Effects of stator bending on pressure field and loss of transonic turbine stage

To study effects of the upstream flow field changing on the downstream flow field of transonic turbine, different three-dimensional bowed blades, which are the stator blades of transonic turbine stage, were designed in this paper. And then numerical calculations were carried out. The effects on downstream flow field were studied and analyzed in detail. Results show that, at the middle of stator blades, although the increasing Maeh number causes the increase of shock-wave strength and friction, the middle flow field of downstream rotors is improved obviously. It is an important change in transonic condition. This causes the loss of the rotor＇ s middle part decreased greatly. Correspondingly, efficiency of the whole transonic stage can be increased.

Development and Installation of High Pressure Boilers for Co-Generation Plant in Sugar Industries

The sugar cane containing minimum 30% fiber was referred as bagasse and used the generation of power required for the operation of sugar mill. The bagasse is fired in the boiler for producing steam at high pressure, which is extracted through various single high capacity turbines and used in the process. The installation of high pressure boilers and high pressure turbo-generators has provision for the operation of co-generation plant during the off-season also that enhances the power generation from 9MW to 23MW. The annual monetary benefits achieved are Rs. 204.13 million and this was based on cost of power sold to the grid @ Rs 2.548 per unit, sugar season of 219 days and off season of 52 days. This required an investment of Rs 820.6 million. The investment had an attractive simple payback period of 48 months.

Inhomogeneous Hardness Distribution of High Pressure Torsion Processed IF Steel Disks

The inhomogeneous hardness distribution of high pressure torsion (HPT) processed IF steel disks along different directions is investigated. The results indicated that there exists inhomogeneous distribution in HPT processed IF steel disks, giving lower hardness in the center and higher hardness in the edge regions. However, on the axisymmetrical section testing plane of the disks’ thickness direction, there is a soft zone near the surface of disks. Further results from radius testing plane of different depths from the surface of HPT processed disks show that the inhomogeneity rules of hardness distribution on the radius direction are similar to that on the thickness direction. Compared with the initial state, different stages of HPT (compression and compression + torsion) can both remarkably increase the hardness of IF steel disks. Microstructure investigation results can give a well support to verify the rules of hardness distribution, showing hardly no change of grains in center and sever plastic deformation in edge. The inhomogeneous distribution of stress and strain with the huge friction between anvil and disks in the process of HPT play an important role of hardness and microstructure distribution.

车用柴油机高压比宽流量增压器研制

目的 对于单级高压比宽流量增压器,为适应发动机强化指标,进行一系列的改进设计。方法 利用仿真设计与试验相结合的方法,对高海拔环境应用增压器进行改进设计。通过理论推导,确定压气机及涡轮的气动性能优化设计方法,开展高稳定裕度转子轴承系统设计方法研究与验证。结果 匹配高压比宽流量增压器的发动机与原机相比,高原功率恢复了17%,发动机排气温度降低了7%,增压器转速降低了13%。结论 在原机的基础上设计了压比为4.6的宽流量高性能涡轮增压器,成功实现了高压比宽流量增压器的设计,满足了发动机平原、高原不同环境的运行需求。

某300MW机组高压进汽结构气动优化

采用数值模拟的方法对某300MW汽轮机的高压进汽结构进行了气动优化,通过增大关键部位通流面积、增大过渡倒圆,降低了流速,总压损失由4.11%降低到0.045%,出口静压不均匀度由0.67降低到0.020。

Influence of exit-to-throat width ratio on performance of high pressure convergent-divergent rotor in a vaneless counter-rotating turbine

This paper describes the redesign of a high pressure rotor (with exit Mach number around 1.5) for the vaneless counter-rotating turbine by choosing adequate exit-to-throat width ratio. Based on the previous design analysis and test results, effects of the exit-to-throat width ratio on the performance of the transonic turbine cascade were proposed. In order to investigate the influence of the exit-to-throat width ratio on the performance of the turbine cascade, a flow model of the convergent-divergent turbine cascade was constructed by using the theory of Laval nozzle. Then a method on how to choose the adequate exit-to-throat width ratio for the turbine cascade was proposed. To validate the method, it was used to calculate the adequate exit-to-throat width ratio for the high pressure rotor of the vaneless counter-rotating turbine. The high pressure turbine rotor was redesigned with the new exit-to-throat width ratio. Numerical simulation results show that the isentropic efficiency of the redesigned vaneless counter-rotating turbine under the design condition has increased by 0.9% and the efficiencies under the off-design conditions are also improved significantly. On the original design, a group of compressional waves are created from the suction surface after about 60% axial chord in the high pressure turbine rotor. While on the new design the compressional waves are eliminated. Furthermore, on the original design, the inner-extending waves first impinge on the next high pressure turbine rotor suction surface. Its reflection is strong enough and cannot be neglected. However on the new design the inner-extending waves are weakened or even eliminated. Another main progress is that the redesigned high pressure turbine rotor is of practical significance. In the original rotor, a part of the blade (from 60% axial chord to the trailing edge) is thin leading to the intensity problem and difficult arrangement of the cooling system. In the new design, however, the thickness distribution of the rotor airfoil along the chord is relatively reasonable. The intensity of the rotor is enhanced. It is possible to arrange the cooling system reasonably.

Numerical approach to the modelling of transient interaction of prospective combustor concepts and conventional high pressure turbines

The Institute of Gas Turbines and Aerospace Propulsion at Technische Universitait Damstaxlt conducts research projects in the field of“combustor turbine interaction”(CTI).This paper presents numerical studies on the interaction between novel combustion concepts and conventional“high pressure turbine”(HPT)stages.In order to obtain higher efficiency and reduce emissions of jet engines,it is necessary to apply innovative and revolutionary technologies.The most promising technical solutions are based on the cycle processes,employing“pressure gain combustion”(PGC)methods PGC methods provide a significant thermal efficiency enhancement and low NO_(x)-emission rates at the same time.The investigations presented in this paper give information on the integrability of revolutionary combustion concepts into conventional engine architecture.This paper aims at providing insight into the numerical modelling of the transient behaviour of prospective combustion outflow and its influence on the operation of HPTs,especially on the first stage.The focus is on the aerodynamic effects and loss mechanisms within the blade passage.The interaction between the two components plays an important role.To study the performance under new conditions,an engine-like HPT geometry is used.This study reveals a decrease in turbine efficiency with transient inflow conditions compared to a steady-state inflow case.The decrease is primarily due to the interation between transient inflow and the loss mechanisms in the turbine.The presented research was done as part of the project“Technologien fir REVolutionire Arbeits Prozesse”(TREVAP)

Aero-thermal redesign of a high pressure turbine nozzle guide vane

The current article presents conceptual,preliminary and detailed aero-thermal redesign of a typical high pressure turbine nozzle guide vane.Design targets are lower coolant consumption,reduced manufacturing costs and improved durability.These goals are sought by 25%reduction in vane count number and lower number of airfoils per segment.Design challenges such as higher airfoil loading,associate aerodynamic losses and higher thermal loads are discussed.In order to maximize coolant flow reduction and avoid higher aerodynamic losses,airfoil Mach distribution is carefully controlled.There has been an effort to limit design changes so that the proven design features of the original vane are used as much as possible.Accordingly,the same cooling concept is used with minor modifications of the internal structures in order to achieve desired coolant flow and internal heat transfer distribution.Platforms of the new design are quite similar to the original one except for cooling holes and application of thermal barrier coating(TBC).Detailed aerodynamics/heat transfer simulations reveals that the reduced trailing edge(T.E.)blockage and skin friction dominated the negative effect of increased secondary losses.As a result the reduced design performs acceptable in terms of total pressure loss and improving stage efficiency for a wide range of varying pressure ratio.Moreover,more than 20%cooling mass flow can be saved;while maximum and average metal temperatures as well as cross sectional temperature gradients have not been changed much.

Comprehensive rotor service life study for high&intermediate pressure cylinders of high power steam turbines

The paper provides a comprehensive scheme for assessment of the residual service life and extension of operating life of steam turbine rotors with expired fleet service life.The residual service life of high temperature rotors for high&intermediate pressure cylinders of K-200-130-3 steam turbine without heat grooves calculated and it was showed that the residual service life of high&intermediate pressure rotors without grooves has been extended as compared to the K-200-130-1 turbine rotors with grooves.Also residual life management by supplying hot steam to the HPC and 1PC seals was investigated and it was noted their significant impact on the residual service life.

采用样条曲面非轴对称端壁成型的高压涡轮动叶气动优化

为了提升高负荷涡轮级的气动效率,发展了基于样条曲面的非轴对称端壁造型方法。以该参数化造型方法为基础,结合高效智能优化算法和经过校核的数值仿真方法,建立了涡轮非轴对称端壁设计优化平台,并以某小展弦比高压涡轮级为研究对象,以效率为优化目标,以流量为约束条件,在级环境和发动机工况下开展了非轴对称端壁优化设计。结果表明:优化设计后的涡轮动叶相对于参考设计,涡轮级的总总效率提升0.26%;非轴对称端壁造型改变了动叶下端壁附近的压力分布,动叶吸力面侧压力系数相对于参考设计显著提升,这降低了动叶叶片通道内的横向压力梯度,抑制了通道中的二次流动;非轴对称端壁造型改变了叶片通道中的涡系结构,相对于参考设计,非轴对称端壁造型使得马蹄涡压力面分支在叶片通道内部沿着叶片压力面迁移,在靠近通道出口的位置才汇入通道涡,这削弱了通道涡的强度,进而降低了气动损失,提高了涡轮级效率。

俄制1000MW核电汽轮机高压缸变形特征的数值分析和实测研究

汽缸是汽轮机的重要部件,且具有很高的加工和安装精度,长期运行后常常出现不可恢复的变形,对其安全经济运行带来负面影响。利用有限元方法分析了某俄制核电汽轮机高压缸在各种因素作用下的变形情况,利用激光三维扫描技术对该汽缸静态下的结构和变形进行了测量,并将二者进行了对比研究。结果表明:温度分布是汽缸变形的主要原因,长时间运行后缸体会产生明显的不可逆规律性变形。

适用于多种一次调频技术及工况变化的抽汽凝汽式汽轮机数学模型

火电机组是目前电力系统中重要的调频资源,其一次调频能力与汽轮机动态密切相关,但现有汽轮机动态数学模型无法准确反映火电机组在多种一次调频技术以及工况变化情况下的一次调频能力。为准确描述火电机组真实的一次调频动态,该文对汽轮机本体、回热抽汽管道及回热加热器的动态耦合特性进行机理分析,建立适用于主汽阀调节、凝结水节流和高加给水旁路调频技术的汽轮机动态模型;基于机组结构数据及分布式控制系统实测数据,提出跟随工况变化的模型参数在线确定方法;最后,以实际600MW机组为例进行模型验证与仿真分析。结果表明,汽轮机输出功率会受到汽轮机本体和回热系统动态耦合特性的重要影响,且不同工况下机组一次调频能力存在明显差异。该文模型能更准确地描述不同一次调频技术方案及不同运行工况下汽轮机的动态响应特性。

变几何涡轮燃气轮机总体性能研究

为深入了解变几何涡轮对燃气轮机的总体性能影响机理,通过部件法对燃气轮机进行建模,然后分别改变高压涡轮、中压涡轮和动力涡轮的第一级导向器喉道面积,在不考虑导叶两端调节机构和导叶间隙等对涡轮效率影响情况下,对燃气轮机总体性能的变化情况进行了系统地分析,并得出各截面的总温与总压变化情况。结果表明:在采用保持高压涡轮入口总温恒定的控制规律时,增大燃气轮机的高压涡轮流通能力,燃气轮机输出轴功率与耗油率均不断增加,高压涡轮流通能力增加10%,输出轴功率与耗油率分别上升2.83%与1.13%;增大燃气轮机的中压涡轮流通能力,导致燃气轮机输出轴功率降低,耗油率上升,中压涡轮流通能力增加10%,输出轴功率降低9.96%,耗油率上升3.63%;动力涡轮流通能力增加,燃气轮机输出轴功率先上升,后有小幅下降,耗油率增大,动力涡轮流通能力变化量从0增加到10%,输出轴功率降低0.05%,耗油率增加2.01%。

高压涡轮动叶叶尖掉块对气动性能及振动的影响

【目的】高压涡轮损伤条件下运行状态对燃气轮机性能和振动会产生一定影响,而目前准确评估整机是否可以继续服役的手段较为缺乏,为此开展高压涡轮动叶叶尖凹槽磨损掉块对气动性能及振动变形的影响研究。【方法】采用三维数值仿真方法,以原动叶完整叶尖凹槽结构为基准,通过仿真分析了5种不同叶尖凹槽掉块形状对高压涡轮典型气动性能及动叶振动特性的影响规律。【结果】动叶叶尖凹槽叶盆侧掉块,叶背侧掉块,尾缘掉块,叶盆和尾缘同时掉块,叶盆、叶背和尾缘同时掉块,分别造成高压涡轮效率下降0.44%、1.6%、0.03%、0.67%、3.2%;不同动叶叶尖凹槽形状对动叶的振动变形影响较小,尾缘掉块会减小动叶的变形。【结论】综合气动性能及振动变形的影响分析,对于动叶叶尖凹槽的叶盆掉块、尾缘掉块或两者同时掉块的叶片可以继续使用,而对于叶背掉块及盆背侧和尾缘同时掉块的叶片建议不再使用。

基于再热器再循环冷却技术的高压供汽方案探讨

在火电机组深度调峰成为常态化运行的前提下,对机组工业供汽的改造提出了更高的挑战。针对660 MW超临界机组高压供汽改造需求,提出以再热器再循环冷却技术为核心的3种供汽方案,并通过变工况热力计算分析方案的可行性及经济性。计算结果表明:30%及以上额定发电负荷在满足单机200 t/h、6.0 MPa、480℃供汽需求时,3种方案均可保证再热器在不超温的工况下安全运行,大幅提高机组宽负荷高压供汽能力;为了避免再热器出口流速超速,还需中调门配合参调运行,通过提高再热蒸汽压力以降低再热蒸汽流速;随着负荷的降低,满足额定供汽流量下的再热器再循环流量就会增加,方案1和方案3全工况下再循环流量相差不大,而方案2的高低负荷下再循环流量的比值可达5倍以上;3种供汽改造方案,方案2最节能,方案3次之,3种方案每年可分别产生3951、4445、4178万元的经济效益,但在实施过程中,对方案的选取要综合考虑投资成本、运行维护量及节能收益等因素。

发动机HPT叶片失效分析及损伤发展趋势研究

基于某航空公司CFM56-7B发动机高压涡轮转叶前缘历史孔探数据,首先分析热障涂层失效原因,运用统计分析方法,确定高压涡轮转叶前缘涂层脱落失效分布模型;然后对高压涡轮转叶前缘损伤发展趋势进行回归分析并计算机队高压涡轮转叶前缘平均寿命。

65MW高压超高温一次中间再热汽轮机在炼焦余热发电的应用

随着世界各国对环保重视程度的提升,以及对“双碳”的要求,炼焦行业对煤气的回收、利用,完全可以使用在化工产品的生产、燃烧发电项目上,从根本上响应了绿色双碳的潮流。本文介绍了高压超高温一次再热汽轮机的特点,分析了该机组在炼焦余热利用发电的情况。

350 MW汽轮机高压调节阀阀位不跟踪指令问题的分析及处理

针对某350 MW汽轮机高压调节阀阀位不跟踪指令问题,通过分析阀门工作原理和阀芯组件受力情况,判断原因为阀碟与阀套氧化皮沉积、配合间隙减小,利用小修机会解体阀门验证了判断并一次性解决了问题,对同类型机组高压调节阀卡涩、关闭问题分析处理具有一定借鉴意义。

燃气轮机压气机进气滤网高压差原因分析及解决对策

杂质对于燃气轮机压气机的运行会形成较多的不利因素,严重的会威胁到压气机的运行环境。为此提出对燃气轮机压气机进气滤网高压差原因分析及解决对策。简述了燃气轮机压气机运行及性能,从自清反吹系统失灵,杂物、污染物过多以及滤网材料、结构问题等3个方面,对进气滤网出现高压差原因进行分析。针对原因对其进行多层级控制空气流量,定期清洗、更换滤网,自清反吹系统周期性维护。在此基础之上,设定优化压气机材料和结构,并采用安装自适应实时高压差报警设备来进行高压差的控制巩固,稳定燃气轮机压气机的运行环境,延长使用寿命。

裂解气压缩机技术更新与节能探讨

对某乙烯装置裂解气压缩机GB-201存在的操作难度大、压缩机效率低、能耗高等问题进行分析发现,机组存在服役时间长、机体内密封不严和油环老化、内部窜气、三段出口超压等设备隐患,为此,采用抽汽量大的高效透平驱动机及高效三元叶轮压缩机,对压缩机组及附属设备进行整体更新。改造后,在相同工况下,压缩机效率明显提高,有效改善了装置的能耗,为乙烯装置裂解气压缩机解决此类问题提供了宝贵的经验。