School of Environmental Science and Engineering, Tianjin University
School ofMechanical Engineering, Tianjin University of Commerce
CECEP Green CarbonEnvironment Protection

酒糟厌氧发酵是当前处理酒糟的有效手段,而基于水力碎浆机的酒糟分离技术在保证稻壳和发酵有机质分离的基础上,具有简化设备并降低能耗的优势。采用ANSYSFluent软件对水力碎浆机内部的酒糟-废水两相流动进行CFD模拟,从速度场、压力场、组分场及流线等方面详细研究了稻壳、有机质和废水的混合流动规律,并进行了稳态和瞬态的流场研究。模拟结果表明,水力碎浆机内转子顶部弯叶内侧的浆料可达到最大速度48.06m/s,并且沿径向逐渐向外衰减至接近于0;由于转子的高速旋转,其前后分别形成了高压区和低压区,最大工作压力为3.06×105Pa;浆液整体呈现离心运动,压力由中心向壁面递增,中心处转子周边由于流动形成极大负压,带动中心浆料向下运动,而壁面处压力最大,达0.125MPa;稳态计算下,水力碎浆机能实现良好混合,混合后浆料固相体积分数为5.72%~5.81%;转子下方的狭缝区域为盲区,此处固定相体积分数达最大值5.81%,因此,可适当提高转子的高度以改进水力碎浆机的性能;瞬态计算下,8min碎浆过程即可达到所需的混合效果。另外,总结了酒糟-废水混合流动规律,即来自顶部中心的酒糟主要是在重力作用下开始下降,随后在靠近水力碎浆机的区域被转子旋转带入左侧或右侧的漩涡区,从而与浆液良好地混合;而来自顶部侧边的酒糟在重力作用下降时,更快地参与了左右两侧的大漩涡运动。研究结果对于优化酒糟-废水制浆运行参数具有重要意义。

Anaerobic fermentation of distiller's grains (DG) is an effective method to treat DG. TheDG separation technology, based on a hydraulic pulper, simplifies equipment and reduces energyconsumption while ensuring the separation of rice husks and fermented organic matter. ANSYS Fluent,a widely used computational fluid dynamics (CFD) software, was used to simulate the two-phase flowof DG wastewater in the hydraulic pulper. The study focused on the mixed flow characteristics of riceEnergy Environmental Protectionhusk, organic matter, and wastewater, investigating the velocity field, pressure field, composition field,flow lines, as well as the steady-state and transient flow fields. The simulation results showed that theslurry inside the curved blade at the top of the rotor reached a maximum velocity of 48.06 m/s andgradually decreased to zero along the radial direction. Due to the rotor's high-speed rotation, a high-pressure zone and a low-pressure zone were formed on each side of the rotor, with a maximum workingpressure of 0.306 MPa. The slurry exhibited centrifugal movement, with the pressure increasing radiallyfrom the center towards the wall. The flow around the center formed a significant negative pressure,driving the central slurry downward. The highest pressure was at the wall, reaching 0.125 MPa. Aregion of low mixing efficiency was observed below the rotor, with the maximum solid concentrationreaching 5.81%. Therefore, adjusting the rotor's height in the hydraulic pulper could be beneficial.During transient calculations, the desired mixing effect was achieved within an 8-minute crushingprocess. The mixed flow process of DG and wastewater can be summarized as follows: DG from the topcenter fell under the action of gravity and was then rotated by the rotor near the water pulper into theleft or right vortex area, resulting in effective mixing with the slurry. DG from the top side quicklyjoined the swirling motion on both sides as they descended due to gravity. The results are important foroptimizing the operating parameter.

国家重点研发计划资助项目(2023YFC3905801);天津大学-中节能绿碳环保有限公司校企合作项目(2021GKF-0105)

颜蓓蓓,刘晓芸,周生权,等.面向厌氧发酵的酒糟-废水混合流动特性模拟研究[J].能源环境保护,2024,38(6):105−111.

YAN Beibei, LIU Xiaoyun, ZHOU Shengquan, et al. Simulation of mixed flow characteristics of distiller′sgrains-wastewater for anaerobic fermentation[J]. Energy Environmental Protection, 2024, 38(6): 105−111.