壁式工作面变向推进开采技术应用

针对西山镇城底矿由于地质条件复杂,断层密集,煤层破坏严重,造成的大量残留煤炭资源无法开采的技术难题,在22113综放工作面采用变向推进方法,实现了边角煤的安全、高效、合理回采,取得了良好的技术效果和显著的经济效益。

镇城底煤矿综采工作面变向推进技术

针对镇城底煤矿22113不规则工作面煤炭资源回收问题,提出了综采工作面变向开采推进技术并进行了现场应用,结果表明,变向开采推进技术避免了综采工作面搬家倒面,降低了生产成本,减少了煤炭资源丢失,延长了矿井服务年限。

长壁综采工作面变向推进回采技术实践

对变向推进回采技术在井田边角煤的回收领域的适用性进行了深入研究,在不断摸索试验的基础上,提出了长壁综采工作面方向二次改变回采技术,相应地突破了工作面调斜与胶带转弯技术,并成功地实现了在矿井边角区段布置变向推进长壁综采工作面的目标。生产实践表明,长壁综采工作面变向推进回采方法可有效提高井田边角煤的回采率、减少搬家倒面次数、缓解矿井生产接替紧张局面、降低生产成本。

Influence on the hydrodynamic performance of a variable vector propeller of different rules of pitch angle change

To design a more effective blade pitch adjustment mechanism,research was done on changes to the hydrodynamic characteristics of VVPs(Variable Vector Propeller) caused by different rules for changing pitch angle. A mathematical method for predicting the hydrodynamic characteristics of a VVP under unsteady conditions is presented based on the panel method. Mathematical models for evaluation based on potential flow theory and the Green theorem are also presented. The hydrodynamic characteristics are numerically predicted. To avoid gaps between panels,hyperboloidal quadrilateral panels were used. The pressure Kutta condition on the trailing edge of the VVP blade was satisfied by the Newton-Raphson iterative procedure. The influence coefficients of the panels were calculated by Morino's analytical formulations to improve numerical calculation speed,and the method developed by Yanagizawa was used to eliminate the point singularity on derivation calculus while determining the velocities on propeller surfaces. The calculation results show that it's best for the hydrodynamic characteristics of the VVP that pitch angle changes follow the sine rule.