Evaluation device and evaluation method

Abstract

This evaluation device comprises: an acquisition unit that acquires an observed value of an observable parameter that has a correlation with the rotating pressure vessel oxidation test (RPVOT) residual ratio and that represents the properties of a lubricating oil; a calculation unit that calculates an estimated value of the RPVOT residual ratio corresponding to the observed value on the basis of the correlation; and an output unit that outputs an evaluation result pertaining to the degree of deterioration of the lubricating oil on the basis of the estimated value.

Description

Evaluation device and evaluation method

[0001] This application claims priority to Japanese Patent Application No. 2024-078397, filed May 14, 2024, the contents of which are incorporated herein by reference.

[0002] In Patent Document 1, a diagnostic method for easily determining the formation of sludge and varnish in oil is disclosed, in which a first threshold value, which is a threshold value of the total acid number for controlling the amount of sludge and varnish formed, is set based on information showing the relationship between a first result, which is a result of measuring the total acid number of the lubricating oil, and a second result, which is a result of measuring the amount of sludge and varnish formed in the lubricating oil. Furthermore, in this diagnostic method, a second threshold value, which is a threshold value of the optical measurement result for controlling the amount of sludge and varnish formed, is set based on information showing the relationship between the first result and a third result, which is a result of optical measurement of the lubricating oil.

[0003] Japanese Patent Application Laid-Open No. 2023-013358

[0004] As described above, the diagnostic method described in Patent Document 1 diagnoses the acid value of a lubricating oil and the amount of sludge and varnish produced in the oil by comparing the lubricating oil color information obtained by an optical sensor with the acid value measurement value and the amount of sludge and varnish produced in advance. However, because the increase in acid value of turbine oil, for example, does not change linearly from the value of new oil, there are cases where it is not possible to appropriately set the threshold value used for evaluation, which has been a problem in that it is sometimes not possible to appropriately evaluate the degree of deterioration of the lubricating oil.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide an evaluation device and an evaluation method that can appropriately evaluate the degree of deterioration of a lubricating oil.

[0006] In order to solve the above problem, the evaluation device according to the present disclosure includes an acquisition unit that acquires an observed value of an observable parameter that is correlated with a Rotating Pressure Vessel Oxidation Test (RPVOT) remaining rate and that represents the properties of the lubricant, a calculation unit that calculates an estimated value of the RPVOT remaining rate that corresponds to the observed value based on the correlation, and an output unit that outputs an evaluation result regarding the degree of deterioration of the lubricant based on the estimated value.

[0007] In addition, the evaluation device according to the present disclosure is equipped with an acquisition unit that acquires an observed value of an observable parameter that is correlated with acid value and represents the properties of the lubricant, a calculation unit that calculates an estimated value of the acid value corresponding to the observed value based on the correlation, and an output unit that outputs an evaluation result regarding the degree of deterioration of the lubricant based on the estimated value, wherein the parameter is the difference between the measured value of the dielectric constant or relative permittivity of the lubricant and the new oil value of the dielectric constant or relative permittivity of the lubricant, divided by the new oil value.

[0008] In addition, the evaluation device according to the present disclosure includes an acquisition unit that acquires an observed value of an observable parameter that is correlated with the acid number and represents the properties of the lubricant, a calculation unit that calculates an estimated value of the acid number corresponding to the observed value based on the correlation, and an output unit that outputs an evaluation result regarding the degree of deterioration of the lubricant based on the estimated value, wherein the parameter is the amount of change per unit time in the dielectric constant or relative dielectric constant of the lubricant.

[0009] In addition, the evaluation method according to the present disclosure includes the steps of: acquiring an observed value of an observable parameter that is correlated with the RPVOT residual rate and that represents the properties of the lubricant; calculating an estimated value of the RPVOT residual rate that corresponds to the observed value based on the correlation; and outputting an evaluation result regarding the degree of deterioration of the lubricant based on the estimated value.

[0010] In addition, the evaluation method according to the present disclosure includes the steps of acquiring an observed value of an observable parameter that is correlated with acid number and represents the properties of the lubricant, calculating an estimated value of the acid number corresponding to the observed value based on the correlation, and outputting an evaluation result regarding the degree of deterioration of the lubricant based on the estimated value, wherein the parameter is the difference between the measured value of the dielectric constant or relative permittivity of the lubricant and the new oil value of the dielectric constant or relative permittivity of the lubricant, divided by the new oil value.

[0011] In addition, the evaluation method according to the present disclosure includes the steps of: acquiring an observed value of an observable parameter that is correlated with acid number and represents the properties of the lubricant; calculating an estimated value of the acid number corresponding to the observed value based on the correlation; and outputting an evaluation result regarding the degree of deterioration of the lubricant based on the estimated value, wherein the parameter is the amount of change per unit time in the dielectric constant or relative dielectric constant of the lubricant.

[0012] According to the evaluation device and evaluation method of the present disclosure, the degree of deterioration of a lubricating oil can be appropriately evaluated.

[0013] 1 is a block diagram illustrating an example configuration of an evaluation device and an evaluation system according to an embodiment of the present disclosure. FIG. 2 is a schematic diagram illustrating an example configuration of an evaluation system according to an embodiment of the present disclosure. FIG. 3 is a flowchart illustrating an example diagnostic flow for oil state monitoring using multiple in-line sensors according to an embodiment of the present disclosure. FIG. 4 is a diagram illustrating an example relationship between color (e.g., G) and RPVOT residual rate according to an embodiment of the present disclosure. FIG. 5 is a flowchart illustrating an example flow for evaluating RPVOT residual rate using a color sensor according to an embodiment of the present disclosure. FIG. 6 is a diagram illustrating an example relationship between dielectric constant and RPVOT residual rate (at constant oil temperature) according to an embodiment of the present disclosure. FIG. 7 is a diagram illustrating an example relationship between temperature-corrected and moisture-corrected dielectric constant and RPVOT residual rate according to an embodiment of the present disclosure. FIG. 8 is a flowchart illustrating an example flow for evaluating RPVOT residual rate using a dielectric sensor according to an embodiment of the present disclosure. FIG. 9 is a diagram illustrating an example relationship between color (G) and an acid number within the control standard according to an embodiment of the present disclosure. FIG. 10 is a flowchart illustrating an example flow for evaluating acid number using a color sensor according to an embodiment of the present disclosure. FIG. 11 is a diagram illustrating an example relationship between RPVOT residual rate and acid number (in the case of turbine oil) according to an embodiment of the present disclosure. FIG. 12 is a diagram illustrating an example relationship between relative dielectric constant (at constant or corrected oil temperature) and acid number according to an embodiment of the present disclosure. FIG. 1 is a diagram showing an example of the relationship between the relative dielectric constant (at constant or corrected oil temperature) and the acid number within the control standard according to an embodiment of the present disclosure. FIG. 2 is a diagram showing an example of the relationship between the rate of change in relative dielectric constant and the acid number according to an embodiment of the present disclosure. FIG. 3 is a flowchart showing an example of the flow of acid number evaluation using a dielectric sensor according to an embodiment of the present disclosure. FIG. 4 is a diagram showing an example of the relationship between the amount of change in relative dielectric constant per unit time and the acid number according to an embodiment of the present disclosure. FIG. 5 is a flowchart showing another example of the flow of acid number evaluation using a dielectric sensor according to an embodiment of the present disclosure. FIG. 6 is a diagram showing an example of how oil is displayed after diagnosis of its condition according to an embodiment of the present disclosure. FIG. 7 is a diagram showing an example of how oil degradation is estimated and an abnormality diagnosis is determined using a color sensor and a dielectric sensor according to an embodiment of the present disclosure. FIG. 8 is a schematic block diagram showing the configuration of a computer according to an embodiment of the present disclosure.

[0014] Hereinafter, an evaluation device and an evaluation method according to an embodiment of the present disclosure will be described with reference to the drawings. Note that the same or corresponding components in the drawings are designated by the same reference numerals and their description will be omitted as appropriate.

[0015] (Configuration example of evaluation device and evaluation system) Fig. 1 is a block diagram showing a configuration example of an evaluation device and an evaluation system according to an embodiment of the present disclosure. Fig. 2 is a schematic diagram showing a configuration example of an evaluation system according to an embodiment of the present disclosure.

[0016] 1 , an evaluation system 100 according to an embodiment of the present disclosure includes an evaluation device 1, a sensor group 2, one or more user terminals 3, and a heating unit 4. The sensor group 2 includes, for example, a color sensor 21, a dielectric constant sensor 22, a moisture sensor 23, a temperature sensor 24, a contamination sensor 25, a differential pressure sensor 26, a viscosity sensor 27, and a density sensor 28. The sensor group 2 may include other types of sensors.

[0017] The sensor group 2 (sensor group 2a and sensor group 2b) detects various properties of lubricating oil 109 supplied to bearings 104 to 107 provided on a rotating shaft 103 in a power generation plant including a gas turbine 101 and a generator 102, as shown in FIG. 2 . In the example shown in FIG. 2 , the sensor group 2a is provided in a tank (oil tank) 108 for the lubricating oil 109. The sensor group 2b is provided midway along an outward pipe 113 connecting the tank 108 and an oil washer 112. A pipe 114 forms a return path for the lubricating oil 109 from the oil washer 112 to the tank 108. A pipe 110 forms a forward path for the lubricating oil 109 supplied from the tank 108 to the bearings 104 to 107. A pipe 111 forms a return path for the lubricating oil 109 from the bearings 104 to 107 to the tank 108. The tank 108 and the pipes 110, 111, 113, and 114 are provided with one or more hydraulic pumps (not shown). The tank 108 is provided with a heater, and the oil washer 112 is provided with a moisture remover. The heater and the moisture remover correspond to the heating unit 4 shown in FIG. 1. The heating unit 4 increases the temperature of the lubricating oil 109 based on an instruction from the evaluation device 1, and evaporates free water contained in the lubricating oil 109, for example.

[0018] The color sensor 21 uses an LED (light-emitting diode) light as a light source, and detects the amount of light transmitted through the lubricating oil 109 at its light-receiving section. It outputs values ​​(e.g., values ​​from 0 to 255) representing each of the RGB color components (red, green, and blue components), which represent the color of the transmitted light, as well as information representing the color difference ΔE (= (R2+G2+B2)1 / 2). The color sensor sets the value for new oil as (R, G, B) = (255, 255, 255), and outputs values ​​that decrease from 255 as the oil deteriorates and becomes discolored. The color sensor 21 may also output other values, such as maximum color difference = (maximum value of R, G, B) - (minimum value of R, G, B).

[0019] The dielectric constant sensor 22 measures the dielectric constant and relative dielectric constant of the lubricating oil 109 and outputs the measurement results. In the present disclosure, in each drawing, for example, a characteristic diagram uses relative dielectric constant, and for example, a flowchart uses dielectric constant, but the dielectric constant and relative dielectric constant can be interpreted interchangeably and are used as equivalent values.

[0020] The water sensor 23 detects the water activity (Aw) value of the lubricating oil 109. The water sensor 23 can measure aw, which is the ratio of the amount of water to the saturated amount of water, or % RH (relative amount). The water activity value is a value between 0 and 1, where 1 is the maximum amount of water that can be contained in the oil, i.e., the saturated amount of water. When the water activity value reaches 1 (aw), water appears in the oil, causing it to become cloudy.

[0021] The temperature sensor 24 detects the temperature of the lubricating oil 109. The contaminant sensor 25 detects the amount of contaminants contained in the lubricating oil 109 and outputs information indicating the detection result (such as ISO (International Organization for Standardization) grade, NAS (National Aeronautics and Space Standards) grade, or SAE (Society of Automotive Engineers) grade). The differential pressure sensor 26 detects the differential pressure of a filter provided in the oil washer 112 or the like and outputs the detection result. The viscosity sensor 27 detects the viscosity of the lubricating oil 109 and outputs the detection result. The density sensor 28 detects the density of the lubricating oil 109 and outputs the detection result.

[0022] The sensors included in the sensor group 2 (2 a, 2 b) may be configured as a single unit. For example, the temperature sensor 24 and the dielectric constant sensor 22 may be configured as a single unit.

[0023] In order to obtain stable measurement data by performing sensor measurements in a location where the temperature and oil condition are uniform, the following are preferable conditions for the installation location of the various sensors used in diagnosis: (1) The detection part of the sensor is immersed in the oil. (2) Locations where a large number of air bubbles exist in the oil should be avoided. (3) A location where the temperature is stable. (4) A location where the oil is replaced. (5) There should be no large leakage of oil when the sensor is replaced. (6) There should be no severe vibration at the sensor mounting location.

[0024] For example, in the lubrication oil system of a power generation turbine plant, the turbine bearing oil drain line should be avoided because it contains a lot of bubbles. The turbine bearing oil supply line should also be avoided because it would be problematic if the sensor parts were to enter the turbine in the event of a physical failure of the sensor. However, possible countermeasures include installing a foam suppressor in the oil drain line or a filter in the oil supply line that can capture any oil that leaks if the sensor part is damaged. When installing inside an oil tank, it is best to locate the sensor in a location where the oil is replaced. Examples of sensor installation locations include inside the oil tank or in the piping line to ancillary equipment (such as an oil washer).

[0025] The evaluation device 1 can be configured using a computer such as a personal computer (hereinafter also referred to as a PC), a logger, etc. The evaluation device 1 includes functional blocks configured by a combination of hardware and software, such as an acquisition unit 11, a calculation unit 12, a log information storage unit 13, a correlation information storage unit 14, an input unit 15, an output unit 16, and a communication unit 17.

[0026] The acquisition unit 11 acquires at least one of the observed values ​​of an observable parameter that is correlated with the RPVOT residual rate and represents the properties of the lubricant, and the observed values ​​of an observable parameter that is correlated with the acid number and represents the properties of the lubricant. Here, the observable parameter that represents the properties of the lubricant is, for example, the color or color difference of the lubricant 109, or the dielectric constant or relative permittivity of the lubricant 109. Alternatively, the parameter may be, for example, the difference between the measured value of the dielectric constant or relative permittivity of the lubricant and the new oil value of the dielectric constant or relative permittivity of the lubricant divided by the new oil value, or the amount of change per unit time in the dielectric constant or relative permittivity of the lubricant (details will be described later). The observed value may be, for example, the output value of the color sensor 21 or the output value of the dielectric constant sensor 22, or a predetermined calculated value based on these output values.

[0027] The calculation unit 12 calculates an estimated value of the RPVOT residual rate corresponding to the observed value based on the correlation between the RPVOT residual rate and the above parameter, or calculates an estimated value of the acid number corresponding to the observed value based on the correlation between the acid number and the above parameter. Note that, when the parameter is the dielectric constant or relative permittivity of the lubricant, the calculation unit 12 may calculate an estimated value of the RPVOT residual rate corresponding to a value obtained by correcting the observed value based on the water activity value and temperature of the lubricant based on the correlation between the RPVOT residual rate and the parameter. Note that, when the parameter is the dielectric constant or relative permittivity of the lubricant, the calculation unit 12 may calculate an estimated value of the acid number corresponding to a value obtained by correcting the observed value based on the water activity value and temperature of the lubricant based on the correlation between the acid number and the parameter.

[0028] The log information storage unit 13 records the detection signals of the various sensors received from the sensor group 2 in association with time information and the like.

[0029] The correlation information storage unit 14 stores information indicating the correlation between the RPVOT residual rate and observable parameters that represent the properties of the lubricating oil, information indicating the correlation between the acid value and observable parameters that represent the properties of the lubricating oil, and information indicating control values ​​and various thresholds for the RPVOT residual rate, acid value, etc. The RPVOT residual rate is the value obtained by dividing the RPVOT value of a deteriorated oil by the RPVOT value of a new oil. The RPVOT value is an index of the degree of deterioration, for example, the time required for the pressure inside a pressure vessel containing a certain amount of sample and oxygen to drop to a specified pressure when the vessel is heated while rotating under conditions specified in JIS (Japanese Industrial Standards) K2514-3. The acid value is, for example, the number of milligrams of potassium hydroxide required to neutralize 1 g of sample under conditions specified in JIS (Japanese Industrial Standards) K2501.

[0030] The input unit 15 includes, for example, an input interface, an input device, etc., and inputs predetermined information from the outside.

[0031] The output unit 16 includes, for example, an output interface, an output device, etc., and outputs predetermined information to the outside. In this embodiment, the output unit 16 outputs an evaluation result regarding the degree of deterioration of the lubricant based on the estimated value calculated by the calculation unit 12. The output unit 16 outputs the evaluation result to an output device such as a display device, or to the user terminal 3 via the communication unit 17. The evaluation result regarding the degree of deterioration of the lubricant may be, for example, an estimated RPVOT remaining rate, an estimated acid value, a predetermined index value indicating the degree of deterioration based on each estimated value, information indicating the need for replacement or preparation for replacement, etc. Note that the output unit 16 may output the evaluation result when the water activity value of the lubricant is within a predetermined range, and not output the evaluation result when the water activity value of the lubricant is not within the predetermined range (or may output information indicating that the water activity value of the lubricant is not within the predetermined range). In addition, when the above parameter is the green component or the blue component or the color difference when the color of the lubricating oil is expressed using three color components, namely, red, green, and blue, the output unit 16 may output the evaluation result when the red component is within a predetermined range, and may not output the evaluation result (or output information indicating that the red component is not within the predetermined range) when the red component is not within the predetermined range.

[0032] The communication unit 17 transmits and receives predetermined information to and from the sensor group 2, the user terminal 3, the heating unit 4, and the like.

[0033] The terminal 3 is, for example, a computer such as a personal computer, smartphone, or tablet terminal, and is equipped with a display unit 31, a communication unit 32, etc., and accesses the evaluation device 1 and outputs (displays, etc.) information such as evaluation results regarding the degree of deterioration of the lubricating oil sent from the evaluation device 1.

[0034] (Example of Operation of Evaluation System) Fig. 3 is a flowchart showing an example of a diagnostic flow for oil state monitoring using multiple in-line sensors by the evaluation system 100 according to an embodiment of the present disclosure. The process shown in Fig. 3 is executed repeatedly at a predetermined cycle, for example.

[0035] The evaluation system 100 estimates the RPVOT residual rate and acid number, which are indicators of oil degradation, based on sensor measurement values, and monitors the condition of the oil. The evaluation system 100 monitors the condition of the oil using multiple sensors included in the sensor group 2. The evaluation system 100 measures viscosity, density, dielectric constant, color (R, G, B, ΔE, color difference), moisture content (also known as water activity value), and contamination amount, etc. Because the sensor measurement values ​​contain various information, multiple sensors are combined to closely examine the information for oil condition monitoring. For example, to measure the RPVOT residual rate, the moisture content, contamination amount, and temperature can be confirmed based on the measurement values ​​of color and dielectric constant.

[0036] The evaluation device 1 receives analog or CAN (Controller Area Network) signals from the multiple sensors included in the sensor group 2, processes the signals using a logger or PC, calculates the measured values, performs correction processing, diagnoses and determines abnormalities, and stores and displays the necessary information. After diagnosing the oil condition, the evaluation result values ​​regarding the degree of deterioration of the lubricating oil can be displayed to the customer (terminal 3) using the following examples.

[0037] (1) Indicates the degree of condition, with the higher the number, the more advanced the oil degradation. Abnormalities other than oil degradation are also expressed numerically. Alarms are issued for abnormalities in oil degradation and abnormalities due to moisture or foreign matter contamination (Fig. 18). (2) Roughly indicates the numerical value (%) of the RPVOT remaining rate. Abnormalities due to moisture or foreign matter contamination are also displayed separately. Alarms are issued for abnormalities in oil degradation and abnormalities due to moisture or foreign matter contamination (Fig. 19). Executes a diagnostic flow for oil condition monitoring using multiple in-line sensors (Figs. 3 and 20).

[0038] 3, the evaluation device 1 first acquires information indicating detection results from the multiple sensors of the sensor group 2 (step S11). Next, the evaluation device 1 checks for viscosity abnormalities (step S12). The viscosity information is obtained from the measured value of the viscosity sensor 27. For example, the viscosity control standard value for turbine lubricating oil is set to ±5% of the new oil value. Possible causes of the abnormal viscosity value include mixing with other oils. If the viscosity value is abnormal (step S12: No), the evaluation device 1 prompts the user to perform an oil analysis or oil change to determine the cause (step S13).

[0039] Next, the evaluation device 1 checks for moisture abnormalities (step S14). In step S14, information on the water activity value aw (moisture percentage % RH) is obtained from the moisture-in-oil meter measurement value detected by the moisture sensor 23. Possible causes of moisture abnormalities include excessive moisture contamination. A water activity value aw of 1 or a moisture percentage of 100% RH indicates that water has separated from the oil. Water that does not dissolve in the oil and separates can cause problems such as corrosion. The moisture evaluation standard (the fourth threshold) can be set to a range, for example, a water activity value aw of 0.9 or less (moisture percentage of 90% RH or less). If the moisture content is abnormal (step S14: No), the device prompts the user to perform moisture removal operations (step S15). In some cases, operation is stopped and moisture removal operations are performed. Examples of moisture removal operations include passing the oil through a moisture removal device such as an oil washer 112 or raising the oil temperature in the tank 108 to evaporate the moisture. In addition to the moisture content, abnormal moisture content can also be determined from a sudden drop in RGB or ΔE, or a sudden rise in dielectric constant.

[0040] In steps S16 to S21, the evaluation device 1 estimates and checks for abnormalities in the RPVOT residual rate / acid number ( FIG. 20 ) as follows (steps S16 to S20 will be described in detail later). That is, in steps S16 to S21, the evaluation device 1 estimates the RPVOT residual rate or acid number from the color, dielectric constant value, and trend. If the color and dielectric constant values ​​are within specified levels, the RPVOT residual rate or acid number is estimated and displayed. Which value, color or dielectric constant, is prioritized, and whether to take the average value, depends on the oil. Because oil properties (e.g., how the color changes, the amount of additives, etc.) vary depending on the type and brand of oil, the appropriate one is selected in advance. If only the dielectric constant is outside the specified level, the RPVOT residual rate or acid number is estimated and displayed based on the color. The evaluation device 1 visually checks and trends to see if there are any abnormalities in the dielectric constant sensor detection unit, such as a drop in the oil level or bubbles.

[0041] If only the color is outside the specified level, the RPVOT residual rate or acid value based on the dielectric constant is estimated and displayed. Check visually and from the trend whether there are any abnormalities in the color sensor detection section, such as a drop in oil level or air bubbles. If the color and dielectric constant values ​​are outside the specified level, check whether the moisture sensor value and contamination sensor value are within the specified range. If the moisture and contamination are within the specified range, the oil has deteriorated and an oil change is recommended. If the moisture is outside the specified range, perform moisture removal operations, and if the contamination is outside the specified range, check the filter differential pressure.

[0042] Next, the evaluation device 1 checks for abnormalities in the amount and substance of contamination (steps S22 to S25). Contamination amount information (ISO grade, NAS grade, SAE grade) is obtained from the particle meter or contamination sensor 25. If the amount of contamination is abnormal even when the oil temperature is high (during operation) (step S22: No), the difference in particle amount caused by temperature changes during operation (e.g., 60°C) and idle operation (e.g., 30°C) is confirmed (step S23). If the increased particle amount is due to hard foreign matter (such as wear debris) or clumps of oil sludge, the amount of contamination is not affected by temperature changes. In this case, the filter differential pressure check and preparation for filter replacement are recommended (steps S25 to S27). If the amount of contamination is affected by temperature changes, it is determined that the increased amount of contamination is due to an increase in oil sludge (step S26). However, if the temperature change is affected but is outside the specified level, a large amount of oil sludge has been generated, so an oil change and filter change are recommended (step S27).

[0043] In step S20, since the degree of oil degradation (RPVOT residual rate, acid value) has been observed by checking the color sensor and dielectric constant sensor in the previous steps (steps S16 to S19), if there is no abnormality in the degree of oil degradation, a normal judgment and the oil property results are displayed. Note that the order of the processes shown in Figure 3 may be reversed, or simultaneous observation may be performed. Next, steps S16 to S20 will be described in detail.

[0044] (RPVOT Residual Rate Evaluation Using Color Sensor (Step S16)) FIG. 4 is a diagram illustrating an example of the relationship between color (e.g., G (green component)) and RPVOT residual rate according to an embodiment of the present disclosure. FIG. 5 is a flowchart illustrating an example of a flow for evaluating RPVOT residual rate using a color sensor according to an embodiment of the present disclosure. Note that in the following flows, the same thresholds are assigned the same numbers (first threshold, second threshold, third threshold, ...). For example, the second threshold in FIG. 5 and the second threshold in FIG. 8 are the same value. Also, FIG. 4 and FIGS. 6, 7, 9, 11, 12, 13, 14, and 16, which will be described later, show examples of test results using a certain turbine oil. The measured values ​​and characteristics shown in these figures may differ depending on the type and brand of oil. However, the basic configuration and operation of this embodiment are not limited to turbine oil, and can also be applied to other lubricating oils, such as hydraulic oil, gear oil, and engine oil.

[0045] The relationship (correlation) between the color (e.g., G) shown in Figure 4 and the RPVOT residual rate can be obtained in advance by, for example, performing an RPVOT (Rotary Pressure Vessel Oxidation Stability Test) while acquiring color information using a color sensor similar to the color sensor 21 installed in a plant. The relationship (correlation) between the color (e.g., G) and the RPVOT residual rate is stored in advance in the correlation information storage unit 14. The correlation can be stored in the correlation information storage unit 14, for example, as information showing an equation representing a regression line or as information showing the regression line in a table. The color items used to estimate the RPVOT residual rate are usually G, B, or ΔE, and vary depending on the oil type. For example, a PC with manufacturer-specified software downloaded can be connected and measurement data can be output. Alternatively, analog signals and CAN signals from the sensor can be input to a PC and a logger and processed to obtain measurement data. The signal from the sensor depends on the communication method used. Color is not easily affected by temperature, and a correlation between color and the RPVOT residual rate was found (Figure 4). 4 shows the regression line RL, with the horizontal axis representing the RPVOT residual rate and the vertical axis representing the RGB G value. If the control value for the RPVOT residual rate (the value that must be controlled so as not to fall below this value) is set to 25%, a threshold value (referred to as the first threshold value) for the G value is set from the intersection point CP of the regression line RL and the control value. A value that is less deteriorated than the control value and is close to the control value is shown as the second threshold value.

[0046] Even if water is mixed into the oil, if it dissolves in the oil and is transparent (water activity value aw is 0.9 or less), the color is not affected by the water. However, if a large amount of water is mixed into the oil and it becomes cloudy, all RGB values ​​decrease, making it difficult to estimate the RPVOT residual rate using the color sensor, but it is possible to detect abnormalities due to water mixing. If a large amount of foreign matter is mixed into the oil, it becomes difficult to estimate the RPVOT residual rate using the color sensor 21, but if the amount is small (less than approximately 10 ppm), the impact is small. This 10 ppm is higher than the control standard value for turbine oil.

[0047] In the flow of RPVOT remaining rate evaluation using the color sensor 21 ( FIG. 5 ), the evaluation device 1 first acquires the outputs of various sensors (step S101). Next, the evaluation device 1 determines whether the color sensor information (in this case, the G value) is greater than the first threshold value ( FIG. 4 ) (step S102). Note that the color sensor information is not limited to the G value, but may also be the B value, color difference ΔE, or other information. The color sensor 21 sets the value of new oil as (R, G, B) = (255, 255, 255), and as the oil deteriorates and becomes discolored, the value decreases from 255. If the color (G or B or ΔE) is within a specified level, the RPVOT remaining rate is estimated based on the specified level and past data trends (step S103). If the value is close to the management reference value (step S104: Yes), a message is displayed indicating that the time for an oil change is approaching, prompting the user to purchase new oil (step S105).

[0048] If the color (G or B or ΔE) is below the specified level (Step S102: No), the RPVOT residual rate may be below the standard. The evaluation device 1 checks whether the color (R) value is below the specified level (defined as the third threshold) (Step S106). If the deterioration of the lubricating oil 109 progresses, the color (G), color (B), or color difference ΔE will decrease. In contrast, the color (R) rarely decreases due to the progression of oil deterioration. However, if air bubbles, dirt, etc. adhere to the detection section of the color sensor 21, all values ​​(R, G, B) will decrease. The third threshold can be a value indicating that the color (R) has decreased.

[0049] If the color (R) value is equal to or lower than the specified level (third threshold) (step S106: No), the evaluation device 1 determines whether the water activity value is lower than a fourth threshold (step S108) to check whether bubbles or stains have occurred. The fourth threshold is a predetermined value lower than "1" and may be, for example, 0.9. If the water activity value is equal to or higher than the fourth threshold (step S108: No), the evaluation device 1 increases the temperature of the tank 108 (step S109) and executes the process of step S101 again.

[0050] If the water activity value is less than the fourth threshold (step S108: Yes), the evaluation device 1 waits until a predetermined time has elapsed (step S110: No is repeated). If the predetermined time has elapsed (step S110: Yes), the evaluation device 1 issues a sensor inspection alarm (step S111). For example, the operator who received the sensor inspection alarm performs a sensor inspection until the abnormality is resolved (step S112 → step S113: No). If the abnormality is resolved (step S113: Yes), the evaluation device 1 executes the process of step S101 again.

[0051] The oil may return to normal as air bubbles, dirt, etc. are removed by the oil flow. If the measurement value remains unchanged after leaving it for a while (for example, several hours to several days), it is possible that the air bubbles or dirt have not been removed, or that the sensor has malfunctioned or the oil level has dropped, so the evaluation device 1 issues a sensor inspection alarm (step S111). Since there is also the possibility of moisture being involved, the moisture sensor measurement value is checked (step S108). If there is a moisture abnormality, measures such as raising the oil temperature in the tank are taken to evaporate the moisture. The moisture sensor value is checked again to see if the moisture in the oil has decreased (step S112).

[0052] Furthermore, if the color (R) value is within the specified level (greater than the third threshold value) (step S106: Yes), the evaluation device 1 issues an oil change alarm and prompts the user to perform an oil analysis or oil change to determine the cause (step S107).

[0053] (RPVOT residual rate evaluation using a dielectric constant sensor (step S17)) Next, the processing of step S17 in FIG. 3 will be described with reference to FIGS. 6 to 8. FIG. 6 is a diagram showing an example of the relationship between the relative dielectric constant and the RPVOT residual rate (constant oil temperature) according to an embodiment of the present disclosure. FIG. 7 is a diagram showing an example of the relationship between the temperature-corrected and moisture-corrected relative dielectric constant and the RPVOT residual rate according to an embodiment of the present disclosure. FIG. 8 is a flowchart showing an example of the flow of RPVOT residual rate evaluation using a dielectric constant sensor according to an embodiment of the present disclosure.

[0054] The relationship (correlation) between the dielectric constant and the RPVOT residual rate shown in FIG. 6 can be obtained in advance by, for example, performing a rotary pressure vessel oxidation stability test (RPVOT) while measuring the dielectric constant using the same sensor as the dielectric constant sensor 22 installed in a plant. The relationship (correlation) between the dielectric constant and the RPVOT residual rate is stored in advance in the correlation information storage unit 14. The correlation can be stored in the correlation information storage unit 14, for example, as information showing an equation representing a regression line or as information showing the regression line in a table. For example, a PC with manufacturer-specified software downloaded can be connected and measurement data can be output. Alternatively, analog signals and CAN signals from the sensor can be input to a PC and a logger and processed to obtain measurement data. The signal from the sensor depends on the communication method used. When the oil temperature is constant, a correlation between the dielectric constant (or permittivity) and the RPVOT residual rate was found ( FIG. 6 ). 6 shows a regression line RL with the horizontal axis representing the RPVOT residual rate and the vertical axis representing the dielectric constant. When the control value for the RPVOT residual rate is set to 25%, a threshold value for the dielectric constant (referred to as the sixth threshold value) is set from the intersection point CP of the regression line RL and the control value. A value that is less deteriorated than the control value and is close to the control value is shown as the second threshold value. A fifth threshold value is set as a threshold value for determining values ​​that are not normally measured as the dielectric constant of the lubricant 109.

[0055] In this embodiment, it has been confirmed that the dielectric constant is little affected by foreign matter contamination and is not affected by silica, silt, or iron powder. Furthermore, although the dielectric constant is easily affected by temperature and moisture, the RPVOT residual rate can be estimated by correcting for the temperature and moisture based on the measured temperature and water activity ( FIG. 7 ). In this embodiment, multiple regression analysis can be used as a correction method, for example. In this case, the regression equation can be expressed as follows:

[0056] ε' = ε・X

[0057] ε' = corrected relative permittivity, ε = relative permittivity measured by the sensor.

[0058] X=a+b・t+c・w

[0059] X: correction coefficient, a, b, c: constants, t: temperature, w: water activity value.

[0060] Next, referring to FIG. 8, the flow of RPVOT residual rate evaluation using the dielectric constant sensor 22 will be described. In the process shown in FIG. 8, the evaluation device 1 first acquires the outputs of various sensors (step S201). Next, the evaluation device 1 performs temperature and moisture correction of the relative dielectric constant (step S202). If the corrected dielectric constant is below a specified level (fifth threshold) (step S203: No), air bubbles or dirt may be adhering to the detection section of the dielectric constant sensor 22. The original state may return to normal if the air bubbles or dirt are removed by the flow of oil. If the measurement value remains unchanged after leaving it for a while (step S208: Yes after repeated No), a sensor failure, a low oil level, or other possible reasons may be considered in addition to the inability to remove air bubbles or dirt. Therefore, a sensor inspection alarm is issued (step S209). Note that steps S208 to S211 correspond to steps S110 to S113 in FIG. 5.

[0061] If the corrected relative permittivity is equal to or greater than the specified level (sixth threshold) (step S204: No), moisture may be affecting the system, so the moisture sensor measurement value is checked (step S212). If the moisture is abnormal (step S212: No), measures such as raising the oil temperature in the oil tank are taken (step S214) to remove the moisture. The moisture sensor value is checked again to see if the moisture in the oil has decreased. If the corrected relative permittivity is equal to or greater than the specified level and the water activity value is less than the fourth threshold (e.g., 0.9) (step S212: Yes), the degree of oil deterioration may be out of standard. The RPVOT remaining rate is estimated and an oil change alarm is issued, prompting the user to perform an oil analysis to identify the cause and an oil change (step S213).

[0062] If the corrected relative permittivity is within the specified level (step S204: Yes), the RPVOT remaining rate is estimated from the specified level and the data trend up to now (step S205).If the control standard value is close (step S206: No), a message is displayed indicating that the time for oil change is approaching, and the user is prompted to purchase oil, etc. (step S207).

[0063] (Acid value evaluation using a color sensor (step S18)) Next, the processing of step S18 in FIG. 3 will be described with reference to FIGS. 9 and 10. FIG. 9 is a diagram showing an example of the relationship between color (G) and acid value according to an embodiment of the present disclosure. FIG. 10 is a flowchart showing an example of the flow of acid value evaluation using a color sensor according to an embodiment of the present disclosure.

[0064] The relationship (correlation) between color (G) and acid value shown in FIG. 9 can be obtained in advance, for example, by using the same sensor as the color sensor 21 installed in a plant or the like to measure the color of the lubricating oil 109 multiple times while varying the acid value. The relationship (correlation) between color and acid value is pre-stored in the correlation information storage unit 14. The correlation can be stored in the correlation information storage unit 14, for example, as information showing an equation representing a regression line or as information showing the regression line in a table. For example, a PC with manufacturer-specified software downloaded can be connected and measurement data can be output. Alternatively, analog signals and CAN signals from the sensor can be input to a PC and a logger and processed to obtain measurement data. The signal from the sensor depends on the communication method of the sensor used. A correlation between color (G) and acid value, shown by the solid line, was found for acid values ​​within the control standard ( FIG. 9 ). The "control standard" here refers to the acid value when the control value is set to an RPVOT residual rate of 25% or more in the relationship between RPVOT residual rate and acid value, as shown in FIG. 11 (described below). 9 shows the regression line RL, with the acid number on the horizontal axis and color (G) on the vertical axis. The control value for the acid number is set to the new oil value + α (any real number), and a threshold value (referred to as the seventh threshold value) for color (G) is set from the intersection CP of the regression line RL and the control value. A value that is less deteriorated than the control value and is close to the control value is defined as the increase from the new oil value (the eighth threshold value).

[0065] Next, the flow of acid value evaluation using the color sensor 21 will be described with reference to FIG. 10. In the process shown in FIG. 10, the evaluation device 1 inputs the acid value of a new oil (step S301). Next, the evaluation device 1 acquires the outputs of various sensors (step S302). Next, the evaluation device 1 determines whether the color sensor information (in this case, color (G)) is greater than a seventh threshold (step S303).

[0066] If the color (G or B or ΔE) is within the specified level (Step S303: Yes), the evaluation device 1 estimates the acid number from the specified level and the data trend up to now (Step S304). If the increase from the new oil price is close to the control reference value (Step S305: Yes), a message is displayed indicating that the time for an oil change is approaching, and a prompt to purchase oil is made (Step S306).

[0067] If the color (G or B or ΔE) is equal to or less than a specified level (for example, a seventh threshold) (step S303: No), the acid value may be out of standard (above the control value). The evaluation device 1 checks whether the color (R) value is equal to or less than a specified level (a third threshold) (step S307).

[0068] If the color (R) value is equal to or lower than the specified level (third threshold) (step S307: No), the evaluation device 1 determines whether the water activity value is lower than the fourth threshold (step S309) to check whether bubbles or stains are present. If the water activity value is equal to or higher than the fourth threshold (step S309: No), the evaluation device 1 increases the temperature of the tank 108 (step S310) and executes the process of step S302 again.

[0069] If the water activity value is less than the fourth threshold (step S309: Yes), the evaluation device 1 waits until a predetermined time has elapsed (step S311: No is repeated). If the predetermined time has elapsed (step S311: Yes), the evaluation device 1 issues a sensor inspection alarm (step S312). For example, the operator who received the sensor inspection alarm performs a sensor inspection until the abnormality is resolved (step S313 → step S314: No). If the abnormality is resolved (step S314: Yes), the evaluation device 1 executes the process of step S302 again.

[0070] The oil may return to normal as air bubbles, dirt, etc. are removed by the oil flow. If the measurement value remains unchanged after leaving it for a while (for example, several hours to several days), the evaluation device 1 issues a sensor inspection alarm (step S312), as this may be due to sensor failure, a drop in the oil level, or other reasons, in addition to the air bubbles or dirt not being removed. The moisture sensor measurement value is checked (step S309), as this may also be due to moisture. If there is a moisture abnormality, measures such as raising the oil temperature in the tank are taken to evaporate the moisture. The moisture sensor value is checked again, and it is observed whether the moisture in the oil has decreased (step S313).

[0071] Furthermore, if the color (R) value is within the specified level (greater than the third threshold value) (step S307: Yes), the evaluation device 1 issues an oil change alarm and prompts the user to perform an oil analysis or oil change to determine the cause (step S308).

[0072] (Comparison of RPVOT Residual Value and Acid Value) In this embodiment, as described below, the acid value, which is an indicator of oxidative degradation of oil that cannot be measured directly by a sensor, is estimated from the dielectric constant, which is sensor information. By continuously estimating the acid value through sensor measurement and accumulating sensor information to obtain a trend, or by using sensor information near the control reference value as a basis, it is possible not only to detect oil degradation but also to predict before it falls outside the control reference value. Furthermore, when the acid value increases suddenly, such as at the end of oil degradation, it is possible to determine whether the acid value has exceeded the control reference value, leading to abnormality detection. The timing of oil change is determined using the RPVOT residual rate or acid value as an indicator, and depending on the type of oil, management and judgment may be based on the acid value rather than the RPVOT residual rate (e.g., gear oil).

[0073] The acid value indicates the amount of acidic components, such as additives and base oil-derived degradation products. In contrast, the RPVOT residual rate (RPVOT) captures the additive consumption rate, while the acid value captures oxidation products. Therefore, additive consumption leads to a loss of oxidation inhibitory power, resulting in a rapid change. An excessive increase in acid value can lead to sludge formation and corrosion of metal surfaces, potentially causing mechanical equipment problems. Figure 11 shows the relationship between acid value and RPVOT residual rate for a certain turbine oil. As shown in Figure 11, the acid value increases gradually from the early to mid-stages of oil degradation (e.g., RPVOT residual rate of 100-50%). The acid value rarely exceeds the control standard (e.g., acid value of new oil + 0.4 mg KOH / g) before the RPVOT residual rate falls outside the control standard (e.g., RPVOT residual rate of 25% or less). However, the acid value increases rapidly toward the end of oil degradation, so caution is required when using oil close to the control standard to its limits. In this embodiment, the acid value can be estimated and changes in deterioration can be observed, making it possible to perform CBM (condition-based maintenance) management and expected to reduce oil purchasing and management costs.

[0074] (Acid number evaluation using a dielectric sensor (step S19)) Next, the processing of step S19 in FIG. 3 will be described with reference to FIGS. 12 to 15. FIG. 12 is a diagram showing an example of the relationship between the relative dielectric constant (at constant or corrected oil temperature) and the acid number according to an embodiment of the present disclosure. FIG. 13 is a diagram showing an example of the relationship between the relative dielectric constant (at constant or corrected oil temperature) and the acid number within the control standard according to an embodiment of the present disclosure. FIG. 14 is a diagram showing an example of the relationship between the rate of change in the relative dielectric constant and the acid number according to an embodiment of the present disclosure. FIG. 15 is a flowchart showing an example of the flow of acid number evaluation using a dielectric sensor according to an embodiment of the present disclosure.

[0075] The relationship (correlation) between the dielectric constant and the acid number shown in FIG. 12 can be obtained in advance, for example, by varying the acid number of the lubricating oil 109 using the same dielectric constant sensor 22 installed in a plant or the like and measuring the dielectric constant multiple times with the dielectric constant sensor 22. The relationship (correlation) between the dielectric constant and the acid number is stored in advance in the correlation information storage unit 14. The correlation can be stored in the correlation information storage unit 14, for example, as information showing an equation representing a regression line or as information showing the regression line in a table. For example, a PC with manufacturer-specified software downloaded can be connected and measurement data can be output. Alternatively, analog signals and CAN signals from the sensor can be input to a PC and a logger and processed to obtain measurement data. The signal from the sensor depends on the communication method of the sensor used. When the oil temperature is constant, a correlation between the dielectric constant (or dielectric constant) and the acid number was found ( FIG. 12 ). FIG. 12 shows the regression line RL, with the acid number on the horizontal axis and the dielectric constant on the vertical axis. The control value of the acid number is set to the new oil value + α (any real number), and a threshold value (referred to as the ninth threshold value) for the dielectric constant is set from the intersection CP of the regression line RL and the control value. A value that is less deteriorated than the control value and is close to the control value is defined as the increase from the new oil value (the eighth threshold value). Figure 13 shows the correlation between the acid number and the dielectric constant in the low acid number range.

[0076] Furthermore, as shown in Figure 14, there was a linear correlation between the rate of change in dielectric constant and the acid number when compared to new oil. For this reason, the flow shown in Figure 15 also includes an evaluation using the correlation shown in Figure 14. The rate of change in dielectric constant compared to the new oil value is expressed by the following formula.

[0077] Percentage change in dielectric constant compared to new oil value (%) = (measured value - new oil value) / new oil value x 100

[0078] In the above equation, "measured value" refers to the measured value (also referred to as the observed value) of the dielectric constant or relative permittivity, and "new oil value" refers to the measured value (also referred to as the observed value) of the dielectric constant or relative permittivity of new oil. Figure 14 shows the acid number on the horizontal axis and the "percentage change in dielectric constant compared to the new oil value" on the vertical axis, along with the measured values ​​(black circles) and the regression line RL. The control value for the acid number is set to new oil value + α (any real number), and a threshold value (referred to as the 10th threshold value) for the "percentage change in dielectric constant compared to the new oil value" is set from the intersection CP of the regression line RL and the control value. A value that is less deteriorated than the control value and is close to the control value is defined as the increase from the new oil value (the 8th threshold value).

[0079] Next, referring to FIG. 15, the flow of acid number evaluation using the dielectric constant sensor 22 will be described. In the process shown in FIG. 15, the evaluation device 1 first inputs the acid number of the new oil (step S401). Next, the evaluation device 1 acquires the outputs of various sensors (step S402). Next, the evaluation device 1 performs temperature and moisture correction of the relative dielectric constant (step S403). If the corrected dielectric constant is below the specified level (fifth threshold) (step S404: No), air bubbles or dirt may have adhered to the detection section of the dielectric constant sensor 22. The original state may return to normal if the air bubbles or dirt are removed by the oil flow. If the measurement value remains unchanged after leaving it for a while (step S409: No repeatedly), a sensor inspection alarm is issued (step S410), indicating that the air bubbles or dirt have not been removed, or that the sensor may have malfunctioned or the oil level may have dropped. Note that steps S409 to S412 correspond to steps S110 to S113 in FIG. 5.

[0080] If the corrected relative permittivity is equal to or greater than the specified level (ninth threshold) or the rate of change in the permittivity compared to the corrected new oil value is equal to or greater than the specified level (tenth threshold) (step S405: No), moisture may be affecting the oil, so the moisture sensor measurement value is checked (step S413). If the moisture is abnormal (step S413: No), measures such as raising the oil temperature in the oil tank are taken (step S415) to remove the moisture. The moisture sensor value is checked again to see if the moisture in the oil has decreased. If the corrected relative permittivity is equal to or greater than the specified level (ninth threshold) or the rate of change in the permittivity compared to the corrected new oil value is equal to or greater than the specified level (tenth threshold), and the water activity value is less than the fourth threshold (e.g., 0.9) (step S413: Yes), the degree of oil deterioration may be out of standard. An acid value is estimated and an oil change alarm is issued, prompting the user to perform an oil analysis to identify the cause and an oil change (step S414).

[0081] If the corrected relative permittivity is within a specified level (less than the ninth threshold) or the rate of change in permittivity compared to the corrected new oil value is within a specified level (less than the tenth threshold) (step S405: Yes), the acid number is estimated from the specified level and the data trend up to now (step S406).If the control standard value is close (step S407: No), a message is displayed indicating that the time for an oil change is approaching, and a user is prompted to purchase oil, etc. (step S408).

[0082] Next, another example of the process of step S19 in Fig. 3 will be described with reference to Fig. 16 and Fig. 17. Fig. 16 is a diagram showing an example of the relationship between the amount of change in relative dielectric constant per unit time and the acid value according to an embodiment of the present disclosure. Fig. 17 is a flowchart showing another example of the flow of acid value evaluation using a dielectric constant sensor according to an embodiment of the present disclosure.

[0083] As shown in Figure 16, the relationship (correlation) between the change in dielectric constant per unit time and the acid number indicates that as the change in dielectric constant per unit time decreases, the acid number approaches a point (control value, service limit value) where a rapid increase in the acid number occurs. Figure 16 shows the acid number on the horizontal axis and the change in dielectric constant per unit time on the vertical axis, along with a regression line RL. The control value for the acid number is set to new oil value + α (any real number), and a threshold value (referred to as the 11th threshold value) for the change in dielectric constant per unit time is set from the intersection CP of the regression line RL and the control value. A value that is less deteriorated than the control value and is close to the control value is defined as the increase from the new oil value (the 8th threshold value).

[0084] Fig. 17 shows an example of processing when the amount of change in permittivity per unit time is used as an evaluation parameter. In the processing (shown as step S405a) shown in Fig. 17, the determination content of step S405 shown in Fig. 15 is changed to the corrected permittivity (relative permittivity) < the ninth threshold, or the amount of change in the corrected permittivity (relative permittivity) per unit time > the eleventh threshold.

[0085] (Effects) In the evaluation device and evaluation method configured as described above, the degree of deterioration of a lubricant is evaluated based on the results of comparing the observed values ​​of observable parameters (color, color difference, dielectric constant, relative permittivity) that are correlated with the RPVOT residual rate and represent the properties of the lubricant with the values ​​of the parameters (first threshold, sixth threshold) that correspond to a predetermined value (e.g., a control value) of the RPVOT residual rate based on a previously acquired correlation. According to this aspect, the degree of deterioration of a lubricant can be appropriately evaluated.

[0086] The parameters are values ​​related to the color or color difference, or the dielectric constant or relative dielectric constant of the lubricating oil.

[0087] Furthermore, only when the water activity value of the lubricant is within a predetermined range (step S106: Yes, step S212: Yes), the degree of deterioration of the lubricant is evaluated.

[0088] Also, if the color of the lubricant is expressed by multiple color components, one color component is used as a parameter, and when the other color components are within a predetermined range (step S106: Yes), the degree of deterioration of the lubricant is evaluated (step S102).

[0089] In addition, if the parameter is a value related to the dielectric constant or relative permittivity of the lubricant, the degree of deterioration of the lubricant is evaluated based on a value obtained by correcting the dielectric constant or relative permittivity of the lubricant based on the water activity value and temperature of the lubricant (step S202).

[0090] Furthermore, in the evaluation device and evaluation method configured as described above, the degree of deterioration of the lubricant is evaluated based on the results of a comparison between an observed value of an observable parameter (the rate of change in dielectric constant compared to the new oil value) that is correlated with the acid number and represents the properties of the lubricant, and a value (tenth threshold) of the parameter that corresponds to a predetermined value of the acid number (e.g., a control value) based on a previously acquired correlation. Here, the parameter is the difference between the measured value of the dielectric constant or relative permittivity of the lubricant and the new oil value of the dielectric constant or relative permittivity of the lubricant, divided by the new oil value.

[0091] In addition, the evaluation device and evaluation method configured as described above evaluate the degree of deterioration of a lubricant based on a comparison result between an observable parameter (amount of change in dielectric constant per unit time) that is correlated with the acid number and represents the properties of the lubricant, and the observed value of the parameter and the value of the parameter (eleventh threshold value) that corresponds to a predetermined value of the acid number (e.g., a control value) based on a previously acquired correlation. Here, the parameter is the amount of change in the dielectric constant or relative permittivity of the lubricant per unit time.

[0092] Furthermore, with the evaluation device 1 and evaluation system 100 of this embodiment, the RPVOT residual rate can be estimated from the correlation between color, dielectric constant, and RPVOT residual rate, allowing the progression of oil degradation to be observed. Furthermore, the acid value can be estimated from the correlation between dielectric constant and acid value, allowing the progression of oil degradation to be observed. When the color becomes cloudy due to moisture contamination, the measured value drops, making it difficult to distinguish from oil degradation. However, by checking the moisture sensor and eliminating any abnormalities due to moisture contamination in advance, the RPVOT residual rate can be easily estimated. The dielectric constant is easily affected by temperature and moisture, but by checking the moisture sensor and eliminating any abnormalities due to moisture in advance, and applying a temperature / moisture correction formula, the RPVOT residual rate and acid value can be easily estimated. Being able to estimate oil degradation is expected to help predict and reduce problems in machinery and equipment. It is possible to predict when the control value will be reached (for example, in the case of turbine oil management, when the RPVOT residual rate is 25% or the acid value is 0.4 mgKOH / g above the new oil value), allowing the oil to be used to its limit and determining the timing for purchasing new oil. In other words, it is useful for CBM management (condition-based maintenance). In addition, changes in the contamination sensor's measurement value due to temperature changes make it possible to distinguish whether the mixed particles are oil sludge or hard foreign matter, making it easier to determine the next action to take, such as whether to prepare filters or oil.

[0093] (Other Embodiments) Although the embodiments of the present disclosure have been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design modifications and the like are also included within the scope of the present disclosure. For example, the above-described change per unit time may be evaluated in place of or in addition to the time change of the change per unit time. Furthermore, application fields of the present disclosure include, but are not limited to, GTCC plants (gas turbine combined cycle power plants), GT plants (gas turbine power plants), ST plants (steam turbine power plants), data centers, hydraulic drive systems, and the like.

[0094] <Computer Configuration> Fig. 21 is a schematic block diagram showing the configuration of a computer according to an embodiment of the present disclosure. The computer 90 includes a processor 91, a main memory 92, a storage 93, and an interface 94. The evaluation device 1 described above is implemented in the computer 90. The operations of each of the processing units described above are stored in the storage 93 in the form of a program. The processor 91 reads the program from the storage 93, loads it into the main memory 92, and executes the above-described processing in accordance with the program. The processor 91 also allocates storage areas in the main memory 92 corresponding to each of the storage units described above in accordance with the program.

[0095] The program may be for realizing some of the functions to be performed by the computer 90. For example, the program may be combined with other programs already stored in storage or implemented in other devices to perform the functions. In other embodiments, the computer may include a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to or instead of the above configuration. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, some or all of the functions realized by the processor may be realized by the integrated circuit.

[0096] Examples of storage 93 include a hard disk drive (HDD), a solid state drive (SSD), a magnetic disk, a magneto-optical disk, a compact disc read-only memory (CD-ROM), a digital versatile disc read-only memory (DVD-ROM), and a semiconductor memory. Storage 93 may be an internal medium directly connected to the bus of computer 90, or an external medium connected to computer 90 via interface 94 or a communication line. Furthermore, if this program is distributed to computer 90 via a communication line, computer 90 that receives the program may load the program into main memory 92 and execute the above-described processing. In at least one embodiment, storage 93 is a non-transitory tangible storage medium.

[0097] <Additional Notes> The evaluation device and evaluation method described in the embodiments of the present disclosure can be understood, for example, as follows.

[0098] (1) The evaluation device 1 according to a first aspect includes an acquisition unit 11 that acquires observed values ​​of observable parameters that are correlated with the RPVOT residual rate and represent the properties of the lubricant, a calculation unit 12 that calculates an estimated value of the RPVOT residual rate corresponding to the observed value based on the correlation, and an output unit 16 that outputs an evaluation result regarding the degree of deterioration of the lubricant based on the estimated value. According to this aspect and each of the following aspects, the degree of deterioration of the lubricant can be appropriately evaluated.

[0099] (2) The evaluation device 1 according to a second aspect is the evaluation device 1 of (1), in which the parameter is the color or color difference, or the dielectric constant or relative dielectric constant of the lubricating oil.

[0100] (3) The evaluation device 1 according to a third aspect is the evaluation device 1 according to (1) or (2), wherein the output unit outputs the evaluation result when the water activity value of the lubricating oil is within a predetermined range. According to this aspect, it is possible to prevent an erroneous evaluation result from being output.

[0101] (4) The evaluation device 1 according to a fourth aspect is the evaluation device 1 according to any one of (1) to (3), wherein the parameter is the green component, the blue component, or the color difference when the color of the lubricant is expressed using three color components, i.e., a red component, a green component, and a blue component, and the output unit outputs the evaluation result when the red component is within a predetermined range. This aspect makes it possible to prevent an erroneous evaluation result from being output.

[0102] (5) The evaluation device 1 according to a fifth aspect is the evaluation device 1 of any one of (1) to (4), wherein the parameter is the dielectric constant or relative dielectric constant of the lubricant, and the calculation unit calculates, based on the correlation, an estimated value of the RPVOT residual ratio corresponding to a value obtained by correcting the observed value based on the water activity value and temperature of the lubricant. According to this aspect, the RPVOT residual ratio can be estimated with high accuracy.

[0103] (6) The evaluation device 1 according to the sixth aspect is the evaluation device 1 of any one of (1) to (5), and is provided with an acquisition unit that acquires an observed value of the parameter, which is an observable parameter that is correlated with the acid number and represents the properties of the lubricant, a calculation unit that calculates an estimated value of the acid number corresponding to the observed value based on the correlation, and an output unit that outputs an evaluation result regarding the degree of deterioration of the lubricant based on the estimated value, and the parameter is the difference between the measured value of the dielectric constant or relative dielectric constant of the lubricant and the new oil value of the dielectric constant or relative dielectric constant of the lubricant, divided by the new oil value.

[0104] (7) The evaluation device 1 according to the seventh aspect is the evaluation device 1 of (1) to (5), and is provided with an acquisition unit that acquires an observed value of an observable parameter that is correlated with the acid number and represents the properties of the lubricating oil, a calculation unit that calculates an estimated value of the acid number corresponding to the observed value based on the correlation, and an output unit that outputs an evaluation result regarding the degree of deterioration of the lubricating oil based on the estimated value, wherein the parameter is the amount of change per unit time in the dielectric constant or relative dielectric constant of the lubricating oil.

[0105] (8) The evaluation method according to the eighth aspect includes the steps of: acquiring an observed value of an observable parameter that is correlated with the RPVOT residual rate and that represents the properties of the lubricant; calculating an estimated value of the RPVOT residual rate that corresponds to the observed value based on the correlation; and outputting an evaluation result regarding the degree of deterioration of the lubricant based on the estimated value.

[0106] (9) The evaluation method according to the ninth aspect includes the steps of: acquiring an observed value of an observable parameter that is correlated with the acid number and represents the properties of the lubricant; calculating an estimated value of the acid number corresponding to the observed value based on the correlation; and outputting an evaluation result regarding the degree of deterioration of the lubricant based on the estimated value, wherein the parameter is a value obtained by dividing the difference between the measured value of the dielectric constant or relative permittivity of the lubricant and the new oil value of the dielectric constant or relative permittivity of the lubricant by the new oil value.

[0107] (10) An evaluation method according to a tenth aspect includes the steps of: acquiring an observed value of an observable parameter that is correlated with acid number and represents the properties of the lubricating oil; calculating an estimated value of the acid number corresponding to the observed value based on the correlation; and outputting an evaluation result regarding the degree of deterioration of the lubricating oil based on the estimated value, wherein the parameter is the amount of change per unit time in the dielectric constant or relative dielectric constant of the lubricating oil.

[0108] According to the evaluation device and evaluation method of the present disclosure, the degree of deterioration of a lubricating oil can be appropriately evaluated.

[0109] DESCRIPTION OF SYMBOLS 1...Evaluation device 11...Acquisition unit 12...Calculation unit 16...Output unit 100...Evaluation system 109...Lubricant

Claims

1. An evaluation device comprising: an acquisition unit that acquires an observed value of an observable parameter that is correlated with the RPVOT (Rotating Pressure Vessel Oxidation Test) residual rate and that represents the properties of the lubricant; a calculation unit that calculates an estimated value of the RPVOT residual rate corresponding to the observed value based on the correlation; and an output unit that outputs an evaluation result regarding the degree of deterioration of the lubricant based on the estimated value.

2. The evaluation device according to claim 1, wherein the parameter is the color or color difference, or the dielectric constant or relative dielectric constant of the lubricating oil.

3. The evaluation device according to claim 2, wherein the output unit outputs the evaluation result when the water activity value of the lubricating oil is within a predetermined range.

4. The evaluation device according to claim 3, wherein the parameter is the green component, the blue component, or the color difference when the color of the lubricant is expressed using three color components: red, green, and blue; and the output unit outputs the evaluation result when the red component is within a predetermined range.

5. The evaluation device according to claim 4, wherein the parameter is the dielectric constant or relative dielectric constant of the lubricant, and the calculation unit calculates, based on the correlation, an estimated value of the RPVOT residual rate corresponding to a value obtained by correcting the observed value based on the water activity value and temperature of the lubricant.

6. An evaluation device comprising: an acquisition unit that acquires an observed value of an observable parameter that is correlated with acid number and represents the properties of a lubricant; a calculation unit that calculates an estimated value of the acid number corresponding to the observed value based on the correlation; and an output unit that outputs an evaluation result regarding the degree of deterioration of the lubricant based on the estimated value, wherein the parameter is a value obtained by dividing the difference between the measured value of the dielectric constant or relative permittivity of the lubricant and a new oil value of the dielectric constant or relative permittivity of the lubricant by the new oil value.

7. An evaluation device comprising: an acquisition unit that acquires an observed value of an observable parameter that is correlated with acid number and represents the properties of a lubricating oil; a calculation unit that calculates an estimated value of the acid number corresponding to the observed value based on the correlation; and an output unit that outputs an evaluation result regarding the degree of deterioration of the lubricating oil based on the estimated value, wherein the parameter is the amount of change per unit time in the dielectric constant or relative dielectric constant of the lubricating oil.

8. An evaluation method comprising the steps of: acquiring an observed value of an observable parameter that is correlated with the RPVOT (Rotating Pressure Vessel Oxidation Test) residual rate and that represents the properties of the lubricant; calculating an estimated value of the RPVOT residual rate that corresponds to the observed value based on the correlation; and outputting an evaluation result regarding the degree of deterioration of the lubricant based on the estimated value.

9. An evaluation method comprising the steps of: acquiring an observed value of an observable parameter that is correlated with acid number and represents a property of a lubricant; calculating an estimated value of the acid number corresponding to the observed value based on the correlation; and outputting an evaluation result regarding the degree of deterioration of the lubricant based on the estimated value, wherein the parameter is a value obtained by dividing the difference between the measured value of the dielectric constant or relative permittivity of the lubricant and a new oil value of the dielectric constant or relative permittivity of the lubricant by the new oil value.

10. An evaluation method comprising the steps of: acquiring an observed value of an observable parameter that is correlated with acid number and represents a property of the lubricating oil; calculating an estimated value of the acid number corresponding to the observed value based on the correlation; and outputting an evaluation result regarding the degree of deterioration of the lubricating oil based on the estimated value, wherein the parameter is the amount of change per unit time in the dielectric constant or relative dielectric constant of the lubricating oil.

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