联合循环机组合理的变工况运行方式

讨论了联合循环机组在部分负荷下，燃气轮机的压气机采用可调静叶和汽轮机采用滑压运行，可以改善联合循环效率及提高汽轮机排汽干度，从而构成合理的变工况运行方式。文章最后讨论了由多台燃气轮机组成的联合循环中汽轮机的两种运行方式，并得出其中一种的运行方式为较好的结论。     

联合循环汽轮机高中压转子锻件的国产化研究

在引进、消化、吸收美国联合循环汽轮机高中压转子材料的基础上,针对国内大型转子锻件的实际生产情况进一步创新,采取3项技改措施,首次在国内研制出满足美国材料的要求并高于进口水平的联合循环汽轮机高中压转子锻件.对联合循环汽轮机高中压转子锻件成功国产化,不仅填补了国内空白,缩短转子锻件采购周期,降低机组的制造成本,同时也推动了燃气-蒸汽联合循环机组的国产化进程.     

600MW双背压机组运行中最佳背压的研究和应用

提出了600MW运行机组双背压凝汽器背压应达值的确定方法,并给出了计算模型。结合定洲发电公司600MW汽轮机组优化试验数据,计算得出了双背压凝汽器的最佳背压和循环水泵最佳运行方式。该方法可用于指导现场节能工作。     

联合循环电厂汽轮机供热运行的若干问题

国内某联合循环电厂由于汽轮机缺乏非设计工况下抽汽供热运行经验且需要参与电网调峰,经过对联合循环机组特性分析和现场运行数据的整理、优化,在保证机组安全的前提下,确定了汽轮机供热量和机组调峰能力,为指导运行人员操作和确定机组电网调峰能力提供了依据。     

联合循环用汽轮机的开发研制特点

针对联合循环的特点，简要介绍了如何进行联合循环用汽轮机的开发研制，使之既能满足用户的运行灵活性要求，提高机组效率，又能保证汽轮机产品质量，并降低成本。本文还用实例介绍了机组的设计应用和机型选取。     

联合循环用汽轮机的开发研制特点

针对联合循环的特点，简要介绍了如何进行联合循环用汽轮机的开发研制，使之既能满足用户的运行灵活性要求，提高机组效率，又能保证汽轮机产品质量，并降低成本。本文还用实例介绍了机组的设计应用和机型选取。     

配背压式汽轮机联合循环机组性能试验研究

为适应大容量供热需求,配背压式汽轮机联合循环机组在工业供热中得到越来越多的应用。该类机组的热力特性与联合循环纯凝机组不同,性能试验如何执行成为难题。结合配背压式汽轮机联合循环机组系统的设计及运行特点,在IPSEpro平台上自主开发热力模型,对其展开热力特性分析,并依据ASME PTC46性能试验标准,提出适用于该类型机组的性能试验方法。研究成果可为配背压式汽轮机的联合循环机组性能试验及合同中保证值的确定提供理论指导。     

联合循环抽凝背机组工况切换运行研究

联合循环抽凝背汽轮机可实现低压模块在线解列与并列功能来满足冬季采暖供热最大化的需求。通过对该类机组复杂的热力系统、本体结构以及轴系分析等方面的研究,确定工况切换策略,进行理论和试验研究,使机组的抽凝、纯凝和背压运行模式能在线切换,并安全稳定运行。研究成果为联合循环机组低压缸在线解列与并列运行设计提供了重要依据。     

燃气-蒸汽联合循环机组汽轮机抽凝转背压过程系统影响及安全性分析

对某电厂"一拖一"燃气-蒸汽联合循环机组汽轮机背压转抽凝工况切换过程中各系统的参数变化,对各系统的运行影响及安全性作出总结及分析,并提出若干建议。     

联合循环机组"炉跳机"事故原因分析及技术改造

采用“二拖一”运行方式的联合循环机组,当一台余热锅炉出现故障而跳炉时,如不及时处理会引起汽轮机误跳,进而使另一台余热锅炉跳炉。这几年,镇海联合循环机组此类事故频发,影响了机组的稳定运行。本文介绍该厂针对此类汽轮机误跳现象,在确保主设备安全的前提下,对锅炉部分保护逻辑进行了修改,以减少汽轮机误跳几率,确保汽轮机稳定运行。     

轴封蒸汽电加热器在国产联合循环汽机辅助系统配置中的作用

描述了国产联合循环汽轮机轴封系统优化的必要性和相关措施。在没有合适启动辅助汽源的条件下，通过配置轴封蒸汽电加热器，解决了轴封供汽温度偏低的问题。使汽轮机的启停次数使用寿命得以保证，并能大幅缩短锅炉冷、温态条件下的联合循环启动时间。     

西门子公司燃气轮机及联合循环汽轮机制造考察报告

通过对西门子公司柏林燃气轮机制造厂、米尔海姆汽轮机制造厂的考察,重点介绍了西门子公司F级燃气轮机V94.3A和与之配套的HE型联合循环汽轮机以及燃气轮机主要零部件的加工工艺特点,对国内制造厂有启发意义。     

Availability analysis of heat recovery steam generators used in thermal power plants

The combined-cycle gas and steam turbine power plant presents three main pieces of equipment: gas turbines, steam turbines and heat recovery steam generator (HRSG). In case of HRSG failure the steam cycle is shut down, reducing the power plant output. Considering that the technology for design, construction and operation of high capacity HRSGs is quite recent its availability should be carefully evaluated in order to foresee the performance of the power plant.This study presents a method for reliability and availability evaluation of HRSGs installed in combined-cycle power plant. The method’s first step consists in the elaboration of the steam generator functional tree and development of failure mode and effects analysis. The next step involves a reliability and availability analysis based on the time to failure and time to repair data recorded during the steam generator operation. The third step, aiming at availability improvement, recommends the fault-tree analysis development to identify components the failure (or combination of failures) of which can cause the HRSG shutdown. Those components maintenance policy can be improved through the use of reliability centered maintenance (RCM) concepts. The method is applied on the analysis of two HRSGs installed in a 500 MW combined-cycle power plant.     

Gas turbine turbocharged by a steam turbine: a gas turbine solution increasing combined power plant efficiency and power

A new design of a combined-cycle gas turbine power plant CCGT with sequential combustion that increases efficiency and power output in relation to conventional CCGT plants is studied. The innovative proposal consists fundamentally in using all the power of the steam turbine to turbocharge the gas turbine. A computer program has been developed to carry out calculations and to evaluate performance over a wide range of operating conditions. The obtained results are compared with those of combined cycles where the gas turbines are not turbocharged and the gas and the steam turbines have independent power exits; the advantages of the new design are stated.     

Modeling,numerical optimization,and irreversibility reduction of a dual-pressure reheat combined-cycle

Optimizing the gas-turbine combined-cycle is an important method for improving its efficiency. In this paper, a dual-pressure reheat combined-cycle was modeled and optimized for 80 cases. Constraints were set on the minimum temperature-difference for pinch points (PP_m), superheat approach temperature-difference, steam-turbine inlet temperature and pressure, stack temperature, and dryness fraction at the steam-turbine’s outlet. The dual-pressure reheat combined-cycle was optimized using two different methods; the direct search and the variable metric. A technique to reduce the irreversibility of the steam generator of the combined cycle was introduced. The optimized and the reduced-irreversibility dual-pressure reheat combined-cycles were compared with the regularly-designed dual-pressure reheat combined-cycle, which is the typical design for a commercial combined-cycle. The effects of varying the inlet temperature of the gas turbine (TIT) and PP_m on the performance of all cycles were presented and discussed. The results indicated that the optimized combined-cycle is up to 1% higher in efficiency than the reduced-irreversibility combined-cycle, which is 2–2.5% higher in efficiency than the regularly-designed combined-cycle when compared for the same values of TIT and PP_m. The advantages of the optimized and reduced-irreversibility combined-cycles were manifested when compared with the most efficient commercially-available combined cycle at the same value of TIT.     

Analysis of the dynamic characteristics of a combined-cycle power plant

Gas/steam combined cycle has already become a well-known and substantial technology for power generation due to its numerous advantages including high efficiency and low environmental emission. Many studies have been carried out for better performance and safe and reliable operation of combined-cycle power plants. A power plant is basically operated on its design conditions. However, it also operates on the so called off-design conditions due to the variation in a power load, process requirements, or operating mode. Therefore, the transient behavior of the system should be well-known for the safe operation and reliable control. In this study, dynamic simulation is performed to analyze the transient behavior of a combined-cycle power plant. Each component of the power plant system is mathematically modeled and then integrated into the unsteady form of conservation equations. Transient behavior was simulated when rapid changes and periodic oscillations of the gas turbine load are imposed. Time delay characteristic caused by the thermal and fluid damping is analyzed and overall time-response of the combined power plant system is shown.     

Possibilities for gas turbine and waste incinerator integration

The aggressive nature of the flue gases in municipal waste incinerators does not allow the temperature of steam in the boiler to rise above 400°C. An increase in steam temperature can be achieved by external superheating in a heat recovery steam generator positioned behind a gas turbine, so that steam of a higher energy content becomes available for electricity production. The paper addresses two basic schemes. In one case, steam generated at a waste-to-energy plant is superheated in a combined-cycle plant that operates in parallel. In the other case, the exhaust from a gas turbine plant is sent through a superheater section to the waste incinerator's boiler providing preheated combustion air. Performance of these configurations together with two modified schemes was analyzed in terms of efficiency, natural gas consumption and boiler surface area. An exergy analysis of the cases was carried out. The results showed that the integrated options can effect a substantial increase in efficiency. The hot windbox configuration was found the most effective solution, offering a smaller boiler surface area along with a moderate rate of natural gas consumption.     

国内首台660 MW二次再热机组启动与调试

二次再热是火电机组提高效率的有效手段,国内首台二次再热机组的成功投运,为今后火电项目的建设,提供了新的选项。文章介绍了东方二次再热汽轮机启动系统的配置、启动参数的选择以及机组的启动和调试中需注意的事项和存在的问题,为今后同类机组的投运和设计提供了参考。     

中小型汽轮机低真空供热的安全性分析

中小型汽轮机低真空供热可以节约能源，但对汽轮机本身的安全性会产生一定的影响。计算并讨论了汽轮机轴向推力随背压的变化特性；并利用该分析结果对营口第一热电厂CC12型汽轮机进行了低真空改造，分析了轴向推力、凝汽器冷却管膨胀量、汽缸膨胀量等的变化对汽轮机安全性的影响。该厂低真空供热后，机组运行良好。     

东方空冷600MW两排汽汽轮机的设计

在我国西北地区由于水资源严重短缺,而这些地区又富产煤,在我国以煤电为主的能源结构情况下,大力发展空冷机组是一条必由之路。国家已将建设大型空冷电站列入“十一五”规划纲要。我国空冷技术在20世60年代开始起步,经过多年的发展,在各个方面均取得了丰硕的成果,特别是在空冷汽轮机的设计方面积累了丰富的经验,同时随着国家对节能环保要求的进一步提高,开发高参数、大容量的高效空冷汽轮机已到了水到渠成的时候。该文就大型空冷600MW两排汽汽轮机设计中的关键技术如机型、容量、效率、末级叶片、排气装置、系统配置等进行论述。实践证明,东方空冷两排汽汽轮机组设计先进,可靠性高。