How to uniformly distribute the liquid-solid two-phase flow is a difficulty which restricts the development of the liquid-solid fluidized bed.An Eulerian multiphase model incorporating the kinetic theory for solid par...How to uniformly distribute the liquid-solid two-phase flow is a difficulty which restricts the development of the liquid-solid fluidized bed.An Eulerian multiphase model incorporating the kinetic theory for solid particles was used to simulate the liquid-solid two-phase flow.The hydrodynamics in the lower vessel in a two-dimensional liquid-solid fluidized bed heat exchanger was simulated with the CFD method.The structural parameters of the liquid-solid distributor was optimized by simulation methods.The simulation results were in relatively good agreement with the experiments.The results indicated that when the angle of the V baffle was less than slide angle,the hole ratio of perforated plate was about 35% and the hole diameter was about 12 mm,the unevenness of solids volume fraction in the lower vessel was the least.展开更多
文摘为掌握大型循环流化床(circulating fluidized bed,CFB)锅炉外置换热器(fluidized bed heat exchanger,FBHE)的运行特性,在2台实际运行的300MW CFB锅炉上进行了运行特性测试研究,包括FBHE对CFB锅炉床温、汽温的调节及其传热特性的研究。结果表明:带FBHE的CFB锅炉炉膛温度沿炉膛高度分布比较均匀,且在60%锅炉最大连续蒸发量(boiler maximum continue rate,BMCR)以上运行时床温无明显变化,而无FBHE的CFB锅炉床温随负荷变化明显,炉膛温度沿炉膛高度差别较大,且随着锅炉负荷的降低,差别更明显;锥型阀的开度随锅炉负荷的增加而增大;在负荷不变的情况下,过热器的喷水量和再热器的吸热量随床温的升高递减,但减少幅度较小;不同负荷下FBHE内不同受热面的传热系数不同,其值均随负荷的增加单调增大。
文摘How to uniformly distribute the liquid-solid two-phase flow is a difficulty which restricts the development of the liquid-solid fluidized bed.An Eulerian multiphase model incorporating the kinetic theory for solid particles was used to simulate the liquid-solid two-phase flow.The hydrodynamics in the lower vessel in a two-dimensional liquid-solid fluidized bed heat exchanger was simulated with the CFD method.The structural parameters of the liquid-solid distributor was optimized by simulation methods.The simulation results were in relatively good agreement with the experiments.The results indicated that when the angle of the V baffle was less than slide angle,the hole ratio of perforated plate was about 35% and the hole diameter was about 12 mm,the unevenness of solids volume fraction in the lower vessel was the least.
