湿燃气透平叶片热流固耦合换热特性的数值研究

为评估湿空气透平循环中湿燃气对透平叶片燃气侧换热特性的影响,以及湿空气对透平叶片冷却效果的影响,以C3X叶片为例,采用热流固耦合的数值计算方法,研究了湿燃气含湿量对透平叶片表面温度和传热系数的影响,对比分析了干空气与湿空气冷却效果的差异.同时在研究范围内给出了透平叶片燃气侧传热系数的无量纲关系式,为湿化燃气轮机透平叶片的优化和冷却结构设计提供参考.结果 表明:湿燃气含湿量对透平叶片燃气侧的流动性能基本无影响;当湿燃气含湿量从0 g/kg增加到150 g/kg,主流进口温度为1473 K时,透平叶片表面平均传热系数增加10％,且增加幅度随着主流进口温度的升高而增大,叶片表面最高温度平均提高10 K;与干空气相比,湿空气作为冷却工质时的叶片表面温度更低,冷却效率更高,且冷却效率随着湿空气合湿量的增加而提高.     

空气冷却燃气透平特性算法的研究

基于现代空气冷却燃气透平具有大冷却空气质量流量和跨音速的工作特点,对燃气透平的通流模型进行了改进,推导出适用于空气冷却燃气透平特性计算的通流模型,同时扩展了其适用范围.将通流模型和损失模型结合起来,利用所建立的性能计算公式,使用Matlab编程得到一套适用于变工况下空气冷却燃气透平特性的计算软件,并且通过多台燃气透平进行性能验证.结果表明:这套空气冷却燃气透平特性计算方法具有较高的精确性.     

注蒸汽燃气轮机循环工质热力性质研究

本文对注蒸汽燃气轮机循环中的工质,首先建立了燃气—蒸汽混合物(以下简称湿燃气)的理想模型;据此确立了湿燃气热力性质计算的二次线性插值方法。采用该方法,编制了供工程实用的湿燃气热力性质表及与之配合使用的理想水蒸汽表。     

工质加湿后简单燃气涡轮循环的动态响应

在传统燃气轮机循环的动态仿真研究中，对涡轮部件的处理一般都采用涡轮特性图或曲线的方法来完成；但如果进入涡轮的工质发生变化，由纯燃气变成高温高压高湿的燃气，那么涡轮特性图或曲线在无法获得的情况下要建立湿工质循环的动态仿真模型，对涡轮部件需作特殊处理。本文根据涡轮的工作原理建立了基于逐级计算的涡轮部件性能仿真模块：利用此涡轮模块，搭建完成了发电用简单燃气轮机循环动态仿真模型，同时燃烧室考虑注湿，计算在不同注湿情况下涡轮部件的性能变化以及整个循环的动态响应过程。     

带有冷气掺混的三级透平气动性能数值研究

借助NUMECA数值仿真软件,以某型燃气轮机的三级透平作为计算模型,对其在冷却气体掺混前后的流场进行了数值模拟。考虑到工质物性的影响,采用了变比热高温燃气作为计算工质。同时,针对燃气轮机透平进口的变工况问题,选取不同的透平进口总压值进行数值计算。结果表明,冷却气体的加入使得级损失增大,每列叶片流道出口速度或相对速度减小,下游叶片进口气流角减小;在三级透平冷气掺混时改变进口总压值,每列叶片流道的进口气流角几乎不变,除第三级动叶的激波损失与尾迹损失增大外,其余叶片流道的能量损失变化不明显。     

高温气冷堆氦气透平循环工质的热物性

在高温气冷堆氦气透平直接循环中,氦气既是堆芯的冷却剂,又是循环工质。氦气热物性数据来源多样且互相不一致,对目前应用较多的5种氦气热物性参数计算方法进行了比较分析。     

跨音速透平特性计算

在分析及计算燃气轮机装置变工况性能时,需要知道透平特性。利用综合的试验数据定性地估算多级跨音速透平特性是一种最简便的方法。本文主要介绍多级跨音速透平特性计算的程序设计,对计算方法和损失模型只作一般讨论。文末,结合实例,对JB公司PG5331燃气透平及斯贝发动机高压透平进行了计算。本程序在DIS—21型电子计算机上计算一个二级跨音速透平特性约一小时。     

燃气透平废热利用实例

本文简单介绍透平废气的特点和透平废热利用实例。一、燃气透平废气特点燃气透平是在1300～1500℃的温度范围内工作的热机,其废气温度很高,如透平入口温度为1300℃,则废气温度为650℃,如入口温度为1000℃,则废气温度为470℃。燃气透平废气压力通常高达数百毫米汞     

适用于燃气STIG循环中湿燃气的状态方程

将燃煤气的ＳＴＩＧ循环中湿燃气当作实际气体处理，利用两项维里方程的 对比态形式，建立了湿燃气的状态方程，用此状态方程及余函数修正法计算了湿 燃气的热力性质，并与按理想气体计算的湿燃气的热力性质进行了比较。     

地面管线蒸汽干度计算模型及影响因素分析

为实现稠油热采地面管线蒸汽干度准确预测,分析其对采油效率的影响,建立了湿蒸汽在地面管线内流动的热损失和压降耦合模型,采用微元法获得地面管线蒸汽干度拟合方程,研究了不同因素对水平管线沿程蒸汽干度的影响,结果表明:湿蒸汽计算值与拟合值相对误差均在10~(-6)～10~(-5)数量级,线性拟合方程可进行地面管线任意截面蒸汽干度预测;降低注汽锅炉出口温度和压力,增加注汽流量,提高初始蒸汽干度,可有效提高地面管线末端注汽井口的蒸汽干度。为稠油热采地面管线注汽系统的评价与优化提供理论参考。     

Performance analysis of open cycle gas turbines

In this study, the performance of ideal open cycle gas turbine system was examined based on its thermodynamic analysis. The effects of some parameters, such as compressor inlet temperature (CIT), pressure ratio (PR) and the turbine inlet temperature (TIT), on the performance parameters of open cycle gas turbine were discussed. The turbine net power output, the thermal efficiency and the fuel consumption of the turbine were taken as the performance parameters. The values of these parameters were calculated using some basic cycle equations and variables values of thermodynamic properties. Other variables such as lower heating value, combustion efficiency and isentropic efficiencies of compressor and turbine were assumed to be constant. The result showed that the net power output and the thermal efficiency increased by a decrease in the CIT and increase in the TIT and PR values. If it is aimed to have a high net power output and the thermal efficiency for the turbine, the CIT should be chosen as low as possible and the TIT should be chosen as high as possible. Copyright © 2008 John Wiley & Sons, Ltd.     

Novel and optimal integration of SOFC-ICGT hybrid cycle: Energy analysis and entropy generation minimization

Integrating fuel cells with conventional gas turbine based power plant yields higher efficiency, especially solid oxide fuel cell (SOFC) with gas turbine (GT). SOFCs are energy efficient devices, performance of which are not limited to Carnot efficiency and considered as most promising candidate for thermal integration with Brayton cycle. In this paper, a novel and optimal thermal integration of SOFC with intercooled-recuperated gas turbine has been presented. A thermodynamic model of a proposed hybrid cycle has been detailed along with a novelty of adoption of blade cooled gas turbine model. On the basis of 1st and 2nd law of thermodynamics, parametric analysis has been carried out, in which impact of turbine inlet temperature and compression ratio has been observed on various output parameters such as hybrid efficiency, hybrid plant specific work, mass of blade coolant requirement and entropy generation rate. For optimizing the system performance, entropy minimization has been carried out, for which a constraint based algorithm has been developed. The result shows that entropy generation of a proposed hybrid cycle first increases and then decreases, as the turbine inlet temperature of the cycle increases. Furthermore, a unique performance map has also been plotted for proposed hybrid cycle, which can be utilized by power plant designer. An optimal efficiency of 74.13% can be achieved at TIT of 1800 K and r_p,c 20.     

GA-based design-point performance adaptation and its comparison with ICM-based approach

Accurate performance simulation and estimation of gas turbine engines is very useful for gas turbine manufacturers and users alike and such a simulation normally starts from its design-point. When some of the engine component parameters for an existing engine are not available, they must be estimated in order that the performance analysis can be started. Therefore, the simulated design-point performance of an engine may be slightly different from its actual performance. In this paper, a Genetic Algorithm (GA) based non-linear gas turbine design-point performance adaptation approach has been presented to best estimate the unknown component parameters and match available design-point engine performance. In the approach, the component parameters may be compressor pressure ratios and efficiencies, turbine entry temperature, turbine efficiencies, engine mass flow rate, cooling flows, by-pass ratio, etc. The engine performance parameters may be thrust and SFC for aero engines, shaft power and thermal efficiency for industrial engines, gas path pressures and temperatures, etc. To select the most appropriate to-be-adapted component parameters, a sensitivity analysis is used to analyze the sensitivity of all potential component parameters against the engine performance parameters. The adaptation approach has been applied to an industrial gas turbine engine to test the effectiveness of the approach. The approach has also been compared with a non-linear Influence Coefficient Matrix (ICM) based adaptation method and the advantages and disadvantages of the two adaptation methods have been compared with each other. The application shows that the sensitivity analysis is very useful in the selection of the to-be-adapted component parameters and the GA-based adaptation approach is able to produce good quality engine models at design-point. Compared with the non-linear ICM-based method, the GA-based performance adaptation method is more robust but slower in computation and relatively less accurate.     

提高燃气轮机联合循环电站性能的优化方法

天然气联合循环机组因启停快、运行灵活性好、热效率高、排放清洁、建造周期短而倍受中国市场青睐.围绕如何通过燃气轮机进气系统、主机参数匹配、汽轮机冷端等参数优化来提高联合循环热效率是国内外学者研究的热点.以配有目前市场上最高性能等级燃气轮机的联合循环为研究对象,建立了以提高联合循环热效率为目标的热力计算和分析模型,提出了各段蒸汽压力及温度参数优化匹配方法,并进一步分析、讨论了燃料预热对联合循环热效率的影响.在综合考虑余热锅炉换热温差、汽轮机结构设计等制约因素下得到了一组蒸汽循环的优化参数配置.计算结果表明,相比直接沿用上一代蒸汽循环参数,使用该优化参数配置可大幅度提高联合循环效率,并且使用燃料预热可使循环性能得到进一步改善.     

Development of a gas turbine performance analysis program and its application

A general-purpose performance prediction program, which can simulate various types of gas turbine such as simple, recuperative, and reheat cycle engines, has been developed. A stage-stacking method has been adopted for the compressor, and a stage-by-stage model including blade cooling has been used for the turbine. The combustor model has the capability of dealing with various types of gaseous fuels. The program has been validated through simulation of various commercial gas turbines. The simulated design performance has been in good agreement with reference data for all of the gas turbines. The average deviations of the predicted performance parameters (power output, thermal efficiency, and turbine exhaust temperature) were less than 0.5% in the design simulations. The accuracy of the simulation of off-design operation was also good. The maximum root mean square deviations of the predicted off-design performance parameters from the reference data were 0.22% and 0.44% for the two simple cycle engines, 0.22% for the recuperative cycle engine, and 0.21% for the reheat cycle engine. Both the design and off-design simulations confirmed that the component models and the program structure are quite reliable for the performance prediction of various types of gas turbine cycle over a wide range of operations.     

Nonlinear design-point performance adaptation approaches and their comparisons for gas turbine applications

Accurate performance simulation and understanding of gas turbine engines is very useful for gas turbine manufacturers and users alike and such a simulation normally starts from its design point. When some of the engine component parameters for an existing engine are not available, they must be estimated in order that the performance analysis can be started. Therefore, the simulated design point performance of an engine may be slightly different from its actual performance. In this paper, two nonlinear gas turbine design-point performance adaptation approaches have been presented to best estimate the unknown component parameters and match available design point engine performance, one using a nonlinear matrix inverse adaptation method and the other using a Genetic Algorithm-based adaptation approach. The advantages and disadvantages of the two adaptation methods have been compared with each other. In the approaches, the component parameters may be compressor pressure ratios and efficiencies, turbine entry temperature, turbine efficiencies, engine mass flow rate, cooling flows, and bypass ratio, etc. The engine performance parameters may be thrust and SFC for aero engines, shaft power, and thermal efficiency for industrial engines, gas path pressures, temperatures, etc. To select the most appropriate to-be-adapted component parameters, a sensitivity bar chart is used to analyze the sensitivity of all potential component parameters against the engine performance parameters. The two adaptation approaches have been applied to a model gas turbine engine. The application shows that the sensitivity bar chart is very useful in the selection of the to-be-adapted component parameters, and both adaptation approaches are able to produce good quality engine models at design point. The comparison of the two adaptation methods shows that the nonlinear matrix inverse method is faster and more accurate, while the genetic algorithm-based adaptation method is more robust but slower. Theoretically, both adaptation methods can be extended to other gas turbine engine performance modelling applications.     

Nonlinear design-point performance adaptation approaches and their comparisons for gas turbine applications

Accurate performance simulation and understanding of gas turbine engines is very useful for gas turbine manufacturers and users alike and such a simulation normally starts from its design point. When some of the engine component parameters for an existing engine are not available, they must be estimated in order that the performance analysis can be started. Therefore, the simulated design point performance of an engine may be slightly different from its actual performance. In this paper, two nonlinear gas turbine design-point performance adaptation approaches have been presented to best estimate the unknown component parameters and match available design point engine performance, one using a nonlinear matrix inverse adaptation method and the other using a Genetic Algorithm-based adaptation approach. The advantages and disadvantages of the two adaptation methods have been compared with each other. In the approaches, the component parameters may be compressor pressure ratios and efficiencies, turbine entry temperature, turbine efficiencies, engine mass flow rate, cooling flows, and by-pass ratio, etc. The engine performance parameters may be thrust and SFC for aero engines, shaft power, and thermal efficiency for industrial engines, gas path pressures, temperatures, etc. To select the most appropriate to-be-adapted component parameters, a sensitivity bar chart is used to analyze the sensitivity of all potential component parameters against the engine performance parameters. The two adaptation approaches have been applied to a model gas turbine engine. The application shows that the sensitivity bar chart is very useful in the selection of the to-be-adapted component parameters, and both adaptation approaches are able to produce good quality engine models at design point. The comparison of the two adaptation methods shows that the nonlinear matrix inverse method is faster and more accurate, while the genetic algorithm-based adaptation method is more robust but slower. Theoretically, both adaptation methods can be extended to other gas turbine engine performance modelling applications.     

A methodology for improving the performance of molten carbonate fuel cell/gas turbine hybrid systems

In the present article a molten carbonate fuel cell (MCFC) system has been developed, modeled and implemented in Matlab language. It enables definition of the optimal operating conditions of the fuel cell, in terms of electrical and thermal performance, when it is a part of a hybrid plant composed of an MCFC system, a gas turbine and a possible heat recovery system. The thermal energy, which is recoverable from the adequately treated anodic exhaust gases, is utilized in a gas turbine plant to reduce its fuel consumption. Therefore, in the present article a methodology is illustrated to calculate the optimal values of some parameters characterizing the MCFC/gas turbine integrated system in terms of the electrical, first law and equivalent efficiencies. A choice is made among the sets of values of parameters investigated to improve the performance of the same integrated system according to its use (for the production of electric energy only or for the contemporary production of electric and thermal energy). Copyright © 2010 John Wiley & Sons, Ltd.     

Power generation using dedicated woody crops: thermodynamics and economics of integrated plants

Biomass will continue to play a significant and probably increasing role in the world's future energy mix, due to the strategic role it has for large availability, environmental concerns and technological advances. The raw biomass has a relatively high moisture content, requiring thermal drying processes in order to minimise stack losses.In this paper, integrated plant configurations burning dedicated woody crops for electric power generation and different options for pre-drying the biomass are discussed. Conventional indirect drying, using steam extracted from the turbine, and direct drying processes with hot gas turbine exhaust gases, are compared, assessing their influence on plant layout and performance. Moreover, a detailed economic analysis has been carried out for evaluating the levelized cost of the electricity produced, as well as the profitability of each plant configuration.The study shows that using the heat recovered from gas turbines for biomass drying enhances the feasibility of biomass-fired power plants, improving performance and reducing woody biomass crop requirements with respect to conventional configurations. The analysis also demonstrates that the proposed solutions allow reducing the cost of electricity produced and shorten payback periods.     

Thermodynamic assessment of advanced SOFC-blade cooled gas turbine hybrid cycle

This paper focuses on novel integration of high temperature solid oxide fuel cell coupled with recuperative gas turbine (with air-film cooling of blades) based hybrid power plant (SOFC-blade cooled GT). For realistic analysis of gas turbine cycle air-film blade cooling technique has been adopted. First law thermodynamic analysis investigating the combine effect of film cooling of blades, SOFC, applied to a recuperated gas turbine cycle has been reported. Thermodynamic modeling for the proposed cycle has been presented. Results highlight the influence of film cooling of blades and operating parameters of SOFC on various performance of SOFC-blade cooled GT based hybrid power plant. Moreover, parametric investigation has also been done to examine the effect of compressor pressure ratio, turbine inlet temperature, on hybrid plant efficiency and plant specific work. It has been found that on increasing turbine inlet temperature (TIT) beyond a certain limit, the efficiency of gas turbine starts declining after reaching an optimum value which is compensated by continuous increase in SOFC efficiency with increase in operating temperature. The net result is higher performance of hybrid cycle with increase in maximum cycle temperature. Furthermore, it has been observed that at TIT 1600 K and compression ratio 20, maximum efficiency of 73.46% can been achieved.