An oil filter life prediction device and method based on linear fitting

Abstract

The application belongs to the field of filter element detection, and particularly relates to an oil filter element life prediction device and method based on linear fitting, which is used to solve the problem that the service life of a filter element is difficult to be accurately grasped when the filter is used, and comprises a differential pressure sensor, a temperature sensor, a clock, a single-chip microcomputer and an erasable programmable read-only memory, the differential pressure sensor, the temperature sensor, the clock and the erasable programmable read-only memory are electrically connected with the single-chip microcomputer; the clock periodically sends an interrupt instruction to the single-chip microcomputer, and then resets and re-timing; the single-chip microcomputer receives the interrupt instruction, reads the differential pressure data and the temperature data, and stores the time, the differential pressure data and the temperature data to the erasable programmable read-only memory; when the differential pressure of the filter element reaches a rapid rising stage, the single-chip microcomputer fits a filter element life curve to predict the filter element life. The application has the advantages of accurately predicting the service life of the filter element and timely replacing the filter element.

Description

Technical Field

[0001] This application belongs to the field of filter element testing, and more specifically, relates to a device and method for predicting the life of oil filter elements based on linear fitting. Background Technology

[0002] Filters are commonly used components in industrial production and processing. Filter cartridges are an important part of filters, and their function is to remove solid impurities from the media to ensure the normal operation of the equipment. Filter efficiency and dust holding capacity are the main indicators for judging the performance of filter cartridges. Filter cartridges are consumables and need to be replaced after a period of use to ensure the normal operation of the equipment.

[0003] Wind power is one of my country's important energy sources. The normal operation of wind turbines requires a large amount of lubricating oil, and lubricating oil contamination is one of the main factors causing wind turbine malfunctions and downtime, contributing to 70-80% of wind turbine gearbox failures. Therefore, equipping wind turbines with high-precision filters is the primary means of controlling lubricating oil contamination.

[0004] When using existing filters, the maintenance and replacement of filter elements usually rely solely on the experience of the staff, making it difficult to accurately determine the lifespan of the filter elements. Filter elements are often replaced too early or too late. Replacing the filter elements too early will result in waste and increased costs, while replacing the filter elements too late will lead to a decrease in filtration efficiency and affect the normal operation of the wind turbine. Summary of the Invention

[0005] In order to more accurately predict the service life of filter elements and replace them in a timely manner, this application provides an oil filter element life prediction device and method based on linear fitting.

[0006] The oil filter element life prediction device based on linear fitting provided in this application adopts the following technical solution: An oil filter cartridge life prediction device based on linear fitting includes a differential pressure sensor, a temperature sensor, a clock, a single-chip microcomputer, and an erasable programmable read-only memory. The differential pressure sensor, temperature sensor, clock, and erasable programmable read-only memory are all electrically connected to the single-chip microcomputer. The clock is used to periodically send interrupt commands to the single-chip microcomputer, and then reset to restart the timing. After receiving the interrupt command, the single-chip microcomputer reads the differential pressure data and temperature data, and stores the time, differential pressure data and temperature data into an erasable programmable read-only memory; When the pressure difference of the filter element reaches a rapidly increasing stage, a single microcomputer fits the filter element life curve to predict the filter element life.

[0007] As a further preferred embodiment, the single-chip microcomputer corrects the pressure difference data based on the read temperature data, and the correction formula is as follows:

[0008] In the formula: △P 修正i For the corrected differential pressure data of the i-th measurement, ΔP 实测i The differential pressure data is the actual measured differential pressure data of the differential pressure sensor for the i-th time; T0 is the specified operating temperature, T i Here, f(T0) is the actual temperature measured by the temperature sensor, and f(T0) is the viscosity of the oil at temperature T0. i ) represents the oil in T i Viscosity at temperature; The relationship between oil viscosity and temperature conforms to the following formula: lnv=lnA+Blnt In the formula: v is the viscosity of the oil, A is the characteristic coefficient of the oil, B is the characteristic coefficient of the oil, and t is the temperature.

[0009] As a further preferred embodiment, the single-chip microcomputer calculates the difference between two consecutive corrected differential pressure data as the differential pressure rise per unit time, and saves the data in an erasable programmable read-only memory. The formula for calculating the differential pressure rise within the time interval Δt0 is:

[0010] In the formula, △P 上升i Let ΔP be the increase in pressure difference during the time interval Δt0 during the i-th pressure difference measurement. 修正i This is the corrected differential pressure data from the i-th measurement.

[0011] As a further preferred embodiment, the single-chip microcomputer calculates the average value of the pressure difference increase over time Δt0 based on the pressure difference increase value, and uses this as a parameter for the filter element's pressure difference smooth rise characteristic.

[0012] In the formula, △P 平缓 ΔP is a characteristic parameter when the filter element pressure differential rises gradually. 上升i This is the corrected differential pressure data from the i-th measurement, where i is the number of measurements. When calculating the pressure difference of the i-th measurement, compare ΔP 上升i With △P 平缓 The relationship when △P 上升i Greater than △P 平缓 When the pressure difference is three times that of the filter element, it is considered to be in a phase of rapid increase.

[0013] As a further preferred embodiment, the single-chip microcomputer continuously records at least m ΔP values. 上升 , calculate △P 上升i , △P上升i+1 , …… △P 上升i+m-1 When the increase in these pressure differences is greater than ΔP 平缓 When the pressure difference is 3 times that of the filter element, it is considered to be in a rapid rising phase, and m is 5% of the total sample size.

[0014] As a further preferred embodiment, after the filter element pressure difference reaches the rapid increase stage, the single-chip microcomputer fits the filter element life curve, and the curve equation is:

[0015] in Let i be the filter cartridge running time during the i-th measurement. ; This is the correction amount for the filter element pressure difference value during the i-th measurement; the coefficients a, b, c, d, e, and f are automatically derived by a single-chip microcomputer based on the curve. Based on the curve equation, a single-chip microcomputer predicts the future V. i The pressure difference of the filter element at a given time point;

[0016] when and hour, The corresponding time is the predicted lifespan of the filter element, where To replace the filter element with the required differential pressure as per design specifications, The future calculated by the single-chip microcomputer (4) based on the curve Predicted pressure difference over time.

[0017] As a further preferred embodiment, the single-chip microcomputer is connected to a display screen, which records the corrected differential pressure data and time data on a two-dimensional coordinate system and displays a matrix of differential pressure changes over time on the display screen.

[0018] As a further preferred embodiment, the single-chip microcomputer is also equipped with a reset button. After replacing the filter element, clicking the reset button will clear the data in the erasable programmable read-only memory of the single-chip microcomputer, reset the device, and allow the measurement data to be collected again.

[0019] As a further preferred embodiment, the clock is the internal clock of the single-chip microcomputer.

[0020] The oil filter element life prediction method based on linear fitting provided in this application adopts the following technical solution: A method for predicting the life of an oil filter element based on linear fitting, using a prediction device, includes the following steps: S1: The differential pressure, temperature and time of the filter element operation are measured by a differential pressure sensor, a temperature sensor and a clock. A single-chip microcomputer processes the data and stores it in an erasable programmable read-only memory. S2: A single-chip microcomputer uses temperature data to correct the pressure difference data; S3: Analyze whether the filter element has reached the stage of rapid increase in differential pressure based on the corrected differential pressure data. If it has not reached the stage, repeat S1 and S2. If it has reached the stage, proceed to the next step. S4: Fitting the filter cartridge life curve; S5: Predict the filter life based on the filter life curve.

[0021] In summary, this application includes at least the following beneficial technical effects: 1. Based on the pressure difference and temperature data of the filter element during on-site operation, the service life of the filter element can be predicted. The predicted service life is based on the on-site operation pattern and the pressure difference rise curve of the filter element, which can accurately predict the service life of the filter element so that the filter element can be replaced in time after the filter has been used for a period of time, thus ensuring the filter's performance. 2. To address the issue of oil temperature affecting pressure differential in industrial settings, the pressure differential is corrected using measured temperature to avoid long-term fluctuations in operating temperature affecting lifespan prediction and improve prediction accuracy; 3. By recording the corrected differential pressure data multiple times, the system flow fluctuations in the filter element system can be avoided. A sudden increase in the measured differential pressure data in a short period of time could be misjudged as the differential pressure of the filter element reaching a rapid increase stage, thus reducing the possibility of misjudgment. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the method of an embodiment of this application; Figure 2 This is a structural diagram of the device according to an embodiment of this application; Figure 3 This is a lifespan prediction curve for a certain filter element.

[0023] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1. Differential pressure sensor; 2. Temperature sensor; 3. Clock; 4. Single-chip microcomputer; 5. Erasable programmable read-only memory; 6. Display screen. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0025] The following is in conjunction with the appendix Figure 1-3This application will be described in further detail.

[0026] This application discloses an oil filter element life prediction device based on linear fitting.

[0027] Reference Figure 1 A device for predicting the lifespan of an oil filter element based on linear fitting includes a differential pressure sensor 1, a temperature sensor 2, a clock 3, a single-chip microcomputer 4, and an erasable programmable read-only memory 5. The differential pressure sensor 1, temperature sensor 2, clock 3, and erasable programmable read-only memory 5 are all electrically connected to the single-chip microcomputer 4. The differential pressure sensor 1, temperature sensor 2, and clock 3 transmit data to the single-chip microcomputer 4. The single-chip microcomputer 4 processes the data and stores it in the erasable programmable read-only memory 5.

[0028] In this embodiment, the preferred parameters of the differential pressure sensor 1 are: differential pressure measurement range of 0 to 0.5 MPa, measurement accuracy of 0.5%, and output signal as IIC digital signal; The preferred parameters for temperature sensor 2 are: differential pressure measurement range -20 to 85°C, measurement accuracy 1%, and output signal is IIC digital signal; The single-chip microcomputer 4 uses an STM32 microcontroller. The STM32 microcontroller has two IIC input interfaces and one UART output interface. The differential pressure sensor 1 and the temperature sensor 2 are connected to their respective IIC input interfaces. The erasable programmable read-only memory 5 is connected to the UART output interface. The erasable programmable read-only memory 5 has a memory of not less than 2MB; The clock 3 can be the internal clock 3 of the single-chip microcomputer 4 or an external clock 3. In this embodiment, the clock 3 is preferably the internal clock 3 of the single-chip microcomputer 4, so as to send interrupt instructions to the single-chip microcomputer 4. The single-chip microcomputer 4 is also equipped with a reset button. After the filter element is replaced, clicking the reset button will clear the data in the erasable programmable read-only memory 5 of the single-chip microcomputer 4, reset the device, and enable the measurement data to be re-entered.

[0029] The single-chip microcomputer 4 converts the electrical signal from the differential pressure sensor 1 into differential pressure data; The single-chip microcomputer 4 converts the electrical signal from the temperature sensor 2 into temperature data; The single-chip microcomputer 4 converts the time measured by the clock 3 into time data; The single-chip microcomputer 4 stores the differential pressure data, temperature data, and time data recorded at the same time as a group of data in the erasable programmable read-only memory 5, forming a dynamically long array.

[0030] The microcomputer 4 calls the internal clock 3 to keep track of time, and records data once every certain time interval Δt0. In this embodiment, the microcomputer 4 reads the data in the erasable programmable read-only memory 5 once every 12 hours, and sets 12 hours as the cycle of the clock 3. Every 12 hours, the clock 3 sends an interrupt command to the microcomputer 4, and then resets and starts timing again. After receiving the interrupt command from the internal clock 3, the microcomputer 4 reads the pressure difference data and temperature data once, and stores the time, pressure difference and temperature data in the erasable programmable read-only memory 5.

[0031] In actual operation of filters and filter elements, oil temperature will change with the ambient temperature. Although the system oil temperature is between 40 and 80°C due to the high temperatures generated by the equipment operation and the heat dissipation effect of the cooling device, the actual temperature difference between day and night is generally large throughout the four seasons, resulting in significantly higher temperatures in summer than in winter, and significantly higher temperatures at noon than at night. The pressure differential of the filter element is directly proportional to the viscosity of the oil, and the viscosity of the oil decreases as the temperature rises. The lifespan of the filter element is mainly affected by the amount of contaminants intercepted by the filter element, which is directly reflected in the pressure differential of the filter element. Therefore, it is necessary to correct the oil pressure differential based on the operating temperature to avoid the pressure differential changes caused by uneven day and night temperatures being mistakenly interpreted as changes in filter element lifespan.

[0032] The pressure difference data is corrected using temperature data, and the correction formula is as follows:

[0033] In the formula: △P 修正i For the corrected differential pressure data of the i-th measurement, ΔP 实测i The differential pressure data is the actual measured differential pressure data of the differential pressure sensor for the i-th time; T0 is the specified operating temperature, T i Here, f(T0) is the actual temperature measured by the temperature sensor, and f(T0) is the viscosity of the oil at temperature T0. i ) represents the oil in T i Viscosity at temperature. Since different types of oils have different viscosity-temperature profiles, the relationship between viscosity and temperature needs to be determined experimentally. The relationship between f(T) and T is determined experimentally. Generally speaking, the relationship between oil viscosity and temperature conforms to the following formula: lnv=lnA+Blnt In the formula: v is the viscosity of the oil, A is the characteristic coefficient of the oil, B is the characteristic coefficient of the oil, and t is the temperature; For example, the viscosity-temperature relationship table for VG-XX lubricating oil:

[0034] The difference between two consecutive corrected differential pressure data points is calculated as the increase in differential pressure per unit time, and this data is stored in an erasable programmable read-only memory. The formula for calculating the increase in differential pressure within time Δt0 is:

[0035] In the formula, △P 上升i Let ΔP be the increase in pressure difference during the time interval Δt0 during the i-th pressure difference measurement. 修正i This is the corrected differential pressure data from the i-th measurement.

[0036] Calculate the average increase in pressure difference over time Δt0, and use it as a parameter to describe the gradual increase in pressure difference of the filter element.

[0037] In the formula, △P 平缓 ΔP is a characteristic parameter when the filter element pressure differential rises gradually. 上升i This is the corrected differential pressure data from the i-th measurement, where i is the number of measurements.

[0038] When calculating the pressure difference of the i-th measurement, compare ΔP 上升i With △P 平缓 The relationship when △P 上升i Greater than △P 平缓 When the pressure difference of the filter element is three times that of the filter element, it is considered to be in a rapid rising phase. Specifically, to avoid flow fluctuations in the system where the filter element is located, ΔP should be adjusted within a short period of time. 上升i A sudden increase was mistakenly interpreted as the filter element pressure differential reaching a rapid increase phase. At least m consecutive records of ΔP can be made. 上升 , calculate △P 上升i , △P 上升i+1 , …… △P 上升i+m-1 When the increase in these pressure differences is greater than ΔP 平缓 When the pressure difference is three times that of the filter element, it is considered to be in a rapid increase phase. The constant m is determined based on the flow stability of the system in which the filter is located. Generally speaking, due to the influence of factors such as the accuracy of the differential pressure sensor, the stability of the system in which the filter is located, and sudden changes during data reading, the recorded ΔP may jump. By increasing the sample size m for comparison, the analysis error can be avoided due to the distortion of a certain data sample, which is an error-proofing design. Increasing the sample size m for comparison can reduce the possibility of misjudgment. Typically, the comparison sample size m is set to about 5% of the total sample size. In this embodiment, the sample size m was recorded five times, and the pressure difference increase was ΔP for all five consecutive times. 上升i Greater than △P 平缓 When the pressure difference is three times that of the filter element, it is considered to be in a phase of rapid increase.

[0039] The single-chip microcomputer 4 is also connected to a display screen 6. The single-chip microcomputer 4 records the corrected differential pressure data and time data on a two-dimensional coordinate system, and displays the pressure difference changing over time on the display screen 6. When the filter element pressure difference reaches the rapid increase stage, the single-chip microcomputer 4 uses the least squares method to solve for the filter element life curve parameters and fits the filter element life curve. The curve equation is:

[0040] in Let i be the filter cartridge running time during the i-th measurement. ; This is the correction amount for the filter element pressure difference value during the i-th measurement; the coefficients a, b, c, d, e, and f are automatically derived by the single-chip microcomputer 4 based on the curve.

[0041] Based on the curve equation, the single-chip microcomputer 4 predicts the future V. i The pressure difference of the filter element at a given time point.

[0042]

[0043] when and hour, The corresponding time is the predicted lifespan of the filter element, where To replace the filter element with the required differential pressure as per design specifications, The future calculated by the single-chip microcomputer (4) based on the curve Predicted pressure difference over time.

[0044] Display screen 6 shows the remaining lifespan of the filter cartridge:

[0045] In the formula, To predict remaining lifespan, To predict lifespan, This indicates the time the filter element has been used.

[0046] This application also discloses a method for predicting the lifespan of oil filter elements based on linear fitting.

[0047] A method for predicting the life of an oil filter element based on linear fitting, using a prediction device, includes the following steps: S1: After installing the filter element, click the reset button to reset the device. The differential pressure sensor 1, temperature sensor 2 and clock 3 measure the differential pressure, temperature and time of the filter element's operation. The single-chip microcomputer 4 processes the data and stores it in the erasable programmable read-only memory 5. The clock 3 periodically sends an interrupt command to the single-chip microcomputer 4. After receiving the interrupt command from the internal clock 3, the single-chip microcomputer 4 reads the differential pressure data and temperature data once, and stores the time, differential pressure and temperature data in the erasable programmable read-only memory 5. S2: The single-chip microcomputer 4 uses temperature data to correct the pressure difference data; S3: Calculate the pressure difference increase per unit time based on two adjacent corrected pressure difference data, and calculate the average pressure difference increase. Record the data multiple times, with the number of records being 5% of the total sample size. Analyze whether the filter element has reached the stage of rapid pressure difference increase. If it has not reached the stage, repeat S1 and S2. If it has reached the stage, proceed to the next step. S4: A single-chip microcomputer automatically fits the filter life curve; S5: Single-chip microcomputer 4 predicts filter life based on filter life curve.

[0048] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A device for predicting the lifespan of an oil filter element based on linear fitting, characterized in that: It includes a differential pressure sensor (1), a temperature sensor (2), a clock (3), a single-chip microcomputer (4), and an erasable programmable read-only memory (5), wherein the differential pressure sensor (1), the temperature sensor (2), the clock (3), and the erasable programmable read-only memory (5) are all electrically connected to the single-chip microcomputer (4); The clock (3) is used to periodically send interrupt commands to the single-chip microcomputer (4) and then reset and restart the timing; After receiving the interrupt command, the single-chip microcomputer (4) reads the differential pressure data and temperature data, and stores the time, differential pressure data and temperature data into the erasable programmable read-only memory (5); When the pressure difference of the filter element reaches the stage of rapid increase, the single-chip microcomputer (4) fits the filter element life curve to predict the filter element life. The single-chip microcomputer (4) corrects the pressure difference data based on the read temperature data, and the correction formula is as follows: In the formula: △P 修正i For the corrected differential pressure data of the i-th measurement, ΔP 实测i The differential pressure data is the actual measured differential pressure data of the differential pressure sensor (1) for the i-th time; T0 is the specified operating temperature, T i The actual temperature measured by temperature sensor (2), f(T0) is the viscosity of the oil at temperature T0, f(T i ) represents the oil in T i Viscosity at temperature; The relationship between oil viscosity and temperature conforms to the following formula: lnv=lnA+Blnt In the formula: v is the viscosity of the oil, A is the characteristic coefficient of the oil, B is the characteristic coefficient of the oil, and t is the temperature; The single-chip microcomputer (4) calculates the difference between two consecutive corrected differential pressure data as the differential pressure rise per unit time, and saves the data in an erasable programmable read-only memory. The formula for calculating the differential pressure rise within Δt0 time is: In the formula, △P 上升i Let ΔP be the increase in pressure difference during the time interval Δt0 during the i-th pressure difference measurement. 修正i This is the corrected differential pressure data from the i-th measurement; The single-chip microcomputer (4) calculates the average value of the pressure difference increase over time Δt0 based on the pressure difference increase value, and uses it as a parameter for the smooth pressure difference increase characteristic of the filter element: In the formula, △P 平缓 ΔP is a characteristic parameter when the filter element pressure differential rises gradually. 上升i This is the corrected differential pressure data from the i-th measurement, where i is the number of measurements. When calculating the pressure difference of the i-th measurement, compare ΔP 上升i With △P 平缓 The relationship when △P 上升i Greater than △P 平缓 When the pressure difference of the filter element is three times that of the filter element, it is considered to be in a rapid rising phase. The single-chip microcomputer (4) continuously records at least m times ΔP. 上升 , calculate △P 上升i , △P 上升i+1 , …… △P 上升i+m-1 When the increase in these pressure differences is greater than ΔP 平缓 When the pressure difference is three times that of the filter element, it is considered to be in a rapid rising phase. m is 5% of the total sample size to avoid flow fluctuations in the system containing the filter element. ΔP is considered to be within a short period of time. 上升i The sudden increase was misjudged as the filter element pressure differential reaching a rapid increase stage. After the filter element pressure difference reaches the rapid rise stage, the single-chip microcomputer (4) fits the filter element life curve, and the curve equation is: in Let i be the filter cartridge running time during the i-th measurement. ; The correction amount for the filter element pressure difference value during the i-th measurement; the coefficients a, b, c, d, e, and f are automatically obtained by the single-chip microcomputer (4) based on the curve; Based on the curve equation, the single-chip microcomputer (4) predicts the future V. i The pressure difference of the filter element at a given time point; when and hour, The corresponding time is the predicted lifespan of the filter element, where To replace the filter element with the required differential pressure as per design specifications, The future calculated by the single-chip microcomputer (4) based on the curve Predicted pressure difference over time.

2. The oil filter element life prediction device based on linear fitting according to claim 1, characterized in that: The single-chip microcomputer (4) is connected to a display screen (6). The single-chip microcomputer (4) records the corrected differential pressure data and time data on a two-dimensional coordinate system and displays the differential pressure change over time on the display screen (6).

3. The oil filter element life prediction device based on linear fitting according to claim 1, characterized in that: The single-chip microcomputer (4) is also equipped with a reset button. After the filter element is replaced, the data in the erasable programmable read-only memory (5) of the single-chip microcomputer (4) can be cleared by clicking the reset button, so that the device can be reset and the measurement data can be re-measured.

4. The oil filter element life prediction device based on linear fitting according to claim 1, characterized in that: The clock (3) is the internal clock of the single-chip microcomputer (4).

5. A method for predicting the lifespan of an oil filter element based on linear fitting, using the prediction device according to any one of claims 1-4, characterized in that: Includes the following steps: S1: The differential pressure, temperature and time of the filter element operation are measured by the differential pressure sensor (1), temperature sensor (2) and clock (3). The single-chip microcomputer (4) processes the data and stores it in the erasable programmable read-only memory (5). S2: The single-chip microcomputer (4) corrects the pressure difference data using temperature data; S3: Analyze whether the filter element has reached the stage of rapid increase in differential pressure based on the corrected differential pressure data. If it has not reached the stage, repeat S1 and S2. If it has reached the stage, proceed to the next step. S4: Fitting the filter cartridge life curve; S5: Predict the filter life based on the filter life curve.

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