煤粉注入式粗粉分离器的设计与实验研究

Design and Experimental Study of a Pulverized-coal Injection Type Coarse Powder Separator

针对燃用劣质煤的315 MW"W"火焰锅炉所配双进双出钢球磨煤机直吹式制粉系统出力不足及煤种负荷适应性较差的问题,提出了将原直吹式制粉系统改为"储仓-直吹式"制粉系统的方案,该方案要求研究开发一高性能的煤粉注入式粗粉分离器。为此,本研究设计了两种典型的煤粉注入式粗粉分离器及3种内部导流装置,并对其进行了数值与物理模拟研究,结果表明:煤粉注入式粗粉分离器能够满足"储仓-直吹式"制粉系统的技术要求;加高型注入式分离器内的流动阻力对内部导流装置结构尺寸的变化不甚敏感,阻力变化仅20 Pa左右,而基于原型结构的注入式粗粉分离器对内部导流装置结构尺寸的变化较敏感,阻力变化高达183Pa;原型结构与加高型结构注入式分离器的内部流动阻力差最大达163 Pa。

In the light of such problems of the dual inlet and outlet ball-mill-based direct-fired milling system of a 315 MW 'W' type flame boiler burning low quality coal as insufficient power output and poor adaptability to various coal ranks and burdens,presented was a version to modify the original direct-fired milling system to a 'cabin-direct-fired' milling system,which required to develop a high performance pulverized coal injection type coarse powder separator.For this purpose,the researchers designed two typical pulverized coal injection type coarse powder separators and three types of inner flow guide device and conducted a numerical and physical simulation study.The research results show that the pulverized coal injection type coarse powder separator thus designed can meet the technical requirements for a 'cabin-direct-fired' milling system.The flow resistance inside the heightened injection type separator is not quite susceptible to any change of the structural dimensions of the inner flow guide device and the variation range of the resistance is only around 20 Pa while the prototype of the injection type coarse powder separator is susceptible to any change of the structural demensions of the inner flow guide device and the variation range of the resistance is as high as 183 Pa.The biggest difference of the inner flow resistance between the prototype and the heightened injection type coarse powder separator is 163 Pa.