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对机组在夏季纯凝工况运行时凝汽器补水方式改造的可行性和经济性进行分析,以等效焓降原理计算由此而带来的经济效益,改造后,补水的除盐水达到初步除氧效果,增强了除氧器的运行稳定性,而且使机组后汽缸排汽起到冷却、凝结作用,提高了机组运行的真空度,提高了机组运行的经济性。 相似文献
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针对某200MW机组除氧器给水含氧量严重超标、填料散失、雾化喷嘴弹簧失效等问题,对除氧器结构进行了改进,并采取了一系列措施对除氧器进行了改造,提高了系统的经济性和运行安全性。 相似文献
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一、概述 由于电厂火电机组存在汽水损失,为维持其连续运行,必须经常向热力系统补充化学水。补水方式有两种:一是按传统方法通过除氧器补入热力系统;一是通过凝汽器补入热力系统。后一种补水方式,可以使补水在凝汽器内实现初步除氧,降低对低压加热设备的氧腐蚀程度。若补水以喷雾状态进入 相似文献
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针对一2×600 MW直接空冷机组夏季高温时段背压高、煤耗高的现状,借鉴直接空冷机组的改造经验,将中水作为尖峰系统的补水,达到了降低机组运行背压、提高机组夏季发电负荷、降低煤耗的目的,同时评估了改造后机组的经济效益。 相似文献
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目前我国部分热电厂拆除原有的凝汽式或抽凝式汽轮机,采用背压式汽轮机,以期提高机组运行效率及经济性。背压机组因没有低压回热加热系统,只能采用高压排汽在除氧器中加热补水,造成的热损失较大。因而考虑设计一种新型背压机,它是利用在机内做完功后的低压回热抽汽及排汽来加热补水。方案是把原有的抽凝式、凝汽式机组改造为既可向外部供气,又可用低压回热抽汽及排汽加热补水的机组。因凝汽器被改造为第一级补水加热器,没有冷端放热损失,成为了一种新型背压机,它不仅能节省大量投资,而且能降低热耗,提高机组能效,是一种既可行又经济的改造方法。 相似文献
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基于等效焓降法定量分析了两种补水方式的热经济性差异,通过实例计算结果得出,采用补充水补入凝汽器的方式,可以明显提高机组经济性。对补充水补入凝汽器的补水量和补水进入方式问题进行讨论,补充水应以雾化状态喷入凝汽器的喉部,形成一个均匀分布的雾化带,使其合理利用排气余热,降低冷源损失,并利用低品位抽汽加热,减少高品位抽汽量,提高回热经济性,同时可加快气体的逸出,为除氧创造有利条件。 相似文献
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This article provides a comprehensive review of the spray combustion of fast pyrolysis bio-oil (FPBO, also called bio-oil, pyrolysis oil or pyrolysis liquid biofuel), which is widely regarded as one of the most economically feasible renewable resources to facilitate the replacement of fossil oils. The utilization of FPBO as a fuel is challenging due to its unique atomization and combustion characteristics but it is important given the need to develop a more sustainable energy infrastructure. Significant efforts have been made in utilizing FPBO as a practical alternative fuel and the first FPBO facilities for heat and/or power generation have been brought online in recent years. FPBO-fueled burners, boilers, and furnaces are ready from a technical perspective for large-scale industrial use, and even small-scale systems show excellent flame stability, low emissions, and minimal requirements for secondary fuel usage. FPBO applications in gas turbine and compression-ignition engines are technically more challenging, currently having had only limited successes in larger-scale units and for short time intervals in smaller ones. With recent research and technological advances, however, FPBO use in small-scale combustion engines appears to be technically feasible. In the literature, extensive research efforts have been dedicated to this topic either as a fuel itself or its utilization for practical applications. Nonetheless, inadequate considerations have been given to the critical role of FPBO atomization and its subsequent fuel/air mixing, which in turn controls the combustion efficiency and emission characteristics of a system. Understanding the spray combustion properties of FPBO is especially important because of the fuel's unfavorable properties compared to fossil oils including low energy density, high viscosity, high water content, containing suspended solid particulates and non-volatile residue, chemical instability, and an incompatibility with conventional fossil oils. The information presented herein, therefore, focuses on understanding the challenges and constraints that are unique to FPBO applications, along with proposing several strategies to properly atomize and combust this fuel in order to enhance combustion efficiency and reduce pollutant emissions in practical systems. Although substantial progress has been made in understanding the FPBO spray combustion as revealed by this review, better standardization of FPBO properties, more efficient techniques for optimizing atomization and combustion for different applications, and more studies to understand the long-term reliability of devices running on FPBO are needed. 相似文献
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风力发电具有波动性、间歇性和随机性的特点,风力发电的并网给电力系统的安全运行带来了严峻挑战,因此,实现风电场风速的预测具有重要意义。支持向量机是发展比较好的一种常用的风速预测方法,但是由于其输入特征对预测的精度影响比较大,所以特征的选择一直是人们所关注的问题。文章提出采用相空间重构理论对风电场风速进行预测,并通过与使用自然特征作为输入特征的预测方法作比较,验证了基于相空间重构的支持向量机的预测方法的优越性。 相似文献
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Praveen K. Cheekatamarla Caine M. FinnertyYanhai Du Juan JiangJian Dong P.G. DewaldC.R. Robinson 《Journal of power sources》2009
Solid oxide fuel cells (SOFCs) constitute an attractive power-generation technology that converts chemical energy directly into electricity while causing little pollution. NanoDynamics Energy (NDE) Inc. has developed micro-tubular SOFC-based portable power generation systems that run on both gaseous and liquid fuels. In this paper, we present our next generation solid oxide fuel cells that exhibit total efficiencies in excess of 60% running on hydrogen fuel and 40+% running on readily available gaseous hydrocarbon fuels such as propane, butane etc. The advanced fuel cell design enables power generation at very high power densities and efficiencies (lower heating value-based) while reforming different hydrocarbon fuels directly inside the tubular SOFC without the aid of fuel pre-processing/reforming. The integrated catalytic layered SOFC demonstrated stable performance for >1000 h at high efficiency while running on propane fuel at sub-stoichiometric oxygen-to-fuel ratios. This technology will facilitate the introduction of highly efficient, reliable, fuel flexible, and lightweight portable power generation systems. 相似文献
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地热资源是一种清洁无污染、可再生的新型能源,对于发展低碳经济、实现可持续发展具有积极的作用.目前地热发电技术主要包括干蒸汽发电、扩容式蒸汽发电、双工质循环发电和卡琳娜循环发电等.其中干蒸汽发电系统工艺简单,技术成熟,安全可靠,循环效率可达20%以上,是高温地热田发电的主要形式;扩容式发电技术已在地热发电领域得到广泛应用,尤其是中高温地热田,二级扩容系统循环效率约为15%~20%;针对中低温地热资源,双工质循环发电技术是较为适用的,它由地热水系统和低沸点介质系统组成,循环效率较扩容式蒸汽发电技术可提高20%~30%;卡琳娜循环在低温地热资源应用领域中有其独特的优越性,通过调整氨和水的比例,可以适应低温地热水的发电特性,卡琳娜循环发电技术的循环效率比朗肯循环的效率高20%~50%.在低温地热资源的开发利用过程中,双工质循环和卡琳娜循环技术具有广阔的发展前景.作为一种新型地热资源,干热岩具有很高的开发利用价值.新型的联合循环发电技术是地热发电技术的发展方向.在浅层地热能得到大规模开发后,中深层地热资源和干热岩资源将成为地热发电技术新的资源,我国应注重中深层地热资源和干热岩资源的开发. 相似文献
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本文根据港口供电特点,分析了港口供电中高次谐波的产生,以及对运行中电容器的危害,提出了消除高次谐波对运行中电容器影响的措施。 相似文献
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本文着重介绍了镇海联合发电有限责任公司300MV燃气-蒸汽联合循环机组余热锅炉烟气挡板改造,以及基于北京ABB贝利公司Conductor NT系统建立的烟气挡板程序控制系统方案的组态和投运情况。在锅炉DCS改造中把烟气挡板程控系统纳入了Conductor NT,通过改造降低了故障率,提高了烟气挡板控制系统的可靠性。 相似文献