WO2002079621A1

WO2002079621A1 - Device, system and method for cooling a coolant

Info

Publication number: WO2002079621A1
Application number: PCT/FR2002/000021
Authority: WO
Inventors: Nicolas Vidal; Robert Yu
Original assignee: Renault S.A.S
Priority date: 2001-01-05
Filing date: 2002-01-04
Publication date: 2002-10-10
Also published as: EP1362168B1; DE60216049T2; EP1362168A1; DE60216049D1

Abstract

The invention concerns a device for cooling (6) a coolant by heat exchange with another fluid, comprising an intake (27), an outlet (6a) for the coolant, and an auxiliary outlet (6b) so that the coolant coming out of the auxiliary outlet (6b) is at a lower temperature than the fluid coming out of the main outlet (6a).

Description

Device, system and method for cooling a heat transfer fluid.

The present invention relates to a cooling system for a hybrid propulsion vehicle.

Hybrid powered vehicles generally include a heat engine, one or two electric motors, an electric voltage generator, and an electronic power converter assembly which either powers the electric motor (s) or charges the batteries, all of which need to be cooled. in order to operate under the conditions for which they are intended. We are trying to take advantage of this dual engine to reduce consumption and polluting emissions as much as possible, so as to stay below authorized levels.

It has been found that the ranges of flow rate and temperature of the coolant are very different for an electric motor and for a heat engine. The coolant of an electric motor has a flow rate of the order of 100 to 500 l / hour at a temperature of 50 to 70 °. The coolant of a heat engine has a flow which can be twenty times higher, at a temperature of the order of 100 to 110 ° maximum. These differences in flow and temperature make it difficult to use a single circuit and a single radiator operating under optimal conditions in all the situations encountered for a hybrid propulsion vehicle.

Document FR 2 748 428 (RENAULT) describes a cooling system for a hybrid propulsion vehicle comprising a heat engine and an electric motor, comprising a liquid coolant circulating in the engines and in a radiator and means so that, the thermal engine being stopped and the electric motor being running, the coolant circulates in a first part of the radiator only, and so that the two engines being in operation, the heat transfer liquid circulates in the two parts of the radiator.

However, when the two motors are running, the electric motor sees a coolant pass at relatively high temperature. The Japanese abstract 10 266 855 (TOYOTA) describes a cooling system comprising a radiator, an expansion tank common to a circuit dedicated to the heat engine and to a circuit dedicated to the electric motor. The radiator has two inputs and two outputs connected to two water boxes, one of which is divided by a partition. The other water box has no partition and the two circuits are in communication through it. During operation, the water in the two circuits hardly mixes.

However, the heat released by the electric motor cannot be used to heat or preheat either the heat engine or the passenger compartment of the vehicle. The electric motor circuit pump operates as long as the electric motor is in operation, which reduces the service life of said pump. When the electric motor is not in service the radiator which is dedicated to it is useless and does not benefit the cooling of the heat engine and vice versa when the heat engine is not in service the radiator which is dedicated to it is used to nothing and does not benefit the cooling of the electric motor.

The present invention proposes to overcome the limitations of conventional techniques by proposing a device and a cooling system operating optimally in all cases and making it possible to reduce energy consumption and polluting emissions.

The present invention proposes to reduce the operating time of a coolant circulation pump in the electric motor. The present invention proposes to maintain the engine electric at low temperature.

The device for cooling a heat transfer fluid by heat exchange with another fluid, according to one aspect of the invention, comprises an inlet and an outlet for heat transfer fluid. The device includes an auxiliary outlet so that the heat transfer fluid from the auxiliary outlet is at a temperature lower than that of the main outlet.

In one embodiment of the invention, the device comprises a first portion disposed between the main inlet and the outlet and a second portion disposed between the auxiliary inlet and outlet, the two portions being integrated into a radiator body.

In one embodiment of the invention, the main output and the auxiliary output are arranged at opposite ends of the device. In another embodiment of the invention, the main output and the auxiliary output are arranged at the same end of the device.

The device can be provided with a single inlet or with two close inlets, for example connected to the same water box. The path of the heat transfer fluid is longer between the auxiliary inlet and outlet than between the main inlet and outlet. In other words, the residence time in the device of the heat transfer fluid from the auxiliary outlet is greater than that of the heat transfer fluid from the main outlet. The cooling system, according to one aspect of the invention, is intended for a hybrid propulsion vehicle comprising a heat engine and at least one electric motor. The system is of the type comprising a heat transfer fluid capable of cooling the thermal and electric motors, a radiator capable of cooling the heat transfer fluid by heat exchange with a stream of air and comprising a plurality of cooling channels, an inlet and an outlet, a first pipe between the outlet of the radiator and the heat engine and a second pipe between said engine and the inlet of the radiator. The radiator includes an auxiliary outlet so that the heat transfer fluid from the auxiliary outlet is at a temperature lower than that of the main outlet connected to the first pipe, said auxiliary outlet being connected to a bypass pipe capable of cooling the electric motor.

Preferably, the bypass pipe comprises a first branch connected to the auxiliary output and a second branch connected to a pipe upstream of the heat engine.

Preferably, the first branch is able to be connected to the first pipe.

The first branch can pass through the electric motor and an electronic power unit of the electric motor.

The first branch can be equipped with a circulation pump for the heat transfer fluid.

In one embodiment of the invention, the second branch is connected to an outlet pipe of a radiator for heating a passenger compartment of a vehicle.

In one embodiment of the invention, the bypass pipe comprises a third branch connected to the second pipe.

In one embodiment of the invention, the bypass pipe comprises a fourth branch connected to the output of the heat engine upstream of a thermostat.

In one embodiment of the invention, the branches of the bypass pipe are connected together by a multi-way valve. A thermostat can be integrated into said multi-way valve. The multi-way valve may include a rotary control core.

In one embodiment of the invention, said circulation pump for the heat transfer fluid is driven by the electric motor.

In another embodiment of the invention, said heat transfer fluid circulation pump is driven independently of the electric motor.

In a preferred embodiment of the invention, the system comprises a thermostat disposed on the first pipe, the thermostat being able to close the first pipe, a pipe connected to the electric motor being able to be in communication with the heat engine. In one embodiment of the invention, the system comprises a first valve able to put the output of the electric motor into communication at least with the heat engine.

In one embodiment of the invention, the first valve is of the multi-channel type and is capable of putting the output of the electric motor into communication with the heat engine or with the second pipe.

In one embodiment of the invention, the system comprises a second valve able to put the auxiliary output into communication at least with the electric motor.

In one embodiment of the invention, the second valve is of the multi-channel type and is capable of putting the auxiliary output into communication with the electric motor or with the heat engine. In one embodiment of the invention, the electric motor is mounted on a bypass pipe parallel to the heat engine.

In one embodiment of the invention, said auxiliary output is connected to a bypass line capable of cooling an electronic control unit.

The invention also relates to a vehicle comprising a cooling system as above.

The invention also provides a cooling method for a hybrid propulsion vehicle comprising a heat engine and at least one electric motor cooled by the circulation of a heat transfer fluid in said engines, a heat exchange means capable of cooling the heat transfer fluid by heat exchange with another fluid and provided with an inlet and an outlet, process in which the flow of heat transfer fluid is divided in the heat exchange means between a main outlet and an auxiliary outlet so that the heat transfer fluid from the auxiliary outlet has a temperature lower than that of the main outlet, said auxiliary outlet being connected to a bypass pipe capable of cooling the electric motor. Cooling can be carried out in series, the fluid coolant passing through the bypass pipe then passing into the heat engine which is preferable in case of high temperature at the outlet of the heat exchange means.

Advantageously, the flow of heat transfer fluid in the bypass line is varied as a function of the temperature at the outlet of the heat exchange means.

In one embodiment of the invention, if the temperature of the heat transfer fluid is insufficient to cause the opening of a thermostat disposed at the outlet of the heat engine, the heat transfer fluid is circulated in the bypass line connected thirdly to the inlet of the heat exchange means, for cooling the electric motor in the absence of circulation of heat transfer fluid in the heat engine. This operating mode can also be adopted when the engine is stopped.

In one embodiment of the invention, in the event of a temperature of the heat transfer fluid significantly lower than the opening temperature of a thermostat disposed at the outlet of the heat engine, the heat transfer fluid is circulated in the connected bypass pipe of fourth leaves at the outlet of the heat engine upstream of the thermostat, to cool the electric motor while warming up the heat engine. It is thus possible to obtain a faster rise in temperature of the heat engine when it starts and to reduce the formation of polluting elements. This operating mode can also be adopted when the heat engine is stopped, if the pump associated with the heat engine is electrically driven or if said pump can be bypassed. It is thus possible to preheat the heat engine.

The invention will be better understood and other advantages will appear on reading the detailed description of a few embodiments taken by way of non-limiting examples and illustrated by the appended drawings, in which:

- Figure 1 is a schematic view of a cooling system according to an embodiment of the invention; - Figure 2 is a schematic view of a radiator; - Figures 3 to 8 and 10 to 16 are schematic views of a cooling system according to other embodiments of the invention;

- Figure 9 is a schematic view of another radiator; and - Figure 17 is a diagram of a valve.

To simplify our description, the term "electric motor" defines all the machines which convert electrical energy into mechanical energy, or mechanical energy into electrical energy, and the term "power electronics" defines all of the electronics which convert alternating current into direct current, direct current into alternating current, high voltage current into low voltage current, or low voltage current into high voltage current.

As can be seen in FIG. 1, the cooling system is associated with a heat engine 1 and an electric motor 2 provided with an electronic power unit 3. There is also provided a heating radiator 4 making it possible to heat the passenger compartment of the vehicle in which the cooling system is installed, as well as an exchanger 5 making it possible to cool any fluid, for example lubricating oil, gearbox oil, etc. or any organ, for example a turbocharger bearing, ...

The cooling system comprises a radiator 6, a main outlet 6a of which is connected to a pipe 7 and the inlet of which is connected to a pipe 8. The pipe 7 is connected to a pump 9, the outlet of which is connected to the heat engine 1. The pump 9 can be driven by the heat engine 1 or by an electric motor which is dedicated to it and which has not been shown. The outlet of the engine 1 is provided with a thermostat 10, itself connected to the pipe 8. The radiator 6 is generally provided with a motorized fan 11 capable of accelerating the flow of air through said radiator 6.

The cooling system comprises a temperature sensor 12 disposed at the outlet of the engine 1, immediately upstream of the thermostat 10, a temperature sensor 13 mounted on the pipe 7 at the outlet of the radiator 6, and a control unit 14 receiving temperature information from sensors

12 and 13. The link between the control unit 14 and the sensors 12 and

13 can be carried out by dedicated electrical wires or via a communication bus. The input of the heating radiator 4 is connected to an output of the heat engine 1 and the output of the radiator 4 is connected to the pipe 7. Likewise, the input of the exchanger 5 is connected to an output of the heat engine 1 and its output is connected to line 7.

The cooling system further comprises a bypass line referenced 15 as a whole and provided with several branches, and a multi-way valve 16 to which said branches are connected.

More specifically, a first branch 17 is connected, on the one hand to an auxiliary output 6b of the radiator 6 and, on the other hand to the multi-way valve 16. The branch 17 passes through the electric motor 2 and through the unit of power 3. The circulation of the coolant in said branch 17 makes it possible to maintain the electric motor 2 and the power unit 3 at a normal operating temperature, if possible sufficiently low so that common industrial components, both electric and electronic, can be used in the construction of these elements.

There is also an electric pump 21 arranged on the branch 7, controlled by the control unit 14 and circulating the cooling fluid in said branch 17. A second branch 18 is connected at one end to the first pipe 7 to near the pump 9 and at the opposite end to the multi-way valve 16.

A third branch 19 is connected, on the one hand to the pipe 8 and, on the other hand to the multi-way valve 16. A fourth branch 20 is connected, on the one hand to an output of the heat engine 1 upstream of the thermostat 10 and, on the other hand to the multi-way valve 16. The multi-way valve 16 is able to put branches 17 and 18 into communication by closing branches 19 and 20, to put branches 17 and 19 into communication by closing off the other branches and connecting the branches 17 and 20 by closing off the other branches, and this on the order of the control unit 14 to which it is connected.

In other words, the multi-way valve 16, which is here four-way, has the function of ensuring the selective passage of the cooling fluid between the branch 17 and one of the three other branches 18, 19 or 20 .

In addition, the bypass line 15 comprises a fifth branch 22 and a 3-way valve 23. The valve 23 is mounted on the branch 17 near the outlet 6b of the radiator 6, in other words between the outlet 6b and the pump 21. The fifth branch 22 is connected, on the one hand to the valve 23 and, on the other hand to the pipe 7 downstream of the temperature sensor 13.

The structure of the radiator 6 is illustrated in more detail in FIG. 2. The radiator 6 comprises a plurality of parallel pipes and two water boxes 24 and 25 into which the ends of the pipes open. The water box 24 is divided into an upstream part 24a and a downstream part 24b by a partition 26 forming a sealed separation. The upstream part 24a is connected to an input 27 of the radiator 6. The downstream part 24b is connected to the main output 6a.

The water box 25 is divided into an upstream part 25a and a downstream part 25b by a partition 28 forming a watertight separation. The upstream part 25a connects pipes connected to the upstream part 24a and pipes connected to the downstream part 24b. The radiator 6 is said to have a U-shaped circulation, the upstream part 25a forming the bottom of the U. The downstream part 25b is connected to the auxiliary output 6b. The downstream part 24b connects pipes connected to the upstream part 25a and pipes connected to the downstream part 25b.

The cooling fluid performs, by passing through the radiator 6, a first pass from the upstream part 24a of the water box 24 to the upstream part 25a of the water box 25, then a second pass from the upstream part 25a of the box 25 to the downstream part 24b of the water box 24 and is divided into two flows, one passing through the main outlet 6a, the other making a third pass from the downstream part 24b of the water box 24 to the downstream part 25b of the water box 25. Said other flow takes advantage of a longer heat exchange and leaves the radiator 6 at a temperature lower than that of the flow passing through the main exit 6a. In some cases one of the flows may be zero. It is therefore possible to maintain the electric motor 2 and the power unit 3 at a low temperature allowing the use of large-scale industrial components at low cost. The operation of the cooling system is as follows.

1) Heat engine 1 running.

If the water temperature as measured by the sensor 12 is less than a predetermined temperature T _ςl and which is less than or equal to the opening temperature T _ot of the thermostat 10, generally between 83 and 89 ° C, the multi-way valve 16 connects the branches 17 and 20 and allows the fluid to pass from the branch 20 to the branch 17. The pump 21 is stopped. The cooling fluid which is in the heat engine 1 is subjected to a high pressure due to the pump 9, pressure higher than that prevailing in the branch 17. The valve 23 puts the branches 17 and 22 in communication and allows to leave pass the fluid from branch 17 to branch 22. The valve 23 cuts the outlet 6b. In this state, which is that of an operation at the start of the heat engine 1 or at very low load, no energy is consumed by the pump 21 which is stopped. The heat released by the operation of the electric motor 2 and of the power unit 3 makes it possible to increase the temperature of the heat engine 1 and therefore to reduce the duration of its rise in temperature, which results in the reduction of the quantity of polluting elements generated by the combustion of the heat engine 1. Keeping the pump 21 at a standstill reduces its operating time and therefore allows a longer overall service life. If the sensor 12 indicates a water temperature greater than or equal to the temperature T _cl but lower than the temperature T _ot opening the thermostat 10, the multi-way valve 16 puts branches 17 and 19 into communication. The pump 21 is started at low speed, for example with a low supply voltage U _j . The valve 16 is maintained as before or on the contrary cuts branch 22 and opens outlet 6b. The electric motor 2 and its power unit 3 are then cooled by means of the radiator 6, the heat exchange capacity of which is much greater, for example by a factor of the order of 3 to 5, than the heat capable of be released by the electric motor 2 and its power unit 3. The pipe 8, the radiator 6 and the pipe 7 being dimensioned for the high flow rates of coolant required by the heat engine 1, the pressure drops are low. The energy consumed by the pump 21 is therefore also low. Its wear is also. If the sensor 12 indicates a water temperature greater than or equal to the temperature T _ot , the multi-way valve 16 communicates the branches 17 and 18. The pump 21 is started. The valve 23 cuts the branch 22 and opens the outlet 6b.

In other words, the flow rate of the output 6b of the radiator 6 passes through the branches 17 and 18. The electric motor 2 and its power unit 3 are cooled by coolant at low temperature.

In addition, it can be provided that if the temperature sensor 13 at the outlet of the radiator 6 indicates a coolant temperature below a predetermined temperature T _c2 , the pump 21 operates at low flow rate, for example with the low voltage of supply U _j , and on the other hand if the sensor 13 indicates a temperature greater than the temperature T _c2 , the pump 21 operates at high flow rate, for example supplied by a voltage U ₂ greater than U _j to obtain a higher flow rate in the branch 17. It will be understood that

T _c2 is greater than T _ot .

Of course, the control unit 14 of the cooling system can control the operation of the fan 11 as a function of the temperature measured by the sensor 13. 2) Thermal engine 1 stopped, vehicle fully electric.

If the water temperature measured by the sensor 12 is lower than the temperature T _cl , the multi-way valve 16 puts branches 17 and 20 into communication and allows the fluid to pass from branch 17 to branch 20 The valve 23 connects the branches 17 and 22 and allows the passage of the fluid from branch 22 to branch 17. The valve 23 cuts the outlet 6b. The pump 21 is started at low flow rate, for example supplied by the voltage U _j . It is thus possible to heat the heat engine 1 and, if necessary, the passenger compartment by the radiator 4. If the water temperature measured by the sensor 12, is higher than the temperature T _cl , the multi-way valve 16 switches on communication branches 17 and 19 and allows the fluid to pass from branch 17 to branch 19. The valve 23 cuts the branch 22 and opens the outlet 6b. The pump 21 is started at low flow rate, for example supplied by the voltage U _j . This mode allows excellent cooling of the electric motor 2 and the power unit 3 because the coolant passes through all of the radiator 6 (three passes).

An intermediate cooling performance can also be obtained by passing the water only through the third pass of the radiator 6 using the multi-way valve 16 which connects the branches 17 and 18. This intermediate configuration can be advantageous for reduce the possible oscillation of the water temperature during the transition from the temperature rise and heating phase to the super cooling phase described above.

If the sensor 13 indicates a temperature higher than the temperature T _c2 , the fan 11 is started up, however, this will rarely happen, hence a reduction in the operating time of said fan 11 and a reduction in consumption. energy.

3) Electric motor 2 stopped, without the need to cool electronic components.

The pump 21 can be started to pass cooling fluid into the third pass and thus provide additional cooling of the heat engine. The valve 16 puts the branches 17 and 18 into communication. The valve 23 puts the branch 17 into communication with the outlet 6 b and closes the branch 22. As a variant, provision may be made to keep the pump 21 at stopping and connecting the branch 22 with the outlet 6b and while closing the branch 17 by means of the valve 16.

Thus, the water temperature at the inlet of the electric motor 2 and of the electronic power unit 3 remains very low in all operating cases. For cases where the temperature measured by the sensor 13 is greater than T _c2 , an increase in the flow rate of the pump 21 and / or the triggering of the fan 11 makes it possible to maintain this temperature within the desired limits.

Thanks to the invention, the pump 21 needs a low power, runs slower and less frequently. In an operating case, the pump 21 is stopped. In two other operating cases where the thermostat is closed, the heat exchange capacity of the radiator 6, dimensioned for the heat losses of the heat engine 1, is largely in excess of the heat losses of the electric motor 2 and of the electronic unit. of power 3 and therefore allows the pump 21 to operate at low flow rate. Finally, the branches 17, 18 and 19 are connected to pipes 7 and 8 of large diameter, which minimizes the pressure drop undergone by the fluid entrained by the pump 21. It was assumed above that the pump 21 was driven by an independent electric motor. It is also conceivable that the pump 21 is driven by the electric traction motor 2. This is advantageous for the cost and the service life of the system. Indeed, a conventional electric pump is generally direct current. Compared to a mechanical pump, the electric motor is the main additional cost of an electric pump and generally has a significantly shorter service life than that of the mechanical pump. The operation of the system is then as follows.

If the water temperature measured by the sensor 12 is lower than the temperature T _ot the thermostat opening, the branches

17 and 19 are connected. If the water temperature measured by the sensor 12 is greater than or equal to the temperature T _ot , and if the vehicle is in electric traction mode, heat engine 1 stopped, the fluid communication between the branches 17 is maintained and 19. If the coolant temperature measured by the sensor 12 becomes greater than or equal to the temperature T _ot , and if the heat engine is in operation, the valve 16 puts branches 17 and 18 into communication. In addition, if the sensor 13 measures a temperature greater than the predetermined temperature T _c2 , the fan 11 is put into action, especially if the vehicle speed is low, for example less than a value between 60 and 80 km / h.

In FIG. 3, a variant is illustrated in which the electric motor 2 and the electronic power unit 3 are cooled in parallel, the branch 17 dividing into a sub-branch

17a passing through the electric motor 2 and into a sub-branch 17b passing through the electronic power unit 3.

In FIG. 4, a variant is illustrated in which the valve 23 and the branch 22 are eliminated. The branch 17 is permanently in communication with the output 6b. This economic variant is advantageous if the heating of the heat engine 1 is not a priority.

In FIG. 5, a variant close to the previous one is illustrated except that the branch 20 is deleted. The valve 16 is three-way. This economic variant is advantageous if the heating of the heat engine 1 is not a priority and if the life of the pump 21 is not critical, for example if the pump 21 is driven by the electric motor 2.

In FIG. 6, a variant close to that of FIG. 1 is illustrated. The radiator 6 is of the two pass type with a water box 24 devoid of a partition. The cooling fluid passes between the inlet 27 and the outlet 6a.

In FIG. 7, a variant close to that of FIG. 5 is illustrated except that the branch 19 and the valve 16 are eliminated. When the thermostat 10 is closed with the pump 21 running and for certain speeds of the heat engine 1, the cooling fluid coming from the radiator 4 and from the exchanger 5 can enter via the outlet 6a of the radiator 6, make a pass, and exit by exit 6b. The cooling fluid coming from the branch 18 can pass through the pump 9 and the heat engine 1. In FIG. 8, a variant close to that of FIG. 7 is illustrated except that the branch 18 is connected to the pipe 7 closer to the outlet 6a, in other words between the sensor 13 and the branch towards the exchanger 5. In FIG. 9 is illustrated a variant of a radiator close to that of FIG. 2, except that the water box 24 is divided into three parts upstream 24a, central 24b, and downstream 24c by partitions 26 and 29. The downstream part 24c is connected to the auxiliary output 6b. The downstream part 25b of the water box 25 connects the pipes connected to the central part 24b and the pipes connected to the downstream part

24c. The radiator 6 is said to have four passes with circulation in double U. An even lower temperature at the auxiliary output 6b is obtained.

The main output 6a can be provided for current operation at around 90 to 105 ° C, desired temperature for the heat engine, without risk of overconsumption of fuel linked to too low a temperature. The auxiliary output 6b can provide for current operation at a significantly lower temperature, allowing good efficiency of the electric motor and the electronic power unit and their construction from inexpensive standard components.

In FIG. 10, another embodiment is illustrated in which the thermostat 10 is arranged on the pipe 7 upstream of the pump 9, itself mounted immediately upstream of the motor 1. The bypass pipe 15 comprises a branch 17 passing through the electric motor 2, the control unit 3 and the electric pump 21. A temperature sensor 30 is mounted between the electric pump 21 and the control unit 3. Upstream of the electric pump 21, the branch 17 is connected to a three-way valve 23 also connected to the outlet 6b of the radiator 6 and to a pipe 31. The pipe 31 joins the branch 18 coming from the three-way valve 16. The branch 18 opens into a pipe 32 which passes through the heating radiator 4 which is connected at one end to the pipe 8 and at another end to a downstream part of the thermostat 10. A temperature sensor 12 is associated with the thermostat 10. The thermostat 10 is suitable closing the pipe 7, while the pipe 32 is in free communication with the pump 9 and the motor 1.

The pump 21 and the valves 16 and 23 are controlled by the control unit which has not been shown in the figure. The three-way valve 16 connects the branch 17 to the branch 18 or to the branch 19. The three-way valve 23 connects the branch 17 to the outlet 6b of the radiator 6 or to the pipe 31.

Two setpoint temperatures TC1 and TC2 are provided, compared in real time to the temperature recorded by the sensor 30. The values of these thresholds are determined by the temperature which can be supported by the control unit 3 of the electric motor 2. It is possible to provide by example TC1 = 60 ° C and TC2 = 70 ° C.

In thermal mode, the heat engine 1 is in operation and drives the pump 9. The valve 16 connects the branches 17 and 18. The valve 23 connects the branch 17 and the pipe 31.

In electric mode, the mechanical pump 9 is stopped. The electric pump 21 is in operation. If the temperature measured by the sensor 30 is lower than TC1, for example in the case of a cold start, the valve 16 puts branches 17 and 19 into communication and valve 23 puts branches 17 and pipe 31 into communication It is thus possible to supply heat to the heating radiator 4 and / or to preheat the heat engine 1 in order to reduce its polluting emissions during a subsequent start-up. The rise in water temperature is effective because the water in the circuit does not pass through the radiator 6.

If the temperature measured by the sensor 30 is between TC 1 and TC 2, provision is made to cool the electric traction members and to heat the thermal traction members. The valve 16 then communicates the branches 17 and 18 and the valve 23 connects the outlet 6b of the radiator 6 and the branch 17. This always ensures a flow in the heating radiator 4 and in the heat engine 1, all by cooling the electrical components by passing through the radiator 6. If the temperature measured by the sensor 30 is greater than TC2, the valve 16 connects the branch 17 and the branch 19 and the valve 23 connects the outlet 6b of the radiator 6 and the branch 17. This thus benefits from the cooling provided by the entire radiator sized for the dissipation of heat of the traction unit constituted by the heat engine 1 and the electric motor 2.

In hybrid mode, both engines 1 and 2 are running. If the temperature measured by the sensor 30 is lower than TCl and that measured by the sensor 12 lower than the opening temperature of the thermostat 10, the control unit 3 and the electric motor 2 are cooled without running the pump 21. The valve 16 connects the branches 17 and 19 and the valve 23 connects the branch 17 and the pipe 31. This reduces the operating times of the electric pump. During a cold start, in hybrid mode, we take advantage of the heat dissipation of the electrical components to ensure a rapid rise in the temperature of the heat engine 1. This makes it possible to reduce these polluting emissions at start-up.

If the temperature measured by the sensor 30 is between TC1 and TC2, and the temperature measured by the sensor 12 lower than the opening temperature of the thermostat, the valve 16 puts branches 17 and 18 into communication and the valve 23 puts in communication the output 6b of the radiator 6 and the branch 17. The electric pump 21 is stopped. This ensures good cooling of the power electronic components of the unit 3 by circulation of the coolant throughout the radiator 6.

If the temperature measured by the sensor 30 is higher than TC2 and the temperature measured by the sensor 12 lower than the opening temperature of the thermostat, the electric pump 21 is started. Thermostat 10 being closed, we take advantage of all the radiator

6 to cool the organs of electric traction. The valve 23 connects the outlet 6b of the radiator 6 and the branch 17. The valve 16 connects the branch 17 and the branch 19. Thus, the two circuits are decoupled. The temperature of the cooling system of the electric traction units can be much lower than that of the heat engine circuit.

As a variant, provision can also be made for the valve 16 to connect the branches 17 and 18 in this way. A greater flow of water in the heat engine is thus obtained, which can favor the reduction of pollution by a rise in temperature more fast heat engine.

If the temperature measured by the sensor 12 is higher than the opening temperature of the thermostat, the electric pump 21 operates to ensure a flow rate in the branch 17. The valve 16 puts branches 17 and 18 into communication. The valve 23 turns on communication the output 6b of the radiator 6 and the branch 17.

In FIG. 11, a variant close to FIG. 10 is illustrated, except that the electric motor 2 and its control unit 3 are placed in parallel, which makes it possible to reduce the pressure losses. The valve control is identical to that of Figure 10.

In FIG. 12 is illustrated a simplified embodiment to that of FIG. 10, in which the valve 23 and the pipe 31 are eliminated. The output 6b of the radiator 6 is directly connected to the electric pump 21. It should be noted that the valve 23 is used in the previous embodiments, in electric and hybrid mode, to promote a good rise in temperature of the heat engine 1 and to possible heating of the passenger compartment. If these two functions do not have priority, one can use the embodiment of FIG. 12.

The embodiment illustrated in FIG. 13 is further simplified compared to that illustrated in FIG. 12. The branch 19 is simplified and the three-way valve 16 is replaced by a simple valve 33 which makes it possible to close and therefore to cut the communication between the branches 17 and 18. The valve 33 makes it possible to disconnect the branch from the electrical components in pure thermal mode. The preheating of the heat engine 1 and the heating of the passenger compartment are less efficient. However, if these two functions do not have priority, this embodiment is very economical due to the simplification of the cooling circuit and the simplification of the control. Only the valve 33 and the electric pump 21 must be controlled. You can always turn off the electric pump 21 during operation in hybrid mode, the thermostat 10 being closed and the temperature measured by the sensor 30 being lower than TC2.

When the mechanical pump 9 is in operation and the valve 33 in the closed position, the branch 17 does not see any circulation of coolant. The cooling of the heat engine 1 is carried out without disturbances due to the electric traction members.

When the valve 33 is in the open position, in electric mode, it authorizes the circulation of cooling fluid and the cooling of the electric motor 2 and of its control unit 3.

In hybrid mode, when the temperature measured by the sensor 30 is lower than TC2 and the temperature measured by the sensor 12 lower than the opening temperature of the thermostat, the electric pump 21 and the flow of coolant in the branch are stopped. 17 is provided by the mechanical pump 9 driven by the heat engine 1.

If the temperature measured by the sensor 30 is higher than TC2 or if the temperature measured by the sensor 12 is higher than the opening temperature of the thermostat, the electric pump 21 is started.

The embodiment illustrated in FIG. 14 is close to that illustrated in FIG. 10, except that the electric motor 2 is no longer disposed on the branch 17 but on a pipe 34 mounted parallel to the heating radiator 4. The cooling of the electric motor 2 can be ensured, either by passing the coolant between the lines 8 and 34, or by the oil of the heat engine 1. In the latter case, an oil-water temperature exchanger will be provided.

The embodiment illustrated in Figure 15 is close to that illustrated in Figure 1, except that the branch 19 is deleted. The branch 20 is connected, on the one hand, to the valve 16 and, on the other hand, to the pipe 32 between the heating radiator 4 and the heat engine 1, the temperature sensor 12 also being mounted on this part of the pipe 32.

In thermal mode, the pump 9 is on, the valve 16 connects the branches 17 and 18. The valve 23 connects the branch 17 and the branch 22. The two circuits are then decoupled. In electric mode, the mechanical pump 9 is stopped, while the electric pump 21 is in operation.

If the temperature measured by the sensor 30 is lower than TCl, the valve 16 connects the branches 17 and 20 and the valve 23 connects the branches 17 and 22. It is thus possible to heat the heating radiator 4 while ensuring a temperature rise of the heat engine 1. The temperature rise is effective because the coolant does not pass through the radiator 6.

If the temperature measured by the sensor 30 is between TC1 and TC2, the valve 16 connects the branches 17 and 20 and the valve 23 connects the outlet 6b of the radiator 6 and the branch 17. There is always a flow rate of coolant in the heating radiator 4 and in the engine 1, while cooling the electrical components by passing through the radiator 6. If the thermostat 10 opens, all of the radiator 6 is then available.

If the temperature measured by the motor 30 is higher than TC2, the valve 16 connects the branches 17 and 18 and the valve 23 connects the outlet 6b of the radiator 6 and the branch 17. The cooling of the electrical components is ensured by the third pass from the radiator 6, in other words by the part of the radiator 6 between the main output 6a and the auxiliary output 6b.

In hybrid mode, both engines 1 and 2 are running. If the temperature measured by the sensor 30 is lower than

TC l and the temperature measured by the sensor 12 lower than the thermostat opening temperature, the control unit 3 and the electric motor 2 can be cooled, with the electric pump 21 stopped. The valve 16 connects the branches 20 and 17 and the valve 23 connects the branches 17 and 22. This therefore reduces the operating time of the electric pump. During a cold start in hybrid mode, it takes advantage of the heat dissipation of the electrical members to ensure a rapid rise in the temperature of the heat engine 1 and possibly to heat the passenger compartment.

If the temperature measured by the sensor 30 is between TC1 and TC2, and the temperature measured by the sensor 12 lower than the opening temperature of the thermostat, the valve 16 puts branches 20 and 17 into communication and the valve 23 puts in communication the output 6b of the radiator 6 and the branch 17. The electric pump 21 can remain stopped.

If the temperature measured by the sensor 30 is higher than TC2, or if the temperature measured by the sensor 12 is higher than the opening temperature of the thermostat, the electric pump 21 is in operation. The valve 16 connects the branches 17 and

18 and the valve 23 connects the outlet 6b of the radiator 6 and the branch 17. If the thermostat 10 is closed, the two circuits are completely decoupled. If the thermostat 10 is open, the two circuits are pooled at the outlet of the radiator 6, on the heat engine side.

The embodiment illustrated in Figure 16 is a simplification of that of Figure 15. The valve 23 is deleted. The electric motor 2, its control unit 3, the temperature sensor 30 and the electric pump 21 are mounted in series on the branch 18. The branch 17 directly connects the outlet 6b of the radiator 6 and the valve 16.

In thermal mode, the valve 16 communicates the branches 17 and 18.

In electric mode, when the temperature measured by the sensor 30 is lower than the set temperature TC2, the valve

16 connects the branches 20 and 17. The dissipation of heat from the electrical members is therefore used to heat the heat engine 1 and the heating radiator 4. As soon as the temperature measured by the sensor 11 becomes higher than the temperature TC2, the valve 16 connects the branches 17 and 18, which allows cooling of the electrical components with a good flow rate in the third pass of the radiator 6.

In hybrid mode, when the temperature measured by the sensor 30 is lower than TC2, the valve 16 connects the branches 20 and 18. It is thus possible to stop the electric pump 21 and use the heat given off by the electric members to heat the cockpit and ensure the temperature rise of the heat engine 1. As soon as the temperature measured by the sensor 30 is higher than the temperature TC2, the electric pump 21 is started and the valve 16 puts branches 17 and 18 into communication.

In FIG. 17, a valve 16 is represented schematically. The valve 23 can be of the same type. The valve 16 has a cylindrical body 35 inside which is mounted a movable element 36 comprising a central core 37 and arms 38 and 39. The movable element 36 is rotated by an electric motor.

The coolant circulates in the annular space between the central hub 37 and the body 35. As shown in FIG. 17, the valve 16 is in a position allowing the circulation of fluid between the branches 18 and 19 and preventing the circulation of fluid in branch 17. The passage of the coolant takes place as in a tube bent at 120 ° angle. The pressure drop is extremely low.

The embodiments in which the thermostat is placed upstream of the heat engine make it possible, in certain operating modes, to cut the power supply to the electric pump, in particular in hybrid mode, thermostat closed. The mechanical pump driven by the heat engine ensures the circulation of coolant in the radiator, then in the electric traction units, through the stopped electric pump. The two cooling circuits, that of the heat engine and that of the electric motor, are coupled when the temperature in the components is low and the thermostat is closed. The circulation of the coolant is ensured by one of the two pumps. In electric mode, the electric pump ensures a flow in all the branches of the circuit. In hybrid mode, the mechanical pump driven by the heat engine allows the circulation of coolant in all the organs of the circuit. As soon as the temperature in the electrical components reaches a determined value, the management of the cooling circuit, via the sensors and the control acting on the valves, allows the decoupling of the high-temperature circuit from the heat engine and the circuit to low temperature of the electric traction components.

The temperature of the coolant, at the inlet of the electrical traction members, is very low in all operating cases where said members dissipate heat in the cooling circuit. The electric pump works less often, resulting in reduced energy consumption and the possibility of using conventional technology pumps, at low cost and whose lifespan is greater than or equal to that of the vehicle.

In all-electric mode, the dissipation of heat by the electric traction units can be used to increase the temperature of the heat engine and also to heat the passenger compartment.

Claims

1. Cooling device (6) of a heat transfer fluid by heat exchange with another fluid, comprising an inlet (27) and an outlet (6a) of heat transfer fluid, characterized in that it comprises an auxiliary outlet (6b ) so that the heat transfer fluid from the auxiliary outlet is at a temperature lower than that of the main outlet.

2. Device according to claim 1, characterized in that it comprises a first portion arranged between the inlet and the main outlet and a second portion disposed between the inlet and the auxiliary outlet, the two portions being integrated into a body of radiator.

3. Device according to claim 1 or 2, characterized in that the main outlet and the auxiliary outlet are arranged at opposite ends of the device.

4. Device according to claim 1 or 2, characterized in that the main output and the auxiliary output are arranged at the same end of the device.

5. Cooling system for a hybrid propulsion vehicle comprising a heat engine (1) and at least one electric motor (2), of the type comprising a heat transfer fluid capable of cooling the heat and electric motors, a radiator (6) capable of cooling the heat transfer fluid by heat exchange with an air stream and comprising a plurality of cooling channels, an inlet and an outlet, a first pipe (7) between the outlet of the radiator and the heat engine and a second pipe (8) between said heat engine and the radiator inlet, characterized in that the radiator (6) comprises an auxiliary outlet (6b) so that the heat transfer fluid from the auxiliary outlet is at a temperature lower than that of the main outlet (6a) connected to the first pipe, said auxiliary outlet being connected to a bypass pipe (15) capable of cooling the electric motor.

6. System according to claim 5, characterized in that that the bypass pipe comprises a first branch (17) connected to the auxiliary output and a second branch (18) connected to a pipe upstream of the engine.

7. System according to claim 5 or 6, characterized in that the first branch (17) is adapted to be connected to the first pipe (7).

8. System according to any one of claims 5 to 7, characterized in that the bypass pipe comprises a third branch (19) connected to the second pipe.

9. System according to any one of claims 5 to 8, characterized in that the bypass pipe comprises a fourth branch (20) connected to the outlet of the heat engine upstream of a thermostat (10).

10. System according to any one of claims 5 to 9, characterized in that the branches of the bypass pipe are connected to each other by a multi-way valve (16).

1 1. System according to any one of claims 5 to 8, characterized in that it comprises a thermostat disposed on the first pipe (7), the thermostat being able to close the first pipe (7), a connected pipe the electric motor (2) being able to be in communication with the heat engine (1).

12. System according to claim 11, characterized in that it comprises a first valve (16) capable of putting the output of the electric motor (2) into communication with at least the heat engine (1)

13. System according to claim 1 1, characterized in that the first valve is of the multi-channel type and is capable of putting the output of the electric motor (2) into communication with the heat engine (1) or with the second pipe (8 ).

14. System according to any one of claims l i a

13, characterized in that it comprises a second valve (23) able to put the auxiliary output (6b) into communication at least with the electric motor (2).

15. System according to claim 14, characterized in that the second valve is of the multi-channel type and is able to set up communication of the auxiliary output (6b) with the electric motor (2) or with the heat engine (1).

16. System according to any one of claims 5 to 15, characterized in that the electric motor (2) is mounted on a bypass pipe parallel to the heat engine (1).

17. System according to any one of claims 5 to 16, characterized in that said auxiliary output is connected to a bypass pipe capable of cooling an electronic control unit (3).

18. Vehicle comprising a system according to any one of claims 5 to 17.

19. A cooling method for a hybrid propulsion vehicle comprising a heat engine and at least one electric motor cooled by the circulation of a heat transfer fluid in said engines, a heat exchange means capable of cooling the heat transfer fluid by heat exchange with a other fluid and provided with an inlet and an outlet, in which the flow of heat transfer fluid is divided in the heat exchange means between a main outlet and an auxiliary outlet so that the heat transfer fluid from the auxiliary outlet has a temperature lower than that of the main outlet, said auxiliary outlet being connected to a bypass pipe capable of cooling the electric motor.