中小型合成氨厂变换系统的工艺设计与节能

在某１００ｋｔ／ａ合成氨装置变换系统的工艺设计中,同时采用了多种节能措施。工业运行结果表明,节能效果显著。     

An energy systems engineering approach for the design and operation of microgrids in residential applications

A distributed energy system refers to an energy system where energy production is close to end use, typically relying on small-scale energy distributed technologies. It is a multi-input and multi-output energy system with substantial energy, economic and environmental benefits. However, distributed energy systems such as micro-grids in residential applications may not be able to produce the potential benefits due to lack of appropriate system configurations and suitable operation strategies. The optimal design, scheduling and control of such a complex system are of great importance towards their successful practical realization in real application studies. This paper presents a short review and an energy systems engineering approach to the modeling and optimization of micro-grids for residential applications, offering a clear vision of the latest research advances in this field. Challenges and prospects of the modeling and optimization of such distributed energy systems are also highlighted in this work.     

On the thermionic emission from nitrogen-doped diamond films with respect to energy conversion

Thermionic energy converters utilize thermal energy and efficiently transform it into more useful electrical energy. A key aspect in thermionic energy conversion is the emission of electrons at elevated temperatures, where the electron emitter is separated from the collector by a vacuum gap and a voltage is generated due to the temperature difference between the emitter and collector. In this study, nitrogen-doped diamond films with a negative electron affinity surface have been synthesized with plasma-assisted chemical vapor deposition, and the electron emission has been imaged using high-resolution electron emission microscopy. This study reports the measurement of a thermovoltage and current, i.e. energy conversion, at temperatures considerably less than 1000 °C.     

Sulfur doped nanocrystalline diamond films as field enhancement based thermionic emitters and their role in energy conversion

Sulfur doped nanocrystalline diamond films, like other nanostructured carbon films, exhibit electron emission characterized by a spatial non-uniformity of the field enhancement factor. While field emission effects are observed at room temperature, an increase in emitter temperature is accompanied by an amplified emission current with a simultaneous drop in the threshold field. At low extraction fields a fit of the emission current to the Richardson equation indicates a material work function of 2.5 eV. The Schottky formula describes thermionic emission at a moderate field and is utilized to determine the work function at an electric field of 0.8 V/μm with a value of 1.7 eV and a concurrently reduced Richardson constant. This significant difference in the work function of 2.5 and 1.7 eV for 0.5 and 0.8V/μm, respectively can be attributed to field enhancement effects.     

Synthesis of MXene and design the high-performance energy harvesting devices with multifunctional applications

MXene is a promising candidate in two-dimensional materials because of its novel and unique properties. It shows remarkable results in energy harvesting devices owing to the high conductivity, transparency, excellent absorbance, significant generation of photogenerated charge carriers and extensive charge storage capabilities. The MXene is successfully synthesized and used in energy harvesting devices in this study. The estimated performance of the MXene/based Schottky photovoltaics device is increased to 11.9%, much higher than the recently reported 2D-based solar cells. Further, the efficiency and stability are estimated using the different interfacial layers (SiO₂, Al₂O₃, and h-BN) and surface modification by controlling the recombination rate and Schottky barrier height. Besides, the MXene is used to design an electrode in the supercapattery emerges device. The highest value of specific capacity (755.7 Cg^-1) is estimated at a current density of 1.5 Ag^-1. Further, the supercapattery device is designed. A high value of specific capacity (197.7 Cg^-1) and energy density of 68.8 WhKg^?1 with an extraordinary power density of 1120 WKg^-1 is obtained at the current density of 0.8 Ag^-1. Further, the Coulomb efficiency (92%) and capacity retention (87%) is maintained after 1000 charging and discharging cycles. The astonishing results provide a unique platform to increase the performance of photovoltaic and energy storage devices using 2D MXene materials.     

能源化工产业节能减排新模式

简述了陕北地区能源化工产业的现状,详细介绍了延长石油实施多种资源综合利用及二氧化碳的捕获、利用与封存(CCUS)产业的发展情况,重点介绍了靖边项目在提高资源利用率和节能减排方面的优势。对能源化工产业节能减排新模式进行了探索,走经济建设和环境保护协调发展的产业道路。     

给水管网GIS和水力模型无缝连接的方法研究

在如何利用给水管网信息管理系统(GIS)中的信息建立水力模型的研究中,传统方法容易导致水力模型继承GIS中的数据缺陷和错误,也不能保持模型和GIS系统的同步更新。文章提出建立共享数据库的方法,解决了此类问题,实现了给水管网GIS和水力模型之间的无缝连接。同传统方法相比,建模结果更准确,而且减少了重复开发、节约了项目投资。     

水力旋流器能耗机制与节能原理研究 Ⅴ.流场结构与能量耗损

采用正交试验设计,系统地研究了水力旋流器流场结构对其能量耗损的影响。结果表明,在水力旋流器结构中,中心插入部件结构对能量耗损影响最大,而底流管结构的影响最小;在中心插入部件中,中心翅片节能效果最佳。最后优化出了可使能耗系数最小的水力旋流器优化结构组合。     

Flexible design‐planning of supply chain networks

Nowadays market competition is essentially associated to supply chain (SC) improvement. Therefore, the locus of value creation has shifted to the chain network. The strategic decision of determining the optimal SC network structure plays a vital role in the later optimization of SC operations. This work focuses on the design and retrofit of SCs. Traditional approaches available in literature addressing this problem usually utilize as departing point a rigid predefined network structure which may restrict the opportunities of adding business value. Instead, a novel flexible formulation approach which translates a recipe representation to the SC environment is proposed to solve the challenging design‐planning problem of SC networks. The resulting mixed integer linear programming model is aimed to achieve the best NPV as key performance metric. The potential of the presented approach is highlighted through illustrative examples of increasing complexity, where results of traditional rigid approaches and those offered by the flexible framework are compared. The implications of exploiting this potential flexibility to improve the SC performance are highlighted and are the subject of our further research work. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

低供热源变压再生脱碳新工艺的开发及应用

开发了一种低供热源变压再生脱碳新工艺 ,并为该工艺研制了一套过程模拟计算和调优软件。在脱碳溶液再生系统 ,采用由加压再生塔、常压再生塔、贫液闪蒸槽以及亚音速喷射器组成的双塔变压再生流程 ,充分利用变换气带入的热量 ,使再生热耗显著降低     

我国粮食干燥节能途径

能耗是衡量粮食干燥机技术性能好差的一项经济指标。介绍了粮食干燥能耗情况，分析了粮食干燥的节能途径，供设计粮食干燥机时合理选用。     

Optimal design and operations of supply chain networks for water management in shale gas production: MILFP model and algorithms for the water‐energy nexus

The optimal design and operations of water supply chain networks for shale gas production is addressed. A mixed‐integer linear fractional programming (MILFP) model is developed with the objective to maximize profit per unit freshwater consumption, such that both economic performance and water‐use efficiency are optimized. The model simultaneously accounts for the design and operational decisions for freshwater source selection, multiple transportation modes, and water management options. Water management options include disposal, commercial centralized wastewater treatment, and onsite treatment (filtration, lime softening, thermal distillation). To globally optimize the resulting MILFP problem efficiently, three tailored solution algorithms are presented: a parametric approach, a reformulation‐linearization method, and a novel Branch‐and‐Bound and Charnes–Cooper transformation method. The proposed models and algorithms are illustrated through two case studies based on Marcellus shale play, in which onsite treatment shows its superiority in improving freshwater conservancy, maintaining a stable water flow, and reducing transportation burden. © 2014 American Institute of Chemical Engineers AIChE J, 61: 1184–1208, 2015     

The effect of gas pressure on NO conversion energy efficiency in nonthermal nitrogen plasma

This work explores the effect of gas pressure on the rate of electron collision reactions and energy consumption for NO conversion in N₂ in a pulsed corona discharge reactor. A previous study showed that the rate constant of electron collision reactions, multiplied by the electron concentration, can be expressed as . The model parameter α remains constant with increasing gas pressure, which verifies the previous assumption that the electron temperature is inversely proportional to gas pressure. However, the model parameter β decreases with increasing gas pressure, which indicates that the rate constant of electron collision reactions decreases with increasing gas pressure. The new expression for the rate constant of electron collision reactions, , is more general because it explicitly accounts for the effect of gas pressure that was previously contained in the parameter β. The electron mean energy decreases with increasing gas pressure, which results in thermal dissipation of a larger fraction of the energy input to the reactor that heats the gas instead of producing plasma chemical reactions. Therefore, energy efficiency for NO conversion in N₂ decreases with increasing gas pressure.     

Nationwide energy supply chain analysis for hybrid feedstock processes with significant CO2 emissions reduction

Integrating diverse energy sources to produce cost‐competitive fuels requires efficient resource management. An optimization framework is proposed for a nationwide energy supply chain network using hybrid coal, biomass, and natural gas to liquids (CBGTL) facilities, which are individually optimized with simultaneous heat, power, and water integration using 162 distinct combinations of feedstock types, capacities, and carbon conversion levels. The model integrates the upstream and downstream operations of the facilities, incorporating the delivery of feedstocks, fuel products, electricity supply, water, and CO₂ sequestration, with their geographical distributions. Quantitative economic trade‐offs are established between supply chain configurations that (a) replace petroleum‐based fuels by 100%, 75%, and 50% and (b) utilize the current energy infrastructures. Results suggest that cost‐competitive fuels for the US transportation sector can be produced using domestically available coal, natural gas, and sustainably harvested biomass via an optimal network of CBGTL plants with significant GHG emissions reduction from petroleum‐based processes. © 2012 American Institute of Chemical Engineers AIChE J, 2012     

Integration and management of renewables into Total Sites with variable supply and demand

Reducing CO₂ emissions could be achieved by maximising heat recovery and increasing the share of renewables in the primary energy mix. Process Integration has developed over the years into a credible process system engineering tool. One of its important developments has been Total Site Heat Integration, which has combined the heating and cooling requirements of individual processes unlocking, allowing better integration. The current paper presents an extension of the Total Site methodology covering industrial, residential, service, business and agricultural customers and the incorporation of renewable energy sources (solar, wind, biomass, and some types of waste), accounting for the often substantial variability on the supply and demand sides and for the use of non-isothermal utilities. It further applies the extension of the heat cascade principle with inclusion of heat storage and minimises the heat waste and carbon footprint of the considered sites. This is illustrated with a comprehensive case study.     

中国水泥工业能效现况和节能潜力报告

从水泥产量、规模结构、技术结构和产品结构来看,我国水泥工业大而不强,其能效现状说明还有很大的节能潜力可挖。其途径有:(1)积极发展新型干法窑,淘汰能耗大、技术落后的其它工艺; (2)提高熟料质量和混合材的掺加量; (3)大力推广高强度混凝土和高性能混凝土; (4)利用工业废渣和二次燃料; (5)发展余热发电……这些节能措施的经济效果是令人振奋的,仅“以质代量”所产生的经济效益就达270亿元(以2002年水泥产量7.25亿t计算)。     

Investigation of the effect of the structure of large-area carbon nanotube/fuel composites on energy generation from thermopower waves

Thermopower waves are a recently developed energy conversion concept utilizing dynamic temperature and chemical potential gradients to harvest electrical energy while the combustion wave propagates along the hybrid layers of nanomaterials and chemical fuels. The intrinsic properties of the core nanomaterials and chemical fuels in the hybrid composites can broadly affect the energy generation, as well as the combustion process, of thermopower waves. So far, most research has focused on the application of new core nanomaterials to enhance energy generation. In this study, we demonstrate that the alignment of core nanomaterials can significantly influence a number of aspects of the thermopower waves, while the nanomaterials involved are identical carbon nanotubes (CNTs). Diversely structured, large-area CNT/fuel composites of one-dimensional aligned CNT arrays (1D CNT arrays), randomly oriented CNT films (2D CNT films), and randomly aggregated bulk CNT clusters (3D CNT clusters) were fabricated to evaluate the energy generation, as well as the propagation of the thermal wave, from thermopower waves. The more the core nanostructures were aligned, the less inversion of temperature gradients and the less cross-propagation of multiple thermopower waves occurred. These characteristics of the aligned structures prevented the cancellation of charge carrier movements among the core nanomaterials and produced the relative enhancement of the energy generation and the specific power with a single-polarity voltage signal. Understanding this effect of structure on energy generation from thermopower waves can help in the design of optimized hybrid composites of nanomaterials and fuels, especially designs based on the internal alignment of the materials. More generally, we believe that this work provides clues to the process of chemical to thermal to electrical energy conversion inside/outside hybrid nanostructured materials.     

Agent-based supply chain management—2: a refinery application

The refinery business involves tasks that span several departments and process large amount of data. Among others, these include crude procurement, logistics and scheduling (storage, distillation units, etc.). Current refinery decision support systems (DSSs) fail to integrate all the decision-making processes of a refinery, to interface with other systems in place, to incorporate dynamic data from various sources and to assist different departments concurrently. In part 1 of this two-part paper, we proposed an agent-based framework for supply chain DSSs. Here, we demonstrate its application through a prototype DSS, called petroleum refinery integrated supply chain modeler and simulator or PRISMS, for crude procurement. PRISMS serves as a central DSS through which all processes of a refinery can be studied and enables integrated decisions with respect to the overall refinery business. In particular, PRISMS can be used to study the effects of internal policies of the refinery and its various departments. We illustrate this through three detailed ‘what-if’ studies that provide an insight into how the business responds to changes in policies, exogenous events and plant modifications.     

给水中的致味物质及其检测方法

水中化学性或生物性致味物质是给水异味产生的来源,这些痕量异味物质的存在严重影响了给水的品质,因此给水中致味物质的富集、定性定量分析及去除等相关研究是近年来全世界都关注的一个重要课题。作者介绍了给水异味物质的分类与来源,阐述了国内外给水异味物质的感官及仪器检测方法,总结了国内外给水异味研究方面的差异,指出了CLSA—GC与SDE—GC互补使用是给水异味分析的最精确有效的手段。