燃气轮机冷却技术综述

详细地阐述了对气膜冷却、内部强化换热以及热管冷却等的影响因素,目前的应用状况以及发展前景.重点集中在内部强化换热和热管冷却.本文可以使刚开始接触燃气轮机冷却技术的人员对冷却技术有个整体的了解,还可以对研究设计人员提供必要的参考依据.     

燃气轮机进气蓄冰冷却系统的运行优化

燃气轮机的输出功率受环境温度的影响,对燃气轮机的进口空气进行冷却,能提高其输出功率。当前工程中采用的是在夜间用电低谷期制冰蓄冷,白天用电高峰期融冰供冷保证最大出力的运行方式。本文在采用冰蓄冷的基础上,引入时间变量建立燃料消耗最少的积分型性能指标,在时变环境的意义下,对燃气轮机进气蓄冰冷却系统提出基于用户负荷和环境温度预测曲线的新的运行优化方式,并考虑负荷预测的不确定。通过建模仿真表明这一技术可行,具有进一步研究的价值。     

燃气轮机压气机喘振及其控制算法

压气机是燃气轮机的三大部件之一,它运行的安全、高效对燃气轮机性能至关重要。本文扼要地介绍了压气机喘振的影响因素,分析了压气机的性能曲线和喘振线;在此基础上针对压气机某一种喘振控制策略,分析其各种控制设定曲线和控制算法。通过以上两方面的介绍,希望对燃气轮机压气机的喘振防治有所帮助。     

Analysis of internal cooling geometry variations in gas turbine blades

The present investigation analyzes the effects of major geometrical modifications to the interior of a convection cooled gas turbine rotor blade. The main focus lies on the flow of the leading edge channels and the impact on the heat transfer. An experimental approach is performed with flow visualization via paint injection into water. Also numerical calculations are carried out in two sets, on the one hand water calculations accompanying the experiments and on the other hand conjugate heat transfer calculations under realistic engine conditions. The latter calculations are still ongoing delivering preliminary results. Five geometry configurations are investigated, three of them with differing turbulator arrangements in the leading edge channels. The operating point of the base configuration is set to Re = 50,000 at the inlet while for the modified geometries the pressure ratio is held constant compared to the base.     

Analysis of trigeneration plants: engine with liquid desiccant cooling and micro gas turbine with absorption chiller

The performances of two natural gas small‐scale trigeneration plants are dealt with in the paper. The two plants are part of a new cogeneration and trigeneration system laboratory at the Politecnico di Torino (Turin, Italy), which will be set up and exploited for scientific and technical purposes. The first plant has 126/220/210 kW electrical, heating and cooling capacities, respectively, and it is characterized by an innovative internal combustion engine (ICE) that has been coupled to a liquid LiCl–water desiccant cooling system. The other plant has 100/145/98 kW electrical, heating and cooling capacities and is composed of a micro gas turbine, coupled to a LiBr–Water absorption chiller. The aim of the paper was comparing the performances of the two plants from an energetic and economic point of view; the Primary Energy Savings are calculated for both installations through a commonly accepted methodology proposed by the European Union, and through another methodology, reported in literature, which seems more suitable to describe the energetic performances of trigeneration plants. The savings calculated with this second procedure result to be lower than those of the European Union methodology; moreover, the ICE installation always denotes higher performances with respect to the microturbine. From the economic point of view, it is evident that a fuel tax reduction for high‐efficiency cogeneration plants is an essential contribution for the support and development of these systems. Copyright © 2011 John Wiley & Sons, Ltd.     

微型燃气轮机涡轮背盘冲击冷却特性研究

受可靠性和成本制约,微型燃气轮机冷却技术的发展和应用一直较为缓慢,已成为其进一步提升热效率的主要瓶颈。针对此问题,提出了一种简单可靠的径流涡轮新型冷却技术-背盘冲击冷却,使用气热耦合的方法对该冷却技术的冷却特性进行了仿真研究。结果表明:背盘冲击冷却可以大幅降低径流涡轮背盘的温度。当冷却气体流量为主流的2%时,冷却流体温度从473.0降到323.0 K,背盘平均温度降低了143.0～202.0 K;当冷却温度为323.0 K时,冷却气体消耗量从主流质量流量的1%增加到4%时,背盘平均温度降低150.0～252.0 K。冷却流体流入主流后会对其产生一定的影响,每增加1%的冷却流量,涡轮机效率下降约1%。     

Brayton refrigeration cycle for gas turbine inlet air cooling

In this paper, a new approach to enhance the performance of gas turbines operating in hot climates is investigated. Cooling the intake air at the compressor bell mouth is achieved by an air Brayton refrigerator (reverse Joule Brayton cycle) driven by the gas turbine and uses air as the working fluid. Fraction of the air is extracted from the compressor at an intermediate pressure, cooled and then expands to obtain a cold air stream, which mixes with the ambient intake. Mass and energy balance analysis of the gas turbine and the coupled Brayton refrigerator are performed. Relationships are derived for a simple open gas turbine coupled to Brayton refrigeration cycle, the heat rejected from the cooling cycle can be utilized by an industrial process such as a desalination plant. The performance improvement in terms of power gain ratio (PGR) and thermal efficiency change (TEC) factor is calculated. The results show that for fixed pressure ratio and ambient conditions, power and efficiency improvements are functions of the extraction pressure ratio and the fraction of mass extracted from the air compressor. The performance improvement is calculated for ambient temperature of 45°C and 43.4% relative humidity. The results indicated that the intake temperature could be lowered below the ISO standard with power increase up to 19.58% and appreciable decrease in the thermal efficiency (5.76% of the site value). Additionally, the present approach improved both power gain and thermal efficiency factors if air is extracted at 2 bar which is unlike all other mechanical chilling methods. Copyright © 2007 John Wiley & Sons, Ltd.     

Mist film cooling simulation at gas turbine operating conditions

Air film cooling has been successfully used to cool gas turbine hot sections for the last half century. A promising technology is proposed to enhance air film cooling with water mist injection. Numerical simulations have shown that injecting a small amount of water droplets into the cooling air improves film-cooling performance significantly. However, previous studies were conducted at conditions of low Reynolds number, temperature, and pressure to allow comparisons with experimental data. As a continuous effort to develop a realistic mist film cooling scheme, this paper focuses on simulating mist film cooling under typical gas turbine operating conditions of high temperature and pressure. The mainstream flow is at 15 atm with a temperature of 1561 K. Both 2D and 3D cases are considered with different hole geometries on a flat surface, including a 2D slot, a simple round hole, a compound-angle hole, and fan-shaped holes. The results show that 10–20% mist (based on the coolant mass flow rate) achieves 5–10% cooling enhancement and provides an additional 30–68 K adiabatic wall temperature reduction. Uniform droplets of 5–20 μm are used. The droplet trajectories indicate the droplets tend to move away from the wall, which results in a lower cooling enhancement than under low pressure and temperature conditions. The commercial software Fluent is adopted in this study, and the standard k–ε model with enhanced wall treatment is adopted as the turbulence model.     

大型燃气轮机透平冷却空气量估算

大型燃气轮机透平冷却空气量一般难以直接获得。本文从燃机总体物质与能量平衡的角度,结合透平一级静叶的冷却模型,给出了一种估算大型燃气轮机冷却空气量的方法,并对GE公司系列燃气轮机和西门子公司V94．3燃气轮机冷却空气量进行了估算。结果表明采用本文的方法估算的燃气轮机透平冷却空气量是合理的。     

某燃气轮机涡轮叶片复合冷却结构优化设计

为了提高涡轮叶片设计效率,搭建了基于一维管网理论的iSIGHT优化设计平台,获得了叶片的优化结构,并对其进行三维仿真计算分析。研究表明：优化前后叶片的气动性能变化不大,总压损失仅在端壁处略有差别;优化后涡轮叶片的壁面温度分布更加均匀,壁面的最高温度降低,温度梯度减小,最大相对温差降低10%左右;在降低叶片热应力的同时相对冷却效率提高1.0%。     

M701F型燃气轮机中的冷却技术

本文介绍了M701F型燃气轮机冷却系统的组成、日本三菱公司在F系列或G系列燃气轮机上所采用的冷却技术及其应用情况,阐明了三菱公司研发的大型燃气轮机之所以能够安全稳定运行并具有很高的可靠性和热效率,采用先进的冷却技术是其成功的重要因素之一。     

Heat transfer measurement techniques of film cooling in gas turbine blades

An overview of the experimental techniques employed or developed for the measurement of local and mean heat transfer coefficients and adiabatic wall effectiveness from film cooled surfaces is presented. The scope of this work is confined to heat transfer techniques applied to film cooling of gas turbine blades, steady state and transient. The latter technique have significant advantages over the former in that it yields results at parameters duplicating those at the full-scale operating engine conditions, although the former technique offers simplicity.     

Mass transfer mesurement techniques of film cooling in gas turbine blades

This paper presents an overview of the analogous mass transfer experimental techniques that are used or developed for the measurement of local and mean heat-mass transfer coefficients and adiabatic wall effectiveness, chiefly for the film-cooled blades of gas turbines. The mass transfer techniques yield comprehensive results that are more difficult to obtain using the conventional heat transfer methods. They also provide results such that the errors associated with direct heat transfer methods are eliminated.     

闭式循环气轮机装置使用的无气体产生燃料

无气体产生燃料在AIP装置上的应用具有优势,如不会释放燃烧反应气体,不存在燃烧产物排放问题,不会形成排气尾迹。针对闭式循环气轮机装置使用的无气体产生燃料,提出了无气体产生燃料及其氧化剂选择和需满足的技术要求,给出了一些无气体产生燃料及其相应氧化剂的种类和性质,介绍了无气体产生燃料的燃烧方式和燃烧设备,描述了使用无气体产生燃料的闭式循环蒸汽轮机装置和燃气轮机装置的系统组成及工作原理,并对一些应用上问题进行了分析。     

燃气透平在大型乙烯改造中的应用

本文在对某常规68万t/a乙烯裂解装置的蒸汽平衡进行分析的基础上,结合乙烯装置的改造实际情况,提出了燃气透平、废热锅炉和蒸汽透平相组合的联合循环热功联产系统,并对燃汽蒸汽联合循环与过程的能量集成进行了全局夹点分析和联合系统的技术经济分析,结果表明改造后经济效益较为明显。     

燃气轮机内环水余热回收研究

通过对燃机内环水所携带热量的研究,设计换热器,论证了用内环水加热燃机天然气进气的可行性,从而达到回收内环水余热,节约能源的目的。     

Effect of various inlet air cooling methods on gas turbine performance

Turbine air inlet cooling is one of many available commercial methods to improve the efficiency of an existing gas turbine. The method has various configurations which could be utilized for almost all installed gas turbines. This paper presents a comparison between two commons and one novel inlet air cooling method using turbo-expanders to improve performance of a gas turbine located at the Khangiran refinery in Iran. These methods have been applied to one of the refinery gas turbines located at the Khangiran refinery in Iran. Two common air cooling methods use evaporative media or a mechanical chiller. The idea behind the novel method is to utilize the potential cooling and power capacity of the refinery natural gas pressure drop station by replacing throttling valves with a turbo-expander. The study is part of a comprehensive program with the goal of enhancing gas turbine performance at the Khangiran gas refinery. Based on the results, it is found that using turbo-expanders is the most economically feasible option and so is recommended to be utilized for improving gas turbine performance at the Khangiran refinery.     

西门子公司V94.3燃气轮机冷却空气信息推测

作为建立燃用低热值合成气的燃气轮机变工况模型的一个关键步骤，对西门子V94.3燃气轮机冷却空气参数及其分配进行了研究，试图从公开发表的燃气轮机功率、压比、排气温度、三亿透平初温等数据中推测出冷却空气量的分配规律。计算和推测所得到的冷却空气参数和分配规律与燃机净功率以及ISO温度基本吻合。     

PG6581B型燃气轮机冷却空气信息推测

作为建立燃用低燃值合成气燃气轮机变工况模型的一个关键步骤,本文对PG6581B燃气轮机冷却空气参数及其分配进行了研究,从公开发表的净功率、效率、排气温度等数据中推测出冷却空气量的分配规律,并利用文献中GE公司F级压气机特性曲线计算简单循环变工况性能,结果与实测数据基本吻合。     

发电用单轴燃气轮机动态模型研究

以某发电用单轴燃气轮机的控制系统为原型,利用Matlab／Simulink对该型单轴燃气轮机控制系统进行了仿真,仿真结果与实际物理过程相吻合,说明此模型可以用于单轴燃气轮机及其控制系统的研究。