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青贮玉米收获机碟盘式籽粒破碎装置仿真优化与试验 总被引：2，自引：0，他引：2
针对青贮玉米收获机玉米籽粒破碎效果差、破碎率低、影响青贮秸秆发酵与籽粒养分转化的问题,设计了适合青贮玉米籽粒破碎的碟盘式青贮玉米籽粒破碎试验台,对关键部件刀盘进行了参数化设计,基于DEM法对籽粒破碎过程进行了运动和力学分析,首先建立基于离散元法的玉米籽粒粘结颗粒模型;利用EDEM离散元仿真软件开展正交仿真试验优化,选取刀齿数、刀刃深度、破碎间隙和刀辊转速作为仿真试验因素,籽粒破碎率为试验考察指标,确定了最优组合参数,即刀齿数48、刀刃深度5mm、破碎间隙2mm、刀辊转速59r/s,在该条件下籽粒破碎率为90.35%,仿真试验与台架试验相对误差为3.36%;台架试验结束后,采用宾州筛对其筛分,物料可分为小型、标准、大型和未完全破碎型4种,占比分别为1.3∶6∶1.8∶0.9,与仿真试验结果一致。台架试验各指标满足行业标准,实现了对玉米籽粒的高破碎和高作业效率。 相似文献
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针对现有青贮全株玉米粉碎揉丝机存在秸秆丝化率低、籽粒破碎率低和喂料易堵塞等问题,设计了切揉组合式青贮玉米粉碎机,一次性完成秸秆喂入、压扁划丝、铡切、籽粒破碎和粉碎揉丝等工序。通过理论研究和数值分析,对本机的输送装置、喂入切断装置及破碎揉丝装置等关键部件进行解析和结构优化,确定了性能参数。试验结果表明:当本机主轴转速为2 900 r/min时,秸秆丝化率为96.4%,籽粒破碎率为93.2%,实际生产率为3 560 kg/h,未出明显现堵塞现象,各项指标均满足粉碎揉丝机的国家标准要求,为青贮全株玉米粉碎揉丝机的设计提供理论依据和技术保障。 相似文献
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玉米秸秆揉丝包膜青贮技术主要设备有玉米秸秆揉丝机、打捆机和包膜机。工艺流程为:秸秆存放-晾晒-机械揉搓-添加菌种-打捆压实-裹包存放。技术要点是:1.青贮原料。传统玉米秸秆青贮大多利用收穗后的秸秆直接去除杂物和根茎进行调制。而该技术则要求秸秆的含水率控制在45%～60%之间。玉米 相似文献
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青贮玉米饲料籽粒破碎试验台设计与试验 总被引：1，自引：1，他引：0
为研究青贮玉米籽粒破碎机理,采用理论计算、三维建模和性能试验相结合的方法,设计喂入速度、破碎辊转速和对辊间隙等参数可调的青贮玉米饲料籽粒破碎试验台,主要工作部件包括喂入碾压机构、切碎滚筒装置和对辊式籽粒破碎装置,可对全株青贮玉米一次性完成秸秆传送、喂入压平、切碎抛送和籽粒破碎等工作流程。试验结果表明:当喂入速度为2 m/s、上破碎辊主轴转速为2 600 r/min时,秸秆切碎长度为21.79 mm,切碎长度合格率为95.9%,籽粒破碎率为96.3%,各项指标均符合国家标准和行业标准要求,可为籽粒破碎装置的设计提供理论依据和技术参考。 相似文献
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针对设施蔬菜秸秆制取有机肥中塑料绳、薄膜等垃圾不易分离,且茄子杆、辣椒杆等秸秆不易实现大产量、低粒度粉碎这一现状,设计了一种设施蔬菜秸秆清塑揉搓机。该清塑揉搓机总体上采用卧式螺旋结构,转动滚筒上焊接螺旋排布的小拨齿,揉搓腔内水平排列揉搓齿,由驱动系统通过小拨齿与揉搓齿对物料进行揉搓;粒度达到要求的物料经筛网及皮带输送机输送,粒度不达标物料连同塑料绳等经大拨齿在滚筒末端抛射出去。在计算功率、确定转速等总体设计的基础上,通过试验,对滚筒结构、筛网大小及揉搓齿等主要零部件进行了结构改进。 相似文献
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青贮玉米饲料籽粒破碎装置仿真分析与试验 总被引：1，自引：0，他引：1
籽粒破碎技术是提高青贮玉米饲料品质的关键技术,也是制约青贮玉米饲料机械化装置的瓶颈。采用SW三维建模、离散元法和田间试验相结合的方法,探究全株玉米离散元模型,模拟籽粒破碎作业过程中破碎对辊与玉米秸秆、玉米籽粒相互作业的过程;并对破碎对辊进行力学分析,用全株玉米粘结接触模型对对辊间破碎过程进行仿真试验,最后通过田间试验验证仿真结果的真实性。旨在研究青贮玉米籽粒破碎装置中不同工作参数对其运行质量及籽粒破碎率的影响,提高破碎装置的效率,进一步优化其结构。结果表明:在秸秆、玉米芯及籽粒的压缩和剪切试验中,设定加载速度为4 mm/min,对辊间隙为2 mm时,玉米秸秆和玉米芯轴向压缩最大临界破裂载荷均近似为2 360 N,玉米籽粒则近似为48 N,玉米秸秆和玉米芯径向最大临界剪切力分别为625 N和840 N,玉米籽粒则为23 N,破碎率达到最大值96%,仿真结果与试验结果保持一致,表明本文建立的三维离散元模型可应用于仿真青贮玉米籽粒破碎装置工作过程中的破碎情况,试验结果满足玉米籽粒破碎质量要求,为进一步研究籽粒破碎机理,分析籽粒破碎的影响因素提供理论依据和技术支持。 相似文献
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基于离散元法的苎麻茎秆分离装置仿真优化与试验 总被引：2，自引：0，他引：2
《中国农机化学报》2017,(1)
以现有剥麻机的关键机构辊齿结构为研究对象,通过分析苎麻茎秆与辊齿结构之间相互作用,建立茎秆折断分离的动力学模型,得到了辊齿转速、剥麻辊齿数及啮合深度等因素与茎秆分离力关系的表达式。运用EDEM软件建立茎秆分离与辊齿相互作用的离散元模型,利用建立的虚拟模型为仿真平台,以脱骨量和剩皮量为评价标准,采用4因素5水平的正交试验方法,对辊齿结构的参数与茎秆分离效果仿真试验分析。仿真结果表明,其影响性大小顺序为压辊转速、啮合深度、剥麻辊转速、剥麻辊齿数,最佳工作参数组合为压辊转速150r/min、啮合深度12mm、剥麻辊转速800r/min、剥麻辊齿数20。根据正交试验的最佳参数组合进行台架验证试验,茎秆分离脱骨率为98.5%。该理论研究为苎麻茎秆分离机理提供一种新的研究方法,也为研制新型苎麻茎秆分离机械设备提供理论依据。 相似文献
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鉴于铡揉的青(干)玉米秸秆、麦秸等农作物秸秆及牧草物料适用于养殖牛羊牲畜及生物质能发电等领域,可有效推动粮改饲政策进一步实施,设计了一种青贮秸秆铡揉机。为此,提出了青贮秸秆铡揉机的设计方案,并对青贮秸秆铡揉机的输送喂入装置、铡揉装置及抛料装置进行优化设计,并通过试验数据计算得到青玉米秸秆的物料相对含水率平均值为55%,秸秆铡揉长度为1 060mm,秸秆破节率的平均值达91%,标准草长率为8 9%。设计的青贮秸秆铡揉机对于助推畜牧养殖业的产业化发展,提高畜牧养殖产品肉奶品质、避免秸秆资源浪费及减少环境污染具有重要的现实意义。 相似文献
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Overland water and salt flows in a set of rice paddies 总被引：1，自引：0，他引：1
E. Playn O. Prez-Coveta A. Martínez-Cob J. Herrero P. García-Navarro B. Latorre P. Brufau J. Garcs 《Agricultural Water Management》2008,95(6):645-658
Cultivation of paddy rice in semiarid areas of the world faces problems related to water scarcity. This paper aims at characterizing water use in a set of paddies located in the central Ebro basin of Spain using experimentation and computer simulation. A commercial field with six interconnected paddies, with a total area of 5.31 ha, was instrumented to measure discharge and water quality at the inflow and at the runoff outlet. The soil was classified as a Typic Calcixerept, and was characterized by a mild salinity (2.5 dS m−1) and an infiltration rate of 5.8 mm day−1. The evolution of flow depth at all paddies was recorded. Data from the 2002 rice-growing season was elaborated using a mass balance approach to estimate the infiltration rate and the evolution of discharge between paddies. Seasonal crop evapotranspiration, estimated with the surface renewal method, was 731 mm (5.1 mm day−1), very similar to that of other summer cereals grown in the area, like corn. The irrigation input was 1874 mm, deep percolation was 830 mm and surface runoff was 372 mm. Irrigation efficiency was estimated as 41%. The quality of surface runoff water was slightly degraded due to evapoconcentration and to the contact with the soil. During the period 2001–2003, the electrical conductivity of surface runoff water was 54% higher than that of irrigation water. However, the runoff water was suitable for irrigation. A mechanistic mass balance model of inter-paddy water flow permitted to conclude that improvements in irrigation efficiency cannot be easily obtained in the experimental conditions. Since deep percolation losses more than double surface runoff losses, a reduction in irrigation discharge would not have much room for efficiency improvement. Simulations also showed that rice irrigation performance was not negatively affected by the fluctuating inflow hydrograph. These hydrographs are typical of turnouts located at the tail end of tertiary irrigation ditches. In fact, these are the sites where rice has been historically cultivated in the study area, since local soils are often saline-sodic and can only grow paddy rice taking advantage of the low salinity of the irrigation water. The low infiltration rate characteristic of these saline-sodic soils (an experimental value of 3.2 mm day−1 was obtained) combined with a reduced irrigation discharge resulted in a simulated irrigation efficiency of 60%. Paddy rice irrigation efficiency can attain reasonable values in the local saline-sodic soils, where the infiltration rate is clearly smaller than the average daily rice evapotranspiration. 相似文献
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瓦房店市是我国重要的水果生产基地,在国内水果生产领域占有重要地位。随着水果市场化的不断深入,如何满足和适应国内外市场需求成为瓦房店市水果生产的关键问题。从瓦房店市水果生产实际出发,阐述了实施水果生产标准化的必要性,提出了发展水果生产标准化的具体措施。 相似文献
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对引进的谷子新品种金谷子耐旱TG118进行品种比较试验和多点试种。结果表明：该品种抗旱、耐瘠、适应性强,稳产、高产、抗病抗风抗倒伏强,品质优良,粮草兼用,种植简单,省工易管;一般产量在6000kg/hm2以上,比当地主栽品种增产20%以上。最高产量达9450kg/hm2,适于在辽西北地区推广应用。 相似文献
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对《种子法》存在问题的探讨 总被引：1，自引：0，他引：1
李鹏 《农业机械化与电气化》2011,(6):129-130
《种子法》是我国种植业第一部法律。自实施以来,为依法加强种子管理提供了有力的法律支撑,促进我国种子产业发生翻天覆地的变化。但随着依法管理工作的深入和种子产业的快速发展,《种子法》及配套规章的一些问题逐步显现出来。对《种子法》及配套规章存在的问题进行深入分析,对需要进一步补充的章节以及需要调整的内容进行深入探讨,以求更加完善和明确。 相似文献
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About 30 years have passed since the Government of Egypt embarked on implementing a series of large scale drainage projects. At present, about 3.8 million acres have been provided with drainage systems on the basis of systematic pre-drainage investigations and designs. The target is to provide drains in approximately 6.4 million acres in the Nile Valley and Delta.The implementation of the subsurface drainage system is carried out by the public sector and private contractors under direct supervision of governmental regional departments. The implementation process depends on many factors related to the drainage material, machinery, manpower, site requirements, farmers and organizations involved. Problems and constraints are sometimes challenging, however, the annual rate of implementation has gradually increased to 170,000 acre/year.This paper discusses the different aspects involved in the implementation process of drainage systems. The development in materials, machinery and construction technologies will be reviewed. Institutional and management factors are going to be also considered. 相似文献
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在新世纪,面对机遇和挑战,党的十六大把“社会更加和谐”作为全面建设更高水平的小康社会的一个重要目标。中国人素有社会和谐的理想;西方人自古也向往社会和谐;借鉴东西方两种和谐社会思想的经验、教训,构建社会主义和谐社会理论。 相似文献
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Gunter Wriedt Marijn van der Velde Alberto Aloe Fayçal Bouraoui 《Agricultural Water Management》2009,96(5):771-789
We present a pan-European irrigation map based on regional European statistics, a European land use map and a global irrigation map. The map provides spatial information on the distribution of irrigated areas per crop type which allows determining irrigated areas at the level of spatial modelling units. The map is a requirement for a European scale assessment of the impacts of irrigated agriculture on water resources based on spatially distributed modelling of crop growth and water balance. The irrigation map was compiled in a two step procedure. First, irrigated areas were distributed to potentially irrigated crops at a regional level (European statistical regions NUTS3), combining Farm Structure Survey (FSS) data on irrigated area, crop-specific irrigated area for crops whenever available, and total crop area. Second, crop-specific irrigated area was distributed within each statistical region based on the crop distribution given in our land use map. A global map of irrigated areas with a 5′ resolution was used to further constrain the distribution within each NUTS3 based on the density of irrigated areas. The constrained distribution of irrigated areas as taken from statistics to a high resolution dataset enables us to estimate irrigated areas for various spatial entities, including administrative, natural and artificial units, providing a reasonable input scenario for large-scale distributed modelling applications. The dataset bridges a gap between global datasets and detailed regional data on the distribution of irrigated areas and provides information for various assessments and modelling applications. 相似文献
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在介绍粉质仪和拉伸仪结构和原理的基础上,探讨了粉质曲线中吸水率、形成时间、稳定时间、弱化度和评价值等指标与面粉品质的关系,以及如何根据拉伸曲线中面团最大拉伸阻力、延伸度和拉伸曲线面积等指标来评价面团品质,并结合生产实际,概述了粉质仪和拉伸仪在面粉生产中的作用。 相似文献
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车辆ABS控制算法的研究及探讨 总被引：1，自引：0，他引：1
对现代汽车的ABS控制算法作了一些简单的介绍,同时指出了它们的一些缺陷,相应地提出了几种对ABS的其它控制方法并加以探讨,其中着重论述了ABS门限值控制算法中参考车速的确定方法和基于附着系数的控制算法。 相似文献