WO2019073139A1

WO2019073139A1 - Heat exchanger with device for blocking off circulation pipes for a gas that is to be cooled

Info

Publication number: WO2019073139A1
Application number: PCT/FR2018/052370
Authority: WO
Inventors: Alan Day; Florian SEGUIN
Original assignee: Valeo Systemes Thermiques
Priority date: 2017-10-13
Filing date: 2018-09-26
Publication date: 2019-04-18
Also published as: FR3072453A1; FR3072453B1

Abstract

The invention relates to a heat exchanger (1) comprising a body (4) comprising a bundle of pipes (5) for the circulation of a gas that is to be cooled, an outlet header (2) into which a mouth (6) of each pipe (5) opens and a pipe blocking-off device (3), characterized in that the blocking-off device (3) comprises at least one flap (10) mounted with the ability to pivot between a closed position in which the flap (10) closes of at least one mouth (6) of a pipe (5) and an open position, the blocking-off device (3) being configured to block off a predefined number of mouths (6), less than the total number of mouths (6) of pipes (5) opening into the header (2).

Description

Heat exchanger with shutter device for circulation ducts for a gas to be cooled

The description particularly relates to a heat exchanger, in particular a charge air cooler.

In the field of motor vehicles, the boost gas to the engine is cooled by a heat exchanger commonly referred to as a charge-gas cooler or charge air cooler (RAS). Some of these chillers, hereinafter referred to as air chokes, are cooled by air.

An air RAS comprises a bundle of charge gas circulation ducts and air passages for cooling air, which air passages are disposed between the charge gas circulation ducts. The charge gas circulation ducts open into an outlet manifold that is fluidly connected to the engine.

When the engine of a motor vehicle is in operation, a supercharging gas to be cooled circulates in the conduits and cooling air passes through the air passages. Under certain cooling air temperature conditions, a portion of the boost gas condenses, creating a build-up of water in the duct bundle and in the outlet manifold. At the acceleration of the vehicle, the water from the condensation starts in the vehicle engine and disrupts its operation.

In winter, when the engine of a motor vehicle is stopped, frost can form in the exchanger, clogging uncontrollably the recirculation gas ducts. When the engine is restarted, the recirculation gas for the engine intake is in deficit, which creates a malfunction of the engine. Then, the frost melts and turns into water that goes into the engine, disrupting its operation. The invention therefore aims to solve these problems by adapting the thermal performance of the heat exchanger to the need of the vehicle engine. If the engine is running at low flow, the heat exchanger requires less thermal performance.

The solution consists in closing off certain recirculating gas ducts and leaving others free, the number of these free ducts being chosen so as to obtain, on the one hand, the drainage of the condensation water for the low gas flow rates and on the other hand to move away as much as possible from the temperature and condensing pressure conditions of the circulating gas for the low gas flow rates.

The invention relates in particular to a heat exchanger comprising a body comprising a bundle of conduits for the circulation of a gas to be cooled, an outlet manifold into which a mouth of each conduit opens and a conduit closure device characterized in that the closure device comprises at least one flap pivotally mounted between a closed position in which the flap closes at least one mouth of a duct and an open position, the closure device being configured to close a predefined number of 'mouths, less than the total number of mouthpieces opening into the collector box.

According to one aspect of the invention, the closure device is a separate part of the manifold.

Thus, the closure device does not undergo the deformations of the manifold, for example caused by thermal expansion.

According to one aspect of the invention, the closure device comprises a plurality of flaps, each flap being able to close a duct mouth in its closed position.

According to one aspect of the invention, the shutter device comprises flap synchronization means.

The flap synchronization means allow movement synchronous flaps relative to each other and also to avoid vibrations.

According to one aspect of the invention, the flap synchronization means comprise a synchronization rod.

According to one aspect of the invention, the manifold comprises means for holding the closure device in the manifold.

According to one aspect of the invention, the means for holding the closure device comprise receiving tabs.

According to one aspect of the invention, the means for holding the closure device comprise abutment studs.

According to one aspect of the invention, the mechanical connection between the header and the closure device is elastic.

According to one aspect of the invention, the closure device comprises a frame comprising two longitudinal bars.

According to one aspect of the invention, the frame of the closure device is a molded part, plastic.

According to one aspect of the invention, each longitudinal bar comprises a leaf spring.

According to one aspect of the invention, the leaf spring is made of material with the longitudinal bar.

According to one aspect of the invention, the leaf spring is constrained against the means for holding the closure device in the header box.

According to one aspect of the invention, the closure device comprises resilient holding means adapted to maintain in the closed position the at least one flap when the flow rate of gas to be cooled is below a certain threshold.

According to one aspect of the invention, the closure device comprises prestressing means of the elastic holding means.

According to one aspect of the invention, the elastic holding means comprise a torsion spring comprising two branches and a winding, the angular spacing between the branches of the spring being reduced by a prestress angle with respect to its rest position.

The reduction of the angular difference between the branches of the spring prestresses the spring. Thus, below a certain gas flow threshold to be cooled, the torsion spring maintains in the closed position the at least one flap.

Above this threshold, the preload of the spring allows the progressive opening of the at least one flap when the boost gas flow increases gradually. Without this preload of the spring, the at least one shutter would open quickly and without control, which would no longer allow to adapt the heat performance of the exchanger according to the gas flow to be cooled.

According to one aspect of the invention, the torsion spring is located on one of the flaps.

According to one aspect of the invention, the stiffness of the spring is between 0.025 N.mm/° and 0.2 N.mm/°, preferably between 0.05 N.mm/° and 0.1 N.mm/ °.

According to one aspect of the invention, the torsion spring located on one of the shutters makes it possible to maintain elastically in the closed position all the shutters when the gas flow rate to be cooled is below a certain threshold.

According to one aspect of the invention, a torsion spring is located on each of the flaps.

According to one aspect of the invention, the cumulative stiffness of the springs is between 0.025 N.mm/° and 0.2 N.mm/°, preferably between 0.05 N.mm/° and 0.1 N.mm / °.

According to one aspect of the invention, the prestressing angle is between 3 ° and 15 °, preferably between 5 ° and 1 °.

According to one aspect of the invention, the shutter device is configured to close a predefined number of mouths between 50% and 90%, preferably between 50% and 60% of the total number of mouthpieces opening into the collector box.

Thus, proper drainage of water is always possible, even when the intake gas flow rate of the vehicle engine is low.

When the intake gas flow rate is higher than a certain threshold, the water resulting from the condensation of the supercharging gases in the exchanger is more easily evacuated.

Other characteristics and advantages of the invention will appear on reading the description which follows. This is purely illustrative and should be read in conjunction with the attached drawings in which:

FIG. 1 represents an exploded perspective view of a part of a heat exchanger comprising a closure device according to the invention,

FIG. 2 represents an exploded perspective view of a closure device according to the invention,

FIG. 3 illustrates a detail of the closure device,

FIG. 4 illustrates an embodiment of the elastic connection between the header and the closure device,

FIG. 5A represents a perspective view of a shutter,

FIG. 5B represents a sectional view of a shutter,

FIG. 6a illustrates an embodiment of an elastic holding means,

FIG. 6b illustrates the elastic holding means in a prestressed state,

FIG. 7 represents a collecting box,

FIG. 8 represents a sectional view of the portion of an exchanger illustrated in FIG. The following achievements are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each element mentioned in the context of an embodiment relates only to this same embodiment, or that features of this embodiment apply only to this embodiment.

In FIG. 1, the heat exchanger 1 comprises a header 2, a body 4 and a closure device 3.

The body comprises a bundle of conduits 5 for circulating a gas to cool. The duct bundle 5 is held by a manifold plate 8. The manifold plate 8 has a bottom 9 having holes for the passage of the ducts 5 and a peripheral groove 7 for fixing the manifold 2 to the body 4, for example by crimping. The ducts 5 each comprise a mouth 6 opening into the manifold 2.

The manifold 2 is a collection box for the outlet of the gas to be cooled.

The heat exchanger 1 also comprises a gas inlet header to be cooled which is not shown in FIG. 1 and into which each other end of the ducts 5 opens. Similarly, the inlet manifold can be crimped on the body 4 by another collector plate. Thus, a gas to be cooled can flow from the inlet manifold box to the outlet manifold 2, through the ducts 5.

The closure device 3 comprises at least one flap 10 pivotally mounted between a closed position in which the flap 10 closes at least one mouth 6 of a duct 5 and an open position, the closure device 3 being configured to seal a predefined number of mouths 6, less than the total number of mouths 6 of ducts 5 opening into the manifold 2.

The shutter device 3 is configured to close a predefined number of mouthpieces 6 between 50% and 90%, preferably between 50% and 60% of the total number of mouthpieces 6 of conduits 5 opening into the header 2.

For example, in Figure 1, the body 4 comprises a bundle of 14 ducts. The shutter device 3 comprises eight flaps 10 capable of closing eight mouthpieces 6 of ducts 5, that is to say about 57% of the total number of mouths 6 of the ducts 5 opening into the header 2.

The closure device 3 comprises flaps 10 pivotally mounted on a frame 35. The flaps 10 are able to close mouths 6. Each flap 10 can seal one or more mouths 6.

Preferably, the rotation of the flaps is synchronized, for example by means of a synchronization rod 30 as shown in FIG.

FIG. 2 illustrates in detail the closure device 3.

The shutter device 3 comprises a frame 35 which allows the pivoting mounting of flaps 10.

The frame 35 comprises two longitudinal bars 31 and transverse bars 32.

Advantageously, a transverse bar 32 is disposed on each side of each flap 10. This ensures a good seal when the flaps 1 1 are in the closed position and a good mechanical support of the frame 35.

The frame 35 is of substantially rectangular shape. The transverse end bars 32 form the two short sides of the frame 35. The longitudinal bars 31 form the two long sides of the frame 35.

The frame 35 is an example of the supporting structure for the shutters 10, other embodiments are possible such as a plate, an arch ...

The flaps 10 are pivotally mounted on the frame 35 of the closure device 3. The axis of rotation of a flap 10 is parallel to the bars transversal 32.

Preferably, the rotation of the shutters is synchronized. The shutter device 3 comprises means for synchronizing the flaps 10, for example a synchronization rod 30 as illustrated in FIG. 2.

The synchronizing rod 30 is in the form of a comb comprising teeth 38, each tooth 38 being able to be fixed to a flap 10.

The flaps 10 are pivotally mounted on the frame 35.

A flap 10 comprises two journals 14 forming an axis of rotation.

The frame includes housings 40 for the journals 14 of which Figure 3 shows a more detailed view.

The housings 40 are located on the longitudinal bars 31.

A housing 40 includes a groove 42 and a hole 41 which can be through or blind. The holes 41 as illustrated in Figures 2 and 3 are through.

A hole 41 is able to receive a journal 14.

The groove 42 slides the pin 14 from an edge 45 of a longitudinal bar 31 to the hole 41 associated therewith.

Advantageously, the flaps 10 are mounted on the closure device 3 from below the closure device. The underside of the closure device 3 is defined as the part which after assembly is in facing relation with the body 4. The top of the device is defined as the part which after assembly faces the manifold 2.

Thus, the flaps 10 are mounted so that they can not be projected into the manifold 2 by unhooking the frame 35.

FIG. 4 illustrates a slat spring 51 located on a longitudinal strip 31 of the frame 35 of the closure device 3, making it possible to provide an elastic mechanical connection between the manifold 2 and the closure device 3. The leaf spring 51 is preferably made of material with the longitudinal bar 31, that is to say made of the same material as the longitudinal bar 31.

The leaf spring 51 comprises a lamella 53 surmounted by a head 52, the head 52 being projecting on the side of the manifold with respect to the lamella 53.

The leaf spring 51 is an embodiment that provides an elastic mechanical connection between the manifold 2 and the closure device 3, as described below.

FIGS. 5A and 5B illustrate a shutter 10 of the shutter device 3.

The flap 10 comprises a blade 11 comprising a sealing face 12 and an outer face 13.

The closing face 12 is able to close one or more mouths 6 of ducts 5.

When the flap 10 is in the closed position, the shutter face 12 of the flap completely covers the surface of one or more mouths 6 of one or more ducts 5 so as to obstruct said mouth or mouths 6, thus preventing a gas to cool to exit the obstructed conduit (s) to enter the outlet manifold 2.

The flap 10 shown in FIGS. 5A and 5B is able to close a mouth 6 of a duct 5.

Preferably, the shutter face 1 1 of the shutter is substantially flat and lying in a general plane of extension P2.

The outer face 13 of the blade 10 is the face opposite to the sealing face 12.

The outer face 13 of the blade 10 is included in a general extension plane P1.

For example, the general extension plane P1 is parallel to the general extension plane P2 The flap 10 is provided with journals 14 in two of its ends. The journals 14 are located on the axis of rotation AA of the shutter 1 1.

The axis of rotation A-A is not included in the general extension plane P1.

Preferably the axis of rotation A-A is offset relative to the blade 1 January. The axis of rotation A-A and therefore the pins 14 are not located on the blade 1 1.

The flaps 10 may have a synchronous or asynchronous movement with respect to each other.

Preferably, the rotation of the shutters is synchronized. In this case, the shutter device 3 comprises means for synchronizing the shutters 10, for example a synchronization rod 30.

Thus, as illustrated in FIG. 5A, the flap 10 comprises fastening means 17 to allow the attachment of the synchronization means, for example a synchronization rod 30.

The fastening means 17 are preferably configured to allow the synchronization means, in particular the synchronizing rod 30, to snap onto all the flaps 10 in a substantially synchronous manner.

The closure device 3 advantageously comprises elastic holding means able to maintain the closed position of the at least one flap 10 when the gas flow rate to be cooled is below a certain threshold.

Below a certain threshold of gas flow to be cooled, the flap 10 is held in the closed position by elastic holding means. Beyond this threshold, the pane 10 opens.

For example, the elastic holding means 20 comprise a torsion spring 25 as illustrated in FIGS. 6a and 6b.

The torsion spring 25 comprises two branches 22, 23 and a winding 21. The flap 10 of Figure 5A comprises a claw 16 for maintaining a branch 23 of the spring 25 on the flap.

The winding 21 of the spring 25 may be arranged around a pin 14.

The other leg 22 of the spring 25 may be arranged on the frame 35 in a holding zone of the longitudinal bars 31 or transverse bars 32, or on a transverse bar 32.

So that the opening of the flaps 10 is progressive when the gas flow to be cooled increases gradually, the closure device 3 comprises biasing means 50 elastic holding means 20.

The resilient holding means comprises a torsion spring.

In its rest position, that is to say before the assembly of the spring 25 on the closure device 3, the branches 22 and 23 form an angular gap A2, for example 180 °.

One embodiment of the prestressing means 50 is illustrated in FIG. 5A.

The blade 10 comprises at one of its ends a beveled step 15.

The tapered step 15 comprises an inclined surface 18 making a predefined angle A1 with the extension plane P1 of the blade 10.

The beveled step 15 is intended to receive the branch 23 of the torsion spring 27.

Advantageously, the claw 16 is located on the beveled step 15.

When the torsion spring 25 is assembled on the shutter 10 in the closed position, the branch 23 rests on the inclined surface 18 of the beveled step 15 and is held by the claw 16. The branch 22 is disposed on the frame 35 in a zone maintaining the longitudinal bars 31 or transverse bars 32. The branch 22 may also be arranged on a transverse bar. The torsion spring 25 is prestressed. The predefined angle A1 is chosen so that the angular difference A2 between the branches 22 and 23 of the spring 25 is reduced by a non-zero prestress angle A3 when the flap 10 is in the closed position.

For example, as shown in Figure 6a, the angular gap A2 of the spring 25, in its rest position, is equal to 180 °.

The beveled step 15 makes a predefined angle A1 equal to 8 ° with the extension plane P1 of the blade 10.

When the spring 25 is assembled on the flap 10 and the flap 10 is in the closed position, the angular spacing A2 of the spring is reduced relative to its rest position by a prestressing angle equal to the predefined angle A2 which is equal to 8 °, that is to say that the angular difference A2 is equal to 172 °.

For a spring whose stiffness is between 0.025 N.mm/° and 0.2 N.mm/°, preferably between 0.05 N.mm/° and 0.1 N.mm/°, the angle of prestress A3 is advantageously between 3 ° and 15 °, preferably between 5 ° and 1 1 °, for example 8 °.

In Figure 6a, the spring 25 is in its rest position.

In Figure 6b, the spring 25 is assembled on the flap 10, the flap being in its closed position. The spring 25 is prestressed. The branch 23 of the spring 25 makes an angle A3 with respect to the position it would occupy in its rest position.

FIG. 7 illustrates an embodiment of the holding means 60 of the closure device 3 in the manifold 2.

The closure device 3 must be properly held against the body 4 of the heat exchanger 1 which comprises the bundle of ducts 5, in particular against the mouths 6 of the ducts 5, so that in the closed position, the shutter or shutters 1 1 correctly seal the mouths 6 of the ducts 5.

According to one embodiment, the closure device 3 is fixed on the body 4, for example by crimping, soldering or bonding to the plate collector 8.

According to another embodiment, the manifold 2 comprises holding means 60 of the closure device 3 in the manifold 2.

FIGS. 7 and 8 illustrate holding means 60 comprising receiving tabs 61 able to hold the closure device 3 in the manifold 2.

As can be seen in FIG. 8, the receiving tabs 61 of the manifold 2 form stops in the manifold 2 for the frame 35 of the closure device 3.

Advantageously, the leaf springs 51 of the longitudinal bars 31 of the frame 35 of the closure device 3, shown in FIG. 4, provide an elastic mechanical connection between the header box 2 and the closure device 3. Indeed, the leaf springs 51 of the longitudinal bars 31 of the frame 35 of the closure device 3 are in abutment with the receiving tabs 61 of the header 2.

The leaf springs 51 are constrained when the header is attached to the body 4 of the heat exchanger 1, for example when the header is crimped onto the flange 8.

This makes it possible to press the flaps 10 firmly against the mouths 6 of the tubes 5, in order to ensure a good tightness of the flaps 10 when they are in the closed position and to avoid vibrations, even if the mouths 6 of the tubes 5 are not coplanar. with the bottom 9 of the header plate 8, for example if the mouths 6 are protruding into the manifold 2. relative to the bottom 9 of the header plate 8.

The reception tabs 61 may be made of material with the manifold 2. For example, protuberances on the inner wall 63 of the manifold 2 form the welcome tabs 61.

Complementarily or alternatively, the holding means 60 may comprise abutment studs. The holding means 60 may be separate elements of the manifold 2. For example, abutment studs may be screwed, force-fitted or glued to the inner wall 63 of the manifold 2.

The closure device of the invention is adaptable to any heat exchanger reference. The body 4 of the exchanger is the body of a standard heat exchanger. The outlet manifold 2 may be a standard box, to which are added means for holding the closure device, for example abutment studs, or a specific manifold with the same dimensions as the standard box to allow a interchangeability.

Claims

1. Heat exchanger (1) comprising a body (4) comprising a bundle of conduits (5) for circulating a gas to be cooled, an outlet manifold (2) into which a mouth (6) of each conduit (5) opens ) and a shutter device (3) conduits characterized in that the closure device (3) comprises at least one flap (10) pivotally mounted between a closed position in which the flap (10) closes at least one mouthpiece (6) a duct (5) and an open position, the closure device (3) being configured to close a predefined number of mouths (6), less than the total number of mouths (6) of ducts ( 5) opening into the collecting box (2).

2. Heat exchanger (1) according to claim 1, characterized in that the closure device (3) comprises a plurality of flaps (10), each flap (10) being adapted to close a mouth (6) of duct (5). ) in its closed position.

3. Heat exchanger (1) according to the preceding claim, characterized in that the closure device (3) comprises means for synchronizing the flaps (10).

4. heat exchanger (1) according to any one of the preceding claims, characterized in that the manifold (2) comprises holding means (60) of the closure device (3) in the manifold (2) .

5. heat exchanger (1) according to any one of the preceding claims, characterized in that the mechanical connection between the manifold (2) and the closure device (3) is elastic.

6. Heat exchanger (1) according to any one of the preceding claims, characterized in that the closure device (3) comprises elastic holding means (20) able to maintain in the closed position the at least one flap (10). ) when the flow of gas to be cooled is less than one certain threshold.

7. Heat exchanger (1) according to the preceding claim, characterized in that the closure device (3) comprises prestressing means (50) of the elastic holding means (20).

8. heat exchanger (1) according to the preceding claim, characterized in that the elastic holding means (20) comprise a torsion spring (25) comprising two branches (22, 23) and a winding (21), the angular difference (A2) between the legs (22,23) of the spring (25) being reduced by a prestressing angle (A3) with respect to its rest position.

9. heat exchanger (1) according to the preceding claim, characterized in that the stiffness of the spring (25) torsion is between 0.025 N.mm/° and 0.2 N.mm/°, preferably between 0, 5 N.mm/° and 0.1 N.mm/°, and in that the prestressing angle (A3) is between 3 ° and 15 °, preferably between 5 ° and 1 °.

10. heat exchanger (1) according to any one of the preceding claims, characterized in that the closure device (3) is configured to close a predefined number of mouths (6) between 50% and 90%, preferably between 50% and 60% of the total number of mouths (6) of ducts (5) opening into the manifold (2).