不同截割工况下变速截割采煤机截割性能多目标优化

为了在不同截割工况下实现采煤机安全运行和高效生产,以牵引速度、滚筒转速为优化变量,以齿轮动载荷、采煤生产率、块煤率以及截割比能耗为子目标,建立了采煤机截割性能多目标优化模型;提出了基于权重系数轮换的各性能子目标权重系数的寻优方法,以确定适应不同截割工况的最优权重组合。利用遗传算法优化得到正常煤层、夹矸煤层和岩石断层工况下随截割阻抗变化的最优牵引-截割运动参数,并对比分析最优运动参数控制和传统牵引调速控制下采煤机的截割性能。结果表明,与传统牵引调速控制相比,采用最优运动参数控制不但明显提高了正常煤层和夹矸工况下的采煤经济性能,而且可安全快速通过断层区;此外,滚筒转速在24 r/min附近时截割传动系统出现局部共振,因此滚筒变速截割时应避免在共振转速下运行。所得结果为采煤机自适应变速截割的实施提供参考。

Multi-objective optimization for cutting performance of the variable speed cutting shearer under different conditions

In order to realize the safe operation and high efficiency production of the shearer under different conditions,using the traction speed and cutting speed as the design variables,using the dynamic loads of gears,coal mining productivity,lump coal percentage as well as cutting energy consumption as the sub-goals,a multi-objective optimization model of cutting performance is established. Then,an optimization method for the weight coefficients selection of the different cutting performances is proposed based on the weight coefficients transformation,to determine the optimum weight combination for different conditions. Finally,the optimization calculation is conducted based on genetic optimization algorithm,and the optimal motion parameters with the change of cutting resistance are obtained under normal coal seam,gangue coal seam and rock fault condition. Besides,a comparative analysis of cutting performance of shearer based on the optimal motion parameters control and traditional traction speed control is conducted. Research results indicate that compared with the traditional traction speed control,not only the economic performance of shearer under normal coal seam and gangue coal seam is obviously improved,but also the fault zone can be cut through safely and rapidly by adopting the optimal motion parameters control;besides,the local resonance of cutting transmission system is appeared when the drum speed is 24 r/ min,hence it is necessary to avoid running at the resonant speed whenthe drum is variable-speed cutting. The obtained results lay a theoretical basis for the implementation of the adaptive variable speed cutting of drum shearer.