WO2021155909A1

WO2021155909A1 - A waste heat recovery assembly for a vehicle

Info

Publication number: WO2021155909A1
Application number: PCT/EP2020/052716
Authority: WO
Inventors: Aime MARROCCO; Lionel Simon; Nicolas Espinosa; Thomas Reiche
Original assignee: Volvo Truck Corporation
Priority date: 2020-02-04
Filing date: 2020-02-04
Publication date: 2021-08-12

Abstract

The invention relates to a waste heat recovery assembly (20) for a vehicle. The waste heat recovery assembly (20) comprises: - a Rankine system (30) including a set of main components, namely a tank (32), a pump (36), a heat exchanger (33), an expander (34) and a condenser (35), connected by pipes for carrying a working fluid; - a supporting structure (40) which supports at least said main components of the Rankine system. The supporting structure (40) has an interface (45) for mounting the waste heat recovery assembly (20) on a chassis (3) of the vehicle, and comprises a bracket (40) to which are attached all main components (32-36).

Description

A waste heat recovery assembly for a vehicle

TECHNICAL FIELD

The invention relates to a waste heat recovery assembly for a vehicle, especially a heavy- duty vehicle, such as a truck, a bus or a working machine. The invention further relates to a vehicle comprising such a waste heat recovery assembly.

BACKGROUND

It has long been proposed to provide vehicles with an engine arrangement equipped with a waste heat recovery assembly, i.e. a system assembly use of the thermal energy which is contained in hot exhaust gases emitted by the internal combustion engine, or in other engine fluids, and which would otherwise be lost.

Such a waste heat recovery assembly allows lowering fuel consumption and reducing C02 emissions.

One example of a waste heat recovery assembly comprises a Rankine system, which comprises a circuit in which a working fluid flows in a closed loop and undergoes successive processes according to the Rankine thermodynamic cycle: - the working fluid, which is a liquid at this stage, is pumped, i.e. compressed, from low to high pressure;

- the high pressure working liquid is evaporated into a working gas by the heat source, for example by the exhaust gases;

- the working fluid, which is a gas at this stage, is expanded in an expander; - finally, the working fluid is condensed in a condenser.

As a result, at least part of the thermal energy of the heat source used to evaporate the working fluid is recovered in the expander under the form of mechanical energy. It is conventional to transform that mechanical energy into electricity thanks to a generator driven by the expander, but it is also known to mechanically connect an output shaft of the expander to the driveline of the vehicle so that the energy recovered in the expander is re used directly in mechanical form to assist in propelling the vehicle.

A vehicle equipped with a waste heat recovery assembly is disclosed in WO 2014/064484 A1. In this publication, the main components of the Rankine system are fixed to a frame 32 which comprises a structure of beams 33 forming a kind of housing and supporting various components of the Rankine system 13, as well as walls 34 closing some of the housing faces. The problem of such frame enclosing the components of the Rankine cycle is that it is quite bulky. In addition, the frame makes it difficult to access the components of the Rankine cycle, so that it seems complicated to change only one of the components of the Rankine cycle: In practice, this problem of access makes it necessary to change the entire system.

SUMMARY

An object of the invention is to provide an improved waste heat recovery assembly which can overcome some drawbacks of the prior art, especially from a packaging perspective.

The invention concerns a waste heat recovery assembly for a vehicle, comprising:

- a Rankine system including a set of main components, namely a tank, a pump, a heat exchanger, an expander and a condenser, connected by pipes for carrying a working fluid;

- a supporting structure which supports at least said main components of the Rankine system, the supporting structure having an interface for mounting the waste heat recovery assembly on a chassis of the vehicle;

According to the invention, the supporting structure is a bracket to which are attached all main components.

Basically, the main components are attached to the bracket using fasteners such as bolts and mounting members. In a variant not shown, any other fastening means (rivet, screws and the like) could be used to attach the main components of the Rankine system to the bracket.

Owing to the invention, all main components of the Rankine system are secured to the bracket, on various respective areas on the bracket. These main components can be located on one single side of the bracket. Alternatively, the main components can be located on several sides of the bracket: the bracket is then arranged between the main components; in other words the main components are located around the bracket.

In fact, this bracket acts as a tree to support the different components: It is central and enables an easy access to the different components for maintenance. Also, this bracket can integrate optionally working fluid passage(s) to distribute the fluid, minimizing the connections and the risk of high inflammable gas to be released in the Environment.

In another embodiment, the pump and the expander are aligned along the same axis.

In another embodiment, the pump, the expander and the E-motor are aligned along the same axis.

By the term “bracket”, it is meant a “non-closed” structure, versus a box-like structure (such as the one of WO 2014/064484 A1). Such an “open” arrangement, as compared to conventional solutions in which the Rankine system is located inside a casing comprising multiple supporting walls or beams, has many advantages, among which:

- the overall space occupied is reduced, which is of significant importance as available space is generally scarce on a vehicle;

- the weight is also reduced;

- accessibility, manufacturing and maintenance of the Rankin system components (i.e. the main components but also pipes and possible other components) are greatly facilitated;

- air flow, especially for cooling, is improved.

The invention therefore allows a fairly easy implementation of the waste heat recovery assembly on a vehicle, in a limited space. It further allows reducing the production cost.

In an embodiment, the bracket has opposite first and second sides. It supports some of the main components of the Rankine system on the first side, and some others of the main components on the second side. These main components which are located on opposite sides of the bracket are therefore easily accessible. One or several of the main components, such as typically the heat exchanger, can be secured to the bracket at a different area.

The bracket may extend substantially transversally in the mounted position.

In an embodiment, the supporting structure consists of said bracket as a single supporting member. In other words, the supporting structure has no other bracket forming a supporting member, nor any other supporting member. However, the supporting structure may include elements having other functions, such as fasteners, reinforcing members, etc. The waste heat recovery assembly may define a virtual envelope having a parallelepiped shape having faces which, in the mounted position, comprise (the directions being defined with respect to the vehicle):

- an upper face and a lower face which are substantially horizontal;

- a front face and a rear face which are substantially orthogonal to the longitudinal direction;

- an internal side face and an external side face which are substantially orthogonal to the transverse direction; the virtual envelope enclosing the whole waste heat recovery assembly and its faces being tangent to the waste heat recovery assembly.

In a variant not shown, at least one or more protection shield(s) or a grill can be used to drive properly (i.e. optimize) the airflow towards the condenser.

In other words, the virtual envelope is the virtual box enclosing the waste heat recovery assembly as close as possible.

In an embodiment, the bracket is located within the virtual envelope defined by the waste heat recovery assembly, the bracket not being coincident with any face of the virtual envelope. Thus, the bracket is centrally located in the virtual envelope. The term “centrally” dos not mean that the bracket is arranged in the middle of the virtual envelope, i.e. halfway between opposite faces thereof. It rather means that the bracket does not form any face of the virtual envelope, that the bracket is not located parallel and in close proximity to any face of the virtual envelope. However, the fact that the bracket is not coincident with any face of the virtual envelope does not exclude that one face of the virtual envelope includes a portion of the bracket, such as an edge.

At least one face of the virtual envelope may be fully open, which means that said face has no wall, no peripheral edge, no inner beam joining edges of said face. Such a “fully open face” may however include a portion of the bracket, such as an edge. Preferably, at least two faces, more preferably at least three faces, or even all faces of the virtual envelope, are fully open.

In an embodiment, at least the front face and rear face of the virtual envelope are fully open. The bracket may comprise a main wall which is substantially vertical and transversal when the waste heat recovery assembly is mounted on a vehicle chassis. The main wall may have a lower portion, which preferably supports the condenser, and an upper portion which preferably supports the pump, the tank and the expander.

The heat exchanger may be arranged substantially vertically and longitudinally, i.e. orthogonal to the bracket main wall.

The bracket can further include bearing structures for the Rankine system components (which include the main components and possible other components), holes for receiving fasteners, and openings for receiving connecting elements between the Rankine system components. Such connecting elements may provide a mechanical connection (such as belts) or a fluid connection (such as pipes).

The Rankine system may further comprise at least one component among a fan, an electric motor, a filter for the working fluid, a recuperator (i.e. an internal heat exchanger for increasing system efficiency).

Advantageously, at least one additional component is attached to the bracket, said additional component being chosen among: a fan; an electric motor; a filter for the working fluid; and a recuperator.

Typically, the fan faces the condenser and is secured to the bracket on the side opposite the condenser, an opening being provided in the bracket for allowing air to flow from the fan to the condenser, a shroud being preferably provided between a fan outer ring and the bracket.

Advantageously, the electric motor is drivingly connected to the expander, the electric motor being for example secured to the bracket on the side opposite the expander and connected to the expander by means of a belt received in an opening of the bracket. As previously explained, the invention allows reducing the waste heat recovery assembly dimensions. For example, the overall dimensions of the waste heat recovery assembly are:

- height: less than 710 mm;

- width: less than 760 mm;

- length: less than 400 mm; with reference to the mounted position of the waste heat recovery assembly on a vehicle chassis.

By comparison, the overall dimensions of a conventional waste heat recovery box is:

- height: 1800 mm;

- width: 800 mm;

- length: 1200 mm;

Preferably, the bracket delimits at least one channel for the passage of fluid or electric cable(s).

Preferably, the bracket delimits at least one recess for receiving a seal ring, said recess being formed around one end of a fluid channel.

Advantageously, the bracket includes at least one boss to which is attached a sensor, for example a pressure or a temperature sensor.

The invention also relates to a vehicle comprising a chassis, an internal combustion engine installed on the chassis and an exhaust line capable of collecting exhaust gases from said engine, wherein the vehicle further comprises a waste heat recovery assembly as previously described, the waste heat recovery assembly being mounted on the vehicle chassis, wherein the working fluid of the Rankine system can be successively evaporated in the heat exchanger by heat exchange with the exhaust gases, expanded in the expander, condensed in the condenser and compressed in the pump.

Preferably, the waste heat recovery assembly is arranged between the two longitudinal beams of the chassis. Preferably, the bracket of the waste heat recovery assembly is hooked on a flange, which is bolted on one side of a longitudinal beam of the chassis, typically on the lateral side. The waste heat recovery assembly is therefore hung on this flange.

A mechanism is advantageously provided to prevent the waste heat recovery assembly from unhooking from the flange during normal use of the vehicle.

Further advantages and advantageous features of the invention are disclosed in the following description and in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the appended drawings, below follows a more detailed description of embodiments of the invention cited as examples.

In the drawings:

Fig. 1 is a perspective view of a vehicle comprising a waste heat recovery assembly according to an embodiment the invention;

Fig. 2 is a schematic and partial representation of the vehicle of Figure 1;

Fig. 3, 4 and 5 are perspective views of a waste heat recovery assembly, viewed from different orientations;

Fig. 6 and 7 are perspective views of a supporting structure of a waste heat recovery assembly, viewed from different orientations;

Fig. 8 is a schematic and partial representation of a vehicle comprising a waste heat recovery assembly according to another embodiment the invention;

Fig. 9 is a schematic and partial view of Figure 8 according to a transverse cross-section; Fig. 10 schematically shows an internal arrangement of the waste heat recovery assembly of Figure 8;

Fig. 11 is a schematic and partial representation of a vehicle comprising a waste heat recovery assembly according to still another embodiment the invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

Figure 1 shows a vehicle 1 , such as a truck, which comprises a cab 2 mounted on a chassis 3 supported by front wheels 4 and rear wheels 5. Z is defined as the vertical direction, X is defined as the longitudinal direction of the vehicle 1 , and Y is defined as the transverse direction of the vehicle 1. The chassis 3 can typically comprise at least one longitudinal beam 6, and for example two lateral beams 6 extending longitudinally and connected by transverse bars (not shown).

As schematically and partially illustrated in figure 2, the vehicle 1 further comprises an internal combustion engine 7 installed on the chassis 3. The engine 7 is able to drive the drive wheels 4 of the vehicle 1, through a driveline 8. The driveline 8 can include mainly a clutch 9, a gearbox 10, a propulsion shaft 11 , and at least one drive axle comprising for example a differential 12 and a drive shaft 13 for each of a left and of a right drive wheel 4.

An exhaust line 15 is provided for collecting the exhaust gases from the engine 7, i.e. the gases which result from the combustion in the engine 7.

The vehicle 1 is also equipped with a waste heat recovery assembly 20 which is mounted on the chassis 3. The waste heat recovery assembly 20 basically comprises a Rankine system 30 and a supporting structure 40 for mounting on the vehicle chassis 3.

The Rankine system 30 comprises a circuit 31 forming a loop, and includes a tank 32 for a working fluid. In said circuit 31, the working fluid is successively evaporated in a heat exchanger 33 - or boiler - by heat exchange with the exhaust gases flowing in the exhaust line 15, expanded in an expander 34, condensed in a condenser 35, and compressed in a pump 36.

The tank 32, pump 36, heat exchanger 33, expander 34 and condenser 35 form the main components of the Rankine system 30. The pump 36, heat exchanger 33, expander 34 and condenser 35 are arranged in this order in the loop 31 and connected by pipes carrying the working fluid.

The engine exhaust gases could be exhaust gases circulating in a recirculation circuit for being fed to the engine intake. Other heated engine fluids could also be used as heat source for the Rankine system. The Rankine system could have several heat exchangers where the working fluid would be heated successively by several different engine heated fluids. The vehicle 1 can comprise an exhaust directional valve 21 located in the exhaust line 15 and capable of directing part of the exhaust gases towards the heat exchanger 33. The rest of the exhaust gases continue in the exhaust line 15 without flowing through the heat exchanger 33. The exhaust directional valve 21 makes it possible to control the amount of gases directed to the heat exchanger 33 and to by-pass partly or totally the heat exchanger 33 for limiting the amount of heat that is provided to the Rankine system 30, for example depending on the vehicle cooling capacity.

The gases resulting from the evaporation of the working fluid in the heat exchanger 33 are carried to the expander 34 by a pipe 22. The expander 34 may be a Pelton turbine, a centrifugal turbine, a screw expander, a piston expander, etc.

Downstream from the expander 34, a pipe 23 carries the gas towards the condenser 35. Condensation of the gas in the condenser 35 may result from heat exchange with ambient air moving through the condenser 35. Alternatively, or in addition, condensation may result from heat exchange with a cooling fluid, such as the engine cooling fluid flowing in an engine cooling circuit 24.

The condensed working fluid then flows to the pump 36, through a pipe 25. Finally, the pump 36, which may be driven by an electric motor 37, pumps the working fluid, which is a liquid at this stage, from low to high pressure before it enters the heat exchanger 33. The fluid is carried in a pipe 27 from the pump 36 to the heat exchanger 33.

The tank 32 may be located outside the loop 31 , but connected to said loop 31 by a pipe 26 which may open in pipe 25, between the condenser 35 and the pump 36.

In addition to the above described main components (tank 32, pump 36, heat exchanger 33, expander 34 and condenser 35), the Rankine system 30 may further comprises at least one component among:

- an electric motor 39 which is drivingly connected to the expander 34;

- a fan 44 for promoting air flow through the condenser 35 and thus improving cooling and condensation of the working fluid;

- a filter 28 for the working fluid; the filter 28 may be arranged on pipe 25, upstream from the pump 36 and preferably downstream from the tank 32; - a recuperator 43, which is an additional heat exchanger between the working fluid - which leaves the pump 36 to the heat exchanger 33 - and a hot fluid, such as the fluid exiting the expander 34 before it enters the condenser 35 (this not being illustrated In figure 2 for the sake of simplification); the recuperator 43 is therefore arranged on pipe 27, and allows -heating the working fluid before it enters the heat exchanger 33.

Possible additional components, not shown, of the Rankine system 30 include:

- a sub-cooler, arranged for example between the tank 32 and the pump 36;

- a lubricating circuit.

The thermal energy of the exhaust gases is recovered in the expander 34, namely by the rotation of an output shaft 38 of the expander 34.

The output shaft 38 can be mechanically connected to the engine crankshaft or to the driveline - in particular to the drive wheels differential 12, as schematically represented in figure 2 - in order to transfer torque from the expander 34 to the driveline 8. Then, energy from the expander 34 is recovered in mechanical form.

Alternatively, energy from the expander 34 can be recovered in electrical form. For that purpose, the electric motor 39 may be driven by the expander output shaft 38.

The supporting structure 40 supports the main components of the Rankine system 30, and possibly at least some of the above-mentioned additional components, and is configured for being mounted on the vehicle chassis 3. For example, as shown in figures 1 and 3, the supporting structure 40 can be mounted on a longitudinal beam 6 of the chassis 3. The waste heat recovery assembly 20 can thus be designed as an add-on system that can be retrofitted to conventional vehicles without requiring significant changes.

The supporting structure 40 comprises a bracket to which are attached all main components 32-36.

Typically, the bracket can be made of aluminium or stainless steel. It could be a cast-iron bracket as well. In the preferred illustrated embodiment, the supporting structure may consist of said bracket 40 as a single supporting member. The bracket 40 preferably extends substantially transversally in the mounted position.

As shown in figures 6 and 7, the supporting structure 40 comprises an interface 45 for mounting the waste heat recovery assembly on the chassis 3. The interface 45 may comprise, or consist in, a substantially vertical and longitudinal board. Elements located closer to the interface 45, i.e. closer to the vehicle chassis 3 in the mounted position, are referred to as “inner” as compared to elements located further from the interface 45, which are referred to as “outer”.

The bracket 40 comprises a main wall 46 which is substantially vertical and transversal, i.e. parallel to (Y,Z) when the waste heat recovery assembly 20 is installed on the chassis 3. The main wall 46 can have a lower portion 47 and an upper portion 48. Each of the lower portion 47 and upper portion 48 may be substantially flat. The lower portion 47 and upper portion 48 may be offset relative to one another along the longitudinal direction X, by a fairly small distance, for example less than 20 cm. A horizontal panel 49 can be provided between the lower portion 47 and upper portion 48 of the bracket main wall 46, for stiffening the structure. The length of the upper portion 48 - from the interface 45 and along the transverse direction Y - may be smaller than the length of the lower portion 47.

In this exemplary embodiment, the main wall 46, and thus the bracket 40, has opposite first and second sides which are respectively a front face 41 and a rear face 42, with regard to the longitudinal direction X.

The bracket 40 may further comprise at least one panel orthogonal to the main wall 46 and configured to reinforce the bracket 40 and/or to form an attachment member for one of the Rankine system components. For example, there may be provided a lower horizontal panel 51 secured to the main wall lower portion 47 on its inner end portion, and/or a vertical longitudinal panel 52 secured to the outer portions of the main wall lower portion 47 and of the horizontal panel 49. Besides, there may be provided a frame 53 arranged parallel to a plane (X,Z) in an outer notch 54 of the main wall upper portion 48, the frame 53 being secured to both the main wall upper portion 48 and to the horizontal panel 49. The frame 53 may receive the recuperator 43. The bracket 40 can include bearing structures for the Rankine system components, as well as holes 55 for receiving fasteners, and openings 56 for receiving connecting elements between the Rankine system components. In particular, pipes 22, 23, 25, 26, 27 may pass through some of these openings 56. The notch 54 can be one of these openings 56.

The tank 32, pump 36, expander 34 and condenser 35 - i.e. all main components of the Rankine system 30 except the heat exchanger 33 - can be secured to the front face 41 or to the rear face 42 of the bracket main wall 46.

As illustrated in the non-limiting embodiment of figures 3 to 5:

- the condenser 35 may be secured to the rear face 42, on the main wall lower portion 47;

- the pump 36 may be secured to the rear face 42, on the main wall upper portion 48;

- the tank 32 may be secured to the front face 41 , on the main wall upper portion 48, for example opposite the pump 36;

- the expander 34 may be secured to the front face 41 , on the main wall upper portion 48, for example substantially along a same transverse axis as the tank 32.

In other words, according to this non-limiting embodiment: the expander 34 and the tank 32 are secured to the same face, namely the front face 41, while the pump 36 and the condenser 35 are secured to the same opposite face, namely the rear face 42.

The heat exchanger 33 may be arranged substantially vertically and longitudinally. It may be secured to the interface 45, lower horizontal panel 51 and/or horizontal panel 49 by means of mounting members 57 and fasteners 58.

On the bracket 40 may further be secured additional components.

The electric motor 39 can be secured to the bracket 40 on the side opposite the expander 34, here on the rear face 42. The electric motor 39 can be connected to the expander 34 by means of a belt 59 received in an opening 56a of the bracket 40.

The fan 44 can be secured to the bracket 40 in order to face the condenser 35, on the side opposite the condenser 35, here on the front face 41. An opening 56b may be provided in the bracket 40 for allowing air to flow from the fan 44 to the condenser 35. Furthermore, a shroud 60 may be provided between a fan outer ring 61 and the bracket 40. The shroud 60 may be secured to the fan outer ring 61 and to the front face 41 by means of peripheral fasteners 58.

Basically, the main components are attached to the bracket 40 using fasteners such as bolts 58 and mounting members 57. In a variant not shown, any other fastening means (rivet, screws and the like) could be used to attach the main components of the Rankine system to the bracket 40.

The filter 28 may be secured to the rear face 42, on the main wall lower portion 47 or on the vertical longitudinal panel 52, for example close to an outer edge of the condenser 35.

The waste heat recovery assembly 20 defines a virtual envelope 70 which is the box shaped housing that encloses the whole waste heat recovery assembly 20 as close as possible, i.e. with its faces being tangent to the waste heat recovery assembly 20. As shown in figure 3, the virtual envelope 70 has a parallelepiped shape having faces which, in the mounted position, comprise:

- an upper face 73 and a lower face 74 which are substantially horizontal;

- a front face 71 and a rear face 72 which are substantially orthogonal to the longitudinal direction;

- an internal side face 75 and an external side face 76 which are substantially orthogonal to the transverse direction.

The upper, lower, front, rear, internal and external face respectively include the uppermost, lowermost, most forward, most rearward, most inward and most outward point of the waste heat recovery assembly 20.

More specifically, the upper face 73 may include the upper edge 62 of the interface 45 and/or upper face 63 of the bracket main wall 46, wherein said edges 62, 63 may be located in a same horizontal plane. The lower face 74 may include the lower face 64 of the bracket lower horizontal panel 51. The front face 71 may include the front end 65 of the heat exchanger 33. The rear face 72 may include the rear end 66 of the heat exchanger 33. The internal side face 75 may include the inner face 67 of the heat exchanger 33. The external side face 76 may include the outer face 68 of the bracket vertical longitudinal panel 52, and/or the outer edge 69 of the lower portion 47 of the bracket main wall 46, wherein said outer face 68 and said edge 69 may be located in a same vertical plane. This envelope 70 is virtual, meaning that it does not form a housing having walls formed by structural members which may allow supporting the Rankine system components. On the contrary, at least one face of the virtual envelope 70 is fully open, which means that said face has no wall, no peripheral edge, no inner beam joining edges of said face.

In particular, at least the front face 71 and the rear face 72 of the virtual envelope 70 may be fully open. In other words, the supporting structure 40 does not include front and side brackets on which components of the Rankine system 30 may be secured and which may respectively form the front and rear walls of a housing. On the contrary, the supporting structure only includes the bracket 40, which is located within the virtual envelope 70, parallel to but at a distance from the front face 71 and the rear face 72.

As shown in figure 3, all faces 71-76 of the virtual envelope 70 may be fully open. As previously described, some of these faces 71-76 may however include a portion of the bracket 40, such as an edge thereof.

Another embodiment of the invention is shown on figures 8 to 10.

Figure 8 schematically shows the chassis 3 of a vehicle 1. An Exhaust After-Treatment System (EATS) 80 is provided for treating the exhaust gases produced in the engine 7 before they are released into the environment. The EATS 80 comprises a casing that is secured to one of the two longitudinal beams 6 of the chassis 3, for example to the beam 6 that supports a fuel tank 81 as well. The EATS 80 can be mounted on the beam 6 by means of a support member 83 secured to said beam 6.

The supporting structure 40 of the waste heat recovery assembly 20 can be mounted on the casing of the EATS 80. Typically, in this variant, the EATS casing would include a mechanical interface for attaching the supporting structure 40 of the Rankine system 30. Therefore, the Rankine system 30 is indirectly attached to the chassis 3 through the EATS 80, as it can be seen in figure 9. In other words, in this embodiment, the waste heat recovery assembly 20 is indirectly mounted on the chassis 3, as it is mounted on the EATS 80 which, itself, is mounted on the chassis 3. The supporting structure 40 of the waste heat recovery assembly 20 can be mounted on the EATS casing or on the EATS support member 83, through an appropriate interface. In the embodiment of figure 9, the bracket 40 is not secured to the support member 83 by means of fasteners, but by means of a “hook and hang”-type system, through which the bracket can hang from the EATS casing or the EATS support member 83.

Typically, the bracket 40 of the Rankine heat recovery system 30 is supported by another bracket 83 which is attached to the beam 6, for example bolted to the beam 6. This provides the advantage that the Rankine system 30 can be removed from the vehicle without having to remove any fastener. This is quite practical to perform maintenance operations or repair.

Advantageously, brackets 40 and 83 include a mechanism (not shown) to prevent the bracket 40 from moving relative to the bracket 83 bolted to the beam 6. Such mechanism is known as such, that is why it is not represented on the figures.

Besides, as illustrated in figure 8, the main components of the Rankine system 30, or even all components of the Rankine system 30, can be attached to the bracket 40 on one and the same face of said bracket 40, opposite the EATS 80.

Such an arrangement of the components on a single face of the bracket 40 could also be implemented in the embodiment of figures 2-5.

In correspondence with figure 10, another advantage of the invention is that the bracket 40 can have a thickness high enough - preferably in the longitudinal direction X - to delimit one or more channels for the passage of fluid. In a variant not shown, such channel could be used to pass electric cable(s) as well.

In a preferred embodiment, the channel then replaces one or more of the pipes 22, 23, 25, 26, 27 of the Rankine system 30, as shown on figure 10. Typically, one connector is provided at each end of the channel to connect the channel to one of the components of the Rankine system 30.

In this particular embodiment, in which the bracket 40 delimits one or more channels, the bracket is preferably a cast-iron bracket. Such arrangement of the channels inside the bracket, is advantageous in that it allows avoiding the use of a pipe between a pair of components of the Rankine system.

Reference is now made to figure 11 , which shows another embodiment of the invention.

In this embodiment, the waste heat recovery assembly 20 is mounted on the chassis 3 between the two longitudinal beams 6. As compared to the previously described embodiments, in which the waste heat recovery assembly 20 is mounted on an outer face of one beam 6, this provides a higher protection to the waste heat recovery assembly 20, especially in the event of a collision.

With such an implementation, the bracket 40 and components of the Rankine system are configured to allow the propulsion shaft 11 to pass from the engine 7 to the wheels 4. To that end, the bracket 40 may have a central hole for the passage of the propulsion shaft 11.

Having a single bracket to which are attached all Rankine system main components, and possibly all Rankine system components, and arranged in an open environment, allows greatly reducing weight and improving both compactness and accessibility. It is to be understood that the present invention is not limited to the embodiments described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims.

Claims

1. A waste heat recovery assembly (20) for a vehicle (1), the waste heat recovery assembly (20) comprising:

- a Rankine system (30) including a set of main components, namely a tank (32), a pump (36), a heat exchanger (33), an expander (34) and a condenser (35), connected by pipes (22, 23, 25, 26, 27) for carrying a working fluid;

- a supporting structure (40) which supports at least said main components of the Rankine system (30), the supporting structure (40) having an interface (45) for mounting the waste heat recovery assembly (20) on a chassis (3) of the vehicle (1); characterized in that the supporting structure is a bracket (40) to which are attached all main components (32-36).

2. The waste heat recovery assembly according to claim 1, characterized in that the bracket (40) comprises a main wall (46) which is substantially vertical and transversal when the waste heat recovery assembly (20) is mounted on a vehicle chassis (3).

3. The waste heat recovery assembly according to claim 2, characterized in that all main components (32, 34, 35, 36) of the Rankine system (30), except the heat exchanger (33), are secured to the front face (41) or to the rear face (42) of the bracket main wall (46).

4. The waste heat recovery assembly according to any one of claims 1 to 3, characterized in that the heat exchanger (33) is arranged substantially vertically and longitudinally.

5. The waste heat recovery assembly according to any one of claims 1 to 4, characterized in that the interface of the supporting structure (40) comprises a substantially vertical and longitudinal board (45), when the waste heat recovery assembly (20) is mounted on a vehicle chassis (3).

6. The waste heat recovery assembly according to any one of claims 1 to 5, characterized in that the bracket (40) includes bearing structures for the Rankine system components, holes (55) for receiving fasteners (58), and openings (54, 56) for receiving connecting elements (22, 23, 25, 26, 27, 59) between the Rankine system components.

7. The waste heat recovery assembly according to any one of claims 2 to 6, characterized in that the bracket (40) comprises at least one panel (49, 51, 52, 53) orthogonal to the main wall (46) and configured to reinforce the bracket (40) and/or to form an attachment member for one of the Rankine system components.

8. The waste heat recovery assembly according to any one of claims 1 to 7, characterized in that at least one additional component is attached to the bracket, said additional component being chosen among:

- a fan (44); - an electric motor (39);

- a filter (28) for the working fluid; and

- a recuperator (43).

9. The waste heat recovery assembly according to any one of claims 1 to 8, characterized in that the overall dimensions of the waste heat recovery assembly (20) are:

- height: less than 710 mm;

- width: less than 760 mm;

- length: less than 400 mm.

10. The waste heat recovery assembly according to any one of claims 1 to 9, characterized in that the bracket (40) delimits at least one channel for the passage of fluid or of electric cable(s).

11. The waste heat recovery assembly according to claim 10, characterized in that the bracket (40) delimits at least one recess for receiving a seal ring, said recess being formed around one end of a fluid channel.

12. The waste heat recovery assembly according to any one of claims 1 to 11, characterized in that the bracket includes at least one boss to which is attached a sensor, for example a pressure or a temperature sensor.

13. A vehicle (1) comprising a chassis (3), an internal combustion engine (7) installed on the chassis (3) and an exhaust line (15) capable of collecting exhaust gases from said engine (7), characterized in that it further comprises a waste heat recovery assembly (20) according to any one of the preceding claims, the waste heat recovery assembly (20) being mounted on the vehicle chassis (3), wherein the working fluid of the Rankine system (30) can be successively evaporated in the heat exchanger (33) by heat exchange with the exhaust gases, expanded in the expander (34), condensed in the condenser (35) and compressed in the pump (36).