EP4352346A1

EP4352346A1 - Turbocharger

Info

Publication number: EP4352346A1
Application number: EP22735364.6A
Authority: EP
Inventors: Robert Szolak; Paul BEUTEL; Bernd Danckert
Original assignee: Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Current assignee: Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Priority date: 2021-06-11
Filing date: 2022-06-10
Publication date: 2024-04-17
Also published as: DE102021205972A1; US20240110498A1; CN117480313A; KR20240017833A; WO2022258801A1; JP2024523235A

Abstract

The invention relates to a turbocharger (1) with a compressor arrangement (2) which is configured to compress the fresh air of an internal combustion engine, comprising at least one compressor housing (20) with a fresh air inlet (201) and a fresh air outlet (202), wherein at least one compressor impeller (32) is arranged in the compressor housing (20), and with at least one exhaust gas turbine (3) for driving the compressor arrangement (2), with at least one turbine housing (30) with an exhaust gas inlet (301) and an exhaust gas outlet (302), wherein at least one turbine wheel (32) is arranged in the turbine housing (30), and, furthermore, with a heated catalytic converter (4) which is configured to at least partially convert supplied fuel with fresh air and/or exhaust gas, wherein the heated catalytic converter (4) comprises a catalytic converter housing (40) with a gas inlet (401) and a gas outlet (402) and a fuel inlet (403), wherein firstly the catalytic converter housing (40) and secondly the compressor housing (20) and/or the turbine housing (30) are in thermal contact on at least one part surface.

Description

turbocharger

The invention relates to a turbocharger with a compressor arrangement, which is set up for compressing the fresh air of an internal combustion engine, containing at least one compressor housing with a fresh air inlet and a fresh air outlet, with at least one compressor wheel being arranged in the compressor housing, and with at least one exhaust gas turbine for driving the Compressor arrangement, having at least one turbine housing with an exhaust gas inlet and an exhaust gas outlet, wherein at least one turbine wheel is arranged in the turbine housing.

It is known from practice to equip an internal combustion engine with at least one turbocharger. The turbocharger contains a turbine, which takes kinetic energy from the exhaust gas flow and makes it available as mechanical power. This mechanical power is used to drive a compressor arrangement with which the internal combustion engine can be supplied with the fresh air required for combustion at increased pressure. As a result, the response behavior, the performance and/or the consumption can be optimized.

Furthermore, it is known from practice to feed the exhaust gases of an internal combustion engine to at least one exhaust gas aftertreatment device. The exhaust aftertreatment device can contain a particle filter and/or at least one catalytic converter, for example. As a result, soot particles can be retained or pollutants such as CO, CH _x or NO _x can be oxidized or reduced and thereby rendered harmless. All known catalytic converters require an operating temperature that is higher than normal ambient conditions in order to remove pollutants from the exhaust gas to an appreciable extent. A particle filter works reliably even after a cold start. However, this must be regenerated from time to time at an elevated temperature.

A heated catalytic converter is therefore known from WO 2020/193595 A1, which is set up to convert supplied fuel with exhaust gas or fresh air. The Heizkataly capacitor can be operated in different operating states. For example, the supplied fuel can only be evaporated Lich in order to be oxidized at an exhaust aftertreatment device, whereby heat is released and the exhaust aftertreatment device heats up. In other operating states, the fuel can be at least partially converted into a synthesis gas, which has a lower light-off temperature at the exhaust gas aftertreatment device and thus enables better heating of the exhaust gas aftertreatment device in some operating states of the internal combustion engine. Finally, the fuel can be completely converted in the heated catalytic converter in order to generate a hot gas in this way, which is fed to the exhaust gas treatment device and heats it up.

This known heated catalytic converter has the disadvantage that it requires additional installation space, which can be tight, especially in passenger cars and light commercial vehicles.

Based on the prior art, the invention is therefore based on the object of specifying a device for rapid heating of an exhaust gas aftertreatment device of an internal combustion engine, which requires little installation space and is also suitable for retrofitting existing internal combustion engines. The object is achieved according to the invention by a turbocharger according to claim 1. Advantageous developments of the invention can be found in the dependent claims.

According to the invention, a turbocharger is proposed which has at least one compressor arrangement and at least one exhaust gas turbine. The compressor arrangement is intended to compress the fresh air to be supplied to an internal combustion engine. For this purpose, the compressor arrangement contains at least one compressor housing with a fresh air inlet and a fresh air outlet, with at least one compressor wheel being arranged in the compressor housing. The fresh air required for combustion of the fuel in the internal combustion engine is supplied to the compressor arrangement through the fresh air inlet at a first pressure and leaves the fresh air outlet at a second pressure, the second pressure being higher than the first pressure. The compressor arrangement thus supplies mechanical work to the fresh air.

The at least one compressor wheel can have a plurality of rotor blades and can operate as a radial compressor or axial compressor. In other embodiments of the invention, the at least one compressor wheel may be part of a screw compressor, or a Roots blower, or a swash plate compressor. The invention does not teach the use of a specific design of the Kompressoran order as a solution principle.

The at least one exhaust gas turbine is set up to drive the compressor arrangement. For this purpose, the exhaust gas turbine on the one hand and the compressor arrangement on the other hand can be driven by a rotating shaft, a gearbox, a belt drive or be connected to one another in some other manner known per se. The at least one exhaust gas turbine has at least one turbine housing with an exhaust gas inlet and an exhaust gas outlet, wherein at least one in the turbine housing Turbine wheel is arranged. The exhaust gas turbine is set up to take energy from the exhaust gas flow and to make it available as mechanical power. In this respect, an exhaust gas flow from the internal combustion engine is supplied to the turbine housing via the exhaust gas inlet at a second pressure and discharged via the exhaust gas outlet at a first pressure, the second pressure being higher than the first pressure.

The turbocharger according to the invention also has a heated catalytic converter, which is set up to at least partially convert supplied fuel with fresh air and/or exhaust gas, the heated catalytic converter containing a catalytic converter housing with at least one gas inlet and at least one gas outlet and at least one fuel inlet. Fresh air and/or exhaust gas is supplied via the gas inlet. Fuel, for example petrol or diesel, is supplied to the heated catalytic converter via the fuel inlet. In the heating catalyst, a product gas is formed from fuel and exhaust gas and/or fresh air. For this purpose, the fuel is vaporized in the heating catalyst and/or at least partially oxidized with the release of heat and/or converted into a synthesis gas via cracking reactions. The product gas thus contains a hot gas and/or fuel vapor and/or synthesis gas. The product gas leaves the heated catalyst via the gas outlet and is fed back into the exhaust gas pipe downstream of the exhaust gas turbine. The turbulence generated by the exhaust gas turbine can therefore be used to ensure that the product gas produced in the heated catalytic converter is mixed with the exhaust gas. Exhaust gas and/or fresh air can be supplied at the respective second pressure via the gas inlet and released into the exhaust gas flowing at the first pressure, so that there is a reliable flow through the catalyst housing without an additional conveying device. In some embodiments of the invention, the heated catalytic converter is set up to led to vaporize fuel without coking by means of a fleece.

According to the invention, it is now proposed that the catalytic converter housing on the one hand and the compressor housing and/or the turbine housing on the other hand be in thermal contact on at least one partial surface. On the one hand, this leads to a compact design, since the turbocharger with an integrated heated catalytic converter requires little more installation space than a known turbocharger without the additional functionality of a heated catalytic converter. In addition, internal combustion engines with a turbocharger that are already in use can easily be retrofitted with the heating device according to the invention by replacing the existing turbocharger with the turbocharger according to the invention. Additional thermal energy can thus be introduced into an exhaust gas aftertreatment device without reducing the efficiency of the internal combustion engine by internal engine measures.

Furthermore, the waste heat generated during operation of the turbocharger can be fed to the heated catalytic converter, so that the heated catalytic converter itself reaches operating temperature more quickly. As a result, the supply of electrical auxiliary energy to the heated catalytic converter can be reduced or completely avoided, so that the heated catalytic converter can be operated in a consumption-optimized manner.

In some embodiments of the invention, the turbocharger further includes a first transfer passage having a first end and an opposite second end, the first end connected to the exhaust gas inlet of the turbine housing and the second end connected to the gas inlet of the catalyst housing. This makes it possible to feed exhaust gas to the heated catalytic converter, which on the one hand introduces thermal energy into the heated catalytic converter, in order to thereby increase the conversion of the fuel on the catalytic converter enable or transport or to evaporate fuel to ver, ie to convert from the liquid to the gaseous state. In addition, the exhaust gas can be used as an oxidizing medium in order to at least partially oxidize the fuel and thereby release heat. Oxygen-rich exhaust gas is particularly suitable for this purpose, which occurs, for example, during lean operation (air ratio l>1) of a spark-ignited internal combustion engine or in self-igniting internal combustion engines in general.

In some embodiments of the invention, the turbocharger may include at least a second transfer passage having a first end and an opposite second end, the first end being connected to the fresh air outlet of the compressor housing and the second end being connected to the gas inlet of the catalyst housing. The second overflow duct thus serves to supply fresh air to the heated catalytic converter. Just like the exhaust gas, the compressed fresh air can also be used to supply additional thermal energy to the heating catalytic converter. In addition, the fresh air is suitable as an oxidizing medium for the fuel supplied to the heated catalytic converter. This ensures that the fuel is oxidized independently of the operating state of the internal combustion engine, since the oxidation can take place independently of the composition of the raw exhaust gas.

In some embodiments of the invention, the turbocharger may include a third transfer passage having a first end and an opposite second end, the first end being connected to the gas outlet of the catalyst housing and the second end being connected to the exhaust gas outlet of the turbine housing. The third overflow channel is thus suitable and intended for feeding the product gas generated in the heated catalytic converter to the exhaust pipe downstream of the exhaust gas turbine. As already described above, the product gas can be a fuel vapor or contain one. In other embodiments of the invention, the product gas can be a synthesis gas or contain a synthesis gas which is obtained by converting the fuel on the heated catalyst. In still other embodiments of the invention, the product gas can be a hot gas or contain a hot gas which is obtained by oxidizing the fuel on the heated catalytic converter. Since exhaust gas or fresh air is fed to the heated catalytic converter at a comparatively high pressure level upstream of the exhaust gas turbine and the product gas of the heated catalytic converter is fed downstream of the exhaust gas turbine at a lower pressure, the pressure drop within the exhaust gas turbine results in exhaust gas or fresh air flowing through the heated catalytic converter.

It goes without saying that the first, second or third overflow channel does not have to be present in all embodiments of the invention. In some embodiments of the invention, only one or only two of the overflow channels mentioned can be present.

In some embodiments of the invention, the first overflow duct and/or the second overflow duct and/or the third overflow duct can be designed at least in sections as a bore in the catalytic converter housing or in the compressor housing or in the turbine housing. Such a bore can be introduced either by machining or when the housing is originally formed. On the one hand, this results in simple production of the turbocharger according to the invention and mechanically robust operation, since there is no need for plastic or rubber hoses that are susceptible to wear, or for hoses to be connected to the housing.

In some embodiments of the invention, at least one nozzle can be arranged at the second end of the third overflow channel. This allows the product gas of the heating catalyst with a predetermined direction and / or to introduce a predetermined impulse into the exhaust gas flow, so that the mixing of the product gas with the exhaust gas flow is additionally promoted.

In some embodiments of the invention, a two-way valve can be present in the first overflow channel and/or in the second overflow channel and/or in the third overflow channel. Such a two-way valve can be influenced by an electrical signal from a control device, so that the flow in the respective overflow channel can be controlled or regulated. As a result, depending on the operating state, exhaust gas or fresh air or a mixture of exhaust gas and fresh air can be fed into the heated catalytic converter, or the heated catalytic converter can be completely deactivated by closing at least one overflow channel. In some embodiments of the invention, the overflow channels can be used as a wastegate valve, in that impermissibly high charging pressure is discharged into the exhaust line through the heated catalytic converter, or exhaust gas is routed past the exhaust gas turbine. An additional wastegate valve can thus be dispensed with.

In some embodiments of the invention, the turbocharger can further include a three-way valve which has three inputs/outputs to which the first overflow channel and the second overflow channel and the gas inlet are connected. The position of the three-way valve allows fresh air or exhaust gas or a mixture of fresh air and exhaust gas to be fed to the heated catalytic converter, so that the operating state of the heated catalytic converter can be set to a large extent using a single valve. By closing the three-way valve, the heated catalytic converter can be taken out of operation, for example at full load or operating conditions close to full load, which do not require any additional heating measures for the exhaust aftertreatment. In one embodiment of the invention, at least a portion of the catalyst housing and either the compressor housing or the turbine housing may be integrally formed. Such a one-piece production can be done in particular by archetypes in a casting process. In other embodiments of the invention, the housing can be manufactured at least partially in a 3D printing process. As a result, at least part of the catalytic converter housing and at least part of the compressor housing or the turbine housing can be designed as a material bond, so that heat from the compressor housing or the turbine housing can be introduced into the heated catalytic converter with little loss. In this way, rough and/or oxidized contact surfaces with a comparatively high heat transfer resistance can be avoided.

In some embodiments of the invention, at least a portion of the catalyst housing and at least a portion of the compressor housing and at least a portion of the turbine housing may be integrally formed. This results in a mechanically robust and compact structure for the entire turbocharger.

In some embodiments of the invention, a heat flow of about 0.5 kW to about 6 kW can be introduced into the heated catalytic converter due to the thermal contact between the catalyst housing on the one hand and the compressor housing or the turbine housing on the other hand. In other embodiments of the invention, the heat flow introduced into the heated catalytic converter by the thermal contact can be between approximately 1 kW and approximately 4 kW. In yet other embodiments of the invention, the heat input can be between about 0.5 kW and about 3 kW.

The heating capacities mentioned allow the efficient vaporization and/or conversion of fuel in the heating catalyst without additional auxiliary electrical energy. the burning engine can therefore be operated in a consumption-optimized manner.

The invention is to be explained in more detail below with reference to figures without restricting the general inventive idea. while showing

FIG. 1 shows a first embodiment of the turbocharger according to the invention in a first view.

FIG. 2 shows the first embodiment of the turbocharger according to the invention in a second view.

FIG. 3 shows the first embodiment of the turbocharger according to the invention in a third view.

FIG. 4 shows a second embodiment of the turbocharger according to the invention in a first view.

FIG. 5 shows the second embodiment of the turbocharger according to the invention in a second view.

FIG. 6 shows a block diagram of an internal combustion engine with an exhaust gas aftertreatment device and a turbocharger according to the invention.

A first embodiment of the turbocharger according to the invention is explained with reference to FIGS. The turbocharger 1 includes a compressor assembly 2, which is set up for compressing the fresh air required for combustion of an internal combustion engine. In the illustrated embodiment, the compressor assembly 2 is designed as a radial compressor. The compressor arrangement 2 has a fresh air inlet 201 which is set up to draw in ambient air at a first pressure. Furthermore, the compressor arrangement 2 has a fresh air outlet 202, which is set up to to deliver sealed fresh air with a second pressure. The fresh air outlet 202 can then be connected to the intake manifold of an internal combustion engine and the fresh air required for combustion of the fuel in the internal combustion engine can be supplied to the internal combustion engine at increased pressure.

An exhaust gas turbine 3 with at least one turbine housing 30 is used to drive the compressor arrangement. The turbine housing 30 has an exhaust gas inlet 301 and an exhaust gas outlet 302, with at least one turbine wheel being arranged in the turbine housing 30 . The exhaust gas turbine is in the illustrated embodiment as a radial turbine leads out, d. H. the exhaust gas inlet 301 and the exhaust gas outlet 302 are arranged approximately at right angles to one another.

In some embodiments of the invention, the turbine housing 30 and the compressor housing 20 can be produced in one piece, for example as a casting or in a 3D printing process. In other embodiments of the invention, the housings can be designed in multiple parts or can be separated and connected to one another by means of screw connections.

In the figures 1 to 3, a heated catalyst 4 is also shown. The heated catalytic converter 4 has a housing 40 with an approximately cylindrical basic shape. On the underside of the housing 4 there is a gas inlet 401 through which exhaust gas and/or fresh air can be supplied to the heated catalytic converter 4 . Furthermore, the heated catalytic converter 4 has at least one fuel inlet 403 . A gaseous or liquid fuel, usually petrol or diesel, can be supplied via the fuel inlet 403 . The fuel can be completely or partially converted in the manner described above with the exhaust gas or the fresh air supplied via the gas inlet 401 . That The product gas generated in this way in the heated catalytic converter 4 leaves the heated catalytic converter 4 via the gas outlet 402.

Furthermore, a bracket 43 can be seen in Figures 1 to 3, which can be made of a thermally conductive material, such as a metal or an alloy. The bracket is set up to mechanically fix the catalytic converter housing 40 of the heated catalytic converter 4 . An end of the bracket 43 facing away from the catalyst housing 40 is in mechanical and thermally conductive contact with the turbine housing 30. During operation of the turbocharger, the turbine housing 30 has hot exhaust gas flowing through it. As a result, the turbine housing 30 heats up. Some of the heat is given off to the environment by convection and radiation. However, part of the heat introduced into the turbine housing 30 flows via the bracket 43 and the partial surface 45 formed between the catalytic converter housing 40 and the bracket 43 into the heated catalytic converter 4. For this purpose, the catalytic converter housing 40 can be at least partially made of a thermally conductive material, for example a metal or alloy. In this way, the heated catalytic converter 4 can be brought to an elevated temperature without or with a reduced supply of electrical auxiliary energy, at which the conversion of the fuel with fresh air or exhaust gas can take place.

As can also be seen in the figures, the catalyzer housing 40 can also have additional connections 41 . Temperature sensors or electrical heating devices can be connected via this. More than one fuel inlet 403 can optionally be present in order to enable a more homogeneous distribution of the fuel within the heated catalytic converter 4 .

As can further be seen in Figures 1 and 2, the turbocharger according to the present invention further includes a first overflow channel 15 with a first end 151 and a second end 152. The first end 151 is connected to the exhaust gas inlet 301 of the turbine housing 30. In this way, the exhaust gas flow emerging from the internal combustion engine at a comparatively high pressure, for example approximately 3.5 to approximately 5 bar, can be at least partially removed and fed to the heated catalytic converter 4 . For this purpose, the second end 152 of the first overflow channel 15 is connected to the gas inlet 401 of the catalytic converter housing 40 . An optional two-way valve (not shown in the figures) can be located in the overflow channel 15, with which the amount of exhaust gas fed to the heated catalytic converter 4 can be controlled.

Furthermore, the turbocharger according to the first embodiment of the invention contains a third transfer channel 35 with a first end 351 and an opposite second end 352. The first end 351 is connected to the gas outlet 402 of the catalytic converter housing 40. The second end 352 opens with an optional nozzle 353 downstream of the turbine wheel in the turbine housing 30. Downstream of the turbine wheel, on the one hand, there is a lower pressure, since the turbine wheel takes energy from the exhaust gas flow. In addition, the turbine wheel causes turbulence and thus good mixing of the product gas generated in the heated catalytic converter 4 with the main exhaust gas flow. The pressure difference results in a defined flow of exhaust gas through the heated catalytic converter 4 . At the same time, the turbocharger according to the invention has a compact design, which saves installation space and allows existing internal combustion engines to be retrofitted in a simple manner.

A second embodiment of the invention is explained in more detail with reference to FIGS. Identical components of the invention are provided with the same reference symbols, so that the following description is limited to the essential differences of the invention.

As can be seen from Figure 4, the second embodiment dispenses with a bracket 43 for the mechanical and thermal coupling of the turbine housing 30 and the catalytic converter housing 40. According to the second embodiment, the catalytic converter housing 40 is designed in two parts with a lower part 422 and an upper part 421. In the illustrated embodiment the lower part 422 of the catalyst housing 40 is made in one piece together with the turbine housing 30, d. H. During the primary shaping of the turbine housing 30 in a metal casting process, the lower part 422 is also manufactured in the same process step as a homogeneous part of the turbine housing 30 .

Due to the one-piece or monolithic production of the lower part 422 of the catalyst housing 40 and the turbine housing 30, there is no boundary surface on the partial surface 45, which causes a thermal coupling of the two components, which impedes the heat transfer through unevenness, dirt or oxidation. The introduction of heat from the turbine housing 30 into the catalytic converter housing 40 can thereby take place more homogeneously and/or more effectively. In other embodiments of the invention, such a cohesive connection of at least part of the catalyst housing and the turbine housing can also be achieved by soldering, welding or 3D printing.

In the case of monolithic production according to the second embodiment of the invention, the overflow channels 15, 25 and 35 can also be produced in a simple manner by means of recesses or bores in the housing. In addition, two-way or three-way valves can also be integrated into the housing, which can influence the supply of exhaust gas or fresh air on the one hand and the discharge of product gas on the other hand in order to adjust the operating parameters of the heated catalytic converter 4 to be adapted to predeterminable target conditions.

FIG. 6 shows a block diagram of an internal combustion engine 7 with an exhaust gas aftertreatment device 72, 73 and 74 and a turbocharger according to the invention. For reasons of clarity, the compressor arrangement 2, the exhaust gas turbine 3 and the heated catalytic converter 4 are shown spatially separated in FIG. The person skilled in the art is of course familiar with the fact that these components of the invention work together, as described above with reference to FIGS.

The internal combustion engine 7 can be a self-igniting or a spark-ignited internal combustion engine. The internal combustion engine 7 is set up to provide mechanical power by burning fuel with ambient air. The internal combustion engine 7 can be used in a car, a truck, a ship, a construction machine or stationary in a compressor, a generator, a combined heat and power plant or a similar device.

During operation, the internal combustion engine 7 is supplied with fresh or ambient air via an air filter 77 . The fresh air is brought to a higher pressure level in the compressor arrangement 2 . For this purpose, the fresh air is supplied to the fresh air inlet 201 , compressed with a compressor wheel and then supplied to the internal combustion engine 7 via the fresh air outlet 202 .

The compressor arrangement is driven via a rotating shaft 8 whose drive power is provided by an exhaust gas turbine 3 . For this purpose, the exhaust gas from the internal combustion engine 7 is introduced into the exhaust gas turbine via the exhaust gas inlet 301 . The exhaust gas then leaves the exhaust gas turbine 3 via an exhaust gas outlet 302. The exhaust gas is then fed via an exhaust pipe 71 to an exhaust gas after-treatment device, which can reduce soot particles and gaseous pollutants. In the exemplary embodiment shown, the exhaust gas aftertreatment device contains an oxidation catalytic converter 72, which is set up to oxidize hydrocarbons and carbon monoxide. The exhaust gas pretreated in this way reaches a particle filter 73, which retains fine dust. The exhaust gas is then fed into an SCR catalytic converter 74, which reduces nitrogen oxides with the addition of urea. To control or regulate the heated catalytic converter 4 and the internal combustion engine 7, exhaust gas temperatures can be measured at different points using different temperature sensors TIA.

The oxidation catalytic converter 72 and the SCR catalytic converter 74 require elevated temperatures of, for example, more than 250° C. for their operation. The particle filter 73 is also functional at low temperatures, but has to be operated at elevated temperatures from time to time in order to oxidize embedded particles and to regenerate the particle filter in this way. There is therefore a need to bring the exhaust gas flowing in the exhaust gas pipe 71 to predeterminable temperatures or to keep it at elevated temperatures. This can be done according to the prior art by appropriate operating conditions of the internal combustion engine 7, for example by late or Nachein injections. As a result, however, the exhaust behavior is worsened and the fuel requirement of the internal combustion engine 7 increases.

According to the invention, it is therefore proposed to use a heating catalyst 4, which is designed to introduce heat into at least one component 72, 73, 74 of the exhaust gas aftertreatment device. For this purpose, fuel is fed to the heated catalytic converter 4 from a storage tank 74 via an electrically driven pump 46, which fuel is fed into the Catalyst housing 40 of the heated catalyst 4 via a fuel inlet 403 occurs. Within the catalyst housing 4, a catalyst carrier is arranged, which is coated with a catalyst material.

In the simplest case, the fuel entering via the fuel inlet 403 can be vaporized in the heated catalytic converter 4 and leave the catalytic converter housing 4 via the gas outlet 402 . This fuel vapor can be introduced into the exhaust pipe 71 by means of a third overflow channel 35 with a first end 351 and an opposite second end 352, with the turbulence generated by the exhaust gas turbine 3 ensuring effective mixing. The fuel vapor can then be oxidized at the oxidation catalytic converter 72 and/or a downstream component 73 or 74 and release heat there.

In other operating states, the fuel in the heating catalytic converter 4 can be reacted with exhaust gas and/or fresh air, so that either a hot gas or a synthesis gas is formed, which can be fed to the exhaust pipe 71 via the third overflow channel 35 in the same way. A synthesis gas can also be converted at the oxidation catalytic converter 72 or a subsequent component 73, 74, in which case the light-off temperature can be reduced compared to fuel that has evaporated but is chemically unchanged.

In order to convert the fuel with exhaust gas or fresh air, the heated catalytic converter 4 also contains a gas inlet 401. The gas inlet 401 is connected via a three-way valve 53 to a first overflow channel 15 and a second overflow channel 25. The first overflow channel 15 is connected at its first end 151 to the gas inlet 301 of the exhaust gas turbine 3 so that exhaust gas can be removed at a comparatively high pressure level and fed to a connection of the three-way valve 53 . Furthermore, the illustrated embodiment includes a second overflow channel 25, whose first end 251 is connected to the fresh air outlet 202 of the compressor assembly 2 Ver. The opposite second end 252 is connected to a further connection of the three-way valve 53 . Depending on the position of the three-way valve 53, fresh air or exhaust gas or both can be fed into the catalytic converter housing 40 of the heating catalytic converter 4 via the gas inlet 401. The oxygen content in the heated catalytic converter 4 can thus be adjusted by the position of the three-way valve 53, so that the type of conversion of the supplied fuel can be influenced.

Both the conversion of the fuel in the heated catalytic converter 4 and the mere evaporation require thermal energy. This can be generated on the one hand by at least partial oxidation of the fuel in the heated catalytic converter 4 .

In addition, however, this energy can also be realized according to the invention by thermally coupling the heated catalytic converter 4 to the exhaust gas turbine 3 and/or the compressor arrangement 2 .

An electronic control or regulating device 76 is available for controlling the fuel quantity supplied and the three-way valve 53 and, if appropriate, other components of the heated catalytic converter 4 . This can optionally be connected to engine control 75 via a data bus, in order in this way to also take into account the operating conditions of internal combustion engine 7 when activating heated catalytic converter 4 .

The full integration of the heated catalytic converter 4 in the exhaust gas turbocharger also makes it possible to save on additional components. In the embodiment shown, the three-way valve 53 can also be used to replace a wastegate valve. For this purpose, in the event of an impermissible increase in the pressure at the fresh air outlet 202, the fuel supply to the heated catalytic converter 4 can be interrupted and the three-way valve 53 can be opened so that exhaust gas flows through the heated catalyst 4 from the high-pressure side of the exhaust gas turbine 3 to the low-pressure side without additional heat being generated.

Of course, the invention is not limited to the illustrated embodiments. The foregoing description is therefore not to be considered as limiting but as illustrative. It is to be understood in the following claims that a specified feature is present in at least one embodiment of the invention. This does not exclude the presence of other features. If the claims and the above description define “first” and “second” embodiments, this designation is used to distinguish between two similar embodiments without establishing a ranking.

Claims

Expectations

1. Turbocharger (1) with a compressor arrangement (2), which is set up for compressing the fresh air of an internal combustion engine, containing at least one compressor housing (20) with a fresh air inlet (201) and a fresh air outlet (202), wherein in the compressor housing (20) at least one compressor wheel is arranged, and with at least one exhaust gas turbine (3) for driving the compressor arrangement (2), with at least one turbine housing (30) with an exhaust gas inlet (301) and an exhaust gas outlet (302), wherein in the turbine housing (30) at least one turbine wheel is arranged, characterized in that the turbocharger (1) also contains a heated catalytic converter (4) which is set up to at least partially convert supplied fuel with fresh air and/or exhaust gas, the heated catalytic converter (4) having a catalytic converter housing (40 ) with a gas inlet (401) and a gas outlet (402) and a fuel inlet (403), wherein the catalyst housing (40) on the one hand and the compressor housing (20) and/or the turbine housing (30) on the other hand are in thermal contact on at least one partial surface (45).

The turbocharger of claim 1 further including a first transfer passage (15) having a first end (151) and an opposite second end (152), the first end (151) being connected to the exhaust gas inlet (301) of the turbine housing (30). and the second end (152) is connected to the gas inlet (401) of the catalyst housing (40).

3. A turbocharger as claimed in any one of claims 1 to 2 further including a second transfer passage (25) having a first end (251) and an opposite second end

End (252), wherein the first end (251) is connected to the fresh air outlet (202) of the compressor housing (20) and the second end (252) is connected to the gas inlet (401) of the catalyst housing (40).

4. The turbocharger of any one of claims 1 to 3, further including a third transfer passage (35) having a first end (351) and an opposite second end

end (352), the first end (351) being connected to the gas outlet

(402) of the catalyst housing (40) and the second end (352) is connected to the exhaust outlet (302) of the turbine housing (30).

5. Turbocharger according to claim 4, characterized in that at the second end (352) of the third overflow channel (35) at least one nozzle (353) is arranged.

6. Turbocharger according to one of claims 2 to 5, characterized in that a 2-way valve (52) is present in the first overflow channel (15) and/or in the second overflow channel (25) and/or in the third overflow channel (35). .

7. Turbocharger according to one of claims 1 to 6, further comprising a 3-way valve (53) with three inputs/outputs to which the first overflow channel (15) and the second overflow channel (25) and the gas inlet (401) are connected .

8. Turbocharger according to one of claims 1 to 7, characterized in that at least a part (421, 422) of the catalyst housing (40) and either the compressor housing (20) or the turbine housing (30) are made in one piece

9. Turbocharger according to one of claims 1 to 7, characterized in that at least a part (42) of Catalyst housing (40) and the compressor housing (20) and the turbine housing (30) are made in one piece.

10. Turbocharger according to claim 8 or 9, characterized in that the first overflow duct (15) and/or the second overflow duct (25) and/or the third overflow duct (35) at least in sections as a bore in the catalytic converter housing (40) and/or or in the compressor housing (20) and/or in the turbine housing (30).

11. Turbocharger according to one of claims 1 to 10, characterized in that the thermal contact between the catalytic converter housing (40) on the one hand and the compressor housing (20) and/or the turbine housing (30) on the other hand results in a heat flow of about 0.5 kW to about 6 kW or from about 1 kW to about 4 kW or from about 0.5 kW to about 3 kW can be introduced into the catalytic converter housing (40) when exhaust gas flows through the turbine housing (30).

12. Turbocharger according to one of claims 8 to 10, characterized in that the catalyst housing (40) and at least either the compressor housing (20) or the turbine housing (30) are made as a casting.

13. Method for modifying an internal combustion engine with a turbocharger, comprising the following method steps: removal of the existing turbocharger and installation of a turbocharger according to one of claims 1 to 12.