Microscale combustion: Technology development and fundamental research

The high energy density of hydrocarbon fuels creates a great opportunity to develop combustion based micro-power generation systems to meet increasing demands for portable power devices, micro unmanned aerial vehicles, micro-satellite thrusters, and micro chemical reactors and sensors. In this paper, the recent technological development of micro-power systems and progress in fundamental understanding of micro-scale combustion are reviewed. At first, micro-scale combustion regimes are categorized by using different physical and chemical length and time scales and the resulting non-dimensional parameters and their correlations to various combustion regimes for micro and mesoscale combustion are discussed. Secondly, the recent successful developments and technical challenges of micro-thrusters, micro internal combustion engines, and micro chemical reactors summarized. Thirdly, the underlying fundamental mechanisms and ignition and flame dynamics in micro-scale combustion are reviewed, respectively, in premixed, non-premixed, catalytic, and non-equilibrium, micro-scale combustion systems. The conventional concepts of combustion limits such as the flammability limit, quenching diameter, and flame extinction and heat recirculation are revisited. The unique thermal and chemical transport mechanisms such as flame structure interaction, radical quenching, non-equilibrium transport appearing in micro-scale combustion are discussed. New flame regimes and instabilities such as flame bifurcation, weak flames, flame cells/streets, thermal and kinetic quenching, flameless low temperature catalytic combustion, repetitive extinction and ignition, spinning flames, spiral and multi-branched flames, symmetric and asymmetric oscillating flames are discussed. Finally, an overview of future research and conclusion are made. The goal of this review is to present an overview of the development of micro-power generators by focusing more on the advance in fundamental understanding of micro-scale combustion.     

山水气林田湖草城系统治理工程技术研究

本文对“山水气林田湖草城”系统治理的理论与工程技术进行了全面深入地研究.提出了修复山形地貌、净化水体质量、调节大气成分、优化森林结构、改良农田土质、重建湖域生态、扩大种草面积、完善城市规划的方法.对“山水气林田湖草城”进行整体保护、系统恢复、综合治理;量化生态资源的隐性价值;发展新气候经济;实施碳热氧产品交易;设立碳热氧税制度;建立经济生产总值与生态生产总值平衡发展体系;创建零碳模式;使人与植物、动物、微生物和自然环境之间,生物各个种群之间,生态诸子系统之间,通过能量流动、物质循环和信息传递达到高度适应、协调和统一的平衡状态,减弱减少自然灾害,延长人类在地球上的生存时间.     

能源互联网共享运营平台关键技术及应用

能源互联网是充分利用云大物移智链等先进IT技术,整合数据资源,贯通产业链上下游,实现能源电力全过程的精益管理、高效运行、共享服务。文章从能源互联网对外共享和运营的业务痛点出发,详细设计了运营服务平台的业务架构、应用架构、技术架构和数据架构,并研究了共享运营平台的多源异构数据处理与存储、海量异构数据统一计算、敏捷开发和自动化部署等关键技术,通过整合营销、调度、配电等内部数据以及经济、环境、政策等外部数据,支撑用电数据的深度挖掘和增值服务,最后设计了面向工业用户的典型应用场景。     

Biofuels and biochemicals production from forest biomass in Western Canada

Biomass can be used for the production of fuels, and chemicals with reduced life cycle (greenhouse gas) emissions. Currently, these fuels and chemicals are produced mainly from natural gas and other fossil fuels. In Western Canada, forest residue biomass is gasified for the production of syngas which is further synthesized to produce different fuels and chemicals. Two types of gasifiers: the atmospheric pressure gasifier (commercially known as SilvaGas) and the pressurized gasifier (commercially known as RENUGAS) are considered for syngas production. The production costs of methanol, (dimethyl ether), (Fischer-Tropsch) fuels, and ammonia are $0.29/kg, $0.47/kg, $0.97/kg, and $2.09/kg, respectively, for a SilvaGas-based gasification plant with a capacity of 2000 dry tonnes/day. The cost of producing methanol, DME, F-T fuels, and ammonia in a RENUGAS-based plant are $0.45/kg, $0.69/kg, $1.53/kg, and $2.72/kg, respectively, for a plant capacity of 2000 dry tonnes/day. The minimum cost of producing methanol, DME, F-T fuels, and ammonia are $0.28/kg, $0.44/kg, $0.94/kg, and $2.06/kg at plant capacities of 3000, 3500, 4000, and 3000 dry tonnes/day, respectively, using the SilvaGas-based gasification process. Biomass-based fuels and chemicals are expensive compared to fuels and chemicals derived from fossil fuels, and carbon credits can help them become competitive.     

Comparison of the performance of several hybrid poplar clones and their potential suitability for use in northern China

The performance of 14 North American hybrid poplar clones was evaluated near Beijing in short-rotation plantations grown at a 1 × 1 m spacing. Significant clonal differences were found in eco-physiological and morphological characteristics. Clones DN-17, DN-2, DN-182, DN-14274, 328-162, and NM6 exhibited high emergence and survival rates, and DN-17, DN-14274, DN-182 and NE-222 had a short growing period. Other clones (306-45, 195-522, 184-411 and 328-162) had a long growing period and may be more suitable in southern China. Clones DN-2, DN-182, and 195-522, had the highest productivity and the best potential as biomass producers. Clones DN-14274, DN-17, DN-182, NE-222, and DTAC-7 allocated more belowground biomass than the other clones during the first growing season, indicating that they might be better adapted to arid regions such as those in northern China. Clones 195-522, 184-411, DTAC-7, NE-222, R-270 and 306-45 had a higher capacity for CO₂ assimilation. Clones NE-222, 306-45, DTAC-7, 195-522, R-270, 15-29, and DN-17 had a higher photosynthetic potential and could potentially adapt to a wide range of environmental conditions. Clones 195-522, 184-411, 328-162, DN-182, and NM6 had higher water-use efficiency than the others, suggesting that they would utilize soil water more effectively, especially in the dry season and in arid regions. Clones R-270, DN-14274, 15-29, DN-2, and DTAC-7 had higher transpiration rates, indicating that they would require frequent irrigation in the dry season and in arid regions to ensure normal survival and growth.     

A review on prognostics and health monitoring of Li-ion battery

The functionality and reliability of Li-ion batteries as major energy storage devices have received more and more attention from a wide spectrum of stakeholders, including federal/state policymakers, business leaders, technical researchers, environmental groups and the general public. Failures of Li-ion battery not only result in serious inconvenience and enormous replacement/repair costs, but also risk catastrophic consequences such as explosion due to overheating and short circuiting. In order to prevent severe failures from occurring, and to optimize Li-ion battery maintenance schedules, breakthroughs in prognostics and health monitoring of Li-ion batteries, with an emphasis on fault detection, correction and remaining-useful-life prediction, must be achieved. This paper reviews various aspects of recent research and developments in Li-ion battery prognostics and health monitoring, and summarizes the techniques, algorithms and models used for state-of-charge (SOC) estimation, current/voltage estimation, capacity estimation and remaining-useful-life (RUL) prediction.     

Organic richness,hydrocarbon potentiality,maturity, and timing of petroleum generation of the Cretaceous and Miocene source rocks in the central Gulf of Suez,Egypt

Total organic carbon (TOC) and pyrolysis analysis of the Cretaceous and Miocene source rocks in the central Gulf of Suez were evaluated throughout the 25 rock samples collected from 6 formations, namely Wata, Raha, Nubia “A” (Cretaceous source rocks); and Nukhul, Zeit, and Belayim (Miocene source rocks) from Gharib-252, Gharib-153, Gharib-163, Gharib-164, Gharib-167, and Gharib-165 wells. These data are used to study the probabilities of the source rock in the Cretaceous and Miocene source rocks in the central Gulf of Suez for the hydrocarbon generation through identifying the organic richness, type of organic matters, and thermal maturation of these organic materials. The results revealed that the Cretaceous formations are immature source rocks, ranging from fair to good source rocks and have kerogen of type III and type III/II. Meanwhile, Miocene source rocks, ranging from immature to marginally mature source rocks, are considered to range from good to very good source rocks for potential generation of both oil and gas and are characterized by kerogen of type III/II and type II.     

K2CO3浓度和保温时间对秸秆水热产物特性的影响

以水稻秆和玉米秆为原料,开展不同K2CO3浓度和保温时间下的水热炭化试验,研究秸秆水热炭和液体产物的理化特性.结果表明,随着K2CO3浓度的增大和保温时间的增加,水热炭产率从35.65％降至22.86％,气体产率从4.68％增至13.03％;液体产物的产率、pH值、电导率、NH4+-N浓度增大,PO43--P浓度减小;...     

广州市生活垃圾典型重金属污染及生态风险评价

以广州市的生活垃圾为研究对象,分析了22个生活垃圾样品的干基组分及典型重金属Hg、Cd、Pb、Cr的含量,采用污染指数法和潜在生态风险指数法进行了污染状况与潜在生态风险评价,并用皮尔森相关分析探讨了生活垃圾中Hg、Cd、Pb、Cr的可能来源。结果表明：（1）广州市生活垃圾中Hg、Cd、Pb和Cr浓度的平均值分别为0.435 mg/kg、1.487 mg/kg、71.865 mg/kg和136.088 mg/kg;Cd的污染最严重,Hg次之,Pb和Cr的污染程度较低,点位超标率分别为40.9%、22.7%、4.5%和18.1%;大部分生活垃圾样品出现了多金属复合污染,点位超标率为63.6%。（2）Cd的潜在生态风险最高,Hg次之,Pb和Cr无潜在生态风险;重金属污染物综合潜在生态风险指数的点位超标率为45.5%,部分样品出现高的潜在生态风险;（3）Cd和Pb可能主要来源于生活垃圾中的金属成份;Hg和Cr可能分别主要来源于生活垃圾中的白塑料成分和纸类成分。     

静电纺丝法制备硅碳纳米纤维及其在锂钠离子电池中的应用

静电纺丝法由于具有工艺简单、功能多样等优点,是一种重要的制备一维锂钠离子电池纳米结构电极材料的方法。目前,已有大量利用静电纺丝技术制备高性能电极材料的研究报道,但具有系统性和针对性的综述论文尚十分有限。碳材料是最早被研究且已实现商业化的锂离子电池负极材料,硅材料则是理论容量最高的负极材料,因此,两者一直是学术界和工业界关注的重点;但碳材料理论容量低和硅材料体积变化大的问题严重阻碍了各自更广泛的实际应用。静电纺丝技术被证明是一种可以解决上述问题的十分有效的方法。因此,本文系统地综述了静电纺丝法制备的硅基和碳基纳米纤维在锂钠离子电池负极材料上的应用和发展,重点从静电纺丝原理、硅碳材料的设计及合成、结构的调控与优化、复合材料的制备到电化学性能的提高等方面作了详细介绍和讨论,同时也指出静电纺丝法在大规模生产中的不足及未来可能的发展方向。希望此综述可以为先进储能材料（尤其是硅基和碳基纳米电极材料）的设计和制备提供一些有益的指导和帮助。     

Energetic and exergetic assessments of a novel solar power tower based multigeneration system with hydrogen production and liquefaction

In this article, a thermodynamic investigation of solar power tower assisted multigeneration system with hydrogen production and liquefaction is presented for more environmentally-benign multigenerational outputs. The proposed multigeneration system is consisted of mainly eight sub-systems, such as a solar power tower, a high temperature solid oxide steam electrolyzer, a steam Rankine cycle with two turbines, a hydrogen generation and liquefaction cycle, a quadruple effect absorption cooling process, a drying process, a membrane distillation unit and a domestic hot water tank to supply hydrogen, electrical power, heating, cooling, dry products, fresh and hot water generation for a community. The energetic and exergetic efficiencies for the performance of the present multigeneration system are found as 65.17% and 62.35%, respectively. Also, numerous operating conditions and parameters of the systems and their effects on the respective energy and exergy efficiencies are investigated, evaluated and discussed in this study. A parametric study is carried out to analyze the impact of various system design indicators on the sub-systems, exergy destruction rates and exergetic efficiencies and COPs. In addition, the impacts of varying the ambient temperature and solar radiation intensity on the irreversibility and exergetic performance for the present multigeneration system and its components are investigated and evaluated comparatively. According to the modeling results, the solar irradiation intensity is found to be the most influential parameter among other conditions and factors on system performance.     

全球加氢站产业、技术及标准进展综述

以美国、欧洲、日本、中国的加氢站作为考察对象,就产业投资运营、主要设备商、相关标准进行梳理,结果表明：在加氢站投资及运营管理方面,美国、欧洲、日本具有较为成熟的经验;在氢增压、储存、加注等技术方面,德国、日本保持领先地位。在诸多氢气和液氢的技术领域,美国保持领先地位;在一些细分技术领域,英国、法国、挪威、俄罗斯具有优势;在加氢站标准方面,美国、日本具有较为完善的标准体系。中国已解决70 MPa氢气增压、加注、储存等领域的部分技术难题,但与其他国家相比,离子液式氢压缩机、液氢泵、液氢储罐、液氢加氢枪等产品的研发仍需持续推进。     

A critical review of ash slagging mechanisms and viscosity measurement for low-rank coal and bio-slags

Gasification or combustion of coal and biomass is the most important form of power generation today. However, the use of coal/biomass at high temperatures has an inherent problem related to the ash generated. The formation of ash leads to a problematic phenomenon called slagging. Slagging is the accumulation of molten ash on the walls of the furnace, gasifier, or boiler and is detrimental as it reduces the heat transfer rate, and the combustion/gasification rate of unburnt carbon, causes mechanical failure, high-temperature corrosion and on occasions, superheater explosions. To improve the gasifier/combustor facility, it is very important to understand the key ash properties, slag characteristics, viscosity and critical viscosity temperature. This paper reviews the content, compositions, and melting characteristics of ashes in differently ranked coal and biomass, and discusses the formation mechanism, characteristics, and structure of slag. In particular, this paper focuses on low-rank coal and biomass that have been receiving increased attention recently. Besides, it reviews the available methodologies and formulae for slag viscosity measurement/prediction and summarizes the current limitations and potential applications. Moreover, it discusses the slagging behavior of different ranks of coal and biomass by examining the applicability of the current viscosity measurement methods to these fuels, and the viscosity prediction models and factors that affect the slag viscosity. This review shows that the existing viscosity models and slagging indices can only satisfactorily predict the viscosity and slagging propensity of high-rank coals but cannot predict the slagging propensity and slag viscosity of low-rank coal, and especially biomass ashes, even if they are limited to a particular composition only. Thus, there is a critical need for the development of an index, or a model or even a measurement method, which can predict/measure the slagging propensity and slag viscosity correctly for all low-rank coal and biomass ashes.     

Bioreactors and biophoton-driven biohydrogen production strategies

Given the current issues with global warming and rising greenhouse gas emissions, biohydrogen is a viable alternative fuel option. Technologies to produce biohydrogen include photo fermentation, dark fermentation, direct and indirect bio-photolysis, and two-stage fermentation. Biological hydrogen generation is a green and promising technique with mild reaction conditions and low energy consumption compared to thermochemical and electrochemical hydrogen generation. To optimize hydrogen gas output using this method, the activity of hydrogen-consuming bacteria should be restricted during the production stages of hydrogen and acetate to prevent or limit hydrogen consumption. Raw material costs, poor hydrogen evolution rates, and large-scale output are the main limitations in biological hydrogen generation systems. Organic wastes would be the most preferred target feedstock for hydrogen fermentation, aside from biodegradable wastes, due to their high amount and simultaneous waste treatment advantage. This study examined the three primary methods for converting waste into bio-hydrogen: microbial electrolysis cell, thermochemical gasification, and biological fermentation, from both a technological and environmental standpoint. The effectiveness and applicability of these bioprocesses in terms of aspects influencing processes and their constraints are discussed. Alternative options for improving process efficiency, like microbial electrolysis, bio-augmentation, and multiple process integration, are also considered for industrial-level applications. Biohydrogen generation might be further enhanced by optimization of operating conditions and adding vital nutrients and nanoparticles. Cost reduction and durability enhancement are the most significant hindrances to fuel-cell commercialization. This review summarizes the biohydrogen production pathways, the impact of used organic waste sources, and bacteria. The work also addresses the essential factors, benefits, and challenges.     

生物质燃烧过程中结焦、积灰及腐蚀形成机理及其制剂开发研究进展

大力发展生活垃圾及农林废弃物等生物质直接燃烧发电和煤炭掺烧生物质燃烧发电对缓解我国能源安全问题和实现“双碳”战略目标具有重要意义。然而生活垃圾和农林废弃物中较高含量的碱/碱土金属、硫、氯和硅等元素在高温燃烧过程中会发生复杂交互反应,导致锅炉结焦、积灰和腐蚀等一系列问题,严重影响锅炉的安全稳定运行。通过系统分析生活垃圾和农林废弃物等固体燃料燃烧过程中可能的结焦、积灰和腐蚀形成机理,探讨了原料灰分组成和结焦、积灰、腐蚀形成的关联关系和预测方法,在此基础上比较了不同类型结焦、积灰和腐蚀抑制剂的作用机制及其施加效果,并对未来高效抑制剂的开发进行了展望。     

The energy ecology derived from thermodynamic mass equivalence reveals critical energy reliability faults

The recent articulation of the thermodynamic mass-enthalpy equation on the basis of natural law was generalized and found to be compatible with observed wave-particle duality. Original causal derivations of premiere energy equations were obtained in a compact, interlocked manner, an energy ecology, which unifies historically disjointed physical concepts. The popular perception of the vacuo velocity of light was demoted to subconsequence status as a manifestation of the universal constant velocity found by extracting the square root of the universal proportionality constant between enthalpy and mass, the natural registry of which is given by the thermodynamic equivalence statement. All relationships with explicit vacuo light velocity connotations are affected. In particular, the classic formulae of Einstein, Planck, De Broglie and Compton are too. For the first time, an unambiguous natural law based method for performing absolute and coordinated mass and enthalpy balances is described. The methodology reveals the general presence of unexpected mass and enthalpy shortfalls in well studied systems wholly consistent with the existence of a novel fundamental particle. Dubbed the Avogadron, it has properties beyond and can function as both a companion to and a constituent of the entire inventory of known particles. As such, it represents a supraparticle, the first discovered, which appears to be the ultimate parcel of energy and matter with a universal presence in all processes and conversions. A sampling of the Avogadron's importance and applications is presented. The overall study revealed an enormous run of energy reliability conundrums which affect current science, technology and general practice. Popular expositions of thermodynamic law are shown to be misleading and prone to error. The fields of nuclear energy, medicine, genetics and weights and measures seem to be critically impacted. An international program for establishing definitive hierarchical energy codes, re-educating and re-qualifying personnel, conducting in-depth reliability assessments and implementing indicted correctives constitutes an immediate and dire imperative.     

煤层气储层类型及配套钻井方案概述

根据渗透率、压力、含气量等参数,可将煤层气储层分为Ⅰ类储层(好储层)、Ⅱ类储层(中等储层)、Ⅲ类储层(差储层)3大类。其中,Ⅰ类储层又分为高压高渗厚层状储层、高压高渗多层储层、高压高渗富气储层、高压高渗低含水储层;Ⅱ类储层又分为高压中渗薄层状储层、低压高渗中等含气储层、低压高渗贫气储层;Ⅲ类储层又分为低压低渗薄层储层、低压低渗厚层储层、低压低渗多层储层、低压低渗高起伏储层、低压低渗高含水储层。对于不同类型的储层,若要保证较好的产能,需要采取配套的钻井方案:Ⅰ类储层物性较好,可采用直井压裂或低分支水平井;Ⅱ类储层物性中等,可以采用三分支水平井、四分支水平井或U型井;Ⅲ类储层物性差、非均质性强,可采用羽状多分支水平井或丛式井,储层非均质性越强,羽状井主分支数应该越多。     

Innovative methodologies in renewable energy: A review

This paper is concerned with innovative approaches to renewable energy sources computation methodologies, which provide more refined results than the classical alternatives. Such refinements provide additional improvements especially for replacement of fossil energy usages that emit greenhouse gas (GHG) into the atmosphere leading to climate change impact. Current knowledge gap among each renewable energy source calculation is rather missing fundamentals of plausible, rational, and logical explanations for the interpretation of results. In the literature, there are rather complicated and mechanically applicable methodologies, which require input and output measurement data match with missing physical explanations. The view taken in this review paper is to concentrate on quite plausible, logical, rational, and effectively applicable innovative energy calculation methodologies with simplistic fundamentals. For this purpose, a set of renewable energy methodological approaches is revisited with their innovative structures concerning solar, wind, hydro, current, and geothermal energy resources. With the increase in the renewable energy utilizations to combat the undesirable impacts of global warming and climate change, there is a need for better models that will include physical environmental conditions and data properties in the probabilistic, statistical, stochastic, logical, and rational senses leading to refined and more reliable estimations with application examples in the text. Finally, new research directions are also recommended for more refined innovative energy system calculations.     

Exergy of Oat Straw

The exergy values of three oat straws were investigated. The effects of moisture content, ash content, S content, correlation factor (C, O, H, and N), and lower heating value (LHV) were also studied. The results showed that the moisture-related exergy, ash-related exergy, and S-related exergy varied in the ranges of 283.630–337.502, 28.474–111.054, and 4.357–13.944 kJ/kg, respectively. They accounted for 1.346–1.661%, 0.164–0.538%, and 0.021–0.068% of the exergy of oat straw, respectively. The O/C, H/C, and N/C atomic ratios varied in the ranges of 0.7042–0.7780 (10.480%), 1.4713–1.6000 (8.747%), and 0.0024–0.0254 (958.333%), respectively, whereas the correlation factors varied between 1.131 and 1.142 (0.973%). The exergy values of the three oat straws were between 20.325 and 21.065 MJ/kg. They were mainly determined by the correlation factors and the LHVs. A positive linear relationship between the exergy and LHV was observed.     

Agricultural waste resources and biogas energy potential in rural areas of Lao PDR

Lao PDR lacks of conventional energy resources, such as oil and natural gas, and 100% of fossil fuels are imported from abroad. Fossil fuel consumption in Lao PDR in 2010 was about 561 million liters and rapidly increased to 716 million liters by 2015. However, Lao PDR has a high potential for renewable energy, especially from hydropower, agricultural wastes, and livestock wastes, in which agricultural and livestock annually produced a large amount of agricultural residues as a favorable renewable energy sources. In 2016, productivity crops were estimated for 24,608,840 ton and these products amount can be generated annual agricultural residues for 12,525,000 ton, which can be estimated to total of energy potential was 197,840 GJ or 55,001 GWh. The majority of livestock in country are buffaloes, cattle, swine, and poultry; large amount of livestock manure produced from each region and can be feedstock as substrate for biogas digester, which these amounts were estimated about 1,583,740 kg TS/day, and equivalent to 439,917 m3/day of biogas production or 658,376 kWh/day of energy generation. Therefore, objective of this paper is unique to promote and research development the agroforestry residues and livestock wastes as renewable energy resources, and its energy potential for biofuel production, including, biodiesel, bioethanol and biogas in each region of Laos.