盾构刀盘上方地层无变形的平衡压力理论计算

在原论文盾构开挖面无变形平衡压力计算的基础上,以现今常用的周边圆弧形刀盘开挖面上方地层不变形为前提,推导出盾构掘进动态条件下刀盘开挖面任一点平衡压力值与平衡压力范围,并提出主动平衡压力与被动平衡压力的概念,确定了盾构掘进上方地层不变形周边圆弧形刀盘盾构土舱压力的取值。给出了圆弧形开挖面主动平衡压力与被动平衡压力的计算方法。最后,得出周边圆弧形刀盘盾构平衡压力主要取决于开挖面拱顶上方原状土自重应力的结论。

对盾构轴线控制技术的理解和应用

该文分析了盾构在地层中的受力状况、盾构推进时受到的阻力。根据多年施工实践,证明盾构在正面土体性质软、硬均匀地层中推进施工,用纵坡调整及调整千斤顶伸出长度差来控制盾构轴线位置,是一项最佳也是最简便、有效的技术,也是目前最常用的技术措施。为提高施工速度,对盾构机机构提出了改进意见。

确定高温高压井中盐水浓度的方法

介绍了一种适用于氯化钠溶液的压力浓度温度状态方程。我们可以把公式中的经验系数作为重量百分数 (W)的函数来计算。根据测量到的井下压力和井温剖面图 ,可以计算出所需要的盐水浓度。在高温高压井中 ,如果掌握了井下压力与井温、井深和产生压力的盐水的浓度的函数关系 ,便可以精确控制过平衡压力值。

Numerical Investigation on Wet Steam Non-equilibrium Condensation Flow in Turbine Cascade

Based on the two-phase wet steam flow with spontaneous condensation, experimental verification and flow analysis on nozzle and 2D cascade are carried out. The 3D Reynolds-Averaged gas-liquid two-phase flow control equation solver is explored with k-e-kp turbulence model. Furthermore, 3D flow numerical simulation on the last stage stator of the steam turbine is carried out. The results show that a sudden pressure rise on blade suction surface is mainly caused by the droplet growth in condensation flow. The more backward the condensation position is in cascade passage, the less the sudden pressure rise from condensation is, and the larger the nucleation rate is, the maximum under-cooling and the number of droplets per unit volume are. Interaction of condensation wave and shock wave has imposed greater influence on the parameters of the blade cascade outlet.