【作者】 卫琛喻；

【导师】 臧述升；

【作者基本信息】 上海交通大学 ， 动力机械与工程， 2014， 博士

【摘要】 能源是整个世界发展和经济增长最基本的驱动力。随着世界经济的发展、世界人口的剧增和人民生活水平的提高，世界能源消费量持续增长，能源问题的重要性日益突出。加湿工质是提升燃气轮机效率与输出功率的一个有效途径。湿空气透平（Humid air turbine，HAT）循环是新型动力循环的代表，具有效率高、比功高、单位投资成本低、燃烧室氮氧化物（NOx）排放低、输出功率受环境条件影响小以及与联合循环相比变工况性能更出色等优点。然而，目前国内外对HAT技术的研究还不够充分，尤其缺少HAT循环的试验研究，试车数据更为稀缺。因此，本文将通过试验研究对HAT循环性能的仿真计算结果进行验证，并由仿真计算对试验方案提出修正和改进。能够提高对HAT循环性能的理解和认识，是HAT循环燃气轮机技术应用到实际机组和系统的基础。本文首先研究了燃气轮机性能仿真技术以及SJGT燃气轮机性能仿真软件的开发。研究了燃气轮机性能计算方法以及软件实现，包括热物性研究中的变比热法、稳态性能研究中的记忆时序性迭代法和嵌套式多层迭代的实现以及动态性能研究中变偏微分系数偏差线性化方法。分析了SJGT软件的构架和功能，以及该软件五大建模特色：多输入多输出计算模块、通用部件模块库、拖曳方式建模、动态链接库技术以及友好人机交互界面。以SJGT软件为平台，对燃气轮机进行了详细的部件级建模，特别考虑了压气机抽气模型和涡轮冷却模型，使仿真系统更加逼近真实系统。最后对各部件模块进行汇总，并创建模块库，为燃气轮机的性能研究打下基础。本文自主设计并建立了一套分离式的分轴燃气轮机试验装置，并通过加装饱和器空气湿化系统构成了HAT循环分轴燃气轮机试验装置。通过试验研究的方法来考察HAT循环在湿空气作用下对系统总体性能的提升，观察含湿量的变化对燃气初温、输出功率和循环效率等一些主要性能参数以及污染物排放情况的影响规律。HAT循环分轴燃气轮机性能试验主要分为两个工况进行：（1）将燃油量控制在48kg/h的等燃油控制试验工况；（2）将涡轮进气温度控制在650℃的等燃气初温控制试验工况。研究结果发现，空气加湿作用能够立即对HAT循环性能造成影响，饱和器出口处的含湿量是HAT循环性能研究中的一个重要参数。当燃油量保持不变，增加含湿量能够降低燃烧室燃烧温度，降低NOx的排放，并且由于蒸汽的加入增加了涡轮的工质流量，使得燃气轮机的输出功率也有所提升。当燃气初温保持不变时，系统中含湿量的增大可以大幅度提升HAT循环燃气轮机的输出功率。这表明，在燃气初温限制不变的情况下，HAT循环能够通过对燃气轮机循环进行革新来改善燃气轮机性能。基于HAT循环分轴燃气轮机试车试验研究，本文还对HAT循环分轴燃气轮机的总体性能进行了理论性研究。通过对分轴燃气轮机模型进行在更改工质热物性计算方法、添加饱和器模型、修正燃烧室模型等方面的改型，得到HAT循环分轴燃气轮机性能计算模型。通过模拟计算结果与试车试验结果的对比研究，可以发现两者吻合较好。结果表明：含湿量的变化对HAT循环燃气轮机的比功影响巨大。在现有试验条件范围内，增大含湿量能大幅度提高循环比功，更高的含湿量能为循环带来更好的热效率和热经济性，而且增大含湿量能够增大压气机喘振裕度，提高压气机运行的安全性。为了进一步了解HAT循环的潜力，本文还对现有HAT循环试验系统进行了改进，通过添加回热器、经济器和后冷器以构成更完整的HAT循环分轴燃气轮机系统。研究结果表明，在π=3.0和π=2.5工况下，对现有HAT循环、回热HAT循环和回热后冷HAT循环这三种HAT循环性能的比较分析后，发现回热HAT循环是三者中循环效率最高的一种循环，也是最节能环保的一种循环；当饱和器液气比在0.85~1.2范围内，增加饱和器液气比能够增大饱和器出口湿空气的含湿量，提高HAT循环的比功和热效率。但是，液气比会受到试验装置的尺寸、管道流量和水箱大小的限制；回热器回热度的增加有助于燃烧过程的进行，使系统更省油，同时提高HAT循环的热效率降低排烟温度。综合考虑回热器尺寸和HAT循环性能之后，本文在改型HAT循环的设计中，选取回热度为0.6；在HAT循环中设置后冷器的目的是降低饱和器入口处压缩空气的温度，然而对于现有试验台而言，提升后冷器出口空气温度将增大湿空气含湿量，循环比功和热效率将会增大，耗油率下降，排烟温度降低。因此对现有试验台而言，不推荐在系统的改进设计中加入后冷器。在对HAT循环分轴燃气轮机的性能有了较为全面的了解之后，本文对发电系统三轴燃气轮机的变工况性能和包括起动过程在内的动态性能进行分析，对甩负荷情况下的控制策略进行了深入研究，并开展了HAT循环技术在三轴燃气轮机上的应用性研究。研究结果表明，三轴燃气轮机在带动螺桨负载和带动恒速发电负载下的变工况性能相差不大；相比较带动螺桨负载和带动恒速发电负载的三轴燃气轮机系统，后者在低工况运行时低压压气机的喘振裕度要大于前者，但两者都应在低压压气机上采取旁通放气的方法来避免喘振。发电系统三轴燃气轮机在甩负荷情况下的动态性能仿真实验研究表明，串级控制系统相比单回路控制系统和前馈反馈控制系统具有更快速的响应特性以及更好的鲁棒性和稳定性。三轴燃气轮机动态过程的仿真实验，实验结果能够用于发动机的起动控制过程的分析和优化，具有重要的工程应用价值。对比简单循环、间冷回热循环、间冷回热HAT循环和间冷后冷回热HAT循环的三轴燃气轮机总体性能，结果表明，间冷回热HAT循环三轴燃气轮机功率输出能力最强，是简单循环三轴燃气轮机的2.73倍，间冷回热循环的1.74倍；间冷回热HAT循环具有非常高的循环效率，将近50%左右，耗油率均相对较低，经济性能好；间冷回热循环的排烟温度相对最低，从环保角度考虑为最优。在后冷器加入间冷回热HAT循环之后，虽然循环效率略有上升，排烟温度略有下降，但是会引起输出功率下降较多，降幅达到11.2%。更多还原

【Abstract】 Energy is the basic driving force of development and economic growththroughout the world. With the development of world economy, the rapid increase inworld population and improve of people’s living standards, the world’s energyconsumption continues to grow, the importance of energy issues have becomeincreasingly prominent. Humidifying working fluid is an effective way to enhance theefficiency and power output of gas turbine. Humid air turbine (HAT) cycle is arepresentative of the new power cycle. The advantages of HAT cycle including highefficiency, high specific work, low unit investment costs, low combustion nitrogenoxide (NOx) emissions, low impact of power output by environmental conditions, andgood off-design performance. However, the current domestic and internationalresearch on the HAT technology is not sufficient. It seems to be particularly lack ofHAT cycle of experimental research and the test data is more scarce. Therefore, thisthesis will study HAT cycle performance using the method of combining theexperimental research and theoretical study. Improving understanding and awarenessof the HAT cycle performance is the base of applying HAT cycle gas turbinetechnology to the actual units and systems.The gas turbine performance simulation technology and SJGT gas turbineperformance simulation software development were first studied. The gas turbineperformance calculation method and software implementation were studied, includingthe study of thermal properties of variable specific heat, the memory sequentialiterative method and the variable partial differential coefficients deviationlinearization method. The structure and function of the SJGT software were analyzed,as well as five of the software modeling features: multi-input multi-output calculationmodule, common parts module library, dragging modeling, dynamic link librarytechnology and a friendly man-machine interface. Using SJGT software, the detailedcomponent level model of gas turbine was carried on, especially considering thecompressor air-extraction model and turbine cooling air-injection model. Finally, thecomponent modules were gathered and the module library was created, which laid thefoundation for the research of the performance of gas turbine.Then, a test investigation on Humid Air Turbine (HAT) cycle was conducted on asmall-size two-shaft gas turbine test rig. The test rig was made up of a centrifugalcompressor, a centripetal turbine, an individual direct flow flame tube, a free power turbine, a dynamometer and a saturator with structured packing. The goals of thisthesis were to study the gas turbine overall performance improvement in HAT cyclesuch as the turbine inlet temperature, power output and cycle efficiency. The effect ofthe humid air on pollutant emission was also examined.Two different test conditions were taken into account for the test investigation: inthe first case, the fuel flow rate was kept constant at48kg/h by the control system,while in the second case, the turbine inlet temperature was kept constant at650℃.The results show that the air humidification can immediately affect the performanceof HAT cycle. The saturator outlet humidity ratio is an important parameter in thestudy of HAT cycle performance. When the fuel flow rate keeps constant, increasinghumidity ratio can decrease the combustion temperature, reduce the discharge of NOxand increase the power output due to the increase of flow rate of working fluidthrough the turbine. When the turbine inlet temperature keeps constant, increasinghumidity ratio will substantially increase the power output in HAT cycle gas turbine.It provides an alternative to improve gas turbine performance without being restrictedby a higher TIT depending on the development of material technology.Retrofit design from two-shaft gas turbine to HAT cycle two-shaft gas turbinecontains changing calculation method of working medium thermal physical property,adding the saturator model and modifying the combustion model. Based on the gasturbine parts characteristics and test conditions, the off-design performance of HATcycle was calculated and its results were coincident with the test ones. The studiesshow that the humidity ratio of the HAT cycle has a huge impact on the specific workof gas turbine, increasing the humidity ratio will greatly improve the cycle specificwork and the thermal efficiency. Increasing the humidity ratio can also increase thecompressor surge margin, which improves the compressor operation safety.In order to further understand the potential of HAT cycle, improved design on theexisting HAT cycle test system was studied, by adding the regenerator, economizerand aftercooler to form a more complete HAT cycle two-shaft gas turbine system.Research shows that in theπ=3.0andπ=2.5working conditions, the regenerativeHAT cycle shows the best performance and the most energy conservation among theexisting HAT cycle, the regenerative HAT cycle and the regenerative HAT cycle withaftercooler. Increasing liquid-gas ratio of saturator can increase the humidity ratio andimprove the cycle specific work and the thermal efficiency. However, the liquid-gasratio will be restricted by the size of the test unit, pipe flow and the tank size. Theincrease of the heat regenerator efficiency contributes to the combustion process, makes the system more fuel saving, and reduces the exhaust temperature. Afterconsidering both the size of regenerator and the HAT cycle performance, theregenerator efficiency is set to0.6. The purpose of setting up the after-cooler is toreduce the saturator inlet air temperature. However, increasing after-cooler outlet airtemperature will increase the humidity ratio, enhance cycle specific work and raisethe thermal efficiency, also reduce fuel consumption rate and decrease exhaust gastemperature as well. Therefore, the after-cooler is not recommended to be added to theimproved design system.Finally, the off-design performance and dynamic performance of the three-shaftgas turbine in power generation system of were analyzed. The thesis placed emphasison study of the control strategy in the case of load rejection. At last, the research onapplying HAT technology to the three-shaft gas turbine was discussed. The resultsshow that the off-design performances of three-shaft gas turbine driving the constantspeed load and the propeller load were similar. Compare the compressor performancebetween the propeller load system and the constant speed load system, compressorsurge margin of the latter system is greater than the former one. In the powergeneration system, single-loop control system, feedforward feedback control systemand cascade system were assessed in order to control the engine in the case of loadrejection. According to the results, the cascade control system is most satisfactory dueto its fastest response and best stability and robustness. The simulation experimentalresults of the gas turbine starting progress have the important value of engineeringapplication. Comparison is made among the general cycle, the regenerative cycle withintercooler, the regenerative HAT cycle with intercooler and the regenerative HATcycle with intercooler and aftercooler. The research shows that the regenerative HATcycle with intercooler is most optimal cycle, which performs the highest power outputof65703kW, relatively high cycle efficiency of49.03%and the lowest specific fuelconsumption of0.172kg/kWh.更多还原