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人字纹斜槽式水稻育秧播种排种器优化设计与试验 被引量:1
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作者 刘大为 秦锋 +3 位作者 王志鹏 谢方平 李旭 龚明 《沈阳农业大学学报》 北大核心 2025年第2期99-109,共11页
[目的]针对现有水稻育秧播种排种器作业效率较低、高速作业时存在播种均匀性差导致播种合格指数偏低等问题,难以满足当前南方地区早稻毯状苗常规稻育秧播种的农艺要求,为改善传统机械直槽式排种器在高速作业时用种量较大、排种器的脉动... [目的]针对现有水稻育秧播种排种器作业效率较低、高速作业时存在播种均匀性差导致播种合格指数偏低等问题,难以满足当前南方地区早稻毯状苗常规稻育秧播种的农艺要求,为改善传统机械直槽式排种器在高速作业时用种量较大、排种器的脉动效应导致秧盘内稻种分布不均等问题,研究设计了一种人字纹斜槽式水稻育秧播种排种器。[方法]使用SOLIDWORKS三维软件对该播种装置关键结构进行设计,采用力学分析法对排种器充种充种特性进行研究并分析计算了人字纹斜槽倾角的最优数值。以常规稻湘早籼32为试验材料,确定以播种装置的排种轮转速、秧盘输送速度、种箱开度为试验因素,以播种合格率及空格率为性能评价指标,开展单因素和三因素三水平响应面试验。[结果]各因素对评价指标播种合格率与空格率影响的主次顺序为排种轮转速、种箱开度和秧盘输送速度,获得各因素最优参数组合为:排种轮转速为22.3r∙min^(-1),秧盘输送速度0.37m∙s^(-1),种箱开度29.9mm,该条件下排种器播种合格率94.36%,播种空格率为1.67%。[结论]以湘早籼32、中早35和黄华占3种常规稻作为试验品种,对比改进前后排种器的播种性能,结果表明改进后的人字纹斜槽式排种器满足常规稻毯状苗撒播的技术要求,研究结果可为水稻机械化育秧播种排种器的优化设计提供参考。 展开更多
关键词 农业机械 水稻育秧播种 人字纹斜槽式 性能试验
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FCC coprocessing oil sands heavy gas oil and canola oil. 3. Some cracking characteristics 被引量:1
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作者 Siauw H.Ng Nicole E.Heshka +2 位作者 Ying Zheng Qiang Wei Fuchen Ding 《Green Energy & Environment》 SCIE CSCD 2019年第1期83-91,共9页
Coprocessing of bitumen-derived feeds and biomass through a fluid catalytic cracking(FCC) route has the potential to assist in the reduction of fuel and petroleum product carbon footprints while meeting government reg... Coprocessing of bitumen-derived feeds and biomass through a fluid catalytic cracking(FCC) route has the potential to assist in the reduction of fuel and petroleum product carbon footprints while meeting government regulatory requirements on renewable transportation fuels. This approach is desirable because green house gas(GHG) emissions for producing renewable biofuels are significantly lower than those for fossil fuels, and coprocessing can be executed using existing refining infrastructure to save capital cost. The present study investigates the specific FCC performances of pure heavy gas oil(HGO) derived from oil sands synthetic crude, and a mixture of 15 v% canola oil in HGO using a commercial equilibrium catalyst under typical FCC conditions. Cracking experiments were performed using a bench-scale Advanced Cracking Evaluation(ACE) unit at fixed weight hourly space velocity(WHSV) of 8 h^(-1), 490–530℃, and catalyst/oil ratios of 4–12 g/g. This work focuses on some cracking phenomena resulting from the presence of oxygen in the blendda lower heat requirement for cracking due to the exothermic water formation, which also entails lower hydrogen yield at a given severity. The distribution of feed oxygen in gaseous and liquid products, the mitigation in GHG emissions, and the technological and economical advantages of the coprocessing option are also discussed. 展开更多
关键词 FCC coprocessing microactivity test(mat) unit Four-lump KINETIC model Heat of formation of water VAPOUR Carbon FOOTPRINT reduction
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