JP2022117273A - Method for diagnosis of lubricating oil, device and system - Google Patents

Abstract

To provide a highly reliable remaining life diagnostic technique for the lubricating oil of a machine such as a wind power generator or a gas turbine.SOLUTION: In a method for diagnosis of the lubricating oil containing an additive agent used in a machine, information showing a relationship between a first result and a second result is prepared on the basis of the first result which is a result from the electrochemical measurement obtained separately in advance and the second result which is a result from the optical type measurement obtained separately in advance, and a first data based on the result obtained by measuring the lubricating oil containing the additive agent used in the machine based on the information by the electrochemical measurement and a second data based on the result obtained by measuring the lubricating oil containing the additive agent used in the machine by the optical type measurement are made convertible.SELECTED DRAWING: Figure 10

Description

TECHNICAL FIELD The present invention relates to a lubricating oil, a diagnostic method and a diagnostic system for a machine that uses the lubricating oil, and more particularly to a remaining life diagnosis of the lubricating oil.

For example, the property diagnosis of lubricating oil used in rotating parts such as bearings and gears is an important technique for the maintenance of large rotating machinery. Examples of large rotating machines include gearboxes of wind power generators, air compressors, ships, and power generation turbines.

There are types of lubricating oils, such as engine oil, turbine oil, hydraulic oil, bearing oil, sliding surface oil, gear oil, compressor oil, and cutting oil, depending on the purpose of use.

FIG. 1 shows a list of additives added to various lubricating oils. As shown in the figure, various additives are blended so that various lubricating oils satisfy the required performance.

Machine condition monitoring in recent years often takes a strategy that minimizes the life cycle cost of the machine. Large machines such as power generation turbines use a large amount of lubricating oil, and lubricating oil must be replaced by stopping the machine. , oil change work cost, waste oil cost, etc. are required, so it is desirable to use the lubricating oil as long as possible.

Lubricating oil property diagnosis is roughly divided into two types: (1) oxidative deterioration of lubricating oil over time; and (2) contamination by external contaminants such as water, dust, and abrasion powder.

(1) Oxidative deterioration of lubricating oil includes deterioration due to oxidation of base oil and deterioration due to consumption of additives. Oxidative deterioration of lubricating oil causes deterioration of wear resistance, changes in viscosity and viscosity index, deterioration of rust resistance, and deterioration of corrosion resistance. As a result, wear and material fatigue of the gearbox may be accelerated.

While we want to use lubricating oil for as long as possible, it is necessary to quickly change the oil and inspect the equipment if there is abnormal deterioration or contamination. Are known. Voltammetry is a type of electrochemical analysis method in which the electric potential applied to the oil to be measured is changed and the electric current that changes in response is measured.

Lubricating oil diagnosis uses linear sweep voltammetry, which continuously changes the electrode potential and measures the current value that flows due to chemical reactions in the oil. This method is hereinafter referred to as the voltammetry method. When the lubricating oil is measured by the voltammetric method, the antioxidant contained in the lubricating oil electrochemically reacts at the appropriate potential, and current flows at that time.

Antioxidants include types such as phenol, amine, and ZDDP (zinc dialkyldithiophosphate), and each type has a different reaction potential. In addition, since the voltammetry method uses a constant amount of oil sample for each measurement, the current value when the electrochemical reaction occurs is proportional to the concentration of each antioxidant in the lubricating oil. Therefore, if the potential and current value are known, the type and concentration of the antioxidant can be known. By this method, the residual concentration of antioxidant in the lubricating oil can be determined, and the remaining life of the lubricating oil can be determined. As a diagnostic method using this technology, ASTM D6810 RULER (trademark) (Remaining Useful Life Evaluation Routine, RULER) is known.

Contamination of lubricating oil in (2) is caused by water, dust, abrasion powder generated from rotating parts, and the like. Water contamination causes deterioration of lubricating performance due to changes in lubricating oil viscosity, corrosion and rusting of metal parts, and deterioration of materials. Dust itself rarely causes a fatal failure, but it may cause an increase in metal wear debris. Wear debris is known to be a fatal cause of machine failure depending on its size.

A small amount of lubricating oil for rotating machines such as gearboxes is sampled at predetermined intervals and sent to an analysis center, etc., where viscosity, degree of contamination, total acid value, metal concentration, etc. are analyzed and properties are monitored. I have something to do. In addition, state monitoring is performed by a group of sensors installed in the wind power generator (for example, sensors for output, generator speed, amount of power generation, oil temperature, oil pressure, acceleration, etc.).

Conventionally, as a lubricating oil property diagnosis technique, for example, there is one described in Patent Document 1. Patent Literature 1 discloses that the decrease (consumption degree) of additives in lubricating oil, which is an index of deterioration of lubricating oil, can be obtained from the chromaticity measured by an optical sensor.

Japanese Patent Application Laid-Open No. 2020-12690

Lubricating oils contain various additives to maintain lubricating performance. For example, if the lubricating conditions are severe and the pressure at the contact point is high, the sliding speed is slow, or the viscosity of the oil is too low, the film of lubricating oil between the friction surfaces will become thin and the frictional resistance will decrease. It grows and wears out. This condition is called boundary lubrication, and seizing occurs in extreme cases. Additives work to reduce friction and wear in such a state of boundary lubrication. Also called a load bearing additive. There are also other additives such as antioxidants and defoamers. It is necessary for the additive to be contained in a predetermined ratio (concentration) in the lubricating oil in order to maintain the desired lubricating performance.

Lubricating oil is composed of base oil for forming an optimum lubricating film for machines and additives for improving functions such as lubricating performance, extreme pressure properties, anti-corrosion properties and anti-foaming properties. In particular, antioxidants are contained in almost all lubricating oils to prevent deterioration of lubricity due to oxidation of base oil and increased risk of rust and corrosion due to increased acidity of lubricating oil. When the concentration of the antioxidant falls below a predetermined concentration, there is a problem that the viscosity and acidity of the lubricating oil rise sharply.

Consuming load-bearing additives and antioxidants in the lubricating oil is monitored while the machine is in use, the remaining life of the lubricating oil is determined, and the lubricating oil is replaced when the condition is good. It is necessary to optimize the lubricating oil change cycle by continuing to operate the machine without performing maintenance and changing the lubricating oil early if the condition of the lubricating oil is poor.

As mentioned earlier, the remaining life of lubricants can be diagnosed by the voltammetry method. There was a method of measuring the remaining amount of

However, the development of additives has progressed, the types of antioxidants have increased, and the structure of antioxidants has become complicated. Therefore, it may be difficult to evaluate with the conventional classification such as phenol, amine, and ZDDP. . In recent years, large machines such as offshore wind power generators have been equipped with various oil sensors, acceleration sensors, etc., and are constantly monitored online. It has been recognized that the rate will increase, but the problem has been that there is no method that can be measured online using the voltammetry method.

Wind power generators are required to have high-level, stable operation and power generation, and reliability that can withstand long-term use of 20 to 25 years. Therefore, it is necessary to reduce downtime by providing a predictive diagnosis function that detects anomalies before failures or other anomalies occur. In addition, since expensive parts such as gearboxes are used, predictive diagnosis is required to prevent failures before they occur. For this reason, it is necessary to know the condition of the lubricating oil with high accuracy on site.

Lubricating oil needs to be replaced periodically because its lubricating performance deteriorates due to consumption of additives. However, since it is necessary to stop the operation in order to replace the lubricating oil, a power generation amount loss occurs. In addition, replacing the lubricating oil requires the cost of new oil, waste oil, and workers, and the high cost of replacing the lubricating oil has been a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a highly reliable remaining life diagnosis technology for lubricating oil in machines such as wind power generators and gas turbines.

A preferred aspect of the present invention is a method for diagnosing a lubricating oil containing an additive used in a machine, wherein the first result, which is the result of electrochemical measurement obtained separately in advance, and the optical Preparing information indicating the relationship between the first result and the second result based on a second result, which is the result of the formula measurement, and based on the information, including additives used in the machine It is possible to convert a first data based on an electrochemical measurement of a lubricating oil and a second data based on an optical measurement of a lubricating oil containing additives used in the machine. A method for diagnosing a lubricating oil characterized by:

Another preferred aspect of the present invention is a diagnostic device for lubricating oil containing additives used in machines, in which a first result obtained separately in advance, which is a result of electrochemical measurement, and a first result obtained separately in advance , a second result that is a result of optical measurement, and a correlation database that records information indicating the relationship between the first result and the second result based on a first data set based on the results of electrochemical measurement of a lubricating oil containing additives used in said machine, and a second set of data based on the results of an optical measurement of a lubricating oil containing additives used in said machine. , and a data converter for converting.

Another preferred aspect of the present invention is a diagnostic system for a lubricating oil containing additives used in machinery, comprising: an optical sensor for obtaining color information of the lubricating oil; a data conversion unit for deriving the amount of the additive from the color information; a correlation database referred to by the data conversion unit; The correlation database is information indicating the relationship between the first result, which is the additive quantification result obtained by electrochemical measurement in advance, and the second result, which is the color information of the lubricating oil obtained in advance by optical measurement. Lubricant diagnostic system.

According to the present invention, it is possible to provide a highly reliable remaining life diagnosis technology for lubricating oil in machines such as wind power generators and gas turbines. Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

FIG. 4 is a chart showing types of additives for various lubricants; Schematic overall configuration diagram of a wind power generator. Graph diagram showing the relationship between voltage and current obtained by the voltammetry method. FIG. 2 is a graphical representation showing the reduction of antioxidant BHT with lubricating oil use. FIG. 2 is a graphical representation showing the reduction of antioxidant DPA with lubricating oil use. FIG. 2 is a graph showing the relationship between the antioxidant BHT concentration in the lubricating oil and the color of the lubricating oil. The block diagram of the rotating machine provided with the sensor for lubricating oil of an Example. FIG. 2 is a configuration diagram of a lubricating oil flow path of a rotating machine equipped with a lubricating oil sensor according to an embodiment; Lubricating oil diagnosis flow chart. FIG. 2 is a functional block diagram showing programs and data configurations stored by a central server 240. FIG. FIG. 2 is a graph showing reduction of antioxidant BHT in lubricating oil of Examples. FIG. 2 is a graph showing reduction of antioxidant DPA in lubricating oil of the Examples. FIG. 2 is a graph showing the relationship between the antioxidant BHT concentration in the lubricating oil and the color of the lubricating oil in Examples. FIG. 2 is a graph showing the relationship between the antioxidant DPA concentration in the lubricating oil and the color of the lubricating oil in Examples. Graph diagram showing the remaining life diagnosis of the embodiment. Graph diagram showing the remaining life diagnosis of the embodiment.

For example, equipment such as wind power generators must continue to operate stably at a high level over a long period of time, so it is necessary to monitor the properties of lubricating oil over a long period of time. In facilities that have been monitoring the properties of lubricating oil using the conventional voltammetry method, the voltammetry method must continue to be used to ensure the continuity of time-series measurement data. For this reason, even if it is possible to remotely monitor the properties of lubricating oil using the optical sensor described in Patent Document 1, for example, it has been impossible to switch the measuring method.

In a typical embodiment described in the Examples, the results of the voltammetry method, which were previously prepared using new and used deteriorated lubricating oils of the same type, and the color coordinates of the new and used deteriorated lubricating oils Based on the calibration curve that expresses the correlation of the lubricating oil, the remaining life of the lubricating oil is diagnosed using data from an optical sensor capable of measuring the color coordinates of the lubricating oil. As a result, even if the measurement method is switched from the voltammetry method to optical remote monitoring, the data based on the results of the voltammetry method and the data based on the color coordinates can be mutually converted. As a result, continuity of data can be guaranteed, and highly reliable remaining life diagnosis technology can be provided.

Wind power generators use lubricating oil or the like to reduce the mechanical friction coefficient between components. In the following embodiments, the technology for diagnosing the remaining life of a lubricant will be described using the lubricant for a wind power generator as an example. One example described in the embodiment is a diagnostic system for a wind power generator that collects information from a wind power generator having a speed-up gear and a generator and determines abnormalities in the wind power generator based on the collected information. . In order to monitor the condition of the wind power generator, this system consists of a sensor that outputs the properties of the lubricating oil supplied to the gearbox as sensor information, and a memory unit that stores the reference value determined for each sensor information. have.

<1. Basic configuration of wind power generator>
FIG. 2 shows a general configuration diagram of a downwind-type wind power generator as an example of a machine to be monitored. In FIG. 2, each device arranged in the nacelle 3 is indicated by a dotted line. As shown in FIG. 2, the wind power generator 1 includes blades 5 that rotate with the wind, a hub 4 that supports the blades 5, a nacelle 3, and a tower 2 that supports the nacelle 3 so as to be rotatable in the horizontal plane. .

In the nacelle 3, a main shaft 31 connected to the hub 4 and rotating together with the hub 4, a shrink disk 32 connected to the main shaft 31, a gearbox 33 connected to the main shaft 31 via the shrink disk 32 and increasing the rotational speed, It also has a generator 34 that rotates the rotor at a rotational speed increased by the speed increaser 33 via the coupling 38 to generate electricity.

A portion that transmits the rotational energy of the blades 5 to the generator 34 is called a power transmission section, and includes the main shaft 31, the shrink disk 32, the gearbox 33, and the coupling 38. The gearbox 33 and generator 34 are held on the main frame 35 . One or a plurality of lubricating oil tanks 37 for storing lubricating oil for lubricating the power transmission section are installed on the main frame 35 . A radiator 36 is arranged in the nacelle 3 on the windward side of the nacelle partition wall 30 . Cooling water cooled by the radiator 36 using outside air is circulated through the generator 34 and the gearbox 33 to cool the generator 34 and the gearbox 33 . Although FIG. 2 illustrates a so-called downwind type wind turbine as an example, it goes without saying that the present embodiment can be applied to an upwind type wind turbine.

Lubricating oil is used in many rotating machines in wind power generators. For example, in FIG. 2, lubricating oil is supplied to the main shaft 31, the gearbox 33, the generator 34, and the yaw and pitch bearings (not shown). Blade pitch control changes the pitch angle of the blades according to the wind speed to control the output, while yaw control controls the direction of the nacelle to follow the direction of the wind so that it receives the wind without waste.

In addition to such power transmission units, it is necessary to supply lubricating oil by forced circulation to rotary machines including rotary machines for yaw control and pitch control. Lubricating oil reduces the friction of the rotating parts of rotating machinery and prevents wear and damage of parts and energy loss. However, deterioration of lubricating oil over time leads to a decline in lubricating performance, and contamination due to wear particles, dust, and other contaminants in the lubricating oil increases the coefficient of friction and increases the risk of wind turbine failure.

If a wind power generator breaks down, there will be significant losses, such as the cost of replacing broken parts and a loss of power generation revenue during power outages. there is In particular, gearboxes, which are critical parts, are at increased risk of failure if the performance of the lubricant deteriorates. Therefore, it is important to have a technology that can estimate the remaining life of the lubricant and the time to replace it as early as possible.

<2. Remaining life evaluation method of lubricating oil>
As a method for evaluating the remaining life of lubricating oils, etc., there is a voltammetry method that uses electrochemical reactions of antioxidants to determine the amount of antioxidants remaining in the oil. In this method, all samples are measured using exactly the same volume. As an antioxidant, it contains BHT (tert-ButylHydroxyToluene), which is a phenolic antioxidant, and diphenylamine (DiPhenylAmine, DPA), which is an amine antioxidant, and synthetic oil PAO (polyalphaolefin) as a base oil. A method for evaluating the remaining life of gear oil will be described.

First, using fresh oil, the reaction voltage (reaction potential) of BHT and the current value at that time, and the reaction voltage (reaction potential) of diphenylamine (DPA) and the current value at that time were measured. Each current value was taken as the initial value (100%). The amount of antioxidant remaining in the used oil is obtained by measuring the current value during the BHT reaction and the current value during the diphenylamine reaction when measuring the used oil, and obtaining the relative value (%) to the current value of the new oil. Here, when the threshold value of phenolic antioxidants is 30% of the initial value and the threshold value of amine antioxidants is 40% of the initial value, replacement is recommended when any of the antioxidants reaches the threshold. and

The remaining life evaluation of lubricating oil by the voltammetry method will be further described with reference to FIG. FIG. 3 is an example of the result of analyzing a lubricating oil containing BHT and DPA by the voltammetry method. When the voltage was gradually increased, the DPA reaction current was observed at the potential A, and the BHT reaction current was observed at the potential B.

In Fig. 3, the curve connecting a-b-c-d-e-f is the measurement result of new oil. Also, the curve connecting a-g-h-i-j-k is the measurement result of lubricating oil used for two years. The amount of DPA in fresh oil corresponds to the a-b-c area, and the amount of BHT in the new oil corresponds to the d-e-f area. Each of these is normalized to 100%, and the amount of DPA and BHT in the used oil relative to the amount of DPA and BHT in the new oil is obtained from the area of a-g-h and the area of i-j-k. A remaining amount can be obtained.

FIG. 4 is a graphical representation showing the reduction of the antioxidant BHT with the use of lubricating oil, analyzed by voltammetry.
FIG. 5 is a graphical representation showing the reduction of the antioxidant DPA with the use of lubricating oil, analyzed by voltammetry.

For example, BHT and DPA were 70% and 80%, respectively, in the gear oil (A) used for one year in a machine operated all year round. Since it is known that the amount of antioxidant in this gear oil decreases in proportion to the usage time, as shown in Figs. was predicted to reach Therefore, the remaining life of gear oil (A) was diagnosed as 1.5 years.

However, since there is no on-line sensor that can be measured by voltammetry, the lubricating oil must be sampled from the machine and measured using an analyzer on-site or in the laboratory. For this reason, for example, in offshore wind turbines, it is necessary to stop the operation and collect the lubricating oil by the operator. Even if there is an abnormality in the oil, there is a possibility that it will be overlooked.

On the other hand, lubricating oil is known to become colored due to deterioration such as consumption of additives. For example, there are diagnostic methods based on color, such as the ASTM color scale. There is also an optical sensor capable of outputting the color of lubricating oil as color coordinates such as RGB. By installing an optical sensor in a machine that uses lubricating oil, it is possible to constantly measure the color of the lubricating oil online.

As a result of investigations by the inventors, it was found that there is a correlation between the amount of antioxidant remaining in the gear oil used, determined by the voltammetry method, and the color index of the gear oil used, determined optically.

Below, the concentration of antioxidants in the lubricating oil is measured using a calibration curve created using the remaining amount of antioxidant obtained by the voltammetry method and the chromaticity data obtained based on the measurement data of the optical sensor. I will explain an example.

FIG. 6 is a graph showing the relationship between the antioxidant concentration in lubricating oil obtained by the voltammetry method and the color of the lubricating oil measured by an optical sensor. The lubricating oil color determined by the optical sensor is expressed by a color difference (ΔE) calculated in a color space composed of a combination of RGB.

The definition of ΔE is
ΔE=(R ² +G ² +B ² ) ^1/2
and R, G, B means the three primary colors of light (Red, Green, Blue) in additive mixture, and is expressed as (R, G, B) in numerical representation of color coordinates. Regarding the wavelengths of the three primary colors of light, R is 610 to 750 nm, G is 500 to 560 nm, and B is 435 to 485 nm.

Also, the difference between the maximum and minimum values of R, G, and B is defined as MCD and used for diagnosis in some cases. In general, for lubricating oils,
MCD=RB
is often

Note that RGB chromaticity encoded at 24 bpp (24 bits per pixel, 24 bits per pixel) is represented by three 8-bit integers (0 to 255) representing the luminance of red, green, and blue. For example, (0,0,0) is black, (255,255,255) is white, (255,0,0) is red, (0,255,0) is green, (0,0,255) is blue, respectively. In addition to the RGB color system, there are many other types of chromaticity display such as the XYZ color system, the L ^* a ^* b ^* color system, and the L ^* u ^* v ^* color system. Since it can be converted mathematically and developed into various colorimetric systems, chromaticity may be expressed in other colorimetric systems. If the color of the lubricating oil is quantified by chromaticity, it is possible to display the original color of the lubricating oil on the monitor or display of the computer or monitoring system by converting the chromaticity value.

FIG. 6 is a calibration curve showing the correlation between ΔE of lubricating oil and residual BHT amount (%). The same type of gear oil was used for rated power generation in a 2 MW wind turbine with the same specifications, and the lubricating oils (A, B, and C) sampled periodically were measured by the voltammetry method and color coordinates. There was a high correlation with the residual BHT amount (%) determined by the voltammetry method.

Here, as shown in FIG. 6, the relationship between the antioxidant residual concentration C obtained from voltammetry and the lubricating oil color index (ΔE, B value, MCD, etc.) is expressed by the function can be expressed as a formula
C=f(ΔE) (1)
or,
C=f(B) (2)

Lubricants may contain multiple antioxidants. In this case, a threshold is set for each antioxidant, and the antioxidant that reaches the threshold the earliest is taken as the index for the lubricating oil. The correlation between the residual amount of the antioxidant obtained by the voltammetry method and the color coordinate index obtained by the optical sensor is used as the calibration curve for diagnosing the remaining life of the lubricating oil.

The calibration curve showing the relationship between the measurement results of the voltammetry method and the color coordinates of the lubricating oil is obtained using lubricating oil that has been forcibly oxidatively deteriorated by various oxidation tests known as accelerated deterioration tests of lubricating oils. can also be created. Even if the type and initial concentration of antioxidants are the same, the degree of color change due to aging due to mechanical use may differ if the type of base oil and the type and concentration of other additives are different. . Therefore, it is necessary to create a calibration curve for each oil type that shows the relationship between the degree of deterioration and chromaticity of lubricating oil.

The color of lubricating oil changes due to oxidative deterioration, but it also changes when a large amount of water, fine particles, wear dust, etc. are mixed into the oil. Here, the oxidative deterioration of the lubricating oil is defined as "deterioration", and the phenomenon of external contamination by water, fine particles, wear debris, etc. is defined as "contamination". Regarding such deterioration and contamination, for example, on the graph of ΔE and MCD, which is an index of the color of the lubricating oil, it is possible to determine whether the sample is only deteriorated or not only deteriorated but also contaminated to a certain extent. It is possible to diagnose whether the sample is

For lubricating oil diagnosis, when the above contamination occurs, for example, water contamination causes corrosion and rust of machines, and fine particles and abrasion powder cause damage to gears and bearings. The diagnostic result is that the lubricating oil should be changed and the machine should be inspected. Remaining life diagnosis of lubricating oil is carried out when there is no or slight contamination.

An optical sensor for measuring the properties of lubricating oil is installed on parts that use lubricating oil, such as gearboxes in wind turbines. Using this calibration curve, the remaining amount of antioxidant can be determined, and the remaining life of the lubricating oil can be determined.

In this way, the color of the lubricating oil is detected by an optical sensor installed in the lubricating oil of the gearbox, and based on the color information, the degree of deterioration and contamination of the lubricating oil is determined in real time. Based on the result of the determination, sampling of lubricating oil for detailed lubricating oil analysis is urged at an appropriate timing before the gearbox fails.

The relationship between the color information of the optical sensor and the degree of abnormality in the lubricating oil (impurity concentration, degree of oxidation, etc.), and the relationship between the color of the lubricating oil and the residual amount of antioxidant obtained by the voltammetry method, were experimentally investigated in advance. It is obtained and stored as a database. As a result, failures can be prevented by performing appropriate lubricating oil replacement, filter replacement, or parts replacement. manageable.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention should not be construed as being limited to the descriptions of the embodiments shown below. Those skilled in the art will easily understand that the specific configuration can be changed without departing from the idea or spirit of the present invention.

In the configuration of the invention described below, the same reference numerals may be used in common for the same parts or parts having similar functions in different drawings, and overlapping explanations may be omitted.

When there are multiple elements having the same or similar functions, they may be described with the same reference numerals and different suffixes. However, if there is no need to distinguish between multiple elements, the subscripts may be omitted.

The notations such as "first", "second", "third" in this specification are attached to identify the constituent elements, and do not necessarily limit the number, order, or content thereof do not have. Also, a number for identifying a component is used for each context, and a number used in one context does not necessarily indicate the same configuration in another context. In addition, this does not preclude a component identified by a certain number from also functioning as a component identified by another number.

The position, size, shape, range, etc. of each component shown in the drawings, etc. may not represent the actual position, size, shape, range, etc., in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the positions, sizes, shapes, ranges, etc. disclosed in the drawings and the like.

In the following embodiments, a wind power generator having a gearbox and a power generator, and a wind power generator diagnostic system that collects information from the wind power generator and determines an abnormality in the wind power generator based on the collected information. In the system, when measuring and diagnosing the color of the lubricating oil supplied to the gearbox with a sensor, the correlation between the color information and the residual amount of antioxidant obtained in advance by the voltammetry method is used to An example of accurate sensor diagnosis will be described.

In the embodiment, in order to monitor the lubricating oil supplied to the mechanical drive part of the wind power generator, various sensors, including an optical sensor installed in the lubricating oil of the gearbox, are used to monitor the lubricating oil properties and the rotating machinery. Detects the acceleration of the gearbox to grasp the state, and based on the sensor information (numerical values indicating the physicochemical state of the lubricating oil), determines the degree of abnormality of the lubricating oil and the state of the rotating machine in real time. do.

Then, according to the judgment result, it is a diagnostic system for wind power generators that prompts lubricating oil sampling for detailed lubricating oil analysis, lubricating oil replacement, filter replacement, and parts replacement at the appropriate timing before the gearbox fails. be. The system comprises an input device, a processing device, a storage device and an output device. The storage device stores the relative relationship between the concentration of the antioxidant in the lubricating oil and the chromaticity, which is the data of the optical sensor, which is obtained in advance by the voltammetry method, and the processing device is an optical system that measures the chromaticity of the lubricating oil. Based on the formula sensor data, the time at which the additive concentration in the lubricating oil, which is obtained from the chromaticity characteristics of the lubricating oil, is equal to or lower than a predetermined threshold (reference value) is estimated.

Also, an embodiment is a wind turbine generator diagnostic system and method using an optical lubricating oil sensor, using a server with a processing device, a storage device, an input device, and an output device. In this method, first, in order to grasp the properties of the lubricating oil, the first step is to acquire the chromaticity data of the lubricating oil of the wind power generator, the second step is to measure the concentration of the antioxidant contained in the sample, The third step of storing the measured additive concentrations in time series in a storage device as additive concentration data, the processing device processing the additive concentration data so that the additive concentration reaches a predetermined threshold value. Perform the fourth step of estimating the time.

(1. Overall system configuration)
FIG. 7 shows a schematic diagram of a lubricating oil monitoring system for a wind power generator having a lubricating oil supply system as an example of a machine that performs lubricating oil diagnosis. 7 shows the nacelle 3 of the wind power generator 1 shown in FIG. 2 for the sake of explanation. Inside the nacelle 3 are a main shaft 31 , a gearbox 33 , a generator 34 , and yaw and pitch bearings (not shown), to which lubricant is supplied from a lubricant tank 37 .

As shown in FIG. 7, a plurality of wind power generators 1 are usually installed on the same site, and collectively referred to as a farm 200a. Various sensors (not shown) are installed in the lubricating oil supply system of each wind power generator 1 , and sensor signals reflecting the state of the lubricating oil are collected in a server 210 in the nacelle 3 . Further, sensor signals obtained from the server 210 of each wind power generator 1 are sent to an aggregation server 220 arranged for each farm. Data from aggregation server 220 is sent to central server 240 via network 230 . Data from other farms 200b and 200c are also sent to the central server 240. FIG. Also, the central server 240 can send instructions to each wind power generator 1 via the aggregation server 220 and the server 210 .

(2. Sensor arrangement)
FIG. 8 is a conceptual diagram of a rotary machine equipped with lubricating oil sensors. Lubricating oil is supplied to the rotating machine 302 from a lubricating oil supply device 301 such as a pump. The lubricating oil supply device 301 is connected to the lubricating oil tank 37 and receives lubricating oil. The rotary machine 302 may include, for example, the speed-up gear 33 and other parts where mechanical contact occurs, as well as a power transmission section for performing yaw/pitch control.

A sensor group 304 is arranged in a lubricating oil flow path or the like to detect the state of the lubricating oil. In the first embodiment, a measuring unit 303 is provided in a flow path (branch line) branched from a lubricating oil flow path connected to a lubricating oil drain port of a rotary machine 302, and part of the lubricating oil is supplied to the measuring unit 303. A sensor group 304 is installed in the measurement unit 303 . A branch line is preferably provided near the end of the lubricating oil path in order to monitor the state of deterioration of the lubricating oil. The reason why the measuring section 303 is not provided in the main flow path (circulation line) of the lubricating oil is to adjust the flow velocity of the lubricating oil in the measuring section 303 to a flow velocity suitable for detecting the state of the lubricating oil. In this way, by using branch lines branched from the circulation line and arranged in parallel with the circulation line, and adjusting the bending shape and thickness of the branch line, it is also possible to adjust the hydraulic pressure.

Lubricating oil discharged from the rotary machine 302 returns to the lubricating oil tank 37 via the oil filter 305 . The mesh diameter of the oil filter 305 is 5 to 50 μm.

The expressions "upstream" and "downstream" are sometimes used to express the positional relationship along the lubricating oil flow path. Lubricating oil moves relatively from upstream to downstream. In the case of FIG. 8, the lubricating oil supply device 301 is upstream, the oil filter 305 is downstream, and the measuring part 303 is arranged therebetween. The arrangement of each element is not limited to the configuration shown in FIG. 8, and for example, the lubricating oil tank 37 may be arranged between the rotary machine 302 and the measuring section 303 as described later.

Sensor group 304 measures various parameters of the lubricating oil. For example, physical quantities include temperature, oil pressure, etc., in addition to chromaticity determined by an optical sensor. Instead of or in addition to the optical sensor, a sensor for measuring electrical properties such as permittivity and conductivity of lubricating oil may be provided. Temperature, oil pressure, etc. can be measured using known sensors. The condition of the lubricating oil can be evaluated based on changes in these parameters over time. Although these sensors for temperature and the like are not essential, they are preferably provided in order to detect the condition of the lubricating oil in more detail.

In an embodiment, sensor cluster 304 includes an optical sensor with a visible light source and a light receiving element. The optical sensor measures the visible light transmittance of the lubricating oil and outputs chromaticity information (R, G, B values) of the lubricating oil. Based on the obtained chromaticity data, the amount of residual additives in the lubricating oil is determined, and the degree of deterioration and remaining life are diagnosed. Diagnosis based on sensor data is performed based on sensor data from an optical sensor or optical sensor and other one or more types of sensor data.

Lubricating oils degrade in quality due to consumption of antioxidants through use, and cease to perform their initial functions. For this reason, it is necessary to perform maintenance such as replacement according to the state of deterioration of quality. In order to know the timing of such maintenance, it is useful for efficient maintenance and management to be able to remotely monitor the data that can be collected by the sensor group 304 . The data collected by the sensor group 304 is collected by the server 210 in the nacelle 3, for example, and then sent to the central server 240 that aggregates the data of multiple farms via the aggregation server 220 that aggregates the data within the farm 200.

Data to be aggregated may include not only data related to lubricating oil but also data indicating the operation status of the wind power generator. For example, an acceleration sensor that detects the vibration of the wind power generator 1 (the larger the value, the faster the deterioration rate of the lubricant), the wind turbine output value (the larger the value, the faster the deterioration rate of the lubricant), the actual operation time (the longer the value, the faster the deterioration rate of the lubricant). ), machine temperature (the higher the temperature, the faster the deterioration rate of the lubricating oil), the rotational speed of the shaft (the faster the speed, the faster the deterioration rate of the lubricating oil), and the temperature of the lubricating oil (the higher the temperature, the faster the deterioration rate of the lubricating oil). These can be collected from sensors of known configuration installed at various locations in the wind power generator and control signals of the device.

(3. Lubricant diagnosis flow)
FIG. 9 is a flowchart showing lubricating oil diagnosis processing according to the embodiment. The processing shown in FIG. 9 is performed under the control of any one of the server 210, aggregation server 220, and central server 240 in FIG. In the following example, it is assumed that the central server 240 does this. Functions such as calculation and control are realized by cooperating with other hardware by executing software stored in the storage device of the server by the processor. It should be noted that functions equivalent to those configured by software can also be realized by hardware such as FPGAs (Field Programmable Gate Arrays) and ASICs (Application Specific Integrated Circuits).

When the central server 240 performs control, since it has a plurality of wind power generators 1 under its control, the following processing shall be performed for each wind power generator. This process is basically a repetitive process, and the start timing is set by a timer or the like. For example, the process starts at 00:00 every day (S601). Also, the central server 240 can perform this at an arbitrary timing according to an operator's instruction.

In processing S602, the central server 240 checks the lubricating oil replacement timing. As for the initial value of the replacement timing, the remaining life is initially set on the premise that the lubricating oil is operating at the design temperature, for example. This replacement timing can be updated later in step S610 based on actual measurement data.

If it is time to replace the lubricating oil, the lubricating oil is replaced in step S603. Since lubricating oil replacement is usually performed by a worker, the central server 240 displays and notifies the worker about when and what to replace.

If it is not time to replace the lubricating oil, the central server 240 diagnoses the properties of the lubricating oil based on sensor data in step S604. As sensor data, temperature, oil pressure, concentration of particles contained in lubricating oil, etc. can be used in addition to chromaticity information of lubricating oil obtained by an optical sensor. The data measured by the sensors 304 are sent to a central server 240, which, for example, evaluates the lubricating oil properties by comparing the parameters obtained from the sensors with predetermined reference values. The central server stores the correlation between chromaticity and antioxidant concentration determined by the voltammetry method, as shown in Figure 6, and the consumption of antioxidants in lubricating oil (additives decompose to produce oxidation products). The change in each value of R, G, and B at the time of wear, and the change in each value of R, G, and B when abrasion powder is generated in the lubricating oil are stored in advance and used for comparison with sensor data. and For this reference value, in addition to a predetermined threshold value, a predetermined amount of change in sensor information per unit time can be used.

FIG. 10 shows programs and data structures stored by the central server 240 . The central server 240 comprises an input device 1001, an output device 1002, a processing device 1003 and a storage device 1004 like a general server. FIG. 10 shows programs and data configurations stored in the storage device 1004 .

The storage device 1004 of the central server 240 stores the correlation between the chromaticity (ΔE and B) and the antioxidant concentration obtained by the voltammetry method, which is experimentally obtained in advance and stored. A measured antioxidant concentration DB 242 of lubricating oil of an actual machine (for example, a wind power generator) and a chromaticity DB 243 in which sensor data acquired by an optical sensor are stored in chronological order are stored as data.

The correlation DB 241 may store, for example, the functions represented by formulas (1) and (2), or the data shown in FIG. The data conversion program 244 can use the information stored in the correlation DB 241 to convert the data in the chromaticity DB 243 into an antioxidant concentration determined by the voltammetry method. Since the conversion data 245 obtained by the data conversion program 244 has continuity with the data in the antioxidant concentration DB 242, two different measurement methods can be used as a continuous series of time-series data.

The storage device 1004 also has a diagnostic program 246 that controls the entire lubricating oil diagnostic process shown in FIG.

Returning to FIG. 9, if the diagnosis result is abnormal in steps S605 and S606, the lubricating oil is replaced in step S603. Specifically, the lubricating oil is replaced by notifying the person in charge of managing the lubricating oil replacement that the replacement is necessary. If there is no abnormality, processing S609 is performed.

In step S605, for example, if all the R, G, and B values of the optical sensor are lower than a predetermined threshold value, it is determined that there is a contamination abnormality. Such determination detects the blackening of the lubricating oil. However, for contamination anomalies, conventional sensor data may also be used.

In S606, for example, using the correlation between the additive concentration and the chromaticity shown in FIG. 6, if the additive concentration obtained from the chromaticity measured by the optical sensor falls below a predetermined threshold, the additive deterioration degree is abnormal. I judge. It should be noted that it is also possible to determine that there is an abnormality in the degree of deterioration of the additive when the chromaticity is smaller than a predetermined threshold, without obtaining the additive concentration from the chromaticity.

In step S609, chromaticity measurement data and the like are input to the central server 240, and the chromaticity measurement data are stored in the chromaticity DB 243 in chronological order.

From the perspective of preventive maintenance and planned maintenance of wind power generators, predictive diagnosis of deterioration of lubricating oil based on changes in the concentration of antioxidants contained in lubricating oil is performed before it is determined that there is an abnormality. is desirable.

As described above, using the antioxidant concentration measurement results obtained by the voltammetry method and the color information of the lubricating oil measured by the optical sensor, it is possible to obtain chronological data on the normality of the lubricating oil. Knowing the remaining service life enables early detection of the service life of the lubricating oil. Therefore, maintenance such as proper replacement of lubricating oil can prevent malfunction of the wind power generator. It is also possible to optimize the lubricating oil replacement cycle. In addition, the antioxidant concentration can be measured by a simple method, and if an optical sensor is installed in the nacelle, it becomes possible to remotely monitor the consumption of the antioxidant in the lubricating oil online.

(4. Remaining life diagnosis of lubricating oil)
In this embodiment, in the replacement timing estimation and update processing S610 in FIG. Based on the information obtained from the correlation between the concentration of antioxidants and the color coordinates, the antioxidant concentration was obtained from the color measurement of the lubricating oil, and the remaining life of the lubricating oil was obtained. Give an example.

Regarding lubricating oil of the same model number, we obtained new oil (A), a sample (B) that had been used in a wind turbine for one year, a sample (C) that had been used for two years, and a sample (D) that had been used for three years.

This lubricating oil contains a phenol antioxidant BHT and an amine antioxidant DPH. As shown in FIGS. 11 and 12, it was confirmed by the voltammetry method that samples (A) to (D) tended to decrease in antioxidant content over time.

As shown in FIG. 11, for this lubricating oil, 20% of the concentration of new oil is set as a threshold for BHT.
As shown in FIG. 12, for DPA, 40% of the concentration of new oil is set as a threshold. An oil change was to be recommended if either BHT or DPA fell below thresholds. That is, the service life of the lubricating oil is from the start of use until the concentration of either BHT or DPA reaches a threshold value.

From Figures 11 and 12, BHT reached the threshold at 3 years, DPA did not reach the threshold at 3 years, and by linear approximation of the trend, reached the threshold at 4 years. It has been found. Therefore, it was found that this lubricating oil should be monitored for BHT, which is consumed faster than DPA.

On the other hand, samples (A) to (D) were subjected to color measurement using an optical sensor disclosed in Patent Document 1, for example. At this time, the color coordinates of fresh oil (A) were normalized to (255, 255, 255). A ΔE value was obtained from each color coordinate.

Figure 13 shows the antioxidant quantification result (first result) obtained by electrochemical measurement (voltammetry method) and the lubricating oil diagnosis result (second result) obtained by optical measurement obtained in advance. Also, it is a graph showing the relationship between the ΔE value and the residual antioxidant concentration C based on the correlation function (for example, the relationship of formula (1)) between the first result and the second result. As shown in FIG. 13, the relationship between BHT concentration and ΔE value was clarified.

From FIG. 13, it was found that the ΔE value was 200 when the BHT was 20% of the new oil value. Thus, it was found that by using FIG. 13 as a calibration curve, the concentration of the antioxidant obtained by voltammetry can be obtained from the color coordinates of the lubricating oil measured by the optical sensor. For example, the calibration curve shown in FIG. 13 is stored in the correlation DB 241 of FIG.

In this way, by using the correlation DB 241, in the process S610, data based on the antioxidant quantification result (first result) obtained by the electrochemical measurement (voltammetry method) obtained in advance using the correlation DB 241 , compatibility can be given to data based on lubricating oil diagnosis results (second results) obtained by optical measurement.

In this example, lubricating oil was sampled from the wind turbine gearbox, and the color of the lubricating oil was measured using an optical sensor outside the wind turbine. An example of obtaining the antioxidant concentration from the color of the lubricating oil using the formulas (1) and (2) that express the correlation between the color and the color is shown below. This lubricating oil contained only the amine antioxidant DPA.

FIG. 14 shows the relationship between the DPA concentration in five lubricating oil samples forcibly degraded by the oxidation test and the color index ΔE of the five lubricating oil samples. In this lubricating oil, replacement of the lubricating oil is recommended when the concentration of the amine-based antioxidant DPA becomes 30% or less. From FIG. 14, the DPA concentration becomes 30% or less when ΔE is 150 or less.

FIG. 15 is a graph showing the principle of remaining life diagnosis of the embodiment. In this embodiment, data 1502 is obtained by measuring the DPA concentration by the voltammetry method during the period 1501 from new oil to 2 years after the windmill. In the second to fourth years, the color of the lubricating oil is measured using an optical sensor, the color information is converted by the data conversion program 244 using the correlation DB 241, and the almost real-time DPA concentration 1503 can be obtained. can. As shown in FIG. 15, from the data 1502 and the DPA concentration 1503, using well-known techniques such as function approximation and extrapolation, the remaining life 1504 until the DPA concentration falls below 30% of the initial value is 0.5 years. can be expected to exist.

The determined remaining life is displayed to the user, for example, on a display in step S611. Further, in step S612, the output of the optical sensor may be converted into a color corresponding to the color information of the lubricating oil and displayed.

In FIG. 15, the color information data based on the optical sensor is converted into the additive concentration based on the voltammetry method. Conversely, using the calibration curve of FIG. 6, the additive concentration based on the voltammetry method can also be converted into color information data based on the optical sensor.

FIG. 16 shows data 1602 obtained by measuring the DPA concentration by the voltammetry method during a period 1501 from new oil to 2 years after the wind turbine is used, and converting the DPA concentration to ΔE. In years 2-4, optical sensors can be used to measure lubricant color to provide near real-time delta E data 1603 .

As described above, in this embodiment, the data obtained by the voltammetry method and the data based on the color information obtained by the optical measurement method can be mutually converted. monitoring becomes possible. Therefore, more accurate remaining life diagnosis can be performed based on the data indicating temporal changes in lubricating oil properties.

In the above embodiments, wind power generators were used as examples of rotary machines, but nuclear power generators, thermal power generators, geared motors, railway vehicle wheel flanges, air compressors, transformers, mobile plant machines, large pump machines, etc. This embodiment can also be applied to diagnosis of deterioration of additives in lubricating oil of rotating machines.

In addition, the remaining life diagnosis of the lubricating oil according to this embodiment can be applied to remote monitoring by installing an optical sensor in the lubricating oil in the machine. It is also possible to perform measurement using an optical sensor. Furthermore, the optical sensor can be replaced by a device capable of measuring the color coordinates of the lubricating oil.

Central server 240, input device 1001, output device 1002, processing device 1003, storage device 1004, correlation database DB 241, antioxidant concentration DB 242, chromaticity DB 243, data conversion program 244, conversion data 245, diagnostic program

Claims (15)

A method of diagnosing a lubricating oil containing additives used in machinery, comprising:
Based on the first result that is the result of electrochemical measurement separately obtained in advance and the second result that is the result of optical measurement separately obtained in advance, the first result and the second result Prepare information indicating the relationship,
Based on said information, first data based on electrochemical measurement of the lubricating oil containing additives used in said machine and optical measurement of lubricating oil containing additives used in said machine characterized in that the second data based on the results measured in can be converted,
Lubricant diagnostic method. The additive is
One or more antioxidants selected from phenolic antioxidants, amine antioxidants, phosphorus antioxidants, ZDDP,
The method for diagnosing lubricating oil according to claim 1 . The optical measurement is
It is an optical measurement that determines the color coordinates of the lubricant from the light transmittance of the lubricant,
The method for diagnosing a lubricating oil according to claim 1. As the second result,
Characterized by using the color coordinate B value or ΔE value of the lubricating oil,
The method for diagnosing a lubricating oil according to claim 1. Information indicating the relationship between the first result and the second result is stored in advance as correlation data,
As the first data, an additive quantification result obtained by electrochemical measurement is obtained,
As the second data, a lubricating oil diagnosis result obtained by optical measurement is obtained,
Based on the correlation data, converting the first data into a lubricating oil diagnosis result to obtain third data, and converting the second data into an additive quantification result to obtain fourth data perform at least one of
At least obtaining time-series data using both the first data and the fourth data, and obtaining time-series data using both the second data and the third data run one,
The method for diagnosing a lubricating oil according to claim 1. A diagnostic device for lubricating oils containing additives used in machinery, comprising:
Based on the first result that is the result of electrochemical measurement separately obtained in advance and the second result that is the result of optical measurement separately obtained in advance, the first result and the second result a correlation database that records information indicating relationships;
Based on said information, first data based on electrochemical measurement of the lubricating oil containing additives used in said machine and optical measurement of lubricating oil containing additives used in said machine and a data conversion unit that converts the second data based on the result measured by
Lubricant diagnostic equipment. The additive is
One or more antioxidants selected from phenolic antioxidants, amine antioxidants, phosphorus antioxidants, ZDDP,
The lubricating oil diagnostic device according to claim 6 . The optical measurement is
It is an optical measurement that determines the color coordinates of the lubricant from the light transmittance of the lubricant,
The lubricating oil diagnosis device according to claim 6. As the second result,
Characterized by using the color coordinate B value or ΔE value of the lubricating oil,
The lubricating oil diagnosis device according to claim 6. The first data is the additive quantification result obtained by electrochemical measurement,
The second data is a lubricating oil diagnosis result obtained by optical measurement,
The data conversion unit converts the first data into lubricating oil diagnosis results to obtain third data based on the correlation database, and converts the second data into additive quantification results. obtaining fourth data by performing at least one of
Furthermore, obtaining time-series data using both the first data and the fourth data, and obtaining time-series data using both the second data and the third data, has a diagnostic unit that performs at least one of
The lubricating oil diagnosis device according to claim 6. A diagnostic system for lubricating oils containing additives used in machinery, comprising:
an optical sensor that acquires color information of the lubricating oil;
an additive concentration database that stores additive quantification results obtained by electrochemical measurement of the amount of additives in the lubricating oil;
a data conversion unit that derives the amount of the additive from the color information;
comprising a correlation database referenced by the data conversion unit;
The correlation database is
Information indicating the relationship between the first result, which is the additive quantitative result obtained by electrochemical measurement in advance, and the second result, which is the color information of the lubricating oil obtained in advance by optical measurement,
Lubricant diagnostic system. The additive is
One or more antioxidants selected from phenolic antioxidants, amine antioxidants, phosphorus antioxidants, ZDDP,
The lubricating oil diagnostic system of claim 11 . The optical sensor is
It is characterized by being an optical sensor that obtains the color coordinates of the lubricating oil from the light transmitted through the lubricating oil used in the machine.
The lubricating oil diagnostic system of claim 11 . As the second result,
Characterized by using the color coordinate B value or ΔE value of the lubricating oil,
The lubricating oil diagnostic system of claim 11 . The data conversion unit converts the color information acquired by the optical sensor into an additive quantification result by referring to the correlation database,
Obtaining time-series data on the amount of additive by using the additive quantification result stored in the additive concentration database and the additive quantification result converted by the data conversion unit,
The lubricating oil diagnostic system of claim 11 .

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