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Numerical Simulation Analysis of the Transformer Fire Extinguishing Process with a High-Pressure Water Mist System under Different Conditions 被引量:1
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作者 Haowei Yao Youxin Li +7 位作者 Kefeng Lv Dong Wang Jinguang Zhang Zhenyu Zhan Zhenyu Wang Huaitao Song Xiaoge Wei Hengjie Qin 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第7期733-747,共15页
To thoroughly study the extinguishing effect of a high-pressure water mist fire extinguishing system when a transformer fire occurs,a 3D experimental model of a transformer is established in this work by employing Fir... To thoroughly study the extinguishing effect of a high-pressure water mist fire extinguishing system when a transformer fire occurs,a 3D experimental model of a transformer is established in this work by employing Fire Dynamics Simulator(FDS)software.More specifically,by setting different parameters,the process of the highpressure water mist fire extinguishing system with the presence of both diverse ambient temperatures and water mist sprinkler laying conditions is simulated.In addition,the fire extinguishing effect of the employed high-pressure water mist system with the implementation of different strategies is systematically analyzed.The extracted results show that a fire source farther away fromthe centerline leads to a lower local temperature distribution.In addition,as the ambient temperature increases,the temperature above the fire source decreases,while the temperature and the concentrationof theupperflue gas layer bothdecrease.Interestingly,after thehigh-pressurewatermist sprinkler begins to operate,both the temperature distribution above the fire source and the concentration of the flue gas decrease,which indicates that the high-pressure water mist system plays the role of cooling and dust removal.By comparing various sprinkler laying methods,it is found that the lower sprinkler height has a better effect on the temperature above the fire source,the temperature of the upper flue gas layer,and the concentration of the flue gas.Moreover,when the sprinkler is spread over thewhole transformer,the cooling effect on both the temperature above the fire source and the temperature of the upper flue gas layer is good,whereas the change in the concentration of the flue gas above the fire source is not obvious compared to the case where the sprinkler is not fully spread. 展开更多
关键词 Transformer fire high-pressure water mist TEMPERATURE flue gas concentration
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Gas Film Disturbance Characteristics Analysis of High-Speed and High-Pressure Dry Gas Seal 被引量:13
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作者 CHEN Yuan JIANG Jinbo PENG Xudong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第6期1226-1233,共8页
The dry gas seal(DGS) has been widely used in high parameters centrifugal compressor, but the intense vibrations of shafting, especially in high-speed condition, usually result in DGS's failure. So the DGS's abili... The dry gas seal(DGS) has been widely used in high parameters centrifugal compressor, but the intense vibrations of shafting, especially in high-speed condition, usually result in DGS's failure. So the DGS's ability of resisting outside interference has become a determining factor of the further development of centrifugal compressor. However, the systematic researches of which about gas film disturbance characteristics of high parameters DGS are very little. In order to study gas film disturbance characteristics of high-speed and high-pressure spiral groove dry gas seal(S-DGS) with a flexibly mounted stator, rotor axial runout and misalignment are taken into consideration, and the finite difference method and analytical method are used to analyze the influence of gas film thickness disturbance on sealing performance parameters, what's more, the effects of many key factors on gas film thickness disturbance are systematically investigated. The results show that, when sealed pressure is 10.1MPa and seal face average linear velocity is 107.3 m/s, gas film thickness disturbance has a significant effect on leakage rate, but has relatively litter effect on open force; Excessively large excitation amplitude or excessively high excitation frequency can lead to severe gas film thickness disturbance; And it is beneficial to assure a smaller gas film thickness disturbance when the stator material density is between 3.1 g/cm3 to 8.4 g/cm3; Ensuring sealing performance while minimizing support axial stiffness and support axial damping can help to improve dynamic tracking property of dry gas seal. The proposed research provides the instruction to optimize dynamic tracking property of the DGS. 展开更多
关键词 high-speed and high-pressure dry gas seal gas film thickness disturbance dynamic tracking property
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A study of hydrate plug formation in a subsea natural gas pipeline using a novel high-pressure flow loop 被引量:12
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作者 Li Wenqing Gong Jing +3 位作者 Lü Xiaofang Zhao Jiankui Feng Yaorong Yu Da 《Petroleum Science》 SCIE CAS CSCD 2013年第1期97-105,共9页
The natural gas pipeline from Platform QKI8-1 in the southwest of Bohai Bay to the onshore processing facility is a subsea wet gas pipeline exposed to high pressure and low temperature for a long distance. Blockages i... The natural gas pipeline from Platform QKI8-1 in the southwest of Bohai Bay to the onshore processing facility is a subsea wet gas pipeline exposed to high pressure and low temperature for a long distance. Blockages in the pipeline occur occasionally. To maintain the natural gas flow in the pipeline, we proposed a method for analyzing blockages and ascribed them to the hydrate formation and agglomeration. A new high-pressure flow loop was developed to investigate hydrate plug formation and hydrate particle size, using a mixture of diesel oil, water, and natural gas as experimental fluids. The influences of pressure and initial flow rate were also studied. Experimental results indicated that when the flow rate was below 850 kg/h, gas hydrates would form and then plug the pipeline, even at a low water content (10%) of a water/oil emulsion. Furthermore, some practical suggestions were made for daily management of the subsea pipeline. 展开更多
关键词 Natural gas hydrate BLOCKAGE flow assurance high-pressure loop water cut flow rate
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Simulation on flow, heat transfer and stress characteristics of large-diameter thick-walled gas cylinders in quenching process under different water spray volumes 被引量:2
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作者 GAO Jing-na GAO Ying +2 位作者 XU Qin-ran WANG Ge LI Qiang 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第11期3188-3199,共12页
Cooling strength is one of the important factors affecting microstructure and properties of gas cylinders during quenching process,and reasonable water spray volume can effectively improve the quality of gas cylinders... Cooling strength is one of the important factors affecting microstructure and properties of gas cylinders during quenching process,and reasonable water spray volume can effectively improve the quality of gas cylinders and reduce production costs.To find the optimal water spray parameters,a fluid-solid coupling model with three-phase flow was established in consideration of water-vapor conversion.The inner and outer walls of gas cylinder with the dimensions of d914 mm×38 mm×12000 mm were quenched using multi-nozzle water spray system.The internal pressure,average heat transfer coefficient(have)and stress of the gas cylinder under different water spray volumes during quenching process were studied.Finally,the mathematical model was experimentally verified.The results show that both the internal pressure and have increase along with the increase of spray volume.The internal pressure increases slowly first and then rapidly,but have increases rapidly first and then slowly.To satisfy hardenability of gas cylinders,the minimum spray volume should not be less than 40 m^3/(h·m).The results of stress indicate that water spray quenching will not cause deformation of bottle body in the range of water volume from 40 to 290 m^3/(h·m). 展开更多
关键词 large-diameter thick-walled gas cylinders QUENCHING water spray volume heat transfer STRESS numerical simulation
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Safety estimation of high-pressure hydraulic cylinder using FSI method 被引量:1
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作者 KIM J.H. HAN S.M. KIM Y.J. 《排灌机械工程学报》 EI CSCD 北大核心 2016年第5期418-423,共6页
Hydraulic cylinder is a primary component of the hydraulic valve systems.The numerical study of hydraulic cylinder to evaluate the stress analysis,the life assessment and the performance of operation characteristics i... Hydraulic cylinder is a primary component of the hydraulic valve systems.The numerical study of hydraulic cylinder to evaluate the stress analysis,the life assessment and the performance of operation characteristics in hydraulic cylinder were described.The calculation of safety factor,fatigue life,piston chamber pressure,rod chamber pressure and the change of velocity of piston with flow time after the beginning of hydraulic cylinder were incorporated.Numerical analysis was performed using the commercial CFD code,ANSYS with unsteady,dynamic mesh model,two-way FSI(fluid-structure interaction)method and k-εturbulent model.The internal pressure in hydraulic cylinder through stress analysis show higher than those of the yield strength. 展开更多
关键词 two-way fluid-structure interaction high-pressure hydraulic cylinder durability life safety estimation dynamic mesh
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Mold Filling and Prevention of Gas Entrapment in High-pressure Die-casting 被引量:1
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作者 Itsuo Ohnaka Akira Sugiyama +1 位作者 Takashi Ikeda Hideyuki Yasuda 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2008年第1期139-140,共2页
This paper presents some results of direct observation of mold filling in a specially designed die-casting by X-ray diffraction, including comparison with numerical simulation. Based on such work the authors discuss h... This paper presents some results of direct observation of mold filling in a specially designed die-casting by X-ray diffraction, including comparison with numerical simulation. Based on such work the authors discuss how to prevent gas entrapment and propose new methods. 展开更多
关键词 Direct observation Mold filling high-pressure die-casting Computer simulation gas entrapment
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Research on thermal insulation materials properties under HTHP conditions for deep oil and gas reservoir rock ITP-Coring 被引量:1
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作者 Zhi-Qiang He He-Ping Xie +4 位作者 Ling Chen Jian-Ping Yang Bo Yu Zi-Jie Wei Ming-Zhong Gao 《Petroleum Science》 SCIE EI CAS CSCD 2024年第4期2625-2637,共13页
Deep oil and gas reservoirs are under high-temperature conditions,but traditional coring methods do not consider temperature-preserved measures and ignore the influence of temperature on rock porosity and permeability... Deep oil and gas reservoirs are under high-temperature conditions,but traditional coring methods do not consider temperature-preserved measures and ignore the influence of temperature on rock porosity and permeability,resulting in distorted resource assessments.The development of in situ temperaturepreserved coring(ITP-Coring)technology for deep reservoir rock is urgent,and thermal insulation materials are key.Therefore,hollow glass microsphere/epoxy resin thermal insulation materials(HGM/EP materials)were proposed as thermal insulation materials.The materials properties under coupled hightemperature and high-pressure(HTHP)conditions were tested.The results indicated that high pressures led to HGM destruction and that the materials water absorption significantly increased;additionally,increasing temperature accelerated the process.High temperatures directly caused the thermal conductivity of the materials to increase;additionally,the thermal conduction and convection of water caused by high pressures led to an exponential increase in the thermal conductivity.High temperatures weakened the matrix,and high pressures destroyed the HGM,which resulted in a decrease in the tensile mechanical properties of the materials.The materials entered the high elastic state at 150℃,and the mechanical properties were weakened more obviously,while the pressure led to a significant effect when the water absorption was above 10%.Meanwhile,the tensile strength/strain were 13.62 MPa/1.3%and 6.09 MPa/0.86%at 100℃ and 100 MPa,respectively,which meet the application requirements of the self-designed coring device.Finally,K46-f40 and K46-f50 HGM/EP materials were proven to be suitable for ITP-Coring under coupled conditions below 100℃ and 100 MPa.To further improve the materials properties,the interface layer and EP matrix should be optimized.The results can provide references for the optimization and engineering application of materials and thus technical support for deep oil and gas resource development. 展开更多
关键词 Deep oil and gas reservoir rock In situ temperature-preserved coring(ITPCoring) Hollow glass microsphere/epoxy resin thermal insulation materials(HGM/EP materials) High-temperature and high-pressure(HTHP) Physical and mechanical properties
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Investigations of methane adsorption characteristics on marine-continental transitional shales and gas storage capacity models considering pore evolution
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作者 Chen-Gang Lu Xian-Ming Xiao +4 位作者 Zhen-Qian Xue Zhang-Xin Chen Yin-Tao Dong Yue Feng Gang Li 《Petroleum Science》 SCIE EI CAS CSCD 2024年第4期2273-2286,共14页
Methane adsorption is a critical assessment of the gas storage capacity(GSC)of shales with geological conditions.Although the related research of marine shales has been well-illustrated,the methane adsorption of marin... Methane adsorption is a critical assessment of the gas storage capacity(GSC)of shales with geological conditions.Although the related research of marine shales has been well-illustrated,the methane adsorption of marine-continental transitional(MCT)shales is still ambiguous.In this study,a method of combining experimental data with analytical models was used to investigate the methane adsorption characteristics and GSC of MCT shales collected from the Qinshui Basin,China.The Ono-Kondo model was used to fit the adsorption data to obtain the adsorption parameters.Subsequently,the geological model of GSC based on pore evolution was constructed using a representative shale sample with a total organic carbon(TOC)content of 1.71%,and the effects of reservoir pressure coefficient and water saturation on GSC were explored.In experimental results,compared to the composition of the MCT shale,the pore structure dominates the methane adsorption,and meanwhile,the maturity mainly governs the pore structure.Besides,maturity in the middle-eastern region of the Qinshui Basin shows a strong positive correlation with burial depth.The two parameters,micropore pore volume and non-micropore surface area,induce a good fit for the adsorption capacity data of the shale.In simulation results,the depth,pressure coefficient,and water saturation of the shale all affect the GSC.It demonstrates a promising shale gas potential of the MCT shale in a deeper block,especially with low water saturation.Specifically,the economic feasibility of shale gas could be a major consideration for the shale with a depth of<800 m and/or water saturation>60%in the Yushe-Wuxiang area.This study provides a valuable reference for the reservoir evaluation and favorable block search of MCT shale gas. 展开更多
关键词 high-pressure methane adsorption Marine-continental transitional shale gas Ono-Kondo model Adsorption thermodynamics gas storage capacity model
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Productivity Analysis Method of Abnormal High-Pressure Gas Reservoir in Ying-Qiong Basin
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作者 Qi Zhu Hao Liang 《Natural Resources》 2017年第6期410-415,共6页
Ying-Qiong Basin in the west of South China Sea contains plenty of abnormal high-pressure gas reservoirs, whose stress sensitivity is crucial for well productivity. To explore the influence of stress sensitivity on pr... Ying-Qiong Basin in the west of South China Sea contains plenty of abnormal high-pressure gas reservoirs, whose stress sensitivity is crucial for well productivity. To explore the influence of stress sensitivity on production, the variable outlet back pressure stress sensitivity experiments were applied to test core sample permeability under different burden pressure and obtain the relational expression of power function of core stress sensitivity. Afterwards, new productivity equation is deduced in consideration of reservoir stress sensitivity, and the affection of stress sensitivity on production is analyzed. The result demonstrates close link between stress sensitivity and productivity, since single well production decreases dramatically when reservoir stress sensitivity has been taken into account. This research is constructive for well-testing data interpretation in stress sensitive gas reservoirs. 展开更多
关键词 Ying-Qiong BASIN ABNORMAL high-pressure gas RESERVOIR STRESS Sensitivity PRODUCTIVITY Analysis
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Numerical simulation and experimental verification of a novel double-layered split die for high-pressure apparatus used for synthesizing superhard materials 被引量:1
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作者 Zhuo Yi Wen-zhi Fu +3 位作者 Ming-zhe Li Rui Li Liang Zhao Li-yan Wang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2019年第3期377-385,共9页
Based on the principles of massive support and lateral support, a novel double-layered split die(DLSD) for high-pressure apparatus was designed to achieve a higher pressure-bearing capacity and larger sample cavity. T... Based on the principles of massive support and lateral support, a novel double-layered split die(DLSD) for high-pressure apparatus was designed to achieve a higher pressure-bearing capacity and larger sample cavity. The stress distributions of the DLSDs with different numbers of divided blocks were investigated by the finite element method and compared with the stress distributions of the conventional belt-type die(BTD). The results show that the cylinders and first-layer supporting rings of the DLSDs have dramatically smaller stresses than those of the BTD. In addition, increasing the number of divided blocks from 4 to 10 gradually increases the stress of the cylinder but has minimal influence on the stress of the supporting rings. The pressure-bearing capacities of the DLSDs with different numbers of divided blocks, especially with fewer blocks, are all remarkably higher than the pressure-bearing capacity of the BTD. The contrast experiments were also carried out to verify the simulated results. It is concluded that the pressure-bearing capacities of the DLSDs with 4 and 8 divided blocks are 1.58 and 1.45 times greater than that of the BTD. This work is rewarding for the commercial synthesis of high-quality, large-sized superhard materials using a double-layered split high-pressure die. 展开更多
关键词 SPLIT DIE prismatic cylindER pressure-bearing capacity high-pressure apparatus SUPERHARD material FEM
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Dynamic effects of high-pressure pulsed water jet in low-permeability coal seams 被引量:1
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作者 LI Xiao-hong ZHOU Dong-ping LU Yi-yu KANG Yong ZHAO Yu WANG Xiao-chuan 《Journal of Coal Science & Engineering(China)》 2009年第3期284-288,共5页
Mine gas extraction in China is difficult due to the characteristics such as micro-porosity,low-permeability and high adsorption of coal seams.The pulsed mechanismof a high-pressure pulsed water jet was studied throug... Mine gas extraction in China is difficult due to the characteristics such as micro-porosity,low-permeability and high adsorption of coal seams.The pulsed mechanismof a high-pressure pulsed water jet was studied through theoretical analysis,experimentand field measurement.The results show that high-pressure pulsed water jet has threedynamic properties.What's more,the three dynamic effects can be found in low-permeabilitycoal seams.A new pulsed water jet with 200-1 000 Hz oscillation frequency andpeak pressure 2.5 times than average pressure was introduced.During bubble collapsing,sound vibration and instantaneous high pressures over 100 MPa enhanced the cuttingability of the high-pressure jet.Through high-pressure pulsed water jet drilling and slotting,the exposure area of coal bodies was greatly enlarged and pressure of the coal seamsrapidly decreased.Therefore,the permeability of coal seams was improved and gas absorptionrate also decreased.Application results show that gas adsorption rate decreasedby 30%-40%and the penetrability coefficient increased 100 times.This proves that high-pressurepulsed water is more efficient than other conventional methods. 展开更多
关键词 high-pressure pulsed water jet gas desorption penetrability dynamic effects
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Formation of Large-Volume High-Pressure Plasma in Triode-Configuration Discharge Devices
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作者 江超 王又青 《Plasma Science and Technology》 SCIE EI CAS CSCD 2006年第2期185-189,共5页
A "plane cathode micro-hollow anode discharge (PCHAD)" is studied in comparison with micro-hollow cathode discharge (MHCD). A new triode-configuration discharge device is also designed for large-volume, high-pre... A "plane cathode micro-hollow anode discharge (PCHAD)" is studied in comparison with micro-hollow cathode discharge (MHCD). A new triode-configuration discharge device is also designed for large-volume, high-pressure glow discharges plasma without glow-to-arc transitions, as well as with an anode metal needle, and a cathode of PCHAD. It has a "needle-hole" sustained glow discharge. Its discharge circuit employs only one power supply circuit with a variable resistor. The discharge experiments have been carried out in the air. The electrical properties and the photoimages in PCHAD, multi-PCHAD and "needle-hole" sustained discharge have been investigated. The electrical and the optical measurements show that this triode-configuration discharge device can operate stably at high-pressure, in parallel without individual ballasting resistance. And the electron density of the plasma is estimated to be up to 10^12cm^-3. Compared with the twosupply circuit system, this electrode configuration is very simple with lower cost in generating large-volume plasma at high pressures. 展开更多
关键词 gas discharge high-pressure plasma plane-cathode current-voltage characteristic
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AN ADVANCED TECHNOLOGY OF DRAWING IN GAS-STORAGE CYLINDER MAKING
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作者 Guo Baofeng, Ren Yunlai, Li Weimin, Gao Shiyou, Gu Yuji and Su ShenguiYanshan University, Qinhuangdao 066004, P. R. China 《中国有色金属学会会刊:英文版》 CSCD 1998年第2期46-50,共5页
ANADVANCEDTECHNOLOGYOFDRAWINGINGASSTORAGECYLINDERMAKING①GuoBaofeng,RenYunlai,LiWeimin,GaoShiyou,GuYujiandSu... ANADVANCEDTECHNOLOGYOFDRAWINGINGASSTORAGECYLINDERMAKING①GuoBaofeng,RenYunlai,LiWeimin,GaoShiyou,GuYujiandSuShenguiYanshanUni... 展开更多
关键词 FORGING gasstorage cylindER DRAWING hydropress 2way cartridge VALVE
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Heavy Duty Natural Gas Single Cylinder Research Engine Installation, Commissioning, and Baseline Testing
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作者 Juan Felipe Rodriguez Hui Xu +3 位作者 Greg Hampson Bret Windom Anthony Marchese Daniel B. Olsen 《Energy and Power Engineering》 2022年第6期217-232,共16页
Natural Gas (NG) Internal Combustion Engines (ICE) are a promising alternative to diesel engines for on-road heavy-duty applications to reduce greenhouse gas and harmful pollutant emissions. NG engines have not been w... Natural Gas (NG) Internal Combustion Engines (ICE) are a promising alternative to diesel engines for on-road heavy-duty applications to reduce greenhouse gas and harmful pollutant emissions. NG engines have not been widely adopted due to the lower thermal efficiency compared with diesel engine counterparts. To develop the base knowledge required to reach the desired efficiency, a Single Cylinder Engine (SCE) is the most effective platform to acquire reliable and repeatable data. A SCE test cell was developed using a Cummins 15-liter six-cylinder heavy-duty engine block modified to fire one cylinder (2.5-liter displacement). A Woodward Large Engine Control Module (LECM) is integrated to permit implementation of real-time advanced combustion control. Intake and exhaust characteristics, fuel composition, and exhaust gas recirculated substitution rate (EGR) are fully adjustable. A high-speed data acquisition system acquires in-cylinder, intake, and exhaust pressure for combustion analysis. The baseline testing shows reliable and consistent results for engine thermal efficiency, indicated mean effective pressure (IMEP), and coefficient of variance of the IMEP over a wide range of operating conditions while achieving effective control of all engine control and operation variables. This test cell will be used to conduct a research program to develop new and innovative control algorithms and CFD optimized combustion chamber designs, allowing ultra-high efficiency and low emissions for NG ICE heavy-duty on-road applications. 展开更多
关键词 Single cylinder Engine Heat Release Heavy Duty Natural gas End gas Auto-Ignition
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Natural gas density under extremely high pressure and high temperature: Comparison of molecular dynamics simulation with corresponding state model 被引量:1
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作者 Luchao Jin Yongming He +3 位作者 Guobing Zhou Qiuhao Chang Liangliang Huang Xingru Wu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第3期2-9,共8页
This work applied molecular dynamics(MD)simulation to calculate densities of natural gas mixtures at extremely high pressure(>138 MPa)and high temperature(>200℃)conditions(x HPHT)to bridge the knowledge and tec... This work applied molecular dynamics(MD)simulation to calculate densities of natural gas mixtures at extremely high pressure(>138 MPa)and high temperature(>200℃)conditions(x HPHT)to bridge the knowledge and technical gaps between experiments and classical theories.The experimental data are scarce at these conditions which are also out of assumptions for classical predictive correlations,such as the Dranchuk&Abou-Kassem(DAK)equation of state(EOS).Force fields of natural gas components were carefully chosen from literatures and the simulation results are validated with experimental data.The largest relative error is 2.67%for pure hydrocarbons,2.99%for C1/C3 mixture,7.85%for C1/C4 mixture,and 8.47%for pure H2S.These satisfactory predictions demonstrate that the MD simulation approach is reliable to predict natural-and acid-gases thermodynamic properties.The validated model is further used to generate data for the study of the EOS with pressure up to 276 MPa and temperature up to 573 K.Our results also reveal that the Dranchuk&Abou-Kassem(DAK)EOS is capable of predicting natural gas compressibility to a satisfactory accuracy at x HPHT conditions,which extends the confidence range of the DAK EOS. 展开更多
关键词 high-pressure high temperature Z-factor Molecular dynamics simulation Natural gas density CORRELATIONS
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Development of a simplified n-heptane/methane model for high-pressure direct-injection natural gas marine engines 被引量:3
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作者 Jingrui LI Haifeng LIU +5 位作者 Xinlei LIU Ying YE Hu WANG Xinyan WANG Hua ZHAO Mingfa YAO 《Frontiers in Energy》 SCIE CSCD 2021年第2期405-420,共16页
High-pressure direct-injection (HPDI) of natu- ral gas is one of the most promising solutions for future ship engines, in which the combustion process is mainly controlled by the chemical kinetics. However, the employ... High-pressure direct-injection (HPDI) of natu- ral gas is one of the most promising solutions for future ship engines, in which the combustion process is mainly controlled by the chemical kinetics. However, the employment of detailed chemical models for the multi-dimensional combustion simulation is significantly expensive due to the large scale of the marine engine. In the present paper, a reduced n-heptane/methane model consisting of 35-step reactions was constructed using multiple reduction approaches. Then this model was further reduced to include only 27 reactions by utilizing the HyChem (Hybrid Chemistry) method. An overall good agreement with the experimentally measured ignition delay data of both n-heptane and methane for these two reduced models was achieved and reasonable predictions for the measured laminar flame speeds were obtained for the 35-step model. But the 27-step model cannot predict the laminar flame speed very well. In addition, these two reduced models were both able to reproduce the experimentally measured in-cylinder pressure and heat release rate profiles for a HPDI natural gas marine engine, the highest error of predicted combustion phase being 6.5%. However, the engine-out CO emission was over-predicted and the highest error of predicted NOx emission was less than 12.9%. The predicted distributions of temperature and equivalence ratio by the 35-step and 27-step models are similar to those of the 334-step model. However, the predicted distributions of OH and CH2O are significantly different from those of the 334-step model. In short, the reduced chemical kinetic models developed provide a high-efficient and dependable method to simulate the characteristics of combustion and emissions in HPDI natural gas marine engines. 展开更多
关键词 high-pressure direct-injection natural gas chemical kinetics combustion modelling marine engine
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Fatigue Analysis of Liquefied Petroleum Gas Cylinders for Safety Risk Assessment
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作者 ZHOU Feng LIU Haotian LA Jiankai 《Journal of Shanghai Jiaotong university(Science)》 EI 2020年第3期394-397,共4页
With the widespread application of liquefied petroleum gas (LPG),the safety of LPG cylinder has received more and more attention.For the safety of LPG cylinder,we conduct a safety risk assessment of cylinder using the... With the widespread application of liquefied petroleum gas (LPG),the safety of LPG cylinder has received more and more attention.For the safety of LPG cylinder,we conduct a safety risk assessment of cylinder using the failure mode and effect analysis (FMEA) method.Taking the most influential inflatable fatigue under normal conditions as the research object,we use FE-safe software to analyze the fatigue failure.The risk compliance coefficients of various failure modes are calculated and classified according to the risk level.In this way,the service life of the LPG cylinder weld is determined.The presented method improves the safety risk assessment process of LPG cylinder and provides a good theoretical and practical basis for similar pressure vessel risk assessment. 展开更多
关键词 liquefied petroleum gas(LPG)cylinder safety risk assessment failure mode and effect analysis(FMEA) fatigue analysis
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Study on the inflammatory cytokines after heterotopic transplantation of isolated mouse heart preserved in a high-pressured mixed gas chamber
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作者 张瑞 黄帅 +6 位作者 LIU Zhen-ling ZHAO Ming-yi 郑少忆 郭惠明 陈寄梅 庄建 朱平 《South China Journal of Cardiology》 CAS 2015年第2期122-129,136,共9页
Background The maintenance of heart viability is important for heart transplantation. Currently, heart preservation is limited to 6 hours of cold ischemic storage. This study explored a new heart preservation method u... Background The maintenance of heart viability is important for heart transplantation. Currently, heart preservation is limited to 6 hours of cold ischemic storage. This study explored a new heart preservation method under a high-pressured mixed gas chamber. Methods C57BL/6 male mice were used to establish the model of mice cervical heterotopic heart transplantation. Adult donor mice were randomly divided into three groups subjected to naive operation (Group A), standard control (Group B) and experimental control (Group C). The recipient mice were randomly divided into two groups subjected to standard control and experimental control. Group A: hearts were isolated; Group B: hearts were isolated and preserved in HTK solution at 4 ℃ for 8 h and transplanted; Group C: hearts were isolated and preserved in high pressured gas (PO2:3200 hPa + PCO: 800 hPa = 4000 hPa) at 4 ℃ for 8h and transplanted. After transplantation, the state of re-beating and cardiac function were observed for Group B and C. At 24 h after transplantation, samples were collected for HE staining, cardiac cell apoptosis detection by Tunnel staining and analysis of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) and interleukin-10 (IL-10) by reverse transcriotion-polymerase chain reaction (RT-PCR). Results In group C, 15 transplanted hearts were re-beat, while only 6 in Group B. The re-beating rate in Group C was significantly higher than Group B [75.0%(15/20) vs. 30.0%(6/20) ,P = 0.01]. The time of re-beating was significantly different between Group B, and C [(352.35 ± 61.07)s vs. (207.85 ± 71.24) s, P 〈 0.011. HE staining showed that pathologic changes such as ceil edema and inflammatory cell infiltration were more obvious in Group B and C than in Group A, but less obvious in Group C compared with Group B. Tunnel staining showed that Group B had more obvious apoptosis than Group A and C. RT-PCR results showed significant increase of TNF-α, IL-1β and IL-6 expression in Group B than Group C (P 〈 0.01, the expression of IL-10 was higher in Group C than that in Group B. Conclusion Highpressured mixed gas (PO2:3200 hPa + PCO: 800 hPa = 4000 hPa) preservation can reduce cold ischemia and reperfusion injury of donor heart, therefore to maintain myocardial viability and prolong preservation time of donor heart. 展开更多
关键词 high-pressured mixed gas preservation carbon monoxide isolated heart preservation cold ischemia and reperfusion injury INFLAMMATION apoptosis
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Seal contact performance analysis of soft seals on high-pressure hydrogen charge valves 被引量:3
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作者 Zhen-hao LIN Long-jie YU +2 位作者 Ting-feng HUA Zhi-jiang JIN Jin-yuan QIAN 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2022年第4期247-256,共10页
The charge valve is an important element in the charging port of a high-pressure hydrogen storage cylinder(HP-HSC).It is normally closed after the HP-HSC is filled with hydrogen.If the seal of the charge valve is dama... The charge valve is an important element in the charging port of a high-pressure hydrogen storage cylinder(HP-HSC).It is normally closed after the HP-HSC is filled with hydrogen.If the seal of the charge valve is damaged,it will seriously affect the stable operation of the hydrogen supply system and may even cause safety problems.Therefore,the seal performance of the charge valve is important.In this paper,finite element analysis(FEA)is carried out to analyze the seal contact performance of hydrogenated nitrile rubber(HNBR)gaskets in the seal pair of a charge valve.The effects of different pre-compressions,seal widths,and hydrogen pressures on the seal contact performance of the charge valve are analyzed.The contact pressure on the seal surface increases with the increase of pre-compression.With a pre-compression of 2.5 mm,the maximum contact pressure without and with hydrogen pressure are 68.51 and 107.38 MPa,respectively.A contact gap appears in the inner ring of the seal surface with pre-compression below 0.15 mm.The contact gap occurs between the entire seal surface with a seal width of1 mm.The contact pressure on the seal surface and the width of the separation area between the seal surfaces increase with the increase of the seal width.The contact gap between the seal surfaces is zero with a width of 2.5 mm.The width of the separation area between the seal surfaces decreases with the decrease of the hydrogen pressure.The width of the separation area is reduced from 0.5 mm at 35 MPa to 0.17 mm at 15 MPa.This work can be useful for improvement of the seal performance and of the design of the charge valve used in the HP-HSC. 展开更多
关键词 Charge valve Seal contact performance high-pressure hydrogen storage cylinder(HP-HSC) Finite element analysis(FEA)
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Effect of particle size on high-pressure methane adsorption of coal 被引量:4
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作者 Jie Zou Reza Rezaee 《Petroleum Research》 2016年第1期53-58,共6页
Adsorbed gas cannot be neglected in the evaluation of coalbed methane and shale gas since a significant proportion of gas is stored in the form of adsorbed gas.Adsorbed methane of coal and shale has been widely studie... Adsorbed gas cannot be neglected in the evaluation of coalbed methane and shale gas since a significant proportion of gas is stored in the form of adsorbed gas.Adsorbed methane of coal and shale has been widely studied by high-pressure methane adsorption experiment.In sample treatment of the experiment,the sample is crushed and sieved to a particular particle size range.However,how particle size influence high-pressure methane adsorption is still unclear.In this study,low-pressure nitrogen(N_(2))and high-pressure methane adsorption have been measured on coal samples with different particle size.According to N2 sorption analysis,pore volume and surface area increase with particle size reduction.Pore size distribution of small pores(<10nm)changes among varying particle size.Pore volume proportion of small pores(<10nm)increases and pore volume proportion of big pores(>10nm)decreases with decreasing particle size.Decreasing particle size by crushing sample introduces new connectivity for closed pores to the particle surface.The responses of isotherms of high-pressure methane adsorption are different with different particle size.Methane adsorption at initial pressure(145psi)increases with decreasing particle size.Adsorption increase rate at high pressure(435-870psi)decreases with particle size reduction.This can be explained that fine sample has more pore volume and higher pore volume proportion of small pores(<10nm).Sample with particle size of 150-250μm has the highest Langmuir volume. 展开更多
关键词 particle size high-pressure methane adsorption COAL shale gas
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