中文摘要：

为了提高掘进机外喷雾降尘效率，降低煤矿掘进工作面生产时产生的大量粉尘。改善工作面工作环境及人体健康，提高掘进机截割头的使用寿命。抑制由于粉尘浓度达到一定程度后而发生粉尘爆炸情况造成的人身财产的重大损失；为了避免过多的雾滴落在截割机构上造成水的浪费。令喷雾截面圆与大端面圆近似相切，并保证喷雾覆盖区域相互重叠1／4、捕集区的喷雾截面积近似为环形、雾流形状在有效的作用区内为圆锥形以及喷雾捕集区的粉尘分布是均匀的。建立了掘进机外喷雾降尘效率的数学模型，选择喷雾压力、喷雾有效作用区的长度、喷雾扩散角度以及喷嘴的直径为设计参数。以掘进机外喷雾降尘效率最大为优化目标，建立了相应的约束条件。并且将优化模型进行了无约束化处理。采用遗传算法对影响掘进机外喷雾降尘效率的主要参数进行了优化。优化结果表明。喷雾压力增大了9．79％。喷雾作用区的长度降低了8％，雾化角度减小了11．15％，掘进机外喷雾的降尘效率增加了15．19％。该研究为工程实践提供了理论基础，为掘进机外喷雾系统结构参数的整体优化，使其整体功能达到最佳状态提供了依据。并且对于掘进机内喷雾系统的建模及优化方法提供了重要参考。具有一定的指导意义。

英文摘要：

In order to improve the efficiency of reducing dust for roadheader external spray, reduce amounts of dust in coal heading face, better mining working face environment and hunmn health, enhance cutting head service life of the roadheader, the mathematical models of the efficiency for reducing dust are established for roadheader external spray, the main influence parameters of efficiency of reducing dust for roadheader external spray are optimized by using genetic algorithm and by taking the spray pressure, spray effective length, spray diffusion angle, and nozzle diameter as design parameters, the maximum efficiency of reducing dust for roadheader external spray is chosen as optimal objective. Corresponding constraint conditions are established, and the optimization model is processed without constraints. Optimized results indicate while the spray pressure increases 9.79%, the spray effective length reduces 8%; the spray diffusion angle reduces 11.15%, and the efficiency of reducing dust increases 15,19% for roadheader external spray. The study provides a theory basis for engineering practice, offers the basis both for the entire optimization of the structural parameters of roadheader external spray system and for the entire functions reaching at their best, and furnishes important reference for modeling and optimizing methods of roadheader internal spray system with some guidance significanees.