Method for rapid evaluation of degradation degree of in-service turbine oil based on infrared spectrum

Abstract

The present application relates to the technical field of lubricating oil evaluation of refining and chemical rotating equipment, and is a rapid evaluation method for the deterioration degree of in-service turbine oil based on infrared spectrum, which comprises the following steps: obtaining the change rate of deterioration products in the to-be-tested oil (△S) according to the infrared absorption data of the to-be-tested oil and new oil at a first absorption wave band; obtaining the change rate of antioxidant content in the to-be-tested oil (△H) according to the infrared absorption data of the to-be-tested oil and new oil at a second absorption wave band; and judging that the to-be-tested oil has obvious deterioration when △H≥N and △S≥M, wherein N and M are judgment thresholds respectively. The present application can rapidly evaluate the deterioration degree of in-service turbine oil of large rotating machinery, provide early warning and intervention, realize predictive maintenance of lubricating oil of large rotating machinery of refining and chemical devices, improve the operation reliability, and is simple in steps, strong in applicability, and convenient for popularization and application.

Description

Technical Field

[0001] This invention relates to the field of lubricating oil evaluation technology for refining and chemical rotating equipment, and is a rapid assessment method for the degree of deterioration of in-use turbine oil based on infrared spectroscopy. Background Technology

[0002] As the core power equipment of refining and chemical plants, the safe, stable, and smooth operation of large rotating machinery is directly related to the reliability of the plant's operation. Large rotating machinery in refining and chemical plants usually uses turbine oil. During operation, turbine oil is affected by factors such as heat, oxygen, moisture, and metal particles, which will cause oxidation and continuous deterioration. When the turbine oil in use deteriorates to a certain extent, it will affect the stable operation of the rotating machinery. Therefore, it is of great significance to quickly assess the degree of deterioration of the turbine oil in use in large rotating machinery.

[0003] Rapidly assessing the degree of deterioration of turbine oil in large rotating machinery not only enables equipment to change oil according to its quality, but is also a key technical means to achieve predictive lubrication maintenance of large rotating machinery.

[0004] In actual operation of production facilities, large rotating machinery regularly samples and analyzes five conventional parameters of turbine oil in use each month: kinematic viscosity at 40℃, acid value, moisture content, flash point, and mechanical impurities. The degradation of the turbine oil in use is comprehensively judged by combining the monitoring results of kinematic viscosity at 40℃, acid value, and flash point. The monitoring results over many years show that these conventional parameters change very little. Detecting only these parameters cannot accurately assess the degree of degradation of the turbine oil in use, and therefore cannot accurately determine the replacement time of the turbine oil in use.

[0005] US Patent Publication No. US10132744B2 discloses a method for managing lubricating oil and a method for predicting lubricating oil life. The method manages lubricating oil by determining the degree of degradation of lubricating oil containing antioxidants, specifically according to the following determination methods a and b. Determination method a includes: measuring the infrared absorption spectrum of the lubricating oil using a Fourier transform infrared spectrometer; and calculating the total content of the antioxidant and altering substances with antioxidant functions to determine the degree of deterioration of the lubricating oil from the obtained content. Determination method b includes: filtering the lubricating oil with a filter; subsequently measuring the color difference of the substances captured by the filter using a colorimeter, or measuring the color difference of the lubricating oil using a colorimeter, and determining the degree of degradation of the lubricating oil and the degree of mixing of foreign matter based on the obtained color difference.

[0006] US Patent Publication No. US5049742A discloses an apparatus for detecting the deterioration of engine oil. This apparatus includes a ceramic heater that emits infrared light at a wavelength of 6.1 micrometers, equal to the specific infrared absorption peak of nitrate esters in the engine oil. The infrared light is passed through a bandpass filter with a center wavelength of 6.1 micrometers and incident on a photodetector to detect the nitrate ester content in the engine oil. Experiments have shown that the amount of nitrate esters is directly proportional to the total acid value, which is an indicator of the degree of engine oil deterioration. Therefore, by appropriately processing the output signal of the photodetector, it is possible to detect the degree of engine oil deterioration. The detected deterioration can then be displayed on a display device provided on the front pedal of the vehicle.

[0007] US Patent Publication No. US20230046877A1 discloses an oil deterioration diagnostic device, specifically an oil deterioration diagnostic device that can accurately, in real time, and detect oil deterioration at an early stage during machine operation without the need for oil extraction. An oil deterioration diagnostic device 10 for engineering machinery including a hydraulic circuit 1 includes: a floodlight projector 11a configured to irradiate oil flowing through the hydraulic circuit 1 with measuring light having a predetermined wavenumber or wavelength during operation of the engineering machinery; a light receiver 11b configured to receive transmitted light penetrating the oil; a signal processing unit 11c configured to continuously or intermittently measure absorbance or transmittance; and a diagnostic unit 12 configured to detect a decrease in antioxidants or an increase in peroxides in the oil based on changes in absorbance or transmittance.

[0008] Japanese patent document with publication number JP1996226896A discloses a method for detecting the deterioration of lubricating oil, which measures the content of antioxidants in lubricating oil using an infrared spectroscopy analyzer to determine the degree of deterioration of lubricating oils such as engine oil.

[0009] Chinese patent document CN105954225A discloses a method for determining the replacement cycle of diesel engine lubricating oil. The method uses a mid-infrared spectrometer to detect the lubricating oil sample and obtain its mid-infrared spectrum. The absorbance value of the absorption peak in the wavenumber range of 1300–1400 v / m is selected from the mid-infrared spectrum. When the absorbance value is greater than or equal to 0.36, the lubricating oil does not need to be replaced; when the absorbance value is between 0.31 and 0.36, the lubricating oil can be replaced; and when the absorbance value is less than or equal to 0.31, the lubricating oil must be replaced. This method is simple, easy to implement, and has good reliability, enabling rapid and accurate determination of the diesel engine lubricating oil replacement cycle. This invention also discloses a determination device based on this method, which can be installed in the existing diesel engine lubrication system to achieve continuous measurement of the lubricating oil quality during diesel engine operation.

[0010] Chinese patent document CN102830083A discloses a rapid testing method for lubricating oil changes in heavy-duty diesel engines. The method is characterized by the following specific testing steps: The heavy-duty diesel engine is a FAW-developed National III heavy-duty diesel engine. After a certain mileage, when testing whether an oil change is needed, the engine is kept at idle speed, and approximately 100 mL of engine oil is taken from the dipstick tube. The oxidation value of the engine oil is detected using infrared spectroscopy and a fully automatic oxidation value analyzer. The oxidation value is an indicator of the engine lubricating oil's antioxidant performance. It is determined by the absorption of the carbonyl group stretching vibration at 1720 cm⁻¹ in the infrared spectrum, which can analyze the changes in oxides generated by high-temperature oxidation of the engine lubricating oil during vehicle use. The method uses oxidation value analysis to determine the engine lubricating oil replacement cycle, achieving both economical oil use and ensuring good engine operation.

[0011] Chinese patent document CN108318411A discloses a method for assessing the remaining service life of lubricating oil, including the following steps: 1) placing the lubricating oil to be assessed in a beaker, and then conducting an aging trend analysis test on the lubricating oil to be assessed. At the same time, during the aging trend analysis test, samples are extracted from the lubricating oil to be assessed at preset time intervals, and then the rotational bomb value, varnish tendency, acid value, steel rod corrosion performance, antioxidant content, and kinematic viscosity of the samples are detected; 2) assessing the remaining service life of the lubricating oil based on the rotational bomb value, varnish tendency, acid value, steel rod corrosion performance, antioxidant content, and kinematic viscosity of each sample. This method can accurately assess the remaining service life of lubricating oil.

[0012] Chinese patent document CN117476127A discloses a method and apparatus for predicting the physical properties of oil products using spectral information. The method includes: measuring the near-infrared spectrum of a sample to be tested and performing second-order differential processing; selecting absorbance in a characteristic spectral region to form a spectral vector x; for the physical property to be tested, solving X = T × P using the PLS algorithm to obtain a score vector p of the spectral vector x; fitting the score vector p using a score matrix in an oil near-infrared score database, obtaining non-zero fitting coefficients using the non-negative constrained least squares method, and normalizing them to obtain normalized fitting coefficients; using these normalized fitting coefficients to calculate the fitting score vector of the sample to be tested; using the fitting score vector to calculate the goodness of fit of the database to the sample to be tested; and, if the goodness of fit is greater than a threshold, predicting the physical property to be tested of the sample to be tested based on the physical properties corresponding to the database samples involved in the fitting. This method can quickly and accurately predict the physical properties of the oil product to be tested.

[0013] The existing technologies mentioned above still have the following shortcomings and defects in the evaluation of the deterioration of in-use turbine oil: they require a lot of instruments and equipment, have long analysis cycles, lack accuracy, and have significant limitations in evaluation methods. This leads to a certain deviation between the evaluation results of the degree of deterioration of in-use turbine oil and the actual situation, and cannot meet the actual needs of predictive maintenance of lubrication for large rotating machinery in refining and chemical plants. Summary of the Invention

[0014] This invention provides a rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy, which overcomes the shortcomings of the prior art and can effectively solve the problems of long analysis cycle and insufficient accuracy of existing methods for evaluating or detecting the degree of degradation of in-use turbine oil.

[0015] The technical solution of this invention is achieved through the following measures: a rapid assessment method for the degree of deterioration of in-use turbine oil based on infrared spectroscopy, comprising the following steps: S1, based on the infrared absorption data of the test oil and new oil at the first absorption band, the change rate ΔS of deterioration products in the test oil is obtained; S2, based on the infrared absorption data of the test oil and new oil in the second absorption band, the change rate ΔH of antioxidant content in the test oil is obtained; S3, when △H≥N and △S≥M, it is determined that the test oil has deteriorated significantly, where N and M are the judgment thresholds; The oil to be tested is a turbine oil used in large rotating machinery, and the new oil is a new oil in a barrel of the same type as the turbine oil used in large rotating machinery.

[0016] The following are further optimizations and / or improvements to the above-mentioned technical solution: The above-mentioned rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy, before step S1, further includes: S0, perform infrared spectral analysis on the test oil and new oil to obtain infrared absorption data of the test oil and the new oil.

[0017] The aforementioned rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy also includes: S4. For engine oils that show significant deterioration, partially replace the oil with new oil online. S5, perform infrared spectral scanning on the replaced engine oil to obtain infrared absorption data of the replaced engine oil in the first absorption band and the second absorption band. S6. Based on the infrared absorption data of the replaced test oil and the new oil at the first absorption band and the second absorption band, the change rate of deterioration products △S' and the change rate of antioxidant content △H' in the replaced test oil are obtained. S7. If △H' < N and △S' < M, then resume use; otherwise, repeat steps S4 to S6 until △H' < N and △S' < M.

[0018] The first absorption band mentioned above has a wavelength of 1760 cm. -1 Up to 1660cm -1 .

[0019] The second absorption band mentioned above has a wavelength of 3650 cm. -1 Up to 3651cm -1 .

[0020] In step S4 above, 25% to 40% of the oil is replaced online with new oil.

[0021] Step S2 above includes: Based on the infrared absorption data of the test oil and new oil in the first absorption band, the infrared absorption peak area of ​​the test oil and new oil in the first absorption band is calculated to obtain the change rate ΔS of deterioration products in the test oil. The rate of change of degradation products ΔS in the tested engine oil is calculated using the following formula: △S = (S1 - S0) / S0 × 100% In the formula, S0 is the infrared absorption peak area in the first absorption band of the new oil, and S1 is the infrared absorption peak area in the first absorption band of the oil to be tested.

[0022] Step S3 above includes: Based on the infrared absorption data of the test oil and new oil in the second absorption band, the height of the highest absorption peak of the test oil and new oil in the second absorption band is obtained, and the change rate of antioxidant content ΔH in the test oil is calculated. The rate of change ΔH of antioxidant content in the tested engine oil is calculated using the following formula: △H = (H0 - H1) / H0 × 100% In the formula, H0 is the highest absorption peak height of the new oil in the second absorption band, and H1 is the highest absorption peak height of the oil under test in the second absorption band.

[0023] Step S6 above includes: The change rate ΔS' of deterioration products in the replaced test oil is obtained based on the infrared absorption peak area of ​​the replaced test oil and the new oil in the first absorption band. The change rate ΔS' of degradation products of the replaced test oil in the working turbine oil is calculated using the following formula: △S' = (S2 - S0) / S0 × 100% In the formula, S0 is the infrared absorption peak area in the first absorption band of the new oil, and S2 is the infrared absorption peak area in the first absorption band of the replaced oil to be tested. The change rate of antioxidant content in the replaced test oil ΔH' is obtained based on the highest absorption peak height of the replaced test oil and the new oil in the second absorption band. The rate of change of antioxidant content ΔH' in the tested engine oil after replacement is calculated using the following formula: △H' = (H0 - H2) / H0 × 100% In the formula, H0 is the highest absorption peak height of the new oil in the second absorption band, and H2 is the highest absorption peak height of the replaced oil in the second absorption band.

[0024] The above N is 75% and M is 50%.

[0025] This invention provides a rapid assessment method for the degradation degree of in-use turbine oil based on infrared spectroscopy. It enables rapid evaluation of the degradation degree of in-use turbine oil in large rotating machinery, allowing for early warning and intervention. This method enables predictive maintenance of lubricating oil in large rotating machinery in refining and chemical plants, improving their operational reliability. The method is simple, highly applicable, and easy to promote and apply. Attached Figure Description

[0026] Appendix Figure 1 The infrared spectrum of a brand of new L-TSA32 turbine oil in a drum from generator set #2 of the power plant's power generation operation department in Embodiment 12 of the present invention.

[0027] Appendix Figure 2 The infrared spectrum of a certain brand of turbine oil L-TSA32 used in the No. 2 generator set of the power generation operation department of the thermal power plant in Embodiment 12 of the present invention.

[0028] Appendix Figure 3The image shows the infrared spectrum of a brand of new L-TSA46 turbine oil in a drum from the No. 1 generator unit of the combined operation department of the thermal power plant in Embodiment 13 of the present invention.

[0029] Appendix Figure 4 The infrared spectrum of a certain brand of turbine oil L-TSA46 in use for generator set No. 1 of the combined operation department of the thermal power plant in Embodiment 13 of the present invention. Detailed Implementation

[0030] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.

[0031] The present invention will be further described below with reference to embodiments: Example 1: The rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy includes the following steps: S1, based on the infrared absorption data of the test oil and new oil at the first absorption band, the change rate ΔS of deterioration products in the test oil is obtained; S2, based on the infrared absorption data of the test oil and new oil in the second absorption band, the change rate ΔH of antioxidant content in the test oil is obtained; S3, when △H≥N and △S≥M, it is determined that the test oil has deteriorated significantly, where N and M are the judgment thresholds; The oil to be tested is a turbine oil used in large rotating machinery, and the new oil is a new oil in a barrel of the same type as the turbine oil used in large rotating machinery.

[0032] Example 2: As an optimization of the above embodiment, the rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy further includes the following step before step S1: S0, perform infrared spectral analysis on the test oil and new oil to obtain infrared absorption data of the test oil and the new oil.

[0033] Example 3: As an optimization of the above embodiments, the rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy further includes: S4. For engine oils that show significant deterioration, partially replace the oil with new oil online. S5, perform infrared spectral scanning on the replaced engine oil to obtain infrared absorption data of the replaced engine oil in the first absorption band and the second absorption band. S6. Based on the infrared absorption data of the replaced test oil and the new oil at the first absorption band and the second absorption band, the change rate of deterioration products △S' and the change rate of antioxidant content △H' in the replaced test oil are obtained. S7. If △H' < N and △S' < M, then resume use; otherwise, repeat steps S4 to S6 until △H' < N and △S' < M.

[0034] Example 4: As an optimization of the above embodiment, the first absorption band has a wavelength of 1760cm. -1 Up to 1660cm -1 .

[0035] Example 5: As an optimization of the above embodiment, the second absorption band has a wavelength of 3650 cm. -1 Up to 3651cm -1 .

[0036] Example 6: As an optimization of the above example, in step S4, 25% to 40% of the oil is replaced online with new oil.

[0037] Example 7: As an optimization of the above embodiment, step S2 includes: Based on the infrared absorption data of the test oil and new oil in the first absorption band, the infrared absorption peak area of ​​the test oil and new oil in the first absorption band is calculated to obtain the change rate ΔS of deterioration products in the test oil. The rate of change of degradation products ΔS in the tested engine oil is calculated using the following formula: △S = (S1 - S0) / S0 × 100% In the formula, S0 is the infrared absorption peak area in the first absorption band of the new oil, and S1 is the infrared absorption peak area in the first absorption band of the oil to be tested.

[0038] Example 8: As an optimization of the above embodiment, step S3 includes: Based on the infrared absorption data of the test oil and new oil in the second absorption band, the height of the highest absorption peak of the test oil and new oil in the second absorption band is obtained, and the change rate of antioxidant content ΔH in the test oil is calculated. The rate of change ΔH of antioxidant content in the tested engine oil is calculated using the following formula: △H = (H0 - H1) / H0 × 100% In the formula, H0 is the highest absorption peak height of the new oil in the second absorption band, and H1 is the highest absorption peak height of the oil under test in the second absorption band.

[0039] Example 9: As an optimization of the above embodiment, step S6 includes: The change rate ΔS' of deterioration products in the replaced test oil is obtained based on the infrared absorption peak area of ​​the replaced test oil and the new oil in the first absorption band. The change rate ΔS' of degradation products of the replaced test oil in the working turbine oil is calculated using the following formula: △S' = (S2 - S0) / S0 × 100% In the formula, S0 is the infrared absorption peak area in the first absorption band of the new oil, and S2 is the infrared absorption peak area in the first absorption band of the replaced oil to be tested. The change rate of antioxidant content in the replaced test oil ΔH' is obtained based on the highest absorption peak height of the replaced test oil and the new oil in the second absorption band. The rate of change of antioxidant content ΔH' in the tested engine oil after replacement is calculated using the following formula: △H' = (H0 - H2) / H0 × 100% In the formula, H0 is the highest absorption peak height of the new oil in the second absorption band, and H2 is the highest absorption peak height of the replaced oil in the second absorption band.

[0040] Example 10: As an optimization of the above example, N is 75% and M is 50%.

[0041] The purpose of this invention is to address the shortcomings of current monitoring methods for critical units, which are unable to effectively evaluate the degree of deterioration of in-use turbine oil, provide early warnings and interventions for deterioration, and thus fail to meet the company's requirements for predictive lubrication maintenance of critical units. To solve these problems, this invention provides a rapid assessment method for the degree of deterioration of in-use turbine oil in large rotating machinery of refining and chemical plants. This method uses a Fourier transform infrared spectrometer to perform infrared spectral scanning on both in-use turbine oil and new drummed oil in large rotating machinery, obtaining wavelengths at 4000 cm⁻¹. -1 Up to 550cm -1 The infrared spectrum of the range is used to assess the degree of degradation of the in-use turbine oil by comparing the infrared spectra of the in-use turbine oil and the new oil in the drum. This mainly includes a comprehensive comparative analysis of the content of phenolic antioxidants and oxidation degradation products in the lubricating oil.

[0042] Example 11: The specific implementation steps of this rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy are as follows: This invention identifies the degree of degradation of ketone carbonyl-based degradation products generated after oxidation of turbine oil in large rotating machinery by measuring the absorbance at the corresponding infrared wavelength, based on a wavelength of 1760 cm⁻¹. -1 Up to 1660cm -1 The change rate of ketone carbonyl degradation products was obtained by measuring the area of ​​the infrared absorption peak at a certain point.

[0043] Infrared spectral analysis was performed on the turbine oil used in the large rotating machinery to be tested. Based on the infrared absorption data, the wavelength of the turbine oil used in the large rotating machinery to be tested at 1760 cm⁻¹ was obtained. -1 Up to 1660cm -1 The infrared absorption peak area S1 is within the range.

[0044] Infrared spectral analysis was performed on the same type of new oil in drums as the steam turbine in use in the large rotating machinery to be tested. Based on the infrared absorption data, the new oil in drums was found to have an absorption rate of 1760 cm⁻¹. -1 Up to 1660cm -1 The infrared absorption peak area S0 is within the range.

[0045] The rate of change of the infrared absorption peak area of ​​the deteriorated products generated by the oxidation reaction of the turbine oil in the large rotating machinery under test is calculated as the rate of change of deteriorated products in the oil under test, ΔS, i.e., ΔS = (S1 - S0) / S0.

[0046] This invention utilizes phenolic antioxidants in turbine oil at 3650 cm⁻¹ -1 Up to 3651cm -1 The change in the absorption peak height at a given location is used to identify the rate of change in the content of phenolic antioxidants.

[0047] Based on the infrared spectral analysis data of the turbine oil in use and the new drum oil of the same type for the large rotating machinery under test, the infrared spectra of the turbine oil in use and the new drum oil of the same type for the large rotating machinery under test at 3650 cm⁻¹ were obtained. -1 Up to 3651cm -1 The highest absorption peak heights H0 and H1 are at these locations.

[0048] Calculate the rate of change of antioxidant content in the tested engine oil ΔH: ΔH = (H0 - H1) / H0 × 100%.

[0049] The degree of deterioration of the turbine oil in large rotating machinery is assessed by combining ΔH and ΔS. When ΔH ≥ 75% and ΔS ≥ 50%, the turbine oil in the large rotating machinery under test shows obvious deterioration and needs to be replaced with some new oil online.

[0050] After replacing 25% to 40% of the oil with new turbine oil in large rotating machinery online for 24 hours, infrared spectroscopy was performed on the replaced oil sample, obtaining wavelengths at 4000 cm⁻¹. -1 Up to 550cm -1 Infrared spectra of the replaced oil sample were obtained at 1760 cm⁻¹. -1 Up to 1660cm -1 The infrared absorption peak area S2 at 3650 cm⁻¹ and the oil sample after displacement are similar. -1 Up to 3651cm -1 The highest absorption peak height H2 at that location; Calculate the rate of change of deterioration products in the used turbine oil after replacement, ΔS': ΔS' = (S2 - S0) / S0 × 100%.

[0051] Calculate the rate of change of antioxidant content in the tested engine oil after replacement, ΔH': ΔH' = (H0 - H2) / H0 × 100%.

[0052] In the formula, H0 is the highest absorption peak height of the new oil in the second absorption band, and H2 is the highest absorption peak height of the replaced oil in the second absorption band.

[0053] By comprehensively evaluating ΔH' and ΔS', confirm whether the online replacement of part of the oil has achieved the desired effect. If the effect has not been achieved, continue to replace 25% to 40% of the oil online with new oil until ΔH' < 75% and ΔS' < 50%.

[0054] Example 12: The implementation process of this rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy is as follows: (1) Obtain the infrared spectrum of a brand of turbine oil, L-TSA32, in a drum, from the No. 2 generator unit of the thermal power plant's power generation operation department: The liquid pool method was used, with a liquid pool thickness of 0.1 mm and a spectral range of 4000 cm⁻¹. -1 Up to 550cm -1 According to the national standard GB / T 4756-2015 Manual Sampling Method for Petroleum Liquids, samples of new oil in L-TSA32 drums were taken, and the sampling location, sample name, batch number, sampling date, and other information were noted. The infrared spectrum of the new oil sample was obtained using an infrared spectrometer with absolute standardization function. Figure 1 This is to ensure the consistency of the infrared spectrum of the new oil samples in the barrel.

[0055] (2) Obtain the infrared spectrum of the turbine oil L-TSA32 (i.e., the test oil 1) in use for generator set No. 2 of the thermal power plant: The turbine oil in use for generator set No. 2 was sampled according to the national standard GB / T 4756-2015 Manual Sampling Method for Petroleum Liquids. The sampling location, sample name, sampling date and other information were noted. The infrared spectrum of the turbine oil sample was obtained using an infrared spectrometer with absolute standardization function. Figure 2 This is to ensure the consistency of the infrared spectra of in-use turbine oil samples.

[0056] (3) Calculate the rate of change of deterioration products in the tested engine oil: choose Figure 1 Medium wavelength 1760cm -1 Up to 1660cm -1 Based on the infrared absorption data of the range, the absorption of new oil at a wavelength of 1760 cm⁻¹ was calculated. -1 Up to 1660cm -1 The area of ​​the infrared absorption peak inside is S0; choose Figure 2 Medium wavelength 1760cm -1 Up to 1660cm -1 Based on the infrared absorption data of the range, the absorption of the tested engine oil 1 at a wavelength of 1760 cm⁻¹ was calculated. -1Up to 1660cm -1 The area of ​​the infrared absorption peak within the core is S1; The change rate of deterioration products in the tested engine oil is calculated as ΔS = (S1 - S0) / S0 × 100% = 65.5%.

[0057] (4) Calculate the rate of change of antioxidant content in the tested engine oil: choose Figure 1 Mid-wavelength 3650cm -1 Up to 3651cm -1 Based on the infrared absorption data of the range, the absorption of new oil at a wavelength of 3650 cm⁻¹ was calculated. -1 Up to 3651cm -1 The height of the highest infrared absorption peak at H0 is; choose Figure 2 Mid-wavelength 3650cm -1 Up to 3651cm -1 Based on the infrared absorption data of the range, the absorption of the tested engine oil 1 at a wavelength of 3650 cm⁻¹ was calculated. -1 Up to 3651cm -1 The height of the highest infrared absorption peak at H1 is; Calculate the rate of change of antioxidant content in the tested engine oil ΔH: ΔH = (H0 - H1) / H0 × 100% = 81.9%.

[0058] (5) Deterioration level assessment: In this embodiment, △H≥75% and △S≥50%, the turbine oil L-TSA32 used in the No. 2 generator unit of the power generation operation department of the thermal power plant has deteriorated significantly and needs to be replaced with some new oil online.

[0059] Example 13: The implementation process of this rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy is as follows: (1) Obtain the infrared spectrum of a new L-TSA46 drum of a certain brand of turbine oil (denoted as new oil 2) from generator unit No. 1 of the combined operation department of the thermal power plant: The liquid pool method was used, with a liquid pool thickness of 0.1 mm and a spectral range of 4000 cm⁻¹. -1 Up to 550cm -1 According to the national standard GB / T 4756-2015 Manual Sampling Method for Petroleum Liquids, samples of new oil in L-TSA46 drums were taken, and the sampling location, sample name, batch number, sampling date, and other information were noted. The infrared spectrum of the new oil sample was obtained using an infrared spectrometer with absolute standardization function. Figure 3 This is to ensure the consistency of the infrared spectrum of the new oil samples in the barrel.

[0060] (2) Obtain the infrared spectrum of the turbine oil L-TSA46 (denoted as test oil 2) in use of generator set No. 1 in the combined operation department of the thermal power plant: The turbine oil in use of generator set No. 1 was sampled according to the national standard GB / T 4756-2015 Manual Sampling Method for Petroleum Liquids, and the sampling location, sample name, sampling date and other information were noted. The infrared spectrum of the turbine oil sample was obtained using an infrared spectrometer with absolute standardization function. Figure 4 This is to ensure the consistency of the infrared spectra of in-use turbine oil samples.

[0061] (3) Calculate the rate of change of deterioration products in the tested engine oil: choose Figure 3 Medium wavelength 1760cm -1 Up to 1660cm -1 Based on the infrared absorption data of the range, the absorption of new oil 2 at a wavelength of 1760 cm⁻¹ was calculated. -1 Up to 1660cm -1 The area of ​​the infrared absorption peak inside is S0; choose Figure 4 Medium wavelength 1760cm -1 Up to 1660cm -1 Based on the infrared absorption data of the range, the absorption of the tested oil 2 at a wavelength of 1760 cm⁻¹ was calculated. -1 Up to 1660cm -1 The area of ​​the infrared absorption peak within the core is S1; The change rate of deterioration products in the tested engine oil is calculated as ΔS = (S1 - S0) / S0 × 100% = 35.2%. (4) Calculate the rate of change of antioxidant content in the tested engine oil: choose Figure 2 Mid-wavelength 3650cm -1 Up to 3651cm -1 Based on the infrared absorption data of the range, the absorption of new oil 2 at a wavelength of 3650 cm⁻¹ was calculated. -1 Up to 3651cm -1 The height of the highest infrared absorption peak at H0 is; choose Figure 3 Mid-wavelength 3650cm -1 Up to 3651cm -1 Based on the infrared absorption data of the range, the absorption of the tested oil 2 at a wavelength of 3650 cm⁻¹ was calculated. -1 Up to 3651cm -1 The height of the highest infrared absorption peak at H1 is; Calculate the rate of change of antioxidant content in the tested engine oil ΔH: ΔH = (H0 - H1) / H0 × 100% = 70.4%.

[0062] (5) Deterioration level assessment: In this embodiment, △H < ​​75% and △S < 50%, the turbine oil L-TSA46 (tested oil 2) used in the No. 1 generator unit of the combined operation department of the thermal power plant did not show obvious deterioration, and continued to be monitored regularly.

[0063] In summary, the rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy of the present invention is characterized by its simple steps and strong applicability. Compared with existing evaluation methods, the method of the present invention has significant advantages such as requiring less sample, high accuracy, and fast detection speed. This invention provides reliable technical support for the quantitative evaluation of the degree of degradation of in-use turbine oil in large rotating machinery of refining and chemical plants, effectively ensuring the long-term, safe, and stable operation of the plants.

[0064] The above technical features constitute various embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy, characterized in that... Includes the following steps: S1, based on the infrared absorption data of the test oil and new oil at the first absorption band, the change rate ΔS of deterioration products in the test oil is obtained; S2, based on the infrared absorption data of the test oil and new oil in the second absorption band, the change rate ΔH of antioxidant content in the test oil is obtained; S3, when △H≥N and △S≥M, it is determined that the test oil has deteriorated significantly, where N and M are the judgment thresholds; The oil to be tested is a turbine oil used in large rotating machinery, and the new oil is a new oil in a barrel of the same type as the turbine oil used in large rotating machinery.

2. The rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy according to claim 1, characterized in that... Before step S1, the following is also included: S0, perform infrared spectral analysis on the test oil and new oil to obtain infrared absorption data of the test oil and the new oil.

3. The rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy according to claim 1 or 2, characterized in that... Also includes: S4. For engine oils that show significant deterioration, partially replace the oil with new oil online. S5, perform infrared spectral scanning on the replaced engine oil to obtain infrared absorption data of the replaced engine oil in the first absorption band and the second absorption band. S6. Based on the infrared absorption data of the replaced test oil and the new oil at the first absorption band and the second absorption band, the change rate of deterioration products △S' and the change rate of antioxidant content △H' in the replaced test oil are obtained. S7. If △H' < N and △S' < M, then resume use; otherwise, repeat steps S4 to S6 until △H' < N and △S' < M.

4. The rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy according to any one of claims 1 to 3, characterized in that... The first absorption band has a wavelength of 1760 cm⁻¹ -1 Up to 1660cm -1 .

5. The rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy according to any one of claims 1 to 4, characterized in that... The second absorption band has a wavelength of 3650 cm⁻¹ -1 Up to 3651cm -1 .

6. The rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy according to any one of claims 1 to 5, characterized in that... Step S2 includes: Based on the infrared absorption data of the test oil and new oil in the first absorption band, the infrared absorption peak area of ​​the test oil and new oil in the first absorption band is calculated to obtain the change rate ΔS of deterioration products in the test oil. The rate of change of degradation products ΔS in the tested engine oil is calculated using the following formula: △S = (S1 - S0) / S0 × 100% In the formula, S0 is the infrared absorption peak area in the first absorption band of the new oil, and S1 is the infrared absorption peak area in the first absorption band of the oil to be tested.

7. The rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy according to any one of claims 1 to 6, characterized in that... Step S3 includes: Based on the infrared absorption data of the test oil and new oil in the second absorption band, the height of the highest absorption peak of the test oil and new oil in the second absorption band is obtained, and the change rate of antioxidant content ΔH in the test oil is calculated. The rate of change ΔH of antioxidant content in the tested engine oil is calculated using the following formula: △H = (H0 - H1) / H0 × 100% In the formula, H0 is the highest absorption peak height of the new oil in the second absorption band, and H1 is the highest absorption peak height of the oil under test in the second absorption band.

8. The rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy according to claim 3, characterized in that... In step S4, 25% to 40% of the oil is replaced online with new oil.

9. The rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy according to claim 3 or 8, characterized in that... Step S6 includes: Based on the infrared absorption peak areas of the replaced test oil and the new oil in the first absorption band, the change rate ΔS' of deterioration products in the replaced test oil and the change rate ΔS' of deterioration products in the used turbine oil of the replaced test oil are obtained, and calculated using the following formula: △S' = (S2 - S0) / S0 × 100% In the formula, S0 is the infrared absorption peak area in the first absorption band of the new oil, and S2 is the infrared absorption peak area in the first absorption band of the replaced oil to be tested. Based on the highest absorption peak heights of the replaced test oil and the new oil in the second absorption band, the change rate ΔH' of the antioxidant content in the replaced test oil is obtained. The change rate ΔH' of the antioxidant content in the replaced test oil is calculated using the following formula: △H' = (H0 - H2) / H0 × 100% In the formula, H0 is the highest absorption peak height of the new oil in the second absorption band, and H2 is the highest absorption peak height of the replaced oil in the second absorption band.

10. The rapid assessment method for the degree of degradation of in-use turbine oil based on infrared spectroscopy according to any one of claims 1 to 9, characterized in that... N is 75%, M is 50%.

Images