基于胜利煤田高水分低热值褐煤特性,从搭建1∶1尺寸热态试验台验证大功率等离子点火技术点燃该煤种的可行性入手,通过冷态调平试验、逻辑优化、制粉系统启停参数优化、燃烧调整等,探索了能够可靠点燃胜利煤田高水分低热值褐煤的等离子启弧功率(最低电压、最低电流)、一次风温、一次风速、煤粉质量浓度等技术参数,研究了大功率等离子点火技术在国家能源集团胜利发电厂(以下简称国能胜利电厂)的现场调试及生产应用情况,分析了等离子发生器电流、一次风温、一次风速、煤质变化对其点火性能和燃烧稳定性的影响.结果表明:通过调整等离子电流、一次风温和风速,能够实现大功率等离子点火技术对胜利煤田高水分低热值褐煤的点燃和稳燃,实现了无油点火、无油稳燃在660 MW超超临界机组的应用.

某1750 MW大型汽轮机组在启动联调期间发生多起由振动引发的旁路调节阀(旁排阀)部件疲劳断裂情况,影响机组的安全运行.本文旨在揭示旁排阀流致振动机理及振动规律,为旁排阀结构优化和运行方式优化提供参考.通过对阀内介质流体动力学仿真分析,发现阀内介质存在明显的旋涡脱落和边界层分离现象,且随着阀门开度变化,流动特性发生显著变化.结合流体、结构动力学仿真结果及振动测试结果,开展了流固耦合综合分析.分析结果表明:阀内漩涡脱落激发的抖振是阀杆及连轴器断裂的主要原因,阀门结构优化改善了介质湍流及旋涡脱落程度,但是阀门在大开度下反复调节流量时,依然会激发阀杆及联轴器较高的振动水平;阀门大开度下激发的涡激共振是紊流罩破坏的主要原因.

A novel flat electron emission lamp (FEEL) was demonstrated using the porous silicon (PS) based electron emitter as the cold cathode, which is characterized by low vacuum requirement, convenient fabrication, simple structure, and low driving voltage. The favorable luminous brightness was obtained even the emission current density is only 13.86 μA/cm2 at the low driving voltage of 36 V. Compared with the conventional fluorescent lamp, the lower driving voltage and operation current density make the novel FEEL generate lower thermal effect and power consumption. It is easy to control the luminous intensity by changing the emitted electron kinetic energy which is adjusted by varying driving voltage. Moreover, since the environmentally hazardous mercury was replaced by the solid-state phosphor in this novel FEEL, many benefits also can be obtained such as safety, stability, environmentally friendly, and downsizing. Most importantly, because the PS can be directly fabricated by the simple wet etching process in the silicon wafer, our results also can open new perspectives for the realization of silicon-technology compatible fluorescence lamps with large fluorescence area operating at room temperature.

作为火电厂重要考核指标之一,厂用电率的高低直接反映出电厂能源的转换效率,也在一定程度上决定着机组的盈利能力.本文以国家能源集团示范工程胜利发电厂2×660MW高效超超临界燃煤间接空冷机组为研究对象,对其运行厂用电率指标从工程设计和生产运营两方面进行了综合优化和研究,旨在为同类型机组运行厂用电率的优化工作提供一些思路和可供借鉴的经验,以进一步提高火电机组运行经济性.

通过对某660 MW超超临界机组现有热力系统进行改造,在原有加氧点的基础上新增了高压加热器加氧点,开展了机组凝结水系统、给水及高压加热器疏水系统的全保护自动加氧(FPOT)技术应用试验.结果 表明,机组实施FPOT后,给水、凝结水pH值控制范围由原来9.2～9.4降低至9.0～9.2,给水溶解氧质量浓度稳定在5～20 μg/L,主蒸汽中无氧、高压加热器疏水溶解氧浓度基本控制在30～50 μg/L,实现了给水低浓度、精确加氧控制.在保持给水和高压加热器疏水低浓度溶氧的情况下,FPOT技术可抑制给水系统、高压加热器疏水系统流动加速腐蚀,有效缓解过热器、再热器氧化皮集中脱落风险,实现炉前给水系统、高压加热器汽侧的防腐目的.

A new research strategy that fixed the anodic electrical charge was proposed to investigate the combined effects of the anodization current density and anodization time on the porous silicon (PS) morphology and the cold emission properties. The microstructure of the PS was characterized by atomic force microscope and scanning electron microscope, and the electrical performance of the PS -based emitter was measured in vacuum. The experiment results show that the anodization current density is an outstanding parameter in controlling the PS morphology and emission characteristics than etching time. The electron emission measurement results demonstrate that 15 mA/cm(2) is an effective etching current density to improve the performance of the PS emitter at a fixed anodic electrical charge Q = 60 mA min. A modified quasi -ballistic electron drift model proposed in this work further demonstrated that PS layer including more silicon nanocrystallites with favorable interconnected property can significantly improve the field emission property since it could provide more and stable accelerating tunnels for electrons during the device operation. This work is helpful to clarify the combined role of the key anodization parameters on the PS micromorphology and also contribute to the fundamental understanding of the field emission mechanism of PS-based emitter.

从某电厂两台660 MW超超临界机组给水全挥发处理(AVT)存在的问题入手,分析了该技术造成的受热面沉积速率高、锅炉压差大、汽轮机氧化铁沉积、高加流动加速腐蚀(FAC)等问题的原因;介绍了该机组应用的给水全保护自动加氧(FPOT)技术的工艺流程,并评估该机组加氧稳定运行后高加疏水加氧效果、汽水系统含铁量及凝结水精处理运行周期变化;总结全保护自动加氧(FPOT)的优越性并提出了运行及维护建议,以期为同类型机组给水加氧处理提供借鉴.

火力发电厂运行人员培训工作具有周期长、难度大、质量要求高等特点,其培训效果直接关系着机组的安全、稳定、经济运行.本文分析了基建期电厂(胜利发电厂)当前生产准备运行人员培训中存在的问题,结合胜利发电厂生产准备现状,探索出了一种新的培训思路——"运行训练文件包"培训方式,并介绍了其在胜利发电厂的实际应用情况,以期为同类型基建期电厂运行人员的培训工作提供一些借鉴.

燃煤电厂生产准备运行人员培训是机组投产前,生产准备工作的核心内容之一.通常新建电厂在基建期对于集控运行人员的培训一股采用专业电力院校理论培训、同类型已投产电厂跟班学习两种培训形式.神华胜利发电厂2 ×66万千瓦机组建设项目是国家能源集团下属中国神华能源股份有限公司独资建设的大型坑口电厂,是“神华胜利煤电一体化”的主体项目之一.秉承“专业化、高标准”的总体要求,机组选用目前国内最先进的66万千瓦高效超超临界间接空冷燃煤凝汽式汽轮发电机组,采取了“两机一塔、五塔合一”“净烟气提水”“智慧电厂”“气垫输煤”和航空大功率等离子点火等世界先进生产工艺,以期建设成为具有市场竞争力、全寿命周期内综合效益最大化的超超临界、超低排放、超低能耗的“三超”电厂.为实现这一目标,神华胜利发电厂创新培训方式方法,以“运行训练文件包”方式提高对集控运行人员的科学化、专业化、精细化培训.

针对胜利电厂的现状提出了加装GCB的优化方案,并对GCB的优势从经济性、运行维护便利性、可靠性、优化保护配置等方面进行了全面的分析,为同类型工程设计提供了一个可行方案.

某新建600MW机组锅炉储水箱溢流管自投运以来支吊架即工作不正常,管道膨胀不畅,按照原设计对管道支吊架进行调整后又出现了新的问题.对此,采用应力分析软件对该管道进行应力校核计算,计算结果表明支吊架载荷设计错误主要原因.根据计算分析结果,重新调整吊架载荷分配,锅炉启动后,管道运行良好,保证了机组安全生产的需要.

Using numerical calculation method by CAESAR Ⅱ V 5.0 pipe stress analysis program,the displacement change of different wall thickness of high temperature reheat steam pipelines in a power plant was simulated,and the constant of constant force hanger was measured in the field.The results showed that the main causes of abnormal thermal displacement of high temperature reheat pipe were due to deviation of pipe wall thickness and unqualified constant of constant force hanger.After adjusting for the hanger,the sinking problem of pipe was resolved.

Through analysis of steam and water pipeline vibration cases occurred in power plants,the related frequency spectrum characteristics for vibration of steam and water pipe-lines have been summarized up,and some recommendations for vibration remedy being given.Study shows that the repeatability and stability of major vibration componts in the frequency spectrum graph are better,and the comparability of frequency spectrum graph at same measuring point is higher.The principal vibration boasts periodic vibration behavior;the frequency spectrum graph of resonance vibration is more simple,the spectrum line of principal vibration is outstanding,and that of other vibration being very week;the forced vibration often hasn't principal vibration frequency,in the event of vibration velocity surpassing the set standard,and the pipeline being drastically vibrated,the vibration velocity of several major frequencies may be not high.The remedy of vibration can obtain good result in alleviating vibration when combining with vibration mode analysis for pipelines.

Compensator in the condensate water pipline of a 300 MW power station unit was continually deformed into cracks.At the same time,supports and hangers of the pipline were draged inclined,and end cap of the heat well connected with the condenate water pipline was also deformed observably.Such a situtation would lead to accident of the power units.To solve this problem,stressing model of the entrance pipline of condensate water was estabilished.Moreover,load on the pipline,its stress and displacement,and also the endpoint thrust were calculated.Results show that,the basic reason for the problems mentioned above is not considering the inner pressure of the medium in pipeline design which will cause the extension of compensator along its axis direction.Suggestion that appropriate measures should be adopted to eliminate the effect of inner pressure of pipeline on the compensator when the pipeline with compensator is designed is given.

In order to determine the cause leading to fracture occurred on screwed hanging rod of PHB type constant force suspension bracket in one power plant,macroscopic analysis,mechanical performance test,metallographic examination,and scanning electronic microscope test have been carried out for the fractured screwed hanging rod.Results show that the main cause resulting in fracture of the screwed hanging rod is the very low impact toughness of material,being extremely brittle material,and far lower than the allowed value specified in the standards,hence,the fracture occurred under action of alternating tensile load and bending load.Besides,the PHB type suspension bracket has structure defects in design,it is recommended to amend and perfect the standard JB/T8130.1-1999.

Through preventive process of vibration occurred on medium pressure feed-water pipeline on conventional island in one nuclear power plant,the mutual relationship between the frequency spectrum of vibration and the result of modal calculation has been studied,a preventive scheme of vibration being worked out according to this,and the effectiveness of vibration reduction being evaluated.Combined with the response curve of excited frequency,a vibration-preventing principle for pipelines in power plants has been analysed and sammarized out as in the following:on suitable locations on the pipeline,vibration-preventing device has to be installed,making the natural frequency and oscillation mode at one stage of the pipeline to be eliminated,or making th natural frequency and the oscillation mode to be enhanced to n+1 stage,the main vibration response at one stage of the pipeline will disappear.

Rigid strut have found wide application in control of pipe vibration duo to its good vibration reduction and economical efficiency.A study is conducted on the pipes of a power plant in terms of dynamic load testing of the rigid struts and safety analysis of the pipes,which shows that rigid strut is low in dynamic load and the pipes and rigid strut are safe under the action of static load plus dynamic load.The rigid strut can meet the requirement for long-term safety operation.Other kind of rigid vibration-reduction equipment may also be used for vibration control of pipes.

The load deviation in constant-forced hanging bracket directly affect thermal displacement of the piping system and the performance of said hanging bracket.For this,taking the main steam pipeline of a 220 MW unit in one power plant as example,the relationship between the load deviation in constant-forced hanging bracket and the thermal displacement of piping system has been calculated and analysed.Results show that the vertical thermal displacement is increasing in the event of increasing the load deviation,while the horizontal displacement having remarkable change.In order to control the stress level in the pipeline,it is recommended to select the suitable constant-forced hanging bracket during the time of design.The constant-forced hanging brackets have already been long-term in operation or those of poor quality should be timely adjusted or replaced;the pipeline of ultrasupercritical units should use constant-forced hanging bracket with high quality and little load deviation,to ensure long-term safe and reliable operation of the pipeline and the hanging bracket.

Obvious vibration existed on medium pressure feed-water pipeline no.1 of one 210 MW CFB boiler.Through survey measurement and analysis in the field,it is believed that the main causes resulting in the pipeline vibration are as follows:low stiffness along horizontal direction of the pipeline;shortage of the effective position-limiting constraint;and abnormal state of the support-and-hanger.On the basis of mode analysis and stress calculation for the tubulature,a vibration elimination scheme has been worked out.After implementation of the said scheme,pipeline vibration is substantially reduced,the primary and secondary stress being up to standard,the thrust and moment of force applied by the pipeline onto the end equipments all are within the allowable range,vibration elimination achieving the desired result.