FR3059057A1 - CENTRIFUGAL FAN INTEGRATING THERMAL EXCHANGE CIRCUIT - Google Patents

Abstract

The centrifugal vehicle fan comprises: - at least one inlet orifice, - at least one outlet orifice, and - blades having at least one internal channel communicating with the inlet and outlet ports so that the fan forms at least one fluid circuit extending from the inlet port, through the channels of a plurality of blades and to the outlet port.

Description

® FRENCH REPUBLIC

NATIONAL INSTITUTE OF INDUSTRIAL PROPERTY © Publication number:

(to be used only for reproduction orders) (© National registration number

059 057

59389

COURBEVOIE © Int Cl ⁸ : F04 D 29/58 (2017.01)

PATENT INVENTION APPLICATION

A1

©) Date of filing: 09.29.16. © Applicant (s): VALEO THERMAL SYSTEMS (© Priority: Simplified joint stock company - FR. @ Inventor (s): BLANDIN JEREMY, AZZOUZ KAMEL, BAKIR FARID and KHELLADI SOFIANE. (43) Date of public availability of the request: 25.05.18 Bulletin 18/21. ©) List of documents cited in the report preliminary research: Refer to end of present booklet (© References to other national documents ® Holder (s): VALEO THERMAL SYSTEMS related: Joint stock company. ©) Extension request (s): © Agent (s): VALEO THERMAL SYSTEMS.

CENTRIFUGAL FAN WITH INTEGRATED THERMAL EXCHANGE CIRCUIT.

(£ /) The centrifugal vehicle fan includes:

- at least one inlet,

- at least one outlet, and

- blades having at least one internal channel communicating with the inlet and outlet orifices so that the fan forms at least one fluid circuit extending from the inlet orifice, through the channels of several of the blades and up to the outlet.

FR 3 059 057 - A1

-1 Centrifugal fan incorporating a heat exchange circuit

The present invention relates to motor-driven fan units fitted to a vehicle, more particularly to centrifugal fans.

Motor vehicles include equipment that must be cooled as a result of their temperature rise during operation. This is the case, for example, of a battery electrically supplying the vehicle or of an engine group. To achieve this cooling, the vehicle is equipped with several heat exchangers, for example radiators, inside which a heat transfer fluid circulates. This fluid stores calories released by the equipment to be cooled by passing through this equipment and is cooled as it passes through the heat exchanger. This cooling is effected by an indirect heat exchange, mainly by convection, between the internal heat transfer fluid and an external heat transfer fluid which is the ambient air located around the heat exchanger. The cooled fluid then returns to the organ to be cooled. Other heat exchangers (evaporator, condenser, heating radiator) allow the air conditioning of the passenger compartment to provide thermal comfort to users.

To ensure good performance on the part of these heat exchangers, it is necessary to have a high mass flow rate, in particular as regards the external heat transfer fluid. Commonly, the radiator is ventilated so that fresh air circulates around it, thereby increasing the heat exchange between the radiator and the ambient air. This ventilation is ensured by motor-fan groups (or air exchangers) which can be a propeller combined with a motor for rotating the propeller (called "Fan System") or a centrifugal fan (or " blower >>). The Fan System is commonly used on the front of the vehicle in combination with a radiator or a condenser for example. The centrifugal fan is present in an HVAC box (for "Heating, Ventilation and Air-Conditioning") in combination with a heating radiator or an evaporator for example. These devices are intended to create or amplify a circulation of fresh air around the heat exchangers.

Such cooling devices comprising one or more heat exchangers in combination with one or more motor-driven fan groups have drawbacks in terms of space and mass. In other words, they are relatively bulky and heavy in an environment where space saving

-2and mass is essential in order to be able to set up a relatively light system with an optimal architecture. This gain should not however be achieved at the expense of the level of efficiency and the quality of the various components (for example by reducing the thickness of the walls of the components or by using materials of lower quality).

An object of the invention is to provide a device for cooling a more compact and lighter heat transfer fluid.

To this end, a centrifugal vehicle fan is provided according to the invention, which comprises:

- at least one inlet,

- at least one outlet, and

- blades having at least one internal channel communicating with the inlet and outlet orifices so that the fan forms at least one fluid circuit extending from the inlet orifice, through the channels of several of the blades and up to the outlet.

Thus, the ventilation and heat exchange functions are fulfilled by a single device, which saves space and saves substantial mass. Indeed, the heat exchange function is ensured by the circulation of a heat transfer fluid in the blades, the heat of the fluid being transmitted to the blades and then to the ambient air in which the blades move. The ventilation function, moreover, is ensured by the rotation of the fan. And this rotation itself improves the heat exchange of the first function.

Advantageously, the channels have a section of shape identical to a shape of a section of the blades. Thus, the shape of the channels follows the shape of the blades, which allows an optimal and uniform heat exchange over the entire surface of the blade.

Advantageously, the blades are connected to each other by at least one external crown comprising hollow portions communicating with the channels of the blades, the blades and the crown forming the fluid circuit (s).

Advantageously, the inlet port is connected to a first fan channel and the outlet port is connected to a second fan channel, channels formed in a transverse branch connecting a central hub of the fan and the crown.

-3external.

Advantageously, the inlet and outlet orifices are connected to a rotary connector able to convey a fluid to the circuit.

Advantageously, the number of fluid circuits is at least equal to two. It is thus possible to configure shorter circuits than if the circuit is unique.

Advantageously, at least one of the blades comprises at least one baffle in its hollow part. Thus, the baffle creates turbulence in the heat transfer fluid, which has the effect of increasing the efficiency of the heat exchange.

According to the invention, a cooling system for vehicle equipment is also provided, comprising at least one centrifugal fan as described above.

Advantageously, the fan is in the circuit in addition to at least one radiator.

Advantageously, the fan is arranged in the circuit so as to receive a fluid leaving the radiator.

Alternatively, the centrifugal fan is the only cooling device in the system. Thus, a more compact cooling system is obtained.

A vehicle is also provided according to the invention comprising a cooling system as described above.

In recent years, more and more vehicles powered by a fuel cell have been developed. Such vehicles have different cooling needs from vehicles comprising a heat engine. In fact, the operating temperature of fuel cells is lower than that of a heat engine. The temperature difference between the internal heat transfer fluid and the external heat transfer fluid is therefore smaller at the heat exchanger and the heat exchange is then more difficult to achieve. In addition, the thermal power to be evacuated in this type of vehicle is greater than in the context of a thermal engine. It is then necessary to add an additional propeller to the device

-4 cooling to ensure sufficient air circulation for the cooling of the internal heat transfer fluid and the evacuation of the above thermal powers. This addition is problematic because it leads to an increase in the volume and the mass of the cooling device.

To this end, provision can be made for the centrifugal fan according to the invention to be in a cooling circuit of a fuel cell. Thus, it is possible to produce a more compact and lighter cooling system due to the dual function of the centrifugal fan according to the invention, such a device having no loss in terms of heat exchange efficiency. The centrifugal fan also represents additional thermal cooling power.

Advantageously, the centrifugal fan is in a cooling circuit of an electric motor.

Advantageously, the centrifugal fan is located in a cooling circuit of a power control member.

Advantageously, the vehicle comprises a radiator, the radiator and the centrifugal fan being arranged to be crossed by two separate air flows. Thus, the efficiency of the heat exchange of the two devices through which two different fresh air flows is increased.

Advantageously, the radiator is crossed by air sent by a propeller.

Advantageously, the centrifugal fan is located in a wheel arch. Thus, such a remote fan makes it possible to avoid space congestion and thus to simplify the architecture of the system.

Advantageously, the radiator is located on the front face of the vehicle. Thus, the radiator easily receives fresh air when the vehicle is running.

Advantageously, the vehicle is able to be propelled by means of a fuel cell.

We will now describe an embodiment of the invention on the basis of the appended drawings in which:

FIGS. 1 and 2 are perspective views of a centrifugal fan according to an embodiment of the invention;

- Figure 3 is a perspective view of the centrifugal fan of Figures 1 and 2 without one of its outer rings and showing an enlarged portion of one end of a blade forming a heat exchange channel;

- Figures 4 and 5 are perspective views of a fluid flow circuit inside the fan of Figure 1;

- Figure 6 is a perspective view of the centrifugal fan of Figure 1 with a rotary connector;

- Figure 7 is an exploded view of the centrifugal fan and the connector of Figure 6;

- Figure 8 is a perspective view of the fluid flow circuit of Figures 4 and 5 showing a first direction of flow;

- Figure 9 is a perspective view of the fluid flow circuit of Figures 4 and 5 showing a second direction of flow;

- Figure 10 is a perspective view of a fluid flow circuit inside the centrifugal fan according to a second embodiment of the invention;

- Figure 11 is a schematic representation of a cooling circuit comprising a centrifugal fan according to the invention in addition to a radiator within a cooling loop; and

- Figure 12 is a schematic representation of a cooling circuit comprising two centrifugal fans according to the invention as the only cooling members of a cooling loop.

FIGS. 1 to 7 illustrate a centrifugal fan 2 according to an embodiment of the invention.

By centrifugal fan is meant a fan composed of an impeller or blades, driven in rotation by a motor. The impeller receives ambient air and creates or amplifies an air flow from the received ambient air.

This fan 2 comprises a central hub 4 parallel to a main axis A of the fan 2. This hub is able to collaborate with a drive mechanism (not shown). Several straight branches 6 extend from the central hub 4 to the outside. Each of the branches 6 is connected at its proximal end to the central hub and at its distal end to an external flat circular crown 8 situated in a plane perpendicular to the main axis A. The assembly formed by the branches 6 and the external crown 8 is rigid and possibly designed in one piece.

The centrifugal fan 2 also includes several blades 10 distributed regularly along the outer ring 8 and perpendicular to the latter. Consequently, the blades extend parallel to the main axis A of the centrifugal fan 2. The blades 10 are connected at one of their ends to the crown 8 and at the other end to an external crown 12 parallel to the crown 8 and similar to the latter. The set of blades 10, outer rings 8 and 12, branches 6 and the central hub 4 form the impeller of the centrifugal fan 2.

All the blades 10 are hollow, as illustrated in FIG. 3. The external face of each blade is curved and has a pressure side and a suction side in cross section. It increases the contact surface between the ambient air and the external face of the blade and therefore the heat exchange between the two.

Each blade is hollow and has an internal channel occupying most of the blade. The channel 14 formed inside each blade has a section of identical shape and homothetic to the shape of the section of the external face of the blade in order to increase the contact surface between a heat transfer fluid, generally a liquid, circulating in the centrifugal fan 2 and each of the blades 10. Thus, this shape identity combined with the advantageous shape of each blade 10 makes it possible to optimize the heat exchange between the heat transfer fluid circulating in the fan 2 and the ambient air via the blades 10. The heat transfer fluid circulating in the centrifugal fan can be a liquid, a gas or a liquid / gas mixture.

According to another possible embodiment (not illustrated), the channel is formed inside only one or more blades, preferably having a section of identical shape and homothetic to the shape of the section of the external face of the blade for the above advantages.

In a first embodiment of the invention illustrated in FIGS. 8 and 9, the centrifugal fan 2 has a fluid inlet orifice 16 and a fluid outlet orifice 18. Each of the rings 8 and 12 comprises hollow portions of so as to create a fluid circuit as illustrated in FIGS. 4 and 5. The blade 10a is thus connected to the next blade 10b by a hollow portion 12a produced in the outer ring 12. The blade 10b is in turn connected to the next blade 10c by means of a hollow portion 8a produced in the outer ring 8. This alternation is then repeated in order to connect all of the blades 10 by means of the two

-7 crowns 8 and 12. When two blades are connected by a hollow portion of a crown, the other crown opposite this hollow portion does not include a wall but simply two curved lateral rods 13 and 15. The fluid circuit thus constituted, visible in particular in FIGS. 4 and 5, therefore has a configuration in boustrophedon and in slots.

In order to convey the fluid in the blade / crown circuit thus formed, two additional channels are arranged in one of the transverse branches 6. The channel 20 connects the inlet orifice 16 to the crown 8 and the channel 22 connects this same crown 8 at the outlet. In order to define a direction of circulation, the hollow portion of the crown 8 connected to the channels 20 and 22 is divided into two parts 8b and 8c. Part 8b communicates exclusively with the inlet port 16 through channel 20 and part 8c communicates exclusively with the outlet port 18 through channel 22.

In order to make the fluid flow circuit completely sealed, closing elements 24 and 26 are mounted respectively on the crowns 8 and 12. More specifically, these elements constitute the fourth wall of the hollow portions of the outer crowns 8 and 12 and channels 20 and 22.

In order to convey the heat transfer fluid from the outside of the centrifugal fan 2 to the fluid flow circuit of the fan, a rotary connector 28 is connected to the centrifugal fan 2. This connector makes it possible to connect a mobile part of the cooling circuit (here the centrifugal fan 2 mobile in rotation) to the fixed part of the cooling circuit. The rotary connector 28, known in itself, comprises two orifices 30 and 32 allowing the connection between the fluid circuit external to the fan and the orifices 16 and 18.

In a second embodiment of the invention illustrated in FIG. 10, the fan 102 comprises two inlet ports 116a and 116b and two outlet ports 118a and 118b. Port 116a is connected to a channel 120a, port 116b is connected to a channel 120b, port 118a is connected to a channel 122a and port 118b is connected to a channel 122b. Channels 120a and 120b are respectively linked to parts 138 and 140 of the outer ring 8, parts which are distinct from each other like parts 8b and 8c. The channels 122a and 122b are connected in turn to the part 142 of the outer ring 8. The circuit formed by the set of blades 10 in combination with the hollow portions of the outer rings 8 and 12 is in turn identical to that of Figures 4, 5, 8 and 9.

In this embodiment, two fluid circuits are formed in the centrifugal fan 102 according to a parallel assembly. Each circuit again has a boustrophedon and slot configuration.

In operation, the heat transfer fluid can circulate in the circuit of the centrifugal fan 2 in several directions, as illustrated in FIGS. 8 to 10. The circuit of FIGS. 8 and 9 is identical to that of FIGS. 4 and 5.

In FIG. 8, the fluid enters through the orifice 16 and then crosses the channel 20 in order to arrive in the part 8b of the crown 8. It then circulates in the entirety of the blades passing alternately through the external crown 8 and the external crown 12. Finally, the fluid arrives at the part 8c then passes through the channel 22 and leaves the centrifugal fan 2 through the orifice 18. This circulation defines a direction of circulation represented by the arrow 34.

In FIG. 9, the direction of circulation of the fluid is reversed. The fluid enters through the orifice 18 then crosses the channel 22 in order to arrive in the part 8c of the crown 8. It then circulates in the entirety of the blades passing alternately through the outer crown 8 or the outer crown 12. Finally , the fluid arrives at part 8b then passes through the channel 20 and leaves the centrifugal fan 2 through the orifice 16. This circulation defines a direction of circulation represented by the arrow 36.

In Figure 10, two fluid circuits are present. In the first circuit, the fluid enters through the orifice 116a then crosses the channel 120a in order to arrive in the part 138 of the crown 8. It then circulates in half of the blades 10 of the fan 2 passing alternately through the external crown 8 and the outer ring 12. Finally, the fluid arrives at the part 142 then passes through the channel 122a and leaves the centrifugal fan 2 through the orifice 118a. This circulation defines a direction of circulation represented by the arrow 144. Simultaneously, in the second circuit, the fluid enters through the orifice 116b then crosses the channel 120b in order to arrive in the part 140 of the crown 8. It then circulates in the other half of the blades 10 of the fan passing alternately through the outer ring 8 and the outer ring 12. Finally, the fluid arrives at the part 142 then passes through the channel 122b and leaves the centrifugal fan 2 through the orifice 118b. This circulation defines a direction of circulation represented by the arrow 146.

At least one centrifugal fan 2 such as those just described can

-9be placed in a cooling circuit like that of the embodiments illustrated in Figures 11 and 12.

In FIG. 11, the centrifugal fan 2 is inserted into the cooling circuit 70 of a fuel cell 48 in addition to another heat exchanger, here a radiator 50, in a first loop or cooling circuit. More particularly, it is a so-called high temperature radiator, that is to say ensuring the cooling of a member operating between 80 and 100 ° C. Preferably, the radiator 50 and the fan 2 are crossed by two separate air flows. The fan 2 can for this purpose be offset, for example in a wheel arch (here the left wheel 58), which will also make it possible to free up space at the cooling circuit. The radiator 50 is generally positioned on the front face of the vehicle in order to receive fresh air during driving. In a second cooling loop or circuit, a so-called low temperature radiator 60 (cooling organs operating at a temperature between 40 and 60 ° C), also arranged on the front face, for example upstream of the fan 50, this is that is to say in front, provides only the cooling of an electric motor 62 and of a power control member 64. The two fans receive a flow of air generated or amplified by a propeller 66. The centrifugal fan 2 provides only its ventilation. The two loops are separate, separate and independent with regard to the heat transfer fluid that they circulate.

In operation, the radiator 50 receives the liquid leaving the fuel cell 48, as illustrated by the arrow 52, cools it, in particular by means of the fan 66, then, taking into account the large thermal powers to be evacuated, the liquid leaving the radiator 50 is sent to fan 2 as illustrated by arrow 54, to be further cooled there. Finally, the liquid leaving the fan 2 returns to the fuel cell 48, as illustrated by the arrow 56, to heat up.

Similarly, the radiator 60 receives the hot liquid leaving the member 64 and the motor 62, cools it with the help of the fan 66 and returns it to these two devices.

In the cooling circuit 72 of the embodiment illustrated in FIG. 12, two centrifugal fans 2 are inserted in the cooling circuit of the electric motor 62 and of the power control member 64. They are the only cooling members of this cooling loop. Advantageously, the two centrifugal fans 2 are housed respectively in the front left 58 and front right 68 wheel arches.

In another cooling loop, the high temperature radiator 50 alone cools the fuel cell 48. This fan, disposed on the front face of the vehicle, receives a flow of air generated or amplified by the propeller 66. In the event removal of the low temperature radiator, as is the case here, space is freed up on the front of the vehicle, which makes it possible to increase the size of the high temperature radiator 50 and consequently the heat exchange surface of this last. There is then better cooling of the fluid passing through the high temperature radiator 50.

In operation, each of the two centrifugal fans 2 simultaneously cools the electric motor 62 and the power control member 64. Downstream of the motor 62, the liquid circuit is divided into two branches directing flows of liquid towards the respective fans 2, these two streams, once cooled, meet to penetrate the member 64.

The invention is not limited to the embodiments presented and other embodiments will be apparent to those skilled in the art. It is in particular possible to make more than two fluid circuits in the centrifugal fan. In addition, it is possible that the centrifugal fan is associated with a low temperature radiator in a cooling loop.

Claims (20)

1. Vehicle centrifugal fan (2; 102), characterized in that it comprises: - at least one inlet (16; 116a; 116b), - at least one outlet (18; 118a; 118b), and - blades (10) having at least one internal channel (14) communicating with the inlet and outlet orifices so that the fan forms at least one fluid circuit extending from the inlet orifice, through the channels of several of the blades and up to the outlet. 2. Fan (2; 102) according to claim 1, wherein the channels (14) have a section of shape identical to a shape of a section of the blades. 3. Centrifugal fan (2; 102) according to any one of the preceding claims, in which the blades (10) are interconnected by at least one outer ring (8, 12) comprising hollow portions communicating with the channels (14 ) blades, the blades and the crown forming the fluid circuit (s). 4. Centrifugal fan (2; 102) according to the preceding claim, wherein the inlet port (16; 116a; 116b) is connected to a first channel (20; 120a; 120b) of the fan and the outlet port (18; 118a; 118b) is connected to a second fan channel (22; 122a; 122b), channels formed in a transverse branch (6) connecting a central hub (4) of the fan and the outer ring (8). 5. Centrifugal fan (2; 102) according to any one of the preceding claims, in which the inlet (16; 116a; 116b) and outlet (18; 188a; 118b) orifices are connected to a rotary connector (28 ) suitable for conveying a fluid to the circuit. 6. Fan (2; 102) according to any one of the preceding claims, wherein the number of fluid circuits is at least two. 7. Fan (2; 102) according to any one of the preceding claims, in which at least one of the blades (10) comprises at least one baffle in its hollow part. 8. Cooling system (70; 72) of vehicle equipment comprising at least one centrifugal fan (2; 102) according to any one of the preceding claims. 9. Cooling system (70) according to claim 8, wherein the fan (2; 102) is located in the circuit in addition to at least one radiator (50). 10. Cooling system (70) according to 9, in which the fan (2; 102) is arranged in the circuit so as to receive a fluid leaving the radiator (50). 11. Cooling system (72) according to claim 8, in which the centrifugal fan (2; 102) is the only cooling member of the system. 12. Vehicle comprising a cooling system (70; 72) according to any one of claims 8 to 11. 13. Vehicle according to claim 12, wherein the centrifugal fan (2; 102) is located in a cooling circuit of a fuel cell (48). 14. Vehicle according to any one of claims 12 and 13, wherein the centrifugal fan (2; 102) is located in a cooling circuit of an electric motor (62). 15. Vehicle according to any one of claims 12 to 14, wherein the centrifugal fan (2; 102) is located in a cooling circuit of a power control member (64). 16. Vehicle according to claim 12 to 15 comprising at least one radiator (50; 60), the radiator and the centrifugal fan being arranged to be traversed by two separate air flows. 17. Vehicle according to claim 16, in which the radiator (50; 60) is traversed by air sent by a propeller (66). 18. Vehicle according to any one of claims 12 to 17, wherein the centrifugal fan (2; 102) is located in a wheel arch (58; 68). 19. Vehicle according to any one of claims 16 to 18, wherein the radiator (50; 60) is located on the front face of the vehicle. 20. Vehicle according to any one of claims 12 and 19, the vehicle being adapted to be propelled by means of a fuel cell (48). 1/5 2/5 8b δ 3x _s 2δ 4/5 116a 12a 140 - 8b / 8a 10c