Energy and environmental analysis of an entire coke production plant using ECLIPSE

In the present work the sequential code ECLIPSE is used to perform an energy analysis of an entire industrial process—a coke production plant—aiming its characterization and optimization in terms of energy requirements and environmental impact. The code is validated by comparing its results against existing experimental data acquired at the above‐referred plant, for the present operating conditions. Agreement is observed to be rather good, as the maximum relative errors between the ECLIPSE predictions and the actual values are 9.2, 9.7 and 8.7 per cent, respectively, for mass flows, temperatures and pressures. Moreover, those errors occur only once and at different streams, the vast majority of the relative errors for the remaining streams being below 1.0 per cent. In order to optimize the process both as far as energy and environmental aspects are concerned, alternative or new unit operations are suggested and are included in the production flow sheet or added to it and the entire new processes are simulated. More specifically, the better sealing of the coke ovens doors eliminating 80 per cent of the volatiles escape, the recovery of the lost sensible heat in the coke extinction operation and the restart of the 10 non‐productive coke ovens would yield remarkable energy savings—losses would reduce from 46 440 to 9260 kW, apart from the environmental benefits emerging from the elimination of the volatiles escape to the atmosphere. In addition, for the coke gas cleansing sub‐process, the substitution of the stripping process in the column distillation by a separation process, making recourse to a reverse osmosis installation, together with the operation setting of the ammonium destruction oven at a more convenient temperature, would allow both for energy savings of 66 per cent and a substantial reduction in both gaseous and liquid emissions, namely naphthalene, ammonia, nitric oxides and sulphur oxides. The improvements attained are noticeable and encouraging. Therefore, ECLIPSE proved to be an adequate tool for global industrial processes simulation, analysis and optimization, in spite of some limitations exhibited by the code in simulating detailed complex physical phenomena, such as combustion or coal distillation. Copyright © 2001 John Wiley & Sons, Ltd.     

Options for the Swedish steel industry - Energy efficiency measures and fuel conversion

The processes of iron and steel making are energy intensive and consume large quantities of electricity and fossil fuels. In order to meet future climate targets and energy prices, the iron and steel industry has to improve its energy and resource efficiency. For the iron and steel industry to utilize its energy resources more efficiently and at the same time reduce its CO₂ emissions a number of options are available. In this paper, opportunities for both integrated and scrap-based steel plants are presented and some of the options are electricity production, fuel conversion, methane reforming of coke oven gas and partnership in industrial symbiosis. The options are evaluated from a system perspective and more specific measures are reported for two Swedish case companies: SSAB Strip Products and Sandvik AB. The survey shows that both case companies have great potentials to reduce their CO₂ emissions.     

钢铁厂焦化及烧结工序热量利用效率及余热资源评价

针对钢铁生产流程中焦化及烧结工序的能量平衡、热效率及火用效率等展开研究,并对各种余热资源的能级等进行了计算和评价。在焦炉产生的余热资源中,红焦的焓值和火用值均高于其他两项,说明红焦余热量大,并且余热品质好。焦炉煤气的比焓值和比火用值均大于焦炉烟气,说明焦炉煤气的能量品质要好于焦炉烟气,而焦炉烟气的焓值大于焦炉煤气。烧结矿的比焓值和比火用值均比烧结烟气和环冷废气的比焓值和比火用值高,说明烧结矿的余热资源量和余热品质均高于烧结烟气和环冷废气。这项研究为焦化工序及烧结工序余热利用等奠定了基础。     

基于预测控制的焦炉加热控制系统的研究

针对焦炉燃烧过程的特点,提出了一种分别以预测控制和PI控制为主副回路的串级控制方法。预测控制算法通过模型预测,在线滚动优化和误差校正等环节,在没有精确模型的情况下也能实现良好的控制性能。研究结果表明,这一控制方法应用在焦炉加热系统中可以取得良好的效果。     

Exergoeconomic analysis of the power generation system using blast furnace and coke oven gas in a Brazilian steel mill

The rational use of energy has become a priority for all industries in Brazil, mainly after the energy rationing in 2001. Methodologies to quantify and improve the performance of plants that consume and generate electricity and thermal energy are being used to reach this goal. Exergoeconomic analysis provides a complete diagnosis of a plant, both in exergetic and in monetary values. This study shows the methodology used to assess the power generation system of the Companhia Siderúrgica Tubarão (CST). The current system is based on a regenerative Rankine cycle using two gases from steel production – blast furnace gas (BFG) and coke oven gas (COG) – to generate electric power and occasionally steam for the process. Use of the Theory of Exergetic Cost allowed determination of monetary and exergetic costs. Moreover, indicators such as cost variation, relative cost variation, and exergoeconomic factors were calculated to determine the influence of each component in the make-up of plant costs and to find the best way of decreasing generation costs of energy and process steam.     

BP人工神经网络在钢铁生产过程信息流分析中的应用

钢铁企业生产过程的信息流蕴藏着丰富的生产工艺规律。BP人工神经网络广泛用于信息流分析中,将其概括为四个方面:过程状态参数预测、产品性能参数预测、能耗信息预测和原材料参数优化。分别介绍相关研究和应用工作,指出应用流程中存在的不足,并给出规范流程。最后给出某大型钢铁企业新区焦炉单元的日能耗预测实例,验证了BP人工神经网络在钢铁生产过程信息流分析中的作用和应用流程的有效性。     

焦炉煤气竖炉法生产DRI的还原煤气用量

近年来,由于废钢短缺,DRI生产越来越受到重视。在直接还原生产工艺中,气基竖炉法占绝对优势,但此法只适合天然气资源充足地区。用焦炉煤气生产DRI既可解决气源问题,又可高效利用焦炉煤气,但目前该工艺尚未工业化,成为当前科研工作者们的研究焦点之一。基于理论计算,从还原剂的角度来探讨焦炉煤气竖炉法生产直接还原铁(DRI)的还原煤气用量,拟为该工艺的实施提供工艺参数。     

Analysis of a repowering proposal to the power generation system of a steel mill plant through the exergetic cost method

The rational use of energy became a priority for all industries in Brazil after the energetic rationing in 2001. The aim of this work is to assess a proposal of a power generation system for Companhia Siderúrgica Tubarão, a steel mill plant. The current system is based on a regenerative Rankine cycle using two gases from steel production—blast furnace gas (BFG) and coke oven gas (COG)—to generate electric power and occasionally steam for the process. The proposed system is a combined cycle comprising two gas turbines, two heat recovery steam generators (HRSGs), and a steam turbine. The fuel for the gas turbines is BFG, and the supplementary firing of HRSG uses COG. The proposed HRSGs work at three pressure levels. The system was assessed by means of two thermoeconomic methodologies, Theory of Exergetic Cost and Thermoeconomic Functional Analysis; exergetic and monetary costs of power production were calculated and compared to the respective values of the current system.     

On the use of ECLIPSE code for optimizing industrial processes

The sequential code ECLIPSE is used in the present work to perform a technical analysis of two industrial processes—a coke gas cleansing plant and a power plant—aiming their energetic and environmental optimization. The code is validated herein comparing its results against existing experimental data acquired at the above-referred plants, for the present operating conditions. Agreement is observed to be rather good. In order to optimize both processes as far as energy and environment aspects are concerned, alternative unit operations are suggested and are included in the production flow sheet and entirely new processes are simulated. The improvements attained in both processes are noticeable. Therefore, ECLIPSE proved to be an adequate tool for global industrial processes simulation, analysis and optimization. However, the code exhibits some limitations in simulating detailed complex physical phenomena, such as combustion. © 1998 John Wiley & Sons, Ltd.     

焦炉直行温度数学模型及其在宝钢三期焦炉中的应用实践

在详尽分析了宝钢三期焦炉热工工艺特点的基础上，建立了焦炉直行温度数学模型。采用现场实测的立火道温度对所建立的数学模型进行了验证，在此基础上仿真计算了不同工况对焦炉直行温度和加热煤气流量等主要热工参数的影响，所做工作为焦炉的计算机优化加热控制奠定了坚实的理论基础。     

焦炉煤气制氢与车载二甲醚重整制氢的能耗与CO_2排放对比

本文分别建立了焦炉煤气制氢与车载二甲醚重整制氢生产及运输过程的模型,分析了两个过程中的总能耗与CO2总排放情况。结果表明在中短途运输中,车载二甲醚重整制氢的总能耗与CO2总排放都远远小于焦炉煤气制氢;焦炉煤气制氢的三种运输方式的总能耗和CO2总排放在不同运输情况中各不相同,因此三种方式各有优势。利用这些对比结果,既能根据各种情况提供较为合适的制氢技术,又能降低其生命周期能耗、减少环境污染,具有重要意义。     

Exergy accounting of energy and materials flows in steel production systems

A life-cycle inventory (LCI) of steel based on exergy values is presented. Exergy accounting of energy and materials flows for distinct steel production processes — conventional integrated, semi-integrated and new integrated with smelt reduction — is used to calculate and compare exergy losses and efficiencies for each case. The exergy LCI provides an integrated measure of resources, products and wastes at different aggregation levels, from single unit operations and upstream production steps to steel plants and production routes. Exergy values for pollution and wastes are presented and discussed. A sensitivity analysis is performed in order to test how variations in some parameters affect the results of the total exergy accounting for the different steel production routes.     

Energy and exergy system analysis of thermal improvements of blast‐furnace plants

The blast‐furnace process dominating in the production of steel all over the world is still continuously improved due to its effectiveness (exergy efficiency is about 70%). The thermal improvement consist in an increase of the temperature of the blast and its oxygen enrichment, as well as the injection of cheaper auxiliary fuels. The main aim is to save coke because its consumption is the predominating item of the input energy both in the blast‐furnace plant and in ironworks. Besides coke also other energy carriers undergo changes, like the consumption of blast, production of the chemical energy of blast‐furnace gas, its consumption in Cowper‐stoves and by other consumers, as well as the production of electricity in the recovery turbine. These changes affect the whole energy management of ironworks due to the close connections between energy and technological processes. That means the production of steam, electricity, compressed air, tonnage oxygen, industrial water, feed water undergo changes as well. In order to determine the system changes inside the ironworks a mathematical model of the energy management of the industrial plant was applied. The results of calculations of the supply of energy carriers to ironworks can then be used to determine the cumulative energy and exergy consumption basing on average values of cumulative energy and exergy indices concerning the whole country. Such a model was also used in the system analysis of exergy losses. Copyright © 2005 John Wiley & Sons, Ltd.     

钢铁工业的节能新技术

钢铁产量连年大幅攀升,能量消耗约占钢铁生产成本的1/3左右,节约能源是钢铁企业发展的重点,采用震荡燃烧、稀释氧燃烧、直接火焰冲击燃烧、高(焦)炉喷吹废塑料以及微波、电弧和放热加热直接炼钢技术,可以有效地节能降耗,促进钢铁工业可持续发展。     

干熄焦红焦烘炉的研究与应用

本文着重阐述了干熄焦红焦烘炉的理论依据、原理、方案等，并对红焦烘炉和煤气烘炉的实施效果进行了评价比较，指出了对年修后的干熄炉红焦烘炉的优点，这对焦化干熄焦系统具有很好的推广价值。     

火落现象及其在宝钢三期焦炉上的应用实践

介绍了焦炉生产过程中出现的火落现象及其判定方法，并根据宝钢三期焦炉的实际生产情况，进行了焦炉火落时间判定的试验研究，得到了特定工况下焦炉的火落判定经验关系式。经现场实际应用，结果表明：该火落时间判定公式有较高的准确度，其结果和人工判定的火落时间最大绝对误差仅为9min，完全可以替代人工进行火落时间的一，所做工作对同类焦炉有重要的借鉴意义。     

采用燃气—蒸汽联合循环冷热电三联供能源系统在焦炉煤气制液化天然气工厂的应用研究

日益恶化的全球环境问题,要求中国天然气消费与生产保持高速增长,资源的特征决定了须从多种渠道解决天然气来源问题,焦炉煤气制液化天然气作为煤制天然气的一个路线,也将逐步地成为一个新兴的行业而快速成长与发展,国家已将此技术列入了近年重点示范推广的关键技术。在这个生产过程中冷热电能消耗都比较大,本文研究的是运用燃气轮机,进行燃气—蒸汽联合循环,实现"冷热电"三联供的典型分布式能源系统,使系统的循环效率从22～23%提高到40%以上。     

静电水处理器在鼓冷工段螺旋板换热器中的应用分析

针对螺旋板换热器易结垢、礁清洗的生产难题,采用新型表龟水处理器,对循环冷却水进行处理,实现节能降耗,由此对静电水处理器的应用前景做出展望。提出了静电防垢除垢的机理,并在微观上对其做出合理解释。     

干熄焦电气控制系统的完善与改进

叙述了本钢6号、7号焦炉干熄焦电气控制系统原设计和日常生产中存在的问题,分析了其主要原因,通过多次修改程序和调试后,采取了相关对应措施,提高了电气控制体统的稳定性,满足了干熄焦生产需要。     

焦炉煤气的余热利用

通过对焦炉煤气初冷过程的理论分析，指出焦化厂现行的单靠循环氨水喷洒集气管加初冷器的冷却过程中，能量利用的不合理，着重介绍了一项值得推广的煤气初冷余热利用系统。