考虑透平冷却的再热燃气轮机联合循环热力性能参数影响

燃气轮机再热被认为可以提高效率和比功。本文基于准一维透平连续膨胀冷却模型和底循环简明估算模型对再热燃气轮机联合循环进行热力性能研究,以GT-26燃气轮机为基准分析了循环总压比、燃烧室出口温度、再热压力等关键参数对联合循环热力性能的影响特性,并与无再热燃气轮机的联合循环性能进行了比较。研究表明：不同燃烧室出口温度下的再热燃气轮机联合循环效率最大值对应的循环总压比相差不大;不同燃烧室出口温度和循环总压比下,联合循环效率对应的最佳高压透平膨胀比不同。当燃烧室出口温度为1 683 K时,在各自的效率最佳压比下,再热燃气轮机联合循环比无再热燃气轮机的联合循环效率提高了1.34个百分点,同时比功提高了33.2%。     

注水对燃气轮机联合循环机组性能试验研究

为了对比研究某机组注水脱硝系统对燃机出力及热耗率等的影响,对某燃气轮机联合循环机组进行性能试验。试验共分3个试验工况:相同基础负荷注水前后性能试验及注水后机组最大出力工况,计算了不同工况下机组出力及热耗率,计算了注水脱硝系统投运后NOx减排量和增加的度电成本,最后分析了注水对机组运行的影响,试验结果表明注水能够提高燃气轮机出力,增加热耗,降低热效率,注水可以大幅降低燃气轮机NOx排放量。注水会增加度电成本,降低电厂经济性。     

基于IGV控制的先进燃气轮机联合循环运行优化

为了达到高效的先进燃气轮机联合循环优化运行,提高循环的能源利用率,以先进燃气轮机联合循环技术为研究对象,通过以有机物为工质的朗肯循环回收燃气轮机的余热,进行燃气轮机联合循环变工况仿真模拟来研究联合循环运行特性,分析了环境温度和压气机进口导叶(IGV)调节对联合循环运行特性的影响,制定了IGV角度的优化控制策略。结果表明:在变负荷工况和不同环境温度下,调节燃气轮机的空燃比,可以优化该燃气轮机联合循环的运行特性,提升联合循环效率。     

某燃机的模块化仿真及其特性分析

基于Matlab/simulink仿真平台,采用模块化建模思想,建立了R0110燃气轮机的动态仿真模型,模型描述了压气机、燃烧室、燃气透平等主要部件的特性。利用模型进行了载荷扰动和增投燃料对燃气轮机运行影响的仿真,结果表明所建立的仿真模型正确反映了燃气轮机的运行特性,可以进一步用于燃气蒸汽联合循环。     

压气机进气温度对联合循环机组性能影响的探讨

通过热力学模型分析和热力系统平衡计算,研究了9F级燃气轮机压气机进气温度变化对燃气轮机及联合循环发电机输出功率及效率的影响,压气机进气温度变化不仅对燃气轮机联合循环机组满负荷时的性能有影响,在部分负荷运行时对机组的效率也有影响。通过对压气机进气温度进行调节,可以改善燃气轮机联合循环的运行性能。     

燃气-蒸汽联合循环变工况调节方案对比分析

针对现存PG9351FA燃气轮机对应的燃气-蒸汽联合循环,分析了3类调节方案下燃气轮机循环、蒸汽轮机循环和联合循环的变工况特性.结果表明:针对基准机组,采用IGV调节方案不利于燃气轮机循环高效运行,但有利于联合循环运行;调节方案对蒸汽轮机循环的影响大于燃气轮机循环,故联合循环效率最高的调节方案为尽量维持T4在透平出口极限温度运行,该方案对应联合循环效率在低负荷下比IGV T3-F方案对应联合循环效率提升2%以上;为了变工况运行最佳,应尽可能采用IGV调节方案并且在较高蒸汽轮机循环效率下运行.     

某发电厂燃气轮机燃烧脉动超限的原因分析

针对某电厂三菱M701F4型燃气轮机联合循环机组运行过程中因发电机电流互感器二次侧开路,导致功率测量模块输出数据异常,引起燃烧室压力脉动超限跳机,阐述了M701F4型燃气轮机透平保护、控制系统及ACPFM的功能以及电测故障对控制系统的影响,通过分析燃气轮机燃烧脉动跳闸的原因并在原因剖析的基础上,提出了提高发电机三相电功率测量系统可靠性等建议,可为同类型机组提供一定的参考。     

生物质整体气化联合循环中燃烧室的分析

基于联合循环和能量梯级利用的概念,用分析和燃气变比热热力计算法研究生物质整体气化联合循环(BIGCC)中燃烧室的能量利用与损失情况。计算结果表明:燃用生物质燃料气,随燃气轮机初温提高,燃气轮机热效率提高,燃烧室的效率提高,但随燃烧室出口燃气温度的升高,燃烧室的效率提高幅度变缓;燃烧室的效率不仅与燃烧室燃气出口温度、空气入口温度和压力密切有关,还与燃料的组分的相对含量和发热量有关;对生物质燃料气、两种不同热值煤气在燃烧室出口燃气温度为1147℃时的燃烧室的效率进行了比较,两种不同热值煤气的效率较低,生物质燃料气效率最大。图2表2参11     

9E级燃气轮机部分负荷进气加热提效技术研究与工程应用

本文在介绍燃气轮机设备运行特性和我国当前燃气轮机发电行业现状的基础上,对燃气轮机部分负荷运行情况进行了仿真计算研究和运行数据分析研究。根据实际运行数据分析,我国燃气电厂机组普遍存在实际运行负荷长期低于设计负荷、燃气轮机部分负荷运行效率衰减、高品位能源浪费巨大的问题。针对燃气电厂机组运行现状,本文通过对PG9171E型燃气轮机机组采用实际运行数据分析和仿真建模计算的方法,重点研究了燃气轮机入口空气温度调整对联合循环机组部分负荷工况性能的影响。根据研究结果,提出了一种利用燃气联合循环系统低品位余热作为热源的燃气轮机联合循环进气加热部分负荷提效技术,并对该技术在我国不同型号燃气轮机机组上的技术应用进行了分析。研究结论和实践结果表明,本文所述的燃气轮机部分负荷进气加热技术系统简洁,系统改造附加进气压损较小,能够适用于我国大部分在运燃气联合循环机组,并且能够显著提高联合循环部分负荷工况的运行效率。     

预混燃烧下环境温度对某型燃气轮机燃烧稳定性和NOx排放影响的 数值研究

环境温度通过改变燃烧室入口空气温度进而影响燃气轮机燃烧稳定性和NO_x排放。为了掌握预混燃烧模式下环境温度对燃气轮机燃烧稳定性和NO_x排放的影响规律,本文以某重型燃气轮机燃烧室为研究对象,采用SAS湍流模型和涡耗散概念燃烧模型,通过改变环境温度,对多旋流喷嘴燃烧室预混燃烧模式下燃烧稳定性和NO_x排放进行了数值计算。研究结果表明:在燃气轮机预混燃烧模式下,提升燃气轮机环境温度,有利于提高燃烧室燃烧稳定性;环境温度从0℃上升到30℃,在不调整燃料和空气流量的情况下,燃烧室出口NO_x排放质量分数增加97.8%。     

Evaluation of water injection effect on compressor and engine performance and operability

Gas turbine performance enhancement technologies such as inlet fogging, combustor water/steam injection and overspray are being employed by users in recent years without fully evaluating their effect on gas turbine performance and operability. The water injection techniques can significantly affect the engine operating point thus a careful analysis should precede the application of performance enhancement devices, especially when the devices are retrofitted to old engines or engines operating at extreme conditions. The present paper examines the most widespread techniques that implement water injection by using in-house models that can reproduce the effects of water injection on the gas turbine and compressor off-design operation. The results are analyzed with respect to both performance augmentation and engine operability in order to give further insight on gas turbine operation with water injection. The behaviour of the gas turbine is interpreted while the risks on engine integrity due to water injection are identified.     

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.     

Water and steam injection in micro gas turbine supplied by hydrogen enriched fuels: Numerical investigation and performance analysis

This paper investigates the energetic and environmental performance of micro gas turbine plant with two proposed concurrent improvements: the methane-based fuel enriched by hydrogen and the humidification of the plant cycle. The energetic and environmental benefits of both features are well-know, and the aim of this work is the analysis of their combined impact on the micro gas turbine operation. Despite enhancing fuel with H₂ involves significant advantages like greenhouse emission reduction and a better combustion in case of low LHV fuels, most of commercial micro gas turbine combustors are not able to burn fuels with high hydrogen content unless structurally modified. On the contrary, has been demonstrated that humidified gas turbines (i.e., gas turbines with water injection, humid air turbine (HAT) and steam injection gas turbine (STIG) cycles) improve the combustion stability as well as electric power delivered and plant efficiency. Hence, in order to investigate the feasibility of the concurrent two features, the first step of this work was the thermodynamic analysis of a micro gas turbine supplied by methane-based fuels enriched with H₂ up to 20%_vol, considering both dry and humidified cycles. Since a combustion anomaly was detected, i.e., flashback, in the CFD study on the combustion chamber, a steam injection in the combustor has been added in the plant layout with the aim of overcoming the anomaly, and its effect on the combustion process has been analyzed also raising the hydrogen content up to 30%_vol. The main outcome of this paper is the assessment of the feasibility of supplying the combustor of the proposed HGT-STIG micro gas turbine with a hydrogen enrichment up to 30%_vol, achieving a safe and regular combustion mainly owing to a steam injection mass flow equal up to 125% of fuel flow.     

High performance SOFC/GT combined power generation system with CO2 recovery by oxygen combustion method

The authors newly propose and investigate two types of carbon dioxide recovering SOFC/GT combined power generation systems in which a gas turbine with carbon dioxide recycle or water vapor injection is adopted as the bottoming cycle. In these systems, fuel gas is first introduced to a SOFC, and its exhaust fuel gas is afterburned by pure oxygen. Carbon dioxide or water vapor is also injected into the combustor to reduce the combustion gas temperature. The obtained combustion gas, which is composed of only carbon dioxide and water vapor, is introduced to a gas turbine in the bottoming cycle. The exhaust gas of the gas turbine preheats the injection gas, and then, carbon dioxide is separated by only cooling and water condensation. It is made clear that the overall efficiency of the system with carbon dioxide recycle reaches 63.87% (HHV) or 70.88% (LHV), and that of the system with water vapor injection reaches 65.00% (HHV) or 72.13% (LHV). These values are sufficiently high, indicating that the proposed systems are worth further research and development.     

Thermodynamic modeling of a gas turbine cycle combined with a solid oxide fuel cell

This study examines the performance of a high-temperature solid oxide fuel cell combined with a conventional recuperative gas turbine (GT–SOFC) plant, as well as the irreversibility within the system. Individual models are developed for each component, through applications of the first and second laws of thermodynamics. The overall system performance is then analyzed by employing individual models and further applying thermodynamic laws for the entire cycle, to evaluate the thermal efficiency and entropy production of the plant. The results of an assessment of the cycle for certain operating conditions are compared against those available in the literature. The comparisons provide useful verification of the thermodynamic simulations in the present work. The comparisons provide useful verification of the thermal simulations in the present work. Further outcomes indicate that increasing the turbine inlet temperature results in decreasing the thermal efficiency of the cycle, whereas it improves the net specific power output. Moreover, an increase in either the turbine inlet temperature or compression ratio leads to a higher rate of entropy generation within the plant. It was found that the combustor and SOFC contribute predominantly to the total irreversibility of the system. About 60% of the irreversibility takes place in the following components at typical operating conditions: 31.4% in the combustor and 27.9% in the SOFC. A comparison between the GT–SOFC plant and a traditional GT cycle, based on identical operating conditions, is also made. Although the irreversibility of a modern plant is higher than that of a conventional cycle, the superior performance of a GT–SOFC, in terms of thermal efficiency and environmental impact (lower CO₂ emissions), over a traditional GT cycle is evident. It has about 27.8% higher efficiency than a traditional GT plant. In this case, the thermal efficiency of the integrated cycle becomes as high as 60.6% at the optimum compression ratio.     

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.     

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.     

A modern injected steam gas turbine cogeneration system based on exergy concept

Factors such as low capital cost, good match of power and heat requirements and proven reliability can sometimes lead an end user into purchasing gas turbines for use in a modern cogeneration plant. The steam‐injected gas turbine is an attractive electrical generating technology for mitigating the impacts of rising energy prices. According to such mentioned above this paper is to provide results of an optimization study on cogeneration power cycle, which works by gas turbine with recuperator and injection steam added to the combustor of the gas turbine. The performance characteristics of the cycle based on energy and exergy concepts and based upon practical performance constraints were investigated. The effect of the recuperator on the cycle was greatly clarified. Results also show that the output power of a gas turbine increases when steam is injected. When extra steam has to be generated in order to be able to inject steam and at the same time to provide for a given heat demand, power generating efficiency increases but cogeneration efficiency decreases with the increasing of injected steam. Copyright © 2004 John Wiley & Sons, Ltd.     

An overview on dry low NOx micromix combustor development for hydrogen-rich gas turbine applications

The paper presents a survey of the interactive optimization cycle at Aachen University of Applied Sciences, used for the development of a new low emission Micromix combustor module for application in hydrogen fueled industrial gas turbines. During the development process, experimental and numerical methods are applied to optimize a given baseline combustor with 0.3 mm nozzles with respect to combustion efficiency, combustion stability, higher thermal power output per nozzle and reduced manufacturing complexity.Within the described research cycle combustion and flow simulations are used in the context of parametric studies for generating optimized burner geometries and the phenomenological interpretation of the experimental results. Experimental tests, carried out on an atmospheric combustion chamber test stand provide the basis for validation of simulation results and proof of the predicted combustion characteristics under scaled down gas turbine conditions.In the presented studies, an integration-optimized Micromix combustor with a nozzle diameter of 0.84 mm is tested at atmospheric pressure over a range of gas turbine operating conditions with hydrogen fuel. The combustor module offers an increase in the thermal power output per nozzle by approx. 390% at a significant reduced number of injectors when compared to the baseline design. This greatly benefits manufacturing complexity and the robustness of the combustion process against fuel contamination by particles.During atmospheric testing, the optimized combustor module shows satisfactory operating behavior, combustion efficiency and pollutant emission level. Within the evaluated operating range, which correlates to gas turbine part-, full- and overload conditions, the investigated combustor module exceeds 99% combustion efficiency. The Micromix combustor achieves NO_x emissions less than 2.5 ppm corrected to 15 Vol% O₂ at the design point.Based on numerical analyses and experimental low pressure testing, a full-scale gas turbine combustion chamber is derived. High pressure testing in the auxiliary power unit Honeywell/Garrett GTCP 36–300 shows stable operation during acceleration of the engine, during IDLE and during load variations between IDLE and Main Engine Start (MES) mode. Throughout the investigated operating range, the combustion chamber generates low NO_x emissions under full-scale gas turbine conditions.     

Performance of a mixed gas–steam cycle power plant obtained upgrading an aero-derivative gas turbine

The performance that can be achieved in a power plant obtained upgrading a typical aero-derivative gas turbine is analysed. The methodology is based on the off-design analysis of the gas generator (compressor and high pressure turbine) in the upgraded plant configuration and is applied to the design of a power plant based on the recuperative water injected cycle. The gas generator operating region and its boundary have been evaluated for the upgraded plant configuration; an optimization procedure has been established in order to show the maximum efficiency and power output that can be achieved.