Recently,natural draft dry cooling system with the main-auxiliary integrated air-cooled heat exchangers in the up and lower layers,has drawn attention to the electric power industry.This research firstly develops two ...Recently,natural draft dry cooling system with the main-auxiliary integrated air-cooled heat exchangers in the up and lower layers,has drawn attention to the electric power industry.This research firstly develops two physical models for the integrated cooling system,namely Case A and Case B.In Case A,the main air-cooled heat exchanger is arranged in the upper layer and the auxiliary air-cooled heat exchanger arranged in the lower layer,while in Case B,the two heat exchanger systems are arranged in the opposite way.And then,directing at the engineering TMCR and TRL 1 working conditions,the unit-local-overall thermo-flow characteristics of Case A and Case B are obtained and compared by numerical simulation.The findings show that,for the auxiliary air-cooled exchanger,Case A has obviously higher cooling performances than Case B,with the difference varying from 5.46%to 7.55%.Whereas,for the main air-cooled exchanger,Case B shows the recovered cooling performances,with the difference changing from 1.15%to 2.99%.Case A is preferably recommended to the engineering application in consideration of more strict cooling demand of the auxiliary cooling system.Conclusively,this research will provide some theoretical guidelines for the design and construction of the main-auxiliary integrated natural draft dry cooling system.展开更多
A kind of closed-loop Hall effect sensor is designed and fabricated by considering several factors such as iron core material,Hall device,as well as selected integrated circuit.Through studying the effect of the iron ...A kind of closed-loop Hall effect sensor is designed and fabricated by considering several factors such as iron core material,Hall device,as well as selected integrated circuit.Through studying the effect of the iron material and structures of current sensor,a kind of optimal Hall effect current sensor is found.The experimental results show that the presented closed-loop Hall effect current sensor achieves 1 mA/A sensitivity.And its linearity and accuracy are 0.1%and 0.35%FS,respectively,at currents ranging from 0 to 50 A.展开更多
基金The financial supports for this research,from the National Natural Science Foundation of China(Grant No52006065)Fundamental Research Funds for Central Universities(2022BJ0273,2023JC001)。
文摘Recently,natural draft dry cooling system with the main-auxiliary integrated air-cooled heat exchangers in the up and lower layers,has drawn attention to the electric power industry.This research firstly develops two physical models for the integrated cooling system,namely Case A and Case B.In Case A,the main air-cooled heat exchanger is arranged in the upper layer and the auxiliary air-cooled heat exchanger arranged in the lower layer,while in Case B,the two heat exchanger systems are arranged in the opposite way.And then,directing at the engineering TMCR and TRL 1 working conditions,the unit-local-overall thermo-flow characteristics of Case A and Case B are obtained and compared by numerical simulation.The findings show that,for the auxiliary air-cooled exchanger,Case A has obviously higher cooling performances than Case B,with the difference varying from 5.46%to 7.55%.Whereas,for the main air-cooled exchanger,Case B shows the recovered cooling performances,with the difference changing from 1.15%to 2.99%.Case A is preferably recommended to the engineering application in consideration of more strict cooling demand of the auxiliary cooling system.Conclusively,this research will provide some theoretical guidelines for the design and construction of the main-auxiliary integrated natural draft dry cooling system.
基金supported by the National Basic Research Program of China("973"Project)(Grant No.2011CB309504)the National Key Project of Semiconductor Equipment(02)(Grant No.2009ZX02037)
文摘A kind of closed-loop Hall effect sensor is designed and fabricated by considering several factors such as iron core material,Hall device,as well as selected integrated circuit.Through studying the effect of the iron material and structures of current sensor,a kind of optimal Hall effect current sensor is found.The experimental results show that the presented closed-loop Hall effect current sensor achieves 1 mA/A sensitivity.And its linearity and accuracy are 0.1%and 0.35%FS,respectively,at currents ranging from 0 to 50 A.
