Energy conservation in the refinery by utilizing reformed fuel gas and furnace flue gases

Decrease of fuel supplies and cost increases make it vital for industries, especially energy intensive ones, to consider conserving available sources and convert losses into sources of energy.In this paper, a gas turbine-based cogeneration system is suggested to utilize a refinery's reformer gas in the gas turbine, and furnaces flue gases together with the engine exhaust gases in a heat recovery steam generator, HRSG. This is proposed as an alternative to the currently used system where the gas turbine and the steam generator are used separately. Operating variables comprising compressor pressure ratio and turbine inlet temperature are varied widely to evaluate performance; namely power, SFC, overall efficiency and annual fuel savings at design and off-design loading conditions using a dedicated computer program.Results show that the proposed system offers 100% higher overall efficiency and $5.25 million annual fuel saving for a 12 MW_e gas turbine.     

Refuse-fired,pressurized, fluidized-bed combustion combined cycle analysis

Use of pressurized, fluidized-bed combustion (PFBC) has given a new opportunity to use municipal refuse as fuel for combined gas and steam power cycles keeping the pollutants of sulphur and nitrogen oxides to a minimum at reduced capital cost.In combined gas and steam power cycles, the heat energy in the exhaust gases of a simple gas turbine cycle is used to generate steam in a waste-heat boiler and the generated steam is used in the steam turbine for power generation.The effects of gas turbine pressure ratio and inlet temperature on the main parameters of refuse-fired, pressurized, fluidized-bed combustion combined cycles are determined.The results indicate a maximum combined cycle thermal efficiency and work output at a possible range of optimum pressure ratios between 10 and 12 for a range of gas turbine inlet temperatures of 750–1000°C.     

The gas turbine-jet pump coupling in cogeneration plants

When a steam driven jet pump is coupled to a gas turbine it can decrease the exhaust total pressure of the turbine and thus increase its output and the gas turbine thermal efficiency. If the steam is generated in a waste heat recovery the thermal efficiency of the engine may increase by 2–3%. The present paper studies the gas turbine-jet pump coupling, at various partial loads, by incorporating the long exhaust diffuser as a water preheater. In addition, additional firing may be introduced at the boiler inlet to keep the temperatures of the boiler constant. The results indicate that the efficiency of the gas turbine increases by 3–4% at optimum conditions.     

Waste heat recovery of dura (Iraq) oil refinery and alternative cogeneration energy plant

The first part of this paper presents a waste heat recovery scheme for the Dura (Baghdad, Iraq) oil refinery energy plant. Both the wasted heat of the process return condensate and the flue gases are utilized for low temperature feedwater and fuel heating. The steam saved, both from the main steam line and turbine extraction system, was found to increase the steam and plant overall efficiency by 18%.An alternative cogeneration energy plant is presented in the second part of this study. The proposed plant utilizes the gas turbine exhaust, in conjunction with a heat recovery boiler, to produce the process steam requirement. With this alternative plant, the overall efficiency increases by 31.6%, while the steam efficiency increases by 19%. The outstanding features and advantages of the proposed plants are highlighted.     

Combined cycles with gas turbine engines

Simple cycle gas turbine engines suffer from limited efficiencies and consequential dominance of fuel prices on generation costs. Combined cycles, however, exploit the waste heat from exhaust gases to boost power output, resulting in overall efficiencies around 50%, which are significantly above those of steam power plants. This paper reviews various types of combined cycles, including repowering, integrated gasification and other advanced systems.     

Gas turbine waste heat recovery distillation system

This article presents a method for improving the gas turbine's performance through an efficient utilization of the waste heat in a distillation system with a special arrangement. This consists of two trains of VTE/MEB connected to increase the fresh water produced. Exhaust gases from the gas turbine are used in a multi-temperature level heat recovery system with five feed heaters, and gases are released to ambient at 130°C. Distillation top train has nine effects and evaporation range from 130 to 82°C while the bottom train has six effects with evaporation range from 76 to 46°C and is supplied with the steam leaves the last effect in the top train.Thermal analysis using a 32.67 MW gas turbine showed that the present arrangement can produce 3.2 million gallons per day (mgd) of fresh water with more than 4 g/kWh at a performance ratio (PR) of 8.8. This is 34% more than that produced in an existing gas-turbine distillation combination and 14% more than that expected from a reverse osmosis plant driven by a bottoming Rankine power cycle.     

甲醇--动力联产系统热功转换过程分析

在联产系统能量和物质转换过程模拟和分析的基础上,重点研究了热功转换过程及其与甲醇合成过程的相互影响.得到部分联产率对系统输出功、甲醇合成压缩机耗功、甲醇产量、合成塔副产蒸汽的影响.并对比了动力独立生产系统和部分联产系统供电效率.     

The effect of the operating parameters of heat recovery steam generators on combined cycle/sea-water desalination plant performance

Combined gas/steam turbine cycle plants have been proposed for cogeneration of electricity and process steam. Examples are combined-cycle power plants coupled with sea-water desalination, district heating plants, chemical industries, etc. In combined heat and power plants, the gas turbine exhaust heat is utilized through the use of heat recovery steam generators (HRSG's). As a result, these waste heat generators (boilers), whether fired or unfired, control the performance of the combined plant lower side (bottoming cycle). Moreover, any changes made in the HRSG operating parameters (i.e. the pinch point, approach temperature, first and second stage pressures, and mass ratios) can greatly affect the HRSG performance and will eventually affect the overall combined plant performance. This paper presents a method to predict the performance of the heat recovery steam generators (HRSG)/steam bottoming cycle combined with sea-water desalination plant at various steam and exhaust gas conditions.     

A case study of cogeneration for Jeddah and Yanbu petromin refineries in Saudi Arabia

The Petromin refineries in Jeddah and Yanbu, Saudi Arabia produce power and process steam separately. The Jeddah refinery gas turbines that have an installed capacity of 88 MW, run at less than 50% utilization factor. The refinery demand of steam is 70–120 tons h⁻¹.The electric power demand of Yanbu refinery is supplied by The Royal Commission of Yanbu at a rate of 16–25 MW. The steam consumption is 68 tons h⁻¹. Data were collected for the performance and requirement for both plants. An integrated system for cogeneration is proposed which consists of a gas turbine, heat recovery steam generator equipped with a supplementary duct burner and economizer. The thermal and economical analyses have proved the feasibility of the proposed system with payback periods of 23 and 36 months for Jeddah and Yanbu refineries, respectively. However, the payback period for Jeddah refinery can be reduced to 15 months if the utilization factor is improved, and the excess power generated by the gas turbines is connected to the public utility grid. In fact, it is worth mentioning that the present study is considered the first to be carried out in Saudi Arabia; more studies and investigations could lead to tremendous saving in the fuel consumption in this country.     

氨水工质功冷联供循环内中温中压能的回收

本文提出两种采用引射器回收氨水工质功冷联供循环内的中温中压能量的改进方案,即通过回收热源能量将中温中压稀氨水工质加热至过热蒸汽状态后作为引射器工作工质分别用于:方案一,引射透平排汽以降低背压;方案二,引射蒸发器出口工质以降低蒸发压力.计算表明相同耗能下,相对于基础循环,方案一的净输出功提高0.9%、(火用)效率提高了0.8%;方案二的冷(火用)输出提高了11.1%,(火用)效率提高了0.7%,从而为有效回收系统内部能量提供了新的途径.     

新型多能源互补系统的热力经济性分析

本文对SOLRGT系统（一种新型的中低温太阳能与化石燃料互补的动力系统）进行了热力经济性分析。该系统基于化学回热循环,通过中低温太阳能品位的间接提升、与先进燃气轮机的集成,实现中低温太阳能的高效、低成本热功转换以及和化石燃料的综合梯级利用。本文将其与同等输入下的两种单输入发电系统进行对比分析,研究表明：基本工况下,SO...     

排气全燃型联合循环设计点性能简明估计公式

排气全燃型联合循环设计点性能简明估计公式蔡睿贤（中国科学院工程热物理研究所北京１０Ｏ０８０）关键词：排气全燃型联合循环，热力分析主要符号表Ｈｕ燃料热值Ｌ燃料理论空气量ｌ比功Ｐ单位能量价格Ｒ燃气轮机与蒸汽轮机的功率比α过量空气系数β摩尔燃料系数△增量η...     

燃气轮机合成气燃烧室燃料气加湿实验研究

本文针对一种燃用合成气的40MW级燃气轮机燃烧室,进行了该型燃烧室的全压燃料气蒸汽加湿试验研究,得到了燃烧室在基本负荷下随加湿量变化污染物排放、燃烧室内动态压力、火焰筒壁面温度等重要参数的变化规律,分析了燃料气加湿对燃气轮机总体性能、污染物排放、火焰筒壁温及燃烧稳定性方面的影响,探讨了燃料气加湿对合成气燃烧中Nox生成的机理性作用. 研究表明燃料气加湿是降低燃用合成气的燃气轮机氮氧化物排放的有效方式.     

冷热电联产系统的评价准则

本文通过对以燃气轮机回热循环为动力系统的冷热电联产系统进行热力学分析,对几种常用的评价准则进行了比较。通过分析,认为能量利用系数将冷、热、电等各股能量等价看待,(火用)效率过分看重能量的作功能力,折合发电效率过分关注冷、热能的输出,均不适于冷热电联产系统的评价;节能率反映的是输入能量的使用情况,经济(火用)效率在某种程度上是经济性的表现,比较适于冷热电联产系统的评价。研究中发现,燃气轮机温比有利于系统性能的提高,但针对不同的目标有不同的最佳压比;在节能率的使用中需要明确参照系统的性能。     

环境温度对燃气轮机功热并供装置及联合循环变工况性能的影响

采用动力机械变工况性能解析分析方法,研究了大气温度变化对燃气轮机功热并供和联合循环装置性能影响．指出燃气轮机在带有余热利用的条件下,大气温度的影响明显减弱,并对不同燃气轮机设计参数和蒸汽设计参数影响做了分析比较。     

Thermal performance of waste-heat recuperator with heat pipes for thermal power station

Analytical studies were conducted to investigate the thermal performance of a heat pipe heat exchanger to recover thermal energy from exhaust hot gas from a boiler, in order to replace a conventional heat recovery system (Ljungstrom) in the steam power plant.     

燃气轮机合成气燃烧室中燃烧噪声的现场测试与分析

燃气轮机的燃烧噪声是反映燃烧室燃烧稳定性的主要参数.本文对国内某座煤基IGCC示范电站的40 MW级燃气轮机在诸多运行条件下的燃烧噪声进行了现场测试,分析了气液双燃料喷嘴在燃烧轻柴油、燃烧合成气以及油气切换过程中燃烧室的燃烧噪声,另外分析了合成气掺烧驰放气与合成气加湿对燃烧稳定性的影响.结果表明:合成气燃烧室在油气切换过程中燃烧噪声会增加,但距离振荡燃烧的阈值仍有很大的裕度;烧合成气时随着燃气轮机功率增加燃烧噪声降低;合成气加湿时随着蒸汽流量增加污染物NOx排放显著降低,并且燃烧噪声也有降低的趋势.     

Thermodynamic Analysis and Optimization of a Novel Power-Water Cogeneration System for Waste Heat Recovery of Gas Turbine

A power-water cogeneration system based on a supercritical carbon dioxide Brayton cycle (SCBC) and reverse osmosis (RO) unit is proposed and analyzed in this paper to recover the waste heat of a gas turbine. In order to improve the system performance, the power generated by SCBC is used to drive the RO unit and the waste heat of SCBC is used to preheat the feed seawater of the RO unit. In particular, a dual-stage cooler is employed to elevate the preheating temperature as much as possible. The proposed system is simulated and discussed based on the detailed thermodynamic models. According to the results of parametric analysis, the exergy efficiency of SCBC first increases and then decreases as the turbine inlet temperature and split ratio increase. The performance of the RO unit is improved as the preheating temperature rises. Finally, an optimal exergy efficiency of 52.88% can be achieved according to the single-objective optimization results.     

第二代AFBC—CC热力性能初探

第二代ＡＦＢＣ—ＣＣ热力性能初探张娜，蔡睿贤，林汝谋（中国科学院工程热物理研究所）关键词常压流化床，燃煤联合循环，效率，功比符号表Ｄ总压恢复系数Ｔｅ余热锅炉排烟温度Ｂ燃烧室Ｇ流量△增量Ｃ压气机Ｈ焓η效率ｃｃ联合循环Ｈｕ煤气热值π压比ｄ燃气透平出口Ｎ功...     

Enhancing gas turbine performance by intake air cooling using an absorption chiller

The performance of gas turbines, operated either as a simple cycle or a combined cycle, is critically constrained by the prevailing ambient temperature, particularly in arid and tropical climates. This paper investigates the option of cooling the intake air to the compressor of the gas-turbine system using an absorption chiller in order to increase the gas turbine capacity. High-temperature waste heat from the exhaust gas may be utilized to produce steam in a recovery boiler. Part of the steam produced could then be used to drive a lithium-bromide double-effect absorption chiller which in turn could cool the incoming air. An analysis carried out by taking the weather data of Bangkok (Thailand) indicates that reducing the temperature from ambient condition to 15°C could help to increase the instantaneous power output between 8 and 13%. As an outcome, as much as 11% additional electricity could be generated from the same gas turbine power plant.A simple economic assessment indicates that the proposed scheme will require a minimal investment as compared to the commissioning cost of a new gas turbine unit to meet the corresponding capacity increment. The latter will need nearly four times higher initial cost than the amount estimated for the proposed scheme. Thus, implementation of such a system would significantly abate the negative impact of the ambient temperature, while providing an economically and environmentally attractive option for energy producers in most developing nations of the world which are located in arid and tropical zones.