ELECTRICITY PRODUCTION DEVICE COMPRISING AN IRRegT CYCLE TURBOGENERATOR

Abstract

The invention relates to an electricity production device comprising an IRReGT cycle turbogenerator (100) with separate low pressure (151) and high pressure (152) stages, a cooling exchanger (105) for cooling a gas flow between low pressure (101) and high pressure (102) compressors, a heat recovery unit (106) between the high pressure compressor (102) and a high pressure combustion chamber (107) driving a high pressure turbine (103) supplying a low pressure combustion chamber (108) driving a low pressure turbine (104), this turbogenerator (100) comprising a single electrical machine (120) driven by at least one additional turbine (130; 140) driven by a gas flow from the low pressure (104) or high pressure (103) turbine. Figure 5

Description

Title of the invention: ELECTRICITY PRODUCTION DEVICE COMPRISING AN IRReGT CYCLE TURBOGENERATOR

[0001] The invention relates to an electricity production device comprising at least one IRReGT cycle turbogenerator with recovery and intermediate cooling and intermediate reheating, said turbogenerator being a double-stage turbomachine with recovery and intermediate cooling, with a separate low-pressure stage and a separate high-pressure stage, said turbogenerator comprising a low-pressure compressor linked to a low-pressure turbine by a low-pressure shaft, a high-pressure compressor linked to a high-pressure turbine by a high-pressure shaft, at least one first cooling exchanger arranged to cool the gas flow between said low-pressure compressor and said high-pressure compressor,a heat recovery unit between said high pressure compressor and a high pressure combustion chamber arranged to drive said high pressure turbine which feeds a low pressure combustion chamber driving said low pressure turbine.

[0002] The invention also relates to an electric or hybrid motor vehicle comprising at least one such electricity production device.

[0003] The invention also relates to a stationary system comprising at least one such electricity production device.

[0004] The invention relates to the fields of turbogenerators, gas turbines, micro-turbines, and the optimized application of different thermodynamic cycles, Brayton cycle, gas turbine cycle, as well as the integration of electrified turbines known as "e-turbines".

[0005] Gas turbine type energy converters are currently being widely studied as a range extender in series hybrid vehicles. Such a converter operates in APU (Auxiliary Power Unit) mode, where its role is to recharge the batteries of an electric or hybrid vehicle. It is thus mechanically decoupled from the powertrain and thus operates at its maximum efficiency point.

[0006] Several cycles are being investigated, including among them simple recuperative cycles (RGT = Recuperative Gas Turbine), and also IRReGT cycles (Intercooled Recuperative Gas Turbine).

[0007] The gas turbine cycle with cooler, recuperator and reheat exchanger (Intercooled Regenerative Reheat Gas Turbine IRReGT), with recovery and intermediate cooling and intermediate reheating, is a cycle with high potential, in particular particular and not limited to automotive applications. This cycle makes it possible to achieve a very high efficiency, and also a very high power density (high net specific work), as shown by the comparison between a simple gas turbine called GT, a cycle with recuperator called RGT, a cycle with a cooler exchanger and IRGT recuperator and the IRReGT, where we see the preponderance of the IRReGT cycle in terms of efficiency and net specific work. The cooler exchanger is supplied with gas or liquid from a heat transfer circuit and arranged to cool the gases between a first low pressure compressor and a second high pressure compressor

[0008] Note that the RGT cycle requires one combustion chamber, while the IRReGT cycle requires two combustion chambers.

[0009] Installing the combustion chamber in the recuperator allows for greater integration.

[0010] It is understood that the implementation of an IRReGT cycle is generally done with a device comprising two electrical machines. The use of two electrical machines, and consequently the use of two power electronics, complicates the system and makes it expensive.

[0011] It is therefore interesting to seek solutions implementing a single electrical machine.

[0012] A known alternative is to put the two e-turbomachines (each comprising compressor + turbine + electric machine) in line, with a low pressure stage and a high pressure stage as in an aircraft reactor. But in this case, the shaft of the turbomachine becomes long, and there are hot inlets / outlets on both sides, which limits this solution to static industrial applications, or to heavy goods vehicles.This aligned configuration does indeed have some disadvantages: the shaft that connects the low pressure compressor to the high pressure turbine is long, which causes vibration problems at high speeds, the machine is bulky, it is necessary to ensure a high pressure seal at the inlet of the high pressure compressor because the flow is compressed to 3 bars, as well as a high pressure and high temperature seal at the outlet of the high pressure turbine, a high pressure and high temperature seal at the inlet of the low pressure turbine, and the recuperator and cooler exchanger components are bulky because the circuit between them is open and there is air passing through (therefore less efficient) for heat exchanges.

[0013] The aim is to develop a turbomachine that is less expensive and less bulky than those of the prior art, and preferably by reducing or completely avoiding carbon emissions.

[0014] Also, the invention proposes to develop a turbomachine, in particular operating according to an IRReGT cycle, comprising a single electric machine coupled to at least two turbines, or even more if the cycle requires more than two stages.

[0015] This proposition is valid for any turbomachine comprising at least one turbine (RGT, RReGT, IRGT, IRReGT).

[0016] Thus, in a preferred form, the invention consists of proposing a turbogenerator operating according to the IRReGT Intercooled Recuperative Reheat Gas Turbine thermodynamic cycle, with a single electrical machine coupled to at least two expansion turbines, which expansion turbines make it possible to recover the excess power generated by each turbocharger (compressor + turbine).

[0017] The proposed turbogenerator technology is very promising for replacing the internal combustion engine in highly electrified powertrains, particularly for PHEV (Plug-in Hybrid Electric Vehicles) vehicles with series hybrid architecture (Series Hybrid Electric Vehicles).

[0018] This technology promises the following advantages: low emissions, low noise, no vibrations, very low maintenance (limited to changing the oil filter), ability to operate with several types of fuel.

[0019] The invention proposes a double or triple stage machine architecture, with only one electric machine coupled to the expansion turbines.

[0020] To achieve this objective, the invention proposes an electricity production device comprising at least one IRReGT cycle turbogenerator with recovery and intermediate cooling and intermediate reheating, the turbogenerator being a double-stage turbomachine with recovery and intermediate cooling, with a separate low-pressure stage and a separate high-pressure stage, the turbogenerator comprising a low-pressure compressor linked to a low-pressure turbine by a low-pressure shaft, a high-pressure compressor linked to a high-pressure turbine by a high-pressure shaft, at least one first cooler exchanger arranged to cool the gas flow between the low-pressure compressor and the high-pressure compressor,a heat recovery unit between the high pressure compressor and a high pressure combustion chamber arranged to drive the high pressure turbine which feeds a low pressure combustion chamber driving the low pressure turbine.

[0021] According to the invention, the turbogenerator comprises a single electrical machine driven by at least one additional turbine driven by a gas flow from the low pressure turbine or by a gas flow from the high pressure turbine.

[0022] Thanks to the invention, an electrical machine is saved, and the volume of the electricity production device according to the invention is drastically reduced.

[0023] More particularly, the turbogenerator comprises a single electrical machine driven by an upstream expansion turbine driven by a gas flow from the high pressure turbine, and by a downstream expansion turbine driven by a gas flow from the low pressure turbine.

[0024] This arrangement only requires the addition of two turbines, which are much less costly than the second electric machine that the invention makes it possible to eliminate.

[0025] More particularly still, the power of the low pressure turbine is equal to the power of the low pressure compressor, the excess power being recovered on the downstream expansion turbine, and the power of the high pressure turbine is equal to the power of the high pressure compressor, the excess power being recovered on the upstream expansion turbine.

[0026] The yield is thus optimized.

[0027] More particularly, the turbogenerator comprises a third very high pressure stage with a very high pressure compressor driven by a very high pressure turbine via a very high pressure shaft, a second exchanger between the high pressure compressor and the very high pressure compressor, an additional combustion chamber between the downstream expansion turbine and the low pressure turbine, and an additional turbine coupled to the downstream expansion turbine and powered by the low pressure turbine.

[0028] The yield is thus further improved.

[0029] The invention also relates to an electric or hybrid motor vehicle comprising at least one such electricity production device.

[0030] This provides a device for extending autonomy with a controlled cost and a small footprint.

[0031] The invention also relates to a stationary system comprising at least one such electricity production device.

[0032] This provides an energy production device with controlled cost, small footprint, compact and capable of being easily implemented on construction sites or humanitarian or other operations.

[0033] The invention will be further detailed by the description of non-limiting embodiments, and on the basis of the appended figures illustrating variants of the invention, in which: - [Fig.l] schematically illustrates a user system incorporating an electricity generation device according to the invention, in a first variant where this user system is stationary; - [Fig.2] schematically illustrates a user system incorporating a electricity generation device according to the invention, in a second variant where this user system is mobile, in particular a vehicle electric or hybrid car; - [Fig.3] schematically illustrates the architecture of a double-stage turbogenerator with IRReGT thermodynamic cycle, where the low-pressure stage and the high-pressure stage are on the same rotation axis; - [Fig.4] schematically illustrates the architecture of a double turbogenerator IRReGT thermodynamic cycle stage, the low pressure stage and the high pressure stage being separated, and comprising, respectively, a low pressure electric machine and a high pressure electric machine; - [Fig.5] schematically illustrates the invention, applied to the IRReGT thermodynamic cycle double-stage turbogenerator shown in [Fig.4], which is modified by the removal of the low-pressure electrical machine of the low-pressure stage and the high-pressure electrical machine of the high-pressure stage, and by the insertion of two turbines, an upstream expansion turbine and a downstream expansion turbine. The upstream expansion turbine is driven by the gas flow from the high-pressure turbine, downstream of the high-pressure combustion chamber, and the gas flow leaving the upstream expansion turbine feeds the low-pressure combustion chamber, for driving the low-pressure turbine. While the gas flow from the low-pressure turbine drives the downstream expansion turbine, downstream of which the gas flow passes through an exchanger linked to the heat recovery unit before returning to the low-pressure compressor.The upstream expansion turbine and the downstream expansion turbine are associated with a single electrical machine, which is now the only one included in the turbogenerator; . - [Fig.6] schematically illustrates a turbogenerator comprising a third stage.

[0034] Illustrated in [Fig.l] is a user system 1000 incorporating an electricity generation device according to the invention, in a first variant where this user system is stationary. The electricity generation device is an autonomous device which comprises at least one energy converter of the gas turbine type, which is IRReGT cycle, and comprises at least one turbogenerator 100 with recovery and intermediate cooling. This at least one turbogenerator 100 is in particular powered by a fuel tank 7000, and is arranged for recharging with energy at least one battery pack 2000 of an industrial installation or similar, and / or for powering at least one electric motor of an industrial installation comprising the electricity production system 1000, or any other electrical energy consuming organ.The concept of "industrial installation" should be taken in the broad sense, because one of the advantages of the invention lies in the very small footprint that the electricity production system 1000 can occupy: by . For example, domestic, agricultural, craft, or other applications are likely to implement the invention, and in particular wherever the supply of electrical energy is too low, too expensive, or even non-existent.

[0035] Illustrated in [Fig.2] is a user system 5000 incorporating an electricity generation device according to the invention, in a second variant where this user system 5000 is mobile, in particular an electric or hybrid motor vehicle, here a battery-electric motor vehicle, which comprises at least one battery pack 2000 for powering an electric traction motor, this at least one battery pack 2000 being in particular and not limited to being housed under a floor or under a trunk that this electric motor vehicle 1000 comprises.

[0036] This user system 1000 comprises an electricity generation device according to the invention, which comprises at least one turbomachine which is powered by a fuel tank 7000. In the second variant of [Fig.2], this at least one turbomachine is arranged for recharging this at least one battery pack 2000 with energy.

[0037] Advantageously, this turbomachine is an IRReGT cycle and comprises at least one turbogenerator 100 with recovery and intermediate cooling.

[0038] The prior art is illustrated by [Fig.3] and [Fig.4], where this electricity generation device comprises a two-stage turbogenerator, and, preferably due to its good efficiency, at least one such turbomachine comprises a turbogenerator 100 which is a micro-turbine operating with a liquid or gaseous fuel, with two stages of recovery and intermediate cooling.

[0039] The innovation is advantageously applied to an energy converter of the turbogenerator type with an intercooled recuperative reheat gas turbine (IRReGT) thermodynamic cycle, i.e. a turbogenerator with recovery and intermediate cooling. Compared to an RGT cycle (Recuperative Gas Turbine / Simple turbine cycle), the turbogenerator operates according to the IRReGT cycle, it is a double-stage machine making it possible to achieve a higher efficiency and a higher power density. If the RGT cycle (Recuperative gas turbine), also applicable to the invention, requires a single combustion chamber, the IRReGT cycle requires two combustion chambers, as seen in [Fig.3] and [Fig.4], but its efficiency is much higher than that of an RGT cycle.

[0040] More particularly, in the case where the working fluid is air, at least one such turbomachine comprises a turbogenerator 100 which comprises at least one air filter 109, a first electrified turbocharger 151 for a low pressure stage comprising a low pressure compressor 101, a low pressure turbine 104, and a first electric machine 121 equipped with a first inverter, a second electrified turbocharger 152 for a high pressure stage comprising a high pressure compressor 102, a high pressure turbine 103, and a second electrical machine 122 equipped with a second inverter, at least one heat recovery unit 106 by heat exchange between the air and the exhaust gases, at least one first cooling exchanger 105, called intercooler, supplied with ambient air and arranged to cool the air between this low pressure compressor 101 and this high pressure compressor 102 through a heat transfer circuit with water or air or other fluid as refrigerant. The exhaust gases are guided to the outside by at least one exhaust pipe.

[0041] More particularly still, at the outlet of the high pressure compressor 102, such a heat recovery unit 106 is inserted before the gases enter an HP combustion chamber 107 which is arranged to drive the high pressure turbine 103, and an LP combustion chamber 108 is inserted between the high pressure turbine 103 and the low pressure turbine 104, and is arranged to drive the low pressure turbine 104.

[0042] [Fig.3] shows an IRReGT 100 turbogenerator, in the particular case of a coaxial machine, where coaxial shafts 110 each connect a compressor and a turbine, respectively low pressure (LP): LP compressor 101 and LP turbine 104, and high pressure (HP): HP compressor 102 and HP turbine 103. A first re-cooler exchanger 105, supplied with ambient air or another heat transfer fluid such as water or other, cools the air between the LP compressor 101 and the HP compressor 102. At the outlet of the HP compressor 102 a recuperator 106 is inserted before the entry into an HP combustion chamber 107 which drives the HP turbine 103. The objective of the recuperator 106 is to increase the air temperature at the inlet of the HP combustion chamber 107 by preheating the air. A BP 108 combustion chamber is inserted between the HP 103 turbine and the BP 104 turbine, to supply the latter.

[0043] The large size of such a coaxial machine encourages the implementation of a much more compact separate-stage machine. The difficulties explained above, relating to putting the two e-turbomachines online (each comprising a compressor + turbine + electric machine) lead to decoupling the two turbomachines and having two separate spools (a spool is a set comprising a compressor + electric machine + turbine), according to [Fig.3]. A low pressure LP spool comprises a LP compressor, a LP electric machine and a LP turbine. A high pressure HP spool comprises an HP compressor, an HP electric machine, and an HP turbine. This IRReGT cycle then requires two electric machines: a first electric machine 121 equipped with a first inverter, and a second electric machine 122 equipped with a second inverter, and therefore two power electronics cards, which increases the price of the machine.

[0044] [Fig.4] thus shows an IRReGT 100 turbogenerator, in the particular case of a machine with two separate stages: a low pressure stage 151 (hereinafter LP) and a high pressure stage 152 high pressure (hereinafter HP). In the low pressure stage 151, a first shaft 111 connects a LP compressor 101 (which receives the air via an air filter 109) and a LP turbine 104. In the high pressure stage 152, a second shaft 112 connects an HP compressor 102 and an HP turbine 103. A first re-cooler exchanger 105, supplied with ambient air, cools the air between the LP compressor 101 and the HP compressor 102. At the outlet of the HP compressor 102, a heat recovery unit 106 is inserted before the entry into an HP combustion chamber 107 which drives the HP turbine 103. A LP combustion chamber 108 is inserted between the HP turbine 103 and the LP turbine 104, to supply the latter, the gases exiting through the heat recovery unit 106.In this variant, the low pressure stage 151 and the high pressure stage 152 are separated, which is well suited to installation in a reduced volume, and makes it possible to reduce the size of the pipes required for conveying the different fluids. And the modularity of this turbogenerator makes it possible to position its components in different locations depending on the space available.

[0045] However, the problem of the cost of the two electric machines and their equipment remains.

[0046] The invention consists of developing a solution making it possible to limit oneself to a single electrical machine.

[0047] [Fig.5] illustrates the invention, applied to the IRReGT thermodynamic cycle double-stage turbogenerator shown in [Fig.4], which is modified by the removal of the low-pressure electrical machine 121 from the low-pressure stage 151, and of the high-pressure electrical machine 122 from the high-pressure stage 152, and by the insertion of two additional expansion turbines, an upstream expansion turbine 130 and a downstream expansion turbine 140. The upstream expansion turbine 130 is driven by the gas flow from the high-pressure turbine 103, downstream of the high-pressure combustion chamber 107, and the gas flow leaving the upstream expansion turbine 130 feeds the low-pressure combustion chamber 108, for driving the low-pressure turbine 104.The gas flow from the low-pressure turbine 104 drives the downstream expansion turbine 140, downstream of which the gas flow passes through an exchanger linked to the heat recovery unit 106; in a variant, this exchanger can supply the low-pressure compressor 101 in a closed circuit. The upstream expansion turbine 130 and the downstream expansion turbine 140 are thus associated with a single electrical machine 120, which is now the only one included in the turbogenerator 100.

[0048] The first low-pressure turbocharger 151 (low-pressure spool) is sized so that the power of the low-pressure turbine 104 is equal to the power of the low-pressure compressor 101. The excess power (remaining unrecovered) will be recovered on the downstream expansion turbine 140. Similarly, we will propose a high pressure spool comprising the high pressure compressor 102 and the high pressure turbine 103. The power of the high pressure turbine 103 is equal to the power of the high pressure compressor 102. The excess power will be recovered by the upstream expansion turbine 130.

[0049] Thus a third spool comprises the single electrical machine 120, the upstream expansion turbine 130, and the downstream expansion turbine 140.

[0050] By doing so, it is possible to propose a cycle with a single electrical machine, a single power electronics and a single inverter.

[0051] This circuit certainly includes two additional expansion turbines, the upstream expansion turbine 130, and the downstream expansion turbine 140, but the cost of each turbine is low compared to that of the power electronics, which makes it possible to reduce the cost price of the system.

[0052] The power recovery at the output of the high pressure stage 152 is advantageous. Thermodynamically, the system according to the invention thus makes it possible to operate at the point of maximum efficiency or the point of maximum specific net work.

[0053] We thus propose an IRReGT cycle with a single electric machine while keeping separate spools. To do this, we advantageously use two turbochargers without an electric machine. Thus this first characteristic of the invention allows the saving of an electric machine.

[0054] The proposed innovation can be applied to a turbo-generator type energy converter with a thermodynamic cycle comprising a double stage, of the intercooled recuperative reheat gas turbine (IRReGT) type or any other thermodynamic cycle comprising more compression and expansion stages. The innovation mainly concerns the aspect of using a single electrical machine coupled to the turbines. This allows savings in cost and complexity.

[0055] A variant, visible in [Fig.6], concerns a turbogenerator 100 which constitutes a triple-stage machine with the same principle. This turbogenerator 100 comprises a third very high pressure stage with a very high pressure compressor 202 driven by a very high pressure turbine 203, via a very high pressure shaft 212. A second exchanger 205 is interposed between the high pressure compressor 102 and the very high pressure compressor 202. An additional combustion chamber 160 is interposed between the downstream expansion turbine 140 and the low pressure turbine 104. An additional turbine 150 is coupled to the downstream expansion turbine 140, it is powered by the low pressure turbine 104, and its gas flow which reaches the exchanger coupled with the recuperator 106. The only electrical machine remains the single electrical machine 120.

[0056] The technical advantages of the invention are numerous: reduction of the cost of the system (a single electrical machine, a single inverter, a single electronics power), possibility of positioning the power production component in different places of a vehicle within the available functional volume, reduction of the dimensions of the components, closing of the circuit

[0057] The invention provides in particular an interesting advantage in terms of occupied volume, because it is possible to integrate the turbogenerator in place of the battery pack without impacting the architecture of the vehicle.

[0058] The principle of the invention can be used for different types of turbomachines or compression and expansion machines. In particular for compressor / turbine technologies of the following types: Scroll, gear, screw, radial turbomachines, axial turbomachines, pistons.

[0059] Using a single electrical machine reduces the total cost of the turbogenerator system by reducing the cost of the inverter, power electronics and the electrical machine. This also provides a positive environmental impact, due to the lower use of resources / materials.

[0060] Such a turbogenerator-based converter is a low-cost solution for hybridizing the battery of an electric or hybrid motor vehicle, offering long autonomy with a bio-fuel with low environmental impact.

[0061] This solution allows the advantages of electric vehicles to be retained: driving pleasure, very low maintenance, low noise level, while increasing autonomy and reducing cost.

[0062] In short, the invention presents an economic technical interest. Indeed, it makes it possible to propose a low-cost converter which can be easily integrated into an electric vehicle to hybridize its battery and propose a vehicle with high autonomy and low cost.

Claims

Claims

1. Electricity production device comprising at least one IRReGT cycle turbogenerator (100) with recovery and intermediate cooling and intermediate reheating, said turbogenerator (100) being a double-stage turbomachine with recovery and intermediate cooling, with a low pressure stage (151) and a high pressure stage (152) separated, said turbogenerator (100) comprising a low pressure compressor (101) linked to a low pressure turbine (104) by a low pressure shaft (111), a high pressure compressor (102) linked to a high pressure turbine (103) by a high pressure shaft (112), at least one first cooling exchanger (105) arranged to cool the gas flow between said low pressure compressor (101) and said high pressure compressor (102),a heat recovery unit (106) between said high pressure compressor (102) and a high pressure combustion chamber (107) arranged to drive said high pressure turbine (103) which feeds a low pressure combustion chamber (108) driving said low pressure turbine (104), characterized in that said turbogenerator (100) comprises a single electrical machine (120) driven by at least one additional turbine (130; 140) driven by a gas flow from said low pressure turbine (104) or by a gas flow from said high pressure turbine (103).,

2. Electricity production device according to claim 1 characterized in that said turbogenerator (100) comprises a single electrical machine (120) driven by an upstream expansion turbine (130) driven by a gas flow from said high pressure turbine (103), and by a downstream expansion turbine (140) driven by a gas flow from said low pressure turbine (104).

3. Electricity production device according to claim 2 characterized in that the power of the low pressure turbine (104) is equal to the power of said low pressure compressor (101), the excess power being recovered on said downstream expansion turbine (140), and in that the power of said high pressure turbine (103) is equal to the power of said high pressure compressor (102), the excess power being recovered on said upstream expansion turbine (130).

4. Electricity production device according to claims 2 and 3 characterized in that said turbogenerator (100) comprises a third very high pressure stage with a very high pressure compressor.

5.

6. (202) driven by a very high pressure turbine (203) via a very high pressure shaft (212), a second exchanger (205) between said high pressure compressor (102) and said very high pressure compressor (202), an additional combustion chamber (160) between said downstream expansion turbine (140) and said low pressure turbine (104), and an additional turbine (150) coupled to said downstream expansion turbine (140) and powered by said low pressure turbine (104). Electric or hybrid motor vehicle (5000) comprising at least one electricity production device according to one of claims 1 to 4. Stationary system (1000) comprising at least one electricity production device according to one of claims 1 to 4.

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