This study examines the thermal runaway of a lithium ion battery caused by poor heat dissipation performances.The heat transfer process is analyzed on the basis of standard theoretical concepts.Water mist additives ar...This study examines the thermal runaway of a lithium ion battery caused by poor heat dissipation performances.The heat transfer process is analyzed on the basis of standard theoretical concepts.Water mist additives are considered as a tool to suppress the thermal runaway process.The ensuing behaviour of the battery in terms of surface temperature and heat generation is analyzed for different charge and discharge rates.It is found that when the remaining charge is 100%,the heat generation rate of the battery is the lowest,and the surface temperature with a 2C charge rate is higher than that obtained for a 0.5C charge rate.The experimental results show that when the additive concentration is 20%NaCl,its ability to inhibit the thermal runaway is the strongest.展开更多
Gas-liquid two-phase flow is ubiquitous in the process of oil and gas exploitation,gathering and transportation.Flow pattern,liquid holdup and pressure drop are important parameters in the process of gas-liquid two-ph...Gas-liquid two-phase flow is ubiquitous in the process of oil and gas exploitation,gathering and transportation.Flow pattern,liquid holdup and pressure drop are important parameters in the process of gas-liquid two-phase flow,which are closely related to the smooth passage of the two-phase fluid in the pipe section.Although Mukherjee,Barnea and others have studied the conventional viscous gas-liquid two-phase flow for a long time at home and abroad,the overall experimental scope is not comprehensive enough and the early experimental conditions are limited.Therefore,there is still a lack of systematic experimental research and wellbore pressure for gas-liquid two-phase flow under the conditions of middle and high yield and high gas-liquid ratio in conventional viscosity,and the prediction accuracy is low.In view of this,this study carried out targeted systematic research,and from the flow pattern,liquid holdup and pressure drop aspects,established the relevant model,obtained a set of inclined wellbore gas-liquid two-phase pipe flow dynamic prediction method.At the same time,firstly,the model is tested by experimental data,and then the model is compared and verified by a number of field measured wells,which proves that the model is reliable and the prediction accuracy of wellbore pressure is high.展开更多
The design of an aircraft’s aerodynamic configuration has a direct influence on the flight performance and quality,not to mention a decisive influence on flight safety,efficiency,and economic benefits.The fundamental...The design of an aircraft’s aerodynamic configuration has a direct influence on the flight performance and quality,not to mention a decisive influence on flight safety,efficiency,and economic benefits.The fundamentals of aerodynamic design involve the inverse problem of aerodynamics.Before the 1960s,aerodynamic design depended largely on a large number of wind-tunnel tests combined with the engineering experience of the designers,and employing the so-called trial-and-error method.Along with the development of modern computing technology,computational fluid dynamics(CFD)has played an increasingly important role in aerodynamic calculation,analysis,and design.展开更多
The flow past a fixed single transmission conductor and the related heat transfer characteristics are investigated using computational fluid dynamics and a relevant turbulence model.After validating the method through...The flow past a fixed single transmission conductor and the related heat transfer characteristics are investigated using computational fluid dynamics and a relevant turbulence model.After validating the method through comparison with relevant results in the literature,this thermofluid-dynamic problem is addressed considering different working conditions.It is shown that the resistance coefficient depends on the Reynolds number.As expected,the Nusselt number is also affected by Reynolds number.In particular,the Nusselt number under constant heat flux is always greater than that under a constant wall temperature.展开更多
文摘This study examines the thermal runaway of a lithium ion battery caused by poor heat dissipation performances.The heat transfer process is analyzed on the basis of standard theoretical concepts.Water mist additives are considered as a tool to suppress the thermal runaway process.The ensuing behaviour of the battery in terms of surface temperature and heat generation is analyzed for different charge and discharge rates.It is found that when the remaining charge is 100%,the heat generation rate of the battery is the lowest,and the surface temperature with a 2C charge rate is higher than that obtained for a 0.5C charge rate.The experimental results show that when the additive concentration is 20%NaCl,its ability to inhibit the thermal runaway is the strongest.
基金The authors like to express appreciation to the support given by the major national science and technology special project:National Natural Science Foundation of China“Complex System Identification and Optimum Design Based on Hybrid Data and Its Application in Low Permeability Oil Wells”(No.61572084)National Major Project“Lifting Technology and Matching Technology for Production Wells in Whole Life Cycle”(2016ZX056004-002)National Major Science and Technology Project(2017ZX05030-005).
文摘Gas-liquid two-phase flow is ubiquitous in the process of oil and gas exploitation,gathering and transportation.Flow pattern,liquid holdup and pressure drop are important parameters in the process of gas-liquid two-phase flow,which are closely related to the smooth passage of the two-phase fluid in the pipe section.Although Mukherjee,Barnea and others have studied the conventional viscous gas-liquid two-phase flow for a long time at home and abroad,the overall experimental scope is not comprehensive enough and the early experimental conditions are limited.Therefore,there is still a lack of systematic experimental research and wellbore pressure for gas-liquid two-phase flow under the conditions of middle and high yield and high gas-liquid ratio in conventional viscosity,and the prediction accuracy is low.In view of this,this study carried out targeted systematic research,and from the flow pattern,liquid holdup and pressure drop aspects,established the relevant model,obtained a set of inclined wellbore gas-liquid two-phase pipe flow dynamic prediction method.At the same time,firstly,the model is tested by experimental data,and then the model is compared and verified by a number of field measured wells,which proves that the model is reliable and the prediction accuracy of wellbore pressure is high.
文摘The design of an aircraft’s aerodynamic configuration has a direct influence on the flight performance and quality,not to mention a decisive influence on flight safety,efficiency,and economic benefits.The fundamentals of aerodynamic design involve the inverse problem of aerodynamics.Before the 1960s,aerodynamic design depended largely on a large number of wind-tunnel tests combined with the engineering experience of the designers,and employing the so-called trial-and-error method.Along with the development of modern computing technology,computational fluid dynamics(CFD)has played an increasingly important role in aerodynamic calculation,analysis,and design.
文摘The flow past a fixed single transmission conductor and the related heat transfer characteristics are investigated using computational fluid dynamics and a relevant turbulence model.After validating the method through comparison with relevant results in the literature,this thermofluid-dynamic problem is addressed considering different working conditions.It is shown that the resistance coefficient depends on the Reynolds number.As expected,the Nusselt number is also affected by Reynolds number.In particular,the Nusselt number under constant heat flux is always greater than that under a constant wall temperature.
