关键词: 秸秆发酵, 螺旋搅拌结构, 离散单元法, 变异系数, 参数优化

Abstract: Aiming at the problem of unequal mixing of crushed materials and strains in the process of straw fermentation, the parameters of spiral stirring structure of aerobic reactor were optimized. Based on the discrete unit method in the material theory and simulation analysis, the result showed that the primary and secondary order of the influence coefficient of variation was rotational speed, pitch ratio and leaf width ratio. With the increase of stirring leaf width ratio, the value of coefficient of variation was decreased and then increased, and the average power was decreased; with the increase of stirring pitch ratio, the value of coefficient of variation was decreased and then risen, and the average power was fallen; with the increase of stirring rotational speed, the mixing coefficient was fallen, and the average power was increased and then decreased. The coefficient of variation model was constructed and optimized, and the optimal mixing coefficient was 13.295%, and the error with the simulation result was 1.411%. The stirring device was analyzed statically, and the maximum stress value was 47.259 MPa, and the maximum deflection was 4.357 5 mm. The average error between discrete element simulation power and test value was 14.1%, which was in accordance with the design requirements. This stirring device design can provide theoretical support for efficient mixing of fermentation reactor.

Key words:  straw fermentation, spiral stirring structure, discrete element method, coefficient of variation, parameter optimization