Method for operating an internal combustion engine, exhaust system and motor vehicle

Abstract

The invention relates to a method for operating an internal combustion engine to which an exhaust system (4) is connected, wherein in a first step the internal combustion engine is started, in a second step the exhaust gas is detected by the exhaust gas sensor with regard to an emission characteristic, In a third step, a control signal representing the detected emission characteristic is transmitted to the control unit; in a fourth step, the control unit classifies the emission characteristic; and in a fifth step, if the classification matches the emission characteristic of the e-fuel with the e-fuel additive, the control unit enables driving operation, or if the classification does not match the emission characteristic of the e-fuel with the e-fuel additive, the combustion engine is shut down. Furthermore, the invention relates to an exhaust system (4) and a motor vehicle (2).

Description

[0001] The invention relates to a method for operating an internal combustion engine to which an exhaust system is connected. Furthermore, the invention relates to an exhaust system for discharging exhaust gases from an internal combustion engine into the environment, configured for carrying out the method.

[0002] Due to legal requirements, the use of synthetic fuels, also known as e-fuels, will steadily increase in the coming years. Alongside the use of electric vehicles, this will help reduce CO2 emissions. However, since fossil fuels will remain available on the market alongside e-fuels for some time, the use of e-fuels must be independently verifiable. In this context, it is known from the prior art (see, for example, DE 10 2018 104 258 A1) to install at least one sensor in the exhaust system that detects the exhaust gas and allows a control unit to determine the type of fuel used. It is also known from DE 2019 125 083 A1 to ensure the use of a CO2-reduced fuel by only permitting the use of a vehicle with this fuel.Furthermore, it is known from the generic patent DE 10 2018 202 818 A1 to detect a particle concentration in the exhaust stream using a particle sensor. However, this is a very complex process involving the detection of pressure changes in at least one combustion chamber in order to determine the fuel type. As a consequence, in extreme cases, the combustion engine can be shut down if a fuel not approved for use in the engine is used. Such a function represents a drastic intervention in the engine control system, which can naturally lead to extreme consequences for the vehicle user. On the other hand, it must be ensured that legal requirements are met and cannot be circumvented. Simply measuring fuel quality can lead to inaccurate results due to impurities, additives, etc.In principle, it is also known from DE 10 2008 006 798 B3 to add a marker to a fuel in order to inform a vehicle user about the fuel used.

[0003] The object of the invention is therefore to avoid the aforementioned disadvantages in a simple and cost-effective way.

[0004] The object of the invention is achieved by starting the combustion engine in a first step, detecting the exhaust gas with regard to an emission characteristic by the exhaust gas sensor in a second step, transmitting a control signal representing the detected emission characteristic to the control unit in a third step, classifying the emission characteristic in a fourth step, and enabling driving operation in a fifth step if the classification matches the emission characteristic of the e-fuel with the e-fuel additive, or if the classification does not match the particle number of the e-fuel with the e-fuel additive, shutting down the combustion engine.The emission characteristics can be used to map particle number, color, fluorescence and / or wavelength.

[0005] Furthermore, the problem is solved by an exhaust system for discharging exhaust gases from an internal combustion engine into the environment, configured for carrying out the method, wherein at least one exhaust manifold, an exhaust pipe system, an exhaust aftertreatment arrangement, an exhaust silencer arrangement and a control device configured to classify the emission characteristics are provided, which at least controls the exhaust aftertreatment and controls the operating mode, i.e. driving operation or standstill of the internal combustion engine, depending on at least one sensor signal from at least one exhaust gas sensor, wherein a defined sensor signal enables driving operation, wherein the at least one exhaust gas sensor detects a defined number of particles and thus a defined smoke development of a combusted e-fuel fuel, wherein an e-fuel additive to be detected is added and the exhaust gas sensor is designed as an optical sensor.

[0006] Advantageously, the exhaust gas sensor is integrated into the exhaust system. Such an arrangement is easy to implement and, if necessary, very easy to retrofit.

[0007] Alternatively or additionally, the exhaust gas sensor can be integrated into the exhaust aftertreatment system. In this case, a control line to a control unit should already be present, which significantly reduces the effort required for assembly and manufacturing.

[0008] The task is also solved by a motor vehicle equipped with such a fuel supply system.

[0009] The invention is explained in more detail with reference to a drawing, in which the single figure shows a side view of a motor vehicle with a schematically represented fuel supply device.

[0010] A motor vehicle 2 has a known exhaust system 4 for discharging exhaust gases from an internal combustion engine 6 into the environment. In the exemplary embodiment, the exhaust system 4 has a known exhaust manifold 8, which connects to the internal combustion engine 6. From the exhaust manifold 8, the exhaust gas is guided through an exhaust pipe system 10 via an integrated exhaust aftertreatment arrangement 12 to an exhaust silencer arrangement 14, from where the cleaned exhaust gas is released into the environment. Furthermore, a known control device 16 is provided, which, among other things, controls the exhaust aftertreatment arrangement 12 for the exhaust gas to be discharged from the internal combustion engine 6 and, in the event of a fault in the exhaust aftertreatment arrangement 12, stops the vehicle by shutting down the internal combustion engine 6.

[0011] In order to be able to unambiguously detect a prescribed e-fuel with an e-fuel additive, an optical sensor 18 is provided as an exhaust gas sensor in the exhaust aftertreatment arrangement 12 in the present embodiment. In the present embodiment, the optical sensor 18 detects a continuously changing, harmless emission characteristic due to the combusted e-fuel additive.

[0012] According to a method according to the invention, in a first step the internal combustion engine 6 is started. The exhaust gas produced is routed via the exhaust system 10 to the exhaust aftertreatment system and, in a second step, detected by the optical sensor 18 with regard to the number of particles. In a third step, a control signal representing the detected emission characteristic is transmitted to the control unit 16. Subsequently, in a fourth step, the control unit 16 classifies the detected emission characteristic. Then, in a fifth step, if the classification matches the emission characteristic of the e-fuel with the e-fuel additive, driving operation is enabled. If the classification does not match the emission characteristic of the e-fuel with the e-fuel additive, the internal combustion engine 6 is shut down.

[0013] To sustainably alter the emission characteristics without changing the calorific value, a variety of additives can be used. For example, sulfur-containing additives cause increased smoke formation, which is accompanied by a higher number of detectable particles. Aromatic hydrocarbons cause increased soot formation, which also results in a higher number of particles.

[0014] The use of metal salts or organic dyes as e-fuel additives results in colored smoke. For example, copper compounds such as copper chloride or copper sulfate produce blue or green smoke, strontium compounds, such as strontium nitrate, produce red smoke, and barium compounds, such as barium chloride or barium nitrate, produce green smoke.

[0015] The use of fluorescent substances produces fluorescent exhaust gas, the degree of fluorescence of which must be detected. Examples of substances that can be used include anthracene, a polycyclic aromatic hydrocarbon that fluoresces blue under UV light; naphthalene derivatives, which exhibit fluorescent properties at certain concentrations; and phthalimide derivatives, whose compounds also fluoresce under UV light.

[0016] Organometallic compounds can also be used to change the wavelength, i.e., the color of the exhaust gas. Examples include strontium chloride for red flames, copper chloride for green / bluish flames, sodium chloride (table salt) for yellow flames, and potassium chloride for violet flames. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2018 104 258 A1

[0002] DE 2019 125 083 A1

[0002] DE 10 2018 202 818 A1

[0002] DE 10 2008 006 798 B3

[0002]

Claims

[1] Method for operating an internal combustion engine to which an exhaust system (4) is attached, wherein In the first step, the combustion engine is started, In a second step, the exhaust gas is detected by the exhaust gas sensor with regard to its emission characteristics, In a third step, a control signal representing the detected emission characteristics is transmitted to the control unit. In a fourth step, the control unit performs a classification of the emission characteristics, and in a fifth step, if the classification matches the emission characteristics of the e-fuel fuel with the e-fuel additive, the control unit enables driving operation, or if the classification does not match the emission characteristics of the e-fuel fuel with the e-fuel additive, the combustion engine is shut down. [2] Method according to claim 1, characterized by , that the emission characteristics depict a particle number or a particle characteristic, such as a color or wavelength and / or a fluorescence. [3] Exhaust system for discharging exhaust gases from an internal combustion engine (6) into the environment for carrying out the method, wherein at least one exhaust manifold (8), an exhaust duct system (10), an exhaust aftertreatment arrangement (12), an exhaust silencer arrangement (14) and a control device (16) configured to classify the emission characteristics are provided, which at least controls the exhaust aftertreatment and controls the operating mode, i.e. driving operation or standstill of the internal combustion engine (6), depending on at least one sensor signal from at least one exhaust gas sensor (18) designed as an optical sensor, wherein a defined sensor signal enables driving operation, wherein the at least one exhaust gas sensor (18) detects a defined emission characteristic and thus a defined exhaust gas composition of a combusted e-fuel fuel, wherein an e-fuel additive to be detected is added. [4] Exhaust system according to claim 3, characterized by , that the exhaust gas sensor (18) is provided in the exhaust gas system (10). [5] Exhaust system according to claim 3, characterized by , that the exhaust gas sensor (18) is provided in the exhaust gas aftertreatment arrangement (12). [6] Motor vehicle with an exhaust system (4) according to any of the preceding claims.

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