CONDITION BASED OIL MANAGEMENT

Abstract

Method for monitoring a lubricant of a combustion engine, wherein measured numerical values are acquired with at least one sensor over a running time of a combustion engine, wherein the measured numerical values are representative of an oil quality of an engine oil of the combustion engine, wherein an oil sampling interval is adapted depending on at least one measured numerical value and/or a variable derived therefrom.

Claims

1. A method for monitoring a lubricant of a combustion engine, comprising: acquiring a plurality of measured numerical values with at least one sensor over a running time of a combustion engine, wherein the measured numerical values are representative of an oil quality of an engine oil of the combustion engine; and adapting an oil sampling interval depending on at least one measured numerical value of the plurality of measured numerical values and/or a variable derived therefrom.

2. The method of claim 1, comprising deriving an absolute value of the oil quality from the at least one measured numerical value, wherein the absolute value is used for adapting the oil sampling interval.

3. The method of claim 1, wherein the plurality of measured numerical values determined at time intervals and/or variables derived therefrom are used for adapting the oil sampling interval.

4. The method of claim 1, comprising determining a rate of change of at least two successive measured numerical values of the plurality of measured numerical values at a time interval and/or variables derived therefrom.

5. The method of claim 4, wherein the oil sampling interval is adapted depending on the rate of change.

6. The method of claim 1, comprising evening out at least two measured numerical values of the plurality of measured numerical values measured at a particular time interval and/or variables derived therefrom, for adapting the oil sampling interval.

7. The method of claim 1, comprising determining at least two measured numerical values of the plurality of measured numerical values and/or variables derived therefrom by the at least one sensor at prespecified points in time at time intervals prespecified relative to each other and/or in defined operating conditions of the combustion engine.

8. The method of claim 1, wherein the plurality of measured numerical values and/or variables derived therefrom are acquired with a measurement frequency in a range between 0.5 Hz and 3 Hz.

9. The method of claim 1, wherein an electrochemical state variable, comprising electrical conductivity and/or permittivity, of the engine oil is measured by the at least one sensor, wherein the electrochemical state variable represents the at least one measured numerical value of the oil quality of the engine oil.

10. The method of claim 1, comprising: comparing the plurality of measured numerical values and/or the variables derived therefrom with a defined condition, and if the plurality of measured numerical values do not correspond to the condition, then the oil sampling interval is adapted.

11. The method of claim 10, comprising determining, via the condition, an ageing rate for the engine oil under normal conditions and/or in tests in dependence on operating hours of the combustion engine.

12. The method of claim 1, comprising outputting the oil sampling interval as a notification, and outputting a change in the oil sampling interval as a warning.

13. A combustion engine, comprising: at least one oil circuit configured to transport the engine oil for lubricating and/or cooling the combustion engine; the at least one sensor; and a controller configured to receive the at least one measured numerical value, wherein the controller is configured to monitor the oil quality of the engine oil and adapt the oil sampling interval depending on the at least one measured numerical value of the plurality of measured numerical values and/or the variable derived therefrom according to the method of claim 1.

14. A tangible, computer-readable medium storing instructions executable to perform the method according to claim 1.

15. A system, comprising: a controller configured to: acquire a plurality of measured numerical values with at least one sensor over a running time of a combustion engine, wherein the measured numerical values are representative of an oil quality of an engine oil of the combustion engine; and adapt an oil sampling interval depending on at least one measured numerical value of the plurality of measured numerical values and/or a variable derived therefrom.

16. The system of claim 15, comprising an oil circuit configured to circulate the engine oil, wherein the oil circuit comprises the at least one sensor.

17. The system of claim 16, wherein the oil circuit comprises an oil cooler and an oil filter, and the at least one sensor is disposed between the oil cooler and the oil filter.

18. The system of claim 15, comprising the combustion engine having the controller.

19. A system, comprising: a combustion engine having an oil circuit and at least one sensor along the oil circuit; a controller configured to: monitor the at least one sensor to obtain sensor feedback; and adapt an oil sampling interval based on the sensor feedback or a variable derived therefrom.

20. The system of claim 19, wherein the controller is configured to adapt the oil sampling interval at least by changing the oil sampling interval based on a comparison between a defined condition and the sensor feedback or the variable derived therefrom.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0101] Further advantages and details of the invention are revealed by the figures and the associated description of the figures. There are shown in:

[0102] FIG. 1 illustrates an embodiment example of a combustion engine,

[0103] FIG. 2 illustrates an embodiment example of an oil circuit of a combustion engine, and

[0104] FIG. 3 illustrates an embodiment example of a method according to the invention for monitoring the condition of a lubricant of a combustion engine.

DETAILED DESCRIPTION

[0105] FIG. 1 shows a schematic representation of a first embodiment example of a combustion engine 1, wherein the material flows of the combustion engine 1 are illustrated.

[0106] This embodiment variant is a stationary, gas-operated combustion engine 1.

[0107] Thus, first of all, air 3 and a fuel 4 (preferably methane and/or hydrogen) are supplied to a gas mixing device 2, wherein via the gas mixing device 2 an air-fuel mixture is produced and is fed into a supply line 5 of the combustion engine 1.

[0108] This air-fuel mixture is then compressed via a compressor 6 of an exhaust gas turbocharger 7 and cooled by means of a charge air cooler 8.

[0109] The compressor 6 can be bypassed by a bypass line 10 having a bypass valve 9, wherein, to control or regulate a boost pressure (and thus indirectly a power and/or a rotational speed of the combustion engine 1) in a known manner, an air-fuel mixture, which bypasses the compressor 6 via the bypass line 10 from the high-pressure side in the direction of the low-pressure side of the compressor 6, can be controlled or regulated by the bypass valve 9.

[0110] The cooled, compressed air-fuel mixture (represented here by way of example with combustion chambers 11 of the combustion engine 1) is then supplied.

[0111] Arranged between the charge air cooler 8 and the combustion chambers 11 in the supply line 5 is a throttle valve 12, which is formed to control or regulate the boost pressure of the combustion engine 1 by influencing the flow volume.

[0112] In these combustion chambers 11, the air-fuel mixture is compressed, combusted and expanded, wherein the thermal energy released is converted into mechanical energy.

[0113] After the combustion, the exhaust gases which are formed in the combustion and which are utilized to drive an exhaust gas turbine 14, mechanically coupled to the compressor 6, of the exhaust gas turbocharger 7 are discharged via an exhaust gas line 13.

[0114] After passing through the exhaust gas turbocharger 7, the exhaust gas can then also be supplied to an exhaust gas aftertreatment device 15, which can be formed, for example, as a three-way catalytic converter, a selective catalytic reduction (SCR) catalytic converter or also as a heat exchanger for the recovery of heat.

[0115] FIG. 2 shows an embodiment example of an oil circuit 16 of a combustion engine 1, for example, such as the combustion engine 1 represented in FIG. 1.

[0116] This oil circuit 16 of the combustion engine 1 is represented schematically, wherein the arrows on the one hand indicate the flow direction of the engine oil in the oil circuit 16 and on the other hand symbolize the fluidic connection between the components, for example through an oil line.

[0117] The engine oil is conveyed from an oil pan 21 of the combustion engine 1, in which the engine oil collects, via an oil pump 20 to an oil cooler 19, which is provided to control the temperature of or cool the engine oil.

[0118] From the oil cooler 19, the engine oil passes to an oil filter 18, through which suspended matter and particles are filtered out of the engine oil, before the engine oil then enters a crankcase 17 of the combustion engine 1, in order there to serve to lubricate and/or cool the combustion engine 1 during the combustion process.

[0119] After the engine oil has been used, it collects in the oil pan 21 again, whereby the oil circuit 16 of the combustion engine 1 is closed.

[0120] The individual components of the oil circuit 16 (crankcase 17, oil filter 18, oil cooler 19, oil pump 20 and oil pan 21) are for example physically connected by a machine frame of the combustion engine 1.

[0121] Located between the oil filter 18 and the oil cooler 19 is a sensor 23, which is formed to provide at least one measured numerical value 28 representative of the oil quality of the engine oil, which measured numerical value 28 can be provided to the control or regulating device 22 (e.g., a controller) via a signal-carrying connection (represented by the dashed line).

[0122] The sensor 23 is formed here as a sensor which, via the electrical conductivity and/or permittivity of the engine oil, provides the measured numerical value 28 which is indicative of the oil quality of the engine oil. Such a sensor 23 can, for example, be implemented according to known embodiment variants of the state of the art.

[0123] The control or regulating device 22 of this embodiment example is formed to receive the measured numerical value 28 of the sensor 23 and to transform it into an absolute value 27. The absolute value 27 can, for example, reflect an oil quality of the engine oil via a percentage (0-100%).

[0124] This derived variable of the measured numerical value 28 (the absolute value 27) is compared with a condition 24 stored in the control or regulating device 22, whereinif the measured value 28 of the sensor 23 fulfils the condition 24the measurement is continued and, if the measured value 28 of the sensor 23 does not fulfil the condition 24, an oil sampling interval is adapted depending on at least one measured numerical value 28 and/or the absolute value 27.

[0125] The oil sampling interval is output in the form of a notification 31.

[0126] This outputting of the notification 31 by the control or regulating device 22 can be performed via a display device of the control or regulating device 22.

[0127] FIG. 3 shows an embodiment example according to the method according to the invention for monitoring the condition of a lubricant of the combustion engine 1 graphically.

[0128] This graph shows the relationship of measured values 28 of the sensor 23 with respect to operating hours 29 of the combustion engine 1 and what condition 24 can be stored in the control or regulating device 22.

[0129] Reference values 30 were determined via tests and simulations, which represent the acceptable ageing of an engine oil with regard to the operating hours 29 performed by the combustion engine 1.

[0130] These reference values 30 were entered in a graph, which represents the measured values 28, characteristic of the oil quality, of the sensor 23 through the variable of the absolute value 27 derived therefrom over the operating hours 29.

[0131] As can be seen, the measured numerical value 28 of the sensor 23 (which ranges between a value of 0 and 1) has been converted into a derived variablethe absolute value 27 of an oil quality of the engine oil (decreasing in the opposite direction from 100% to 0%).

[0132] Furthermore, it was defined thatif the absolute value 27 of the oil quality drops below a region of 40%the taking of an oil sample of engine oil from the combustion engine 1 is called for immediately.

[0133] As can be seen, the reference values 30 of normal ageing with regard to the operating hours 29 of the combustion engine 1 form an approximately linear function.

[0134] The condition 24, which represents a range, was defined through this linear function.

[0135] In the case of the condition 24, possible deviations of the measured values 28 because of measuring inaccuracies as well as an acceptable variation in the oil quality were also taken into account.

[0136] This results in the condition 24, which is assigned a minimum and maximum of the permissible oil quality for each number of operating hours 29.

[0137] If, in the ongoing operation of the combustion engine 1, a measured numerical value 28 which does not fulfil the condition 24 because it exceeds a lower limit of the oil quality defined by the condition 24 is now ascertained via the sensor 23, a corresponding notification 31 in the form of an adaptation of the oil sampling interval is output by the control or regulating device 22.

[0138] This is based on the fact that such a measured numerical value 28 of the sensor 23 indicates a change in the oil quality not to be expected, as a result of which it is necessary to undertake more precise investigations by taking an oil sample of engine oil from the combustion engine 1 and forwarding it to a laboratory for detailed analysis, wherein, on the basis of the laboratory values of the engine oil, a decision can then be taken on how to proceed further with the engine oil (change or further operation of the combustion engine 1).

[0139] If, however, the oil quality 24 decreases rapidly with regard to a defined number of operating hours 29, a tolerance range 25 can also be provided, wherein, when this tolerance range 25 is exceeded, a critical notification 26 can be output by the control or regulating device 22.

[0140] Such a critical notification 26 by the control or regulating device 22 can, for example, result in the shutdown of the combustion engine 1 or the restriction (for example, of a power output) of the combustion engine 1.

[0141] The reason behind this is that such a rapid deterioration of the engine oil is not to be attributed to the normal operation of the combustion engine 1, wherein in all probability the reason behind this rapid decrease in the engine oil quality is damage to the combustion engine 1, due to which the operation of the combustion engine 1 is to be ceased immediately in order to prevent even further subsequent greater damage.

LIST OF REFERENCE NUMBERS

[0142] 1 combustion engine [0143] 2 gas mixing device [0144] 3 air [0145] 4 fuel [0146] 5 supply line [0147] 6 compressor [0148] 7 exhaust gas turbocharger [0149] 8 charge air cooler [0150] 9 bypass valve [0151] 10 bypass line [0152] 11 combustion chamber [0153] 12 throttle valve [0154] 13 exhaust gas line [0155] 14 exhaust gas turbine [0156] exhaust gas aftertreatment device [0157] 16 oil circuit [0158] 17 crankcase [0159] 18 oil filter [0160] 19 oil cooler [0161] 20 oil pump [0162] 21 oil pan [0163] 22 control or regulating device [0164] 23 sensor [0165] 24 condition [0166] 25 tolerance range [0167] 26 critical notification [0168] 27 absolute value [0169] 28 measured value [0170] 29 operating hours [0171] 30 reference values [0172] 31 notification