【摘要】 在9-22 MPa亚临界压力区,基于Fortran程序针对不同螺纹结构的垂直上升内螺纹管汽水单相和两相流动的摩擦压降特性进行数值对比研究.研究表明:螺纹结构对内螺纹管的流动特性有显著影响;与光管相比,内螺纹管有较大的摩擦系数,摩擦系数随着内螺纹管螺纹当量N的增加而增大;内螺纹管的两相摩擦压降倍率φl02在低干度值时受N值影响较小,压强越大,差距越小;φl02随压力增大而减小,随蒸汽干度χ增加2l0φ先增加,随后增幅减小,在χ>0.9时有下降的趋势.研究结果为动力工程中内螺纹管的优化提供理论依据.更多还原

【Abstract】 At sub-critical pressure region of 9～22MPa,the frictional pressure drop characteristics of single phase water flow and steam-water two-phase flow in internally-ribbed tubes with different thread structure were numerically investigated by Fortran.The numerical results show that threads in the internally-ribbed tubes have significant effects on flow characteristics.Compared to internally-ribbed tubes,smooth tubes have larger frictional coefficient,and the frictional coefficient decreases with rising thread equivalent N.The two-phase multiplier φl02 is less affected by thread equivalent N while decreases with rising pressure when the steam quality is small.The two-phase multiplier φl02 decreases with rising pressure,and first increases quickly then slow down with rising steam quality.The two-phase multiplier starts to decrease when the steam quality χ is greater than 0.9.The results of the study provide theoretical basis for the optimization of internally ribbed tubes.更多还原