METHOD AND CONTROL UNIT FOR OPERATING A SPARK-IGNITION INTERNAL COMBUSTION ENGINE OR A DUAL-FUEL INTERNAL COMBUSTION ENGINE OPERATED IN SPARK-IGNITION MODE - Patent application

Abstract

To provide a method for operating a spark ignition type internal combustion engine (1) or a dual fuel type internal combustion engine (1) operated in a spark ignition mode.SOLUTION: Lubrication oil is supplied to an operated internal combustion engine (1) through an oil circuit (3), and a measurement value of a total base number and / or a measurement value of an acid value of lubrication oil that is used at that time in the oil circuit (3) for lubrication are detected. In accordance with the established measurement value of the total base number and / or in accordance with the established measurement value of the acid value, an oil exchange amount in the oil circuit (3) is determined. The lubrication oil used at that time to the extent corresponding to the oil exchange amount is removed from the oil circuit (3), and new lubrication oil to the extent corresponding to the oil exchange amount is applied to the oil circuit (3).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for operating a spark ignition internal combustion engine or a dual fuel internal combustion engine operated in spark ignition mode.The present invention further relates to a control unit for operating a spark ignition internal combustion engine or a dual fuel internal combustion engine operated in spark ignition mode.

[0002] The invention relates here in particular to the field of so-called large engines or large internal combustion engines, whose cylinders are equipped with pistons with a diameter greater than 140 mm, in particular greater than 175 mm. Such large internal combustion engines are, for example, marine engines. [Background technology]

[0003] An internal combustion engine must be lubricated with a lubricating oil during operation. In the process, the lubricating oil undergoes operation-related aging. The aging of the lubricating oil can result in the lubricating oil losing 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 common for some of the lubricating oil to enter the combustion chamber of the cylinder and be burned together with the fuel being combusted. The consumption of lubricating oil in connection with this operation is compensated for and the lubricating oil circuit is constantly supplied with fresh lubricating oil, especially if too much lubricating oil is burned in the region of the cylinder.

[0005] Through the consumption or burning of lubricating oil within the area of ​​the cylinders and the replenishment of fresh lubricating oil to make up for this oil consumption, the correct lubricating effect of the lubricating oil is maintained in most conventional large internal combustion engines, thereby eliminating the need to perform a complete oil change of the internal combustion engine, which involves significant expense.

[0006] However, the burning of lubricating oil in the cylinder area results in the emission of large amounts of exhaust gas. Due to increasingly strict emission regulations, the burning of lubricating oil in the cylinder area must be avoided. In this case, the refilling of burnt lubricating oil, which is carried out in conventional large internal combustion engines, is reduced. In internal combustion engines, therefore, it is necessary to burn as little lubricating oil as possible in the cylinder in order to improve the emission of exhaust gases, and to carry out a complete oil change, especially in the case of excessive aging of the lubricating oil, which is expensive.

[0007] It must therefore be possible in newer types of internal combustion engines, in which lubricating oil is only burned to a small extent in the region of the cylinders, to carry out a complete oil change without it. Summary of the Invention [Problem to be solved by the invention]

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

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

[0010] According to the invention, a measured value of the total base number or a measured value of the acid number of the lubricant currently being used in the oil circuit for lubrication is detected. Depending on the measured value of the total base number and / or depending on the measured value of the acid number, an oil change amount for the oil circuit is determined. The lubricant currently being used is removed from the oil circuit in the range of the determined oil change amount. Furthermore, fresh lubricant is fed to the oil circuit to an extent corresponding to the determined oil change amount. According to the invention, it is proposed for the first time to determine the total base number (TBN) and / or the acid number of the lubricant used by measurement. Depending on the respective detected measured values, an oil change amount for the internal combustion engine is determined. Then, in the range of the oil change amount, the lubricant is specifically removed from the oil circuit and fresh lubricant is fed to the same extent to the lubricant circuit. This allows the lubricant consumption to be regenerated without being affected by exhaust gas emissions. The lubricant removed from the oil circuit can be collected in a collection tank and subsequently disposed of or further used. A complete oil change can therefore be eliminated even in internal combustion engines whose design means that the lubricant is burned in the area of ​​the cylinders.

[0011] According to a further development of the invention, the measured values ​​of the total base number and the acid number of the lubricating oil currently used in the oil circuit for lubrication are detected, and the oil change amount for the oil circuit is determined according to the determined measured values ​​of the total base number and according to the determined measured values ​​of the acid number. Establishing the oil change amount according to both measured values ​​of the lubricating oil, i.e. according to both the total base number and the acid number of the lubricating oil, is particularly suitable for advantageously determining the oil change amount for a spark-ignition internal combustion engine or a dual-fuel internal combustion engine operated in spark-ignition mode.

[0012] According to a further development of the invention, the oil change amount for the oil circuit is determined as a function of the characteristic diagram or characteristic curve as a function of the measured value of the determined total base number and / or as a function of the measured value of the determined acid number. Determining the oil change amount as a function of the characteristic diagram or characteristic curve can be implemented particularly easily. For different support points of the measured values ​​of the total base number and / or acid number, the oil change amounts can be stored and, if necessary, an interpolation between the individual measured values ​​can be carried out.

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

[0014] Advantageous 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 figures, without being limiting thereto. [Brief description of the drawings]

[0015] [Figure 1] The present invention relates to a method and a control unit for operating a spark-ignition internal combustion engine or a dual-fuel internal combustion engine operated in spark-ignition mode. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] 1 shows a highly schematic diagram of an internal combustion engine 1 with a number of cylinders 2 and an oil circuit 3. The oil circuit 3 serves to supply lubricating oil to, in particular, the cylinders 2 of the internal combustion engine 1, which is supplied with lubricating oil via a go side 4 and which leaves the cylinders 2 via a return side 5.

[0017] According to the invention, it is now proposed to determine a measured value of the total base number (TBN) and / or a measured value of the acid number of the lubricant currently being used in the oil circuit for lubrication 3. The measured value of the total base number of the lubricant currently being used in the oil circuit for lubrication 3 is determined with the aid of a first sensor 6. The measured value of the acid number of the lubricant currently being used in the oil circuit for lubrication 3 is determined with the aid of a second sensor 7.

[0018] The arrangement of the sensors 6 and 7 in the oil circuit is variable. It is also possible that the two sensors 6 and 7 are combined in a unit.

[0019] By means of the determined measured value of the total base number and / or by means of the determined measured value of the acid number, an oil change quantity is determined for the oil circuit 3. For this purpose, the two sensors 6, 7 transmit their respective measured values ​​to a control unit 12, which determines the oil change quantity for the oil circuit 3 as a function of the measured value of the total base number and / or as a function of the measured value of the acid number.

[0020] According to the invention, the lubricating oil currently in use is removed from the oil circuit 3 to an extent corresponding to the determined oil change volume and fresh lubricating oil is supplied to the oil circuit 3 to an extent corresponding to the determined oil change volume. The control unit 12 determines the control variables as a function of which oil change is performed.

[0021] Thus, figure 1 shows a first valve 8, which can be directly or indirectly controlled by a control unit 12 influenced by an intermediate connection of a further control unit, in order to remove lubricating oil from the oil circuit 3 to an extent corresponding to a determined replacement amount and to collect the removed oil in a collection tank 10. Furthermore, figure 1 shows a further valve 9, which can also be controlled from the control unit 12 in order to supply the oil circuit 3 with fresh lubricating oil already maintained in a storage tank 11.

[0022] According to the invention it is proposed accordingly to remove a determined amount of oil from the oil circuit 3 depending on the measured total base number and / or on the measured acid number of the lubricating oil currently being used in the oil circuit 3 for the lubricating oil and to replace this oil with new lubricating oil, i.e. to an extent corresponding to the oil change amount established as a function of the respective measured values.

[0023] In this way, oil consumption can be regenerated in the area of ​​the cylinder 2. A determined oil change amount of new oil can be continuously supplied 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.

[0024] The determination of the oil change amount for the oil circuit as a function of the determined measured value of the total base number and / or as a function of the determined measured value of the acid number is preferably performed as a function of a characteristic map or characteristic curve, which is stored in the control unit 12. The oil change amounts are stored for various support points of the measured value. Interpolation or extrapolation can be performed between the individual support points.

[0025] The method is employed in a spark ignition internal combustion engine or a dual fuel internal combustion engine operated in a spark ignition operating mode. In particular, the oil change amount is determined in response to two measurements, namely, a measurement that depends on both the total base number and the acid number of the lubricating oil. The method is particularly suitable for a spark ignition internal combustion engine or a dual fuel internal combustion engine operated in a spark ignition operating mode.

[0026] The invention further relates to a control unit 12 for carrying out the method. The control unit is provided on the control side for carrying out the aforementioned method. 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 invention, in particular with the sensors 6 and 7 and the valves 8 and 9. Furthermore, the control unit 12 as an assembly on the hardware side comprises a processor for data processing and a memory for data storage. Furthermore, the control unit 12 comprises software-side means which are program modules that contribute to carrying out the method according to the invention.

[0027] The control unit 12 receives the individual measured values ​​from the individual sensors 6, 7, preferentially the total base number measured value from sensor 6 and the acid number measured value from sensor 7. In response to the individual measured values ​​the control unit 12 determines the amount of oil change. In response to the amount of oil change the control unit 12 emits a control signal according to which an oil change occurs, whereby the currently used lubricating oil is removed from the oil circuit 3 and new lubricating oil is supplied to the oil circuit 2, accordingly.

[0028] The invention particularly relates to the field of so-called large engines or large internal combustion engines, whose cylinders are equipped with pistons with a diameter 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 implemented as spark-ignition internal combustion engines or dual-fuel internal combustion engines operated in spark-ignition mode. As fuel, such internal combustion engines burn gaseous fuels such as natural gas or liquid fuels such as methanol. Internal combustion engines burning gaseous fuels are also referred to as gas engines. [Explanation of symbols]

[0029] 1. Internal combustion engine 2 Cylinder 3. Oil circuit 4. Going side 5 Return side 6 Sensors 7. Sensors 8 Valves 9 Valves 10 Collection tank 11 Storage tank 12 Control unit

Claims

1. 1. A method for operating a spark ignition internal combustion engine (1) or a dual fuel internal combustion engine (1) operated in a spark ignition mode, comprising the steps of: The internal combustion engine (1) is operated and lubricating oil is supplied through an oil circuit (3); A measured value of the total base number and / or the acid number of the lubricating oil currently being used in the oil circuit (3) for lubrication is detected; An oil change amount for the oil circuit (3) is determined in response to the determined measured value of the total base number and / or in response to the determined measured value of the acid number, The lubricating oil currently being used is removed from the oil circuit (3) to an extent equivalent to the amount of oil change. A new amount of lubricating oil is applied to the oil circuit (3) in an amount corresponding to the oil change amount. The lubricating oil removed from the oil circuit (3) is collected in a collection tank (10) and subsequently disposed of; the oil change amount for the oil circuit (3) is determined in response to the determined measured value of the total base number as a function of a characteristic map or characteristic curve and / or in response to the determined measured value of the acid number, A method in which the oil change quantities are stored for various support points of the measurement, and an interpolation or extrapolation is performed between the individual support points.

2. The measured value of the total base number and the measured value of the acid number of the lubricating oil currently being used in the oil circuit (3) for lubrication are detected; 2. The method according to claim 1, wherein the oil change amount for the oil circuit (3) is determined in response to the measured value of the determined total base number and in response to the measured value of the determined acid number.

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

4. 4. The method according to claim 1, wherein the measured value of the acid number of the lubricant currently being used in the oil circuit (3) for lubrication is detected with the aid of a second sensor (7).

5. A control unit (12) for operating a spark ignition internal combustion engine (1) or a dual fuel internal combustion engine (1) operated in a spark ignition operating mode, comprising: the control unit (12) receiving a measurement of the total base number from the sensor (6) and / or a measurement of the acid number from the sensor (7) of the lubricating oil currently being used to lubricate the internal combustion engine; The control unit (12) determines an oil change amount depending on the measured value of the total base number and / or depending on the measured value of the acid number, the control unit (12) issues a control signal as a function of the amount of lubricating oil currently in use that is removable for disposal from the oil circuit to an extent that corresponds to the determined amount of oil change that is removable; the control unit (12) transmits a control signal as a function of the amount of fresh lubricant available to the oil circuit corresponding to the determined oil change amount; the oil change amount for the oil circuit (3) is determined in response to the determined measured value of the total base number as a function of a characteristic map or characteristic curve and / or in response to the determined measured value of the acid number, A control unit (12) in which the oil change quantities are stored for various support points of the measurement, and an interpolation or extrapolation is carried out between the individual support points.

6. A control unit according to claim 5, wherein the control unit is equipped to carry out a control side method according to any one of claims 1 to 4.

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