The inspection of engine lubricating oil can give an indication of the internal condition of an engine. By means of the Object-Oriented Programming (OOP), an expert system is developed in this paper to computerize the...The inspection of engine lubricating oil can give an indication of the internal condition of an engine. By means of the Object-Oriented Programming (OOP), an expert system is developed in this paper to computerize the inspection. The traditional components of an expert system, such us knowledge base, inference engine and user interface are reconstructed and integrated, based on the Microsoft Foundation Class (MFC) library. To testify the expert system, an inspection example is given at the end of this paper.展开更多
To overcome the limitations of traditional experimental“trial and error”methods in lubricant additive design,a new molecular design method based on molecular structure parameters is established here.The molecular me...To overcome the limitations of traditional experimental“trial and error”methods in lubricant additive design,a new molecular design method based on molecular structure parameters is established here.The molecular mechanism of the antioxidant reaction of hindered phenol,diphenylamine,and alkyl sulfide are studied via molecular simulations.Calculation results show that the strong electron-donating ability and high hydrogen-donating activity of the antioxidant molecule and the low hydrogen-abstracting activity of free radicals formed after dehydrogenation are the internal molecular causes of the shielding of phenol and diphenylamine from scavenging peroxy free radicals,and the strong electron-donating ability is the internal molecular cause of the high activity of thioether in decomposing alkyl hydrogen peroxide.Based on this antioxidant molecular mechanism,a molecular design rule of antioxidant is proposed,namely“high EHOMO,large Q(S),low bond dissociation energy BDE(O—H)and BDE(N—H)”.Two new antioxidants,PAS-I and PAS-II,are designed and prepared by chemical bonding of hindered phenol,diphenylamine,and sulfur atoms.Experimental results show that these antioxidants both have excellent antioxidant effects in lubricating oil,and that PAS-II is the superior antioxidant,consistent with theoretical predictions.展开更多
To address the problem of identifying multiple types of additives in lubricating oil,a method based on midinfrared spectral band selection using the eXtreme Gradient Boosting(XGBoost)algorithm combined with the ant co...To address the problem of identifying multiple types of additives in lubricating oil,a method based on midinfrared spectral band selection using the eXtreme Gradient Boosting(XGBoost)algorithm combined with the ant colony optimization(ACO)algorithm is proposed.The XGBoost algorithm was used to train and test three additives,T534(alkyl diphenylamine),T308(isooctyl acid thiophospholipid octadecylamine),and T306(trimethylphenol phosphate),separately,in order to screen for the optimal combination of spectral bands for each additive.The ACO algorithm was used to optimize the parameters of the XGBoost algorithm to improve the identification accuracy.During this process,the support vector machine(SVM)and hybrid bat algorithms(HBA)were included as a comparison,generating four models:ACO-XGBoost,ACO-SVM,HBA-XGboost,and HBA-SVM.The results showed that all four models could identify the three additives efficiently,with the ACO-XGBoost model achieving 100%recognition of all three additives.In addition,the generalizability of the ACO-XGBoost model was further demonstrated by predicting a lubricating oil containing the three additives prepared in our laboratory and a collected sample of commercial oil currently in use。展开更多
Due to increasingly stricter emissions on particulate matter(PM)emissions,diesel particulate filter(DPF)regeneration has become the most widely used and effective technology to reduce PM emissions.However,using incyli...Due to increasingly stricter emissions on particulate matter(PM)emissions,diesel particulate filter(DPF)regeneration has become the most widely used and effective technology to reduce PM emissions.However,using incylinder post-injection-based active DPF regeneration can increase engine oil dilution,thus affecting engine lubrication.Using a 4-cylinder turbocharged direct-injection diesel engine,this study analyzed the effect of lubricating oil on the formation and properties of turbocharger compressor soot deposits associated with engine oil dilution.Three diesel engine lubricating oils(CJ-4,CK-4,and CJ-4*)were selected,with each subjected to 200 hours of engine bench testing at 8%oil dilution.The composition of CJ-4*was the same as that of CJ-4 but with reduced amount of additives.Soot deposits were collected and analyzed.A merit calculation method was established to rate turbocharger deposits.Transmission electron microscopy,Raman spectroscopy,Fourier transform infrared spectroscopy,and thermogravimetric analysis(TGA)were used to characterize the morphology and composition of soot samples.The results showed that turbocharger deposits from CJ-4 and CK-4 were less than that from CJ-4*.The deposits from CJ-4*showed a more disordered morphology,whereas those from CJ-4 and CK-4 exhibited a higher degree of order.TGA results showed that the soluble organic fraction content in the deposit derived from CJ-4*was much higher than that obtained from CJ-4 and CK-4.展开更多
In order to enhance the tribological properties of lubricating oil, suitable surfactants such as Tween-20, Tween-60, Span-20 and Sodium sodecylbenzenesulfonate were selected and lubricating oils containing CeO2 and Ti...In order to enhance the tribological properties of lubricating oil, suitable surfactants such as Tween-20, Tween-60, Span-20 and Sodium sodecylbenzenesulfonate were selected and lubricating oils containing CeO2 and TiO2 nanoparticles were prepared. The morphology and size of CeO2 and TiO2 nanoparticles were examined with a transmission electron microscope （TEM）. The tribological properties of the oils were tested using an MRS-1J four-ball tribotester. The research results show that when the proportion by weight of CeO2 nanoparticles to TiO2 nanoparticles is 1：3, and the total weight fraction is 0.6%, the lubricating oil has optimal anti-wear and friction reducing properties. The addition of CeO2 nanoparticles reduces the required amount of TiO2 nanoparticles.展开更多
The design and fabrication of high toughness electromagnetic interference(EMI)shielding composite films with diminished reflection are an imperative task to solve electromagnetic pollution problem.Ternary MXene/ANF(ar...The design and fabrication of high toughness electromagnetic interference(EMI)shielding composite films with diminished reflection are an imperative task to solve electromagnetic pollution problem.Ternary MXene/ANF(aramid nanofibers)–MoS_(2)composite films with nacre-like layered structure here are fabricated after the introduction of MoS_(2)into binary MXene/ANF composite system.The introduction of MoS_(2)fulfills an impressive“kill three birds with one stone”improvement effect:lubrication toughening mechanical performance,reduction in secondary reflection pollution of electromagnetic wave,and improvement in the performance of photothermal conversion.After the introduction of MoS_(2)into binary MXene/ANF(mass ratio of 50:50),the strain to failure and tensile strength increase from 22.1±1.7%and 105.7±6.4 MPa and to 25.8±0.7%and 167.3±9.1 MPa,respectively.The toughness elevates from 13.0±4.1 to 26.3±0.8 MJ m^(−3)(~102.3%)simultaneously.And the reflection shielding effectiveness(SE_(R))of MXene/ANF(mass ratio of 50:50)decreases~10.8%.EMI shielding effectiveness(EMI SE)elevates to 41.0 dB(8.2–12.4 GHz);After the introduction of MoS_(2)into binary MXene/ANF(mass ratio of 60:40),the strain to failure increases from 18.3±1.9%to 28.1±0.7%(~53.5%),the SE_(R)decreases~22.2%,and the corresponding EMI SE is 43.9 dB.The MoS_(2)also leads to a more efficient photothermal conversion performance(~45 to~55℃).Additionally,MXene/ANF–MoS_(2)composite films exhibit excellent electric heating performance,quick temperature elevation(15 s),excellent cycle stability(2,2.5,and 3 V),and long-term stability(2520 s).Combining with excellent mechanical performance with high MXene content,electric heating performance,and photothermal conversion performance,EMI shielding ternary MXene/ANF–MoS_(2)composite films could be applied in many industrial areas.This work broadens how to achieve a balance between mechanical properties and versatility of composites in the case of high-function fillers.展开更多
The friction and wear characteristics of lauroyl glutamine, lauroyl glycine and lauroyl alanine, used as green additives in HVI 350 mineral lubricating oil, were evaluated on a four-ball tribotester. The morphologies ...The friction and wear characteristics of lauroyl glutamine, lauroyl glycine and lauroyl alanine, used as green additives in HVI 350 mineral lubricating oil, were evaluated on a four-ball tribotester. The morphologies and chemical species of the worn surfaces were analyzed by scanning electron microscope （SEM） and X-ray photoelectron spectroscope （XPS）, respectively. The test results indicated that the three fatty acyl amino acids could effectively improve the anti-wear and friction-reducing abilities of the HVI 350 mineral oil. The improvement in anti-wear and friction-reducing abilities of the mineral oil by the related amino acids was mainly ascribed to the formation of a composite boundary lubrication film due to the adsorption of amino acids on the friction surfaces.展开更多
In this paper,an ab initio,local density functional(LDF)method was used to explore the relationship between the molecular properties of additives and the lubricating performance of aluminum rolling oil.The structural ...In this paper,an ab initio,local density functional(LDF)method was used to explore the relationship between the molecular properties of additives and the lubricating performance of aluminum rolling oil.The structural properties of butyl stearate,dodecanol,docosanol,and methyl dodecanoate were studied according to the density functional theory.The calculated data showed that the atoms in or around the functional groups might be likely the reacting sites.Because of the different functional groups and structure of ester and alcohol,two types of complex additives,dodecanol and butyl stearate,methyl dodecanoate and butyl stearate,respectively,were chosen for studying their tribological properties and performing aluminum cold rolling experiments.The test results agreed with the calculated results very well.The complex ester,viz.methyl dodecanoate and butyl stearate,had the best lubricating performance with a friction coefficient of 0.084 1 and a permissive-rolling thickness of 0.040 mm as compared with that of dodecanol-butyl stearate-base oil formulation.展开更多
The optical properties of four kinds of lubricating greases （urea, lithium, extreme pressure lithium, molybdenum disulfide lithium greases） with different NLGL （National Lubricant Grease Institute of America） numb...The optical properties of four kinds of lubricating greases （urea, lithium, extreme pressure lithium, molybdenum disulfide lithium greases） with different NLGL （National Lubricant Grease Institute of America） numbers were investigated using terahertz time-domain spectroscopy. Greases with different NLGL grades have unique spectral features in the terahertz range. Comparison of the experimental data with predictions based on Lorentz Lorenz theory exhibited that the refractive indices of each kind of lubricating grease were dependent on the their consistency. In addition, molybdenum disullfide （MoS2） aa a libricant additive shows strong absorption from 0.2 to 1.4 THz, leading to higher absorption of MoS2-1ithium grease than that of lithium grease.展开更多
This paper presents a simulator model of a marine diesel engine based on physical, semi-physical, mathematical and thermodynamic equations, which allows fast predictive simulations The whole engine system is divided i...This paper presents a simulator model of a marine diesel engine based on physical, semi-physical, mathematical and thermodynamic equations, which allows fast predictive simulations The whole engine system is divided into several functional blocks： cooling, lubrication, air, injection, combustion and emissions. The sub-models and dynamic characteristics of individual blocks are established according to engine working principles equations and experimental data collected from a marine diesel engine test bench for SIMB Company under the reference 6M26SRP1. The overall engine system dynamics is expressed as a set of simultaneous algebraic and differential equations using sub-blocks and S-Functions of Matlab/Simulink. The simulation of this model, implemented on Matlab/Simulink has been validated and can be used to obtain engine performance, pressure, temperature, efficiency, heat release, crank angle, fuel rate, emissions at different sub-blocks. The simulator will be used, in future work, to study the engine performance in faulty conditions, and can be used to assist marine engineers in fault diagnosis and estimation （FDI） as well as designers to predict the behavior of the cooling system, lubrication system, injection system, combustion, emissions, in order to optimize the dimensions of different components. This program is a platform for fault simulator, to investigate the impact on sub-blocks engine＇s output of changing values for faults parameters such as： faulty fuel injector, leaky cylinder, worn fuel pump, broken piston rings, a dirty turbocharger, dirty air filter, dirty air cooler, air leakage, water leakage, oil leakage and contamination, fouling of heat exchanger, pumps wear, failure of injectors （and many others）.展开更多
Lubricating oils are usually produced by solvent extraction to separate aromatics in order to achieve the desired specifications and better quality products.Among the different properties of lubricating oils,density a...Lubricating oils are usually produced by solvent extraction to separate aromatics in order to achieve the desired specifications and better quality products.Among the different properties of lubricating oils,density and refractive index are some of the most important properties which can both be used for petroleum fluid characterization.Predictions of density and refractive index for naphthenic oils during solvent extraction by DMSO obtained by the pseudo-component approach and the quadratic correlation were both examined.The pseudo-component approach is a method to predict density and refractive index from composition while the latter merely relates density to refractive index.Results indicated that the predictions yielded by the pseudo-component method were in good agreement with experimental data for naphthenic oils.And the use of a function of refractive index(FRI_(20))as a pseudo-component property remarkably improved n_(20)predictions for the naphthenic mixtures.However,the density and refractive index predictions obtained by the quadratic correlation exhibited significantly higher de-viations for naphthenic oils than those for paraffinic oils.Thus a new modified correlation of the same functional form was proposed for naphthenic oils.The modification significantly improved predictions for naphthenic oils,which presented similar accuracy as the pseudo-component approach.And the previous correlation was still used for paraffinic oils.Additionally,effect of temperature on density and refractive index of naphthenic oils was examined.Results showed that the modified quadratic correlation was accurate for describing the relationship between density and refractive index of naphthenic oils at 20-90℃.The temperature dependence of density and refractive index for the raffinates and the extracts could be accurately described by the thermal coefficients for saturates and aromatics,respectively.Regarding the refractive index variation of the extracts with temperature,the empirical equation was proved to be a better option compared with the method using the thermal coefficient for aromatics.展开更多
A kind of vacuum lubricating grease was prepared by using perfluoropolyether as base oil,perfluorinated polymer as thickener,and self-made additives.The colloidal stability of the grease was greatly improved by introd...A kind of vacuum lubricating grease was prepared by using perfluoropolyether as base oil,perfluorinated polymer as thickener,and self-made additives.The colloidal stability of the grease was greatly improved by introducing a colloidal structure modifier.The rheological properties of the self-made grease(SMG),such as viscosity versus time,thixotropy,etc.,were studied by a rheometer at different temperatures and were compared with those of foreign brand grease(FBG).The results show that the performance of SMG reached the level of similar FBG,and some properties such as mechanical stability,colloidal stability,extreme pressure and antiwear properties were better.It can be used for long life lubrication of moving parts in a vacuum environment.展开更多
The influence of the ratio and content of emulsifiers on the stability of anion emulsions for cold strip rolling was investigated in this paper. The present study also investigated the effects of HLB （hydrophile-lipo...The influence of the ratio and content of emulsifiers on the stability of anion emulsions for cold strip rolling was investigated in this paper. The present study also investigated the effects of HLB （hydrophile-lipophile balance） value and emulsifier content on the stability of no-ionic emulsions. Based on the effects of different stabilities and different concentrations of emulsions on the adsorptivity and friction coefficients, good lubricating performance was obtained when the amount of the separated oil and soap （SOS） accounted for 2.5%. The wearing scar of the steel balls also indicated the improvements in tribological properties after using the emulsion. Thus, the preparation of emulsion should be regulated according to different rolling conditions.展开更多
To meet the requirements for high aromatic content and low polycyclic aromatic(PCA)concentration,eco-friendly aromatic-rich rubber extender oils are usually produced by two-stage solvent extraction processes with furf...To meet the requirements for high aromatic content and low polycyclic aromatic(PCA)concentration,eco-friendly aromatic-rich rubber extender oils are usually produced by two-stage solvent extraction processes with furfural.Among the different properties of rubber processing oils,density and refractive index are some of the most important properties related to their final quality.Two types of methods,including a pseudo-component approach by using mixing rules and several correlations,were used for calculation of density and refractive index at 20℃ of paraffinic furfural-extract oils and their secondary raffinates.Results indicated that similar accuracy was obtained for predicting the density and the refractive index of furfural+furfural-extract paraffinic oil systems.However,the quadratic correlation presents its advantage over the pseudo-component approach when the composition of oils is not available.Moreover,the quadratic correlation was also used for naphthenic lubricating oils during two-stage solvent extraction processes.The predictions showed much larger discrepancies with respect to experimental values than those of paraffinic lubricating oils,which indicated that the quadratic correlation was more suitable for paraffinic oils with a CN value of below 37%.展开更多
Appropriate base oils and homologous additives such as extreme pressure and anti-wear agents,oiliness agents and antioxidants were selected,and experiments testing the compatibility performance between additive,base o...Appropriate base oils and homologous additives such as extreme pressure and anti-wear agents,oiliness agents and antioxidants were selected,and experiments testing the compatibility performance between additive,base oil and other components were carried out to develop the SK and SD series of rolling oils for cold rolling of stainless steel.The developed oils were used in the stainless steel cold rolling lubrication experiments,and were successfully applied in the actual cold rolling operation of stainless steel.Compared with a foreign product,the tribological properties,the thermal oxidation stability,and the rolling lubrication performance of the developed stainless steel cold rolling oils were studied.Test results showed that the tribological properties of the thereby developed rolling oils and the reference one were almost at the same level,and to some extent the performance of rolling was even better than the foreign product,at the same time the stainless steel sheet could retain its well annealed performance.Meanwhile,within a certain range,the lubrication of the rolling oil became better as its viscosity increased at the same level of saponification value,which could provide a lower friction coefficient,so that a higher maximum reduction ratio of the rolled piece through a constant roll gap and a minimum thickness could be secured.Also,similar phenomena appeared as the saponification value increased at a same viscosity level of the rolling oils.展开更多
Thrust bearing is a key component of the propulsion system of a ship. It transfers the propulsive forces from the propeller to the ship＇s hull, allowing the propeller to push the ship ahead. The performance of a thru...Thrust bearing is a key component of the propulsion system of a ship. It transfers the propulsive forces from the propeller to the ship＇s hull, allowing the propeller to push the ship ahead. The performance of a thrust bearing pad is critical. When the thrust bearing becomes damaged, it can cause the ship to lose power and can also affect its operational safety. For this paper, the distribution of the pressure field of a thrust pad was calculated with numerical method, applying Reynolds equation. Thrust bearing properties for loads were analyzed, given variations in outlet thickness of the pad and variations between the load and the slope of the pad. It was noticed that the distribution of pressure was uneven. As a result, increases of both the outlet thickness and the slope coefficient of the pad were able to improve load beating capability.展开更多
In order to solve the hardening problem of complex calcium lubricating grease, the water absorption test of several calcium salts was carried out, and it was found that calcium 12-hydroxystearate did not absorb water,...In order to solve the hardening problem of complex calcium lubricating grease, the water absorption test of several calcium salts was carried out, and it was found that calcium 12-hydroxystearate did not absorb water, and calcium acetate, calcium phosphate and calcium borate had different degrees of water absorption. Calcium acetate has the highest water absorption rate, while calcium phosphate and calcium borate show comparable water absorption rates. Upon using the molecular simulation technology, it is found that in the complex calcium grease system, calcium phosphate and calcium borate tend to combine with water, which inhibits the water absorption of calcium acetate and alleviate the hardening problem.展开更多
A new kind of emulsion containing nano TiO_2 was developed through the dispersion experiment. A commercial emulsion and a prepared by our lab emulsion without nano particles were chosen as controls to test the tribolo...A new kind of emulsion containing nano TiO_2 was developed through the dispersion experiment. A commercial emulsion and a prepared by our lab emulsion without nano particles were chosen as controls to test the tribological and antibacterial properties of this new emulsion. The load carrying capacity, friction coefficient and average diameter of wear scars were tested by a four-ball machine and the comprehensive antifriction parameter ω was calculated. The wetting angle was also tested using a JC200C1 wetting angle tester. The micro surface and roughness of rolled strips were analyzed to investigate the tribological performance of the recommended new emulsion in strip production. It is shown that the new nano-emulsion possesses a higher load carrying capacity and wetting ability. Therefore the abrasive/plowing wear is reduced more efficiently with the addition of nano particles, and the micro surface is improved. The density of bacteria in the emulsions was tested after the cold rolling experiment. The emulsion breaking ratio and bacteria density were also tested in different time intervals after the cold rolling experiment. The final p H values and bacteria density of different layers of emulsions were measured and the sediment was analyzed by TEM to evaluate the antibacterial behavior of this new emulsion. It is shown that the density of microbial colonies which led to a corruption of emulsions was decreased about 90% and the effective antibacterial period was prolonged.展开更多
Tribological properties of 150 SN mineral oil and the oils doped with different contents of zinc butyloctyldithiophosphate(T202) under magnetic field or non-magnetic field were evaluated on a four-ball tribotester by ...Tribological properties of 150 SN mineral oil and the oils doped with different contents of zinc butyloctyldithiophosphate(T202) under magnetic field or non-magnetic field were evaluated on a four-ball tribotester by applying an external magnetic field around the friction region. Moreover, the morphology and the tribochemical characteristics of worn surfaces were examined by a scanning electron microscope(SEM) and an X-ray photoelectron spectrometer(XPS). Then the lubrication mechanisms were discussed. The tribological test results indicated that the wear scar diameters(WSDs) of steel balls lubricated by the T202-containing lubricating oils and the friction coefficients of the corresponding oil under magnetic field were smaller than those without magnetic affection. The worn surface lubricated with the T202-formulated oils in a magnetic field was smoother than that obtained under the normal condition. Furthermore, the results of XPS analysis indicated that tribochemical films on the surfaces lubricated with T202-doped oils were mainly composed of compounds such as FeSO_4, FeS and ZnS. The atomic concentrations of oxygen, sulfur, iron, zinc and phosphorus species identified in T202 under magnetic field were higher than those without magnetic impact. It can be inferred that the improved anti-wear and friction-reducing ability of T202-doped oils was attributed to the promoted tribochemical reactions and the modification of the worn surfaces induced by magnetic field.展开更多
The factors affecting the developmcnt of Sinopec lubricating oil were analyzed in this paper, and an analytic hierarchy process （AHP） model for selecting lubricating-oil producing bases was developed. By using this ...The factors affecting the developmcnt of Sinopec lubricating oil were analyzed in this paper, and an analytic hierarchy process （AHP） model for selecting lubricating-oil producing bases was developed. By using this model, nine lubricating oil producing companies under Sinopec were comprehensively evaluated. The evaluation result showed that the Maoming Lubricating Oil Company （Guangdong province）, Jingmen Lubricating Oil Company （Hubei province） and Changcheng Lube Oil Company （Beijing） are top three choices, and should be developed preferentially for the development of Sinopec producing bases of lubricating oil in the future. The conclusions provide the theoretical basis for selecting lubricating oil producing bases for decision makers.展开更多
文摘The inspection of engine lubricating oil can give an indication of the internal condition of an engine. By means of the Object-Oriented Programming (OOP), an expert system is developed in this paper to computerize the inspection. The traditional components of an expert system, such us knowledge base, inference engine and user interface are reconstructed and integrated, based on the Microsoft Foundation Class (MFC) library. To testify the expert system, an inspection example is given at the end of this paper.
文摘To overcome the limitations of traditional experimental“trial and error”methods in lubricant additive design,a new molecular design method based on molecular structure parameters is established here.The molecular mechanism of the antioxidant reaction of hindered phenol,diphenylamine,and alkyl sulfide are studied via molecular simulations.Calculation results show that the strong electron-donating ability and high hydrogen-donating activity of the antioxidant molecule and the low hydrogen-abstracting activity of free radicals formed after dehydrogenation are the internal molecular causes of the shielding of phenol and diphenylamine from scavenging peroxy free radicals,and the strong electron-donating ability is the internal molecular cause of the high activity of thioether in decomposing alkyl hydrogen peroxide.Based on this antioxidant molecular mechanism,a molecular design rule of antioxidant is proposed,namely“high EHOMO,large Q(S),low bond dissociation energy BDE(O—H)and BDE(N—H)”.Two new antioxidants,PAS-I and PAS-II,are designed and prepared by chemical bonding of hindered phenol,diphenylamine,and sulfur atoms.Experimental results show that these antioxidants both have excellent antioxidant effects in lubricating oil,and that PAS-II is the superior antioxidant,consistent with theoretical predictions.
基金the Beijing Natural Science Foundation(Grant No.2232066)the Open Project Foundation of State Key Laboratory of Solid Lubrication(Grant LSL-2212).
文摘To address the problem of identifying multiple types of additives in lubricating oil,a method based on midinfrared spectral band selection using the eXtreme Gradient Boosting(XGBoost)algorithm combined with the ant colony optimization(ACO)algorithm is proposed.The XGBoost algorithm was used to train and test three additives,T534(alkyl diphenylamine),T308(isooctyl acid thiophospholipid octadecylamine),and T306(trimethylphenol phosphate),separately,in order to screen for the optimal combination of spectral bands for each additive.The ACO algorithm was used to optimize the parameters of the XGBoost algorithm to improve the identification accuracy.During this process,the support vector machine(SVM)and hybrid bat algorithms(HBA)were included as a comparison,generating four models:ACO-XGBoost,ACO-SVM,HBA-XGboost,and HBA-SVM.The results showed that all four models could identify the three additives efficiently,with the ACO-XGBoost model achieving 100%recognition of all three additives.In addition,the generalizability of the ACO-XGBoost model was further demonstrated by predicting a lubricating oil containing the three additives prepared in our laboratory and a collected sample of commercial oil currently in use。
基金financially supported by SINOPEC(Grant No.124015)。
文摘Due to increasingly stricter emissions on particulate matter(PM)emissions,diesel particulate filter(DPF)regeneration has become the most widely used and effective technology to reduce PM emissions.However,using incylinder post-injection-based active DPF regeneration can increase engine oil dilution,thus affecting engine lubrication.Using a 4-cylinder turbocharged direct-injection diesel engine,this study analyzed the effect of lubricating oil on the formation and properties of turbocharger compressor soot deposits associated with engine oil dilution.Three diesel engine lubricating oils(CJ-4,CK-4,and CJ-4*)were selected,with each subjected to 200 hours of engine bench testing at 8%oil dilution.The composition of CJ-4*was the same as that of CJ-4 but with reduced amount of additives.Soot deposits were collected and analyzed.A merit calculation method was established to rate turbocharger deposits.Transmission electron microscopy,Raman spectroscopy,Fourier transform infrared spectroscopy,and thermogravimetric analysis(TGA)were used to characterize the morphology and composition of soot samples.The results showed that turbocharger deposits from CJ-4 and CK-4 were less than that from CJ-4*.The deposits from CJ-4*showed a more disordered morphology,whereas those from CJ-4 and CK-4 exhibited a higher degree of order.TGA results showed that the soluble organic fraction content in the deposit derived from CJ-4*was much higher than that obtained from CJ-4 and CK-4.
基金Supported by the Shanghai Municipal Education Commission(06FZ008)Shanghai Municipal Education Commission Key Disciplines(J50603)
文摘In order to enhance the tribological properties of lubricating oil, suitable surfactants such as Tween-20, Tween-60, Span-20 and Sodium sodecylbenzenesulfonate were selected and lubricating oils containing CeO2 and TiO2 nanoparticles were prepared. The morphology and size of CeO2 and TiO2 nanoparticles were examined with a transmission electron microscope （TEM）. The tribological properties of the oils were tested using an MRS-1J four-ball tribotester. The research results show that when the proportion by weight of CeO2 nanoparticles to TiO2 nanoparticles is 1：3, and the total weight fraction is 0.6%, the lubricating oil has optimal anti-wear and friction reducing properties. The addition of CeO2 nanoparticles reduces the required amount of TiO2 nanoparticles.
基金supported by the Talent Fund of Beijing Jiaotong University(No,2023XKRC015)the National Natural Science Foundation of China(Nos.52172081,52073010 and 52373259).
文摘The design and fabrication of high toughness electromagnetic interference(EMI)shielding composite films with diminished reflection are an imperative task to solve electromagnetic pollution problem.Ternary MXene/ANF(aramid nanofibers)–MoS_(2)composite films with nacre-like layered structure here are fabricated after the introduction of MoS_(2)into binary MXene/ANF composite system.The introduction of MoS_(2)fulfills an impressive“kill three birds with one stone”improvement effect:lubrication toughening mechanical performance,reduction in secondary reflection pollution of electromagnetic wave,and improvement in the performance of photothermal conversion.After the introduction of MoS_(2)into binary MXene/ANF(mass ratio of 50:50),the strain to failure and tensile strength increase from 22.1±1.7%and 105.7±6.4 MPa and to 25.8±0.7%and 167.3±9.1 MPa,respectively.The toughness elevates from 13.0±4.1 to 26.3±0.8 MJ m^(−3)(~102.3%)simultaneously.And the reflection shielding effectiveness(SE_(R))of MXene/ANF(mass ratio of 50:50)decreases~10.8%.EMI shielding effectiveness(EMI SE)elevates to 41.0 dB(8.2–12.4 GHz);After the introduction of MoS_(2)into binary MXene/ANF(mass ratio of 60:40),the strain to failure increases from 18.3±1.9%to 28.1±0.7%(~53.5%),the SE_(R)decreases~22.2%,and the corresponding EMI SE is 43.9 dB.The MoS_(2)also leads to a more efficient photothermal conversion performance(~45 to~55℃).Additionally,MXene/ANF–MoS_(2)composite films exhibit excellent electric heating performance,quick temperature elevation(15 s),excellent cycle stability(2,2.5,and 3 V),and long-term stability(2520 s).Combining with excellent mechanical performance with high MXene content,electric heating performance,and photothermal conversion performance,EMI shielding ternary MXene/ANF–MoS_(2)composite films could be applied in many industrial areas.This work broadens how to achieve a balance between mechanical properties and versatility of composites in the case of high-function fillers.
基金the financial support from National Natural Science Foundation of China(project No.50975282)Chongqing Science Foundation for Outstanding Youth(project No. CSTC2008,BA4037)
文摘The friction and wear characteristics of lauroyl glutamine, lauroyl glycine and lauroyl alanine, used as green additives in HVI 350 mineral lubricating oil, were evaluated on a four-ball tribotester. The morphologies and chemical species of the worn surfaces were analyzed by scanning electron microscope （SEM） and X-ray photoelectron spectroscope （XPS）, respectively. The test results indicated that the three fatty acyl amino acids could effectively improve the anti-wear and friction-reducing abilities of the HVI 350 mineral oil. The improvement in anti-wear and friction-reducing abilities of the mineral oil by the related amino acids was mainly ascribed to the formation of a composite boundary lubrication film due to the adsorption of amino acids on the friction surfaces.
基金the financial support of this study provided by the National Natural Science Foundation of China(No.51274037)the Cooperation Program between USTB and SINOPEC(No.112116)
文摘In this paper,an ab initio,local density functional(LDF)method was used to explore the relationship between the molecular properties of additives and the lubricating performance of aluminum rolling oil.The structural properties of butyl stearate,dodecanol,docosanol,and methyl dodecanoate were studied according to the density functional theory.The calculated data showed that the atoms in or around the functional groups might be likely the reacting sites.Because of the different functional groups and structure of ester and alcohol,two types of complex additives,dodecanol and butyl stearate,methyl dodecanoate and butyl stearate,respectively,were chosen for studying their tribological properties and performing aluminum cold rolling experiments.The test results agreed with the calculated results very well.The complex ester,viz.methyl dodecanoate and butyl stearate,had the best lubricating performance with a friction coefficient of 0.084 1 and a permissive-rolling thickness of 0.040 mm as compared with that of dodecanol-butyl stearate-base oil formulation.
基金Project supported by the New Century Excellent Talents in University(Grant No.NCET-08-0841)the National Natural Science Foundation of China(Grant Nos.60778034,60877038,and10804077)+2 种基金the Beijng Natural Science Foundation(Grant No.4082026)the Research Fund for the Doctoral Program of Higher Education(Grant No.200804250006)the State KeyLaboratory of Heavy Oil Processing,China University of Petroleum(Grant No.2008-14)
文摘The optical properties of four kinds of lubricating greases （urea, lithium, extreme pressure lithium, molybdenum disulfide lithium greases） with different NLGL （National Lubricant Grease Institute of America） numbers were investigated using terahertz time-domain spectroscopy. Greases with different NLGL grades have unique spectral features in the terahertz range. Comparison of the experimental data with predictions based on Lorentz Lorenz theory exhibited that the refractive indices of each kind of lubricating grease were dependent on the their consistency. In addition, molybdenum disullfide （MoS2） aa a libricant additive shows strong absorption from 0.2 to 1.4 THz, leading to higher absorption of MoS2-1ithium grease than that of lithium grease.
文摘This paper presents a simulator model of a marine diesel engine based on physical, semi-physical, mathematical and thermodynamic equations, which allows fast predictive simulations The whole engine system is divided into several functional blocks： cooling, lubrication, air, injection, combustion and emissions. The sub-models and dynamic characteristics of individual blocks are established according to engine working principles equations and experimental data collected from a marine diesel engine test bench for SIMB Company under the reference 6M26SRP1. The overall engine system dynamics is expressed as a set of simultaneous algebraic and differential equations using sub-blocks and S-Functions of Matlab/Simulink. The simulation of this model, implemented on Matlab/Simulink has been validated and can be used to obtain engine performance, pressure, temperature, efficiency, heat release, crank angle, fuel rate, emissions at different sub-blocks. The simulator will be used, in future work, to study the engine performance in faulty conditions, and can be used to assist marine engineers in fault diagnosis and estimation （FDI） as well as designers to predict the behavior of the cooling system, lubrication system, injection system, combustion, emissions, in order to optimize the dimensions of different components. This program is a platform for fault simulator, to investigate the impact on sub-blocks engine＇s output of changing values for faults parameters such as： faulty fuel injector, leaky cylinder, worn fuel pump, broken piston rings, a dirty turbocharger, dirty air filter, dirty air cooler, air leakage, water leakage, oil leakage and contamination, fouling of heat exchanger, pumps wear, failure of injectors （and many others）.
基金sponsored by the Natural Science Foundation of Xinjiang Uygur Autonomous Region(No.2022D01F37).
文摘Lubricating oils are usually produced by solvent extraction to separate aromatics in order to achieve the desired specifications and better quality products.Among the different properties of lubricating oils,density and refractive index are some of the most important properties which can both be used for petroleum fluid characterization.Predictions of density and refractive index for naphthenic oils during solvent extraction by DMSO obtained by the pseudo-component approach and the quadratic correlation were both examined.The pseudo-component approach is a method to predict density and refractive index from composition while the latter merely relates density to refractive index.Results indicated that the predictions yielded by the pseudo-component method were in good agreement with experimental data for naphthenic oils.And the use of a function of refractive index(FRI_(20))as a pseudo-component property remarkably improved n_(20)predictions for the naphthenic mixtures.However,the density and refractive index predictions obtained by the quadratic correlation exhibited significantly higher de-viations for naphthenic oils than those for paraffinic oils.Thus a new modified correlation of the same functional form was proposed for naphthenic oils.The modification significantly improved predictions for naphthenic oils,which presented similar accuracy as the pseudo-component approach.And the previous correlation was still used for paraffinic oils.Additionally,effect of temperature on density and refractive index of naphthenic oils was examined.Results showed that the modified quadratic correlation was accurate for describing the relationship between density and refractive index of naphthenic oils at 20-90℃.The temperature dependence of density and refractive index for the raffinates and the extracts could be accurately described by the thermal coefficients for saturates and aromatics,respectively.Regarding the refractive index variation of the extracts with temperature,the empirical equation was proved to be a better option compared with the method using the thermal coefficient for aromatics.
文摘A kind of vacuum lubricating grease was prepared by using perfluoropolyether as base oil,perfluorinated polymer as thickener,and self-made additives.The colloidal stability of the grease was greatly improved by introducing a colloidal structure modifier.The rheological properties of the self-made grease(SMG),such as viscosity versus time,thixotropy,etc.,were studied by a rheometer at different temperatures and were compared with those of foreign brand grease(FBG).The results show that the performance of SMG reached the level of similar FBG,and some properties such as mechanical stability,colloidal stability,extreme pressure and antiwear properties were better.It can be used for long life lubrication of moving parts in a vacuum environment.
基金supported by the National High-Tech Research and Development Program ("863"Program) of China(No.2009AA03Z 339)
文摘The influence of the ratio and content of emulsifiers on the stability of anion emulsions for cold strip rolling was investigated in this paper. The present study also investigated the effects of HLB （hydrophile-lipophile balance） value and emulsifier content on the stability of no-ionic emulsions. Based on the effects of different stabilities and different concentrations of emulsions on the adsorptivity and friction coefficients, good lubricating performance was obtained when the amount of the separated oil and soap （SOS） accounted for 2.5%. The wearing scar of the steel balls also indicated the improvements in tribological properties after using the emulsion. Thus, the preparation of emulsion should be regulated according to different rolling conditions.
文摘To meet the requirements for high aromatic content and low polycyclic aromatic(PCA)concentration,eco-friendly aromatic-rich rubber extender oils are usually produced by two-stage solvent extraction processes with furfural.Among the different properties of rubber processing oils,density and refractive index are some of the most important properties related to their final quality.Two types of methods,including a pseudo-component approach by using mixing rules and several correlations,were used for calculation of density and refractive index at 20℃ of paraffinic furfural-extract oils and their secondary raffinates.Results indicated that similar accuracy was obtained for predicting the density and the refractive index of furfural+furfural-extract paraffinic oil systems.However,the quadratic correlation presents its advantage over the pseudo-component approach when the composition of oils is not available.Moreover,the quadratic correlation was also used for naphthenic lubricating oils during two-stage solvent extraction processes.The predictions showed much larger discrepancies with respect to experimental values than those of paraffinic lubricating oils,which indicated that the quadratic correlation was more suitable for paraffinic oils with a CN value of below 37%.
文摘Appropriate base oils and homologous additives such as extreme pressure and anti-wear agents,oiliness agents and antioxidants were selected,and experiments testing the compatibility performance between additive,base oil and other components were carried out to develop the SK and SD series of rolling oils for cold rolling of stainless steel.The developed oils were used in the stainless steel cold rolling lubrication experiments,and were successfully applied in the actual cold rolling operation of stainless steel.Compared with a foreign product,the tribological properties,the thermal oxidation stability,and the rolling lubrication performance of the developed stainless steel cold rolling oils were studied.Test results showed that the tribological properties of the thereby developed rolling oils and the reference one were almost at the same level,and to some extent the performance of rolling was even better than the foreign product,at the same time the stainless steel sheet could retain its well annealed performance.Meanwhile,within a certain range,the lubrication of the rolling oil became better as its viscosity increased at the same level of saponification value,which could provide a lower friction coefficient,so that a higher maximum reduction ratio of the rolled piece through a constant roll gap and a minimum thickness could be secured.Also,similar phenomena appeared as the saponification value increased at a same viscosity level of the rolling oils.
基金Supported by the Natural Science Foundation of China under Grant No.50675162the Program of Introducing Talents of Discipline to Universities under Grant No.B08031the Key Project of Hubei Province Science & Technology Fund under Grant No.2008CAD027
文摘Thrust bearing is a key component of the propulsion system of a ship. It transfers the propulsive forces from the propeller to the ship＇s hull, allowing the propeller to push the ship ahead. The performance of a thrust bearing pad is critical. When the thrust bearing becomes damaged, it can cause the ship to lose power and can also affect its operational safety. For this paper, the distribution of the pressure field of a thrust pad was calculated with numerical method, applying Reynolds equation. Thrust bearing properties for loads were analyzed, given variations in outlet thickness of the pad and variations between the load and the slope of the pad. It was noticed that the distribution of pressure was uneven. As a result, increases of both the outlet thickness and the slope coefficient of the pad were able to improve load beating capability.
文摘In order to solve the hardening problem of complex calcium lubricating grease, the water absorption test of several calcium salts was carried out, and it was found that calcium 12-hydroxystearate did not absorb water, and calcium acetate, calcium phosphate and calcium borate had different degrees of water absorption. Calcium acetate has the highest water absorption rate, while calcium phosphate and calcium borate show comparable water absorption rates. Upon using the molecular simulation technology, it is found that in the complex calcium grease system, calcium phosphate and calcium borate tend to combine with water, which inhibits the water absorption of calcium acetate and alleviate the hardening problem.
基金supported by the National Natural Science Foundation of China (contract/grant number: 51274037) affiliated to the project: "The research of lubrication model and interaction between nano-lubricating particles and rolling deformed surface."
文摘A new kind of emulsion containing nano TiO_2 was developed through the dispersion experiment. A commercial emulsion and a prepared by our lab emulsion without nano particles were chosen as controls to test the tribological and antibacterial properties of this new emulsion. The load carrying capacity, friction coefficient and average diameter of wear scars were tested by a four-ball machine and the comprehensive antifriction parameter ω was calculated. The wetting angle was also tested using a JC200C1 wetting angle tester. The micro surface and roughness of rolled strips were analyzed to investigate the tribological performance of the recommended new emulsion in strip production. It is shown that the new nano-emulsion possesses a higher load carrying capacity and wetting ability. Therefore the abrasive/plowing wear is reduced more efficiently with the addition of nano particles, and the micro surface is improved. The density of bacteria in the emulsions was tested after the cold rolling experiment. The emulsion breaking ratio and bacteria density were also tested in different time intervals after the cold rolling experiment. The final p H values and bacteria density of different layers of emulsions were measured and the sediment was analyzed by TEM to evaluate the antibacterial behavior of this new emulsion. It is shown that the density of microbial colonies which led to a corruption of emulsions was decreased about 90% and the effective antibacterial period was prolonged.
基金financial support provided by the National Natural Science Foundation of China(Project No.51375491)the Natural Science Foundation of Chongqing(Project No.CSTC,2014JCYJAA50021)the Innovation Fund of Logistical Engineering University(Project No.YZ13-43703)
文摘Tribological properties of 150 SN mineral oil and the oils doped with different contents of zinc butyloctyldithiophosphate(T202) under magnetic field or non-magnetic field were evaluated on a four-ball tribotester by applying an external magnetic field around the friction region. Moreover, the morphology and the tribochemical characteristics of worn surfaces were examined by a scanning electron microscope(SEM) and an X-ray photoelectron spectrometer(XPS). Then the lubrication mechanisms were discussed. The tribological test results indicated that the wear scar diameters(WSDs) of steel balls lubricated by the T202-containing lubricating oils and the friction coefficients of the corresponding oil under magnetic field were smaller than those without magnetic affection. The worn surface lubricated with the T202-formulated oils in a magnetic field was smoother than that obtained under the normal condition. Furthermore, the results of XPS analysis indicated that tribochemical films on the surfaces lubricated with T202-doped oils were mainly composed of compounds such as FeSO_4, FeS and ZnS. The atomic concentrations of oxygen, sulfur, iron, zinc and phosphorus species identified in T202 under magnetic field were higher than those without magnetic impact. It can be inferred that the improved anti-wear and friction-reducing ability of T202-doped oils was attributed to the promoted tribochemical reactions and the modification of the worn surfaces induced by magnetic field.
文摘The factors affecting the developmcnt of Sinopec lubricating oil were analyzed in this paper, and an analytic hierarchy process （AHP） model for selecting lubricating-oil producing bases was developed. By using this model, nine lubricating oil producing companies under Sinopec were comprehensively evaluated. The evaluation result showed that the Maoming Lubricating Oil Company （Guangdong province）, Jingmen Lubricating Oil Company （Hubei province） and Changcheng Lube Oil Company （Beijing） are top three choices, and should be developed preferentially for the development of Sinopec producing bases of lubricating oil in the future. The conclusions provide the theoretical basis for selecting lubricating oil producing bases for decision makers.
