燃气轮机变工况对IGCC系统性能的影响

采用成熟的商业软件Thermoflex对拟在国内建设的200 MW等级IGCC示范机组进行模拟,并对其进行物质和热平衡的核算.降负荷过程中采用目前联合循环燃气轮机较为常用的IGV(压气机进口可转导叶)调节等T3(透平前温)的调节方式,分析了这种调节方式下燃气轮机负荷率对T3、T4(排气温度)、QGe(燃气轮机排气流量)系统的效率、功率、燃料量和蒸汽侧主要参数的影响,得到了IGCC系统变工况特性及各主要参数变化的一般规律,对系统在变工况时的安全性和经济性进行了必要的分析.结果表明:调节方式直接影响系统的变工况性能,在IGCC系统变工况的过程中为了保证系统的经济性和可靠性,尽量使燃气轮机在IGV调节的范围内调控.     

整体煤气化联合循环_IGCC_系统变工况特性

作者分析了影响IGCC系统变工况的因素,基于通用性模块化建模思想,建立了IGCC系统变工况特性模型和开发出相应程序软件,通过大量的计算,得出三种调节方式下系统随负荷与大气温度变化时的变工况特性曲线簇,揭示了系统特性随主要变量变化关系。     

IGCC系统中燃机岛特性研究

IGCC系统由气化岛、燃机岛、常规岛及其辅助系统组成,其中燃机岛对IGCC系统性能有较大的影响。本文利用ThermoFlex软件建立200MW级IGCC系统模型,从系统角度出发,研究IGCC系统中的燃机岛特性,分析燃机岛关键参数变化对IGCC系统的影响。研究结果表明：燃气轮机出力和系统发电量随着大气温度的升高而下降,随着大气压力升高而升高;系统的发电量和系统效率随燃气轮机负荷的下降而下降;燃气轮机出力和系统发电量随压气机进口空气量的减小而减少,随着通流面积的增加而增加。本系统最佳的氮气回注系数为60％及整体空分系数为20％。     

燃气轮机调节方式对IGCC系统变工况性能的影响

为选择合理的燃气轮机调节方式,采用Thermoflex软件建立了200 MW级IGCC系统模型,从系统的角度出发比较研究了燃气轮机的调节方式对燃气顶循环系统、蒸汽底循环系统和整个IGCC系统变工况性能的影响.研究表明:与压气机可转导叶(IGV)不调相比,IGV可调时更有利于提高系统的变工况性能.等燃气透平初温(T3)调...     

基于Matlab的IGCC燃气轮机子系统热力性能的优化分析

分析了IGCC中燃气轮机的特点和变工况规律,建立了IGCC燃气轮机子系统的优化模型,并分别以燃气轮机的出力和系统效率为目标,采用Matlab计算软件进行了优化计算.计算结果揭示了燃气轮机子系统的性能变化规律,表明空分系数和氮气回注系数是影响燃气轮机出力和IGCC系统效率的重要参数,也是优化工作的重点对象.优化结果表明:文中实例所确定的IGCC系统具有良好的热力性能.     

整体煤气化联合循环系统中燃气轮机的变工况特性

采用ThermoFlex软件建立了200 MW级整体煤气化联合循环(IGCC)系统模型,从系统的角度研究了200 MW级IGCC系统中燃气轮机的变工况特性.详细讨论了在3种调节方式下,燃气轮机负荷、整体空分系数(Xas)、氮气回注系数(Xgn)和大气环境条件对系统性能的影响.结果表明:随着燃气轮机负荷的降低,在压气机进口可转导叶(IGV)不调时,燃气透平初温(T3)和燃气透平排气温度(T4)均呈下降趋势;在等T3调节时,T4先升高后降低,转折,最在80%负荷时;而在等T4调节时,T3先缓慢降低,而后快速降低,转折点在70%负荷时.在等T3调节时IGV可关闭的角度比等T4调节时的小.当Xas和Xgn增大时,系统发电效率降低.IGV可调的变工况性能比IGV不调时好.随着大气温度的升高,燃气轮机功率和系统功率均下降.当Xas=0.3时,燃气轮机功率和系统功率均随Xgn的增大而增加.     

船用分轴燃气轮机主要部件变工况性能的初步研究

建立燃气轮机大负荷范围、准确的变工况模型是燃气轮机热力系统建模研究的一个重要方向。其难点之一在于如何获得准确的部件变工况性能曲线。由于各种原因,一般研究人员只能获得少量的燃气轮机运行数据,因此如何利用这些数据获得准确的部件变工况性能曲线就成为需要解决的问题。在这种情况下,作者以某船用分轴燃气轮机为研究对象,利用少量运行数据对燃气轮机部件变工况通用解析解进行修正,并利用拟合的方法得到了大负荷范围内该燃气轮机主要部件较为准确的变工况性能曲线及其表达式。     

带回热微型燃气轮机系统动态过程分析

分析了微型燃气轮机的动态数学模型,利用解析方法,求解了带回热单轴燃气轮机动态方程,对定转速和变转速两种情况下微型燃气轮机负荷变化和甩负荷的动态过程进行了仿真,提出了机组变工况动态性能优化和控制优化的途径。该研究能够为实际机组的运行和系统性能参数的合理匹配提供理论指导。     

微型燃气轮机冷热电联供系统变工况性能研究

设计了以微型燃气轮机为核心的冷热电联供系统并建立了该系统变工况性能分析模型.结合具体算例,对该联供系统在采用"以冷(热)定电"的模式下运行变工况时的热力性能进行了计算分析,揭示了系统在不同调节方式下的变工况性能.结果表明,回热度调节具有较宽的冷热负荷调节范围,因此微型燃气轮机联供系统特别适用于冷热负荷变化大而系统内电负荷较稳定的场合.为使系统变工况时保持较高的性能,当冷热负荷增加时应优先考虑发电功率调节,其次采用回热度调节,最后采取补燃量调节;当冷热负荷减小时宜采用相反的调节顺序.研究结果将对微型燃气轮机冷热电联供系统的设计及运行提供有益的参考和指导.     

压气机静叶可调对燃气轮机和联合循环变工况性能的影响

本文叙述了压气机采用可调静叶对单轴恒速燃气轮机变工况性能的影响。通过计算得到了燃气轮机变工况性能曲线,分析了不同的最大排气温度对静叶调节区的影响,以及在部分负荷下机组效率变化的影响。叙述了压气机静叶调节时对由单轴恒速燃气轮机组成的联合循环的影响,指出这时能改善部分负荷下的效率,因而得到了实际应用。     

Influence of system integration options on the performance of an integrated gasification combined cycle power plant

An IGCC (integrated gasification combined cycle) plant consists of a power block and a gasifier block, and a smooth integration of these two parts is important. This work has analyzed the influences of the major design options on the performance of an IGCC plant. These options include the method of integrating a gas turbine with an air separation unit and the degree of nitrogen supply from the ASU to the gas turbine combustor. Research focus was given to the effect of each option on the gas turbine operating condition along with plant performance. Initially, an analysis adopting an existing gas turbine without any modifications of its components was performed to examine the influence of two design options on the operability of the gas turbine and performance of the entire IGCC plant. It is shown that a high integration degree, where much of the air required at the air separation unit is supplied by the gas turbine compressor, can be a better option considering both the system performance and operation limitation of the gas turbine. The nitrogen supply enhances system performance, but a high supply ratio can only be acceptable in high integration degree designs. Secondly, the modifications of gas turbine components to resume the operating surge margin, such as increasing the maximum compressor pressure ratio by adding a couple of stages and increasing turbine swallowing capacity, were simulated and their effects on system performance were examined. Modification can be a good option when a low integration degree is to be adopted, as it provides a considerable power increase.     

三压再热汽水系统IGCC的设计工况和变工况性能

以三压再热式汽水系统ＩＧＣＣ（整体煤气化燃气－蒸汽联合循环）为研究对象组成了整体空分ＩＧＣＣ系统方案,建立了气化炉,净化系统,燃气轮机,空分装置,余热锅炉,汽轮机各组成部件的数学模型,对ＩＧＣＣ系统的设计工况和变工况特性进行计算,分析了煤气轮机采用不同调节规律和汽轮机采用不同运行方式时对系统变工况性能的影响并提出了合理的运行方式。     

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.     

Operation window and part-load performance study of a syngas fired gas turbine

Integrated coal gasification combined cycle (IGCC) provides a great opportunity for clean utilization of coal while maintaining the advantage of high energy efficiency brought by gas turbines. A challenging problem arising from the integration of an existing gas turbine to an IGCC system is the performance change of the gas turbine due to the shift of fuel from natural gas to synthesis gas, or syngas, mainly consisting of carbon monoxide and hydrogen. Besides the change of base-load performance, which has been extensively studied, the change of part-load performance is also of great significance for the operation of a gas turbine and an IGCC plant.In this paper, a detailed mathematical model of a syngas fired gas turbine is developed to study its part-load performance. A baseline is firstly established using the part-load performance of a natural gas fired gas turbine, then the part-load performance of the gas turbine running with different compositions of syngas is investigated and compared with the baseline. Particularly, the impacts of the variable inlet guide vane, the degree of fuel dilution, and the degree of air bleed are investigated. Results indicate that insufficient cooling of turbine blades and a reduced compressor surge margin are the major factors that constrain the part-load performance of a syngas fired gas turbine. Results also show that air bleed from the compressor can greatly improve the working condition of a syngas fired gas turbine, especially for those fired with low lower heating value syngas. The regulating strategy of a syngas fired gas turbine should also be adjusted in accordance to the changes of part-load performance, and a reduced scope of constant TAT (turbine exhaust temperature) control mode is required.     

Performance evaluation of integrated gasification solid oxide fuel cell/gas turbine systems including carbon dioxide capture

In this study, system layouts for integrated gasification solid oxide fuel cell/gas turbine (IG-SOFC/GT) systems were proposed and their performance was comparatively evaluated. A baseline IGCC was simulated, and the calculation models were validated. Based on the IGCC system, two IG-SOFC/GT system layouts with different SOFC thermal management methods were established, and their performance was analyzed. The IG-SOFC/GT systems were found to produce much higher power and better efficiency than the IGCC. With regard to SOFC thermal management, the exit gas recirculation scheme showed better performance than the cathode heat exchange scheme. The impact of CO₂ capture was investigated in both the IGCC and IG-SOFC/GT systems, and the penalties in power output and efficiency due to pre-combustion CO₂ capture were found to be milder in the IG-SOFC/GT systems than in the IGCC. An IG-SOFC/GT system adopting oxy-combustion-based CO₂ capture was proposed, and its thermal efficiency was predicted to be sensibly higher than the system with pre-combustion CO₂ capture. Its net power output was predicted to be less than that of the system with pre-combustion technology, but was still much larger than that of the IGCC with pre-combustion CO₂ capture.     

Coal to electricity: Integrated gasification combined cycle

An advanced energy conversion system—the integrated gasification combined cycle (IGCC)—has been identified as an efficient and economical means of converting coal to electricity for utility application. Several demonstration projects on a near-commercial scale are approaching the construction stage. A coal conversion facility has been constructed to simulate the operational features of an IGCC. This process evaluation facility (PEF-scale) performs a dual function: (1) acquiring and processing data on the performance of the individual components—coal gasifier, gas clean up, and turbine simulator—that comprise the IGCC concept and (2) simulating the total system in an operational control mode that permits evaluation of system response to imposed load variations characteristic of utility operation. The results to date indicate that an efficient, economical IGCC can be designed so that the gasification/gas clean up plant and the power generation system operate compatibly to meet utility requirements in an environmentally acceptable manner.