For the nitrogen oxide removal processes,high performance gas mixer is deeply needed for the injection of NH3 or O3.In this study,a new type of double swirl static mixer in gas mixing was investigated using computatio...For the nitrogen oxide removal processes,high performance gas mixer is deeply needed for the injection of NH3 or O3.In this study,a new type of double swirl static mixer in gas mixing was investigated using computational fluid dynamics(CFD).The results obtained using Particle Image Velocimetry(PIV)correlated well with the results obtained from simulation.The comparisons in pressure loss between the experimental results and the simulation results showed that the model was suitable and accurate for the simulation of the static mixer.Optimal process conditions and design were investigated.When L/D equaled 4,coefficient of variation(COV)was<5%.The inlet velocity did not affect the distributions of turbulent kinetic energy.In terms of both COV and pressure loss,the inner connector is important in the design of the static mixer.The nozzle length should be set at 4 cm.Taking both COV and pressure loss into consideration,the optimal oblique degree is 450.The averaged kinetic energy changed according to process conditions and design.The new static mixer resulted in improved mixing performance in a more compact design.The new static mixer is more energy efficient compared with other SV static mixers.Therefore,the double swirl static mixer is promising in gas mixing.展开更多
With the benefit fierce competition in the steel industry market in recent years,double cold reduction products have been developed towards strength improvement and thickness reduction.The traditional cold-rolling lub...With the benefit fierce competition in the steel industry market in recent years,double cold reduction products have been developed towards strength improvement and thickness reduction.The traditional cold-rolling lubrication process with a fixed flow rate and concentration cannot solve the problems,which are uncontrollable plate shape and the excessive consumption of lubricating oil.Moreover,based on the analysis of the traditional direct aplication lubrication system of double cold reduction mill,a set of design scheme suitable for the emulsion pipeline direct mixing lubrication system of double cold reduction mill unit was proposed.The design completed the selection of key components,which included the static mixer and atomization nozzle selection,pump and oil pump design selection,pipeline design selection,flow type selection,pressure gauge selection,electronic control cabinet design selection and other eight aspects.Equipment of the emulsion pipeline direct mixing lubrication system of double cold reduction has been developed.Comparing with characteristics of the traditional direct aplication lubrication system,the emulsion pipeline direct mixing lubrication system was better applied to the production practice of a 1220 double cold reduction mill.The consumption of ton of steel was reduced by 9.6%.The rolling energy consumption and fuel consumption comprehensive costs decreased by 10.7%,and the strip steel section thickness difference was reduced by 19.3%.In addition,the plate shape quality defect rate decreased by 25.6%,otherwise creating a large economic benefit for the unit and promoting the application value.展开更多
基于0.15μm GaAs赝配高电子迁移率晶体管(p HEMT)工艺,设计了一款18~40 GHz的无源双平衡混频器。该混频器采用肖特基二极管构成的混频环和3耦合线Marchand巴伦的结构,提高工作带宽的同时也减小了芯片尺寸。当本振(LO)功率为14 d Bm、中...基于0.15μm GaAs赝配高电子迁移率晶体管(p HEMT)工艺,设计了一款18~40 GHz的无源双平衡混频器。该混频器采用肖特基二极管构成的混频环和3耦合线Marchand巴伦的结构,提高工作带宽的同时也减小了芯片尺寸。当本振(LO)功率为14 d Bm、中频(IF)频率为100 MHz时,常温下流片测试的各项参数典型值为上下变频模式下LO/射频(RF)频段覆盖18~40 GHz,带内变频损耗为-7 d B,1 d B压缩点功率值为10 d Bm,LO到RF端口的隔离度为-25 d B,同时其余各端口之间具有优良的隔离度。中频频率覆盖DC~20 GHz,芯片尺寸为1.63 mm×0.97 mm。展开更多
基金financially supported by National Key Research and Development Plan of China(2016YFC0204700)Key Project of Zhejiang Provincial Science and Technology Program+1 种基金Zhejiang Provincial“151”Talents ProgramProgram for Zhejiang Leading Team of S&T Innovation(Grant No.2013TD07)。
文摘For the nitrogen oxide removal processes,high performance gas mixer is deeply needed for the injection of NH3 or O3.In this study,a new type of double swirl static mixer in gas mixing was investigated using computational fluid dynamics(CFD).The results obtained using Particle Image Velocimetry(PIV)correlated well with the results obtained from simulation.The comparisons in pressure loss between the experimental results and the simulation results showed that the model was suitable and accurate for the simulation of the static mixer.Optimal process conditions and design were investigated.When L/D equaled 4,coefficient of variation(COV)was<5%.The inlet velocity did not affect the distributions of turbulent kinetic energy.In terms of both COV and pressure loss,the inner connector is important in the design of the static mixer.The nozzle length should be set at 4 cm.Taking both COV and pressure loss into consideration,the optimal oblique degree is 450.The averaged kinetic energy changed according to process conditions and design.The new static mixer resulted in improved mixing performance in a more compact design.The new static mixer is more energy efficient compared with other SV static mixers.Therefore,the double swirl static mixer is promising in gas mixing.
基金This work is supported by the Natural Science Foundation of Hebei Province(Grant No.E20160203385)the Heavy Machinery Collaborative Innovation Program(Grant No.ZX01-20140400-05)。
文摘With the benefit fierce competition in the steel industry market in recent years,double cold reduction products have been developed towards strength improvement and thickness reduction.The traditional cold-rolling lubrication process with a fixed flow rate and concentration cannot solve the problems,which are uncontrollable plate shape and the excessive consumption of lubricating oil.Moreover,based on the analysis of the traditional direct aplication lubrication system of double cold reduction mill,a set of design scheme suitable for the emulsion pipeline direct mixing lubrication system of double cold reduction mill unit was proposed.The design completed the selection of key components,which included the static mixer and atomization nozzle selection,pump and oil pump design selection,pipeline design selection,flow type selection,pressure gauge selection,electronic control cabinet design selection and other eight aspects.Equipment of the emulsion pipeline direct mixing lubrication system of double cold reduction has been developed.Comparing with characteristics of the traditional direct aplication lubrication system,the emulsion pipeline direct mixing lubrication system was better applied to the production practice of a 1220 double cold reduction mill.The consumption of ton of steel was reduced by 9.6%.The rolling energy consumption and fuel consumption comprehensive costs decreased by 10.7%,and the strip steel section thickness difference was reduced by 19.3%.In addition,the plate shape quality defect rate decreased by 25.6%,otherwise creating a large economic benefit for the unit and promoting the application value.
文摘基于0.15μm GaAs赝配高电子迁移率晶体管(p HEMT)工艺,设计了一款18~40 GHz的无源双平衡混频器。该混频器采用肖特基二极管构成的混频环和3耦合线Marchand巴伦的结构,提高工作带宽的同时也减小了芯片尺寸。当本振(LO)功率为14 d Bm、中频(IF)频率为100 MHz时,常温下流片测试的各项参数典型值为上下变频模式下LO/射频(RF)频段覆盖18~40 GHz,带内变频损耗为-7 d B,1 d B压缩点功率值为10 d Bm,LO到RF端口的隔离度为-25 d B,同时其余各端口之间具有优良的隔离度。中频频率覆盖DC~20 GHz,芯片尺寸为1.63 mm×0.97 mm。
