FR3063523A1 - MOTOR POWERTRAIN WITH INTERNAL COMBUSTION ENGINE - Google Patents

Abstract

Power train comprising a thermal engine (2), an air supply circuit (3) for said engine (2), a motor coolant circuit (16) (2) and a fan (7), said circuit ( 3) supplying air to the engine (2) comprising a compressor (4) and a radiator (5), said radiator (5) to air inside which the compressed air by the compressor (4) is adapted to circulating to be cooled there being disposed between the compressor (4) and the intake (6) of the air intake of the engine (2) and close to the fan (7) to be disposed at least partially in the flow of air produced by the fan (7). At least a portion of the engine coolant circuit (16) forms, with at least a portion of the portion (31) of the engine air supply circuit (3) disposed between the compressor (4) and the air radiator (5), an air / liquid heat exchanger (20).

Description

FIELD OF THE INVENTION

The invention relates to a powertrain with a supercharged internal combustion engine.

It relates more particularly to a powertrain comprising a heat engine, an air supply circuit for said engine, an engine coolant circuit and a fan, said engine air supply circuit comprising a compressor and a radiator. , said air radiator, inside which the air compressed by the compressor is able to circulate in order to be cooled therein, being arranged between the compressor and the engine air intake inlet and, near the fan , to be placed in the air flow produced by the fan.

PRIOR ART

A large number of cooling systems for the combustion engine charge air, also called an internal combustion engine, are known. This charge air that feeds the engine air intake is compressed air by a compressor driven indirectly via a turbine by the exhaust or directly by the engine. Such cooling of the charge air, upstream of the engine air intake inlet, makes it possible to reduce the volume of compressed air and thus increase the density of the charge air arriving at the engine. . Existing cooling systems are characterized by their complexity and size. Cooling is often carried out using the air radiator located on the air intake circuit. This air radiator forms an air / air heat exchanger with the ambient air, making it necessary to oversize said radiator.

GOALS AND SUMMARY

An object of the invention is to provide a powertrain whose design allows a reduction in the dimensions of the air radiator of the engine air intake circuit without adversely affecting the efficiency of said cooling.

To this end, the subject of the invention is a powertrain comprising a heat engine, an air supply circuit for said engine, an engine coolant circuit and a fan, said engine air supply circuit comprising a compressor and a radiator, said air radiator inside which the air compressed by the compressor is able to circulate in order to be cooled therein being disposed between the compressor and the engine air intake inlet of the fan to be arranged at least partially in the air flow produced by the fan, characterized in that at least a portion of the engine coolant circuit forms with at least a portion of the portion of the supply circuit in air from the engine arranged between the compressor and the air radiator an air / liquid heat exchanger.

The use of engine coolant for heat exchange with the charge air allows efficient cooling of said air.

According to one embodiment of the invention, the part of the portion of the engine air supply circuit disposed between the compressor and the air radiator and forming an air / liquid heat exchanger with a portion of the coolant circuit , is formed by a plurality of parallel braced tubes, inside which the air coming from the compressor is able to circulate from one of the ends called air intake towards the other end called d air exhaust from each tube, said tubes and their spacers being housed inside a tubular envelope delimiting with the spacers, disposed axially offset along the tubes, a chamber provided with an inlet and a fluid circulation outlet arranged on the coolant circuit for supplying coolant to said enclosure.

This results in a reduced overall dimensions and an ease of implementation without disturbing the circulation of the air flow.

Preferably, each spacer assumes the shape of a plate provided with through orifices each housing, in an airtight manner, the end of a tube, the tubular casing assumes the shape of an elongated hollow body and îo the tube / spacer assembly is immobilized axially inside said envelope by airtight coupling of the spacers, preferably at the external peripheral edge of the spacers, to the internal face of the component body of the tubular casing.

This results in a perfect seal of the enclosure at the level of the spacer / tubular casing and spacers / tubes connection.

According to an embodiment of the invention, the tubular envelope which is an elongated hollow body is provided externally with fins.

The presence of fins makes it possible to increase the exchange surface and to use the air flow of the fan as an additional cooling means.

Preferably, the fins affect the shape of parallel circular external radial turns or flanges extending over at least part of the periphery of the envelope.

According to one embodiment of the invention, the inlet and the outlet for circulation of fluid of the enclosure delimited by the envelope and the spacers are respectively provided one, at the air exhaust ends of the the other, at the air intake ends of the tubes, to allow, inside said enclosure, a circulation of the coolant and the air against the current.

According to one embodiment of the invention, said enclosure is positioned at the periphery of the fan.

This positioning of the enclosure allows it to receive a larger mass of air from the fan.

According to one embodiment of the invention, the powertrain comprises a thermostat or a sensor for measuring a parameter representative of the temperature of the air in the air supply circuit of the engine, and the portion of the liquid circuit. cooling arranged between the engine and the fluid circulation inlet of the enclosure delimited by the casing and the spacers is provided with a controllable shutter member mounted movably between a closed position and an open position according to the data of measured temperature.

This results in the possibility of regulating the flow rate of the coolant flow to avoid excessive cooling of the charge air flow.

The invention also relates to a self-propelled rolling vehicle characterized in that it comprises a powertrain of the aforementioned type.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be clearly understood on reading the following description of exemplary embodiments, with reference to the appended drawings in which:

FIG. 1 represents a partial schematic view of a powertrain,

FIG. 2 represents a diagram of the various fluid flows within the powertrain,

FIG. 3 represents a perspective view of the air / liquid heat exchanger, part of the casing not having been shown to allow the interior of the exchanger to be viewed,

FIG. 4 represents an exploded position view of the elements making up the air / liquid heat exchanger, and

FIG. 5 represents in the form of two detailed views each of the ends of the air / liquid heat exchanger.

DETAILED DESCRIPTION

As mentioned above, the subject of the invention is a powertrain 1 which includes an internal combustion engine 2. This engine 2 has an air intake inlet 6 and an exhaust manifold 22 for the gases leaving the engine 2. These gases arrive via a suitable pipe for a turbine 41 of a turbo-compressor 4. The gases exhaust rotate the turbine 41, before being discharged into the atmosphere by an outlet pipe via a pollution control system. The turbine 41 rotates the rotor of the compressor 4 mounted integral in rotation with the turbine 41. The rotor of the compressor 4 sucks, during its rotation, the ambient air by a pipe equipped with an air filter. The compressor 4 compresses this air to discharge it, via an air supply circuit 3, to the engine air intake inlet 6. Equivalently, the engine intake air can be sent to the engine by a compressor directly driven by the engine. The air supply circuit 3, which is represented by a line and dots in FIG. 2, comprises, between the compressor 4 and the air intake inlet 6 of the engine 2, an air radiator 5. This air radiator 5 is disposed near a fan 7 capable of passing ambient air along the radiator to increase the cooling efficiency of the radiator 5 which forms with the air flow from the fan an air / air exchanger . This radiator 5 is in the form of vertical tubes connected at the inlet to an air inlet manifold and at the outlet to an air outlet manifold. The tubes are separated from each other by fins. The charge air circulates in the tubes. Ambient air flows through the fins and cools the wall of the tubes. This radiator 5 is called a cross-current heat exchanger.

The powertrain 1 further includes a circuit 16 for engine 2 coolant which includes a radiator 161 and a pump (not shown). In operation, the engine 2 drives the pump which circulates the coolant, such as water or an aqueous solution, between the engine 2 and the radiator 161. This coolant circuit 16 is represented by a dash and crosses in Figure 2. The coolant sent to engine 2 absorbs heat and returns to the radiator. The heat collected by the coolant is dissipated in the ambient air by the radiator 161 in itself. A fan 7, which is preferably the same as that arranged near the air radiator 5 of the air supply circuit 3, passes ambient air along the radiator 161 to increase the cooling efficiency of the radiator 161 which forms with the air flow from the fan an air / air exchanger.

According to the invention, at least part of the portion 31 of the air supply circuit 3 of the engine 2 disposed between the compressor 4 and the air radiator 5, with a portion of the circuit 16 of the engine coolant 2, an air / liquid heat exchanger. The part of the portion 31 of the air supply circuit 3 of the engine 2 disposed between the compressor 4 and the air radiator 5 and forming an air / liquid heat exchanger 20 with a portion of the coolant circuit 16, is formed of a plurality of tubes 8 braced, parallel, inside which the air from the compressor 4 is able to circulate from one of the ends called air intake and shown at 9 in the figures of each tube 8 , in the direction of the other end called the air exhaust and represented at 10 of each tube 8. These tubes 8, which in the example shown are eight in number, and their spacers 11 which are two in number , are housed inside a cylindrical tubular casing 12. These tubes can be of any cross section, namely, round, square, ovoid or the like, although a circular cross section is preferred. This cross section of the tubes may or may not be constant from one end to the other of the tubes. The surface of each tube can be smooth or present deformations or occasional additions of material capable of allowing optimization of heat exchanges. The set of tubes 8 / spacers 11 / casing 12 thus forms a section of the circuit 3 for supplying air to the engine between the compressor 4 and the air radiator 5. This assembly is connected to the rest of the engine air supply circuit to, and in particular to conduits constituting the engine air supply circuit, at the ends of the casing. Thus, one duct connects one end of the casing 12 to the outlet of the compressor 4 while another duct connects the other end of the casing 12 to the inlet of the air radiator 5. Continuity of air circulation between the outlet of the compressor 4 and the radiator 5 via the tubes 8 is therefore ensured. To ensure such fluid continuity, the envelope 12 / tubes 8 / spacers 11 assembly is produced as follows. The spacers 11 are arranged axially offset along the tubes 8. Each spacer 11 takes the form of a plate provided with through orifices each housing airtight the end of a tube 8. There therefore has as many through holes as there are tubes. Each tube is held at each of its ends, generally by welding inside a hole passing through one of the plates in a position in which the end of the tube is placed flush with the plate. The weld ensures a seal at the space between the tube and the orifice. Thus, the plates arranged at each of the ends of the tubes keep the tubes in parallel arrangement. This tube / spacer assembly, as shown in FIG. 4, can be threaded inside the tubular casing 12 which has the shape of an elongated hollow body. The set of tubes 8 / spacers 11 is immobilized axially inside said envelope 12 by coupling of the spacers 11 to the internal face of the body constituting the tubular envelope. This coupling takes place by welding the external circumferential edge of the plates constituting the spacers 11 to said internal face of the body constituting the tubular casing 12. Again, this coupling makes it possible to obtain an air tightness between the plates and the casing. Thus, the plates constituting the spacers 11, in the fixed state of the tubes 8 on the spacers 11 and immobilized by the set of spacers 11 / tubes 8 inside the envelope 12, form, with said envelope 12, a enclosure 13. This enclosure 13 is provided with an inlet 14 and an outlet 15 for circulation of fluid which are respectively formed by a through opening formed in the envelope 12. The inlet 14 and outlet 15 for circulation of fluid of the enclosure therefore form a radial inlet and outlet of the enclosure 13, the longitudinal axis of which extends parallel to the longitudinal axis of the tubes 8. These inlet 14 and outlet 15 for circulation of fluid from the enclosure are arranged on the coolant circuit 16 for supplying coolant to the enclosure 13. In particular, the coolant circuit 16, as described above, comprises, on the portion of the circuit 16 for cooling the supply of coolant from the engine 2 to the radiator 161, a division of the circuit into two branches which join downstream of the radiator 161. One of the branches on which the enclosure 13 described above is arranged , supplies coolant to the enclosure 13 thus traversed by the coolant. The other branch, on which the radiator 161 is arranged, supplies the radiator.

In the example shown, the power train 1 comprises a sensor 18 for measuring the air temperature of the circuit 3 for supplying air to the engine 2 at the inlet 6 of the heat engine 2 and the portion of the circuit 16 of cooling disposed between the motor 2 and the inlet 14 for circulation of fluid from the enclosure 13 delimited by the casing 12 and the spacers 11 is provided with a shutter member 19, in this case a controllable solenoid valve, mounted movable between a closed position and an open position according to the measured temperature data. This shutter member 19 is disposed between the point of division of the circuit 16 of coolant into two branches and the inlet 14 of the enclosure 13 to allow at will a supply of coolant to the enclosure 13 in function of the measured temperature.

It is noted that, in the example shown, the inlet 14 and the outlet 15 for circulation of fluid from the enclosure 13 containing the tubes 8 and delimited by the casing 12 and the spacers 11 are respectively arranged one at level 10 of the air exhaust ends of the tubes, the other, at the ends 9 of the air intake of the tubes, to allow, inside said enclosure 13, a circulation of the coolant and counter current air. These inlet 14 and outlet 15 for circulation of fluid from the enclosure 13 are obviously disposed within the interval delimited by the spacers 11. Thus, inside the enclosure 13, the air circulates in the tubes 8 from the air intake end 9 of the tubes to the air exhaust end 10 of the tubes 8, while the coolant circulates outside the tubes 8, along the tubes 8, from the air exhaust end 10 to the air intake end 9.

To help cool the casing 12, the latter which is an elongated hollow body is provided externally with fins 17. These fins affect the shape of parallel circular external radial turns or flanges extending, in the example shown, to some, on a part of the periphery of the envelope, for others, on the entire periphery of the envelope. The envelope 12 and the enclosure 13 which it delimits are positioned at the periphery of the fan 7 in order to make the most of the flow of cooling air coming from the fan 7. In fact, the fan has, at its central zone , reduced air flow. Thus, the fan being considered to be inscribed in a cylinder of radius R and of center O placed on the axis of rotation of the fan, the casing 12 and the enclosure 13 which it delimits are arranged inside said cylinder and are spaced from the center O of the cylinder by a distance at least equal to a third, preferably at least equal to half the radius, more preferably at least equal to 0.75 times the radius of said cylinder. Thus, in the example shown, the casing 12 is ίο disposed on one side, that is to say along one of the faces of the fan 7, while the air radiator 5 is disposed of the on the other side, that is to say along the other face of the fan 7 for optimal use of the air flow produced by the fan 7.

Thanks to such a design of the powertrain, the charge air whose temperature is close to 170 ° C. at the outlet of the compressor 4 can be cooled to a temperature close to 50 ° C. at the outlet of the air radiator 5 before entry. in engine 2.

Claims (9)

1. Power unit (1) comprising a heat engine (2), a circuit 5 (3) for supplying air to said engine (2), a circuit (16) for engine coolant (2) and a fan (7), said circuit (3) for supplying air to the engine (2 ) comprising a compressor (4) and a radiator (5), said air radiator (5) inside which the air compressed by the compressor (4) is able to circulate to be cooled therein being disposed between the compressor (4) and the engine air intake (6) inlet (6) and near the fan (7) to be arranged at least partially in the air flow produced by the fan (7), characterized in that at least a portion of the circuit (16) of the engine coolant (2) forms, with at least a portion of the portion 15 (31) of the air supply circuit (3) of the engine (2) disposed between the compressor (4) and the air radiator (5), an air / liquid heat exchanger (20). 2. Power unit (1) according to claim 1, 20 characterized in that the part of the portion (31) of the circuit (3) for supplying air to the engine (2) disposed between the compressor (4) and the air radiator (5) and forming an exchanger (20) thermal air / liquid with a portion of the coolant circuit (16), is formed by a plurality of braced, parallel tubes (8) inside which the air from the compressor (4) is 25 capable of circulating from one (9) of the ends, called the air intake, in the direction of the other end (10), called the air exhaust, of each tube (8), said tubes (8) and their spacers (11) being housed inside a tubular envelope (12) delimiting with the spacers (11), disposed axially offset along the tubes (8), an enclosure (13) provided 30 of an inlet (14) and an outlet (15) for circulating fluid arranged on the coolant circuit (16) for supplying coolant to said enclosure (13). 3. Group (1) powertrain according to the preceding claim, characterized in that each spacer (11) takes the form of a plate provided with through holes each housing in an airtight manner the end of a tube ( 8), in that the tubular casing (12) takes the form of an elongated hollow body and in that the tube (8) / spacers (11) assembly is immobilized axially inside said casing (12 ) by coupling airtight spacers (11), preferably at the outer peripheral edge of the spacers (11), to the inner face of the body of the tubular casing (12). 4. Power unit (1) according to one of claims 2 or 3, characterized in that the tubular casing (12) which is an elongated hollow body is provided externally with fins (17). 5. Group (1) powertrain according to the preceding claim, characterized in that the fins (17) affect the shape of parallel circular external radial turns or flanges extending over at least part of the periphery of the envelope (12). 6. Power unit (1) according to one of claims 2 to 5, characterized in that the inlet (14) and the outlet (15) for circulation of fluid from the enclosure (13) delimited by the envelope ( 12) and the spacers (11) are respectively provided one (14), at the ends (10) of air exhaust from the tubes (8), the other (15), at the ends (9 ) air intake of the tubes (8), to allow, inside said enclosure (13), a circulation of the coolant and the air against the current. 7. Group (1) powertrain according to one of claims 2 to 6, characterized in that said enclosure (13) is positioned at the periphery of the fan (7). 8. Group (1) powertrain according to one of claims 2 to 7, characterized in that it comprises a thermostat or a sensor (18) for measuring a parameter representative of the air temperature of the circuit (3 ) air supply to the engine (2) and in that the portion of the circuit (16) of 5 coolant disposed between the engine (2) and the fluid circulation inlet of the enclosure delimited by the casing (12) and the spacers (11) is provided with a controllable shutter member (19) mounted movable between a closed position and an open position depending on the measured temperature data. 9. Self-propelled rolling vehicle characterized in that it is equipped with a powertrain according to one of claims 1 to 8. 1/5