Turbocharger

Abstract

A turbocharger has compressor arrangement configured to compress the fresh air of an internal combustion engine. The turbocharger has at least one compressor housing (with a fresh air inlet) and a fresh air outlet. At least one compressor impeller is arranged in the compressor housing, and with at least one exhaust gas turbine for driving the compressor arrangement, with at least one turbine housing with an exhaust gas inlet and an exhaust gas outlet. At least one turbine wheel is arranged in the turbine housing. A heated catalytic converter is configured to at least partially convert supplied fuel with fresh air and/or exhaust gas. The heated catalytic converter includes a catalytic converter housing with a gas inlet and a gas outlet and a fuel inlet. The catalytic converter housing and the compressor housing and/or the turbine housing are in thermal contact on at least one part surface.

Claims

1. A turbocharger (1) comprising: a compressor arrangement (2) configured to compress fresh air entering an internal combustion engine, the compressor arrangement comprising at least one compressor housing (20) having a fresh air inlet (201), a fresh air outlet (202), and at least one compressor impeller arranged in the compressor housing (20); at least one exhaust gas turbine (3) configured to drive the compressor arrangement (2), the at least one exhaust gas turbine comprising at least one turbine housing (30) having an exhaust gas inlet (301), an exhaust gas outlet (302), and at least one turbine wheel being arranged in the turbine housing (30); a heated catalytic converter (4) configured to at least partially convert supplied fuel with fresh air and/or exhaust gas, the heated catalytic converter (4) comprising a catalytic converter housing (40) having a gas inlet (401) and a gas outlet (402) and a fuel inlet (403); and a third overflow channel (35) having a first end (351) connected to the gas outlet (402) of the catalytic converter housing (40) and a second end (352) connected to the exhaust gas outlet (302) of the turbine housing (30), such that a product gas generated in the heated catalytic converter (4) bypasses the turbine (3) and is directed into an exhaust pipe (71) downstream of the turbine (3), via the third overflow channel (35); wherein: the catalytic converter housing (40) and the compressor housing (20) are in thermal contact on at least one part surface (45); and/or the catalytic converter housing (40) and the turbine housing (30) are in thermal contact on at least one part surface (45).

2. A turbocharger according to claim 1, further comprising: a first overflow channel (15) having a first end (151) and an opposite second end (152), wherein the first end (151) is 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 catalytic converter housing (40).

3. A turbocharger according to claim 2, further comprising: a second overflow channel (25) having a first end (251) and an opposite second 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 catalytic converter housing (40).

4. A turbocharger according to claim 3, further comprising: a 3-way valve (53) with three inlets/outlets, to which the first overflow channel (15), the second overflow channel (25) and the gas inlet (401) are connected.

5. A turbocharger according to claim 1, wherein: at least one nozzle (353) is arranged on the second end (352) of the third overflow channel (35).

6. A turbocharger according to claim 1, wherein: the first overflow channel (15) and/or the second overflow channel (25) and/or the third overflow channel (35) is designed at least in sections as a bore in the catalytic converter housing (40) and/or in the compressor housing (20) and/or in the turbine housing (30).

7. A turbocharger according to claim 1, wherein: 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).

8. A turbocharger according to claim 1, wherein: at least one part (422) of the catalytic converter housing (40), the compressor housing (20) and the turbine housing (30) are manufactured together in one piece to have monolithic construction.

9. A turbocharger according to claim 8, wherein: the first overflow channel (15) and/or the second overflow channel (25) and/or the third overflow channel (35) is designed at least in sections as a bore in the catalytic converter housing (40) and/or in the compressor housing (20) and/or in the turbine housing (30).

10. A turbocharger according to claim 1, wherein: at least one part (421, 422) of the catalytic converter housing (40) and either the compressor housing (20) or the turbine housing (30) are manufactured together in one piece to have monolithic construction.

11. A turbocharger according to claim 10, wherein: the catalytic converter housing (40) and at least either the compressor housing (20) or the turbine housing (30) are manufactured as a cast part.

12. A turbocharger according to claim 1, wherein: at least one part (422) of the catalytic converter housing (40), the compressor housing (20) and the turbine housing (30) are manufactured together in one piece to have monolithic construction.

13. A turbocharger according to claim 1, wherein: at least one part (421, 422) of the catalytic converter housing (40) and either the compressor housing (20) or the turbine housing (30) are manufactured together in one piece to have monolithic construction.

14. A turbocharger according to claim 13, wherein: the catalytic converter housing (40) and at least either the compressor housing (20) or the turbine housing (30) are manufactured as a cast part.

15. A turbocharger according to claim 1, wherein: when exhaust gas flows through the turbine housing (30), a heat flow of about 0.5 kW to about 6 kW is introduced into the catalytic converter housing (40) by thermal contact between: (a) the catalytic converter housing (40) and the compressor housing (20); and/or (b) the catalytic converter housing (40) and the turbine housing (30).

16. A method for modifying an internal combustion engine having a turbocharger, comprising: removing the existing turbocharger and installing a turbocharger is accordance with claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention shall be explained in more detail below on the basis of drawings without limiting the general concept of the invention. Here,

(2) FIG. 1 shows a first view of a first embodiment of the turbocharger according to the invention.

(3) FIG. 2 shows a second view of the first embodiment of the turbocharger according to the invention.

(4) FIG. 3 shows a third view of the first embodiment of the turbocharger according to the invention.

(5) FIG. 4 shows a first view of a second embodiment of the turbocharger according to the invention.

(6) FIG. 5 shows a second view of the second embodiment of the turbocharger according to the invention.

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

DETAILED DESCRIPTION

(8) FIGS. 1 to 3 illustrate a first embodiment of the turbocharger according to the invention. The turbocharger 1 contains a compressor arrangement 2, which is designed to compress the fresh air required for combustion in an internal combustion engine. In the illustrated exemplary embodiment, the compressor arrangement 2 is designed as a radial compressor. The compressor arrangement 2 has a fresh air inlet 201, which is designed to draw in ambient air at a first pressure. Furthermore, the compressor arrangement 2 has a fresh air outlet 202, which is designed to discharge the compressed fresh air at a second pressure. The fresh air outlet 202 can then be connected to the intake manifold of an internal combustion engine and supply the fresh air required for the combustion of the fuel in the internal combustion engine to the internal combustion engine at increased pressure.

(9) An exhaust gas turbine 3 having 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, at least one turbine wheel being arranged in the turbine housing 30. In the illustrated exemplary embodiment, the exhaust gas turbine is also designed as a radial turbine, i.e. the exhaust gas inlet 301 and the exhaust gas outlet 302 are arranged approximately at right angles to one another.

(10) In some embodiments of the invention, the turbine housing 30 and the compressor housing 20 can be manufactured in one piece, for example as a cast part or in a 3D printing method. In other embodiments of the invention, the housings can be made in several parts or be separated and connected to one another by means of screw connections.

(11) FIGS. 1 to 3 also show a heated catalytic converter 4. The heated catalytic converter 4 has a housing 40 having a roughly cylindrical main shape. A gas inlet 401 is located on the underside of the housing 4, 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 gasoline or diesel, can be supplied via the fuel inlet 403. The fuel can be completely or partially converted in the above described manner with the exhaust gas or fresh air supplied via the gas inlet 401. The product gas generated in the heated catalytic converter 4 in this way leaves the heated catalytic converter 4 via the gas outlet 402.

(12) Furthermore, FIGS. 1 to 3 show a holding bracket 43, which can be made of a thermally conductive material, for example a metal or an alloy. The holding bracket is designed to mechanically fix the catalytic converter housing 40 of the heated catalytic converter 4. One end of the holding bracket 43 facing away from the catalytic converter housing 40 is in mechanical and thermally conductive contact with the turbine housing 30. During operation of the turbocharger, hot exhaust gas flows through the turbine housing 30. This causes the turbine housing 30 to heat up. Some of the heat is released into the environment by convection and radiation. However, some of the heat introduced into the turbine housing 30 flows into the heated catalytic converter 4 via the holding bracket 43 and the part surface 45 formed between the catalytic converter housing 40 and the holding bracket 43. For this purpose, the catalytic converter housing 40 can be made at least partially from a thermally conductive material, for example a metal or an alloy. In this way, the heated catalytic converter 4 can be brought without or with a reduced supply of electrical auxiliary energy to an increased temperature, at which the fuel can be converted with fresh air or exhaust gas.

(13) As can also be seen in the drawings, the catalytic converter housing 40 can also have further ports 41. Temperature sensors or electrical heating devices can be connected via these ports. Optionally, more than one fuel inlet 403 can be provided to render possible a more homogeneous distribution of the fuel within the heated catalytic converter 4.

(14) As further shown in figures land 2, the turbocharger according to the present invention also contains a first overflow passage 15 having 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 leaving the internal combustion engine at a comparatively high pressure, for example about 3.5 to about 5 bar, can be at least partially extracted and supplied 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 drawings) can be located in the overflow channel 15, by means of which valve the amount of exhaust gas supplied to the heated catalytic converter 4 can be controlled.

(15) Furthermore, the turbocharger according to the first embodiment of the invention includes a third overflow channel 35 having a first end 351 and an opposite second end 352. The first end 351 is here 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. Thus, as best seen in FIG. 6, a product gas emerging from the catalytic converter 4 at gas outlet 402 bypasses the turbine 3 and is directed into the exhaust pipe 71 downstream of the turbine 3, via the third overflow channel 35. Downstream of the turbine wheel, a lower pressure is created on the one hand, since the turbine wheel draws energy from the exhaust gas flow. In addition, the turbine wheel causes turbulence and therefore 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 makes it easy to retrofit existing internal combustion engines.

(16) FIGS. 4 and 5 illustrate a second embodiment of the invention in more detail. Identical components of the invention are provided with identical reference signs so that the following description is limited to the essential differences of the invention.

(17) As is clear from FIG. 4, the second embodiment dispenses with a holding 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 exemplary embodiment, the lower part 422 of the catalytic converter housing 40 is manufactured in one piece together with the turbine housing 30, i.e. during the primary forming of the turbine housing 30 in a metal casting method, the lower part 422 is also manufactured in the same method step as a homogeneous component of the turbine housing 30.

(18) Due to the one-piece or monolithic production of the lower part 422 of the catalytic converter housing 40 and the turbine housing 30, there is no interface at the part surface 45, which causes thermal coupling of the two components and impedes heat input due to unevenness, contamination or oxidation. The heat input from the turbine housing 30 to the catalytic converter housing 40 can therefore be more homogeneous and/or more effective. In other embodiments of the invention, such an integrally bonded connection of at least one part of the catalytic converter housing and the turbine housing can also be achieved by soldering, welding or 3D printing.

(19) In the case of the 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 recesses or bores in the housing. In addition, two-way or three-way valves can also be integrated into the housing and can influence the supply of exhaust gas or fresh air on the one hand and the removal of product gas on the other hand in order to adapt the operating parameters of the heated catalytic converter 4 to predeterminable target conditions.

(20) FIG. 6 shows a block diagram of an internal combustion engine 7 having 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 spatially separated in FIG. 6. A person skilled in the art is of course aware that these components of the invention work together, as described above with reference to FIGS. 1 to 5.

(21) The internal combustion engine 7 can be a self-ignition or spark-ignition internal combustion engine. The internal combustion engine 7 is designed 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 in stationary fashion in a compressor, a generator, a combined heat and power unit or a similar device.

(22) 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 impeller and then supplied to the internal combustion engine 7 via the fresh air outlet 202.

(23) The compressor arrangement is driven by a rotating shaft 8, the drive power of which is provided by an exhaust gas turbine 3. For this purpose, the exhaust gas from the internal combustion engine 7 is supplied 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.

(24) The exhaust gas is then supplied via an exhaust pipe 71 to an exhaust gas aftertreatment device, which can reduce soot particles and gaseous pollutants. In the illustrated exemplary embodiment, the exhaust gas aftertreatment device contains an oxidation catalytic converter 72, which is designed to oxidize hydrocarbons and carbon monoxide. The exhaust gas pre-treated in this way reaches a particulate filter 73, which retains fine dust particles. The exhaust gas is then supplied into an SCR catalytic converter 74, which reduces nitrogen oxides with the addition of urea. Exhaust gas temperatures can be measured at different points using various temperature sensors TIA to control the heated catalytic converter 4 and the internal combustion engine 7 in an open-loop or closed-loop fashion.

(25) The oxidation catalytic converter 72 and the SCR catalytic converter 74 require elevated temperatures of more than 250 C., for example, in order to operate. The particulate filter 73 is also functional at low temperatures, but must be operated at elevated temperatures from time to time in order to oxidize embedded particles and regenerate the particulate filter in this way. There is therefore a need to bring the exhaust gas flowing in the exhaust pipe 71 to predeterminable temperatures or to keep it at elevated temperatures. According to the prior art, this can be achieved by appropriate operating conditions of the internal combustion engine 7, for example by late or post-injection. However, this worsens the exhaust gas behavior and increases the fuel requirement of the internal combustion engine 7.

(26) According to the invention, it is therefore proposed to use a heated catalytic converter 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 supplied to the heated catalytic converter 4 from a storage tank 79 via an electrically driven pump 46, which fuel enters the catalytic converter housing 40 of the heated catalytic converter 4 via a fuel inlet 403. A catalytic converter support, which is coated with a catalyst material, is arranged inside the catalytic converter housing 4.

(27) 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. By means of a third overflow channel 35 having a first end 351 and an opposite second end 352, this fuel vapor can be introduced into the exhaust pipe 71, the turbulence generated by the exhaust gas turbine 3 ensuring effective mixing. The fuel vapor can then be oxidized at the oxidation catalyst 72 and/or a downstream component 73 or 74, where it releases heat.

(28) In other operating states, the fuel can be converted in the heated catalytic converter 4 with exhaust gas and/or fresh air so that either a hot gas or a synthesis gas is formed, which can be supplied 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 downstream component 73, 74, it being possible that the light-off temperature is reduced compared to vaporized but chemically unchanged fuel.

(29) 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 via its first end 151 to the gas inlet 301 of the exhaust gas turbine 3 so that exhaust gas can be extracted at a comparatively high pressure level and supplied to a port of the three-way valve 53. Furthermore, the illustrated embodiment contains a second overflow channel 25, the first end 251 of which is connected to the fresh air outlet 202 of the compressor arrangement 2. The opposite second end 252 is connected to a further port of the three-way valve 53. Depending on the position of the three-way valve 53, fresh air or exhaust gas or both can thus be supplied into the catalytic converter housing 40 of the heated 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.

(30) Both the conversion of the fuel in the heated catalytic converter 4 and the mere vaporization require thermal energy which can, on the one hand, can be generated 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 thermal coupling of the heated catalytic converter 4 to the exhaust gas turbine 3 and/or the compressor arrangement 2.

(31) An electronic open-loop or closed-loop control device 76 is available for driving the amount of fuel supplied and the three-way valve 53 and, if necessary, further components of the heated catalytic converter 4. This device can optionally be connected to the engine control unit 75 via a data bus so that the operating conditions of the internal combustion engine 7 can also be taken into account when driving the heated catalytic converter 4.

(32) The complete integration of the heated catalytic converter 4 into the exhaust gas turbocharger also makes it possible to save on additional components. In the illustrated exemplary embodiment, the three-way valve 53 can also be used to replace a wastegate valve. For this purpose, if the pressure at the fresh air outlet 202 rises unacceptably, 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 catalytic converter 4 from the high-pressure side of the exhaust gas turbine 3 to the low-pressure side without generating additional heat.

(33) Of course, the invention is not limited to the illustrated embodiments. Therefore, the above description should not be regarded as restrictive but as explanatory. The following claims are to be understood in such a way that a stated feature is present in at least one embodiment of the invention. This does not exclude the presence of further features. If the claims and the above description define first and second embodiments, this designation is used to distinguish between two similar embodiments without determining a ranking order.