生物质流化床气化与结渣特性中试试验     

廖新杰  张世红  李姜昊  罗俊伟  杨文海  张雄  陈汉平 《农业工程学报》2021,37(4):235-241

为优化生物质流化床气化工艺,该研究在中试规模流化床实验台上进行了成型树皮和成型秸秆的空气气化试验,研究了空气当量比、气化温度与送风温度对成型树皮和成型玉米秸秆气化特性的影响,同时采用电子探针显微分析仪与X射线光谱分析仪对气化过程中结渣的微观结构与成分进行了分析。结果表明:气化效果随着空气当量比增大先升后降,空气当量比较佳值在0.24左右,此工况下树皮与秸秆合成气热值分别为5.66和3.92 MJ/m~3,气化效率分别为59.62%与33.92%;气化温度增加促进气化效果提升,气化温度从700℃升高至800℃,树皮合成气热值与气化效率分别提升了1.01 MJ/m~3与14.28%;一次风温度的提升对气化效果无显著影响(P0.05),但明显提升了炉膛底部温度,容易导致结渣,不利于设备稳定运行。2种生物质都有明显结渣现象,其表面呈现熔融玻璃状。结渣主要由KAl(SiO3)、K2MgSi_5O_(12)等复杂化合物与SiO_2组成。导致结渣的原因主要是生物质中K、Mg等碱金属元素在床料中富集,与石英砂床料反应形成低熔点熔融盐;树皮含有较多Ca,气化中形成高熔点的CaSO_4进而抑制结渣,而秸秆成灰率高,含有较多的K,导致结渣更为严重。  相似文献   

基于CFD的养殖污水净化内循环流化床反应器结构优化     

李源  杨菁  管崇武  宋红桥  吴凡  张成林  陈晓龙 《农业工程学报》2014,30(22):44-52

针对水产养殖污水净化对内循环流化床反应器的相关要求及流化状态下反应器结构、操作参数与相流体力学行为的密切关系,该文利用构建的描述不同结构、操作参数反应器气液两相流动的计算流体力学数学模型,分析了不同结构、操作参数下反应器液体流场、液体循环流量、气含率的变化规律,得到了对于内径200 mm、底部采用均孔布气盘的反应器,在表观气速为0.5~2.5 cm/s时,导流筒与反应器的内径比0.5,导流筒高度与反应器内径比6,导流筒下端到反应器底部距离50 mm,导流筒上端到液面距离100 mm为最优值;针对液体循环流量,使用相关数学模型求解理论值并与试验值进行比对,通过偏差分析探究了数学模型应用的局限性;使用MATLAB最小二乘法拟合了反应器在最优结构参数下表观气速与液体循环流量、气含率的关系,验证了拟合公式的精确性。该研究为内循环流化床反应器在水产养殖污水处理中的设计应用提供理论和技术参考。  相似文献   

AM真菌对田间山银花生长、矿质营养及绿原酸含量的影响     

SHI An-Dong  LI Qian  HUANG Jian-Guo  YUAN Ling 《土壤圈》2013,23(3):333-339

Lonicera confusa, a traditional Chinese medicine herb for treating cold, flu, acute fever, and so forth, is often grown artificially in acidic soils and suffers from phosphorus (P) deficiency. A five-year field experiment was carried out to study the colonization rate, growth, nutrition, and chlorogenic acid content of Lonicera confusa seedlings inoculated with arbuscular mycorrhizal (AM) fungi, Glomus etunicatum and Glomus intraradices. Before transplanting into a field, both AM-inoculated and uninoculated control plants were cultured in nursery beds. In the plants inoculated with the AM fungi, the colonization rate decreased linearly with time and a greater decrease was observed in the plants inoculated with G. intraradices than with G. etunicatum, while the AM colonization increased from 0% to 12.1% in the uninoculated control plants 5 years after transplanting. Plant height, crown diameter, number of new branches, and flower yield increased significantly by AM inoculation as compared to the uninoculated control. Phosphorus concentrations in leaves and flowers increased, and plant uptake of nutrients, e.g., nitrogen (N), P, and potassium (K), was also enhanced significantly by AM inoculation. The Lonicera confusa seedlings had a better response to inoculation of G. intraradices than G. etunicatum in both growth and chlorogenic acid content in flowers. In contrast, both plant P uptake and P concentrations in leaves and flowers were similar between two fungal inoculations. The positive responses of Lonicera confusa to AM inoculation in growth, nutrient uptake, flowering, and chlorogenic acid content in flowers suggested that AM inoculation in nursery beds could promote the plant growth and increase chlorogenic acid content in flowers of Lonicera confusa when grown on acidic and P-deficient soils.  相似文献   

升温方式对中试鼓泡流化床气化过程的影响     

李晓伟  刘建坤  王贵路  李明鹤  郑磊  叶仁文  张大雷 《农业工程学报》2015,31(5):275-279

为了研究中试鼓泡流化床升温过程特性,试验以木屑为原料,处理量50kg/h的自供热中试鼓泡流化床为反应装置,采取3种不同的升温方式进行空气气化试验研究。升温过程分别采用木屑、木屑与木炭混合、木炭为加热原料,针对气化前期系统升温过程中的气化温度、焦油含量、气体品质及最小流化速度进行了研究。结果表明:采用纯木炭的升温方式效果较为理想;气化主反应区温度控制在900℃以上,温度及升温速率的提高有利于减少焦油生成量,实测焦油含量为1.15g/m3;空气气化时热值可达6.9MJ/m3;最小流化速度受床料粒径和升温速率影响。该试验可为自供热中试流化床试验平台的升温方式提供一种设备简单,操作方便、快捷,经济性好的新方法。  相似文献   

混合浮床对南海湖湿地富营养化水体修复的作用     

王志超  王智超  缪晨霄  杨文焕  于玲红  张明钰  宋嘉乐  李卫平 《水土保持通报》2019,39(4):120-126,133

[目的]探究植物的交互作用对生态浮床去除N,P效率的影响,为后期南海湖湿地规模化建设提供理论依据。[方法]在自然开放水域条件下,选取适合于北方生长的3种挺水植物水葱、千屈菜、风车草为浮床植物,以高密聚乙烯空心塑料基盘为植物载体,建立单一种植与交叉混合种植两种浮床体系,在南海湖湿地保护区进行为期90 d的水质处理,研究植物生长特性及浮床净化效果。[结果] 10月份收割时,混合浮床中水葱和风车草的分蘖数分别达26和30株,生物量(鲜重)分别为1.43和1.98 kg/株。风车草浮床N累积量最好,达110.6 g/m~2,水体TN去除率34.9%。混合浮床P累积量最好,达26.02 g/m~2,水体TP去除率43.3%。[结论]植物的交互作用对植株的分蘖繁殖有一定促进作用,但不改变植物自身N,P吸收能力,植物体对N,P的累积量受生物量影响较大,3种植物在混合浮床中的整株N,P累积量要高于单植物浮床,混合浮床可作为针对南海湖富营养化水体修复的浮床形式推广使用。  相似文献   

循环流化床中塑料粉与稻壳共燃生成NO的研究     

伍昌鸿  马晓茜  董志强  赵增立  李海滨  陈勇 《农业机械学报》2007,38(1):92-95

为研究塑料与稻壳共燃的氮氧化物生成规律，在自行设计的循环流化床装置上进行了二者的共燃实验。研究了温度、塑料粉和稻壳的混合比例及过量空气系数对NO生成量的影响。实验结果表明，随温度升高，NO生成量升高；随塑料粉与稻壳混合比例增加，NO生成量呈降低趋势，且NO的生成量低于二者单独焚烧时生成量的线性叠加；随着过量空气系数增加，NO生成量降低。为寻找二者共燃NO生成的一般性规律，采用径向基神经网络建立了NO生成的预测模型，预测结果显示该模型具有很高的精度。  相似文献   

基于高光谱联合流化床富集的红葡萄酒白藜芦醇检测     

刘贵珊  房盟盟  冯愈钦  郭红艳  何建国 《农业机械学报》2017,48(7):301-308

利用高光谱成像技术联合流化床富集技术对红葡萄酒中微量成分白藜芦醇的含量进行快速检测。通过高效液相色谱法检测红葡萄酒中白藜芦醇的含量,设计流化床富集装置,研究HPD826、DA-201、AB-8、H103、HPD600共5种树脂对红葡萄酒中白藜芦醇的富集效果,筛选出H103树脂富集效果最优。将H103大孔吸附树脂用于富集红葡萄酒中的白藜芦醇。获取吸附白藜芦醇后树脂的高光谱反射图像(900~1 700 nm),对比5种光谱预处理方法(MSC、SNV、SG-S、RN、QN)对白藜芦醇含量的建模效果,优选出RN预处理方法;建立PLSR、SVMR(LK-SVMR、PKSVMR、RBF-SVMR和S-SVMR)、PCR的6种回归模型,优选出LK-SVMR校正模型和PLSR校正模型,将其用于预测集样本进一步评价模型的精度和稳定性,最终确定PLSR模型为最佳模型。研究表明,基于RN-PLSR的红葡萄酒中白藜芦醇的定量预测模型相关系数R_P=0.852 8,预测集均方根误差为0.036 0,R_C=0.878 3,校正集均方根误差为0.033 0,预测效果最佳,为高光谱技术在微量、痕量成分检测方面的应用提供了参考。  相似文献   

枸杞岛海藻场大型底栖无脊椎动物摄食类群研究   总被引：1，自引：1，他引：1  

吴祖立  章守宇  陈彦  毕远新 《水产学报》2015,39(3):381-391

随着海洋生态学研究的深入和海洋环境监测的需要,一些传统的研究方法如多样性指数等在评价大型底栖生物群落结构变化时显得说服力不足,而摄食功能群的研究越来越受到重视。本实验根据2012年8月对浙江枸杞岛海藻场大型底栖无脊椎动物的调查实验,分析该海域夏季大型底栖无脊椎动物摄食类群的组成、空间及数量分布,并进行相关生态评价。结果表明,枸杞岛海藻场夏季大型底栖无脊椎动物组成以肉食者和滤食者占较大优势,食碎屑者、植食者和食底泥者次之,杂食者最少;肉食者的优势种为布尔小笔螺、寄居蟹、扁平管帽螺、甲虫螺和四齿矶蟹等,滤食者的优势种为条纹隔贻贝、带偏顶蛤、短石蛏和布氏蚶等,植食者的优势种为钩虾、单一丽口螺和锈凹螺等;各摄食类群水平分布较均匀,垂直分布受水深和摄食饵料的限制;基于大型底栖无脊椎动物功能类群的生态参数评价结果表明,枸杞岛海藻场大型底栖无脊椎动物群落健康状态呈虚弱水平,大部分站位大型底栖无脊椎动物群落受到轻度扰动,底栖生态质量状况较好。  相似文献   

Effects of leaf area and auxin on rooting and growth of rooted stem cuttings of neem     

M. Kamaluddin  M. Ali 《New Forests》1996,12(1):11-18

Green stem cuttings, obtained from 2-year old managed stockplants, with 30, 50 or 100% leaf area were rooted in a non-mist propagator following treatment with 0, 0.2, 0.4 or 0.8% IBA solution. The rooted cuttings were transferred to polythene pots and grown in a nursery for 12 weeks. Rooting percentages of IBA treated cuttings did not significantly differ from those of control cuttings. Likewise leaf area did not significantly influence the percentage of cuttings that rooted. The effects of leaf area and/or IBA treatment in the propagation unit were manifested on the growth of rooted cuttings in polythene pots. Number of roots increased with the increase in IBA concentration and this response was enhanced by increasing leaf area. Root biomass increased with the increase in leaf area even in the control cuttings. Root development was highly influenced by the leaf area and IBA, and hence the growth of rooted cuttings. Cuttings treated with 0.2 or 0.4% IBA at 100% leaf area yielded the best performing rooted cuttings.  相似文献   

Effects of crop establishment techniques on weeds and rice yield     

《Crop Protection》2014

Field and pot studies were conducted to evaluate the effects of seven rice establishment techniques {puddling transplanting (PT), no tillage transplanting (NTT), puddling drum wet seeding (PDWS), no tillage drum wet seeding (NTDWS), conventional tillage dry drilling (CTDD), furrow irrigated raised beds system dry drilling (FIRBSDD), and no-tillage dry-drilling (NTDD)} and water submergence stress on weeds and rice yield. The highest yield and least weed abundance were in the PT treatment. The direct seeded rice (DSR), both dry and wet exhibited severe weed infestation, and compared to transplanting showed reduced yield both in the presence and absence of weeds. The yield losses due to weeds in the DSR treatments ranged from 91.4 to 99.0%, compared to 16.0 and 42.0% in the transplanting treatments (PT and NTT). Weeds, including Cyperus rotundus L., Dactyloctenium aegyptium (L.) Willd., Digera arvensis Forsk., Phyllanthus niruri L., and Trianthema portulacastrum L. which were found in the un-puddled DSR treatments were absent in the puddled plots, particularly the PT treatments. In pot studies, continuous water-submergence (2.5 cm) for 20 days reduced the emergence of C. rotundus, D. aegyptium, T. portulacastrum, and Echinochloa crus-galli (L.) Beauv. by 99.4, 100, 100, and 24.4%, respectively, compared to alternate wetting–drying. In farmer's field studies, when compared to the PT treatments, the DSR treatments exhibited lower yields (15.8%) with coarse varieties (HKR-47 & IR-64), but fine cultivars (Sharbati & PB-1) exhibited similar yields under both systems. In view of the shortage of labour for manual transplanting, there is a need to develop suitable cultivars for aerobic system conditions (unpuddled DSR and NT machine-transplanting).  相似文献