Performance analysis of a syngas-fed gas turbine considering the operating limitations of its components

As the need for clean coal technology grows, research and development efforts for integrated gasification combined cycle (IGCC) plants have increased worldwide. An IGCC plant couples a gas turbine with a gasification block. Various technical issues exist in designing the entire system. Among these issues, the matching between the gas turbine and the air separation unit is especially important. In particular, the operating condition of a gas turbine in an IGCC plant may be very different from that of its original design. In this study, we analyzed the impact of the use of syngas on operating conditions of the gas turbine in an IGCC plant. We evaluated the performance of a gas turbine under operating limitations in terms of compressor surge and turbine metal temperature. Although a lower degree of integration may theoretically allow higher gas turbine power output and efficiency, it causes a reduction in compressor surge margin and overheating of the turbine metal. The turbine overheating problem may be solved using several methods, such as a reduction in the firing temperature or an increase in the turbine cooling air. The latter yields a much smaller performance penalty. To achieve an acceptable margin for the compressor surge, either further reduction in the firing temperature or further increase in the coolant is required. Ventilation of some of the nitrogen generated by the air separation unit, i.e., a reduction of the nitrogen supply to the combustor, is another option. Coolant modulation yields the lowest performance penalty. Reduction of the nitrogen supply provides much greater system power output than control of the firing temperature. For nitrogen flow and firing temperature controls, there are optimal levels of integration degrees in terms of net system power output and efficiency.     

Modelling and performance analysis of an integrated plasma gasification combined cycle (IPGCC) power plant

The waste management is become a very crucial issue in many countries, due to the ever-increasing amount of waste material, both domiciliary and industrial, generated. The main strategies for the waste management are the increase of material recovery (MR) which can reduce the landfill disposal, the improvement of energy recovery (ER) from waste and the minimization of the environmental impact.Recent studies have focused on an innovative technology, the plasma gasification, that has been demonstrated as one of the most effective and environmentally friendly methods for solid waste treatment and energy utilization.In this paper, a plasma gasification process based on plasma torch technology has been investigated by developing a thermochemical model (EPJ, EquiPlasmaJet) able to estimate both the syngas composition and the energy required for the gasification reactions. The EPJ model has been employed to predict the syngas composition and the energy balance of a RDF (refuse derived fuel) plasma arc gasification reactor using air as plasma gas, and, in order to define the optimal operating conditions three different configurations have been investigated.Results show that, in the better plant solution, the plasma gasification efficiency is 69.1% (LHV) and the lower heating value of the syngas generated is about 9 MJ/kg. Furthermore in order to evaluate the suitability of this technology for energy recovery from solid wastes, the integration of the optimum plasma gasification system (PGS) with a gas turbine combined cycle (GTCC) has been analysed and the performance of the resulting integrated plasma gasification combined cycle (IPGCC) has been evaluated. The system efficiency (31% LHV) is very high in comparison with the efficiency of conventional technologies based on waste incineration (20%).     

煤的部分空气气化联合循环发电系统特性研究

煤的部分空气气化联合循环发电是一种把煤气化技术和循环流化床技术结合起来的洁净煤发电技术。文章通过对三种方案的计算，得出了碳的转化率与运行温度、煤气热值、气化效率、系统效率之间的关系，证实了碳的转化率对系统运行有重要的影响，同时和其他气化方式下联合循环发电系统进行比较分析，证实煤的空气部分气化联合循环系统是一高效低污染、技术简单、投资小、见效快的发电系统。     

Thermodynamic evaluation of solar integration into a natural gas combined cycle power plant

The term integrated solar combined-cycle (ISCC) has been used to define the combination of solar thermal energy into a natural gas combined-cycle (NGCC) power plant. Based on a detailed thermodynamic cycle model for a reference ISCC plant, the impact of solar addition is thoroughly evaluated for a wide range of input parameters such as solar thermal input and ambient temperature. It is shown that solar hybridization into an NGCC plant may give rise to a substantial benefit from a thermodynamic point of view. The work here also indicates that a significant solar contribution may be achieved in an ISCC plant, thus implying substantial fuel savings and environmental benefits.     

联合循环参数和系统结构优化研究

研究了如何提高余热锅炉型三压再热联合循环系统的效率,应用分析的方法建立了系统效率数学模型,以联合循环系统效率最高作为系统性能的评判标准。在亚临界范围内,对余热锅炉的蒸汽参数进行了优化;针对余热锅炉进气温度对余热锅炉性能的影响进行分析,在此基础上提出燃气轮机排气部分回热利用,并研究了回热利用对联合循环效率的影响。计算结果表明:经余热锅炉优化和排气部分回热利用,在基本负荷下,PG9351FA机组的联合循环热效率可提高1.33%;在75%和50%的负荷下,效率分别提高2.11%和4.17%;而具有再热的GT26机组热效率高达60.73%。     

利用燃气—蒸汽联合循环改造老电厂

利用燃气－蒸汽联合循环对老电厂进行改造,能够提高能源的综合使用率,降低能耗,并有效利用老电厂的现有设备,可以减少投资并见效快,文章对利用燃气－蒸汽联合循环对老电厂进行改造的主要方式和热效率进行了分析。     

Effect of supplementary firing options on cycle performance and CO2 emissions of an IGCC power generation system

Supplementary firing is adopted in combined‐cycle power plants to reheat low‐temperature gas turbine exhaust before entering into the heat recovery steam generator. In an effort to identify suitable supplementary firing options in an integrated gasification combined‐cycle (IGCC) power plant configuration, so as to use coal effectively, the performance is compared for three different supplementary firing options. The comparison identifies the better of the supplementary firing options based on higher efficiency and work output per unit mass of coal and lower CO₂ emissions. The three supplementary firing options with the corresponding fuel used for the supplementary firing are: (i) partial gasification with char, (ii) full gasification with coal and (iii) full gasification with syngas. The performance of the IGCC system with these three options is compared with an option of the IGCC system without supplementary firing. Each supplementary firing option also involves pre‐heating of the air entering the gas turbine combustion chamber in the gas cycle and reheating of the low‐pressure steam in the steam cycle. The effects on coal consumption and CO₂ emissions are analysed by varying the operating conditions such as pressure ratio, gas turbine inlet temperature, air pre‐heat and supplementary firing temperature. The results indicate that more work output is produced per unit mass of coal when there is no supplementary firing. Among the supplementary firing options, the full gasification with syngas option produces the highest work output per unit mass of coal, and the partial gasification with char option emits the lowest amount of CO₂ per unit mass of coal. Based on the analysis, the most advantageous option for low specific coal consumption and CO₂ emissions is the supplementary firing case having full gasification with syngas as the fuel. Copyright © 2008 John Wiley & Sons, Ltd.     

4MW级生物质气化发电示范工程的设计研究

介绍了我国4MW级的生物质气化整体联合循环发电示范工程的设计特点。该工艺中使用了中温静电除尘、焦油裂解装置和显热回收系统，预计投运后，将会使生物质的气化效率提高、可燃气中焦油含量减少以及系统效率得以提高，为我国生物质能的开发与运用开辟了广阔的前景。     

Analysis of energy-conversion processes in gas–steam power-plants integrated with coal gasification

The paper presents the complex energy analysis of technological systems of gas–steam power plants integrated with coal gasification. The bases of the performed energy analyses are the elaborate mathematical models describing the behaviour of main elements of the gas-steam power plants integrated with coal gasification, such as the gas generator, raw-gas cooler with the gas desulphurisation system, compressor, combustion chamber, gas turbine, heat-recovery steam-generator and steam-turbine cycle. The influence of coal-gasification technology, coal type, gasifying medium, fuel-desulphurisation technology and gas-turbine design on the efficiency of electric-energy generation were taken into account.     

对9FA燃气轮机联合循环机组性能试验的思考

对9FA燃机联合循环性能试验中的一些问题进行了分析,如性能的修正、余热锅炉的性能考核、责任分摊等,并给出了作者的看法,供同行参考。     

Analysis of a Coal Fired Combined Cycle with Carried—Heat Gasification

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Comparative exergoeconomic analyses of the integration of biomass gasification and a gas turbine power plant with and without fogging inlet cooling

Inlet cooling is effective for mitigating the decrease in gas turbine performance during hot and humid summer periods when electrical power demands peak, and steam injection, using steam raised from the turbine exhaust gases in a heat recovery steam generator, is an effective technique for utilizing the hot turbine exhaust gases. Biomass gasification can be integrated with a gas turbine cycle to provide efficient, clean power generation. In the present paper, a gas turbine cycle with fog cooling and steam injection, and integrated with biomass gasification, is proposed and analyzed with energy, exergy and exergoeconomic analyses. The thermodynamic analyses show that increasing the compressor pressure ratio and the gas turbine inlet temperature raises the energy and exergy efficiencies. On the component level, the gas turbine is determined to have the highest exergy efficiency and the combustor the lowest. The exergoeconomic analysis reveals that the proposed cycle has a lower total unit product cost than a similar plant fired by natural gas. However, the relative cost difference and exergoeconomic factor is higher for the proposed cycle than the natural gas fired plant, indicating that the proposed cycle is more costly for producing electricity despite its lower product cost and environmental impact.     

不同运行方式对联合循环电站部分负荷性能的影响

计算并分析比较了不同调节方式对部分负荷运行时某燃气－蒸汽联合循环电站各个组成部分及总体性能的影响。     

大型联合循环机组关键问题的探讨

随着“西气东输”及“引进液化天然气”工程的实施,我国将建设一批大型燃气—蒸汽联合循环电厂。本文就大型燃气—蒸汽联合循环机组的效率、余热锅炉型式、轴系布置、进气冷却等关键技术问题进行了探讨。     

整体煤气化联合循环电站的模拟和经济性分析

用GTPRO软件模拟了整体煤气化联合循环（IGCC）和燃气轮机联合循环（GTCC）电站,并进行经济性分析.分析内容包括煤价、电价和贷款利率对IGCC电站经济性的影响;IGCC电站和GTCC电站的经济性对比,特别是对天然气价格在其中的影响进行了分析,得出了一些有重要参考价值的定量结果.     

联合循环机组调节系统参数测试方法研究

发电机组参数测试试验是机组并网安全评定项目之一,为电网中长期稳定性分析提供了依据。本文在燃气轮机各部分控制系统分析的基础上,对某联合循环机组的调节系统建立模型,该模型说明,采用适当的方法可以进行联合循环机组的参数辨识。     

9FA型燃气轮机联合循环性能研究

1引言西气东输工程促进了沿线燃气轮机联合循环电厂的建设,减轻了中东部地区的环境排放压力。燃气轮机联合循环发电系统高效低污染、启停迅速、调峰能力强。西气东输管道沿线有25台F级燃气轮机联合循环机组,其中GE公司9FA型燃气轮机联合循环发电机组13台。如何保证系统的稳定安     

燃气-蒸汽联合循环电站机组配置及选型分析

对联合循环电站燃气轮机选型、蒸汽系统的选择、余热锅炉和汽轮机选型、机组轴系配置、动力岛布置、主要辅助设备的选择等方面进行了分析研究,为联合循环电站的设计和研究方向提供了建议。     

Monitoring of the thermoeconomic performance in an actual combined cycle power plant bottoming cycle

This paper presents a research project carried out by TPG (Thermochemical Power Group) of University of Genoa to develop innovative monitoring and diagnostics procedures and software tools for software-aided maintenance and customer support. This work is concerned with preliminary outcomes regarding the thermoeconomic monitoring of the bottoming cycle of a combined cycle power plant, using real historical data. The software is able to calculate functional exergy flows (y), their related costs (c) (using the plant functional diagram); after that non dimensional parameters for the characteristic exergonomic indexes (Δc, Δc*, Δk*) are determined.     

Performance improvement of the combined cycle power plant by intake air cooling using an absorption chiller

This paper studies how to improve the capacity of the combined cycle (CC) power plant which has been operated for 8 years. The most popular way is to lower intake air temperature to around 15 °C (ISO) and 100% RH before entering the air compressor of a gas turbine (GT). Thailand has 3 seasons: winter, summer and rainy season. According to 2003 Bangkok monthly weather data, all year ambient temperature is higher than 15 °C. This research proposes a steam absorption chiller (AC) to cool intake air to the desired temperature level. It could increase the power output of a GT by about 10.6% and the CC power plant by around 6.24% annually. In economic analysis, the payback period will be about 3.81 years, internal rate of return 40%, and net present value 19.44 MUS$.