摘要
针对循环湍动流化床关键截面的气-固两相流动特性测定缺乏相应的理论作为依据,测定的准确度低,影响循环湍动流化床的应用,导致气固之间传质传热性能差问题,提出一种利用激光-光纤对循环湍动流化床关键截面气固两相流动特性进行测定的方法,通过利用Diaspora曳力模型计算流体曳力、利用经验关系式计算气固对流传热通量,并采用中心探测法实现对循环湍动流化床关键截面中空隙率的计算,以流体曳力、气固对流传热通量、以及空隙率的计算结果为依据,建立循环湍动流化床关键截面气-固两相流动的动力学模型,在此基础上,利用有线容积法,确定循环湍动流化床关键截面气-固两相流动对流扩散问题的控制方程,提高循环湍动流化床关键截面的气-固两相流动特性测定的准确度。实验结果表明,本文所提方法能够准确实现对循环湍动流化床关键截面中气-固颗粒的流动特性测定,完成对气-固两相流动特性的测定。
Aiming at the lack of corresponding theory in the determination of the gas-solid two-phase flow characteristics of the critical cross section of the cyclonic turbulent fluidized bed, the accuracy of the measurement is low, which affects the application of the turbulent fluidized bed. The paper analyzes the flow characteristics of gas-solid two -phase flow in the critical section of the cyclonic turbulent fluidized bed by laser-fiber. By using the Gidaspow drag force model to calculate the fluid drag force, the empirical formula is used to calculate the gas and the calculation of the porosity in the critical cross section of the cyclonic turbulent fluidized bed is carried out by using the central detection method. Based on the calculation results of fluid drag force, gas-solid convection heat transfer flux and porosity. Based on this, the control of the convective diffusion problem of the gas-solid two-phase flow in the critical section of the cyclonic turbulent fluidized bed is determined by cable volume method. The dynamic model of the gas-solid twophase flow in the critical section of the turbulent fluidized bed is established to improve the accuracy of the gas-solid two-phase flow characteristics of the critical cross-section of the turbulent fluidized bed. The experimental results show that the proposed method can accurately measure the flow characteristics of gas-solid particles in the critical cross-section of the cyclonic turbulent fluidized bed and finish the determination of gas-solid two-phase flow characteristics.
出处
《激光杂志》
北大核心
2017年第12期63-66,共4页
Laser Journal
基金
四川省科技支撑计划(2015GZ0037)
四川省重点实验室开放基金(GK201608)
四川理工学院创新基金(y2016018)
关键词
光纤-激光
循环湍动流化床
关键截面
气-固两相流动特性
fiber-laser
cyclic turbulent fluidized bed
critical section
gas-solid two-phase flow characteristics
