Method and control unit for operating a diesel internal combustion engine or a dual-fuel internal combustion engine operated in diesel mode - Patents.com

Abstract

To provide a new type method for operating a diesel internal combustion engine or a dual fuel internal combustion engine operated in a diesel operation mode, and a control unit.SOLUTION: A method for operating a diesel internal combustion engine (1) or a dual fuel internal combustion engine (1) operated in a diesel operation mode includes steps of: detecting a measurement value of a total base number and / or a measurement value of viscosity of lubrication oil that is currently used in an oil circuit (3) for lubrication in the operated internal combustion engine (1) to which lubrication oil is supplied via the oil circuit (3); determining oil change amount in the oil circuit (3) depending on the established measurement value of the total base number and / or depending on the established measurement value of the viscosity; removing the currently used lubrication oil from the oil circuit (3) to the extent corresponding to the oil change amount; and supplying new lubrication oil to the oil circuit (3) to the extent corresponding to the oil change amount.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for operating a diesel internal combustion engine or a dual-fuel internal combustion engine operated in diesel mode. Furthermore, the present invention relates to a control unit for operating a diesel internal combustion engine or a dual-fuel internal combustion engine operated in diesel mode. [Background technology]

[0002] The invention herein particularly relates to the range of so-called large engines or large internal combustion engines in which the cylinders have piston diameters of more than 140 mm, in particular more than 175 mm. Such large internal combustion engines are, for example, engines for ships.

[0003] During operation, an internal combustion engine needs to be lubricated with lubricating oil. During this process, the lubricating oil is subject to operation-related aging. This aging can cause the lubricating oil to lose its lubricating effect, which can lead to damage to the internal combustion engine. This must be avoided.

[0004] In the field of so-called large engines, it is customary for a portion of the lubricating oil to enter the combustion chamber of the cylinder, where it is burned together with the fuel for combustion. The consumption of lubricating oil associated with this operation is compensated for, and the lubricating oil circuit is supplied with fresh lubricating oil from time to time, i.e. when too much lubricating oil has been burned, especially in the region of the cylinder. Summary of the Invention [Problem to be solved by the invention]

[0005] Due to the consumption or burning of lubricating oil in the cylinder area and the addition of new lubricating oil to offset this oil consumption, the proper lubricating effect of the lubricating oil is largely maintained in conventional large internal combustion engines, so that complete oil changes in internal combustion engines are not necessary, which involves a large expenditure.

[0006] However, burning lubricating oil in the cylinder area results in a large amount of exhaust gas emissions. Due to increasingly strict emission regulations, it is necessary to avoid burning lubricating oil in the cylinder area. In this case, the need to replenish burned lubricating oil, which is conventionally performed in large internal combustion engines, is reduced. Therefore, in internal combustion engines where as little lubricating oil as possible is burned in the cylinder area to improve exhaust gas emissions, a complete oil change is required, especially if the lubricating oil has become too old. This is costly.

[0007] It must therefore be possible to dispense with complete oil changes even in these new types of internal combustion engines, in which lubricating oil is only burned to a small extent in the region of the cylinders.

[0008] Starting from this, the invention is based on the object of creating a new type of method and control unit for operating a diesel internal combustion engine or a dual-fuel internal combustion engine operated in diesel operating mode. [Means for solving the problem]

[0009] This object is solved by a method for operating a diesel internal combustion engine or a dual-fuel internal combustion engine operated in diesel operating mode according to claim 1.

[0010] According to the present invention, a measured value of the total base number (TBN) or viscosity of the lubricating oil currently used in the lubricating oil circuit is detected. Depending on the measured TBN and / or the measured viscosity, the oil change amount for the oil circuit is determined. The currently used lubricating oil is removed from the oil circuit to the extent of the determined oil change amount. Furthermore, a corresponding amount of fresh lubricating oil is supplied to the oil circuit. The present invention proposes for the first time to measure the total base number (TBN) and / or viscosity of the lubricating oil used. The amount of oil change for the internal combustion engine is determined depending on the respective detected measured values. Next, the lubricating oil is specifically removed from the oil circuit to the extent of the oil change amount, and fresh lubricating oil is supplied to the lubricating oil circuit to the same extent. This allows for reproducible lubricating oil consumption without affecting exhaust gas emissions. The lubricating oil removed from the oil circuit is collected in a collection tank and can then be disposed of or further used. In this way, a complete oil change can be omitted, even in internal combustion engines designed so that little lubricating oil is burned in the cylinder area.

[0011] According to a further development of the invention, the measured values ​​of the total base number and the viscosity of the lubricating oil currently used in the oil circuit for lubrication are detected, and the replacement oil amount for the oil circuit is determined based on the determined measured value of the total base number and based on the determined measured value of the viscosity. Establishing the replacement oil amount based on both measured values, i.e., based on the total base number and on the viscosity of the lubricating oil, is particularly preferred for advantageously determining the replacement oil amount in diesel internal combustion engines or dual-fuel internal combustion engines operated in diesel mode.

[0012] According to a further development of the invention, the replacement oil quantity of the oil circuit is determined as a function of a characteristic diagram or a characteristic curve depending on the established measured value of the total base number and / or depending on the established measured value of the viscosity. Determining the replacement oil quantity as a function of a characteristic diagram or a characteristic curve is particularly simple to carry out. For different support points of the measured values ​​of the total base number and / or viscosity, the replacement oil quantities are stored, and if necessary, an interpolation can be carried out between the individual measured values.

[0013] A control unit for operating a diesel internal combustion engine or a dual-fuel internal combustion engine operated in diesel operating mode is defined in claim 6.

[0014] Preferred further developments of the invention emerge from the dependent claims and the following description.Exemplary embodiments of the invention are explained in more detail with the aid of the drawings, without being limiting thereto. [Brief explanation of the drawings]

[0015] [Figure 1] 1 shows a diagram of an internal combustion engine. DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention relates to a method and a control unit for operating a diesel internal combustion engine or a dual-fuel internal combustion engine operated in diesel operating mode.

[0017] 1 shows a highly schematic view of an internal combustion engine 1, which comprises a number of cylinders 2 and an oil circuit 3. The oil circuit 3 serves in particular to supply lubricating oil to the cylinders 2 of the internal combustion engine 1, which is supplied to the cylinders 2 of the internal combustion engine 1 via a forward section 4 and discharged via a return section 5.

[0018] According to the invention herein, it is proposed to detect a measured value of the total base number (TBN) and / or a measured value of the viscosity of the lubricant currently used in the oil circuit for lubrication 3. The measured value of the total base number of the lubricant currently used in the oil circuit for lubrication 3 is detected using a first sensor 6. The measured value of the viscosity of the lubricant currently used in the oil circuit for lubrication 3 is detected using a second sensor 7.

[0019] The arrangement of the sensors 6 and 7 in the oil circuit is arbitrary. It is also possible to combine the two sensors 6 and 7 into one unit.

[0020] Depending on the established measured value of the total base number and / or depending on the established measured value of the viscosity, the amount of oil to be replaced in the oil circuit 3 is determined. For this purpose, the two sensors 6 and 7 transmit their respective measured values ​​to a control unit 12, which determines the amount of oil to be replaced in the oil circuit 3 depending on the measured value of the total base number and / or depending on the measured value of the viscosity.

[0021] According to the invention, the lubricating oil currently in use is removed from the oil circuit 3 in an amount corresponding to the determined oil change amount, and fresh lubricating oil is supplied to the oil circuit 3 in an amount corresponding to the determined oil change amount. The control unit 12 determines the control variables as a function of which oil change is to be performed.

[0022] Thus, Figure 1 shows a first valve 8 which can be controlled directly or indirectly by a control unit 12, which receives an intermediate connection of a further control unit, in order to remove lubricating oil from the oil circuit 3 in an amount corresponding to the determined oil replacement quantity and collect it in a collection tank 10. Furthermore, Figure 1 shows another valve 9 which can also be controlled from the control unit 12 in order to supply the oil circuit 3 with fresh lubricating oil which is prepared in a storage tank 11.

[0023] Therefore, the present invention proposes removing a defined amount of oil from the oil circuit 3 and replacing it with the same amount of new lubricating oil depending on the measured value of the total base number and / or depending on the measured value of the viscosity of the lubricating oil currently used in the oil circuit 3 for lubrication, i.e., with the degree of oil replacement established as a function of the respective measured values.

[0024] In this way, the consumption of lubricating oil in the region of the cylinder 2 can be reproduced. In order to maintain the lubricating oil properties of the lubricating oil and to make a complete oil change of the internal combustion engine 1 unnecessary, a defined change amount of fresh oil can be continuously supplied.

[0025] Depending on the established measured value of the total base number and / or depending on the established measured value of the viscosity, the determination of the replacement oil quantity for the oil circuit is preferably carried out using a characteristic diagram or characteristic curve, which is stored in the control unit 12. The replacement oil quantities are stored for various support points of the measurement. Interpolation or extrapolation can be carried out between the individual support points.

[0026] This method is used in diesel internal combustion engines or dual-fuel internal combustion engines operated in diesel operating mode. In particular, the amount of oil to be replaced is determined based on two measurements: the total base number of the lubricating oil and the viscosity. This procedure is particularly suitable for diesel internal combustion engines or dual-fuel engines operated in diesel operating mode.

[0027] The present invention further relates to a control unit 12 for carrying out this method. The control unit is equipped to carry out the above-described method on the control side. For this purpose, the control unit 12 comprises a data interface for exchanging data with the assemblies involved in carrying out the method according to the present invention, in particular with the sensors 6 and 7 and the valves 8 and 9. Furthermore, the control unit 12 as a hardware assembly comprises a processor for data processing and a memory for data storage. Furthermore, the control unit 12 comprises software means, which are program modules that serve to carry out the method according to the present invention.

[0028] The control unit 12 receives respective measured values ​​from the respective sensors 6 and 7, preferably a total base number measured value from sensor 6 and a viscosity measured value from sensor 7. The control unit 12 determines the oil change amount depending on the respective measured values. Depending on the oil change amount, the control unit 12 issues control signals and, as a function of these control signals, an oil change is performed, and thus, depending on these control signals, the lubricating oil currently used is removed from the oil circuit 3 and new lubricating oil is supplied to the oil circuit 3.

[0029] The present invention particularly relates to the field of so-called large engines or large internal combustion engines, whose cylinders have piston diameters of more than 140 mm, in particular more than 175 mm. Such large internal combustion engines are, for example, marine engines. In the present invention, these are embodied as diesel internal combustion engines or dual-fuel internal combustion engines operated in diesel operating mode. As fuel, such internal combustion engines burn gaseous fuels such as natural gas or liquid fuels such as methanol. Internal combustion engines that burn gaseous fuels are also called gas engines. [Explanation of symbols]

[0030] 1. Internal combustion engine 2 cylinders 3 Oil circuit 4 Progress section 5 Return Section 6 sensors 7 Sensors 8 valves 9 Valves 10 Collection Tank 11 Storage Tank 12 Control Unit

Claims

1. A method for operating a diesel internal combustion engine (1) or a dual-fuel internal combustion engine (1) operated in diesel operating mode, comprising: The internal combustion engine (1) is operated and lubricating oil is supplied to it via an oil circuit (3), A step in which a measured value of the total base number and / or a measured value of the viscosity of the lubricating oil currently used in the oil circuit (3) for lubrication is detected; Determining the amount of oil to be replaced in the oil circuit (3) depending on the measured value of the detected total base number and / or depending on the measured value of the determined viscosity; a step in which currently used lubricating oil is removed from said oil circuit (3) to an extent corresponding to an oil change quantity; A step of introducing new lubricating oil into the oil circuit (3) in an amount corresponding to the amount of oil to be replaced; the lubricating oil removed from the oil circuit (3) is collected in a collection tank (10) and then disposed of; The amount of oil to be replaced in the oil circuit (3) is determined as a function of a characteristic diagram or characteristic curve depending on the measured value of the detected total base number and / or depending on the measured value of the detected viscosity, A method in which the oil replacement quantities are stored for different support points of total base number and / or viscosity measurements, and interpolation or extrapolation is performed between the individual measurements as needed.

2. The measured values ​​of the total base number and the viscosity of the lubricating oil currently used in the oil circuit (3) for lubrication are detected; 2. The method according to claim 1, characterized in that the amount of oil to be replaced in the oil circuit (3) is determined depending on the measured value of the detected total base number and depending on the measured value of the detected viscosity.

3. 3. The method according to claim 1 or 2, characterized in that a measured value of the total base number of the lubricating oil currently used in the oil circuit (3) for lubrication is detected by means of a first sensor (6).

4. 4. The method according to claim 1, wherein a measurement of the viscosity of the lubricating oil currently used in the oil circuit for lubrication is detected by means of a second sensor.

5. A control unit (12) for operating a diesel internal combustion engine (1) or a dual-fuel internal combustion engine (1) operated in diesel operating mode, comprising: The control unit (12) receives a measurement of the total base number from a sensor (6) and / or a measurement of the viscosity from a sensor (7) of the lubricating oil currently being used to lubricate the internal combustion engine; The control unit (12) determines the amount of oil to be replaced depending on the measured value of the total base number and / or depending on the measured value of the viscosity, The control unit (12) issues a control signal as a function of the amount of lubricating oil currently in use that can be removed from the oil circuit to a degree corresponding to the determined amount of replacement oil to be discarded; The control unit (12) generates a control signal as a function of the amount of fresh lubricating oil that can be supplied to the oil circuit in a manner corresponding to the determined oil replacement amount; The amount of oil to be replaced in the oil circuit (3) is determined as a function of a characteristic diagram or characteristic curve depending on the measured value of the detected total base number and / or depending on the measured value of the detected viscosity, A control unit characterized in that for different support points of measured values ​​of the total base number and / or viscosity, the amount of oil to be replaced is stored and, if necessary, interpolation or extrapolation is performed between the individual measured values.

6. 6. A control unit according to claim 5, characterized in that it is equipped to carry out the method according to any one of claims 1 to 4 on the control side.

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