A method for evaluating the life of a turbine oil

Abstract

The application relates to a steam turbine oil life evaluation method, which comprises the following steps: placing steam turbine oil to be evaluated in a steam turbine oil life evaluation device to carry out regular sampling detection, obtaining basic data; screening key indexes for evaluating the steam turbine oil life from the basic data based on an oxidation degradation theory; establishing an oxidation degradation rate equation of the key indexes according to the evolution law of the key indexes; combining the oxidation degradation rate equation of the key indexes with an Arrhenius oxidation kinetics equation to establish a steam turbine oil life evaluation model taking the key indexes as evaluation indexes; analyzing the evaluation results of the steam turbine oil life evaluation model taking the key indexes as evaluation indexes through a multilevel analysis method, and establishing a multi-evaluation steam turbine oil life prediction model based on the analysis results, so that the steam turbine oil life at any temperature can be evaluated and predicted. The steam turbine oil life evaluation method has high accuracy.

Description

Technical Field

[0001] This invention belongs to the field of turbine oil, and specifically relates to a method for evaluating the lifespan of turbine oil. Background Technology

[0002] Turbine oil is primarily used to lubricate the sliding bearings, reduction gears, and speed governors of steam turbine generator sets and hydro turbine generator sets. It also serves as the working medium for hydraulic systems. Because these units have large oil tanks and consume large quantities of oil, oil changes are costly. Therefore, establishing a reasonable oil change interval is crucial for ensuring the safe operation of the units and reducing costs.

[0003] Currently, oil quality and service life of turbine oils are typically assessed using empirical and standard monitoring of parameters such as acid value, moisture content, pour point, flash point, kinematic viscosity, rotating bomb oxidation, antioxidant content, varnish tendency index, and contamination level. However, some conventional parameters show relatively small changes, while oxidation indicators are the key factors in turbine oil degradation. Therefore, employing mechanistic analysis methods to screen out the key physicochemical indicators affecting turbine oil degradation can not only save on testing costs but also improve the targeting and efficiency of testing. This method avoids unnecessary testing of physicochemical indicators with minor impacts, thereby significantly improving the accuracy and reliability of the assessment.

[0004] Meanwhile, existing methods for assessing turbine oil life primarily rely on oven aging tests to evaluate changes in the physicochemical properties of the oil after aging. However, this method neglects the oxidative degradation of the oil during actual equipment use, lacking mechanistic explanations and the establishment of oxidative degradation models. Therefore, this method may not be able to accurately assess the life of turbine oil.

[0005] Therefore, the present invention provides a method for assessing the life of turbine oil to overcome the shortcomings of traditional assessment methods and to provide a more accurate theoretical basis for assessing the life of turbine oil. Summary of the Invention

[0006] This invention provides a method for evaluating the lifespan of turbine oil, comprising the following steps:

[0007] S1, the turbine oil to be evaluated is placed in the turbine oil life evaluation device for periodic sampling and testing to obtain basic data;

[0008] S2, based on the theory of oxidative degradation, key indicators for evaluating the life of turbine oil are screened from the basic data, and the key indicators include kinematic viscosity, acid value, oxidation value, antioxidant content, varnish tendency index and rotating oxygen bomb.

[0009] S3. Based on the evolution of the kinematic viscosity, acid value, oxidation value, antioxidant content, paint film tendency index, and rotating bomb, respectively establish the oxidative degradation rate equations for the kinematic viscosity, acid value, oxidation value, antioxidant content, paint film tendency index, and rotating bomb.

[0010] S4, combine the kinematic viscosity, acid value, oxidation value, antioxidant content, varnish tendency index and the oxidative degradation rate equation of the rotating bomb oxidation with the Arrhenius oxidation kinetic equation to establish turbine oil life assessment models with the kinematic viscosity, acid value, oxidation value, antioxidant content, varnish tendency index and rotating bomb oxidation as evaluation indicators.

[0011] S5. The evaluation results of the turbine oil life assessment model, which uses kinematic viscosity, acid value, oxidation value, antioxidant content, varnish tendency index and rotating oxygen bomb as evaluation criteria, are analyzed by multi-level analysis method. Based on the analysis results, a multi-evaluation turbine oil life prediction model is established to achieve the evaluation and prediction of turbine oil life at any temperature.

[0012] Preferably, the equation for the oxidative degradation rate of the kinematic viscosity is as follows: The equation for the oxidative degradation rate of kinematic viscosity, after logarithmic transformation, is as follows: Among them, L y0 The kinematic viscosity is the new oil value at room temperature, and Ly is the kinematic viscosity value at a certain test time; k y The oxidative degradation rate of the kinematic viscosity; t y The turbine oil life estimated based on the kinematic viscosity;

[0013] The equation for the oxidative degradation rate of the acid value is as follows: The equation for the oxidative degradation rate of the acid value, after logarithmic transformation, is as follows: Among them, L s0 The new oil value, L, represents the acid value at room temperature. s The acid value is the value at a certain test time; k s The acid value represents the oxidative degradation rate; t s The turbine oil life is estimated based on the acid value.

[0014] The equation for the oxidative degradation rate of the oxidation value is as follows: The equation for the oxidative degradation rate of the oxidation value, after logarithmic transformation, is as follows: Among them, L o0 The new oil value, L, represents the oxidation value at room temperature.o The oxidation value is the value at a certain test time; k o The oxidative degradation rate is the oxidation value; t o The turbine oil life is estimated based on the oxidation value.

[0015] The equation for the oxidative degradation rate of the antioxidant content is as follows: The equation for the oxidative degradation rate of the antioxidant content, after logarithmic transformation, is as follows: Among them, L k0 The new oil value for the antioxidant content at room temperature, L k The antioxidant content is the value at a certain test time; k k The oxidative degradation rate of the antioxidant content; t k The turbine oil life is estimated based on the antioxidant content mentioned above;

[0016] The formula for the oxidative degradation rate equation of the paint film tendency index is: The equation for the oxidative degradation rate of the paint film tendency index, after logarithmic transformation, is as follows: Among them, L q0 L represents the new oil value of the paint film tendency index at room temperature. q The value of the paint film tendency index at a certain test time; k q The oxidative degradation rate of the paint film tendency index; t q The turbine oil life is estimated using the aforementioned paint film tendency index;

[0017] The equation for the oxidative degradation rate of the rotating oxygen bomb is as follows: The equation for the oxidative degradation rate of the rotating oxygen bomb, after logarithmic transformation, is as follows: Among them, L x0 The new oil value of the rotating oxygen bomb at room temperature, L x k is the numerical value of the rotating oxygen bomb at a certain test time. x t represents the oxidative degradation rate of the rotating oxygen bomb. x The turbine oil life is estimated using the rotating oxygen bomb.

[0018] Preferably, the turbine oil life assessment model using kinematic viscosity as an evaluation index is as follows: The turbine oil life assessment model using acid value as an evaluation index is as follows: The turbine oil life assessment model using oxidation value as an evaluation index is as follows: The turbine oil life assessment model using antioxidant content as an evaluation index is as follows: The turbine oil life assessment model using the varnish tendency index as an evaluation index is as follows: The turbine oil life assessment model using the rotating oxygen bomb as an evaluation index is as follows: Among them, A y A s A o A k A q A x E is the frequency factor. y E s E o E k E q E x R is the activation energy of the reaction. y R s R o R k R q R x The gas constant is 8.314. T represents absolute temperature; L represents temperature. yfailure The failure value of the kinematic viscosity, L sfailure The failure value of the acid value, L ofailure The failure value of the oxidation value, L kfailure The failure value of the antioxidant content, L qfailure The failure value of the paint film tendency index, L xfailure L represents the failure value of the rotating oxygen bomb. y 0 represents the oil value of the kinematic viscosity, L s 0 represents the oil value of the acid value, L o 0 represents the oil value of the oxidation state, L k 0 represents the oil value of the antioxidant content, L q 0 represents the oil value of the paint film tendency index, L x 0 represents the oil value of the rotating oxygen bomb.

[0019] Preferably, the multi-evaluation turbine oil life prediction model is: , wherein, the P y The weight of the kinematic viscosity; the P s The weight of the acid value; the P o The weight of the oxidation value; the P q P represents the weight of the paint film tendency index; k The weight of the antioxidant content; P x The weight of the rotating oxygen bomb is given.

[0020] Preferably, the turbine oil life assessment device includes an oil filter, a check valve, a pressure gauge, a gear pump, a motor, a relief valve, a thermometer, a cooler, a temperature-adjustable constant-temperature oil tank, and hydraulic oil pipes connecting the above components; the oil filter is connected to the check valve via the hydraulic oil pipes, the check valve is connected to both the pressure gauge and the gear pump via the hydraulic oil pipes, the gear pump is connected to the temperature-adjustable constant-temperature oil tank via the hydraulic oil pipes, the temperature-adjustable constant-temperature oil tank is connected to the cooler via the hydraulic oil pipes, the cooler is connected to both the thermometer and the relief valve via the hydraulic oil pipes, and the motor is electrically connected to the gear pump.

[0021] Preferably, in step S1, the turbine oil to be evaluated is sampled and tested periodically, specifically as follows: the temperature-adjustable constant-temperature oil tank is set to 80°C, the frequency of periodic sampling and testing is 3 days / time, and the periodic sampling and testing cycle is 30 days; the temperature-adjustable constant-temperature oil tank is set to 100°C, the frequency of periodic sampling and testing is 2 days / time, and the periodic sampling and testing cycle is 20 days; the temperature-adjustable constant-temperature oil tank is set to 120°C, the frequency of periodic sampling and testing is 1 day / time, and the periodic sampling and testing cycle is 10 days.

[0022] Preferably, the kinematic viscosity is detected by the kinematic viscosity determination method and the dynamic viscosity calculation method for petroleum products; the acid value is detected by the acid value determination method for petroleum products; the oxidation value and the antioxidant content are detected by infrared spectroscopy; and the rotating oxygen bomb is detected by the oxidation stability of lubricating oil.

[0023] Compared with related technologies, the present invention has the following beneficial effects:

[0024] 1. The turbine oil life assessment device can simulate the oxidation and degradation process of turbine oil in the circulating oil circuit, avoiding the problem that traditional beaker thermal aging tests only consider thermal oxidation and thus ignore the problem that turbine oil may accelerate oxidation and degradation in the circulating oil circuit.

[0025] 2. Temperature is regulated by an adjustable temperature constant temperature oil tank, which accelerates the oxidation of turbine oil, shortens the oil oxidation cycle, and enables rapid assessment of turbine oil life.

[0026] 3. By combining the kinematic viscosity, acid value, oxidation value, antioxidant content, varnish tendency index, and the oxidation degradation rate equation of the rotating bomb oxidation with the Arrhenius oxidation kinetic equation, the life assessment of turbine oil at any temperature can be achieved, avoiding the problem of assessing the life of turbine oil at a certain operating temperature solely through device testing.

[0027] 4. This invention utilizes the theory of oxidative degradation to effectively screen key indicators for evaluating turbine oil life, thereby saving testing costs and avoiding the testing of less influential physicochemical indicators. Furthermore, by comprehensively evaluating multiple indicators, it avoids evaluation biases that may result from relying on a single indicator, thus improving the accuracy of the evaluation. Attached Figure Description

[0028] Figure 1 This is a flowchart illustrating a method for evaluating the lifespan of turbine oil according to the present invention.

[0029] Figure 2 This is a schematic diagram of the turbine oil life assessment device of the present invention. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Please also refer to the appendix. Figure 1-2 This invention provides a method for evaluating the life of turbine oil, comprising the following steps:

[0032] S1, the turbine oil to be evaluated is placed in the turbine oil life evaluation device for periodic sampling and testing to obtain basic data.

[0033] Specifically, the turbine oil life assessment device includes an oil filter 1, a one-way valve 2, a pressure gauge 3, a gear pump 4, a motor 5, a relief valve 6, a thermometer 8, a cooler 9, a temperature-adjustable constant-temperature oil tank 10, and hydraulic oil pipes 7 connecting the above components. The oil filter 1 is connected to the one-way valve 2 via the hydraulic oil pipe 7. The one-way valve 2 is connected to the pressure gauge 3 and the gear pump 4 via the hydraulic oil pipe 7. The gear pump 4 is connected to the temperature-adjustable constant-temperature oil tank 10 via the hydraulic oil pipe 7. The temperature-adjustable constant-temperature oil tank 10 is connected to the cooler 9 via the hydraulic oil pipe 7. The cooler 9 is connected to the thermometer 8 and the relief valve 6 via the hydraulic oil pipe 7. The motor 5 is electrically connected to the gear pump 4.

[0034] Furthermore, in S1, according to van der Hoff's law, the reaction rate increases with increasing temperature; for every 10-20K increase in reaction temperature, the reaction rate increases exponentially. Based on this, this embodiment selects a specific brand of turbine oil as the turbine oil to be evaluated and formulates three test schemes for the turbine oil to be evaluated at different temperatures, including temperature, time period, and sampling frequency, as shown in Table 1. Then, the turbine oil to be evaluated is placed in the adjustable temperature constant temperature oil tank 10 and set to constant temperatures of 80℃, 100℃, and 120℃ respectively to run the turbine oil life evaluation device. Through these tests of the turbine oil life evaluation device at different temperatures, the oxidative degradation behavior and lifespan of the turbine oil can be evaluated more accurately.

[0035]

[0036] By activating the turbine oil life assessment device, the oxidation and degradation process of turbine oil in the circulating oil circuit at different temperatures can be simulated. The temperature-adjustable constant temperature oil tank 10 can adjust the temperature change, thereby accelerating the oxidation of the oil, shortening the oil oxidation cycle, and realizing rapid assessment of turbine oil life.

[0037] According to the test plan, the turbine oil life assessment device was tested. Every preset time, the turbine oil to be assessed was extracted from the temperature-adjustable constant temperature oil tank 10, and the key indicators of the turbine oil to be assessed were detected to monitor the oxidation and degradation behavior of the oil and provide basic data for turbine oil life assessment.

[0038] Additionally, it should be noted that the complete procedure for the turbine oil life assessment device to test the turbine oil to be assessed is as follows:

[0039] (1) An assessment device for checking the life of the turbine oil:

[0040] Before starting the turbine oil life assessment device, it is necessary to correctly connect all pipelines and wiring according to the schematic diagram, and check whether the hydraulic oil pipes are correctly matched and connected to the actuator.

[0041] (2) Add the turbine oil to be evaluated:

[0042] Add an appropriate amount of the turbine oil to be evaluated. The turbine oil to be evaluated must be kept clean. Use a filler with a fine filter to inject the oil. Add the oil from the filter 1. Pay attention to the liquid level and add the required amount of oil. At the same time, check whether the temperature-adjustable constant temperature oil tank 10 and the pipeline are leaking.

[0043] (3) Adjust the temperature of the adjustable temperature constant temperature oil tank 10:

[0044] After adding an appropriate amount of the turbine oil to be evaluated, adjust the temperature-adjustable constant temperature oil tank 10 to the corresponding temperature. Once the temperature reaches the preset requirement, start the cooler 9.

[0045] (4) Activate the turbine oil life assessment device:

[0046] After the turbine oil temperature to be evaluated reaches the preset requirement, the turbine oil life evaluation device is started. Before starting the turbine oil life evaluation device, it is necessary to check again whether the pipeline is properly connected; jog the gear pump 4 and motor 5 to observe whether the rotation direction of motor 5 is correct. If it is incorrect, adjust the motor 5 wiring to ensure that motor 5 rotates in the correct direction; jog the motor 3 to 5 times to allow the gear pump 4 to fully draw in oil, and then start motor 5 normally to allow the turbine oil life evaluation device to operate normally.

[0047] (5) Regular sampling and testing:

[0048] During normal operation of the turbine oil life assessment device, the turbine oil to be assessed in the adjustable temperature constant temperature oil tank 10 is periodically sampled and tested according to the preset sampling frequency to establish basic data.

[0049] S2, based on the theory of oxidative degradation, selects key indicators from the basic data to evaluate the life of turbine oil, and the key indicators include kinematic viscosity, acid value, oxidation value, antioxidant content, varnish tendency index and rotating bomb of oxygen.

[0050] In this embodiment, based on the theory of oxidative degradation, the turbine oil to be evaluated undergoes a series of chain reactions during degradation, forming vapor-phase evaporated oil and low-molecular-weight products. Subsequently, the low-molecular-weight oxidation products evaporate to form vapor-phase products, such as ketones, aldehydes, alcohols, and acids. The remaining oxidative free radical byproducts polymerize into high-molecular-weight oxidation products, ultimately forming oxidative degradation products such as sludge and varnish. Based on this, kinematic viscosity, acid value, oxidation value, antioxidant content, varnish tendency index, and rotating bomb oxidation are selected as key indicators for turbine oil life assessment.

[0051] It is worth mentioning that the kinematic viscosity was tested using GB / T 265 Petroleum Products Kinematic Viscosity Determination and Dynamic Viscosity Calculation Method; the acid value was tested using GB / T 264 Petroleum Products Acid Value Determination Method; the oxidation value and the antioxidant content were tested using infrared spectroscopy; the rotating oxygen bomb was tested using SH / T 0193-2008 Lubricating Oil Oxidation Stability; and the varnish tendency index was tested using ASTM D 7843-2012 Standard Test Method for Mesurement of Lubricant Generated Insoluble Color Bodies in In-Service Turbine Oils using Membrane Patch Colorimetry.

[0052] S3. Based on the evolution of the kinematic viscosity, acid value, oxidation value, antioxidant content, paint film tendency index, and rotating bomb oxidation, respectively establish the oxidative degradation rate equations for the kinematic viscosity, acid value, oxidation value, antioxidant content, paint film tendency index, and rotating bomb oxidation.

[0053] In this embodiment, based on the evolution of kinematic viscosity, acid value, oxidation value, antioxidant content, paint film tendency index, and rotating bomb oxidation over time, oxidative degradation rate equations for the kinematic viscosity, acid value, oxidation value, antioxidant content, paint film tendency index, and rotating bomb oxidation are established using first-order integral rate equations. The oxidation rate at a specific temperature is obtained by solving these equations. The specific formulas are as follows:

[0054] The equation for the oxidative degradation rate of the kinematic viscosity is as follows: The equation for the oxidative degradation rate of kinematic viscosity, after logarithmic transformation, is as follows: Among them, L y0 The kinematic viscosity is the new oil value at room temperature, and Ly is the kinematic viscosity value at a certain test time; k y The oxidative degradation rate of the kinematic viscosity; t y The turbine oil life estimated based on the kinematic viscosity;

[0055] The equation for the oxidative degradation rate of the acid value is as follows: The equation for the oxidative degradation rate of the acid value, after logarithmic transformation, is as follows: Among them, L s0The new oil value, L, represents the acid value at room temperature. s The acid value is the value at a certain test time; k s The acid value represents the oxidative degradation rate; t s The turbine oil life is estimated based on the acid value.

[0056] The equation for the oxidative degradation rate of the oxidation value is as follows: The equation for the oxidative degradation rate of the oxidation value, after logarithmic transformation, is as follows: Among them, L o0 The new oil value, L, represents the oxidation value at room temperature. o The oxidation value is the value at a certain test time; k o The oxidative degradation rate is the oxidation value; t o The turbine oil life is estimated based on the oxidation value.

[0057] The equation for the oxidative degradation rate of the antioxidant content is as follows: The equation for the oxidative degradation rate of the antioxidant content, after logarithmic transformation, is as follows: Among them, L k0 The new oil value for the antioxidant content at room temperature, L k The antioxidant content is the value at a certain test time; k k The oxidative degradation rate of the antioxidant content; t k The turbine oil life is estimated based on the antioxidant content mentioned above;

[0058] The formula for the oxidative degradation rate equation of the paint film tendency index is: The equation for the oxidative degradation rate of the paint film tendency index, after logarithmic transformation, is as follows: Among them, L q0 L represents the new oil value of the paint film tendency index at room temperature. q The value of the paint film tendency index at a certain test time; k q The oxidative degradation rate of the paint film tendency index; t q The turbine oil life is estimated using the aforementioned paint film tendency index;

[0059] The equation for the oxidative degradation rate of the rotating oxygen bomb is as follows: The equation for the oxidative degradation rate of the rotating oxygen bomb, after logarithmic transformation, is as follows:

[0060] Among them, L x0 The new oil value of the rotating oxygen bomb at room temperature, L x k is the numerical value of the rotating oxygen bomb at a certain test time. xt represents the oxidative degradation rate of the rotating oxygen bomb. x The turbine oil life is estimated using the rotating oxygen bomb.

[0061] S4, combine the kinematic viscosity, acid value, oxidation value, antioxidant content, varnish tendency index and the oxidative degradation rate equation of the rotating bomb oxidation with the Arrhenius oxidation kinetic equation to establish turbine oil life assessment models with the kinematic viscosity, acid value, oxidation value, antioxidant content, varnish tendency index and rotating bomb oxidation as evaluation indicators.

[0062] In this embodiment, the Arhenius oxidation kinetic equation is: Where A is the frequency factor; E is the activation energy of the reaction; and R is the gas constant, R = 8.314. T is the absolute temperature, and K is the oxidation rate.

[0063] The kinematic viscosity, acid value, oxidation value, antioxidant content, varnish tendency index, and oxidative degradation rate equation of the rotating bomb oxidation system are combined with the Arrhenius oxidation kinetic equation to obtain the following turbine oil life assessment model:

[0064] The turbine oil life assessment model using kinematic viscosity as the evaluation index is as follows: The turbine oil life assessment model using acid value as an evaluation index is as follows: The turbine oil life assessment model using oxidation value as an evaluation index is as follows: The turbine oil life assessment model using antioxidant content as an evaluation index is as follows: The turbine oil life assessment model using the varnish tendency index as an evaluation indicator is as follows: The turbine oil life assessment model using the rotating oxygen bomb as an evaluation index is as follows: Among them, A y A s A o A k A q A x E is the frequency factor. y E s E o E k E q E x R is the activation energy of the reaction. y R s R o R k R q R xThe gas constant is 8.314. T represents absolute temperature; L represents temperature. yfailure The failure value of the kinematic viscosity, L sfailure The failure value of the acid value, L ofailure The failure value of the oxidation value, L kfailure The failure value of the antioxidant content, L qfailure The failure value of the paint film tendency index, L xfailure L represents the failure value of the rotating oxygen bomb. y 0 represents the oil value of the kinematic viscosity, L s 0 represents the oil value of the acid value, L o 0 represents the oil value of the oxidation state, L k 0 represents the oil value of the antioxidant content, L q 0 represents the oil value of the paint film tendency index, L x 0 represents the oil value of the rotating oxygen bomb.

[0065] In the above model, according to the standard NB / SH / T0636L-TSA turbine oil change index, the failure value of kinematic viscosity exceeds ±10% of that of new oil; the failure value of acid value is a change greater than 0.3 mgKOH / g; and the failure value of rotating bomb oxidation is less than 25% of that of new oil. However, the failure thresholds for oxidation value, antioxidant content, and varnish tendency index need to be determined during the testing process.

[0066] S5. The evaluation results of the turbine oil life assessment model, which uses kinematic viscosity, acid value, oxidation value, antioxidant content, varnish tendency index and rotating oxygen bomb as evaluation criteria, are analyzed by multi-level analysis method. Based on the analysis results, a multi-evaluation turbine oil life prediction model is established to achieve the evaluation and prediction of turbine oil life at any temperature.

[0067] In this embodiment, the multi-evaluation turbine oil life prediction model is: , wherein, the P y The weight of the kinematic viscosity; the P s The weight of the acid value; the P o The weight of the oxidation value; the P q P represents the weight of the paint film tendency index; k The weight of the antioxidant content; P x The weight of the rotating oxygen bomb is given.

[0068] Furthermore, the importance of kinematic viscosity, acid value, oxidation value, antioxidant content, varnish tendency index, and rotating bomb oxidation as evaluation results of the turbine oil life assessment model is determined using the analytic hierarchy process (AHP), and the corresponding weights are calculated. Then, these weights are allocated to the corresponding single-evaluation index life assessment models to establish a highly reliable multi-evaluation turbine oil life prediction model. The steps for determining the weights using the AHP are as follows:

[0069] First, the hierarchical structure is determined, divided into two layers: the target layer and the factor layer. The target layer is defined as "the importance of the evaluation results of the turbine oil life assessment model for the kinematic viscosity, acid value, oxidation value, antioxidant content, varnish tendency index, and rotating oxygen bomb," while the factor layer comprises "kinematic viscosity," "acid value," "oxidation value," "varnish tendency index," "antioxidant content," and "rotating oxygen bomb."

[0070] Then, a judgment matrix is ​​established to measure the relative importance between the two indicators. The matrix is ​​then subjected to a consistency test, and the weights of different evaluation indicators are obtained: Py for kinematic viscosity, Ps for acid value, Po for oxidation value, Pq for varnish tendency index, Pk for antioxidant content, and Px for rotating bomb oxidation. Based on the weights of these different evaluation indicators, a multi-evaluation turbine oil life prediction model is established.

[0071] Compared with related technologies, the present invention has the following beneficial effects:

[0072] 1. The turbine oil life assessment device can simulate the oxidation and degradation process of turbine oil in the circulating oil circuit, avoiding the problem that traditional beaker thermal aging tests only consider thermal oxidation and thus ignore the problem that turbine oil may accelerate oxidation and degradation in the circulating oil circuit.

[0073] 2. Temperature is regulated by an adjustable temperature constant temperature oil tank, which accelerates the oxidation of turbine oil, shortens the oil oxidation cycle, and enables rapid assessment of turbine oil life.

[0074] 3. By combining the kinematic viscosity, acid value, oxidation value, antioxidant content, varnish tendency index, and the oxidation degradation rate equation of the rotating bomb oxidation with the Arrhenius oxidation kinetic equation, the life assessment of turbine oil at any temperature can be achieved, avoiding the problem of assessing the life of turbine oil at a certain operating temperature solely through device testing.

[0075] 4. This invention utilizes the theory of oxidative degradation to effectively screen key indicators for evaluating turbine oil life, thereby saving testing costs and avoiding the testing of less influential physicochemical indicators. Furthermore, by comprehensively evaluating multiple indicators, it avoids evaluation biases that may result from relying on a single indicator, thus improving the accuracy of the evaluation.

[0076] It should be noted that the above-described embodiments should be understood as illustrative, not as limiting the scope of protection of this invention. The scope of protection of this invention is defined by the claims. For those skilled in the art, some non-essential improvements and adjustments made to this invention without departing from the essence and scope of this invention still fall within the scope of protection of this invention.

Claims

1. A method for evaluating the lifespan of turbine oil, characterized in that, The method includes the following steps: S1, the turbine oil to be evaluated is placed in the turbine oil life evaluation device for periodic sampling and testing to obtain basic data; S2, based on the theory of oxidative degradation, key indicators for evaluating the life of turbine oil are screened from the basic data, and the key indicators include kinematic viscosity, acid value, oxidation value, antioxidant content, varnish tendency index and rotating oxygen bomb. S3. Based on the evolution of the kinematic viscosity, acid value, oxidation value, antioxidant content, paint film tendency index, and rotating bomb, respectively establish the oxidative degradation rate equations for the kinematic viscosity, acid value, oxidation value, antioxidant content, paint film tendency index, and rotating bomb. S4, combine the kinematic viscosity, acid value, oxidation value, antioxidant content, varnish tendency index and the oxidative degradation rate equation of the rotating bomb oxidation with the Arrhenius oxidation kinetic equation to establish turbine oil life assessment models with the kinematic viscosity, acid value, oxidation value, antioxidant content, varnish tendency index and rotating bomb oxidation as evaluation indicators. S5. The evaluation results of the turbine oil life assessment model, which uses kinematic viscosity, acid value, oxidation value, antioxidant content, varnish tendency index and rotating bomb of oxygen as evaluation criteria, are analyzed by multi-level analysis method. Based on the analysis results, a multi-evaluation turbine oil life prediction model is established to achieve the evaluation and prediction of turbine oil life at any temperature. The equation for the oxidative degradation rate of the kinematic viscosity is as follows: The equation for the oxidative degradation rate of kinematic viscosity, after logarithmic transformation, is as follows: Among them, L y0 The kinematic viscosity is the new oil value at room temperature, and Ly is the kinematic viscosity value at a certain test time; k y The oxidative degradation rate of the kinematic viscosity; t y The turbine oil life estimated based on the kinematic viscosity; The equation for the oxidative degradation rate of the acid value is as follows: The equation for the oxidative degradation rate of the acid value, after logarithmic transformation, is as follows: Among them, L s0 The new oil value, L, represents the acid value at room temperature. s The acid value is the value at a certain test time; k s The oxidative degradation rate of the acid value; t s The turbine oil life is estimated based on the acid value. The equation for the oxidative degradation rate of the oxidation value is as follows: The equation for the oxidative degradation rate of the oxidation value, after logarithmic transformation, is as follows: Among them, L o0 The new oil value, L, represents the oxidation value at room temperature. o The oxidation value is the value at a certain test time; k o The oxidative degradation rate is the oxidation value; t o The turbine oil life is estimated based on the oxidation value. The equation for the oxidative degradation rate of the antioxidant content is as follows: The equation for the oxidative degradation rate of the antioxidant content, after logarithmic transformation, is as follows: Among them, L k0 The new oil value for the antioxidant content at room temperature, L k The antioxidant content is the value at a certain test time; k k The oxidative degradation rate of the antioxidant content; t k The turbine oil life is estimated based on the antioxidant content mentioned above; The formula for the oxidative degradation rate equation of the paint film tendency index is: The equation for the oxidative degradation rate of the paint film tendency index, after logarithmic transformation, is as follows: Among them, L q0 L represents the new oil value of the paint film tendency index at room temperature. q The value of the paint film tendency index at a certain test time; k q The oxidative degradation rate of the paint film tendency index; t q The turbine oil life is estimated using the aforementioned paint film tendency index; The equation for the oxidative degradation rate of the rotating oxygen bomb is as follows: The equation for the oxidative degradation rate of the rotating oxygen bomb, after logarithmic transformation, is as follows: Among them, L x0 The new oil value of the rotating oxygen bomb at room temperature, L x k is the numerical value of the rotating oxygen bomb at a certain test time. x t represents the oxidative degradation rate of the rotating oxygen bomb. x The turbine oil life is estimated using the rotating oxygen bomb.

2. The method for evaluating the life of turbine oil according to claim 1, characterized in that, The turbine oil life assessment model using kinematic viscosity as the evaluation index is as follows: The turbine oil life assessment model using acid value as an evaluation index is as follows: The turbine oil life assessment model using oxidation value as an evaluation index is as follows: The turbine oil life assessment model using antioxidant content as an evaluation index is as follows: The turbine oil life assessment model using the varnish tendency index as an evaluation index is as follows: The turbine oil life assessment model using the rotating oxygen bomb as an evaluation index is as follows: Among them, A y A s A o A k A q A x E is the frequency factor. y E s E o E k E q E x R is the activation energy of the reaction. y R s R o R k R q R x The gas constant is 8.

314. T represents absolute temperature; L represents temperature. yfailure The failure value of the kinematic viscosity, L sfailure The failure value of the acid value, L ofailure The failure value of the oxidation value, L kfailure The failure value of the antioxidant content, L qfailure The failure value of the paint film tendency index, L xfailure L represents the failure value of the rotating oxygen bomb. y 0 represents the oil value of the kinematic viscosity, L s 0 represents the oil value of the acid value, L o 0 represents the oil value of the oxidation state, L k 0 represents the oil value of the antioxidant content, L q 0 represents the oil value of the paint film tendency index, L x 0 represents the oil value of the rotating oxygen bomb.

3. The method for evaluating the lifespan of turbine oil according to claim 2, characterized in that, The multi-evaluation turbine oil life prediction model is as follows: , wherein, the P y The weight of the kinematic viscosity; the P s The weight of the acid value; the P o The weight of the oxidation value; the P q P represents the weight of the paint film tendency index; k The weight of the antioxidant content; P x The weight of the rotating oxygen bomb is given.

4. The method for evaluating the life of turbine oil according to claim 1, characterized in that, The turbine oil life assessment device includes an oil filter, a check valve, a pressure gauge, a gear pump, a motor, a relief valve, a thermometer, a cooler, a temperature-adjustable constant-temperature oil tank, and hydraulic oil pipes connecting the above components. The oil filter is connected to the check valve via the hydraulic oil pipes. The check valve is connected to both the pressure gauge and the gear pump via the hydraulic oil pipes. The gear pump is connected to the temperature-adjustable constant-temperature oil tank via the hydraulic oil pipes. The temperature-adjustable constant-temperature oil tank is connected to the cooler via the hydraulic oil pipes. The cooler is connected to both the thermometer and the relief valve via the hydraulic oil pipes. The motor is electrically connected to the gear pump.

5. The method for evaluating the life of turbine oil according to claim 4, characterized in that, In step S1, the turbine oil to be evaluated is sampled and tested periodically, specifically as follows: the temperature-adjustable constant-temperature oil tank is set to 80℃, the sampling frequency is 3 days / time, and the sampling cycle is 30 days; the temperature-adjustable constant-temperature oil tank is set to 100℃, the sampling frequency is 2 days / time, and the sampling cycle is 20 days; the temperature-adjustable constant-temperature oil tank is set to 120℃, the sampling frequency is 1 day / time, and the sampling cycle is 10 days.

6. The method for evaluating the life of turbine oil according to claim 1, characterized in that, The kinematic viscosity was determined by the kinematic viscosity test method and the dynamic viscosity calculation method for petroleum products; the acid value was determined by the acid value test method for petroleum products; the oxidation value and the antioxidant content were determined by infrared spectroscopy; and the rotating oxygen bomb was determined by the oxidation stability of lubricating oil.

Images