Efficient waste-to-energy system as a contribution to clean technologies

This paper deals with the problem of efficient energy utilization in the field of thermal processing of waste (waste-to-energy). An up-to-date incineration plant cannot be considered as only waste disposal facility. The waste combustion (incineration) processes are accompanied by release of large amount of energy, that shall be effectively utilized (e.g. steam production and its export to consumers, power generation, cogeneration). In addition to the main purpose of incineration, i.e. treating the specified amount of waste, waste-to-energy systems are able to some extent substitute conventional energy production plants fired by fossil fuel and thus to contribute to solving global environmental problems. For example, methodology presented in Reference Document on the Best Available Techniques for Waste Incineration (BREF) can be used for assessment of plant performance from the view of energy utilization. This approach is based on evaluation of criterion Plant Efficiency. An existing incineration plant has been evaluated and results are presented and discussed. In the future, it has been expected that evaluation like this will be obligatory for every plant. The arrival of more and more sweeping environmental limits represents a driving force for retrofit. At the same time maximum heat recovery and efficient energy utilization should be required. Influence of different operational modes (type of waste incinerated, combustion temperature, air-preheating etc.) and lay-out of heat recovery system (e.g. cogeneration) on plant performance has been investigated. A mathematical model based on combination of basic auxiliary operations and simple thermodynamic models of heat engines has been created with the aid of a specific computational tool. Its conception is based on both requirements and experience coming from industry. The most serious problem of effectively running incineration plants consists in economical utilization of energy produced. Examples of integration into existing energy systems are shown and discussed. An erratum to this article can be found at     

川气东送工程节能环保技术的创新与应用

针对川东北地区敏感脆弱的生态环境及含剧毒高酸天然气的资源禀赋,始终坚持并严格落实"环保优先"的工程建设指导思想,大力推行以"节能环保、绿色低碳"为主要特征的生态工程建设模式,将系统优化思想与节能环保技术创新相结合、清洁生产措施与严格监管相结合,在优化设计、清洁生产、环境监测全过程推进节能环保技术的创新与应用,杜绝了重特大环境污染和生态破坏事故的发生,最大限度减少了工程建设对原始生态环境和人文历史环境的影响,实现了污染物排放浓度、总量和环境质量达标,履行了将川气东送工程建设成"生态工程"、把普光气田建设成"绿色气田"、把川气东送管道建设成"绿色能源大走廊"的社会承诺。     

面向灰库清理的超大伸缩比机械臂结构设计与刚度优化

火电厂灰库内壁粉尘粘壁、板结、搭桥等现象严重影响火电机组的安全运营,因此须对灰库内壁积灰进行定期全域清理。针对现有灰库清理机器人作业区间有限及因机械臂伸缩比不足、刚度不大导致的清理效果不佳等问题,通过设计引入往复绳排驱动机构和多级嵌套箱型臂体,设计了大刚度、伸缩比为1∶7的机械臂整体结构,研制出一款面向灰库内壁全方位清理的高效作业机器人。基于机械臂级联臂体本征结构和内外耦合作用力系深度分析,结合Castigliano第二定理和线弹性原理,建立了在复杂交变载荷作用下变长度机械臂整体刚度模型。综合考虑在极端工况下机械臂应力分布特征,通过周期性拓扑优化低应力区各离散子域孔洞形状,提出了在严苛质量约束下机械臂全域刚度优化方法。机械臂性能仿真和测试实验表明：优化后机械臂质量大幅减小,且具备理想的伸缩区间和刚度特性;机械臂末端偏移量的测试值与仿真值存在一定偏差,系机械臂加工和装配误差所致。研究结果为灰库清理机器人的结构设计和刚度优化提供了重要参考。     

Three‐Layered Hollow Nanospheres Based Coatings with Ultrahigh‐Performance of Energy‐Saving,Antireflection, and Self‐Cleaning for Smart Windows

In this study, a well‐controlled interfacial engineering method for the synthesis of SiO₂/TiO₂/VO₂ three‐layered hollow nanospheres (TLHNs) and TLHNs‐based multifunctional coatings is reported. The as‐prepared coatings allow for an outstanding integration of thermochromism from the outer VO₂(M) layer, photocatalytic self‐cleaning capability from the middle TiO₂(A) layer, and antireflective property from internal SiO₂ HNs. The TLHNs coatings exhibit excellent optical performance with ultrahigh luminous transmittance (T_lum‐l = 74%) and an improved solar modulation ability (ΔT_sol = 12%). To the best knowledge, this integrated optical performance is the highest ever reported for TiO₂/VO₂‐based thermochromic coatings. An ingenious computation model is proposed, which allows the n_eff of nanostructured coatings to be rapidly obtained. The experimental and calculated results reveal that the unique three‐layered structure significantly reduces the refractive index (from 2.25 to 1.33 at 600 nm) and reflectance (Rave, from 22.3 to 5.3%) in the visible region as compared with dense coatings. Infrared thermal imaging characterization and self‐cleaning tests provide valid evidence of SiO₂/TiO₂/VO₂ TLHNs coatings' potential for energy‐saving and self‐cleaning smart windows. The exciting inexpensive and universal fabrication process for well‐defined structures may inspire various developments in processable and multifunctional devices.     

An optimal integrated lot sizing and maintenance strategy for multi-machines system with energy consumption

This paper proposes an integrated model for multi-machines dynamic lot sizing aiming to produce a single item, considering the energy consumption during the production horizon. The objective is to find, firstly, the optimal lot size as well as the number of machines that satisfy a random demand under given service level and secondly, maintenance plan depended to production planning to minimise the total production, energy and maintenance costs. In fact, the problem of energy consumption is one of the most evoked topics especially with the decision of many governments to reduce theirs (For example France is willing to reduce the total consumption by 20% by 2020). The keys of this study are to consider, firstly, the correlation between the forecasting of demand, the variation of the working machines as well as their production rates under energy constraint and secondly the correlation between the production cadences and the maintenance strategy of all machines.