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Local Stress Analysis of Pipes with Ellipsoidal Defect at High Temperature

Wang Lili， Zhang Han, Qi Hanbing, Li Dong

Abstract （352）

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In order to study the local mechanical properties of pipeline's defects, taking X70 pipeline as the research object, based on the knowledge of elasticplastic mechanics, ANSYS is applied to simulate the distribution near defects of Von Mises stress and plastic strain under the action of high temperature. Then the variation tendency of the maximum stress and plastic strain of key parts near defects with the increase of internal pressure is analyzed. Also, the variation trend of the maximum Von Mises stress with the corrosion depth under the specific operating pressure is discussed. Finally, the Von Mises stress distribution and variation considering and without considering the temperature expansion are compared. The results show that there is a greater stress along the circumferential direction in the corrosion zone at high temperature. With the increase of internal pressure, the maximum Von Mises stress decreases first and then increases, and the greater stress also becomes axial distribution. ASME B31G1984,ASME B31G1991,PCORRC and DNVRPF101 methods are still suitable for evaluating the residual strength of pipelines under high temperature. 

2018, 31 (01): 95-100. DOI: :10.3969/j.issn.1006-396X.2018.01.095

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Simulation Analysis of the Gas Lift to Eliminate Severe Slugging

Li Dong, Wu Yuguo, Pan Zhen, Duan Tenglong

Abstract （704）

PDF （2607KB）（373）

In the exploitation of offshore oil and gas resources, the severe slugging will appear due to the special piping system, gravity, flow, and other factors. The severe slugging will cause secondary hazards and threaten the safety of production. Therefore, it is needed to adopt the method to eliminate the severe slugging. In this paper, OLGA software and PVTsim software were used to simulate the gaslift to eliminate the severe slugging. The results showed that the severe slugging could be eliminate by gaslift in a certain extent. Different gas injection position had different effect to eliminate severe slugging. When the position of gas injection was in the upstream at the bottom of the riser, severe slugging could be eliminated effectively.

2016, 29 (3): 87-91. DOI: 10.3969/j.issn.1006-396X.2016.03.017

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The Morphology Control Research of Paraffin/Melamine Resin Phase Transition Microcapsules

Qian Liuying, Li Dongxue, Li Fengyan, Wang Peng, Zhao Tianbo

Abstract （661）

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Microcapsules consisting of 58# paraffin wax used as the cores and melamineformaldehyde resin used as the shell were synthesized by the insitu polymerization, and the improvement of apparent morphology and core content of microcapsules was researched. The effects of pH adjustment method, the type of curing agent and stratified treatment on morphology and thermal storage property of microcapsule were studied by SEM, PSDA and DSC. It indicates that pH adjustment is an important factor to microcapsules' morphology and the overall property of microcapsules is greatly improved when NaCl is used as curing agent. After stratified processing, particle sizes of the microcapsules show unimodal distribution and core material content is up to 86.1%.

2016, 29 (3): 7-11. DOI: 10.3969/j.issn.1006-396X.2016.03.002

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Synthesis of 2Methylidenebutanedioyl Dichloride

Wang Chuanxing, Li Dongyang, Liu Junkai, et al

Abstract （433）

PDF （1956KB）（345）

2methylidenebutanedioyl dichloride(Itaconyl chloride) was synthesized using itaconic acid and phosphorus pentachloride as raw materials by melting method. The effect of raw material ratio, reaction time, temperature and other process conditions on yield of product was examined. The structure of the product was characterized by IR and 1HNMR .The experiments showed that, when the itaconyl chloride and phosphorus pentachloride molar ratio was 1∶2.2, reaction temperature was 110 ℃ and reaction time was 2 h, the yield of 2methylidenebutanedioyl dichloride can reach 86% and its purity was more than 94%.

2014, 27 (6): 7-10. DOI: 10.3969/j.issn.1006-396X.2014.06.002

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Preparation and Characterization of CaO/ZnAlO Solid Base and Its Catalytic Activity

Jin Fuquan， Li Xiaohong， Li Donghong

Abstract （420）

PDF （2537KB）（282）

CaO/ZnAlO solid base catalyst was prepared using coprecipitation, impregnation and calcination method. Effects of preparation conditions on the catalytic activity of CaO/ZnAlO solid base in oil alcoholysis were investigated through orthogonal experiments. Optimized conditions obtained were as follows: the first calcination time of 0 h, the second calcination temperature of 750 ℃, the second calcination time of 3 h. When the reaction was carried out at 70 ℃ for 4 h with alcohol/oil molar ratio of 9,catalyst/oil mass ratio of 004, stirring speed of 400 r/min, rapeseed oil conversion arrived at 96.3% in the presence of the CaO/ZnAlO catalyst prepared at optimal conditions. The catalyst and its precursor were characterized using TGDTA, BET, XRD, SEM and Hammett indicator method. Relationship between the structure and the surface properties of the catalyst and its activity was discussed. 

2014, 27 (5): 43-49. DOI: 10.3969/j.issn.1006-396X.2014.05.010

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Furfural Refining on Second Vacuum Dewaxed Distillate

Long Wenyu, Li Dongsheng, Li Xiaoou,et al

Abstract （449）

PDF （1822KB）（351）

Solvent refining on the second vacuum dewaxed distillate refined from the mixed oil of Daqing and Weizhou using furfural was investigated. Calibration on theoretical plate number in the extraction column, multistage static extraction and pilot plant experiment were carried out in turns. The results show that theoretical plate number in the column is two. Viscosity index of refined oil is 100 under both simulatetwostage extractions when the value of volume ratio of solvent to oil (S/O) was 5.47∶1 and simulatefourstage extractions when the S/O was 3.2∶1, and the yield of refined oil is 64.07% and 66.01% respectively. Besides, viscosity index of the refined oil is 101 in the pilot plant with four theoretical plates when the S/O was 327∶1, and the yield of refined oil is 70.5%. The lubricating base oil meets the quality specification of HVI150SN.

2014, 27 (2): 32-36. DOI: 10.3969/j.issn.1006-396X.2014.02.007

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NMP Refining VGO No.5 From Daqing and Shenbei by Simulate Continuous Refining

LI Xiao-ou, XU Ying,LI Dong-sheng,et al

Abstract （648）

PDF （181KB）（337）

Solvent refining of VGO No.5 using N-methyl-2-pyrrolidone(NMP) and furfural separately were studied. Based on the optimum operation conditions of NMP and furfural refining, simulating three stages about NMP and furfural extracting VGO No.5 and dewaxing the refined oil were carried out. The properties of refined oil and dewaxed oil were analyzed. The qualities of refined oil from single stage refining using NMP and furfural were closed to. The dewaxed oil of two can satisfy the indication of quality. For NMP refining, compared with furfural refining, the solvent to oil ratio dropped down 50% and the yield increased 7%. For simulating three stages refining using NMP, as compared to furfural, the solvent to oil ratio dropped down 50% and the yield increased 4%. The qualities of refined oils are closed to and better than these of single stage refining oils. The study show that NMP refining had a better result than furfural refining.

2012, 25 (2): 8-11. DOI: 10.3969/j.issn.1006-396X.2012.02.003

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Comparative on NMP and Furfural Solvent Refining of High-Viscosity Lubricating Oil on Laboratory Scale

LI Dong-sheng,HUANG Liang,WANG Lei,et al

Abstract （807）

PDF （280KB）（492）

Single stage refining and simulating three stages refining with furfural and N-methyl-2- pyrrolidone were carried out using vacuum gas oil (VGO) blended with Daqing and Shenbei oil as raw material.The optimum operation conditions were determined under the requirement about HVI500SN,and the experimental results were analyzed contrastively.The results show that when NMP refining is compared with furfural refining under the circumstance of the same refining effect,the refining temperature is decreased by 20℃,the mass ratio of solvent to oil is decreased by 40%,and the yield of refined oil is increased by 3% ,which show NMP refining is superior to furfural refining.

2011, 24 (4): 47-50. DOI: 10.3696/j.issn.1006-396X.2011.04.013

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Complex Denitrification in Lubricant by Joining Furfural and Additives

LI Dong-sheng,ZHANG Jian-shu,LI Xiao-ou,ZHAI Yu-chun

Abstract （527）

PDF （199KB）（457）

The study of complex de-nitride in lubricant by furfural and additives was researched for a second-tier base oil in Fushun No.1oil plant, according to single factor experiments, influences on removal rate of the basic nitrogen by temperature and oil/solvent ratio were obtained, finding a more suitable metal additive dosage of 0.50~1.33(mol zinc bromide/mol quinoline).Then through orthogonal test determining the effects on the complex extraction(removal rate of basic nitrogen), the most influential factor is the metal additive dosage, followed by the oil/solvent ratio, temperature minimum. The results show that adding a small amount of zinc bromide can greatly enhance the effect of furfural refining, its basic nitrogen removal rate increases, it greatly increases the effect of furfural extraction.

2011, 24 (3): 43-46. DOI: 10.3696/j.issn.1006-396X.2011.03.011

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Pretreatment of Coking Gas Oil in Dagang Tianjin

ZHAO Bo,LI Dong-sheng,DAI Yue-ling,et al

Abstract （640）

PDF （250KB）（473）

In order to study the content of alkaline nitrogen compounds and the oil yield, using complexion to pretreatment of coking gas oil. There were many affecting factors on alkaline nitrogen compounds remove rate and the light oil yield, such as reaction time, reaction temperature, solvent to oil mass ratio and so on. The best experimental condition is defined by regular-crossed trial. The results show that the oil yield is 94.92% [KG*4]and [KG*4]the [KG*4]separation [KG*4]rate [KG*4]of [KG*4]alkaline [KG*4]nitrogen [KG*4]compounds [KG*4]is 85.42% at condition of reaction temperature 59 ℃, solvent to oil mass ratio 0.021, stirring speed 300 r/min, reaction time 15 minutes and settling time 15 minutes.

2011, 24 (2): 69-72. DOI: 10.3696/j.issn.1006-396X.2011.02.018

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Laboratorg Trail Study on NMP Refining of High-Viscosity VGO

LI Xiao-ou,ZHANG De-ning,LI Dong-sheng

Abstract （601）

PDF （254KB）（417）

Single stage refining of high-viscosity lubricating oil using N-methyl-2-pyrrolidone (NMP) was carried out. The suitable operating conditions of the NMP refining were determined by orthogonal test and mathematical ways. On this basis, a simulate-three-stage extraction and dewaxing tests of NMP were done. The results show that the operation conditions of NMP anhydrous extraction are [KG*4]as follows: extracting [KG*4]temperature 87 ℃, the [KG*4]volume [KG*4]ratio [KG*4]of [KG*4]solvent to oil is 0.75. Under same conditions, NMP anhydrous single-stage extraction are as follows: the yield of refined oil is 90.1%, the refractive index is 1.464 5 at 60 ℃. NMP anhydrous simulate-three-stage extraction are as follows: the yield of refined oil is 90%, the refractive index is 1.462 2 at 60 ℃. Volume fraction of water 1.5% of extraction suitable operating conditions are as follows: extracting temperature 88.5 ℃, the volume ratio of solvent to oil is 1.38.Under same conditions, NMP single-stage extraction are as follows: the yield of refined oil is 87.7%, the refractive index is 1.463 1;NMP simulate-three-stage extraction are as follows: the yield of refined oil is 87%, the refractive index is 1.461 0 at 60 ℃. From refractive index changes to know that the effect of simulate-three-stage test is better than single-stage extraction test.

2011, 24 (2): 54-57. DOI: 10.3696/j.issn.1006-396X.2011.02.014

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Furfural Process Denitrogenating of Lube Base Oil Into Which the Assistants is Added

LI DONG-sheng,ZHANG Yi,SONG Yi,ZHAI Yu-chun

Abstract （718）

PDF （248KB）（493）

In order to improve the oxidation stability of lube oil, the denitrogeneration refining laboratory scale test and pilotscale experiment had been done systematically for the second and third vacuum side dewaxed oil of No.1 refinery with the method of complex extraction. The results show that the mixed solvent of furfural and metallic salt can remove the basic nitrogen compounds in dewaxed oil effectively, the basic nitrogen compounds constituents in dewaxed oil were decreased from 432.32 μg/g to 91.99 μg/g,the denitrification percent was 78.12%. A fitting operation condition that the No.1 refinerys third vacuum side dewaxed oil was well extracted with furfural in laboratory was quantity of additive 6 g/kg,refining temperature 118 ℃,refining time 20 min, solvent to oil volume ratio 2.0,settling time 30 min.While a fitting operation condition that the refining oil was well extracted with atlapulgite quantity of atlapulgite 2.5%, refining temperature 150 ℃, refining time 20 min,atlapulgite wasnt torfiyed.

2011, 24 (1): 41-43. DOI: 10.3696/j.issn.1006-396X.2011.01.010

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Research on Profile Control and Water Shut-off Performance of Pre-Crosslinked Gel Particles and Matching Relationship Between Particle and Pore Size

LI Dong-xu, HOU Ji-rui, ZHAO Feng-lan, et al

Abstract （660）

PDF （791KB）（524）

Experiments on injectivity and profile control performance of pre-crosslinked gel particles widely used in oilfields were done. The results show that the injectivity of pre-crosslinked gel particle is poor. Most of particles pile up in the front of sand pack, and the migration distance of pre-crosslinked gel particles is less than 20 cm, which lead to the formation of filter cake and the poor effects of depth profile control. The injection of pre-crosslinked gel particle is selectivity. In the early stage of profile control, the diversion rate of low permeability layer increases slightly, and the effect is less than 2%. After long-term waterflooding, due to the easily breakthrough in higher permeability layers, the diversion rate of low permeability layer declines in comparison that before the operation. It is indicated that pre-crosslinked gel particles will harm low permeability layers. It is calculated and analyzed that the diameters of current pre-crosslinked gel particles are bigger than pore size. Theoretically, current pre-crosslinked gel particles are difficult to be applied in depth profile control.

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2010, 23 (2): 25-28.

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Global Stability in a n-Species System With Time Delay

LI Shi－tao, LI Dong－mei

Abstract （290）

PDF （1065KB）（194）

One of the most interesting topics in ecology systems is the stability of species. It is a n-species (one-prey, the others-predator) ratio-dependent predator-prey system with time delay and functional response at the seme time and was studied. By differential inequality constructing suitable Lyapunov functional, a sufficient condition was obtained for the global stability of the positive equilibrium of the system. Finally, the numerical simulation result of population model was given.

2007, 20 (2): 84-87.