The compressible miscible displacement in a porous media is considered in this paper. The problem is a nonlinear system with dispersion in non-periodic space. The concentration is treated by a characteristics collocat...The compressible miscible displacement in a porous media is considered in this paper. The problem is a nonlinear system with dispersion in non-periodic space. The concentration is treated by a characteristics collocation method, and the pressure is treated by an orthogonal collocation method. Optimal order estimates are derived.展开更多
文摘The compressible miscible displacement in a porous media is considered in this paper. The problem is a nonlinear system with dispersion in non-periodic space. The concentration is treated by a characteristics collocation method, and the pressure is treated by an orthogonal collocation method. Optimal order estimates are derived.
文摘对某厂330 MW机组凝汽器改造前向心形管束布置和改造后TEPEE两山峰形管束布置的壳侧汽相流动与传热进行了数值模拟与比较.结果表明:改造前凝汽器结构设计不合理,上部管束得不到充分利用,导致凝汽器性能差;改造后TEPEE两山峰形管束布置使压降分布均匀,传热系数增大,更有利于凝汽器壳侧蒸汽的流动与传热.改造前后的性能试验结果表明:采用TEPEE两山峰形管束布置方式的凝汽器,其性能指标达到设计值,优于向心形管束布置方式;改造后凝汽器真空比改造前提高了1.743 kPa,端差下降4.63 K.