ADDITIONAL PROPULSION METHOD AND SYSTEM FOR A VEHICLE

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims priority from Italian patent applications no. 102024000026967 and No. 102024000026970 both filed on Nov. 28, 2024, the entire disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The invention relates to an additional propulsion method and system for a vehicle.

PRIOR ART

It is known that a vehicle with an endothermic engine comprises an exhaust system, which is configured to treat and release exhaust gases. Furthermore, endothermic engines are designed so as to reduce polluting emissions by acting upon the stoichiometric fuel/oxidizer ratio. This, however, can lead to extremely high temperatures in the exhaust gases. In particular, known solutions suffer from the drawback that the temperatures reached by the exhaust gases can cause the deterioration of the exhaust system and/or of other components of the vehicle exposed to the heat of the exhaust gases.

Furthermore, known solutions entail the dispersion of the heat of the exhaust gases in the environment.

DESCRIPTION OF THE INVENTION

The object of the invention is to provide a propulsion system that makes it possible to overcome the drawbacks described above.

According to the invention, there are provided a propulsion method, a propulsion system and a vehicle as set forth in the appended claims.

The dependent claims define special embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Hereinafter, embodiments of the invention will be described, in order to allow the latter to be better understood, by way of non-limiting example and with reference to the accompanying drawings, wherein:

FIG. 1 is a schematic view, with some parts removed for greater clarity, of a vehicle with a propulsion system according to the invention;

FIGS. 2 and 3 are perspective views of a detail of a propulsion system according to the invention;

FIG. 4 is a schematic view, with some parts removed for greater clarity, of a further detail of a propulsion system according to the invention;

FIGS. 5 and 6 schematically show, in a partially sectional view, a detail of FIG. 4 in respective different operating configurations.

EMBODIMENTS OF THE INVENTION

In FIG. 1, reference number 1 is used to indicate, as a whole, a vehicle comprising, in a known manner: a bearing structure 2 (for example, a body shell and/or a frame), which defines a passenger compartment 3 configured to accommodate at least one driver and possibly one or more passengers; and a body 4, which externally covers the bearing structure 2.

As it is known, the vehicle 1 has: a longitudinal axis X, generally known as the roll axis; a transverse axis Y, generally known as the pitch axis; and a vertical axis Z, generally known as the yaw axis.

The vehicle 1 can rotate-translate, in a known manner, on a horizontal support plane π. The terms “front”, “rear”, “right”, “left”, “upper”, “lower”, “upstream”, “downstream” and others similar to them are used with reference to the vehicle 1 moving on the support plane π in the forward direction v. The terms “outer”, “inner” and others similar to them are used with reference to the passenger compartment accommodating the driver of the vehicle 1 while driving.

The vehicle 1 comprises an endothermic engine 5 (of the known kind and schematically shown), the type of engine 5 being variable. According to the example shown, the engine 5 is a rear engine, without lacking generality, and, according to a variant which is not shown, the engine 5 can be a front engine. The vehicle 1 further comprises an exhaust system 10 and a propulsion system 6 according to the invention.

The exhaust system 10 comprises a manifold 7 configured to be connected, in a known and schematically shown manner, to the engine 5 in order to receive the exhaust gases g flowing out of the engine 5. In particular, the manifold 7 comprises one or more inlets 8, each of which is configured to be connected to a respective outlet (not shown) for exhaust gases g of the engine 5. The number, type and size of the outlets 8 are variable. The manifold 7 further comprises an outlet 9, which is configured to be connected (in a known and schematically shown manner) to further components of the exhaust system 10. By mere way of example, the manifold 7 is connected to an exhaust line 10 (along which known components such as: catalytic converters, silencers, filters, which are not shown herein, can be installed), which communicates with the outside through a terminal 11 (schematically shown) to allow exhaust gases g to flow out.

The shape and size of the manifold 7 are variable. The manifold 7 is delimited by an outer surface 12.

Advantageously, the manifold 7 is also part of the propulsion system 6. In particular, the propulsion system 6 comprises a plurality of fins 14, each of which protrudes from a respective portion of the outer surface 12 of the manifold 7. Each fin 14 is a thin body; in other words, each fin 14 has two dimensions (width and length) that are significantly greater than a third dimension (thickness). The shape and size of each fin 14 are variable. Each fin 14 can be manufactured as one single piece together with the manifold 7 or can be connected to the manifold 7.

The fins 14 are configured to increase the exchange surface of the manifold 7 and to permit the extraction of as much thermal power as possible, as explained more in detail below.

Each fin 14 can be made of the same material as the manifold 7 or of a different material.

According to the example shown in FIGS. 2 and 3, the propulsion system 6 comprises a group of fins 14I, which are parallel to a plane π1, in particular perpendicular to the plane XZ. The propulsion system 6 further comprises a group of fins 14II parallel to a plane π2, in particular perpendicular to the plane XY.

The number and mutual arrangement of the fins 14 of a same group of fins 14I, 14II are variable.

Without lacking generality, the fins 14 can be arranged in different configurations with respect to the examples shown, for example the fins 14 of each group of fins 14I, 14II can be inclined relative to one another and each have their own arrangement independent of the others.

According to the example shown, the fins 14 of a group of fins 14I, 14II are parallel to the same reference plane π1, π2 and are mutually arranged so as to delimit, as described more in detail below, ducts 15. Hereinafter, the ducts 15I are the ducts delimited by the group of fins 14I and, similarly, the ducts 15II are the ducts delimited by the group of fins 14II.

The number and mutual arrangement of the ducts 15i, 15II are variable.

According to the example shown in FIG. 1, the fins 14 of the group of fins 14I are parallel to the support plane π, in other words they are horizontal; and the fins 14 of the group of fins 14II are perpendicular to the support plane π, in other words they are vertical.

Hereinafter, the finned exchanger 16 indicates the assembly formed by the manifold 7 and the fins 14.

According to a variant which is not shown herein, the manifold 7 can be devoid of fins 14.

Advantageously, the propulsion system 6 further comprises a conduit 18. The conduit 18 is a tubular body having an inner through cavity 19, which faces outwards through a front air intake 20 and a rear outlet 21. The air intake 20 faces the front portion of the vehicle 1 and is configured to channel an air flow f hitting the vehicle 1, in particular when the vehicle 1 is running, into the cavity 19.

Advantageously, the conduit 18 is configured to direct an air flow f against the manifold 7. In particular, the manifold 7 is installed inside the conduit 18 in the area of a heat exchange section 26. The manifold 7 is not in fluid communication with the conduit 18. In other words, the exhaust gases g flowing through the manifold 7 do not mix with the air flow f. According to the example shown, the manifold 7 transversely crosses the cavity 19. The conduit is tightly sealed on the manifold 7, so that the inlets 8 and the outlet 9 are arranged on the outside of the conduit 18. The conduit 18 is sealed with a sealed connection 40 around the outlet 9 (FIGS. 4 to 6) and with respective sealed connections (not shown) around each respective inlet 8. In this way, in the area of the heat exchange section 26, passages for the flows of two fluids (the flow of exhaust gases g and the flow of air f) are obtained, which are physically separate from each other.

The heat exchange section 26 of the conduit 18 is configured to surround, preferably without contact, the manifold 7. In particular, the heat exchange section 26 is configured to laterally delimit, together with the fins 14I, 14II of the manifold 7, the ducts 15I, 15II and to obtain mandatory paths for the air flow f. Advantageously, the ducts 15I, 15II are configured to obtain, in certain areas of the manifold 7, laminar air flows f.

According to the example shown in FIGS. 1 and 4, the conduit 18 has an intermediate section 22, along which the cavity 19 has a variable cross-section. In particular, the cross-section of the cavity 19 of the intermediate section 22 decreases from the air intake 20 towards the manifold 7. In particular, the intermediate section 22 is configured to generate a Venturi effect and increase the speed and pressure of the air flow f. The presence of the intermediate section 22 upstream of the manifold 7, with respect to the travel direction v of the vehicle 1, makes it possible to increase the thermal efficiency of the propulsion system 6, as explained more in detail below. The shape and size of the intermediate section 22 are variable.

According to the example shown in FIGS. 1 and 4, the intermediate section 22 is divided into two portions, which are inclined relative to each other and are hereinafter identified with: upward portion 24 and downward portion 25. The downward portion 25 is interposed between the upward portion 24 and the heat exchange section 26. The mutual inclination between the upward portion 24 and the downward portion 25 is variable.

The shape and size of the conduit 18 are variable and are related to the overall layout of the vehicle 1.

Advantageously, the conduit 18 comprises a terminal section 23, which is interposed between the heat exchange section 26 and the outlet 21. The cavity 19 of the terminal portion 23 has an increasing cross-section from the heat exchange section 26 towards the outlet 21.

Advantageously, the terminal section 23 is configured to selectively vary its passage cross-section, so as to form a nozzle with a variable cross-section. In particular, according to the example shown in FIGS. 5 and 6, the conduit 18 comprises a movable flap 27, which is installed inside the cavity 19 and is hinged to the conduit 18. The movable flap 27 can selectively rotate from an opening position P1 to a closing position P2 and vice versa. Without lacking generality, the shape and size of the movable flap 27 are variable. The movable flap 27 can be constrained to the conduit 18 according to a connection method chosen from a group of connections that are different in terms of type (for example, it can be connected to the conduit by means of a translating, rotating-translating system).

The propulsion system 6 further comprises a control unit 28, which is configured to selectively adjust the position of the movable flap 27.

An additional propulsion method according to the invention is described below.

In use, during the travel of the vehicle 1, the engine 5 produces exhaust gases g that are collected, in a known manner, by the manifold 7 and conveyed, through the manifold 7, along the exhaust system 10 and out through the terminal 11. At the same time, the vehicle 1, moving in the direction v, is hit by an air flow f, which is conveyed, through the air intake 20, into the conduit 18.

The conduit 18 directs the air flow f through the heat exchange section 16. Advantageously, the particular shape of the conduit 18 upstream of the heat exchange section 26 makes it possible to obtain an air flow f entering the heat exchange section 26 with certain characteristics (speed, pressure, inclination).

Through the heat exchange section 16, the air flow f flows in contact with the heat manifold 7 and heats up. This can be done both with a manifold 7 without fins and with a finned manifold 7, namely having a plurality of fins 14I, 14II.

Advantageously, the presence of the fins 14I, 14II allows the air flow f to be channelled in laminar flows, especially in the area of given zones. This increases the efficiency of the heat exchange.

By flowing through the heat exchange section 26, the air flow f heats up and the exhaust gases g inside the manifold 7 cool down. In this way, advantageously, it is possible to contain the temperatures of the engine 5, of the manifold 7 and of the exhaust system 10 in general and it is therefore possible to increase the stoichiometric ratio so as to reduce polluting emissions, maintaining the same power or increasing the power with respect to a rich mixture.

At the exit of the heat exchange section 26 there is a flow of hot air f. The air flow f, by heating up, accelerates.

The hot air flow f flows through the terminal section 23 before being discharged to the outside.

The terminal section 23, in combination with the movable flap 27, forms an exhaust nozzle, which exploits the enthalpy change in the air flow f between the position upstream and downstream of the conduit 18 so as to obtain a propulsion effect for the vehicle 1.

Advantageously, by varying the position of the movable flap 27, it is possible to adjust the passage cross-section of the air flow f at the outlet, so as to maximise the propulsion effect of the hot air flow f, as a function of the instantaneous running conditions of the vehicle 1. Advantageously, both the terminal section 23 and the movable flap 27 are shaped so as to make the most of the propulsion effect of the enthalpy change that is generated downstream of the heat exchange section 26.

Advantageously, the propulsion system 6 described above allows the exhaust gases g to be cooled and, therefore, the peak temperatures thereof to be lowered, allowing the stoichiometric ratio of the engine 5 to be increased.

Advantageously, the propulsion system 6 described above makes it possible to obtain an energy recovery thanks to the use of the enthalpy change in the air flow f to generate an additional propulsion thrust.