the second collecting chamber arranged transversely next to the first collecting chamber.
This figure more particularly reveals that the first collecting chamber 30 of the first refrigerant header 3 has the inlet portion 300 coupled to the first fluid inlet channel 60, and the outlet portion 302 coupled to the first fluid outlet channel 70. It also reveals that the second collecting chamber 31 of the first refrigerant header 3 on the other hand has the inlet portion 310 coupled to the second fluid inlet channel 61, and the outlet portion 311 coupled to the second fluid outlet channel 71.
Within the refrigerant loop 10, the fluid inlet portion 300 of the first collecting chamber 30 and the fluid inlet portion 310 of the second collecting chamber 31 are therefore fluidically connected via the connecting device 68. Specifically, the fluid inlet portions 300 and 310 are respectively coupled to the first fluid inlet channel 60 and to the second fluid inlet channel 61, thus allowing the heat-exchange surface 2 to be supplied with refrigerant via the fluid inlet duct 6.
In this refrigerant loop 10, the outlet portion 301 of the first collecting chamber 30 and the outlet portion 311 of the second collecting chamber 31 are likewise fluidically connected; they are respectively coupled to the first fluid outlet channel 70 and to the second fluid outlet channel 71, allowing the refrigerant leaving the heat-exchange surface 2 to be removed via the fluid outlet duct 7.
The heat exchanger 1 comprises at least a first refrigerant circuit 50A consisting of the first fluid inlet channel 60 of the connecting device 68, of the fluid inlet portion 300 of the first collecting chamber 30 of the first refrigerant header 3, which is fluidically connected to the tubes of the first set 5A, of the tubes of the first set 5A, of the first collecting chamber 40 of the second header 4, which is fluidically connected to the tubes of the first set 5A, of the fluid outlet portion 301 of the first collecting chamber 30 of the first refrigerant header 3, which is fluidically connected to the tubes of the first set 5A and of the first fluid outlet channel 70.
The first fluid inlet channel 60 is configured to be fluidically connected to a first portion of the refrigerant loop, and the first fluid outlet channel 70 is configured to be fluidically connected to a second portion of the refrigerant loop.
The heat exchanger 1 moreover comprises at least a second refrigerant circuit 50B consisting of the second fluid inlet channel 61 of the connecting device 68, of the fluid inlet portion 310 of the second collecting chamber 31 of the first refrigerant header 3, which is fluidically connected to the tubes of the second set 5B, of the tubes of the second set 5B, of the second collecting chamber 41 of the second refrigerant header 4, which is fluidically connected to the tubes of the second set 5B, of the fluid outlet portion 311 of the second collecting chamber 31 of the first header 3, which is fluidically connected to the tubes of the second set 5B and of the second fluid outlet channel 71.
The second fluid inlet channel 61 is configured to be fluidically connected to the first portion of the refrigerant loop, and the second fluid outlet channel 71 is configured to be fluidically connected to the second portion of the refrigerant loop.
Because the collecting chambers within the one same header are fluidically separate from one another and the tubes of the first set 5A and the tubes of the second set 5B are likewise separate from one another, it will be appreciated that the portion of refrigerant that flows in the first refrigerant circuit 50A can circulate in the heat exchanger independently of the portion of refrigerant that flows in the second refrigerant circuit 50B, before being recombined into a common flow at the outlet of the heat exchanger.
Such an arrangement notably makes it possible to make the refrigerant circulate within the exchange surface 2 and, by extension, within the heat exchanger 1, in two separate and opposite directions of circulation in adjacent tubes.
When the refrigerant follows the first refrigerant circuit 50A, the refrigerant is conveyed toward the heat exchanger 1 by the fluid inlet duct 6 arranged in the connecting device 68. It circulates in the first inlet channel 60 then through the tubes of the first set 5A which are positioned facing the first face 91 of the fluidtight partition 9, from the inlet portion 300 of the first collecting chamber 30 of the first refrigerant header 3 to the first collecting chamber 40 of the second refrigerant header 4. It then enters the tubes of the first set 5A, which are positioned facing the second face 92 of the fluidtight partition 9, in order to reach as far as the outlet portion 301 of the first collecting chamber 30 of the first refrigerant header 3, where it passes along the first fluid outlet channel 70 in order to reach the fluid outlet duct 7.
The second refrigerant circuit 50B corresponds to circulation of the refrigerant from the fluid inlet duct 6 arranged in the connecting device 68. The refrigerant circulates through the second inlet channel 61 then through the tubes of the second set 5B which are positioned facing the second face 92 of the fluidtight partition 9, from the inlet portion 310 of the second collecting chamber 31 of the first header 3 to the second collecting chamber 41 of the second refrigerant header 4. The refrigerant then circulates through the tubes of the second set 5B positioned facing the first face 91 of the fluidtight partition 9 in order to be conveyed as far as the outlet portion 311 of the second collecting chamber 31 of the first refrigerant header 3, where it passes along the second fluid outlet channel 71 in order to reach the fluid outlet duct 7.
As far as the tubes positioned in that part of the heat-exchange surface that faces the first face 91 of the fluidtight partition 9 are concerned, there is thus one portion of the flow of refrigerant that circulates in a first direction, from the first header to the second header, through the tubes of the second set of tubes 5B, while the other portion of the flow of refrigerant circulates in the other direction, from the second header to the first header, through the tubes of the first set of tubes 5A. Because the two types of tubes are arranged so that they alternate in the stack of tubes of the heat-exchange surface, this then ensures that the refrigerant circulating in two adjacent tubes circulates in opposite directions.
It should be noted that the refrigerant is intended to exchange heat energy with an air flow passing through the heat-exchange surface. The temperature of the refrigerant as it enters the heat exchanger differs from its temperature as it exits this exchanger, and in particular the temperature decreases between entering and exiting when the heat exchanger is operating in evaporator mode. The cross-flow circulation that has just been described allows a portion of refrigerant close to an inlet portion, and therefore at a first temperature value, to circulate side-by-side with a portion of refrigerant close to an outlet portion and therefore at a second temperature value.
These two directions of circulation of the refrigerant within the heat-exchange surface 2 make it possible to achieve better distribution of the temperature within this surface, and this contributes to preventing the formation of frost by avoiding significant temperature gradients from one zone of the heat-exchange surface to another and the risk that cold zones thus generated will contribute to the formation of frost if the moisture in the air has already condensed to form droplets on the surface of the heat exchanger.
According to this second embodiment, the heat exchanger 1 comprises at least a first refrigerant circuit 50A consisting of the first fluid inlet channel 60 of the connecting device 68, of the fluid inlet portion 300 of the first collecting chamber 30 of the first refrigerant header 3, which is fluidically connected to the tubes of the first set 5A, of the tubes of the first set 5A, of the second collecting chamber 41 of the second header 4, which is fluidically connected to the tubes of the first set 5A, of the fluid outlet portion 301 of the first collecting chamber 30 of the first refrigerant header 3, which is fluidically connected to the tubes of the first set 5A and of the first fluid outlet channel 70.
The heat exchanger 1 moreover comprises at least a second refrigerant circuit 50B consisting of the second fluid inlet channel 61 of the connecting device 68, of the fluid inlet portion 310 of the second collecting chamber 31 of the first refrigerant header 3, which is fluidically connected to the tubes of the second set 5B, of the tubes of the second set 5B, of the first collecting chamber 40 of the second refrigerant header 4, which is fluidically connected to the tubes of the second set 5B, of the fluid outlet portion 311 of the second collecting chamber 31 of the first header 3, which is fluidically connected to the tubes of the second set 5B and of the second fluid outlet channel 71.
When the refrigerant follows the first refrigerant circuit 50A, the refrigerant is conveyed toward the heat exchanger 1 by the fluid inlet duct 6 arranged in the connecting device 68. It circulates in the first inlet channel 60 then through the tubes of the first set 5A which are positioned facing the first face 91 of the fluidtight partition 9, from the inlet portion 300 of the first collecting chamber 30 of the first refrigerant header 3 to the second collecting chamber 41 of the second refrigerant header 4. It then enters the tubes of the first set 5A, which are positioned facing the second face 92 of the fluidtight partition 9, in order to reach as far as the outlet portion 301 of the first collecting chamber 30 of the first refrigerant header 3, where it passes along the first fluid outlet channel 70 in order to reach the fluid outlet duct 7.
The second refrigerant circuit 50B corresponds to circulation of the refrigerant from the fluid inlet duct 6 arranged in the connecting device 68. The refrigerant circulates through the second inlet channel 61 then through the tubes of the second set 5B which are positioned facing the second face 92 of the fluidtight partition 9, from the inlet portion 310 of the second collecting chamber 31 of the first header 3 to the first collecting chamber 40 of the second refrigerant header 4. The refrigerant then circulates through the tubes of the second set 5B positioned facing the first face 91 of the fluidtight partition 9 in order to be conveyed as far as the outlet portion 311 of the second collecting chamber 31 of the first refrigerant header 3, where it passes along the second fluid outlet channel 71 in order to reach the fluid outlet duct 7.
As far as the tubes positioned in that part of the heat-exchange surface that faces the first face 91 of the fluidtight partition 9 are concerned, there is thus one portion of the flow of refrigerant that circulates in a first direction, from the first header to the second header, through the tubes of the second set of tubes 5B, while the other portion of the flow of refrigerant circulates in the other direction, from the second header to the first header, through the tubes of the first set of tubes 5A. Because the two types of tubes are arranged so that they alternate in the stack of tubes of the heat-exchange surface, this then ensures that the refrigerant circulating in two adjacent tubes circulates in opposite directions.
The present invention thus proposes a heat exchanger included in a refrigerant loop which exchanger is intended to limit the formation of frost on this heat exchanger while at the same time having a small bulk, having tubes of two sets that are stacked in the one same plane of the heat-exchange surface, headers that comprise several collecting chambers aligned in the continuation of this plane of the heat-exchange surface, and a connecting device arranged in the continuation of the collecting chambers and of the heat-exchange surface.
However, the present invention is not limited to the means and configurations described and illustrated herein and it also extends to all equivalent means and configurations and to any technically functional combination of such means.
| Number | Date | Country | Kind |
|---|---|---|---|
| FR2109223 | Sep 2021 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/073520 | 8/23/2022 | WO |
