共查询到20条相似文献,搜索用时 343 毫秒
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本研究建立了超临界机组及其控制系统的数学模型,编制了机组变工况特性计算软件,研究了一次调频对超临界机组汽轮机动态热力特性影响的规律。采用集总参数和分布参数相结合的方法建立了机组的动态数学模型,对不同运行工况下机组的静态和动态特性进行了分析,得到了机组不同运行工况下负荷扰动及调节系统参数对机组流量、调节级后压力和温度、再热器后温度影响的规律。结果表明,随着负荷扰动的增大,无论机组定压运行还是滑压运行,各物理量动态过程中的百分比超调量不变,机组高、中压各级温度的变化可以忽略。机组滑压运行时,在维持锅炉出口温度不变的条件下,随着流量压力环节时间常数和功率流量环节时间常数的增加,高压调节级后的温度变化约1.5℃,再热器后温度变化约0.2℃。因此,一次调频对超临界机组不同运行工况下热力参数动态特性的影响非常小,不会影响机组运行的安全性和稳定性。 相似文献
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国家计委、国家经贸委、电力工业部、建设部于1998年2月17日联合发布的《关于发展热电联产的若干规定》第八条明确规定,“发展热电联产应优先安排现有中、小型凝汽机组改造为供热机组”.目前我国许多中小电厂安装有为数不少的中、小型凝汽式汽轮发电机组.这些机组由于煤耗高、热效率低,有的已停止运行,有的即将停止运行.因此,将其改造成供热机组,实行热电联产,是改造中小电厂的唯一 相似文献
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高压加热器的运行对机组的热经济性具有重要影响.以300 MW凝汽式机组的热力系统为例,结合高加的端差、抽汽压力损失和散热损失3个方面,得出了高加运行与机组热经济性的具体关系和影响机组热经济性的强度系数,并绘制出了强度系数、得出煤耗率与机组负荷的关系曲线.得到了机组的运行中需要重点监测的参数和系统的改造方案,为机组的最优运行和改造工作提供了理论基础. 相似文献
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针对目前大容量高参数机组所具有的低压和中压凝结水系统在除氧器滑压运行的特点进行了管路特性的确定,并通过低压系统中工频凝结泵与变频凝升泵串联运行,以及中压系统中凝结泵变频运行的调节特性分析,给出了为保证系统设备所需最低压力和水泵最低转速的限制下两种系统更加合理的运行方式;以典型的300MW亚临界同容量机组为例进行能耗比较,为现行的低压凝结水系统是否有必要进行节能改造提供了可参考的理论依据. 相似文献
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采用计算流体力学(Computational Fluid Dynamics,简称CFD)开展了汽轮机高压缸整缸的内部流场计算和低压缸末三级的变工况分析。还采用CFD分析了某空冷机组低压排汽缸流场,比较了模型排汽缸的试验和数值计算结果,又分析实际排汽缸流场的CFD计算结果,提出并验证了一个提高其静压恢复能力的优化改进措施。在总结上述成功实践的基础上,展望了基于CFD等先进技术在汽轮机行业建立新技术体系的前景。 相似文献
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Solid oxide fuel cell(SOFC) vehicles are considered to have broad prospects for development, and the high operating temperature of SOFC results in great potential for waste-heat recovery. Many concepts for utilizing waste heat of SOFC have been suggested and studied, and most of them directly couple an SOFC to a gas turbine, which require the SOFC to operate at an elevated pressure and make the system less flexible and thus harder to operate. In recent years, with the development of turbine and heat exchanger technology, the supercritical carbon dioxide(S-CO_2) power cycle has raised widespread attractions for the waste recovery. This study explores the potential of S-CO_2 Brayton cycle to realize waste-heat recovery for an SOFC vehicle. The SOFC can operate at atmospheric pressure, and the hybrid system is easier to operate than the directly coupled systems. In this paper, a simple recuperated S-CO_2 Brayton cycle is proposed and the key component, radial inflow turbine is designed and focused. The flow state of the designed turbine is analyzed in detail based on computational fluid dynamics(CFD) numerical simulation. Five cases with different impeller tip clearances are numerically simulated to study its influence on the turbine performance. In addition, off-design performance analysis of the radial inflow turbine is conducted considering the temperature fluctuation of SOFC in practical applications. 相似文献
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冷却空气量是影响燃气轮机性能的关键因素,透平冷却技术研究的重点方向是以最少的冷却空气量来达到最好的冷却效果,才能使燃气轮机性能达到先进水平.对市场上具有代表性的某些型号的燃气轮机冷却空气量进行了推算,并对300 MW等级燃气轮机在不同透平初温、不同冷却空气量下的性能进行了计算,对透平初温、冷却空气量对机组循环性能的影响进行了定性分析. 相似文献
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A 2 MW gas turbine engine has been developed for the distributed power market.This engine features a 7:1 pressure ratio radial inflow turbine.In this paper,influences of various geometry features are investigated including turbine tip and backface clearances.In addition to the clearances,the effects of the inducer deep scallop and exducer rounded trailing edge are investigated.Finally,geometric features associated with a split rotor(separate inducer and exducer)are studied.These geometry features are investigated numerically using CFD.Part of the numerical results is also compared to experimental data acquired during engine test to validate the CFD results. 相似文献