大涡模拟在船用燃气轮机进气流场中的应用

燃气轮机进气系统的结构和气动性能是燃气轮机装舰技术研究的一个重要组成部分。针对这方面的要求,进行燃气轮机进气系统的设计及数值模拟计算,为设计制造高性能的船用燃气轮机进气系统提供可靠的依据。对两种方案的进气系统作了数值计算和实验研究,其结果是相当令人满意的,对进气系统的实际使用具有非常重要的意义。     

大涡模拟在防浪级性能研究中的应用

为满足现代舰船对进气过滤系统越来越高的要求,针对进气滤清器的防浪级进行了大涡模拟（Large Eddy Simulation）。亚格子项采用Smagorinsky—Lilly亚格子模型,压力一速度耦合采用SIMPLE算法,空间离散采用中心差分格式,时间离散采用二阶精度的隐式差分格式,获得了反映流场特性的参数分布。与κ—ε湍流模型获得的结果相比较,大涡模拟得到的结果能更详细地反应流场特性。小型风洞上进行的性能实测结果表明数值模拟具有较高的精度,在燃气轮机进气系统的研究中是一种方便快捷的优化设计手段。     

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。     

燃气轮机陆基试验台进气系统阻力模拟装置气动性能数值分析

为某型燃气轮机陆基试验台进气系统设计了一种由5个节流板组成的进气阻力模拟装置,用于模拟燃气轮机实船状态下的进气阻力。采用CFD数值模拟方法,分析该装置阻力模拟装置节流板不同偏转角度对燃气轮机进口空气流场及总压损失的影响,通过试验验证了数值模拟结果的准确性。数值结果表明：节流板顺时针持续偏转,下流底部回流区域逐渐扩大,下游主流流速分布较均匀,有利于燃气轮机运行;同时节流板偏转使得燃气轮机进口截面顶部区域低速区扩大,截面高速分布区域更加均匀。节流板逆时针偏转会增大燃气轮机进口截面不均匀度,且引起的总压损失要大于顺时针偏转,不利于燃气轮机运行。同时还通过试验验证了数值计算模型和相关分析的可靠性,为节流板的设计、安装提供了重要的理论依据。     

燃气轮机进气系统结霜分析及对策

燃气轮机进气系统发生结霜对燃气轮机安全运行危害很大。本文分析了燃气轮机进气系统发生结霜现象的产生机理,并提出解决问题的办法,这对燃气轮机用户和设计成套单位有一定的参数价值。     

某舰用燃气轮机舷侧进气系统性能试验研究

与燃气轮机常规进气方式相比，舰用燃气轮机舷侧进气系统对风速、风向等环境条件更为敏感，从而影 响整体性能表现。为验证某舰用燃气轮机舷侧进气系统在不同进气方向下总体性能是否满足设计要求，本文搭 建了该进气系统比例模型，并在其中布置了滤清器、稳压室、消声器等损失部件模型，对舷侧进气系统在5个常 见的进气方向下的整体性能表现进行了试验研究，对M进气方向下7个关键截面上流场进行了详细测量。试 验结果发现，进气方向明显影响舷侧进气系统性能，进气方向垂直于百页窗时进气系统总阻力损失最小。进气 系统中前端部件，如百叶窗、滤清器、稳压室等部件流动损失受进气系统的影响较为明显，消声器等进气系统尾 端部件的流动损失基本不受影响。速度场测量结果表明，进气方向同样会影响进气系统出口截面上流动畸变情 况，变化趋势与进气系统总阻力损失变化趋势基本相反。试验结果表明，在不同进气方向下，舷侧进气系统设计 方案的总阻力损失、出口截面畸变、主机功率损失均满足设计要求。     

燃气轮机惯性级分离装置的气动特性研究

气动特性是燃气轮机惯性级分离装置工作性能的宏观指标,进气通道的气动性能越差,压气机效率、压比及燃气轮机的功率越低。对燃气轮机一种惯性级导叶进行气动损失特性研究,分别对进口流速工况为2.0、2.5、3.0、3.5、4.0m/s的流道进行研究。首先从数值模拟的角度对二维流道流场模拟,得出数值模拟气动损失数据。然后从试验研究的角度对该惯性级导叶气动损失特性测试。分析数值模拟与试验研究的结果,得出:不同进口流速下,两者总压损失都近似成线性关系;气动阻力损失系数都基本保持不变,但两者存在一定的偏差;数值建模参数假设的误差是导致偏差的主要原因。     

进气冷却在微型燃气轮机冷、电联供系统中的应用

对进气冷却在微型燃气轮机冷、电联供系统中的应用进行了研究.提出了用联供系统生产的冷能对压气机进口空气进行冷却来改善联供系统在高温天气下性能的方法,并结合具体算例进行了分析.结果表明：进气冷却可使微型燃气轮机在环境温度升高的情况下仍能稳定在设计工况点附近运行;环境温度越高,其对微型燃气轮机性能改善的效果越明显;余热供冷功率会因冷却空气而减少,但用微型燃气轮机比进气冷却前多发的电功率来驱动电空调制冷,可补偿制冷功率损失,并使系统总的供冷功率得到很大提高;进气冷却是高温天气下提高微型燃气轮机冷、电联供系统性能的有效措施.     

舰船燃气轮机进口流场畸变的实验研究与分析

本文对舰船燃气轮机进口流场进行了详细测量，分别研究了燃气轮机轴线离进气室底部距离、燃气轮机进口网及进气室中台阶尺寸及形式对进口畸变度的影响，并与 Ｇ Ｅ公司给出的进口容限指标进行了比较。结果表明，本文设计的结构尺寸完全满足畸变指标的要求，通过实验，明确了舰船燃气轮机进口网的主要作用是拦截异物，而并非增加气流均匀度。     

燃气轮机天然气校正沃伯指数公式优化

当环境温度变化或燃气轮机进气加热时,燃气轮机逻辑中沃伯指数公式计算值保持不变,不能实时 反映燃气轮机的燃烧工况。通过分析燃气轮机DLN2.0 +燃烧系统的天然气校正沃伯指数公式,提出压气机 进气温度对校正沃伯指数更合理的修改公式。此新公式能全面正确反映环境温度变化或进气加热时的沃伯 指数变化,对现场实际运行和燃气轮机系统优化设计也有帮助。     

燃气轮机进气雾化式蒸发冷却控制技术研究

大气环境温度对燃气轮机性能的影响很大,加装燃气轮机进气雾化冷却系统对改善燃气轮机性能具有很高的实用价值.通过对燃气轮机进气雾化冷却工作原理的分析,提出了一种基于PLC的燃气轮机进气雾化冷却控制系统的设计方案以及功能实现.运行结果表明,该控制系统自动化程度高,工作稳定性好,性能可靠.配置控制系统的燃气轮机进气雾化式冷却撬体投运后,PG6551(B)型燃气轮机功率相对增加8.35%,效率相对提高3.24%.     

进气冷却对燃机联合循环的性能影响分析

  [目的]  为了提高联合循环电厂运行灵活性,保证较好的机组运行经济性,避免燃气轮机在低效运行区,对燃机的进气冷却系统进行分析研究。  [方法]  基于GT-Pro/GT-Master软件,通过对采用进气冷却系统前后的燃机联合循环机组进行热平衡模拟计算,对机组的性能变化以及影响因素进行研究、对机组效率进行敏感性分析。  [结果]  分析结果表明:进气冷却系统可以大幅提高燃机的出力和效率;采用进气冷却系统后联合循环机组的出力增加,但效率略有下降。  [结论]  因此,对于联合循环机组,若电网允许机组多发电,则可以考虑设置进气冷却系统;若机组全年总出力固定,且年利用小时数并不饱满,则不宜设置进气冷却系统。     

A new approach for enhancing performance of a gas turbine (case study: Khangiran refinery)

There are various methods which are commercially available for turbine air inlet cooling aiming to improve gas turbine efficiency. In this study a new approach has been proposed to improve performance of a gas turbine. The approach has been applied to one of the Khangiran refinery gas turbines. The idea is to cool inlet air of the gas turbine by potential cooling capacity of the refinery natural-gas pressure drop station. The study is part of a comprehensive program aimed to enhance gas turbines performance of the Khangiran gas refinery. The results show that the gas turbine inlet air temperature could be reduced in range of 4–25 K and the performance could be improved in range of 1.5–5% for almost 10 months.     

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...     

Performance analysis on various system layouts for the combination of an ambient pressure molten carbonate fuel cell and a gas turbine

This study analyses hybrid systems combining a molten carbonate fuel cell (MCFC) operating at ambient pressure and a gas turbine. Various possible system layouts, with the major difference among these layouts being the heating method of the turbine inlet gas, are proposed and their design performances are simulated and comparatively analyzed. Power of the MCFC in the hybrid system is explained in terms of the cathode inlet air temperature. Power of the gas turbine differs among various layouts because of large difference in the turbine inlet temperature. The direct firing in front of the turbine allows far higher turbine inlet temperature, and thus greater gas turbine power than the indirect heating of the inlet gas. The optimum pressure ratio of the directly fired system is higher than that of the indirectly fired system. The directly fired system allows not only much larger system power and higher optimum efficiency but also greater flexibility in the selection of the design pressure ratio of the gas turbine. In addition, the directly fired system can better accommodate the specifications of both current micro gas turbines and advanced gas turbines than the indirectly fired system.     

应用溴化锂吸收式制冷技术提高燃气轮机电站发电效率的研究

对燃气轮机进口的空气进行预冷,能够提高发电机组的输出功率。与蓄冷方法相比,使用燃气轮机－蒸汽联合循环电站余热锅炉低压蒸发器的一部分蒸汽为热源,利用溴化锂吸收式制冷机制取冷源,冷却燃气轮机进口处的空气,以提高发电机组的输出功率,该方法技术可行,经济效益显著。     

Energy and exergy analyses of a CFB‐based indirectly fired combined cycle power generation system

Combined cycle configuration has the ability to use the waste heat from the gas turbine exhaust gas using the heat recovery steam generator for the bottoming steam cycle. In the current study, a natural gas‐fired combined cycle with indirectly fired heating for additional work output is investigated for configurations with and without reheat combustor (RHC) in the gas turbine. The mass flow rate of coal for the indirect‐firing mode in circulating fluidized bed (CFB) combustor is estimated based on fixed natural gas input for the gas turbine combustion chamber (GTCC). The effects of pressure ratio, gas turbine inlet temperature, inlet temperatures to the air compressor and to the GTCC on the overall cycle performance of the combined cycle configuration are analysed. The combined cycle efficiency increases with pressure ratio up to the optimum value. Both efficiency and net work output for the combined cycle increase with gas turbine inlet temperature. The efficiency decreases with increase in the air compressor inlet temperature. The indirect firing of coal shows reduced use with increase in the turbine inlet temperature due to increase in the use of natural gas. There is little variation in the efficiency with increase in GTCC inlet temperature resulting in increased use of coal. The combined cycle having the two‐stage gas turbine with RHC has significantly higher efficiency and net work output compared with the cycle without RHC. The exergetic efficiency also increases with increase in the gas turbine inlet temperature. The exergy destruction is highest for the CFB combustor followed by the GTCC. The analyses show that the indirectly fired mode of the combined cycle offers better performance and opportunities for additional net work output by using solid fuels (coal in this case). Copyright © 2009 John Wiley & Sons, Ltd.     

Maisotsenko循环在燃气轮机进气冷却中的应用研究

采用基于Maisotsenko循环的露点间接蒸发式冷却作为进气冷却的手段,研究了不同环境条件下其对燃气轮机性能的提升效果。建立了针对某9E级燃气轮机的热力循环过程的计算模型,并利用该热力模型分析了进气温度变化对燃机出力的影响。基于Maisotsenko循环的原理,以温降为指标对露点间接蒸发冷却器的性能进行了分析。以功率和效率作为指标,对燃气轮机性能随环境条件的变化情况做了数值模拟,对露点蒸发式冷却与无进气冷却、直接喷雾式冷却对燃机性能的影响进行了计算分析。结果表明,在高温低湿度的条件下,露点间接蒸发式冷却能有效提升燃机性能。     

Comparison of evaporative inlet air cooling systems to enhance the gas turbine generated power

The gas turbine performance is highly sensitive to the compressor inlet temperature. The output of gas turbine falls to a value that is less than the rated output under high temperature conditions. In fact increase in inlet air temperature by 1°C will decrease the output power by 0.7% approximately. The solution of this problem is very important because the peak demand season also happens in the summer. One of the convenient methods of inlet air cooling is evaporating cooling which is appropriate for warm and dry weather. As most of the gas turbines in Iran are installed in such ambient conditions regions, therefore this method can be used to enhance the performance of the gas turbines. In this paper, an overview of technical and economic comparison of media system and fog system is given. The performance test results show that the mean output power of Frame‐9 gas turbines is increased by 11 MW (14.5%) by the application of media cooling system in Fars power plant and 8.1 MW (8.9%) and 9.5 MW (11%) by the application of fog cooling system in Ghom and Shahid Rajaie power plants, respectively. The total enhanced power generation in the summer of 2004 was 2970, 1701 and 1340 MWh for the Fars, Ghom and Shahid Rajaie power plants, respectively. The economical studies show that the payback periods are estimated to be around 2 and 3 years for fog and media systems, respectively. This study has shown that both methods are suitable for the dry and hot areas for gas turbine power augmentation. Copyright © 2007 John Wiley & Sons, Ltd.