Turbogenerator device with fuel evaporation combined with a recuperator exchanger
By integrating fuel injection into the recuperative exchanger, the turbogenerator device addresses fuel flexibility and efficiency challenges, enabling operation with diverse fuels and reducing costs without a separate evaporator.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- STELLANTIS AUTO SAS
- Filing Date
- 2025-10-15
- Publication Date
- 2026-05-15
AI Technical Summary
Existing turbogenerator devices face challenges in efficiently operating with a variety of fuels, particularly biofuels, due to the need for separate fuel evaporators, which increases cost and limits fuel flexibility.
The turbogenerator device integrates fuel injection into the recuperative exchanger, where fuel mixes with compressed air and is heated/vaporized, eliminating the need for a separate evaporator and allowing broader fuel compatibility, including biofuels.
This configuration enhances combustion efficiency, reduces costs, and expands the range of usable fuels, while maintaining high thermodynamic efficiency and compact design.
Smart Images
Figure FR2025000199_15052026_PF_FP_ABST
Abstract
Description
[0001] DESCRIPTION
[0002] TITLE OF THE INVENTION: TURBOGENERATOR DEVICE WITH FUEL EVAPORATION COMBINED WITH A RECOVERY HEAT EXCHANGER
[0003] The present invention claims priority from the French application
[0004] No. 2412068 filed on 05.11.2024, the content of which (text, drawings and claims) is incorporated herein by reference
[0005]
[0001] This disclosure generally relates to the field of gas turbine cycle type turbogenerator devices, otherwise known as "turbomachines." Here, we are in the context of a motor vehicle, where the turbomachine is involved in a range extender system for an electric or hybrid vehicle.
[0006]
[0002] The present invention relates more specifically to the ability of such turbogenerator devices to be able to operate with a variety of possible fuels, e.g. biofuels, ethanols, diesel, fuel oils, more generally compositions of molecules with various hydrocarbon chains or alcohols.
[0007]
[0003] The present invention also relates to the optimization of efficiency and the optimization of heat exchange involved in the architectures of such turbogenerator devices. In practice, it is common to use a heat recovery exchanger that recovers heat from the exhaust gases and transfers it to fresh air to preheat it before it enters the combustion chamber.
[0008]
[0004] Of course, we also seek to obtain such turbogenerator devices at the lowest possible cost price.
[0009]
[0005] In such turbogenerator devices, one or more catalytic combustion chambers are used, and it is preferable that the fuel entering the combustion chamber be vaporized to improve the overall efficiency of the loop. In known solutions, a fuel evaporator is installed on the fuel supply circuit upstream of the combustion chamber.
[0006] The turbomachine system proposed here, also called a turbogenerator device, may have two compression stages or a single compression stage, as will be seen later.
[0010]
[0007] It is in the context described above that the present inventors sought to optimize the architecture of the system, with the simultaneous objective of being able to use a wide variety of fuel types.
[0011]
[0008] To this end, the invention proposes a turbogenerator device, comprising a first stage which includes a first compressor and a first turbine linked together via a first shaft, a first combustion chamber delivering a first gas flow to the first turbine, a recuperative exchanger comprising a first path with a first inlet receiving compressed air from the first compressor and a first outlet directed towards the first combustion chamber, the recuperative exchanger receiving burnt gases on a second inlet and releasing said cooled burnt gases via a second outlet, characterized in that the device provides for fuel injection, via an auxiliary inlet into the recuperative exchanger where the fuel mixes with the compressed air, the fuel being heated and / or vaporized during its path to the first outlet,so that the fuel arrives in a vaporized state in the first combustion chamber.
[0012]
[0009] Wherefore, combustion is efficiently achieved in contact with the catalytic bread.
[0013]
[0010] Using part of the recuperator circuit to perform the fuel evaporation function avoids having to install a specific evaporator as is necessary in known designs.
[0014]
[0011] The cost price of the turbomachine system is thus optimized.
[0015]
[0012] It is noted that the fuel mixes with the compressed fresh air before entering the first combustion chamber at an intermediate point in the compressed air path, between the first inlet and the first outlet. In other words, the compressed fresh air circulates alone in the first portion of its path through the heat exchanger, and the fuel is added to it for the remainder, namely for the second portion of its path through the heat exchanger.
[0013] Thanks to these arrangements, the range of fuels that can be used in such a turbomachine is also broadened. In particular, the turbomachine can operate with a wide range of fuels of biological origin, in other words, biofuels.
[0016]
[0014] It is noted that the fuel can be a hydrocarbon fuel CxH y or a fuel from the alcohol family such as ethanol or methanol or a mixture of the aforementioned components.
[0017]
[0015] It should be noted that the heat exchanger extracts heat from the turbine outlet flow and transfers it to the air flow exiting the compressor and to the first combustion chamber.
[0018]
[0016] It should be noted that the recuperating exchanger can also be called 'regenerator' or simply 'recuperator'.
[0019]
[0017] It is noted that the pressure in the path of the compressed air is on the order of 7 bar to 9 bar.
[0020]
[0018] According to an advantageous option, a heating element can be provided in the first combustion chamber so that during a cold start, a target temperature in the first combustion chamber is reached quickly.
[0021]
[0019] Next, the heat exchanger takes over to heat the air and fuel, and the heating element becomes inactive. In practice, the heating element is only activated for a few seconds or at most a few tens of seconds.
[0022]
[0020] According to one embodiment, the fuel injection is carried out at an intermediate position on the first path between the first inlet and the first outlet, preferably between 40% and 60% of the first path.
[0023]
[0021] The point of entry for fuel injection can be chosen according to the different fuels that will be usable by the turbomachine loop.
[0024]
[0022] According to one embodiment, the recuperating exchanger comprises groups of tubes conveying the compressed air, each group of tubes being connected to the next by means of a plenum, the fuel injection being carried out via one end of a group of tubes or into a plenum.
[0025]
[0023] The fuel can be injected directly into a group of tubes, that is to say, in practice, into a subset of the tubes of a group of tubes. Alternatively, the fuel can be injected into a collector plenum connecting two successive groups of tubes.
[0026]
[0024] According to another aspect (two-stage configuration), the turbogenerator device may further comprise a second stage which includes a second compressor and a second turbine linked together via a second shaft, a second combustion chamber receiving the gases from the first turbine and delivering at the outlet a flow of gas to the second turbine, the second stage forming a low-pressure stage and the first stage forming a high-pressure stage, the second compressor delivering compressed air to the first compressor.
[0027]
[0025] The use of two stages makes it possible to achieve a higher thermodynamic efficiency than in the single-stage configuration.
[0028]
[0026] According to one embodiment, the turbogenerator device may further include an intercooler exchanger arranged between the second compressor and the first compressor, and the fuel then passes through the intercooler exchanger before being introduced into the recuperator exchanger.
[0029]
[0027] Passing through the intercooler exchanger allows calories to be delivered into the fuel to be injected and to cause it to undergo an initial temperature increase.
[0030]
[0028] According to one embodiment, a heating element may be provided in the second combustion chamber so that during a cold start, a target temperature in the second combustion chamber is reached quickly.
[0031]
[0029] It is noted that for the cold start of a two-stage configuration, the second stage (low pressure) will reach cruising speed operation before the first stage (high pressure).
[0032]
[0030] According to one embodiment, the fuel passes through at least one of the electrical machines before being introduced into the recuperating exchanger.
[0033]
[0031] Passing through one or two electrical machine(s) allows calories to be delivered into the fuel to be injected and to cause it to undergo a temperature increase before it arrives in the recuperating exchanger.
[0034]
[0032] According to one embodiment, the fuel passes through at least one auxiliary heat exchanger before being introduced into the heat recovery heat exchanger. This auxiliary heat exchanger allows heat to be recovered from the flue gases before the flue gases enter the heat recovery heat exchanger.
[0035]
[0033] Passing through this auxiliary exchanger allows calories to be delivered into the fuel to be injected and to cause it to undergo a temperature increase before it passes into the recuperative exchanger.
[0036]
[0034] It is noted that the pressure in the compressed air circuit between the first compressor and the first combustion chamber is in the order of 7 bar to 9 bar.
[0037]
[0035] According to another aspect, the present invention also relates to a motor vehicle comprising a turbogenerator device as defined above. 036 The invention will be further detailed by describing non-limiting embodiments, and based on the accompanying figures illustrating variants of the invention, in which:
[0038] [Fig.1] schematically illustrates an example of a powertrain of an electric vehicle equipped with a range extender, or in other words a series type hybrid powertrain, without direct interaction between the turbomachine and the wheel shafts;
[0039] [Fig.2] schematically illustrates a turbomachine system, otherwise called here a turbogenerator device, for a motor vehicle, in a single-stage compression version, with fuel injection into the recuperator exchanger according to the present invention;
[0040] [Fig.3] schematically illustrates a turbomachine system for motor vehicles, in a two-stage compression version, with fuel injection into the recuperating exchanger according to the present invention;
[0041] [Fig.4] schematically illustrates an example of a heat exchanger, seen in perspective;
[0042] [Fig.5] schematically illustrates an example of a heat exchanger, in front view in cross-section, with only about fifteen tubes represented per heat exchange zone, the others not being shown;
[0043] [Fig.6] schematically illustrates the example of the heat exchanger in Figure 5, in top view and in section, with only a few tubes represented per heat exchange zone; [Fig.7] schematically illustrates the path of the compressed air in an example of a heat exchanger;
[0044] [Fig.8] is analogous to figure 3 and schematically illustrates variant elements according to the present invention.
[0045] [0371 In the various figures, the same references designate identical or similar elements. For reasons of clarity, some elements are not necessarily shown to scale.
[0046]
[0038] Gas turbine-type power converters are considered as potential range extender solutions for electric or hybrid vehicles. These converters are also more simply called "turbomachines." 039 This type of converter can operate in APU (Auxiliary Power Unit) mode, where its role is to recharge the batteries of an electric vehicle. It is thus mechanically decoupled from the powertrain and operates at its maximum efficiency point.
[0047]
[0040] The gas turbine cycle with cooler, recuperator and reheater is a cycle with high potential for automotive applications. This cycle makes it possible to achieve high efficiency but also high power density (high specific net work).
[0048]
[0041] This technology offers the following advantages: low emissions, low noise emissions, and the ability to operate with several types of fuel. These turbogenerators also have a compact design.
[0049]
[0042] The turbomachine system proposed here, otherwise called a turbogenerator device, may comprise two compression stages or a single compression stage.
[0050] [0431 A series hybrid drive system is illustrated in Figure 1, with a traction battery 26 that supplies electrical power to a power control unit 27, which is responsible for driving the windings of the electric traction machine 28, and which drives the wheels 29 of the vehicle. This being known, a further description is not given here.
[0044] The turbogenerator device is used to recharge the traction battery 26. At least one RC fuel tank is provided on board the vehicle to supply fuel to the turbogenerator device.
[0051]
[0045] It is noted that it is not excluded that the vehicle may be equipped with two or more tanks, each tank being capable of containing a particular type of fuel, in order to increase the refueling flexibility and the range of the vehicle.
[0052]
[0046] Figure 2 shows a turbomachine system 8 according to the present invention, with a single stage for this first embodiment.
[0053]
[0047] The system includes a first stage ET1 which includes a first compressor CP1 and a first turbine TB1 linked together in rotation by means of a first shaft A1.
[0054]
[0048] The system includes a first electric machine MG1 connected to the first shaft, i.e. fixed in rotation with the first shaft A1.
[0055]
[0049] The system includes a first combustion chamber CC1 delivering a first gas flow F1 to the first turbine TB1 via a hot conduit 5.
[0056]
[0050] The system includes a recuperative heat exchanger 1 interposed between the outlet of the first compressor CP1 and the inlet of the first combustion chamber CC1. The recuperative heat exchanger 1 comprises a rising portion 61 and a falling portion 62. In the rising portion 61, the temperature increases. In the falling portion 62, the temperature decreases.
[0057]
[0051] In other words, the heat exchanger 1 allows the compressed intake air to be heated by heat exchange with the hot exhaust gases exiting the combustion chamber.
[052] This heat exchanger improves the overall efficiency of the turbomachine, in the case of a two-stage turbomachine, and also in the case of a single-stage turbomachine.
[0058]
[0053] The system includes a first supply line 3 for compressed air from the first compressor CP1, to an inlet of the first combustion chamber CC1, passing through the rising part 61 of the recuperator exchanger.
[0059]
[0054] More specifically, the recuperating exchanger 1 includes for compressed air a first internal path (rising part 61) with on the one hand a first inlet E1 receiving air via a portion of pipe 31 of the supply pipe 3, and on the other hand a first outlet S1 directed towards the first combustion chamber CC1 via a portion of pipe 32.
[0060]
[0055] The conduit 18 directs the output of the first turbine TB1 towards the downflow section of the recuperator 62. In the downflow section of the recuperator 62, the recuperator exchanger 1 receives burnt gases (flow F2) on a second inlet E2 and releases said cooled burnt gases on a second outlet S2.
[0061]
[0056] The first combustion chamber CC1 is supplied with a fuel. The fuel in question may be a hydrocarbon, octane or other carbon chain, or perhaps, for example, methanol or ethanol.
[0062]
[0057] Advantageously according to the present invention, the fuel is injected via an auxiliary inlet EF into the recuperating exchanger.
[0063]
[0058] On the path from the auxiliary inlet EF to the first outlet S1, the fuel mixes with compressed air, and the fuel-air mixture is heated and vaporized. Thus, the fuel arrives in a vaporized state in the first combustion chamber CC1.
[0064]
[0059] As a reminder, a fuel is a chemical compound which, with an oxidizer (such as dioxygen), burns in a chemical reaction generating heat. This rapid exothermic oxidation reaction is promoted by contact with the catalytic block placed in the combustion chamber.
[0065]
[0060] The fuels used may be biofuels, ethanols, diesel, fuel oils, more generally compositions of molecules with various hydrocarbon chains or alcohols.
[0066]
[0061] The air temperature is T3 at the compressor outlet and at the inlet of the recuperator 1. The air temperature is T4 at the outlet of the recuperator 1. T4 is substantially higher than T3, typically by an additional value between 100°C and 300°C.
[0062] At the outlet of the combustion chamber CC1, the flue gases have a temperature T5. T5 is typically between 800°C and 950°C. At the outlet of the first turbine TB1, the flue gases have a temperature T6, slightly lower than T5.
[0067] [0631 The pressure P1 is the pressure prevailing in the first supply line. In a typical embodiment, P1 is between 7 bar and 9 bar.
[0068]
[0064] The target temperature T4 at the inlet of the first combustion chamber CC1 is at least 500°C, preferably at least 600°C.
[0069]
[0065] A desired heating of the compressed air towards this target temperature can be dimensioned with the contribution of the recuperative exchanger which arrives at a temperature close to the outlet of the combustion chamber, i.e. at least 800° C.
[0070] [0661 In addition, a heating resistance RC1 is provided in the first combustion chamber CC1 so that during a cold start, a target temperature in the first combustion chamber is reached quickly, typically in a few seconds or tens of seconds.
[0071]
[0067] Figure 3 shows a system diagram of a turbomachine according to a second embodiment with two compression stages.
[0072] [0681 All the elements that have been commented on in relation to the first embodiment are assumed to be identical or similar and are not described again here.
[0073] [0691 A first stage ET1, here called high pressure, is similar to what has been described previously; it includes a high pressure compressor CP1 ('first' compressor) and a high pressure turbine TB1 ('first' turbine), these two entities being linked together via the first shaft A1, the first shaft being linked to the first electric machine MG1.
[0074] [0701 A second stage ET2, referred to as a low-pressure stage, comprises a low-pressure compressor CP2 ('second' compressor) and a low-pressure turbine TB2 ('second' turbine), these two entities being linked together by means of a second shaft A2. This second shaft A2 drives a second electrical machine MG2, which is used primarily as a generator and secondarily as a motor for the startup phase of the second stage.
[0071] The second stage ET2 includes a second combustion chamber CC2. In the two-stage configuration, the outlet of the first turbine is directed to the second combustion chamber CC2.
[0075]
[0072] The second combustion chamber CC2 delivers a gas flow to the second turbine TB2 at temperature T7. The outlet of the second turbine TB2 delivers a flow F8 which is directed to the descending part of the recuperator exchanger 1 via the pipe 18.
[0076]
[0073] In addition, an AF air filter is arranged upstream of the low pressure compressor CP2. The air filter admits fresh air at temperature T1.
[0077]
[0074] In addition, a cooling exchanger IC ('intercooler') cools the air taken from the outlet of the low pressure compressor and brought to the inlet of the high pressure compressor CP1.
[0078]
[0075] The heat recovery exchanger takes heat from the outlet flow F8 of the second turbine TB2 and transfers it to the outlet flow of the first compressor CP1.
[0079]
[0076] Furthermore, a heating element RC2 is provided in the second combustion chamber CC2 so that, during a cold start, a target temperature in the second combustion chamber is reached quickly. It should be noted that in the two-stage configuration, the presence of the first heating element RC1 is not necessarily required.
[0080]
[0077] Regarding the heating element or heating elements, as soon as the heat exchanger is close to its nominal cruising temperature, a control unit of the turbomachine interrupts the electrical supply to the heating elements.
[0081]
[0078] The average electrical consumption of the resistors is therefore low. The weight of the electrical resistors is also insignificant.
[0082]
[0079] As can be seen in figures 4 to 6, the regenerative exchanger 1 (the heat exchanger) includes a shell 6 delimiting an internal volume denoted E0.
[0083]
[0080] A coordinate system XYZ is defined for the heat exchanger. The X direction corresponds to the longitudinal direction of the vehicle. The Y direction corresponds to the transverse direction of the vehicle. The Z direction can be substantially vertical.
[0081] In the example presented, the heat exchanger 1 is the largest component of the turbomachinery system. The heat exchanger 1 has a generally parallelepiped shape, which facilitates good integration into the vehicle's architecture, particularly in the lower portion of the chassis. The longest dimension LY extends along the transverse direction Y. In one example, the length LY extends across almost the entire width of the vehicle, for example, at least 100 cm. The dimensions LX and LZ can typically be between 10 cm and 20 cm.
[0084]
[0082] The envelope 6 comprises a front wall 10, a back wall 15, a bottom wall 13, a top wall 11, a left side wall 12 and a right side wall 14. These walls delimit the internal volume E0, in a hermetically sealed manner, except for the fluid inlets and outlets provided for this purpose.
[0085]
[0083] Arranged on the front wall 10 of the heat exchanger 1 are: the inlet of the first fluid E1, the outlet of the first fluid S1, and the inlet of the second fluid E2.
[0086]
[0084] The outlet of the second fluid S2 is located on one or both side walls. Curved return outlets may be provided on the sides of the front face, so that all fluid inlets and outlets are located on the same side of the heat exchanger 1, for optimal integration into the vehicle architecture.
[0087]
[0085] Inside the exchanger, there is provided a first heat exchange zone Z1, a second heat exchange zone Z2, a third heat exchange zone Z3 and a fourth heat exchange zone Z4.
[0088]
[0086] The order of the heat exchange zones follows the path of the first fluid F2, namely the compressed air which exits the compressor CP1 and is directed towards the first CC1.
[087] By contrast, the path of the second fluid (hot gases) passes first through the fourth heat exchange zone Z4, then the third heat exchange zone Z3, then the second heat exchange zone Z2 and finally the first heat exchange zone Z1.
[0089]
[0088] Therefore, the heat exchanger considered here is a so-called counter-current or cross-flow exchanger.
[0089] The path of the first fluid F1 zigzags as illustrated by the dashed-line arrow path W1 shown in Figure 4.
[0090]
[0090] Inside the heat exchange zones, the first fluid circulates in tubes 2. Here the tubes 2 are of round cross-section but they could have another cross-sectional shape.
[0091]
[0091] The tubes 2 are arranged parallel to each other. The axes of the tubes are parallel to the longitudinal direction X.
[0092]
[0092] More specifically, the heat exchanger 1 comprises a plurality of tubes, the first internal circulation space EE1 is defined which comprises the internal area of the plurality of tubes 2.
[0093]
[0093] The number of tubes can range from 1000 tubes to 3000 tubes.
[0094]
[0094] The tubes 2 are formed from copper, aluminum or alloy resistant to temperatures of 800° C.
[0095]
[0095] The inner diameter of the tubes 2 is between 1 millimeter and 3 millimeters.
[0096]
[0096] According to the illustrated example, we have here four cascaded stages for the path of fluid F1. Of course, the number of cascaded stages could be different: less than four or even more than four.
[0097]
[0097] A first group of tubes GT1 is arranged in the first heat exchange zone Z1. A second group of tubes GT2 is arranged in the second heat exchange zone Z2. A third group of tubes GT3 is arranged in the third heat exchange zone Z3. A fourth group of tubes GT4 is arranged in the fourth heat exchange zone Z4.
[0098]
[0098] Partitions are provided which delimit the distinct heat exchange zones.
[0099]
[0099] A first partition 51 comprises four faces (as seen in Fig. 3) and delimits the fourth heat exchange zone Z4. A second partition 52 also comprises four faces and delimits the third heat exchange zone Z3, together with the first partition 51. A third partition 53 also comprises four faces and delimits the second heat exchange zone Z2 with the second partition 52.
[0100] In these partitions are arranged 9 lights which allow the second fluid F2 to flow from one heat exchange zone to the next (from Z4 to Z3, from Z3 to Z2 and from Z2 to Z1).
[0100]
[0101] The internal volume 6 includes a first internal circulation space denoted EE1 configured to convey the first fluid F1, and a second internal circulation space denoted EE2 configured to convey the second fluid F2.
[0101]
[0102] The first fluid F1 is provided with a first inlet port E1, an upstream collector zone 42 serving all or part of the plurality of tubes, a downstream collector zone 41, and a first outlet port S1.
[0102] [1031 In addition, an EF inlet for fuel is planned.
[0103]
[0104] In the illustrated example, particularly in relation to figures 6 and 7, the fuel is injected into the third heat exchange zone Z3. In practice, the fuel is injected into certain tubes of the third group of tubes GT3.
[0104]
[0105] To do this, some tubes are in communication with a front injection plate marked 95 and visible in figures 4 and 5. The front injection plate is accessible from the front face 10. The fuel is injected with a pressure close to or slightly higher than the pressure that prevails in the path of the first fluid namely P1.
[0105]
[0006] It is noted that the fuel is injected approximately halfway through the path of the compressed air in the recuperator
[0106]
[0107] The fuel mixes with the fresh compressed air before entering the first combustion chamber at an intermediate point in the compressed air path, between the first inlet and the first outlet. In other words, the fresh compressed air circulates alone in the first part of its path through the heat exchanger, and the fuel is added for the remainder, namely for the second part of its path through the heat exchanger.
[0107]
[0108] According to a non-limiting example, fuel injection is carried out at an intermediate position on the first path between the first inlet E1 and the first outlet S1, at a position between 40% and 60% of the first path.
[0108]
[0109] It should be noted that the fuel could be injected at the location of another group of tubes.
[0010] According to our example, the fuel can be injected into one of the plenums that connects two successive groups of tubes; for example, an injection into plenum D34, which is located downstream of the third group of tubes and upstream of the fourth group of tubes, is shown in dashed lines in Figure 7.
[0109] [111l On the path W1 of the first fluid F1, between the upstream collector zone and the downstream collector zone, one or more distribution spaces (also called 'plenums') can be found at the ends of the tubes, as in the example illustrated in the figures. These distribution spaces allow the first fluid to be directed from the inside of one subset of tubes to the inside of another subset of tubes. The distribution spaces act as plenums that collect the output of one group of tubes and distribute the first fluid to another group of tubes.
[0110]
[0112] A first distribution space, also called for short 'plenum', denoted D34, connects the tubes of the fourth heat exchange zone Z4 with the tubes of the third heat exchange zone Z3. A second distribution space D23 connects the tubes of the third heat exchange zone Z3 with the tubes of the second heat exchange zone Z2.
[0111]
[0113] A third distribution space D12 connects the tubes of the second heat exchange zone Z2 with the tubes of the first heat exchange zone Z1.
[0112]
[0114] In the illustrated architecture for the changer exchanger, a front perforated plate 71 and a rear perforated plate 72 are provided.
[0113]
[0115] The front and rear perforated plates support and hold the tubes 2 and act as a sealed separation between the heat exchange zones and the distribution spaces.
[116] It is noted that the second fluid does not circulate in the distribution spaces; the second fluid F2 circulates only in the heat exchange zones and passes from one to the other through the openings 9.
[0114]
[0117] The second internal circulation space, denoted EE2, comprises the outer zone of the plurality of tubes, for their part located in the heat exchange zones Z1 to Z4.
[0118] According to an example of a turbomachine for a range extender application, the inlet of the first fluid occurs at a temperature between 100°C and 200°C, the outlet of the first fluid F1 occurs, after heating by the second fluid F2, at a temperature between 600°C and 700°C.
[0115]
[0119] According to this same example, the entry of the second fluid occurs at a temperature between 750°C and 820°C, the exit of the second fluid occurs at a temperature between 200°C and 300°C.
[0116]
[0120] It is noted that the flows are generally perpendicular, more precisely in each heat exchange zone, the path W1 of the first fluid F1 and substantially perpendicular to the path W2 of the second fluid F2.
[0117]
[0121] Figure 7 shows the diagram of the path of the compressed air in the recuperating exchanger and the addition of the fuel between the first inlet E1 and the first outlet S1.
[0118]
[0122] The first fluid F1 enters through inlet E1 and reaches the upstream manifold zone 42 serving the first group of tubes GT1. The first fluid exiting the tubes of GT1 enters the plenum D12 serving the second group of tubes GT2. The first fluid F1 exiting the tubes of GT2 enters the plenum D23 serving the third group of tubes GT3. The first fluid exiting the tubes of GT3 enters the plenum D34 serving the third group of tubes GT4.
[0119]
[0123] The first fluid exiting the GT4 tubes between the downstream collector zone 41, and exits through outlet S1.
[0120]
[0124] It is noted that the fuel inlet has been represented on the third group of tubes but that according to variants, the fuel inlet EF' could be located on another group of tubes or on one of the plenums D12,D23 for example.
[0121]
[0005] Figure 8 shows some other variants that can be implemented within the framework of the present invention.
[0122]
[0126] For example, it is possible to have an additional injection of fuel into the second combustion chamber CC2 by means of an auxiliary inlet marked EF2.
[0127] According to an optional feature, the fuel may have a preliminary heating path before entering the heat recovery exchanger; for example, the fuel may pass through the cooling exchanger, i.e. the so-called intercooler IC, in order to recover heat.
[0123]
[0128] According to another feature, the fuel can pass through certain elements of the first electrical machine MG1, for example, through thermal contact with the inverter's power switches, which are large heat sinks, or even through thermal contact at certain bearings of the machine. This can also be applied mutatis mutandis to the second electrical machine MG2.
[0124]
[0129] According to another feature, the fuel can pass through an auxiliary exchanger 4 before being introduced into the recuperator exchanger. This auxiliary exchanger 4 allows heat present in the combustion gases to be transferred into the fuel before the combustion gases enter the recuperator exchanger 1.
[0125]
[0130] Of course, the optional features shown in Figure 8 can be used separately or in combination with each other.
[0126]
[0131] It can be seen that in the illustrated two-stage turbomachine, the low-pressure stage can be started a few seconds before the high-pressure stage. The fluid exiting the low-pressure compressor is already hot and heats the first fluid via the heat exchanger, so that the start-up of the high-pressure stage is already closer to nominal operating conditions.
Claims
DEMANDS 1. Turbogenerator device (8), comprising a first stage (ET1) which includes a first compressor (CP1) and a first turbine (TB1) linked together via a first shaft (A1), a first combustion chamber (CC1) delivering a first gas flow (F1) to the first turbine, a recuperator exchanger (1) comprising a first path with a first inlet (E1) receiving compressed air from the first compressor and a first outlet (S1) directed to the first combustion chamber (CC1), the recuperator exchanger (1) receiving burnt gases on a second inlet (E2) and releasing said cooled burnt gases via a second outlet (S2), characterized in that the device provides for fuel injection, via an auxiliary inlet (EF) into the recuperator exchanger where the fuel mixes with the compressed air, the fuel being heated and / or vaporized during its path to the first outlet (S1),so that the fuel arrives in a vaporized state in the first combustion chamber.
2. Turbogenerator device according to claim 1, characterized in that a heating resistance (RC1) is provided in the first combustion chamber (CC1) so that during a cold start, a target temperature in the first combustion chamber is reached quickly.
3. Turbogenerator device according to any one of claims 1 to 2, wherein the fuel injection is carried out at an intermediate position (EF) on the first path between the first inlet (E1) and the first outlet (S1), preferably between 40% and 60% of the first path.
4. Turbogenerator device according to any one of claims 1 to 2, wherein the recuperating exchanger comprises groups of tubes (GT1, GT2, GT3) conveying the compressed air, each group of tubes being connected to the next by means of a plenum, the fuel injection being carried out at one end of a group of tubes or into a plenum.
5. Turbogenerator device according to any one of claims 1 to 4, further comprising a second stage (ET2) which includes a second compressor (CP2) and a second turbine (TB2) linked together via a second shaft (A2), a second combustion chamber (CC2) receiving the gases from the first turbine (TB1) and delivering at the outlet a flow of gas to the second turbine (TB2), the second stage (ET2) forming a low pressure stage and the first stage (ET1) forming a high pressure stage, the second compressor (CP2) delivering compressed air to the first compressor (CP1).
6. Turbogenerator device according to claim 5, further comprising an intercooler exchanger (IC) arranged between the second compressor (CP2) and the first compressor (CP1), and characterized in that the fuel then passes through the intercooler exchanger before being introduced into the recuperator exchanger (1).
7. Turbogenerator device according to any one of claims 5 to 6, characterized in that a heating resistance (RC2) is provided in the second combustion chamber (CC2) so that during a cold start, a target temperature in the second combustion chamber is reached rapidly.
8. Turbogenerator device according to any one of claims 1 to 7, characterized in that the fuel passes through at least one of the electrical machines (MG1, MG2) before being introduced into the recuperator exchanger (1).
9. Turbogenerator device according to any one of claims 1 to 8, characterized in that the fuel passes through at least one auxiliary exchanger (4) before being introduced into the recuperator exchanger (1).
10. Motor vehicle comprising a turbogenerator device according to any one of claims 1 to 9.