近年来，固体氧化物燃料电池（SOFC）的电极组件的开发和制造已变得尤为重要，特别是在电极支撑的SOFC出现之后。电极的功能包括促进燃料气体的扩散，燃料的氧化，电子的传输以及电化学反应副产物的传输。在开发具有混合导电性能的替代电极材料和一些其他复合金属陶瓷方面，取得了令人瞩目的进展。在SOFC操作过程中，有必要避免渗碳和硫化问题。本论文论述了一种潜在电极材料，双钙钛矿作为SOFC中的阳极和阴极的各个方面，分析了文献中已研究的150多种SOFC电极组成。已经根据相，结构，衍射图，电导率和功率密度进行了评估，并详细提供了用于确定电极部件的质量的各种方法。这篇综述为未来的研究提出了可能的方向。

本文建立了基于热成像图像数据分析的定量的建筑物能量泄漏模型。 对于澳门大学横琴校区建筑物的门，窗和墙壁四个季节全天候的内部和外部表面两面的红外热像图均进行了测量。 基于就不同的局部瞬时内外表面温差和复合层多孔介质的传导模型获得基础单元的动态热流。基于建筑单元体的类型，朝向，和季节计算了对应的能量指数。 并根据不同季节空调系统的制冷和热泵循环的系统能源效率转换成对应的电能损失。 基于对应电表的电能消耗量，该模型得到了实际系统的验证。对应的春夏秋冬四季的热能计算误差别约为14.7％，12.8％，12.4％和15.8％。 夏季和冬季的电能计算误差分别为13.4％和5.4％。虽然冬季的热能泄漏量比夏天大，但是由于空调系统热泵循环的效率高过制冷循环，夏季的电量消耗远大于冬季。本单元体分解的热成像图像数据分析能量计算模型有望为实际的建筑能量泄漏提供一个实用可行的工具。

为应对全球变暖，控制和减少大气中的二氧化碳浓度至关重要。光催化还原二氧化碳制备燃料为解决该问题提供了方法，不仅能够对二氧化碳进行利用，而且同时生产了能源。目前为止，基于二氧化碳的半导体是在二氧化碳光催化还原中应用最为广泛的材料。因此，本篇小综述对近几年该领域的发展进行了总结。本文首先阐述了以结构工程的方法调控和提升二氧化碳催化剂性能的工作，之后描述了通过添加第二/第三种外源元素合成催化剂来改善二氧化碳催化剂的活性和选择性的工作。最后，本文介绍了基于二氧化碳的多元复合材料在二氧化碳催化还原中的应用。

This paper proposes a design of control and estimation strategy for induction motor based on the variable structure approach. It describes a coupling of sliding mode direct torque control (DTC) with sliding mode flux and speed observer. This algorithm uses direct torque control basics and the sliding mode approach. A robust electromagnetic torque and flux controllers are designed to overcome the conventional SVM-DTC drawbacks and to ensure fast response and full reference tracking with desired dynamic behavior and low ripple level. The sliding mode controller is used to generate reference voltages in stationary frame and give them to the controlled motor after modulation by a space vector modulation (SVM) inverter. The second aim of this paper is to design a sliding mode speed/flux observer which can improve the control performances by using a sensorless algorithm to get an accurate estimation, and consequently, increase the reliability of the system and decrease the cost of using sensors. The effectiveness of the whole composed control algorithm is investigated in different robustness tests with simulation using Matlab/Simulink and verified by real time experimental implementation based on dS pace 1104 board.

The key technologies of liquefied hydrogen have been developing rapidly due to its prospective energy exchange effectiveness, zero emissions, and long distance and economic transportation. However, hydrogen liquefaction is one of the most energy-intensive industrial processes. A small reduction in energy consumption and an improvement in efficiency may decrease the operating cost of the entire process. In this paper, the detailed progress of design and optimization for hydrogen liquefaction in recent years are summarized. Then, based on the refrigeration cycles, the hydrogen liquefaction processes are divided into two parts, namely precooled liquefaction process and cascade liquefaction process. Among the existing technologies, the SEC of most hydrogen liquefaction processes is limited in the range of 5–8 kWh/ {\mathrm{k}\mathrm{g}}_{{\mathrm{L}\mathrm{H}}_2} : liquid hydrogen). The exergy efficiencies of processes are around 40% to 60%. Finally, several future improvements for hydrogen liquefaction process design and optimization are proposed. The mixed refrigerants (MRs) as the working fluids of the process and the combination of the traditional hydrogen liquefaction process with the renewable energy technology will be the great prospects for development in near future.

在现在的应用场景中，电力系统企业主要关注智能电网技术，以实现可靠且利润丰厚的电网运行。而需求侧管理即是一种通过激励调动终端用户积极参与电力市场的智能电网技术。用户通过不同方式响应电网指令从而获得汇报。现今，居民用户热衷于采用电池等储能设备，以降低在高峰时段的用电量。本文通过优化居民用户的家用电器运行时间来降低整体电费，以此证明了智能建筑能量管理系统的有效性。进而，能量管理系统可以根据用户需求和电网参数（电价、消费限额等），通过调度电池的运行状态（充电/浮充/放电）和充放电量来有效利用电池。利用Matlab对能量管理系统进行了仿真研究，结果表明终端用户得到了显著的收益。

光伏发电作为一种可再生能源，其发展速度越来越快。然而，由于依赖于天气条件，光伏系统的缺点是其间歇性。因此，风力发电被认为有助于光伏发电系统稳定可靠的负荷输出，从而提高整个发电系统在并网模式下的动态性能。本文提出了一种基于光伏和风力发电机组的智能混合发电系统的拓扑结构。为了获取最大功率，在光伏系统中采用了混合模糊神经最大功率点跟踪（MPPT）方法。与传统方法相比，混合模糊神经方法的平均跟踪效率提高了约2个百分点。风力机的俯仰角由径向基函数网络滑模（RBFNSM）控制。仿真结果显示了不同的条件下实际功率值与所提出方法的比较。所得结果验证了本文提出方法的有效性和优越性，该方法具有鲁棒性、快速响应和良好的性能。利用Matlab/Simulink建立了三相并网智能混合系统的详细数学模型和控制方法。

Recently, renewable energy resources and their impacts have sparked a heated debate to resolve the Australian energy crisis. There are many projects launched throughout the country to improve network security and reliability. This paper aims to review the current status of different renewable energy resources along with their impacts on society and the environment. Besides, it provides for the first time the statistics of the documents published in the field of renewable energy in Australia. The statistics include information such as the rate of papers published, possible journals for finding relative paper, types of documents published, top authors, and the most prevalent keywords in the field of renewable energy in Australia. It will focus on solar, wind, biomass, geothermal and hydropower technologies and will investigate the social and environmental impacts of these technologies.

本文介绍了纳米网格系统的设计方法、项目实施和经济性。该系统的开发旨在通过实验室现场演示（FOLD）和“架通研究、开发和实施之间的鸿沟”，以使可再生技术适应印度社会。该系统由太阳能光伏（PV）（2.4 kWp）、风力发电机（3.2 kWp）和电池组（400 Ah）组成。首先，利用美国国家可再生能源实验室（NREL）开发的成熟的HOMER（电力可再生混合优化模型）软件进行了前期可行性研究。可行性研究表明，纳米电网系统的最佳容量由一台2.16 kWp太阳能光伏、一台3kWp风力发电机、一台1.44kw逆变器和一个24kWh电池组组成。系统的总净现值（TNPC）和能源成本（COE）分别为20789.85美元和0.673美元/kWh。然而，由于没有所需规格的系统组件，并且为了提高系统的可靠性，安装了由2.4 kWp太阳能光伏、3.2 kWp风力发电机、3 kVA逆变器和400 Ah电池组组成的混合系统。安装系统的TNPC和COE分别为20073.63美元和0.635美元/kWh，这两个成本在很大程度上受电池成本的影响。此外，本文还对各部件和系统的的安装细节进行了说明。另外，还讨论了系统的详细成本分解。进一步地，还对系统的性能进行了研究，并用仿真结果进行了验证。发现了在一年中来自光伏发电系统的发电量相当大，而且几乎是均匀的。与此相反，除4月、5月和6月外，一年中的风速很小，发电量也很小。本研究演示为在印度地区或类似地形地区，未来规划大规模混合能源系统或微电网提供了一条路径。

在当今世界尤其是能源领域，清洁、有效和持久的能源都备受关注。这三个方面也是科学家的主要关注目标。然而，化石能源和可持续能源等各类型能源在能源转换、储存和能效方面仍面临一些挑战。因此，眼下最可靠的能源应该是一种尽可能高效、清洁且能被永久利用的能源。本综述重点强调一种有前途的清洁高效能源类型，即固体氧化物燃料电池(SOFC)，这是以氢气和碳氢化合物为燃料的燃料电池中效率最高的一种，尤其是在热电联产（CHP）下工作时。这种燃料电池的重要性在于其通过化学反应发电时无噪音，无污染，并且安全。

金属有机框架 (metal-organic frameworks, MOFs) 材料因其具有高比表面积，可调结构，以及功能多样化等特点而备受关注。目前，MOFs在光催化还原二氧化碳领域已经崭露头角。本文综述了近年来MOFs在光催化还原二氧化碳领域的最新研究进展。此外, 本文讨论了基于MOF的光催化剂的合理设计策略 (功能化原始 MOF结构、MOF -光敏剂、MOF-半导体、MOF-金属和 MOF-碳材料复合材料) 以有效增强光催化二氧化碳还原反应，并对MOFs在光催化还原二氧化碳领域今后的发展进行了展望。

干热岩作为一种新型地热资源，在中国有着广阔的应用前景。通过假设共和盆地干热岩热电站应用场景，本文对两种适用的底部循环进行了对比。基于干热岩资源的产热特性，分别开展了一种Kalina循环与7个不同浓度氨水工质、三种ORC循环与9个环保型有机工质组合的仿真研究。结果显示，当氨水工质浓度为82%时，Kalina循环的净发电量可以达到最大；而对于ORC循环中的有机工质，超临界膨胀有利于湿工质提升净发电量，饱和膨胀则是干工质提升发电能力的最佳选择。进一步，采用干工质进行饱和膨胀的ORC循环净发电量整体优于其他工质和膨胀方式组合的净发电量，且显著高于测试的所有Kalina循环组合发电能力。因而，在共和盆地干热岩产热特性下，推荐采用干工质进行饱和膨胀的ORC循环，以实现最大的净发电量。

Solid-state electrolytes (SSEs) can address the safety issue of organic electrolyte in rechargeable lithium batteries. Unfortunately, neither polymer nor ceramic SSEs used alone can meet the demand although great progress has been made in the past few years. Composite solid electrolytes (CSEs) composed of flexible polymers and brittle but more conducting ceramics can take advantage of the individual system for solid-state lithium metal batteries (SSLMBs). CSEs can be largely divided into two categories by the mass fraction of the components: “polymer rich” (PR) and “ceramic rich” (CR) systems with different internal structures and electrochemical properties. This review provides a comprehensive and in-depth understanding of recent advances and limitations of both PR and CR electrolytes, with a special focus on the ion conduction path based on polymer-ceramic interaction mechanisms and structural designs of ceramic fillers/frameworks. In addition, it highlights the PR and CR which bring the leverage between the electrochemical property and the mechanical property. Moreover, it further prospects the possible route for future development of CSEs according to their rational design, which is expected to accelerate the practical application of SSLMBs.

Nuclear reactor safety (NRS) and the branch accident analysis (AA) constitute proven technologies: these are based on, among the other things, long lasting research and operational experience in the area of water cooled nuclear reactors (WCNR). Large break loss of coolant accident (LBLOCA) has been, so far, the orienting scenario within AA and a basis for the design of reactors. An incomplete vision for those technologies during the last few years is as follows: Progress in fundamentals was stagnant, namely in those countries where the WCNR were designed. Weaknesses became evident, noticeably in relation to nuclear fuel under high burn-up. Best estimate plus uncertainty (BEPU) techniques were perfected and available for application. Electronic and informatics systems were in extensive use and their impact in case of accident becomes more and more un-checked (however, quite irrelevant in case of LBLOCA). The time delay between technological discoveries and applications was becoming longer. The present paper deals with the LBLOCA that is inserted into the above context. Key conclusion is that regulations need suitable modification, rather than lowering the importance and the role of LBLOCA. Moreover, strengths of emergency core cooling system (ECCS) and containment need a tight link.

The Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) gGmbH as the main technical support organization for the German Federal Government in nuclear safety has been dealing with small modular reactors (SMRs) for about one decade since SMRs are one interesting option for new builds in most countries worldwide which continue to use nuclear energy for commercial electricity production. Currently four different SMR designs are in operation, four in construction, one is licensed, and further 12 are in a licensing process. In this paper, definitions, history, and current developments of SMRs are presented. Subsequently, selected trends of SMR development such as factory fabrication and transport, compactness and modularity, core design, improved core cooling, exclusion of accidents, features for preventing and limiting the impact of severe accidents, economic viability, competitiveness and licensing are discussed. Modeling gaps of the GRS simulation chain programs with a view to applications in nuclear licensing procedures are identified and a strategy for closing these gaps is presented. Finally, selected work on the extension and improvement of the simulation chain and first generic test analyses are presented.

The brazed plate heat exchanger (BPHE) has some advantages over the plate-fin heat exchanger (PFHE) when used in natural gas liquefaction processes, such as the convenient installation and transportation, as well as the high tolerance of carbon dioxide (CO₂) impurities. However, the BPHEs with only two channels cannot be applied directly in the conventional liquefaction processes which are designed for multi-stream heat exchangers. Therefore, the liquefaction processes using BPHEs are different from the conventional PFHE processes. In this paper, four different liquefaction processes using BPHEs are optimized and comprehensively compared under respective optimal conditions. The processes are compared with respect to energy consumption, economic performance, and robustness. The genetic algorithm (GA) is applied as the optimization method and the total revenue requirement (TRR) method is adopted in the economic analysis. The results show that the modified single mixed refrigerant (MSMR) process with part of the refrigerant flowing back to the compressor at low temperatures has the lowest specific energy consumption but the worst robustness of the four processes. The MSMR with fully utilization of cold capacity of the refrigerant shows a satisfying robustness and the best economic performance. The research in this paper is helpful for the application of BPHEs in natural gas liquefaction processes.

光催化剂由于其优异的性能和同时解决能源需求和环境污染方面的挑战的潜力而引起了广泛的研究兴趣。 实际应用中光催化颗粒需要与它们各自的介质接触才能表现出高效的光催化能。 然而，纳米级的光催化材料后期很难从反应介质中分离出来，不可避免的会导致二次污染和比较差得循环行能。 三维网络结构的水凝胶光催化材料具有高比表面积、高吸附能力和良好的环境相容性等特点，是一种很有前途的光催化剂载体材料。 本文根据水凝胶光催化材料的组成将其分为两类，并对近年来水凝胶光催化材料的制备方法进行了总结。 此外，综述了目前水凝胶光催化材料在能源转化和环境修复中的应用。 并对水凝胶光催化材料所遇到的挑战和发展前景进行了简要阐述。

室温液态金属（LM）是近年来兴起的一大类多功能材料，因其在先进热管理、增材制造、柔性电子、生物医学工程、柔性机器等方面的重大价值而日益受到广泛关注。此类材料异常丰富的功能用途主要源于其同时具有传统金属特性及流体流动的双重属性，熔点是其中最为典型的热物性参数之一，也是液态金属应用于热学领域如相变材料（PCM）、先进散热等的关键因素。目前，学术界已部分引入了一些可行的研究策略，如分子动力学模拟（MD）、经典热力学理论等，以尝试分析液态金属熔化过程的动态特征；而如何结合相图分析、第一性原理模拟计算等多尺度理论工具，对室温液态多元合金的熔点加以分析、预测乃至设计，更是一个至关重要的问题，这对于今后研制可在特定热学场合下发挥作用的新一代液态金属功能材料，具有十分迫切现实的重要价值。本文旨在围绕液态金属的热物理变化规律，探讨其熔化过程中的熔点参数。首先基于研究对象的物理尺度，对研究液态金属熔化相变的经典理论方法进行了梳理和深入解读；其次，总结并评估了可能对液态金属熔化过程产生关键影响的有关参数，如金属组分、环境压强、颗粒尺寸以及过冷度等，对这些参数的深入认识有助于高效筛选乃至尝试设计出具有特定熔点的合金。最后，文章介绍了基于液态金属低熔点特性所衍生出的部分典型应用设计，这些实践表明了前述理论探究的价值所在。最后需要指出的是，液态金属熔化物理学方面的基础探索还存在很大的拓展空间，仍需大量的理论与实验工作。

In this paper, a novel accelerated test method was proposed to analyze the durability of MEA, considering the actual operation of the fuel cell vehicle. The proposed method includes 7 working conditions: open circuit voltage (OCV), idling, rated output, overload, idling-rated cycle, idling-overload cycle, and OCV-idling cycle. The experimental results indicate that the proposed method can effectively destroy the MEA in a short time (165 h). Moreover, the degradation mechanism of MEA was analyzed by measuring the polarization curve, CV, SEM and TEM. This paper may provide a new research direction for improving the durability of fuel cell.

As a new clean energy resource in the 21st century, natural gas hydrate is considered as one of the most promising strategic resources in the future. This paper, based on the research progress in exploitation of natural gas hydrate (NGH) in China and the world, systematically reviewed and discussed the key issues in development of natural gas hydrate. From an exploitation point of view, it is recommended that the concepts of diagenetic hydrate and non-diagenetic hydrate be introduced. The main factors to be considered are whether diagenesis, stability of rock skeleton structure, particle size and cementation mode, thus NGHs are divided into 6 levels and used unused exploitation methods according to different types. The study of the description and quantitative characterization of abundance in hydrate enrichment zone, and looking for gas hydrate dessert areas with commercial exploitation value should be enhanced. The concept of dynamic permeability and characterization of the permeability of NGH by time-varying equations should be established. The ‘Three-gas co-production’ (natural gas hydrate, shallow gas, and conventional gas) may be an effective way to achieve early commercial exploitation. Although great progress has been made in the exploitation of natural gas hydrate, there still exist enormous challenges in basic theory research, production methods, and equipment and operation modes. Only through hard and persistent exploration and innovation can natural gas hydrate be truly commercially developed on a large scale and contribute to sustainable energy supply.

本文建立了一个热发电系统的热力学和经济性综合模型，预测和比较例如采用传统和新型集热管的槽式热发电系统的性能。仿真结果表明，与传统集热管相比，采用新型集热管的发电系统具有更优越的热力学和经济性能。当集热场出口温度为550℃，位于凤凰城、塞维利亚和托托河采用新型集热管的热发电站的年发电量分别提高了8.5%、10.5%和14.4%，单位电力成本分别降低了6.9%、8.5%和11.6%。在凤凰城，通过采用新型集热管，发电站的最佳运行温度从500℃提高到560℃。此外，还对集热管热损失、涂层的吸收率和熔盐防凝温度进行了敏感性研究，以分析集热管性能对电站性能影响的一般规律。结果表明，低热损集热管与低熔点熔盐配置是改善太阳能热发电站综合性能的有效措施。

以水热法合成的TiO₂和三聚氰胺（MA）为原料，采用原位氮化法制备了氮化钛（TiN）修饰的N-掺杂二氧化钛（N-TiO₂）复合材料（TiN/N-TiO₂）。通过优化反应条件，得到的TiN/N-TiO₂复合材料在氙灯全光谱照射下的析氢活性高达703μmol h^-1，分别是单纯的TiO₂和TiN的2.6倍和32.0倍。为了探索其光催化反应机理，对复合材料的晶相、形貌、光吸收性能、能带结构、元素组成和电化学行为进行了表征和分析。结果表明，TiN/N-TiO₂复合材料光催化活性的提高主要是由于在原位生产的TiN和N-TiO₂界面形成了紧密的接触，这不仅扩展了复合材料的光谱响应范围，而且可加速TiN光激发热载流子的转移和分离。本研究为原位制备具有高效分解水产氢活性的非金属等离子体材料/N-掺杂TiO₂复合光催化材料提供了一条新的途径。

在柴油乳化燃料中加入水可以减少柴油发动机的氮氧化物的排放，而无需对发动机进行任何改装。在本文中，首先利用超声波辐射法制作了含不同水配方的柴油乳化燃料。并通过实验测得了乳液中的水滴大小、多分散指数以及所制作燃料的稳定性。然后研究了单缸风冷柴油发动机在使用含不同水配方的柴油乳化燃料条件下的性能特征和废气排放情况。将响应曲面设计作为响应面法的子集，测得了含水量（按体积计，范围为5%–10%）、表面活性剂含量（按体积计，范围为0.5%–2%）以及亲水亲脂平衡值（范围为5–8）的影响。在考虑多目标优化的条件下，我们发现最佳的乳化燃料的配方为5%的水，2%的表面活性剂和6.8的亲水亲脂平衡值。最后将所得最佳乳化燃料和纯柴油在发动机性能和排放特性方面进行了对比。相比于纯柴油，所得最佳乳化燃料的氮氧化物的排放量明显减少（–18.24%）。

There is nothing illogical in the concept that hydrates are easily formed in oil and gas pipelines owing to the low-temperature and high-pressure environment, although requiring the cooperation of flow rate, water content, gas-liquid ratio, and other specific factors. Therefore, hydrate plugging is a major concern for the hydrate slurry pipeline transportation technology. In order to further examine potential mechanisms underlying these processes, the present paper listed and analyzed the significant research efforts specializing in the mechanisms of hydrate blockages in the liquid-rich system, including oil-based, water-based, and partially dispersed systems (PD systems), in gathering and transportation pipelines. In addition, it summarized the influences of fluid flow and water content on the risk of hydrate blockage and discussed. In general, flow rate was implicated in the regulation of blockage risk through its characteristic to affect sedimentation tendencies and flow patterns. Increasing water content can potentiate the growth of hydrates and change the oil-water dispersion degree, which causes a transition from completely dispersed systems to PD systems with a higher risk of clogging. Reasons of diversity of hydrate plugging mechanism in oil-based system ought to be studied in-depth by combining the discrepancy of water content and the microscopic characteristics of hydrate particles. At present, it is increasingly necessary to expand the application of the hydrate blockage formation prediction model in order to ensure that hydrate slurry mixed transportation technology can be more maturely applied to the natural gas industry transportation field.

Metals are unconventional hydrogen production materials which are of high energy densities. This paper comprehensively reviewed and digested the latest researches of the metal-based direct hydrogen generation and the unconventional energy utilization ways thus enabled. According to the metal activities, the reaction conditions of metals were generalized into three categories. The first ones refer to those which would violently react with water at ambient temperature. The second ones start to react with water after certain pretreatments. The third ones can only react with steam under somewhat harsh conditions. To interpret the metal-water reaction mechanisms at the molecular scale, the molecule dynamics simulation and computational quantum chemistry were introduced as representative theoretical analytical tools. Besides, the state-of-the-art of the metal-water reaction was presented with several ordinary metals as illustration examples, including the material treatment technologies and the evaluations of hydrogen evolution performances. Moreover, the energy capacities of various metals were summarized, and the application potentials of the metal-based direct hydrogen production approach were explored. Furthermore, the challenges lying behind this unconventional hydrogen generation method and energy strategy were raised, which outlined promising directions worth of further endeavors. Overall, active metals like Na and K are appropriate for rapid hydrogen production occasions. Of these metals discussed, Al, Mg and their alloys offer the most promising hydrogen generation route for clean and efficient propulsion and real-time power source. In the long run, there exists plenty of space for developing future energy technology along this direction.

China’s accelerator driven subcritical system (ADS) development has made significant progress during the past decade. With the successful construction and operation of the international prototype of ADS superconducting proton linac, the lead-based critical/subcritical zero-power facility VENUS-II and the comprehensive thermal-hydraulic and material test facilities for LBE (lead bismuth eutectic) coolant, China is playing a pivotal role in advanced steady-state operations toward the next step, the ADS project. The China initiative Accelerator Driven System (CiADS) is the next facility for China’s ADS program, aimed to bridge the gaps between the ADS experiment and the LBE cooled subcritical reactor. The total power of the CiADS will reach 10 MW. The CiADS engineering design was approved by Chinese government in 2018. Since then, the CiADS project has been fully transferred to the construction application stage. The subcritical reactor is an important part of the whole CiADS project. Currently, a pool-type LBE cooled fast reactor is chosen as the subcritical reactor of the CiADS. Physical and thermal experiments and software development for LBE coolant were conducted simultaneously to support the design and construction of the CiADS LBE-cooled subcritical reactor. Therefore, it is necessary to introduce the efforts made in China in the LBE-cooled fast reactor to provide certain supporting data and reference solutions for further design and development for ADS. Thus, the roadmap of China’s ADS, the development process of the CiADS, the important design of the current CiADS subcritical reactor, and the efforts to build the LBE-cooled fast reactor are presented.

Gasoline compression ignition (GCI) combustion faces problems such as high maximum pressure rise rate (MPRR) and combustion deterioration at high loads. This paper aims to improve the engine performance of the GCI mode by regulating concentration stratification and promoting fuel-gas mixing by utilizing the double main-injection (DMI) strategy. Two direct injectors simultaneously injected gasoline with an octane number of 82.7 to investigate the energy ratio between the two main-injection and exhaust gas recirculation (EGR) on combustion and emissions. High-load experiments were conducted using the DMI strategy and compared with the single main-injection (SMI) strategy and conventional diesel combustion. The results indicate that the DMI strategy have a great potential to reduce the MPRR and improve the fuel economy of the GCI mode. At a 10 bar indicated mean effective pressure, increasing the main-injection-2 ratio (R_m-2) shortens the injection duration and increases the mean mixing time. Optimized R_m-2 could moderate the trade-off between the MPRR and the indicated specific fuel consumption with both reductions. An appropriate EGR should be adopted considering combustion and emissions. The DMI strategy achieves a highly efficient and stable combustion at high loads, with an indicated thermal efficiency (ITE) greater than 48%, CO and THC emissions at low levels, and MPRR within a reasonable range. Compared with the SMI strategy, the maximum improvement of the ITE is 1.5%, and the maximum reduction of MPRR is 1.5 bar/°CA.

Presently, the global search for alternative renewable energy sources is rising due to the depletion of fossil fuel and rising greenhouse gas (GHG) emissions. Among alternatives, hydrogen (H₂) produced from biomass gasification is considered a green energy sector, due to its environmentally friendly, sustainable, and renewable characteristics. However, tar formation along with syngas is a severe impediment to biomass conversion efficiency, which results in process-related problems. Typically, tar consists of various hydrocarbons (HCs), which are also sources for syngas. Hence, catalytic steam reforming is an effective technique to address tar formation and improve H₂ production from biomass gasification. Of the various classes in existence, supported metal catalysts are considered the most promising. This paper focuses on the current researching status, prospects, and challenges of steam reforming of gasified biomass tar. Besides, it includes recent developments in tar compositional analysis, supported metal catalysts, along with the reactions and process conditions for catalytic steam reforming. Moreover, it discusses alternatives such as dry and autothermal reforming of tar.

Advances in natural gas-fired technologies have deepened the coupling between electricity and gas networks, promoting the development of the integrated electricity-gas network (IEGN) and strengthening the interaction between the active-reactive power flow in the power distribution network (PDN) and the natural gas flow in the gas distribution network (GDN). This paper proposes a day-ahead active-reactive power scheduling model for the IEGN with multi-microgrids (MMGs) to minimize the total operating cost. Through the tight coupling relationship between the subsystems of the IEGN, the potentialities of the IEGN with MMGs toward multi-energy cooperative interaction is optimized. Important component models are elaborated in the PDN, GDN, and coupled MMGs. Besides, motivated by the non-negligible impact of the reactive power, optimal inverter dispatch (OID) is considered to optimize the active and reactive power capabilities of the inverters of distributed generators. Further, a second-order cone (SOC) relaxation technology is utilized to transform the proposed active-reactive power scheduling model into a convex optimization problem that the commercial solver can directly solve. A test system consisting of an IEEE-33 test system and a 7-node natural gas network is adopted to verify the effectiveness of the proposed scheduling method. The results show that the proposed scheduling method can effectively reduce the power losses of the PDN in the IEGN by 9.86%, increase the flexibility of the joint operation of the subsystems of the IEGN, reduce the total operation costs by $32.20, and effectively enhance the operation economy of the IEGN.

Natural gas hydrate is an alternative energy source with a great potential for development. The addition of surfactants has been found to have practical implications on the acceleration of hydrate formation in the industrial sector. In this paper, the mechanisms of different surfactants that have been reported to promote hydrate formation are summarized. Besides, the factors influencing surfactant-promoted hydrate formation, including the type, concentration, and structure of the surfactant, are also described. Moreover, the effects of surfactants on the formation of hydrate in pure water, brine, porous media, and systems containing multiple surfactants are discussed. The synergistic or inhibitory effects of the combinations of these additives are also analyzed. Furthermore, the process of establishing kinetic and thermodynamic models to simulate the factors affecting the formation of hydrate in surfactant-containing solutions is illustrated and summarized.