Assessment of Site Parameters and Heat Recovery Characteristics on Combined Cycle Performance in an Equatorial Environment

This paper investigates the effects of site based parameters such as ambient temperature, humidity, altitude and heat transfer characteristic of a dual pressure heat recovery system on the performance of the combined cycle power plant within an equatorial environment. The bulk heat utilization and configuration of a dual pressure heat recovery system are investigated. It is observed that the heat system configuration play a vital role in optimizing the combined cycle overall performance, which has proportionality relationship with the operating ambient temperature and relative humidity of the gas turbine. The investigation is carried out within the ambient temperature range of 24℃ to 35℃, relative humidity of 60% to 80%, and a high level steam pressure of 60 bar to 110 bar. The results show that at 24℃ ambient temperature, the heat recovery system has the highest duty of 239.4 MW, the optimum combined cycle power output of 205.52 MW, and overall efficiency of 47.46%. It further indicates that as the ambient temperature increases at an average exhaust gas temperature of 530℃ and mass flow of 470 kg/s, the combined cycle power output and efficiency decrease by 15.5% and 13.7% respectively under the various considerations. This results from a drop in the air and exhaust mass flow as the values of the site parameters increase. The overall results indicate that decreasing the ambient temperature at optimum exhaust gas flow and temperature increases the heat recovery system heat duty performance, the steam generation, overall combined cycle power output and efficiency, which satisfies the research objective.

Economics and Performance Forecast of Gas Turbine Combined Cycle

Forecasts of the various types of gas turbines economics and performance of gas turbine combined cycle （GTCC） with will help power plant designers to select the best type of gas turbine for future Chinese powerplants. The cost and performance of various designs were estimated using the commercial software GT PRO. Improved GTCC output will increase the system efficiency which may induce total investment and will certainly increase the cumulative cash which then will induce the cost and the payback period. The relative annual fuel output increases almost in proportion to the relative GTCC output. China should select the gas turbine that provides the most economical output according to its specific conditions. The analysis shows that a GTCC power plant with a medium-sized 100 to 200 MW output gas turbine is the most suitable for Chinese investors.

燃气-蒸汽联合循环发电机组轴系配置的思考

燃气-蒸汽联合循环发电机组因高效、节能、环保而越来越受到重视, 为此, 从我国当前大力发展燃气-蒸汽联合循环发电机组的实际情况出发, 全面分析联合循环机组轴系的配置型式及其影响, 重点比较了单轴和多轴“2拖1”机组在设备投资、占地面积、建设周期、起动停机、功率和效率、检修和控制系统方面的优缺点, 为燃气-蒸汽联合循环发电新机组建设的轴系配置提供参考。

大型联合钢铁企业低中热值煤气发电综合利用的优化分析

大型联合钢企的副产品低、中热值煤气不是洁净高能燃料,由此建成的煤气蒸汽联合循环机组要比天然气机组效率低8%-10%,排放特性与BTG型机组类似,且有较高投入、较高维护成本、较低可用率及不能适应变负荷运行等,难以满足电网AGC的要求。分析了可燃用低中热值的各种常规容量下的BTG类型与GTCC类型发电机组的经济特性与技术特性,根据东南沿海燃料价格高昂的实际情况,认为对低热值煤气BFG,以350 MW以上大型混烧BTG方式发电是较优的,高炉煤气放散可以接近零、安全可靠、成本较低、排放较少、对各种波动的煤气流量适应性更强,有利于投资方与当地电网。对COREX工艺大型联合钢企,以GTCC为主力是较好的方案。对天然气价格较低、COG/LDG富余较多的地方,结果不同。建议大型联合钢企副产品低、中热值煤气发电,要因地置宜,要根据煤气富余量、燃料价格、用电需求、环境与气候、投资与维护、综合实际供电成本等诸方面综合论证,以得出理性的优化方案。

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。

燃气联合循环发电机组介绍及其凝汽器设计

介绍了燃气联合循环发电机组申凝汽器的结构特点,该凝汽器的后水室侧布置有补偿节,以补偿凝汽器壳体与冷却管纵向热膨胀的差值,后水室下部安装有辅助支撑架。凝汽器壳体上部配置有补水喷淋装置、再循环喷淋装置、高低压减温减压装置等。并对凝汽器接颈设计中扩散角角度、接颈中设置水幕保护等问题进行了探讨。

利用不补燃型燃气—蒸汽联合循环改造燃煤电厂方案的研究

介绍了燃气轮机及其联合循环发电技术(GTCC)的优点。着重分析了应用不补燃余热锅炉型燃气 蒸汽联合循环对现有燃煤电厂进行改造的基本热力学原理,并针对某燃煤电站改造成常规不补燃余热锅炉型燃气 蒸汽联合循环的发电效率和经济性进行理论分析和计算,论证其在技术上和经济上的可行性。