日本炼油公司面临的挑战

本文回顾了2001年日本石油市场的情况,通过对未来市场的预测,就日本炼油公司面临的挑战进行了分析。     

炼油蒸汽管网模拟与监测管理系统

介绍了利用计算机技术建立的炼油厂蒸汽管网模拟与监测管理系统。通过该系统能在线监测整个管网系统，以保证管网优化节能运行。     

炼厂瓦斯气的回收利用及自动控制

简要介绍了对炼厂瓦斯气进行回收利用的手段和设备,并对其中的关键技术－火炬设施的自动控制作了较为全面的分析。指出该技术无论是从环保安全还是从节能降耗方面,均具有极佳的推广应用价值。     

Modelling of biomass gasifier and microturbine for the olive oil industry

The olive oil industry generates several solid wastes. Among these residues are olive tree leaves, prunings, and dried olive pomace (orujillo) from the extraction process. These renewable energy sources can be used for heat and power production. The aim of this paper consists of modelling and simulation of a small‐scale combined heat and power (CHP) plant (fuelled with olive industry wastes) incorporating a downdraft gasifier, gas cleaning and cooling subsystem, and a microturbine as the power generation unit. The gasifier was modelled with thermodynamic equilibrium calculations (fixed bed type, stratified and with an open top). This gasifier operates at atmospheric pressure with a reaction temperature about 800°C. Simulation results (biomass consumption, gasification efficiency, rated gas flow, calorific value, gas composition, etc.) are compared with a real gasification technology. The product gas obtained has a low heating value (4.8–5.0 MJ Nm^?3) and the CHP system provides 30 kW_e and 60 kW_th. High system overall CHP efficiencies around 50% are achievable with such a system. The proposed system has been modelled using Cycle‐Tempo software^®. Copyright © 2010 John Wiley & Sons, Ltd.     

Dust explosion of oil shale and olive cake solid fuels: a comparison study

This paper investigates the inhibition of oil shale and olive cake dust explosions when they are used as an alternative source of fuel. Special emphasis was given to the effect of particle size of the same material on the maximum permissible oxygen concentration to prevent dust explosion for different concentrations using nitrogen as the diluent gas. It was found that olive cake is ignited more easily than oil shale all over the range of particle sizes and dust concentration. Tests on different particle sizes were carried out, and it was found that the maximum permissible oxygen concentration for a given dust concentration increases with increasing the particle size for both oil shale and olive cake. Copyright © 2005 John Wiley & Sons, Ltd.     

管道热输原油过程的(火用)传递分析

在求解热油管道温度场、压力场的基础上,给出了其包括压Yong、压Yong流密度、压Yong传递系数及其常影响因子在内的Yong传递分析指标。对大庆油田某热油管道的应用数值模拟表明：Yong传递分析不仅可对管道输送过程主导势场Yong传递的时空变化规律进行描述,对温度场、压力场二基本势场的协同作用机制作以合理解释,还提出了诸如增大压力可有效提高输油管道的压Yong传递系数等改进输送过程的技术途径。     

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.     

生物质的热裂解与热解油的精制

生物质能属于可再生能源，其利用符合社会可持续发展的原则。生物质在中等温度下(约500℃)热裂解主要得到热解油。介绍了温度对热裂解过程的影响、热解油——水的二元相图、热裂解过程的机理和热解油的特性，综述了催化剂种类，溶剂等对热解油催化裂解的影响。结果表明，催化剂H-ZSM-5的脱氧效果最好，以四氢萘为溶剂时，精制油的收率大幅提高，达39．4％。     

Performance assessment and optimization of industrial pasta drying

Drying is a high‐energy‐intensive operation and an important step in the pasta production. In this study, exergy analysis of a four‐step drying system in a farfalle pasta production line using actual operational data obtained from a plant located in Izmir, Turkey, was performed. Exergy loss rates, evaporation rates, exergy efficiencies, and improvement in potential rates for each dryer section were determined in this drying system. The exergy efficiency values varied between 0.25% and 5.27% from the predrying to the final drying section. The exergy efficiency value for the entire drying system was calculated to be 2.96%, and the highest exergetic improvement in potential rate was 165.54 kW for the first dryer section. Copyright © 2013 John Wiley & Sons, Ltd.     

Thermodynamic analysis of reheat cycle steam power plants

In this study, a thermodynamic analysis of a Rankine cycle reheat steam power plant is conducted, in terms of the first law of thermodynamic analysis (i.e. energy analysis) and the second law analysis (i.e. exergy analysis), using a spreadsheet calculation technique. The energy and exergy efficiencies are studied as 120 cases for different system parameters such as boiler temperature, boiler pressure, mass fraction ratio and work output. The temperature and pressure values are selected in the range between 400 and 590°C, and 10 and 15 MPa, being consistent with the actual values. The calculated energy and exergy efficiencies are compared with the actual data and the literature work, and good agreement is found. The possibilities to further improve the plant efficiency and hence reduce the inefficiencies are identified and exploited. The results show how exergy analysis can help to make optimum design decisions in a logical manner. Copyright © 2001 John Wiley & Sons, Ltd.     

船舶蒸汽动力装置燃油压力调节系统的性能仿真与改进建议

由于船舶蒸汽动力装置燃油系统工作压力较高，且变化剧烈，容易发生管路密封垫片处崩出等事故，这将直接导致该动力单元瘫痪。针对该类故障，提出改进建议，并应用MATLAB／Simulink仿真工具对燃油系统进行定性、定量分析，对所提出的改进方法进行比较验证。     

Exergy analysis of a coal‐based 210 MW thermal power plant

In the present work, exergy analysis of a coal‐based thermal power plant is done using the design data from a 210 MW thermal power plant under operation in India. The entire plant cycle is split up into three zones for the analysis: (1) only the turbo‐generator with its inlets and outlets, (2) turbo‐generator, condenser, feed pumps and the regenerative heaters, (3) the entire cycle with boiler, turbo‐generator, condenser, feed pumps, regenerative heaters and the plant auxiliaries. It helps to find out the contributions of different parts of the plant towards exergy destruction. The exergy efficiency is calculated using the operating data from the plant at different conditions, viz. at different loads, different condenser pressures, with and without regenerative heaters and with different settings of the turbine governing. The load variation is studied with the data at 100, 75, 60 and 40% of full load. Effects of two different condenser pressures, i.e. 76 and 89 mmHg (abs.), are studied. Effect of regeneration on exergy efficiency is studied by successively removing the high pressure regenerative heaters out of operation. The turbine governing system has been kept at constant pressure and sliding pressure modes to study their effects. It is observed that the major source of irreversibility in the power cycle is the boiler, which contributes to an exergy destruction of the order of 60%. Part load operation increases the irreversibilities in the cycle and the effect is more pronounced with the reduction of the load. Increase in the condenser back pressure decreases the exergy efficiency. Successive withdrawal of the high pressure heaters show a gradual increment in the exergy efficiency for the control volume excluding the boiler, while a decrease in exergy efficiency when the whole plant including the boiler is considered. Keeping the main steam pressure before the turbine control valves in sliding mode improves the exergy efficiencies in case of part load operation. Copyright © 2006 John Wiley & Sons, Ltd.     

Challenges and technological opportunities for the oil refining industry: A Brazilian refinery case

The worldwide oil refining industry currently faces strong challenges related to uncertainties about future feedstock and characteristics of oil products. These challenges favor two main strategies for the sector: the first strategy is increasing refinery complexity and versatility; the second is integrating the refining and petrochemical industries, adding value to the crude oil while guaranteeing market share to premium oil products. Both strategies aim at increasing production of highly specified oil products, simultaneously reducing the environmental impacts of the refining industry. This paper analyses the case of a Brazilian refinery, Gabriel Passos Refinery (REGAP), by proposing additional investments to alter and/or expand its current production scheme. All the proposed options present relatively low investment rates of return. However, investments in a hydrocracking based configuration with a gasification unit providing hydrogen and power can further improve the operational profitability, due to reduced natural gas consumption.     

Abatement costs of CO2 emissions in the Brazilian oil refining sector

This study aims at estimating the abatement costs of CO₂ emissions of the Brazilian oil refining sector. For greenfield refineries that will be built until 2030, mitigation options include the modification of refining schemes and efficiency gains in processing units. For existing refineries and those already under construction, only mitigation options based on efficiency gains in processing units are evaluated. The abatement cost of each mitigation option was determined on the basis of incremental costs compared with a reference scenario. Two discount rates were applied: one adopted by the Brazil’s government official long term plan (8% p.a.), and another typically adopted by the private oil sector (15% p.a.). Findings indicate that refineries face high abatement costs. The cost of changing the processing scheme of greenfield plants reaches US$100/tCO₂ at 15% p.a. discount rate. Even at 8% p.a. discount rate the abatement cost is higher than US$50/tCO₂. The most promising alternative is thermal energy management, whose abatement cost equals US$20/tCO₂ at 8% p.a. discount rate. However, private investors perceive this option at US$80/tCO₂, which is still high. This difference in cost indicates the need for public policies for promoting carbon mitigation measures in Brazilian oil refineries.     

中冷回热布雷顿热电联产装置的火用性能分析

建立了恒温热源内可逆中冷回热布雷顿热电联产装置模型,基于火用分析的观点,用有限时间热力学理论和方法研究了装置的性能,导出了无量纲火用输出率和火用效率的解析式。讨论了总压比给定和总压比变化两种情形,优化了中间压比和总压比,通过数值计算分析了回热度、中冷度和高温侧热源温度与环境温度之比等参数对装置一般性能和最优性能的影响,研究了火用输出率和火用效率之间的关系,其特性关系为扭叶型。最后发现分别存在最佳的用户侧温度使火用输出率和火用效率取得双重最大值。     

Performance analysis of gas liquefaction cycles

Relations are developed for first‐ and second‐law analyses of the simple Linde–Hampson cycle used in gas liquefaction systems. An expression for the minimum work requirement, which is applicable to any gas liquefaction system, is developed with the help of a Carnot refrigerator. It is shown that the minimum work depends only on the properties of the incoming and outgoing gas streams and the environment temperature. Numerical calculations are performed to obtain the performance parameters of different gases while parametric studies are done to investigate the effects of liquefaction and inlet gas temperatures on various first‐ and second‐law performance parameters. As the liquefaction temperature increases and the inlet gas temperature decreases, the liquefied mass fraction, the coefficient of performance (COP) and the exergy efficiency increase while actual and reversible work consumptions decrease. The exergy efficiency values appear to be low, indicating significant potential exists for improving efficiency and thus decreasing the required work consumption for a specified amount of liquefaction. Copyright © 2007 John Wiley & Sons, Ltd.     

Energy–exergy analysis and modernization suggestions for a combined‐cycle power plant

Energy and exergy analysis were carried out for a combined‐cycle power plant by using the data taken from its units in operation to analyse a complex energy system more thoroughly and to identify the potential for improving efficiency of the system. In this context, energy and exergy fluxes at the inlet and the exit of the devices in one of the power plant main units as well as the energy and exergy losses were determined. The results show that combustion chambers, gas turbines and heat recovery steam generators (HRSG) are the main sources of irreversibilities representing more than 85% of the overall exergy losses. Some constructive and thermal suggestions for these devices have been made to improve the efficiency of the system. Copyright © 2005 John Wiley & Sons, Ltd.     

基于_分析的发电厂改造方法研究

根据分析理论,把锅炉、汽轮机及发电厂热力系统作为一个整体,通过对发电厂各环节进行分析找到具体损失环节并对具体位置提出改造方案,是发电厂改造的一种新方法。以某超超临界机组为例,运用分析理论找到损失环节,找到二次风温及给水温度对锅炉系统及电厂热力系统影响的关系,通过增加一级高压加热器提高给水温度,同时在保证锅炉排烟温度不变的前提下适当地提高二次风温,分析在给水温度及二次风温的双重作用下,锅炉乃至整个机组性能的变化。结果表明,当给水温度由299.5℃升高至322℃时,二次风温由327.8℃升高至360℃,锅炉系统传热损失由3 443 kJ/kg降低至3 254 kJ/kg,燃烧环节损失由6 204 kJ/kg降低至6 158 kJ/kg,锅炉效率由54.15%升高至54.45%,机组目的效率由42%升高至46.7%。     

Performance enhancement in coal fired thermal power plants. Part I: boilers

This paper presents the results of the performance enhancement study in 22 coal fired thermal power stations of capacities 30–500 MW. The efficiencies and performance indices of the equipment are evaluated which then leads to the performance evaluation route—operational optimization, simple modification of equipment or renovation. The generic problems associated with design, operation and fuel inputs is investigated and appropriate solutions are suggested to improve the boiler efficiency levels from 71–86% to 86–87% immediately and 89–90% on a long term (5–10 yr) basis. A large volume of design and operating data has been analysed and presented in the form of curve fits for computer simulation of the performance of boilers for high ash coals. Copyright © 1999 John Wiley & Sons, Ltd.     

Performance and emission analysis of compression ignition engine using biodiesels from Acid oil,Mahua oil,and Castor oil

Research on and use of biodiesels for engines is growing continuously in the present era. Compression ignition (CI) engine performance for biodiesels of blends B20 from Acid oil, Mahua oil, and Castor oil is experimentally investigated. The engine performance analysis in the form of brake‐specific fuel consumption, brake‐specific energy consumption, brake thermal efficiency (BTE), exhaust gas temperature (EGT), and air fuel ratio are compared with diesel as base fuel. Emission characteristics like CO, CO₂, NOx, and opacity are comparatively studied in detail for the considered biodiesels. The entire study is compared with the performance of engine when pure diesel is chosen as fuel. From the complete analysis it was observed that the BTE was higher for Acid oil and Mahua oil among the biodiesels used. And regarding CO emissions, Mahua oil showed lower effect than other biodiesels. Upto 6% increase in EGT of Mahua oil was obtained at no load and for other loads the percent reduced. For all the biodiesels the % enhancement in Co, CO₂, and NOx was more than 60% at highest load compared with diesel.