EP1658419A1

EP1658419A1 - Device for thermal regulation of exhaust gas

Info

Publication number: EP1658419A1
Application number: EP04786013A
Authority: EP
Inventors: Silvia Guillen; Jose-Luis Lazaro; Carlos Da Silva; Bertrand Gessier
Original assignee: Valeo Thermique Moteur SA
Current assignee: Valeo Systemes Thermiques SAS
Priority date: 2003-08-29
Filing date: 2004-07-30
Publication date: 2006-05-24
Also published as: FR2859239B1; FR2859239A1; WO2005024193A1

Abstract

The invention relates to a device for the thermal regulation of exhaust gas. The inventive regulation device consists of: a heat exchanger (5) comprising an inlet (4) and an outlet (18) for the gases travelling along an exhaust line; a bypass (2) through which the gases can pass; and distribution means (26) which are used to transmit the gases through the bypass (2), through the heat exchanger (5) or through both of said elements in a shared manner. The device further comprises a casing (3, 19, 24) which is used to house at least the distribution means (26) and the bypass (2), the inlet (4) and/or the outlet (18) of the heat exchanger being disposed on the surface of said casing. The invention can be used for the thermal regulation of motor vehicle exhaust gases.

Description

DEVICE FOR THERMAL REGULATION OF EXHAUST GASES

The invention relates to devices for thermal regulation of gases flowing along an exhaust line at the outlet of thermal engines of motor vehicles.

Environmental standards impose a significant reduction in the emission levels of internal combustion engines of motor vehicles.

To reduce the formation of nitrogen oxides, devices are known for thermal regulation of the exhaust gases which exit a heat engine and go to a catalyst element of the type known under the designation "DENOX" and capable of reducing the nitrogen oxide content. These devices include a heat exchanger with an external bypass that allows the gases to reach the right temperature in the catalyst. The gases pass either through the exchanger to be cooled there, or in the bypass not to be cooled.

The main drawback of an external bypass is its size.

The subject of the invention is a device for thermal regulation of exhaust gases from a vehicle engine which overcomes this drawback thanks to the presence of an internal bypass heat exchanger.

This object is achieved, in accordance with the invention, by the fact that the device for thermal regulation of gases flowing along an exhaust line of a heat engine comprises:

- a heat exchanger having an inlet and an outlet for gases; - a bypass capable of being crossed by said gases;

- distribution means for transmitting the gases, either via the bypass or via the heat exchanger, or shared between these two directions, said device comprising a housing accommodating at least said distribution means and said bypass, the inlet and / or outlet of said heat exchanger being located on the surface of said housing.

Thus for the exhaust gases, the catalysis element can be used in a wide range of temperatures, or whatever the temperature of the exhaust gases, which makes it possible to operate the engine in lean mixture more often, or even whenever desirable to reduce fuel consumption.

Preferably, the heat exchanger and the bypass have at least one communication orifice allowing the introduction of the exhaust gases into said heat exchanger from said bypass.

In a preferred embodiment of the invention, the bypass is produced in the form of a central bypass tube coupled by a first end to the inlet of the control device to be supplied by the exhaust gases of the heat engine , a transfer tube surrounding the central bypass tube over at least part of its length for transferring the exhaust gases circulating in the vicinity of a second end of the central tube in the heat exchanger disposed around the transfer tube.

Thanks to these characteristics, the heat exchanger makes it possible to cool the exhaust gases which pass through it, effectively, without lowering the temperature of the exhaust gases circulating inside the branch which is too much. separated from the cooling circuit of the exchanger. It should also be noted that such a device can, according to the invention, be applied to the thermal regulation of any type of gas, in particular exhaust gas recirculated at the intake of the engine.

The bypass means are then coupled between the second end of the central bypass tube and an exhaust gas outlet orifice of the regulating device for transmitting the gases leaving the second end of the central bypass tube, either directly to the exhaust gas outlet of the control device when the bypass means are in an open position, either indirectly to the exhaust gas outlet of the control device via the heat exchanger connected to the transfer tube, when the bypass means are in a closed position, or shared between these two directions when the bypass means are in an intermediate position between the open position and the closed position.

According to another important characteristic of the invention, the central bypass tube is crossed in the vicinity of its second end by openings which bring the interior of the central bypass tube into communication with the transfer tube.

This arrangement prevents gases from entering the heat exchanger when the bypass means (generally a valve) are in a fully open position. To do this, the openings of the central tube are located very close to the second end of the central tube, which allows the pressure of the exhaust gases to drop before and after passing through the distribution means (generally a valve body). , and to make negligible gas leaks to the heat exchanger.

According to yet another characteristic of the invention, the heat exchanger comprises a bundle formed of a multiplicity of parallel tubes arranged all around the transfer tube and assembled with the transfer tube, between a first and a second manifold with which they communicate, the assembly formed by the transfer tube, the ^' bundle of tubes and the boxes manifolds being traversed by the exhaust gases passing through the openings of the central bypass tube located near its second end, while the bundle of tubes is cooled by a coolant circulating in the space left free between the tubes of the bundle .

When the valve is completely closed, the exhaust gases pass through the openings at the second end of the central bypass tube and circulate between the walls of the central bypass tube and the transfer tube towards the first manifold of the heat exchanger where they penetrate to distribute through tubes of the tube bundle. During their passage through the tubes of the bundle, the exhaust gases are cooled by the coolant which bathes the bundle of tubes before being directed towards the outlet of the regulating device.

According to another characteristic of the invention, the first manifold consists of an annular flange on which a cylindrical wall depends, while the first manifold is closed by a cover into which open the ends of the bundle tubes and a first end of the transfer tube.

Advantageously, the second manifold is projecting around a first end of a sleeve in which the second end of the central bypass tube is engaged and comprises a bottom delimited by a cylindrical wall of the sleeve in which the second end is engaged. of the central tube, and a second cylindrical wall surrounding the cylindrical wall of the sleeve, while the second manifold is closed by a cover in 1 PΓΓU I rf ^p hnnπ p.nt the ends of the bundle tubes. The bottom of the second manifold box advantageously has an annular opening centered on the longitudinal axis of the central bypass tube which places the interior of the second manifold in communication with a trunk-shaped exhaust gas outlet box. cone, connected by its largest base to the second manifold, the smallest base having an outlet orifice through which escape the exhaust gases leaving the regulating device.

In a preferred embodiment, the distribution means comprise a valve body comprising an inlet orifice coupled to the sleeve and an outlet orifice, opposite the inlet orifice, opening into the gas outlet box. exhaust.

The distribution means advantageously comprise a valve coupled between the heat exchanger and the bypass to transmit the exhaust gases, either directly from the inlet to the outlet when the valve is in the open position, or indirectly to the outlet by 1 'Intermediate heat exchanger when the valve is in the closed position, or shared between these two directions when the valve is in an intermediate position between the open position and the closed position.

In the invention, the heat exchanger is advantageously cooled by a mixture of water and glycol.

It is also advantageous for the cross-sections of the exhaust gas flows in the central tube and in the circuit formed by the transfer tube and the heat exchanger to be approximately constant.

In another embodiment of the invention, the bypass is produced in the form of a straight tube extending between an inlet and an outlet of the regulation, while the gas circulation circuit in the heat exchanger has a U-shape and communicates with the bypass tube, respectively with an upstream intersection on the inlet side and a downstream intersection on the outlet side, the bypass means being coupled between the bypass tube and the heat exchange box.

In this second embodiment of the invention, the bypass means advantageously comprise a butterfly type valve housed in the bypass tube between the upstream intersection and the downstream intersection.

In a third embodiment, the bypass is made in the form of a straight tube extending between an inlet and an outlet of the device, while the heat exchanger is made in the form of plates or tubes parallel to the longitudinal direction of the tube forming the bypass and communicating with the tube forming the bypass respectively with an upstream intersection on the inlet side and a downstream intersection on the outlet side, the distribution means being coupled between the bypass tube and 1 ' heat exchanger .

In a fourth and fifth embodiment the heat exchanger, the bypass and the distribution means are enclosed in the same housing. The heat exchanger is formed by two half-bundles of parallel plates or tubes composed of two parallel blocks in the form of rectangular parallelipipeds arranged on either side of the same branch conduit extending between an inlet and a out of the housing.

The valve is pivotally mounted in the bypass duct.

The blocks are kept separate inside the box between two parallel plates respectively forming the bottom and the cover of the box, while the bypass duct is delimited by the space between the two plates and by the side faces facing each other. opposite the two blocks. In the fourth embodiment, each half-beam consists of plates traversed by a coolant, separated from each other by spaces or interstices which communicate directly with the bypass duct.

In the fifth embodiment, each half-beam consists of tubes parallel to the longitudinal axis of the conduit which communicate by their respective ends with the bypass conduit via an inlet manifold and a outlet manifold fitted on the external faces of the housing around the ends of the bypass duct.

All of the configurations described above make it possible to obtain integration in a reduced space of the control device, which facilitates the rise in temperature of the DENOX catalysis element which can very quickly reach its operating point around 250 ° C. necessary for obtain an effective reduction of the nitrogen oxide content when the valve in the conduit or the bypass tube is in the open position.

Of course, other embodiments are possible, from the moment the device comprises an internal bypass associated with a heat exchanger, the internal bypass and the heat exchanger being mounted between the inlet and the outlet of the device. .

In another aspect, the invention relates to an installation for circulating exhaust gases for a heat engine, this installation comprising a device. thermal regulation of exhaust gases as defined above.

The regulating device is advantageously interposed between a three-way catalyst and a catalysis element, in particular of the "Denox" type. Other characteristics and advantages of the invention will become apparent on reading the description which follows with reference to the appended figures. In these figures:

FIG. 1 is a schematic sectional view of an exemplary embodiment of a device for thermal regulation of exhaust gases according to the invention;

FIG. 2 is an external front view of the thermal regulation device of FIG. 1;

- Figure 3 is a diagram of an installation comprising a regulating device according to the invention interposed between a three-way catalyst and a catalysis element; Figure 4 is a sectional view of a thermal control device according to a second embodiment of one invention, interposed between a three-way catalyst and a catalyst element;

- Figures 5 and 6 are a sectional view and a perspective view of a thermal regulation device according to a third embodiment of the invention comprising a heat exchanger formed by a bundle of parallel plates;

- Figures 7 and 8 are sectional views of a thermal regulation device according to a fourth and a fifth embodiment of the invention respectively comprising a heat exchanger formed by a bundle of parallel plates and a bundle of parallel tubes ;

- Figure 9 an exploded view of a thermal regulation device according to the fourth embodiment of

The invention; - Figures 10 and 11 are two perspective views of the thermal regulation device of Figure 9, in the assembled state, revealing the path of gas flow in the device when the valve of the distribution circuit is respectively in the open position and in the closed position;

- Figure 12 is a perspective view of a thermal regulation device according to the fifth embodiment ^• showing the path of gas flow in the device when the distribution valve is in the open position;

- Figure 13 a perspective view of a thermal control device according to the fifth embodiment showing the path of gas flow in the device when the valve is in the closed position; and

- Figure 14 a perspective view of a thermal regulation device according to the fifth embodiment showing the cooling circuit of the device.

The thermal control device of the exhaust gas, which is designated by ^'reference numeral 1 in Figure 1 is more particularly intended to operate in conjunction with a thermal engine of a motor vehicle.

The regulating device 1 comprises a central bypass tube 2 with a longitudinal axis XX ′, a first end of which is engaged in a gas inlet collar 3. The wall of the central bypass tube 2 is crossed in the vicinity of the second end of the tube by openings 4 which put

'in communication inside the central bypass tube 2 with a heat exchanger 5 via a transfer tube 6 surrounding the central bypass tube 2 over part of its length. The openings 4 thus constitute the inlet of the heat exchanger 5.

The heat exchanger 5 is formed in a known manner by a bundle formed by a multiplicity of parallel tubes 7 arranged all around the transfer tube 6 in a direction parallel to the axis XX 'and assembled with the transfer tube 6, between a first manifold 8 and a second manifold 9 with which they communicate so that the assembly formed by the transfer tube 6, the bundle of tubes 7 and the manifolds 8 and 9 can be traversed by the exhaust gases.

The first manifold 8 consists of an annular flange 10 on which a cylindrical wall 11 depends. The first manifold 8 is closed by a cover 12, forming a manifold, into which the ends of the tubes 7 of the bundle open and a first end of the transfer tube 6. The first manifold 8 is fixed by screws 13 against the gas inlet collar 3.

The second manifold 9 is formed projecting around a first end of a sleeve 14 in which is engaged the second end of the central bypass tube 2. It consists of a bottom 15 delimited by a cylindrical wall 16 of the sleeve 14 in which is engaged the end of the central bypass tube 2, and a second cylindrical wall 17 surrounding the cylindrical wall 16 of the sleeve. The second manifold 9 is closed by a cover 18, forming a collector, into which the ends of the tubes 7 of the bundle open. The cover 18 thus forms the outlet of the heat exchanger.

The bundle of parallel tubes 7 is disposed inside a cylindrical wall 19 concentric with the central bypass tube 2, closed at its ends by the covers 12 and 18 of the manifolds 8 and 9 and is cooled by a coolant such as as for example, a mixture of water and glycol, coming from the engine cooling circuit, not shown. The coolant enters the space left free between the tubes 7 of the bundle and the space delimited by the cylindrical wall 19 and the covers 12 and 18 of the manifolds 8 and 9, by an intake manifold 20 and an exhaust pipe 21 (FIG. 2) connected to the engine cooling circuit. The cover 18 thus constitutes the outlet of the heat exchanger 5.

The bottom 15 of the second manifold 9 has an annular opening 22 delimited by two circular edges centered on the longitudinal axis XX 'of the central bypass tube 2. The annular opening 22 connects the interior of the second manifold 9 with an exhaust gas outlet box 24, which has a flange 23 for fixing it to the manifold 9. The outlet box 24 has the shape of a truncated cone and is connected by its largest base to the manifold 9, the smallest base comprising an outlet orifice 25 through which escape the exhaust gases leaving the regulating device 1.

The sleeve 14 also puts the central bypass tube 2 into communication with the outlet box 24 for the exhaust gases by means of a valve 26 provided with a valve 27 and the body of which comprises an inlet port 28 coupled to the sleeve 14 and an outlet orifice 29, opposite the inlet orifice 28, opening opposite the outlet orifice 25. The valve body has the shape of a cylinder centered on the axis XX 'and it is connected to the outlet box 24 by a diametrical spacer 30.

The valve 27 is controlled in rotation by an actuator 31, for example a pneumatic valve, shown in FIG. 2, and makes it possible to control the temperature of the exhaust gases exiting through the orifice 25 of the outlet box 24.

The regulating device comprises a box, formed here by the gas inlet collar 3, the cylindrical wall 19 and the outlet box 24. This box accommodates at least the distribution means, that is to say here the valve 26 , and the branch 2. The inlet 4 and / or the outlet 18 de.1 'heat exchanger are located on the surface of said housing. Optimal operation of the device which has just been described can be obtained by taking particular care that the cross-sections of the exhaust gas flows in the central tube 2 and in the circuit formed by the transfer tube 6 and the heat exchanger. heat 5 are more or less constant, this in order to minimize the pressure drops in the circuits and the thermal losses in the central tube 2.

In order to prevent the gases from entering the heat exchanger when the valve 26 is fully open, the openings 4 of the central tube 2 are placed very close to the second end of the central tube, which allows the pressure of the gases exhaust fall before and after crossing the valve body, and greatly limit gas leakage to the heat exchanger 5. In this way, when the valve 27 is fully open, the exhaust gas arriving by the inlet flange 3 are directed through the central bypass duct 2 and the valve body 26 directly to the outlet manifold 24.

When the valve 27 is completely closed, the exhaust gases pass through the openings 4 located at the second end of the central bypass tube 2 and circulate between the wall of the central bypass tube 2 and that of the transfer tube 6 towards the first manifold 8 of the heat exchanger 5 where they penetrate to be distributed through the tubes 7 of the tube bundle. During their journey through the tubes 7 of the bundle, the exhaust gases are cooled by the coolant which bathes the bundle of tubes 7, then they are directed towards the outlet box 2.

When the valve 27 is in an intermediate open position, it can be controlled so as to control the flow of exhaust gases leaving the valve body 26 and the flow of gas flowing in the heat exchanger 5 to obtain a precise temperature value determined at the outlet in the outlet orifice 25 of the outlet box 24. Reference is now made to FIG. 3 which schematically illustrates the integration of a regulation device 1 according to the invention between a catalyst 32 of the three-way type and a catalyst element 33 of the "Denox" type. The catalyst 32 is connected to the manifold 34 of a heat engine 35 and is thus supplied by the latter's exhaust gases. At the outlet of the catalyst 32, the exhaust gases are cooled to the right temperature thanks to the regulating device of the invention, then being sent to the catalysis element 33 which decreases the content of nitrogen oxides in the gases d 'exhaust. These are then evacuated to the outside via a conduit 36.

In the diagram of FIG. 3, the regulating device 1 can be constituted by a regulating device as shown in FIGS. 1 and 2, or also by another regulating device with internal bypass meeting the characteristics of the invention.

FIG. 4 schematically illustrates another thermal regulation device 1 according to the invention. This device 1 comprises an inlet 37 and an inlet 38 connected respectively to the outlet of a catalyst 32 similar to that of FIG. 3, and to the inlet of a catalyst element 33 similar to that of FIG. 3. also shown in Figure 4 the manifold 34 of the exhaust gas and the pipe 36 which discharges the exhaust gas to the outside.

In the embodiment of FIG. 4, the bypass is produced here in the form of a straight tube 39 extending between the inlet 37 and the outlet 38 of the thermal regulation device.

The device further comprises a heat exchanger 40 provided with a TJ-shaped gas circulation circuit communicating with the bypass tube 39, respectively with an upstream intersection 41 on the side of the inlet 37 and with a downstream intersection 42 on the side of the outlet 38. The heat exchanger 40 defines two circulation branches 43 and 44 connected by a U-shaped bend 45. An intermediate partition 46 defines the inlet and the outlet of the branches 43 and 44.

The device 1 of FIG. 4 further comprises a butterfly type valve 47 housed in the bypass tube 39 between the upstream intersection and the downstream intersection so as to be coupled between the bypass tube and the heat exchange tube. heat. This bypass valve is pivotally mounted about an axis 48.

When the valve is in the open position, the exhaust gases are transmitted directly from the inlet 37 to the outlet 38. When the valve is in the closed position, the exhaust gases are transmitted by the heat exchanger 40. Finally , when the valve is in an intermediate position •, the exhaust gases are shared between the tube 39 and the heat exchanger 40. ^(~

The regulating device comprises a housing 39 'which, as in the previous embodiment, receives at. minus the distribution means, ie the valve 47 and the bypass 39. The inlet (upstream intersection 41) and / or the outlet (downstream intersection 42) of the heat exchanger are located on the surface of said housing . The coolant circulates in a space 45 'left free between the gas circulation branches 43, 44 and the internal wall of the tube 40.

FIGS. 5 and 6 illustrate an alternative embodiment of the thermal regulation device of FIG. 4. This device comprises, like the device of FIG. 4 where the homologous elements bear the same references, a bypass conduit in the form of a tube 39 accommodating distribution means in the form of a valve valve 47 of the butterfly type controlled similarly to the valve 27 of FIG. 1 by an actuator 31. The bypass tube 39 plays the role of the housing 39 ′ and extends between an inlet 37 and an outlet 38 connected respectively, as shown in FIG. 3, to the outlet of a catalyst 32 similar to that of FIG. 3, and to the inlet of a catalysis element 33 similar to that of FIG. 3.

The device further comprises a heat exchanger 40 communicating with the bypass tube 39 respectively with an upstream intersection branch 41 on the side of the inlet 37 and a downstream intersection branch 42 on the side of the outlet 38. To limit at the maximum the pressure drops between the inlet 37 and the outlet 38 of the exchanger, it is advantageous for the flow sections in the circuit formed by the bypass tube 39, the upstream and downstream intersection branches 41, 42 and the heat exchanger 40 are more or less constant.

The heat exchanger 40 is formed, as shown in FIG. 6, of a bundle of plates or tubes 49 parallel to the longitudinal direction of the tube 39 and traversed by a coolant circulating between an inlet orifice 51 and a outlet orifice 52. To increase the calorific power dissipated by the exchanger, all or part of the plates 49 can be formed in known manner by turbulence-generating plates.

The valve flap 47 is pivotally mounted in the bypass tube 39 between the upstream intersection branch 41 and the downstream intersection branch 42.

The gas enters the device through the inlet orifice 37 of the tube 39. The regulation of its temperature is controlled by the valve 47 of the valve. When the valve 47 is in the open position, the exhaust gases are transmitted directly from the inlet 37 to the outlet 38. When the valve 47 is in the closed position, the exhaust gases follow a "C" shaped circuit. . They are transmitted in the heat exchanger 40 by the branch of intersection 41 and exit from the heat exchanger 40 by the branch of intersection 42 in the direction of the outlet 38 for entering the catalysis element 38. Finally, when the valve is in an intermediate position, the exhaust gases are shared between the tube 39 and the heat exchanger 40.

Figures 7 to 13 illustrate two other embodiments of a regulation device according to the invention.

In these examples, where the elements homologous to those of FIGS. 5 and 6 bear the same references, the heat exchanger 40, the bypass duct 39 and the distribution means 47 are enclosed in the same housing 39 ′.

The heat exchanger is constituted by two half-bundles of parallel plates or tubes forming two parallel blocks 40a and 40b in the form of parallelipiped rectangles arranged on either side of the same branch conduit 39 extending partially between the inlet 37 and an outlet 38 of the bypass duct 39, the inlet 37 and the outlet 38 being respectively connected to the outlet of a catalyst 32 similar to that of FIG. 3, and to the inlet of an element of catalysis 33 similar to that of FIG. 3.

The blocks 40a, 40b are kept separate inside the housing 39 'between two parallel rectangular plates 53 and 54 respectively forming a bottom wall 53 and a closing wall 54 of the housing 39'. The bypass duct 39 is delimited by the space between the two plates 53 and 54 and by the lateral faces 55 and 56 of the two blocks 40a, 40b facing each other and it is extended outside this space by two portions of tubes 57, 58 allowing the connection of the bypass duct 39 between the outlet of the catalyst 32 and the inlet of the catalyst element 33.

The valve 47 of the valve is introduced into the bypass tube 39 through an orifice 47a passing through the closure plate 54 of the housing 39 'and is kept suspended in the bypass tube by a support plate 47b screwed onto the closure plate 54 . In FIGS. 7, 9, 10 and 11 the side walls 59 to 62 of the housing 39 'are produced by folding at right angles to two opposite ends of the plates 53 and 54 and by fitting the folded ends of each plate into the U formed by the folded parts of the other plate. The side walls 59, 60 of the housing 39 ', which are parallel to the bypass duct 39, respectively cover the faces of the blocks 40a, 40b, opposite the side faces 55, 56 of the two blocks 40a, 40b facing each other. The blocks 40a, 40b can thus be fixed to the housing 39 'on the walls of the corresponding dihedron formed by the bottom plate 53 and the side walls 59, 60 parallel to the bypass pipe 39.

Each half-beam is constituted by parallel plates 61 stacked above the bottom plate 53 and traversed by a cooling liquid circulating between an inlet pipe 63a and an outlet pipe 63b. The half-beams making up the blocks 40a and 40b are interconnected by a coolant circulation duct 64. The plates are separated from each other by spaces or interstices 65 which communicate directly with the bypass duct 39.

As shown in Figure 10, when the valve 47 of the valve is in the open position, the exhaust gases are transmitted directly from the inlet 37 to the outlet 38. When the valve 47 of the valve is in the closed position as the shows FIG. 11, the exhaust gases are transmitted in the heat exchanger 40 by the interstices 65 of the plates and travel in the exchanger 40 a circuit, as shown by the arrows, in the shape of "O". Finally, when the valve is in an intermediate position, the exhaust gases are shared between the tube 39 and the heat exchanger 40.

In FIGS. 8, 12 and 13, where the elements homologous to those in FIGS. 7, 9, 10, 11 bear the same references, the housing 39 ′ comprises a bottom plate 53, a plate of closure 54 and two side walls 59, 60 parallel to the longitudinal axis of the bypass duct 39. The side walls 59, 60 of the housing 39 ', parallel to the bypass duct 39 respectively cover the faces of the blocks 40a, 40b opposite the lateral faces 55, 56 facing the two blocks 40a, 40b.

Unlike the previous example, the lateral faces 55, 56 facing the blocks 40a, 40b no longer communicate with the bypass duct 39, but they are isolated from it either by a single plate respectively 66, 67 or by two plates separated by an air knife or by a thermally insulating material arranged in a spacer between the bottom wall 53 and the closure wall of the housing 54. The blocks 40a, 40b are fixed to the housing 39 'against the walls of the corresponding dihedron formed by the bottom plate 53 and the side walls 59, 60 parallel to the bypass pipe 39.

The ends of the housing 39 ′ which were covered in FIGS. 9, 10, 11 by the side plates 61, 62 perpendicular to the longitudinal axis of the bypass duct 39 are open and communicate respectively with the inlet and the outlet of the device at through a manifold respectively 68, 69.

The heat exchanger consists of two half-bundles of tubes 70 parallel to the longitudinal axis of the bypass duct 39. The two half-bundles communicate by the respective ends of their tubes 70 with the bypass duct 39 by the intermediate an inlet manifold 68 in the shape of a truncated pyramid at its top and an outlet manifold 69 also in the shape of a truncated pyramid at its top.

The two manifolds 68 and 69 have their large bases fitted onto the external faces of the housing 39 'around the ends of the bypass duct 39. They communicate respectively with the inlet 37 and the outlet 38 of the device regulating by conduits 57, 58 engaged in orifices made on the smallest bases of the manifolds 68 and 69.

When the valve 47 of the valve is in the open position, the exhaust gases are transmitted directly from the inlet 37 to the outlet 38 through the bypass duct 39. When the valve 47 of the valve is in the closed position as shown in FIG. 9, the exhaust gases are transmitted into the heat exchanger 40 by the inlet manifold 68 and exit through the outlet manifold 69 after having followed a path in the form of ^{, λ} 0 ". Finally when the valve 47 of the valve is in an intermediate position, the exhaust gases are shared between the duct 39 and the heat exchanger 40.

As indicated above, the thermal regulation device 1 according to the invention can be used in other applications.

Claims

claims

1. A device for thermal regulation of gas circulating along an exhaust line of a heat engine, comprising: - a heat exchanger (5; 40) having an inlet (4; 41) and an outlet (18; 42) for gases; - a bypass (2; 39) capable of being crossed by said gases;

- distribution means (26; 47) for transmitting the gases, either via the bypass (2; 39), or via the heat exchanger (5; 40), or in a shared manner between these two directions, characterized in that said device comprises a housing (3, 19, 24; 39 ') accommodating at least the said distribution means (26; 47) and said bypass (2; 39), the inputs (4 ; 41) and / or outlet (18; 42) of said heat exchanger being located on the surface of said housing.

2. Device according to claim 1, characterized in that the circulation of gases in the heat exchanger is carried out inside a cylinder (19) concentric with said bypass (2).

3 .. Device according to one of claims 1 and 2, characterized in that said heat exchanger (5; 40) and- said bypass (2; 39) have at least one communication orifice (4; 41) allowing the introduction of the exhaust gases into said heat exchanger from said bypass.

4. Device according to one of claims 1 and 3, characterized in that the bypass is produced in the form of a central bypass tube (2), coupled by a first end to the inlet of the device to be supplied by the exhaust gases from the heat engine, in that a transfer tube (6) surrounds the central bypass tube (2) over at least part of its length to transfer the exhaust gases circulating in the vicinity of a second end of the central tube in the heat exchanger (5) arranged around the transfer tube (6), and in that the distribution means (26) are coupled between the second end of the central bypass tube (2) and an orifice outlet (25) of the exhaust gases from the regulating device (1) to transmit the gases leaving the second end of the central bypass tube (2), either directly to the outlet port (25) of the exhaust of the regulating device when the distribution means (26) are in an open position, either indirectly towards the outlet orifice (25) of the exhaust gases of the regulating device (1) via the exchanger heat (5) connected to the transfer tube (6) when the distribution means (26) are in a closed position, or in a split manner between these two directions when the distribution means (26) are in an intermediate position between the open position and position closed.

5. Device according to claim 4, characterized in that the central bypass tube (2) is crossed in the vicinity of its second end by openings (4) which put in communication the interior of the central bypass tube (2) with the transfer tube (6).

6. Device according to one of claims 4 and 5, characterized in that the heat exchanger (5) comprises a bundle formed by a multiplicity of parallel tubes (7) arranged all around the transfer tube (6) and assembled with the transfer tube (6), between a first manifold box (8) and a second manifold box (9) with which they communicate, the assembly formed by the transfer tube (6), the tube bundle (7 ) and the manifolds 8, 9) being traversed by the exhaust gases passing through the openings (4) of the central bypass tube (2) located in the vicinity of its second end, and in that the bundle of tubes (7) is refrigerated by a coolant circulating in the space left free between the tubes (7) of the bundle.

7. Device according to claim 6, characterized in that the first manifold box (8) consists of an annular flange (10) on which a cylindrical wall (11) depends, and in that the first manifold box (8) is closed by a cover (12) into which open the ends of the tubes (7) of the bundle and a first end of the transfer tube (6).

8. Device according to one of claims 6 and 7, characterized in that the second manifold box (9) is projecting around a first end of a sleeve (14) in which is engaged the second end of the tube central bypass (2) and comprises a bottom (15) delimited by a cylindrical wall (16) of the sleeve (14) in which is engaged the second end of the central tube (2), and a second cylindrical wall (17) surrounding the cylindrical wall (16) of the sleeve (14), and in that the second manifold (9) is closed by a cover (18) into which the ends of the tubes (7) of the bundle open.

9. Device according to claim 8, characterized in that the bottom (15) of the second manifold (9) has an annular opening (22) centered on the longitudinal axis of the central bypass tube (2) which puts in communication the interior of the second manifold (9) with an exhaust gas outlet box (24) in the shape of a truncated cone, connected by its larger base to the second manifold (9), the smaller base comprising an outlet orifice (25) through which escape the exhaust gases leaving the regulating device (1).

10. Device according to one of claims 8 and 9, characterized in that the distribution means comprise a valve body (26) having an inlet port (28) coupled to the sleeve (16) and an outlet port ( 29), opposite the inlet, opening into the exhaust gas outlet box (24).

11. Device according to one of claims 1 to 10, characterized in that the distribution means comprise a valve (26; 47) coupled between the heat exchanger (5; 40) and the bypass (2; 39) for transmit the exhaust gases, either directly from the inlet to the outlet when the valve is in the open position, or indirectly to the outlet via the heat exchanger (5; 40) when the valve is in the position closed, or shared between these two directions when the valve (26; 47) is in an intermediate position between the open position and the closed position.

12. Device according to one of claims 1 to 11, characterized in that the heat exchanger (5) is cooled by a mixture of water and glycol.

13. Device according to one of claims 10 to 12, characterized in that the sections of the exhaust gas flows in the central tube (2) and in the circuit formed by the transfer tube (6) and the exchanger heat (5) are almost constant.

14. Device according to claim 1, characterized in that the bypass is produced in the form of a straight tube (39) extending between an inlet (37) and an outlet (38) of the device, in that the circuit gas circulation in the heat exchanger (40) has a "U" shape and communicates with the bypass tube (39), respectively with an upstream intersection (41) on the inlet side (37) and a downstream intersection (42) on the outlet side (38), and in that the distribution means (47) are coupled between the bypass tube and the heat exchange tube.

15. Device according to claim 14, characterized in that the distribution means comprise a valve (47) of the butterfly type housed in the bypass tube (39) between the upstream intersection (41) and the downstream intersection (42) .

16. Device according to claim 1, characterized in that the bypass is produced in the form of a straight tube (39) extending between an inlet (37) and an outlet (38) of the device, and in that the heat exchanger (40) has a gas circulation circuit in the form of ^{, λ} C "and is

- produced in the form of plates or tubes parallel to the longitudinal direction of the straight tube forming the bypass and communicate with the bypass tube (39), respectively with an upstream intersection (41) on the inlet side and with an intersection downstream (42) on the outlet side, and in that the distribution means (47) are arranged in the bypass tube (39) between the upstream intersection (41) and the downstream intersection (42).

17 Device according to claim 16 wherein the gas flow sections in the bypass tube, in the upstream intersection, in the downstream intersection and in the exchanger are substantially constant.

18. Device according to claim 1, characterized in that the bypass (39), the heat exchanger (40) and the distribution means (47) are enclosed in the same housing (39 ') and in that the heat exchanger (40) has a gas circulation circuit in the form of "0" and is formed by two half-bundles of plates (61) or parallel tubes (70) composed of two parallel blocks (40a, 40b) in form of parallelipiped rectangles arranged on either side of a conduit forming the bypass (39).

19. Device according to claim 18, characterized in that the blocks (40a, 40b) are kept separate inside the housing (39 ') between two parallel plates (53,54) respectively forming the bottom (53) and a closure plate (54) of the housing (39 ') and in that the bypass duct (39) is delimited by the space between the two plates (53,54) and by the lateral faces (55,56) in vis-à-vis the two blocks (40a, 40b).

20. Device according to one of claims 16 to 19, characterized in that the distribution means comprise one and only one valve (47) of valve pivotally mounted in the bypass duct (39).

21. Device according to one of claims 18 to 20, characterized in that each half-beam making up the blocks (40a, 40b) is constituted by parallel cooling plates (61) separated from each other by spaces or interstices (65) which communicate directly with the bypass duct (39).

22. Device according to one of claims 18 to 20, characterized in that the two half-beams are composed of tubes (70) parallel to the longitudinal axis of the conduit (39) which communicate by their respective ends with the conduit of bypass (39) via an inlet manifold box (68) and an outlet manifold box (69) fitted on the external faces (53,54,59,60) of the housing (39 ') around the ends of the bypass duct (39).

23. Device according to claim 1, characterized in that the gas circulation circuit in the heat exchanger is produced inside a concentric cylinder (19) at said branch (2).

24. Device according to claim 1, characterized in that the gas circulation circuit has the shape of a "U", the two ends of the "U" (41,42) being in communication with the ends of said branch ( 39).

25. Device according to claim 1, characterized in that the gas circulation circuit has the shape of a "C" (40), the two ends of the "C" (41,42) being in communication with the ends of said derivation (39).

26. Device according to claim 1, characterized in that the circulation circuit of the αaz has the form of an ⁿ O " crossed by said branch (39) with which it communicates.

27. Installation for circulating the exhaust gases for a heat engine, characterized in that it comprises a device for thermally regulating the exhaust gases according to one of claims 1 to 26.

28. Installation according to claim 27, characterized in that the regulation device (1) is interposed between a three-way catalyst (32) and a catalysis element (33).