摘要
城市测量中,按照国家6°或3°带的分带方法并以国家统一的6°或3°带高斯平面为归算面进行投影时,随着测区偏离中央子午线的距离增大、测区平均高程的增大,长度投影变形也将随着增大,因而在测图和测设工作时常需要进行长度改算。为了使投影变形尽可能地被控制在一个较小的范围内,测绘部门常常建立城市独立坐标系。本文探讨分析如何确定城市独立坐标系建立中的投影基准问题。
Based on 600 MW unit dry-type slag removal system, the author applied the method of computational fluid dynamics numerical simulation in the flow characteristics study. The slag layer on steel trip of dry-type slag removal system was approximately discharged into porous medium, and the machine structure was simplified reasonably. It shows that the numerical simulation results can reflect the internal flow of slag discharge machine, match with the actual situation, and provide the foundation for the research on heat transfer characteristics of slag discharge machine as well as its reform selection.
出处
《河北工程技术高等专科学校学报》
2014年第3期67-70,共4页
Journal of Hebei Engineering and Technical College Quarterly
关键词
独立坐标系
归化
投影
变形误差
dry-type slag removal system
numerical simulation
flow characteristics
