生物质电厂秸秆燃料收集范围优化分析

在微元分析法的基础上建立生物质电厂燃料收集运输模型,利用该模型建立秸秆收集运输费用函数关系式,通过求解得到秸秆收储点的最佳收集半径。结果表明:收储点的运输费用与收集半径的立方呈正比。另外,当在生物质电厂周围布置一圈秸秆收储点时,收储点的最佳收集半径为0.25R,需布置9个收储点;当在生物质电厂周围布置二圈秸秆收储点时,收储点的最佳收集半径为0.16R,共需布置26个秸秆收储点,即最外圈布置16个收储点,次外圈布置10个,上述两种情况均比不建立秸秆收储点时节省运输费用。     

秸秆能源化利用的供应模式研究

原料供应是制约秸秆能源化发展的关键因素之一。针对秸秆能源化利用中存在原料供应成本高的问题,文章分析了国内外秸秆能源化利用和原料供应方式,提出4种秸秆原料供应模式,并进行优缺点和经济性分析对比。研究结果表明:收集半径小于12 km时(秸秆可收集量小于3.6万t),模式1(田间晾晒后收集—农用车装载—能源利用)经济性最优,适合于年消耗原料小于2.5万t的应用方式;收集半径为12~26 km时(秸秆可收集量为3.6~17万t),模式3(田间移动式打捆—收储点储存—能源利用)经济性最优,适合于原料用量较大的应用方式;为保障原料供应的经济性,收集半径不宜超过26 km;秸秆供应成本中人工成本居首,其次是原料成本,然后是收集和运输燃油动力成本。     

农作物秸秆气化发电系统经济性分析

对农作物秸秆气化发电系统投产前的最佳秸秆收集半径进行了分析,得出了最佳秸秆收集半径与电厂运行费用、运输费用、单位耕地面积秸秆年产量、秸秆收集系数之间的关系.对影响发电系统经济性的因素进行了敏感性分析,认为发电效率和上网电价是影响发电系统经济性的主要因素.     

水电工程施工物料配送中心三维选址的能耗优化研究

水电工程施工道路具有突出的三维空间特性,施工物料供需点高差大形成的冗长路径势必加大施工物料运输能耗。以汽车运输为研究对象,分析了高差因素对物料运输能耗和物料配送中心布置的影响,结合多元线性回归模型及现场物料需求点分布情况找出优选的主干道运输路径,建立了三维选址模型,寻找物料配送中心的最优布置点,根据载货汽车运输燃料消耗量的计算规则及系数取值分析,计算出最优配送中心下的总燃料消耗量,实现了运输能耗的最优化。     

秸秆颗粒燃料应用于小型火力发电厂的经济性分析

秸秆的运输与贮存是影响秸秆发电经济效益的主要因素,根据我国农作物秸秆的特点与分布特性,对秸秆的收集范围、运输半径、颗粒燃料厂的建设规模等进行了优化,结果表明:在我国现有的发电补贴政策的支持下,对12MW的燃煤电站进行秸秆颗粒燃烧发电改造在经济上是可行的.     

地理信息系统在秸秆资源化利用中的应用

从地理信息系统(GIS)技术在秸秆资源化利用中的应用出发,分析了统计学模型与遥感模型在秸秆资源量预测中的优缺点,介绍了GIS技术在数据管理、资源量空间表达、区域收集分析、厂点优化选择方面的具体应用.提出建立秸秆利用评估系统,以期对秸秆资源综合利用提供科学解决途径和有效手段.     

北京市废弃木质材料回收逆向物流优化模型设计

将废弃木质材料作为资源再生循环利用,对于北京市发展低碳经济、建设生态环境具有重要现实意义。文章就北京市废弃木质材料回收管理问题,提出了包含处理厂、回收中心和初始收集点的三层逆向物流网络运筹学优化模型,运用Lingo软件结合实际算例验证了该模型的有效性。根据回收中心到处理厂和初始收集点所产生的运输费用以及各回收中心和处理厂的运营费用,选择出最优回收中心地址和最优化路径,可为北京市废弃木材回收管理提供一定的参考。     

基于能源与气候发展2050路径计算器的英国更多CCS和更多生物能源路径分析

介绍了英国能源与气候变化部公布的2050路径计算器及其4个路径,主要分析了第3个路径——更多碳捕获与收集(CCS)和更多生物能源,其中包括:提高将运输排放量转变为零的水平、降低家庭温度、更多地使用风能及增建生物发电站。最后指出了加速科技发展是实现低碳最好的方法,提出了生物发电厂技术和生物染料的共燃技术等是未来的研究方向。     

大容量锅炉尾部烟道空气动力场研究

阐述了北方农村秸秆高效利用技术研究的重要意义;对各种秸秆高效利用技术进行了分析,指出了它们推广应用的技术关键。秸秆固化成型技术在近期已经具备一定推广应用条件。秸秆成型燃料燃烧特性艮好,且便于储存和运输。秸秆成型加工可以作为秸秆燃料的预处理技术,为各种秸秆的高效利用技术特别是直接燃烧技术准备原料。秸秆成型机技术已有较大进步,进一步研究需要在降低能耗和提高成产率方面开展。     

秸秆直燃发电的生命周期评价

应用生命周期评价(LCA)方法,以秸秆直燃发电项目为研究对象,对秸秆的种植、运输、粉碎干燥和燃烧发电等4个过程进行了清单分析,并分别计算出4个过程的能耗及其对环境的影响.结果表明,每燃烧100kg秸秆发电,对环境的总影响负荷水稻秸为247.36毫人当量,小麦秸为268.74毫人当量,玉米秸为267.33毫人当量.秸秆直燃发电对环境影响主要为烟尘和灰尘,对局部地区的影响占据首位.以水稻秸秆为例,100kg水稻秸秆在直燃发电过程中整个系统共从环境吸收CO2167.60kg,向环境释放CO2164.24kg,由此看到,秸秆直燃发电项目在减少温室气体排放上能起积极作用.     

避洪转移中安置点分配及路径优选分析

为研究避洪转移中安置点分配及路径优选的分析方法,提出将多个可再分转移小组和多个安置点共同考虑的‘多对多’安置点分配及路径优选的新思路。该方法基于洪水风险图信息,结合ArcGIS路径分析,运用运筹学运输问题方法求解安置点分配及路径优选。实际分析表明该方法合理可行,可用于分配安置点和选择最佳路径。     

A GIS-based method for identifying the optimal location for a facility to convert forest biomass to biofuel

There is growing interest in the production of biofuels from woody biomass. Critical to the financial success of producing biofuel is identifying the optimal location for the facility. The location decision is especially important for woody biomass feedstock owing to the distributed nature of biomass and the significant costs associated with transportation. This study introduces a two-stage methodology to identify the best location for biofuel production based on multiple attributes. Stage I uses a Geographic Information System approach to identify feasible biofuel facility locations. The approach employs county boundaries, a county-based pulpwood distribution, a population census, city and village distributions, and railroad and state/federal road transportation networks. In Stage II, the preferred location is selected using a total transportation cost model. The methodology is applied to the Upper Peninsula of Michigan to locate a biofuel production facility. Through the application of the two-stage methodology, the best possible location for biofuel production was identified as the Village of L’anse in Baraga County. Also investigated are the sensitivity of transportation cost and the optimal site for biofuel production to changes in several key variables. These additional variables included fuel price, transportation distance, and pulpwood availability. By applying sensitivity analysis based on limited availability of feedstock, the City of Ishpeming emerged as another viable location for the production facility.     

A new model that using transfer stations for straw collection and transportation in the rural areas of China: A case of Jinghai,Tianjin

Obtaining sufficient raw material and controlling straw transportation costs are two critical factors in planning new straw utilization factories. So we develop a straw collection and transportation model using transfer stations and propose a method to calculate the corresponding transportation costs based on China's specific agricultural and rural transportation conditions in this paper. We also present a case study showing how to build a straw collection and transportation system for a planned straw-coal power plant. In this model, villages are the smallest collection units. Therefore, we consider both the uneven distribution of straw and the fact that, in China, straw is gathered within each village. The straw collection area is divided into a grid, in which each grid cell may be selected to build a transfer station within it. Building the appropriate number of transfer stations and optimizing their locations will help to reduce transportation costs. The difference between utilizing highways and rural roads for transportation is also considered. Transportation cost calculations and location optimization for each transfer station are carried out in ArcMap. This model can be used to help any facility requiring straw to obtain it steadily at a low transportation cost. This study also has important relevance to the location distribution of straw consumption factories.     

光伏组件清洁机器人真实地形的路径规划

针对传统环境下路径规划方法已无法满足真实地形方面实际应用的特点,提出基于Unity3D平台的三维虚拟太阳能发电站真实地形下的路径规划方法。首先通过卫星云图进行数据采集和真实环境地形构建,在此基础上结合三维引擎Unity3D平台,采用3ds MAX在地形上建立光伏组件三维模型,生成实际地图。利用加入跳点策略的改进A;算法进行路径寻优,实现了清洁移动机器人在三维可视化实际地图的路径规划和场景漫游。     

Designing optimal supply chains for anaerobic bio-digestion/energy generation complexes with distributed small farm feedstock sourcing

Anaerobic bio-digestion/energy generation (ABD/EG) complexes that use animal waste have become increasingly important as renewable energy sources and logistics considerations are essential as animal biomass is of costly transportation due to its high weight per unit of energy generated. To ensure overall economic viability it is necessary to take into account the supply chain network when designing such a complex for at least two main reasons. First, these complexes provide power from energy sources which otherwise would go to waste and a well-designed supply chain network will significantly lower long-term operating costs. Second, because they provide an outlet for farm manure (their feedstock), these complexes allow farmers to expand production capacity whenever environmentally sound animal waste disposal is an active constraint to operations. This paper presents a methodology to design a supply chain which maximizes contribution and minimizes gas loss in the commonly found configuration in which feedstock providers are numerous small farms without on-site bio-digestion units, i.e., a configuration in which in-natura biomass is transported from those small farms to supply a nearby ABD/EG complex serving the region. The paper details three layers of analysis for designing optimal animal waste supply for anaerobic bio-digestion, including model formulation and mathematical solution for each stage. The broadest layer in the methodology is the identification of the optimal ABD/EG complex positioning given farm locations and consequent biomass transportation costs. The middle layer is the specification of the optimal logistics and transportation system, including the prioritization of supplying farms. The operational layer includes scheduling optimal biomass collection from each farm to minimize biogas loss.     

光伏组件清洁机器人真实地形的路径规划

针对传统环境下路径规划方法已无法满足真实地形方面实际应用的特点,提出基于Unity3D平台的三维虚拟太阳能发电站真实地形下的路径规划方法。首先通过卫星云图进行数据采集和真实环境地形构建,在此基础上结合三维引擎Unity3D平台,采用3ds MAX在地形上建立光伏组件三维模型,生成实际地图。利用加入跳点策略的改进A;算法进行路径寻优,实现了清洁移动机器人在三维可视化实际地图的路径规划和场景漫游。     

Investigation of Ag-bulk/glassy-phase/Si heterostructures of printed Ag contacts on crystalline Si solar cells

The interface structure of screen-printed silver contacts on a crystalline silicon solar cell has been studied by transmission electron microscopy (TEM). TEM results confirmed that the glassy-phase plays an important role in contact properties. There are at least three different microstructures present in optimal fired contacts. The location where silver-bulk directly contacts silicon is observed through SEM, and this is actually a very thin glass layer in between. In addition, high-density silver embryos on silicon were found for samples fired optimally. The results presented in this study suggest that Ag-bulk/thin-glass-layer/Si contact is the most decisive path for current transportation.     

A framework to determine optimal offshore grid structures for wind power integration and power exchange

This paper presents a framework to find optimal offshore grid expansions using a transportation model of the power grid. The method extends the standard mixed‐integer linear programming approach to the solution of the transmission expansion planning problem to account for fluctuations in wind power generation and load; this makes the method especially suited to identify optimal transnational offshore high‐voltage direct current grid structures for the integration of large amounts of offshore wind power. The applicability of the method is demonstrated by a case study of the North Sea region. Copyright © 2011 John Wiley & Sons, Ltd.     

Interturn Fault Diagnosis in Induction Motors Using the Pendulous Oscillation Phenomenon

A robust interturn fault diagnostic approach based on the concept of magnetic field pendulous oscillation, which occurs in induction motors under faulty conditions, is introduced in this paper. This approach enables one to distinguish and classify an unbalanced voltage power supply and machine manufacturing/construction imperfections from an interturn fault. The experimental results for the two case studies of a set of 5-hp and 2-hp induction motors verify the validity of the proposed approach. Moreover, it can be concluded from the experimental results that if the circulating current level in the shorted loop increases beyond the phase current level, an interturn fault can be easily detected using the proposed approach even in the presence of the existence of motor manufacturing imperfection effects