焊接孔长度对钢框架梁-柱刚性节点性能的影响

对焊接孔长度扩大的钢框架梁－柱刚性节点进行了空间非线性有限分析。分析结果表明，焊接孔长工的扩大显著地降低了梁－柱连接面处的对接焊缝和焊接孔切角端开裂以及翼缘脆性破坏的可能性，但过长的焊接孔也会导致梁侧向稳定的丧失。     

交巡警最短路径模型的建立

【目的】提高一般SPFA算法(Shortest Path Faster Algorithm)的效率,缩短出警时间。【方法】用离散化道路法优化辖区分配策略,在道路上设置虚拟路口,把每条道路离散成若干个点,然后把这些新增加的点作为新的路口,由此得到新的道路地图。【结果】多次仿真实验数据显示离散化的优化策略可以缩短出警时间。【结论】基于离散化的改进SPFA算法提高了一般SPFA算法的效率,优化了服务平台,具有一定的实用价值。     

75t/h 水冷方型分离器循环流化床锅炉物料平衡热态测试

利用自行设计的测试方法对第一台采用入口带有加速段的水冷方型分离器专利技术的７５ｔ／ｈ循环流化床锅炉物料平衡系统进行热态测试,包括分离器的分级分离效率、烟气对固体物料的携带率、固体物料循环量等。测试结果表明：该锅炉水冷方型分离器的分级分离效率与相同当量直径的常规圆形旋风筒的分级分离效率相近,但阻力下降约一半;该炉的固体物料循环量达到设计值并有一定调节裕度,完全满足燃烧和传热的要求。测试结果为该炉型的进一步放大提供了可靠的依据。     

Unburned Carbon Loss in Fly Ash of CFB Boilers Burning Hard Coal

The unburned carbon loss in fly ash of circulating fluidized bed (CFB) boilers, most of which are burning active fuels such as lignite or peat, is normally very low. However, most CFB boilers in China usually burn hard coals such as anthracite and bituminous coal and coal wastes, so the carbon content in the fly ash from these boilers is higher than expected. This paper investigates the source of unburned carbon in the fly ash of CFB boilers burning hard coal through a series of field tests and laboratory investigations. The char behavior during combustion, including fragmentation and deactivation, which is related to the parent coal, has an important impact on the carbon burnout in CFB boilers. The research shows that char deactivation occurs during char burnout in fluidized bed combustion, especially for large particles of low rank coal. The uneven mixing of solids and air in the core region of the furnace also causes poor burnout of carbon in CFB fly ash. An index describing the volatile content (as dry ash free basis) over the heating value is proposed to present the coal rank. The coal combustion efficiency is shown to be strongly connected with this coal index. Several changes in the CFB boiler design are suggested to reduce the unburned carbon loss in the fly ash.