燃气轮机发电机组黑启动方案探讨

不同电厂的黑启动方案由于机型和系统接线的差异而千差万别,但黑启动过程设计中的关键因素如黑启动负荷加载顺序、黑启动柴油发电机组选型、死母线合闸、孤岛运行控制等却有着原理一致性和可归纳性。基于9E机组的黑启动成功案例,阐述燃气轮机电厂黑启动必须考虑的重要负荷顺序以及黑启动柴油机的选型计算过程。对死母线合闸、孤岛运行控制等黑启动方案中关键步骤进行原理描述和经验总结,并介绍了优化方法和现场经验及需要注意的特殊环节,为今后黑启动方案设计提供参考和借鉴。     

水电站黑启动的研究与实践

当电网出现全部或部分故障停运后,系统全部停电,可以通过黑启动方案,实现整个电网的恢复。由于电厂运行方式不同以及机型和系统接线的差异,不同电厂的黑启动方案各有区别。介绍了黑启动的相关概念,并给出了重庆某水电厂的黑启动过程的具体实践过程。     

9FA燃气轮机作为电网"黑启动"电源点的探讨

S109FA联合循环组在启动、加负荷的快速性上基本能满足电网“黑启动”的要求;当整个电网因故障停运后,9FA燃气轮机作为“黑启动”电源点的启动,需要启动电源和辅助蒸汽,用配备一套小功率的燃气轮机联合循环机组可以解决。即:用9FA燃气轮机配备的自动柴油发电机来启动小功率的燃气轮机联合循环机组,然后再逐渐完成“黑启动”,向外恢复供电。还分析了9FA燃机在“黑启动”时可能遇到的问题及对策。     

燃气轮机作为自启动电源的电网黑启动案例

基于系统安全稳定运行的需要,以燃气轮机发电机组作为自启动电源成功的完成电网黑启动试验.经过空网充电、加负荷、起动火电机组、甩负荷等一系列实战演练,证明燃气轮机发电机组是最佳的黑启动电源.     

新建火电厂启动锅炉的无火热备用

新建火电厂启动锅炉的无火热备用胜利发电厂尹笑天１问题的提出新建火电厂由于不具备扩建电厂原有可靠的外部蒸汽汽源的条件，在工程立项中，必须配套设计、安装相应容量和数量的启动炉，作为机组试运行期间乃至投产后机组启动时所必须的辅助用汽汽源（不直接发电）。当机...     

一种适用于微电网黑启动的改进微源电压控制策略

孤岛运行的微电网故障后,系统的重新恢复供电关系到微网能否安全稳定运行。文章根据光储微电网中各微源的特性以及黑启动微源的选取原则,选取合适的黑启动电源。为了让黑启动电源在系统恢复初期更好地为微网交流母线提供电压频率支撑,提出一种适用于微电网黑启动的微源电压控制策略,通过改进微源下垂特性,实现微电源输出电压从零开始上升建立电压的过程,确保配电变压器的零起升压功能。最后,在PSCAD仿真平台上搭建了相应模型进行仿真,结果表明,所提电压控制策略有效支撑了微网孤岛运行的电压频率,提高了微网的安全稳定性。     

含分布式电源配电网的黑启动运行特性研究

对于电力系统局部失电或大面积失电,利用分布式电源恢复供电的黑启动方案具有重要意义。文中在分布式电源配电网建模的基础上,结合含分布式电源的配电网自身特点,以配有储能装置、具有电压/频率控制能力的分布式电源作为黑启动电源,分析其黑启动运行特性,给出含分布式电源黑启动的优化组合方案。最后,仿真验证了优化配置方案的有效性,为配电网实现黑启动预案提供必要的理论基础     

基于联络矩阵法的黑启动分区与机组启动顺序选择方案

针对黑启动过程中合理分区的重要性,考虑黑启动过程中线路恢复成功率与机组启动成功率,提出了机组恢复期望功率这一黑启动恢复指标。首先利用所提指标结合线路恢复时间建立节点分区判定目标函数,初步确定各待恢复节点所属分区;然后利用分区子系统期望恢复功率与分区网架结构形成时间建立新的分区目标函数,利用改进的模拟退火法求解该目标函数以实现黑启动分区的全局优化;最后得出了待恢复机组所属分区以及各分区内机组恢复顺序,并找到了所有待恢复机组的最优黑启动路径。     

50 MW水煤浆机组电网黑启动实践和改进

＂黑启动＂是电网机组启动的一种特殊而重要的方式.介绍了50 MW水煤浆机组首次电网黑启动实践,对水煤浆机组通过黑启动演习暴露出来的问题提出解决对策,相关问题的妥当解决可以使水煤浆机组成为真正意义的实现黑启动机组.     

启动锅炉炉底推动保压技术

为节省启动锅炉热备用运行成本,设想一种新型炉底推动技术替代现有点火方式,并根据热平衡理论推算出该技术所消耗蒸汽量,从多角度论证该技术方案可行。     

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.     

节能环保技术措施在火电厂中的应用

现如今,环境保护、生态节能得到了社会广泛的重视与关注,如何减少污染、实现生态节能成为重要研究课题。火电厂作为大气排放主要企业,节能环保成为火电厂经营发展当务之急,应用节能环保技术措施是对火电厂的根本要求,也是在激烈的竞争中实现长存的有效路径。针对节能环保技术在火电厂应用过程中存在的问题,给出优化措施,旨在提升火电厂整体效益。     

Transient thermal modelling of heat recovery steam generators in combined cycle power plants

Heat recovery steam generator (HRSG) is a major component of a combined cycle power plant (CCPP). This equipment is particularly subject to severe thermal stress especially during cold start‐up period. Hence, it is important to predict the operational parameters of HRSGs such as temperature of steam, water, hot gas and tube metal of heating elements as well as pressure change in drums during transient and steady‐state operation. These parameters may be used for estimating thermal and mechanical stresses which are important in HRSG design and operation. In this paper, the results of a developed thermal model for predicting the working conditions of HRSG elements during transient and steady‐state operations are reported. The model is capable of analysing arbitrary number of pressure levels and any number of elements such as superheater, evaporator, economizer, deaerator, desuperheater, reheater, as well as duct burners. To assess the correct performance of the developed model two kinds of data verification were performed. In the first kind of data verification, the program output was compared with the measured data collected from a cold start‐up of an HRSG at Tehran CCPP. The variations of gas, water/steam and metal temperatures at various sections of HRSG, and pressure in drums were among the studied parameters. Mean differences of about 3.8% for temperature and about 9.2% for pressure were observed in this data comparison. In the second kind of data verification, the steady‐state numerical output of the model was checked with the output of the well‐known commercial software. An average difference of about 1.5% was found between the two latter groups of data. Copyright © 2007 John Wiley & Sons, Ltd.     

Performance enhancement in coal‐fired thermal power plants. Part III: auxiliary power

Auxiliary power in coal‐fired power stations accounts for 7% (500 MW units) to 12% (30 MW units) of the gross generated power at the full plant load. The minimum AP varies between 4·5 and 9·0% for the same capacity range. The excessive power due to factors such as coal quality, excessive steam flow, internal leakage/ingress in equipment, inefficient drives, distribution network losses, reduced power quality, ageing, etc., is quantified. An experimental study has shown that 85·7% of the AP in excess of the design value can be traced to coal quality and its indirect effects. The AP can be minimized even below the design value by operational optimization, overhaul of equipment and revamping. The paper discusses in detail the techniques for restoration of the AP to the designed value and further improvements. Copyright © 1999 John Wiley & Sons, Ltd.     

等离子点火技术在电厂蒸汽冲管中的应用

介绍了等离子点火技术在国华宁海发电厂4号机组锅炉蒸汽冲管中的应用情况,对冲管过程中一些参数的控制及注意点进行了探讨,可为后续工程提供借鉴.     

Maximum power cold start mode of proton exchange membrane fuel cell

Successful and fast cold start is important for proton exchange membrane (PEM) fuel cell in vehicular applications in addition to the desired maximum power in any case. In this study, the maximum power cold start mode is investigated in details and compared with other cold start modes based on a multiphase stack model. It is found that for the maximum power cold start mode, the current density is generally kept at high levels, and the performance improvement caused by the membrane hydration and temperature increment may not be observable. Therefore, before the melting point, the performance drops continuously. The maximum power cold start mode could better balance the heat generation and ice formation, leading to improved cold start survivability than that in the constant voltage and constant current modes, with a fast start-up generally guaranteed. Once the survivability can be ensured, the initial water content needs to be higher for fast cold start, suggesting that over purging should be avoided. The maximum power mode is suggested to be optimal for PEM fuel cell cold start based on the modeling results.     

Current status of Japanese thermal power plants and life assessments of high temperature steam and gas turbine components

More than 80% of prime energy is now supplied by thermal power plants in Japan since the Great East Earthquake of 2011 and more than two thirds of them were operated for over 30 years. Evaluation of the residual life of those aged plants are, therefore, required to maintain reliability and also to avoid premature retirement. Several kinds of life assessment technologies for the high temperature components of aged steam and gas turbines have already been developed and applied to actual components. Further developments for the advanced ones are now still being conducted. The current status of Japanese thermal power plants is briefly overviewed and the life assessment technologies developed for evaluating the material degradation and component damage conditions and life extension capabilities of steam and gas turbines are explained with some examples of the applications. The differences between the development concepts and the methods developed for both turbines are also explained along with those of the design specifications.     

Performance enhancement in coal fired thermal power plants. Part I: boilers

This paper presents the results of the performance enhancement study in 22 coal fired thermal power stations of capacities 30–500 MW. The efficiencies and performance indices of the equipment are evaluated which then leads to the performance evaluation route—operational optimization, simple modification of equipment or renovation. The generic problems associated with design, operation and fuel inputs is investigated and appropriate solutions are suggested to improve the boiler efficiency levels from 71–86% to 86–87% immediately and 89–90% on a long term (5–10 yr) basis. A large volume of design and operating data has been analysed and presented in the form of curve fits for computer simulation of the performance of boilers for high ash coals. Copyright © 1999 John Wiley & Sons, Ltd.