INTERNAL COMBUSTION ENGINE

Abstract

To enable an improved operating behavior of an internal combustion engine, an internal combustion engine having at least one combustion chamber, having at least one air inlet section for the supply of air into the combustion chamber, having at least one exhaust gas outlet for the discharge of exhaust gas into at least one exhaust gas tube, having at least one optical particulate measurement sensor, and having a control apparatus for controlling an operating behavior of the internal combustion engine is provided, wherein the optical particulate measurement sensor is provided to determine a particulate concentration in the exhaust gas and to make available at least one particulate concentration signal for the control apparatus derived from the particulate concentration and wherein the control apparatus is configured to directly change the operating behavior of the internal combustion engine based on the particulate concentration signal of the optical particulate measurement sensor.

Claims

1. An internal combustion engine, the internal combustion engine having at least one combustion chamber, having at least one air inlet section for the supply of air into a combustion chamber, having at least one exhaust outlet or discharging exhaust gas into at least one exhaust gas tube, having at least one optical particulate measurement sensor, and having a control apparatus for controlling an operating behavior of the internal combustion engine, wherein the optical particulate measurement sensor is provided for determining a particulate concentration in the exhaust gas and for making available at least one particulate concentration signal for the control apparatus, with the at least one particulate concentration signal being derived from the particulate concentration; and wherein the control apparatus is configured to directly change the operating behavior of the internal combustion engine based on the particulate concentration signal of the optical particulate measurement sensor.

2. The internal combustion engine in accordance with claim 1, wherein the optical particulate measurement sensor is arranged at the exhaust gas outlet or at the exhaust gas tube.

3. The internal combustion engine in accordance with claim 2, wherein the optical particulate measurement sensor is arranged at an exhaust gas manifold directly after the internal combustion chamber and/or in front of an exhaust gas filter system.

4. The internal combustion engine in accordance with claim 1, wherein the optical particulate measurement sensor is configured to determine the particulate concentration on the basis of a particulate density measurement value in combination with a through-flow measurement value.

5. The internal combustion engine in accordance with claim 1, wherein, in accordance with the particulate concentration signal of the optical particulate measurement sensor, the control apparatus is configured to reduce an amount of a returned exhaust gas for a particulate concentration lying above a normalized value or to increase an amount of the returned exhaust gas on a particulate concentration lying below the normalized value.

6. The internal combustion engine in accordance with claim 1, wherein the control apparatus is configured to reduce or to increase a feed volume of the air in the air inlet section in accordance with the particulate concentration signal of the optical particulate measurement sensor.

7. The internal combustion engine in accordance with claim 1, wherein the control apparatus is configured to directly change a supply of a fuel in accordance with the particulate concentration signal of the particulate measurement sensor.

8. The internal combustion engine (M) in accordance with claim 5, wherein the control apparatus is configured to reduce or to increase a feed volume of the air in the air inlet section in accordance with the particulate concentration signal of the optical particulate measurement sensor, wherein the control apparatus is further configured to directly change a supply of a fuel in accordance with the particulate concentration signal of the particulate measurement sensor and wherein, in accordance with the particulate concentration signal of the particulate measurement sensor, the control apparatus is configured to directly change the return of the exhaust gas and/or the feed volume of the air in the air inlet section and/or the supply of the fuel in the sense of an optimized combustion.

9. The internal combustion engine in accordance with claims 1, wherein the optical particulate measurement sensor is a scattered light sensor.

10. The internal combustion engine in accordance with claim 1, wherein the direct change of the operating behavior of the internal combustion engine can be carried out in accordance with the particulate concentration signal of the particulate measurement sensor by way of the control apparatus in real time without a comparison to an engine operating characteristic field.

11. A method of controlling an internal combustion engine, the method comprising the steps of: determining a particulate concentration in the exhaust gas by means of an optical particulate measurement sensor; making available at least one particulate concentration signal for a control apparatus, with the at least one particulate concentration signal being derived from the particulate concentration; and directly changing an operating behavior of the internal combustion engine based on the particulate concentration signal of the particulate measurement sensor.

Description

[0023] In the following the invention will be explained in detail with reference to embodiments on the basis of the drawing. The drawing shows:

[0024] FIG. 1 a schematic illustration of a preferred embodiment of an internal combustion engine in accordance with the invention.

[0025] In the FIG. 1 a schematic illustration of a preferred embodiment of an internal combustion engine M in accordance with the invention is shown that in the illustrated embodiment comprises four combustion chambers 1 more specifically four cylinders. At an inlet side of the combustion engine M an air inlet section 2 is provided that is connected to the combustion chambers 1 and serves for the supply of air into the combustion chambers 1.

[0026] Preferably at least one air compressor VD is provided at the air inlet section 2 in such a way that the sucked in air can be compressed for an improved combustion. Preferably vanes of the air compressor VD can be adjusted in order to enable the adaptation of a feed amount, of a flow of an amount of air and of an air pre-pressure in the engine control respectively of a control apparatus 6.

[0027] At an outlet side of the internal combustion engine M an exhaust gas outlet 3 is provided that is connected to the combustion chambers 1 and serves for the discharge of exhaust gas from the combustion chambers 1 into at least one exhaust gas tube 4. A non-illustrated exhaust gas post-treatment system is provided in the exhaust gas tube 4 that, for example, comprises catalytic converters, in particular so-called diesel oxidation catalytic converters (DOC catalytic converters) or selective catalytic reduction catalytic converters (SCR catalytic converters) or particulate filters. Additionally an exhaust gas return 5 is connected to the air inlet section 2. The exhaust gas outlet 3 in the sense of the invention comprises a manifold and a section between the manifold and the exhaust gas tube 4 that is arranged in front of the exhaust gas return 5.

[0028] The internal combustion engine M is controlled in its operating behavior by means of the control apparatus 6. For this purpose the control apparatus 6 receives state measurement data of the internal combustion engine M from different sensors, such as for example, pressure sensors or temperature sensors, in such a way that the control apparatus 6 can control an ideal operating behavior of the internal combustion engine M on the basis of stored characteristics of amounts of air fuel supplied into the combustion chambers 1 or ignition times in the combustion chambers 1.

[0029] In accordance with the invention at least one optical particulate measurement sensor 7 is provided that determines a particulate concentration in the exhaust gas. In this connection a portion of non-combusted air fuel mixture in the exhaust gas and in particular incomplete combusted components of the air fuel mixture in the exhaust gas, generally referred to as carbon black, are understood as the particulate concentration in accordance with the invention.

[0030] The optical particulate measurement sensor 7 makes available at least one particulate concentration signal for the control apparatus 6 that is derived from the measured particulate concentration in the exhaust gas. This means a control apparatus 6 directly derives control signals from the particulate concentration signal of the optical particulate measurement sensor 7 in order to directly and in real time change the operating behavior of the internal combustion engine M in such a way that the particulate concentration is reduced to approximately zero.

[0031] In other words, if the optical particulate measurement sensor 7 determines a very small number of particulates in the exhaust gas that lies beneath a threshold and/or a threshold value, then the control apparatus receives a particulate concentration signal that represents an ideal combustion in such a way that no change is required in the operating behavior of the internal combustion engine M.

[0032] If the optical particulate measurement sensor 7 determines a high number of particulates in the exhaust gas, then the control apparatus 6 receives a particulate concentration signal that represents an incomplete combustion in such a way that the control apparatus 6 increases an oxygen supply at the air inlet section 2 by means of the air compressor VD based on the particulate concentration signal and the exhaust gas return 5 in order to reduce an exhaust gas return rate in such a way that the combustion is optimized and the particulate development is reduced in the combustion chambers 1.

[0033] If the optical particulate measurement sensor 7 determines too high a gradient of initially a few particulates leading thereafter to many particulates, this means to a too fast increase of particulates in the exhaust gas, then the control apparatus 6 receives a particulate concentration signal that represents a too fast varying incomplete combustion in such a way that the control apparatus 6, for example, controls a non-illustrated fuel injection system with reference to the particulate concentration signal, in order to induce a fast reduction of an injection pressure of the fuel and to increase a pressure of the air compressor VD in order to increase the oxygen supply at the air inlet section 2.

[0034] Furthermore, the control apparatus 6 controls the exhaust gas return 5 on the basis of the particulate concentration signal in order to reduce the exhaust gas return rate. Due to the coordinated measures based on the particulate concentration signal of the optical particulate measurement sensor 7, the incomplete combustion in the internal combustion engine M is compensated towards an ideal combustion and the generation of particulates is significantly reduced.

[0035] If the optical particulate measurement sensor 7 determines too high a gradient of many particulates to too few particulates, this means a too fast reduction of the number of particulates in the exhaust gas, then the control apparatus 6 receives a particulate concentration signal that represents a too fast varying complete combustion leading to a too lean mixture possibly with too high an oxygen excess in such a way that the control apparatus 6, for example, induces a reduction of the pressure of the air compressor VD with reference to the particulate concentration signal and controls the exhaust gas return 5 in order to increase the exhaust gas return rate. Thereby the ideal power of the internal combustion engine M can be regulated for a minimized fuel consumption.

[0036] Hereby the consumption of fuel and of exhaust gas cleaning materials, for example urea solutions, so-called AdBlue, can be reduced and the lifetime of the exhaust gas cleaning system can be increased. Additionally the control apparatus 6 is in a position to change the operating behavior of the internal combustion engine M fast with reference to the particulate concentration signal based on the particulate concentration in the exhaust gas in such a way that short term effects, such as, instability of the combustion and also long term effects, such as, part wear or chemical aging can be compensated in an improved manner.

[0037] Advantageously the optical particulate measurement sensor 7 is arranged at the exhaust gas tube 4. Preferably, the optical particulate measurement sensor 7 is arranged directly at the manifold after the combustion chambers 1, wherein the optical particulate measurement sensor 7 or a further optical particulate measurement sensor 7 can be provided in front of an exhaust gas filter system.

[0038] Hereby the optical particulate measurement sensor 7 determines the particulate concentration of the exhaust gas on the basis of an extremely fast measurement method, with the optical particulate measurement sensor 7 in particular being a scattering light sensor. This means that a real time analysis of the particulate concentration in the exhaust gas by way of the optical particulate measurement sensor 7 enables the control apparatus 6 to bring about an improved operating behavior of the internal combustion engine M in a fast way. A comparison of the current operating data of the internal combustion engine M with a characteristic field for the purpose of the optimization of combustion is thus omitted.

LIST OF REFERENCE NUMERALS

[0039] 1 combustion chamber

[0040] 2 air inlet section

[0041] 3 exhaust gas outlet

[0042] 4 exhaust gas tube

[0043] 5 exhaust gas return

[0044] 6 control apparatus

[0045] 7 particulate measurement sensor

[0046] M internal combustion engine

[0047] VD air compressor