RH真空精炼技术的发展、现状及其设备组成

介绍了RH真空精炼技术的发展、现状,阐述了目前RH主要设备组成.     

WZ003441马钢订购真空脱气设备（RH）

德国SMSMevac真空公司最近接到了中国马鞍山钢铁公司的订单,要求提供1套新型复式真空脱气设备（RH）。该新型RH设备的特点是双位热处理系统,每个系统包括：     

WZ003466中钢公司订购真空循环脱气设备

德国SMSMevac真空公司最近收到了中国台湾钢铁公司的订货合同，要求提供1台250t真空循环脱气设备（RH设备），这是该公司订购的第6台RH设备。该合同内容包括：全套设备的设计、制造、交货；现场安装、调试、投产的监理以及培训用户人员。该RH设备主要生产汽车工业用的超低碳钢和制造变压器用的硅钢。     

基于生产运行数据的RH真空精炼装置可靠性分析

流程工业的生产运行数据虽然海量,但一般不直接反映设备的运行状况,需要设计针对性的方法获取可靠性数据。由炼钢车间的RH真空精炼炉连续生产记录数据和实际工艺流程,分离出故障数据,拟合出故障间隔时间分布模型,并进行参数估计和假设检验,确定现有RH运行的可靠性评价指标,并从可靠性角度分析RH顶枪对真空精炼装置的核心功能部件真空槽的影响。研究结果表明:在相同的生产环境下,SCAP顶枪和KTB顶枪对RH真空槽设备的运行可靠性影响相当,SCAP顶枪好于KTB顶枪。     

170t RH炉真空系统泄漏量的测试

介绍了安钢新建170t RH炉真空系统安装采取的措施,探讨了泄漏量的测试和计算方法。生产实践证明,采取的安装措施得当,泄漏量的测试和计算方法正确,新建的RH炉真空系统泄漏量达到了设计标准,满足了生产工艺的要求。     

炼钢工艺中RH脱气装置的节能措施

一、绪言 RH脱气处理是改善钢水质量的有效措施,但电和氩气的消耗量较大,为了节约用电和Ar消耗、降低生产成本,住友金属鹿岛制铁所对真空脱气装置存在的几个问题—真空漏气、蒸汽压力波动和结瘤等进行了研究,并取得了良好效果。RH处理时间平均缩短2分钟,综合能耗降低20.6％,耐火材料成本降低27.8％。     

RH一体式浸渍管真空槽结构与优化

开发了一种一体式浸渍管真空槽,并对其进行了流体仿真和热力仿真。一体式浸渍管真空槽扩大了浸渍管内径,可明显提高RH钢液循环流量。流体仿真发现减小浸渍管的中心距并不影响钢液循环的流态,而且可以找到提升气最大有效流量。热力仿真可以提前发现结构的热变形,有利于结构优化。工程应用证明,一体式浸渍管真空槽能够满足真空精炼处理的要求,是实现小口缘钢包RH高效生产的有效技术。     

单管RH真空脱碳过程的水模型研究

利用RH的水力学模型,分析了冶金操作参数和喷吹方式对单管RH和双管RH的RH真空溶氧和脱碳行为的影响。水模型结果表明:随着单管RH底吹气体流量的增大,二氧化碳的吸收速率和容积传质系数呈现先增大后保持不变的规律;提高单管RH顶吹气量能提高容积传质系数;增大单管RH真空度能提高二氧化碳的吸收和释放速率;单管双喷嘴RH的溶氧和脱碳效率要比传统双管侧吹RH提高26%和32%;对于单管RH,双喷嘴RH的脱碳效率要高于单喷嘴RH;对于双管RH,采用侧底复吹方式能够促进传质,提高脱碳效率。     

RH温度预报模型建模方法研究

RH温度主要受钢包、真空槽状态、铝氧反应、脱氧脱碳反应、合金化等因素影响。可以应用分段函数法、人工智能法、多元回归法、热传输机理、神经网络等方法进行温度预报模型建模,提高温度命中率指标,改善RH生产操作水平,提高温度控制稳定性,降低生产成本,指导RH工序生产。     

印度国家钢厂(SAIL)进口RH真空脱气设备

1998年7月,印度国家钢厂向奥地利奥钢联公司订购一台130tRH真空脱气设备。订货成套范围包括:带有加热喷嘴的RH脱气装置、升降机、合金设备、蒸汽喷射式真空泵、水清洁处理设备、除尘设备、钢包车、钢构架、电气装置、测量控制和调节器等设备。该厂利用该设备来生产高级合金钢和重轨钢坯。印度国家钢厂(SAIL)进口RH真空脱气设备     

A new thermoeconomic methodology for energy systems

Thermoeconomics, or exergoeconomics, can be classified into the three fields: cost allocation, cost optimization, and cost analysis. In this study, a new thermoeconomic methodology for energy systems is proposed in the three fields. The proposed methodology is very simple and clear. That is, the number of the proposed equation is only one in each field, and it is developed with a wonergy newly introduced in this paper. The wonergy is defined as an energy that can equally evaluate the worth of each product. Any energy, including enthalpy or exergy, can be applied to the wonergy and be evaluated by this equation. In order to confirm its validity, the CGAM problem and various cogenerations were analyzed. Seven sorts of energy, including enthalpy and exergy, were applied for cost allocation. Enthalpy, exergy, and profit were applied for cost optimization. Enthalpy and exergy were applied for cost analysis. Exergy is generally recognized as the most reasonable criterion in exergoeconomics. By the proposed methodology, however, exergy is the most reasonable in cost allocation and cost analysis, and all of exergy, enthalpy, and profit are reasonable in cost optimization. Therefore, we conclude that various forms of wonergy should be applied to the analysis of thermoeconomics.     

A review on alloyed quantum dots and their applications as photocatalysts

Semiconductor driven artificial photocatalysis is the most sustainable technology towards addressing the growing energy and environmental pollution issues. In this context, alloyed quantum dots (QDs) are an emerging class of promising nanomaterials gathering tremendous attention in this area due to several beneficial features. Compared to other bulk semiconductors, alloyed QDs are cost-effective, stable, less-toxic with superior optoelectronic features, which significantly enhances their solar energy conversion efficiency. Herein, the present review summarizes the fundamentals of alloyed QDs, various synthesis techniques, and discusses optical as well as structural properties from data interpretation point of view taking suitably reported literature. Moreover, we have provided a comprehensive summary of recent state of art metal chalcogenides based alloyed QD systems towards H₂ evolution, CO₂ reduction, and pollutant degradation. Finally, the review discusses the associated challenges and future prospects of alloyed QDs with a special focus on preparation, property engineering, theoretical aspect, stability and other field application. Additionally, the overarching aim is to provide researchers an in-depth understanding in the field of alloyed QDs relating to synthesis, characterisation, and promotes their photocatalytic applications, and can foster as a manual to future researchers.     

A comparison of conversion efficiencies of various sugars as reducing agents for the photosensitizer eosin in the photogalvanic cell

The efforts have been made to convert solar energy into electrical energy by eosin as photosensitizer with different sugars fructose, arabinose, D‐xylose, and mannose systems in photogalvanic cell along with providing them commercial viability using lower concentrations of the solutions. The generated photopotential and photocurrent are 848.0, 679.0, 825.0, and 758.0 mV and 240.0, 240.0, 250.0, and 170.0 μA, respectively. The maximum powers are 203.52, 162.96, 206.25, and 128.86 μW, respectively. The observed conversion efficiency is 0.8415, 0.6461 0.7026, and 0.6812% and the determined fill factors are 0.34, 0.37, 0.28, and 0.27 against the absolute value 1. The developed photogalvanic cell can work for 55.0, 75.0, 85.0, and 90.0 minutes in the dark. The photogeneration electricity is proved by a proposed mechanism. Conclusively, the photogalvanic cell so developed has shown appreciable conversion and storage of solar energy. Copyright © 2011 John Wiley & Sons, Ltd.     

Investigation of a new integrated system for multiple outputs with hydrogen and methanol

In this study, an integrated multigeneration system that can produce hydrogen, electricity, heat, and methanol simultaneously is thermodynamically investigated. This integrated multigeneration system consists of three subsystems, namely: (i) electrolyzer, (ii) thermal power plant; and (iii) methanol production reactor. Energy and exergy analyses of all system components, as well as the sustainability analysis of the whole system, is performed thoroughly. The integrated system's thermodynamic performance is thoroughly investigated by changing some critical operational and environmental parameters in parametric studies. Based on the results of this study, recommendations for better energetic, exergetic, and environmental performance are presented for better sustainability. The results of this study show that the integrated multigeneration system is capable of producing hydrogen, heat, electricity, and methanol with overall energetic and exergetic efficiencies about 68% and 47%, respectively.     

A chemical mechanism for low to high temperature oxidation of n-dodecane as a component of transportation fuel surrogates

Using surrogate fuels in lieu of real fuels is an appealing concept for combustion studies. A major limitation however, is the capability to design compact and reliable kinetic models that capture all the specificities of the simpler, but still multi-component surrogates. This task is further complicated by the fairly large nature of the hydrocarbons commonly considered as potential surrogate components, since they typically result in large detailed reaction schemes. Towards addressing this challenge, the present work proposes a single, compact, and reliable chemical mechanism, that can accurately describe the oxidation of a wide range of fuels, which are important components of surrogate fuels. A well-characterized mechanism appropriate for the oxidation of smaller hydrocarbon species [G. Blanquart, P. Pepiot-Desjardins, H. Pitsch, Chemical mechanism for high temperature combustion of engine relevant fuels with emphasis on soot precursors, Combust. Flame 156 (2009) 588–607], and several substituted aromatic species [K. Narayanaswamy, G. Blanquart, H. Pitsch, A consistent chemical mechanism for the oxidation of substituted aromatic species, Combust. Flame 157 (10) (2010) 1879–1898], ideally suited as a base to model surrogates, has now been extended to describe the oxidation of n-dodecane, a representative of the paraffin class, which is often used in diesel and jet fuel surrogates. To ensure compactness of the kinetic scheme, a short mechanism for the low to high temperature oxidation of n-dodecane is extracted from the detailed scheme of Sarathy et al. [S. M. Sarathy, C. K.Westbrook, M. Mehl, W. J. Pitz, C. Togbe, P. Dagaut, H. Wang, M. A. Oehlschlaeger, U. Niemann, K. Seshadri, Comprehensive chemical kinetic modeling of the oxidation of 2-methylalkanes from C₇ to C₂₀, Combust. Flame 158 (12) (2011) 2338–2357] and integrated in a systematic way into the base model. Rate changes based on recent rate recommendations from literature are introduced to the resulting chemical mechanism in a consistent manner, which improve the model predictions. Extensive validation of the revised kinetic model is performed using a wide range of experimental conditions and data sets.     

A comprehensive evaluation of energy storage options for better sustainability

Due to ever increasing global energy demand and the limited nature of fossil fuel reserves, there has been tremendous research and development studies in the literature, focusing on alternative and clean energy resources and systems. Renewables are the promising choice when it comes to addressing some critical energy issues such as climate change and energy security. However, renewables have intermittent and discontinuous supplies; hence, they need to be stored in ways that are affordable, reliable, flexible, clean, safe, and efficient. As a result, energy storage is becoming a crucial step to build innovative energy systems for a sustainable future. Energy can be stored in many forms, from electrical to chemical (eg, hydrogen), or electrochemical, thermal, electromagnetic, etc. Each form consists of different technologies, some of which are already commercially mature while others are at early research and development stages. Each of these options can be tailored to meet different end users' needs at different scales. Therefore, this study aims to conduct a comprehensive review on the most recent status of energy storage options, along with the requirements of various end users, and characteristics of smart energy storage systems. The main objective is to summarize the performance evaluation statuses of mechanical, electrochemical, chemical, thermal, and electromagnetic energy storage technologies. The selected performance measures are capacity flexibility, energy arbitrage, system balancing, congestion management, environmental impact, and power quality. In the end, some key recommendations and future directions for energy storage systems are provided.     

Combustion characteristics and flame stability of linear esters of palmitic acid based on OH-PLIF technology

Experimental study on combustion characteristics and method for evaluating flame stability was carried out. Methyl palmitate, ethyl palmitate, propyl palmitate, butyl palmitate, and amyl palmitate were prepared using pyridine n-butyl bisulfate ionic liquid as catalyst in a self-designed reactor to catalyze esterification reaction of palmitic acid with methanol, ethanol, propanol, butanol, and pentanol, respectively. Combustion characteristics including the flame height, flame front area, and flame speed were analyzed; and OH-PLIF time-average total signal strength by the OH-PLIF technique and cold flow properties of linear-chain alkyl esters of palmitic acid were also studied. Image diagnosis was applied to the study of flame stability, and an image segmentation method using three color feature matrices of flame corresponding to the red, green, and blue components was proposed. A color was selected as the evaluation color and the iterative method was used to obtain the optimal threshold for the area where the flame was located. Each pixel in the matrix was compared with an optimal threshold, and the flame stability was evaluated by calculating the ratio variance under continuous conditions. The method is simple in operation, accurate in repeatability, less interfered, and provides some guidance for analysis and optimization of biodiesel combustion process.     

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.     

Analysis of air conditioning system impact on a fuel cell vehicle performance based on a realistic model under actual urban conditions

In this study, a practical fuel cell vehicle considering the Heating, Ventilation, and Air conditioning system is considered to analyze hydrogen consumption under different working conditions. As a prevalent hydrogen-fueled vehicle, Toyota Mirai has been meticulously modeled in Simecenter Amesim software. The simulated model covers all of the vehicle's components with a concentration on Heating, Ventilation, and Air conditioning system. Since the air temperature and ‘weather conditions can significantly impact the vehicle's overall performance, various environmental conditions, including temperature variations, humidity, and varied solar fluxes, are taken into account. Furthermore, New York City is chosen as a densely populated megacity to simulate the dynamic behavior of the fuel cell vehicle under actual driving circumstances. The results illustrate that the Heating, Ventilation, and Air conditioning system can notably alter hydrogen consumption under real driving conditions. In this regard, turning on the Heating, Ventilation, and Air Conditioning system results in a 19% increase in fuel consumption. Moreover, the degradation phenomenon, which is a typical result of using fuel cell vehicles under urban driving conditions, impacts the vehicle's mileage and hydrogen consumption. The simulation results indicate that a fresh fuel cell stack consumes 80 g of hydrogen, while for 2500 and 5500 working hours fuel cells, the stack consumes 89.6 and 107 g of hydrogen, respectively. Based on the obtained results, a 33.75% increase in fuel consumption occurs by implementing a degraded fuel cell stack under real driving conditions.     

生物质高压液化制生物油研究进展

以生物质为原料进行高压液化制备生物油是目前生物质能领域研究的一个热点。纤维素在水中的降解是复杂的竞争和连串反应机理;在180℃以上,半纤维素就很容易水解,而且不管是酸还是碱都能催化半纤维素的水解反应;在水热条件下木质素会发生分解,生成多种苯酚、甲氧基苯酚等,这些产物可进一步被水解成甲氧基化合物。影响生物质液化产率及生物油组成的主要因素是温度、生物质类型和溶剂种类;次要因素包括停留时间、催化剂、还原性气体和供氢溶剂、加热速率、生物质颗粒大小、反应压力等。纤维素类生物质通过高压液化可以生产生物油,生物油经物理精制及化学加工可以制取车用燃料、生物气及化工产品等。生物油有轻油和重油之分,都是通过对生物质液化产物的分离精制而得到的。目前用来分析生物油的主要方法包括GC-MS(色-质联用)、EA(元素分析)、FTIR(傅里叶变换红外光谱)、HPLC(高效液相色谱)、NMR(核磁共振)、TOC(总有机碳测定)等。人们对生物质高压液化研究已经进行多年,并建立了几套工业试验示范装置。不过因为操作条件太苛刻,到目前为止还没有建立商业化装置。