High-speed trains operating in freezing rain are highly susceptible to severe ice accretion in the pantograph region,which compromises both power transmission efficiency and dynamic performance.To elucidate the underl...High-speed trains operating in freezing rain are highly susceptible to severe ice accretion in the pantograph region,which compromises both power transmission efficiency and dynamic performance.To elucidate the underlying mechanisms of this phenomenon,an Euler-Euler multiphase flow model was employed to simulate droplet impingement and collection on the pantograph surface,while a glaze-ice formation model incorporating wall film dynamics was used to capture the subsequent growth of ice.The effects of key parameters—including liquid water content,ambient temperature,train velocity,and droplet diameter—on the amount and morphology of ice were systematically investigated.The results show that ice accumulation intensifies with increasing liquid water content decreasing ambient temperature,and rising train speed.In contrast,larger droplet diameters reduce the overall ice mass but promote localized accretion on major structural elements.This behavior arises because larger droplets,with greater inertia,are less susceptible to entrainment by airflow into the pantograph's base region.During extended operation,substantial ice buildup develops on the pantograph head and upper and lower arms,severely impairing current collection from the overhead line and hindering the pantograph's lifting and lowering motions.展开更多
Climate room is an important instrument to study the icing problems in power networks,and the accuracy of the data from the climate room is under debate.There are many climate rooms in the world,but no standards about...Climate room is an important instrument to study the icing problems in power networks,and the accuracy of the data from the climate room is under debate.There are many climate rooms in the world,but no standards about the parameters of the climate room such as the room's temperature,the velocity of the wind,and the particle diameters of the water droplets etc.These parameters will influence the icing processes on the lines and insulators.This paper gave a summary of the process and the feature of atmospheric icing of power networks.The speed of the icing on a cylinder rod as a new characteristic quantity was proposed to study the de-icing problems in this paper.For the purpose to analyze the equivalence between atmospheric icing and icing in climate room,a finite element model was made based on a small climate room located in the Graduate School at Shenzhen,Tsinghua University.Through the simulation analysis for the heat transfer and flow issues,the result showed that precooling droplets were cooled into supercooled ones soon after they came into the climate room.Based on the most serious icing-speed in Hengshan,Hunan and a series of experiments,the values of some parameters in studying icing problems were proposed to better simulate the atmospheric icing in climate room.展开更多
基金Natural Science Foundation of Shandong Province(Grant No.ZR2022ME180)the National Natural Science Foundation of China(Grant No.51705267).
文摘High-speed trains operating in freezing rain are highly susceptible to severe ice accretion in the pantograph region,which compromises both power transmission efficiency and dynamic performance.To elucidate the underlying mechanisms of this phenomenon,an Euler-Euler multiphase flow model was employed to simulate droplet impingement and collection on the pantograph surface,while a glaze-ice formation model incorporating wall film dynamics was used to capture the subsequent growth of ice.The effects of key parameters—including liquid water content,ambient temperature,train velocity,and droplet diameter—on the amount and morphology of ice were systematically investigated.The results show that ice accumulation intensifies with increasing liquid water content decreasing ambient temperature,and rising train speed.In contrast,larger droplet diameters reduce the overall ice mass but promote localized accretion on major structural elements.This behavior arises because larger droplets,with greater inertia,are less susceptible to entrainment by airflow into the pantograph's base region.During extended operation,substantial ice buildup develops on the pantograph head and upper and lower arms,severely impairing current collection from the overhead line and hindering the pantograph's lifting and lowering motions.
基金Project Supported by National Natural Science Foundation of China(51077081)
文摘Climate room is an important instrument to study the icing problems in power networks,and the accuracy of the data from the climate room is under debate.There are many climate rooms in the world,but no standards about the parameters of the climate room such as the room's temperature,the velocity of the wind,and the particle diameters of the water droplets etc.These parameters will influence the icing processes on the lines and insulators.This paper gave a summary of the process and the feature of atmospheric icing of power networks.The speed of the icing on a cylinder rod as a new characteristic quantity was proposed to study the de-icing problems in this paper.For the purpose to analyze the equivalence between atmospheric icing and icing in climate room,a finite element model was made based on a small climate room located in the Graduate School at Shenzhen,Tsinghua University.Through the simulation analysis for the heat transfer and flow issues,the result showed that precooling droplets were cooled into supercooled ones soon after they came into the climate room.Based on the most serious icing-speed in Hengshan,Hunan and a series of experiments,the values of some parameters in studying icing problems were proposed to better simulate the atmospheric icing in climate room.
