MAGNETIC COUPLING TURBOGENERATOR

Abstract

The present invention relates to an assembly comprising two radial compressors (C1, C2) and two radial turbines (T1, T2), characterized in that it comprises a single electric generator (EG) and magnetic coupling means for rotational drive between the electric generator (EG) and the compressors (C1, C2) and between the electric generator (EG) and the turbines (T1, T2). Figure 1

Description

Title of the invention: MAGNETIC COUPLING TURBOGENERATOR

[0001] The invention relates to a thermodynamic system employing several turbomachines. This system is particularly intended for hybrid vehicles.

[0002] In order to reduce polluting emissions from motor vehicles, it is known in the prior art to incorporate a gas turbine into the propulsion systems of hybrid vehicles. Hybrid vehicles use either energy from an internal combustion engine, fueled by a product such as diesel, gasoline, ethanol, methanol, or natural gas, or electrical energy to move. Electrical energy can be directly produced by a power generation system integrated into the vehicle or from the vehicle's integrated battery. Some hybrid vehicles are also plug-in hybrids. Turbogenerators, for example, composed of a gas turbine and an electricity generator, thus produce this electrical energy and reduce emissions of carbon dioxide and other air pollutants such as nitrogen oxides.The Brayton cycle is a thermodynamic cycle using a gas turbine. It exhibits remarkable performance in terms of reducing pollutant emissions. Some thermodynamic cycles of these converters, comprising several compression and expansion stages, allow for very high efficiencies and power densities. These architectures are bulky, and in the automotive sector, where compactness is paramount, this architecture needs to be redesigned.

[0003] The aim of the invention is therefore to overcome the disadvantages of the prior art by proposing a thermodynamic system for the production of electricity, in particular for vehicles, which is lighter and occupies less space than conventional systems.

[0004] To achieve this objective, the invention provides an assembly comprising two radial compressors, two radial turbines, characterized in that it comprises a single electric generator and magnetic coupling means for rotational drive between the electric generator and the compressors and between the electric generator and the turbines.

[0005] The technical effect is to obtain a compact turbogenerator with only one electrical machine and less complex.

[0006] Various additional features may be provided, alone or in combination:

[0007] According to one embodiment, the magnetic coupling means for the drive in rotations are composed of two distinct magnetic coupling means and include: -a sub-assembly comprising the two turbines and the first magnetic coupling means on the same axis of rotation, -a sub-assembly comprising the two compressors and the second magnetic coupling means on the same axis of rotation.

[0008] According to one embodiment, the magnetic coupling means for rotational drive are composed of two separate magnetic coupling means and in that it comprises two sub-assemblies each comprising a compressor, a turbine and a magnetic coupling means on the same axis of rotation.

[0009] According to one embodiment, for each sub-assembly the magnetic coupling means is arranged so that the compressor is between the magnetic coupling means and the turbine.

[0010] According to one embodiment, for each sub-assembly the magnetic coupling means is disposed between the compressor and the turbine.

[0011] According to one embodiment, all the turbines and all the compressors are independent and each has a separate axis of rotation, a separate magnetic coupling means being mounted on each axis of rotation, and driving a ring which is coupled to the electric generator, the ring being internal or external to the magnetic coupling means.

[0012] The invention also relates to a machine, characterized in that it comprises an assembly according to one of the variants described above, -a cooler, a regenerator, two combustion chambers, -the cooler being connected between an air outlet of the first of the two compressors and an air inlet of the second of the two compressors, to cool the air coming from the first of the two compressors, -the regenerator being an air / combustion gas heat exchanger connected between an air outlet of the second of the two compressors and an air inlet of the first of the two combustion chambers, -the first of the two combustion chambers being connected between an air outlet of the regenerator and an inlet of the first of the two turbines, -the second of the two combustion chambers being connected between an outlet of the first of the two turbines and an inlet of the second of the two turbines, -the output of the second of the two turbines being connected to a combustion gas inlet of the regenerator.

[0013] According to one embodiment, the compressors and the cooler are grouped in a first zone called the cold zone, while the turbines, the combustion chambers and the recuperator are grouped in a second zone called the hot zone.

[0014] The invention also relates to a motor vehicle comprising such a machine.

[0015] Other features and advantages will become apparent from the following description of a particular, non-limiting embodiment of the invention, made with reference to the figures in which:

[0016] [Fig.l]: schematically represents a first example of an embodiment according to the invention.

[0017] [Fig.2]: schematically represents another example of an embodiment according to the invention.

[0018] [Fig.3]: schematically represents another example of an embodiment according to the invention.

[0019] [Fig.4]: schematically represents another example of an embodiment according to the invention.

[0020] [Fig.5]: schematically represents another example of an embodiment according to the invention.

[0021] [Fig.6]: schematically represents another example of an embodiment according to the invention.

[0022] [Fig.7]: schematically represents another example of an embodiment according to the invention.

[0023] The invention consists of proposing a turbogenerator-type energy converter based on a gas turbine cycle with an architecture of two separate turbochargers but using magnetic coupling in order to utilize a single electric generator. The aim is therefore to have two separate turbomachines and to couple their shafts to a single generator to recover power. Several configurations will be detailed.

[0024] Fig. 1 represents a first embodiment of a machine according to the invention.

[0025] According to this embodiment, the machine comprises two radial compressors: a first radial compressor C1 and a second radial compressor C2. The machine also comprises two radial turbines: a first radial turbine T1 and a second radial turbine T2. A radial compressor is a compressor in which the working fluid, most often air, enters along the axis of rotation of the compressor and exits compressed in a direction radial to the axis of rotation. A radial turbine is a turbine in which the working fluid, most often combustion gases, enters in a direction radial to the axis of rotation and exits expanded along the axis of rotation of the turbine.

[0026] In the following description, compressor C1 is the compressor of the low-pressure compression stage, while compressor C2 is the compressor of the high-pressure compression stage. Turbine T1 is the turbine of the high-pressure stage. of the expansion stage, while turbine T2 is the turbine of the low-pressure expansion stage.

[0027] As illustrated in [Fig.1], the machine further comprises a single electric generator EG and means for magnetic couplings for rotational drive between the electric generator, EG and the compressors Cl, C2 and between the electric generator, EG and the turbines Tl, T2.

[0028] In this first architecture, shown in [Fig. 1], the turbines T1, T2 are grouped on the same axis, 1a, and the compressors C1, C2 are grouped on the same axis, 1b. A magnetic coupling means, M1m, M2m, is added to each axis, 1a, 1b, each positioned between a compressor and a turbine. The turbines T1, T2 produce power, and the compressors C1, C2 consume energy to compress; thus, the electric machine EG is driven via the magnetic coupling means, M1m, on the turbine axis 1a, and the electric machine EG, in turn, drives the compressors C1, C2, the other magnetic coupling means, M2m, on the compressor axis 1b.

[0029] With regard to magnetic coupling, several systems also exist. Magnetic systems, whether permanent magnet or electromagnetic, allow, through magnetic coupling, the performance of functions that are usually mechanical. This magnetic coupling offers numerous advantages:

[0030] -The generated function (attraction force, guidance, braking) does not induce contact between the different parts of the systems. This characteristic does not cause wear on the parts.

[0031] -Magnetic coupling is a clean technology (no grease, no filings...).

[0032] -The flexibility of the magnetic coupling can be adjusted and allows for the absorption of unwanted vibrations.

[0033] -The maintenance of magnetic systems is almost zero.

[0034] -The sealing of these equipment is total because the transmission of the function can be done without contact through a sealed wall.

[0035] -These systems are insensitive to pressure variations, unlike pneumatic systems.

[0036] As further illustrated in [Fig. 1], the machine includes a compressed air inlet EA1 leading to the first compressor CL. The first compressor CL includes a compressed air outlet SA1 connected to an inlet of a heat exchanger IC designated as a cooler, as its function is to cool the compressed air exiting compressor CL. The outlet of the cooler IC is connected to an air inlet EA2 of the second compressor C2. The second compressor C2 includes a compressed air outlet SA2 connected to an inlet of a regenerator R. A regenerator is a heat exchanger between air and combustion gases that allows the air exiting the second compressor C2 to be reheated with the remaining heat in the exhaust gases. of the T2 turbine.

[0037] The air outlet of the regenerator R is connected to an inlet of a first combustion chamber CCI. The outlet of the first combustion chamber CCI is connected to a combustion product inlet EC1 of the first turbine TL. The first turbine TL includes a combustion product outlet SCI connected to the inlet of a second combustion chamber CC2. The outlet of the second combustion chamber CC2 is connected to a combustion product inlet EC2 of the second turbine T2. The second turbine T2 includes an outlet SC2 connected to the regenerator R to preheat the air entering the first combustion chamber CCI.

[0038] Thus, air enters through compressor C1, which compresses the air, thereby increasing its pressure and temperature. The air then enters cooler IC, which expels heat to the ambient air if it undergoes heat exchange with it. At the outlet of cooler IC, the air is still at high pressure, but it is cooled. This air then undergoes a second compression in the second compressor C2. At the outlet of the second compressor C2, the air is preheated in regenerator R and then enters the first combustion chamber C1 where combustion takes place. At the outlet of the first combustion chamber C1, the combustion products enter the first turbine T1 and undergo a first expansion, then pass back into the second combustion chamber CC2 where a second combustion takes place; this is called afterburning.The gases exiting the second combustion chamber pass into the second turbine T2, which expands the combustion products to approximately atmospheric pressure. Exiting the second turbine T2, the gases are still hot and pass into the hot side of the regenerator R to preheat the air entering the first combustion chamber CCI.

[0039] The operation of this machine described in [Fig.1] is based on a thermodynamic cycle called IRRGT for "Intercooled Regenerative Reheat Gas Turbine" in English, allowing to obtain significant efficiencies as well as high power densities.

[0040] In this configuration, the compressors Cl, C2 and the cooler, IC are physically grouped together, while the turbines Tl, T2, the combustion chambers CCI, CC2 and the recuperator R are physically grouped together. The elements are thus separated into two zones, one cold and the other hot.

[0041] Figure 2 presents another example of an embodiment. This example of an embodiment differs from the embodiment of Figure 1 in that it presents a first sub-assembly comprising a compressor, C1, a turbine T2, a magnetic coupling means Mam1 on the same axis of rotation 1a and a second sub-assembly comprising a compressor, C2, a turbine T1, a magnetic coupling means Mam2 on the same axis of rotation 1b.

[0042] Furthermore, in this embodiment example, for each sub-assembly, the magnetic coupling means Maml, Mam2 is arranged so that the compressor is between the magnetic coupling means and the turbine of the sub-assembly.

[0043] In this architecture shown in [Fig. 2], the turbochargers are mounted on the same shaft (compressor + associated turbine) and the electric machine is on the side of compressors C1 and C2, in order to reduce thermal stress. In this architecture, compressor C1 is connected to turbine T2 (low-pressure stage together) while compressor C2 is connected to turbine T1 (high-pressure stage together).

[0044] Figure 3 presents another embodiment. This embodiment differs from the embodiment of Figure 2 in that in this architecture compressor Cl is connected to turbine T1 while compressor Cl is connected to turbine T2.

[0045] Figure 4 presents another embodiment. This embodiment differs from that of Figure 2 in that, in this architecture, the turbochargers are mounted on the same axes (compressor + associated turbine), and the magnetic coupling means, Maml, Maml, is located between the compressor and the turbine. The electric machine EG is thus driven by the magnetic coupling means, Maml, Maml, of the two axes 1a, 1b. In this architecture, compressor C1 is connected to turbine T2 (low-pressure stage together), while compressor C2 is connected to turbine T1 (high-pressure stage together).

[0046] Figure 5 presents another example of an embodiment. This example of an embodiment differs from the embodiment of Figure 4 in that in this architecture compressor Cl is connected to turbine T1 while compressor Cl is connected to turbine T2.

[0047] Figure 6 presents another embodiment. In this embodiment, all the turbines T1, T2 and all the compressors C1, C2 are independent and each has a separate axis of rotation. On each axis of each machine, a magnetic coupling means is mounted: Mam_Cl on compressor C1, Mam_C2 on compressor C2, Mam_T1 on turbine T1, and Mam_T2 on turbine T2. These magnetic coupling means drive a ring C, which is coupled to the electric machine EG. This ring may be inside or outside the magnetic coupling means Mam_Cl, Mam_C2, Mam_T1, and Mam_T2, as illustrated in Figure 7.

[0048] The embodiments present a machine whose compact architecture allows it to be mounted in a vehicle, such as a motor vehicle.

[0049] Our invention makes it possible to reduce the complexity of a turbogenerator (or gas turbine) system and to offer a more compact and less expensive architecture with only a single electric machine. Indeed, it is sufficient to put a ma- coupling genetics on the axes of the turbochargers and to drive the electric generator.

[0050] This therefore makes it possible to reduce the complexity of the system, minimize the overall volume, and have greater flexibility in the operating points of the machines. Thus, the reduction ratios can be adapted according to the turbomachinery.

[0051] The magnetic system makes it possible to do away with gears and other systems which have the disadvantages of noise, the need for a lubrication system and friction.

[0052] All these advantages are beneficial for optimizing a turbogenerator designed to be integrated into an automotive powertrain.

Claims

Demands

1. Assembly comprising: -two radial compressors (Cl, C2), -two radial turbines (Tl, T2), characterized in that it comprises a single electric generator (EG) and means for magnetic couplings for rotational drive between the electric generator (EG) and the compressors (Cl, C2) and between the electric generator (EG) and the turbines (Tl, T2), the means for magnetic couplings for rotational drive being composed of two distinct magnetic coupling means (Maml; Mam2), in that it comprises two subassemblies each comprising a compressor, a turbine and a magnetic coupling means on the same axis of rotation, for each subassembly the magnetic coupling means (Maml; Mam2) being disposed between the compressor and the turbine.

2. A machine, characterized in that it comprises: - an assembly according to claim 1, - a cooler (IC), a regenerator (R), two combustion chambers (CCI, CC2), - the cooler (IC) being connected between an air outlet (SA1) of one of the two compressors and an air inlet (EA2) of the second of the two compressors, to cool the air from the first of the two compressors, - the regenerator (R) being an air / combustion gas heat exchanger connected between an air outlet (SA2) of the second of the two compressors and an air inlet of the first of the two combustion chambers (CCI), - the first of the two combustion chambers (CCI) being connected between an air outlet of the regenerator (R) and an inlet (EC1) of the first of the two turbines, - the second of the two combustion chambers (CC2) being connected between an outlet (SCI) of the first of the two turbines (T1) and an inlet (EC2) of the second of the two turbines (T2),-the outlet (SC2) of the second of the two turbines (T2) being connected to a combustion gas inlet of the regenerator (R).

3. Motor vehicle, characterized in that it comprises a machine according to claim 2.

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