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题名	冷凝器工况对定子自循环蒸发冷却系统影响及定子线棒截面温度分布的研究; 冷凝器工况对定子自循环蒸发冷却系统影响及定子线棒截面温度分布的研究
作者	1刘斐辉,电工研究所
学位类别	博士
答辩日期	2008-06-06
授予单位	中国科学院电工研究所
导师	1顾国彪,电工研究所
关键词	蒸发冷却技术 水轮发电机 两相流,冷凝器 定子温度场 evaprative cooling technology hydro-generator two-phase flow condensor stator bar temperature distribution
其他题名	冷凝器工况对定子自循环蒸发冷却系统影响及定子线棒截面温度分布的研究
中文摘要	经过20年的工业应用实践证明，自循环蒸发冷却技术使用高绝缘的冷却介质在继承水内冷优点的同时避免了水内冷的弊端，将成为大容量和超大容量水轮发电机的主流冷却方式。 为了对自循环系统有更深的认识，本文进行了冷凝器运行压力对循环系统影响及冷凝器断水实验的研究。与此同时，由于冷凝器是循环系统中的重要部件，决定了蒸发冷却系统总体的压力水平和温度水平。为了更加全面的评价蒸发冷却自循环系统，把冷凝器的传热方程引入了循环系统后提出了理论计算方法，通过计算高、低欠热沸腾起始点、沸腾起始点和已有通用关系式划分流型后，选用Friedel方法计算两相段摩擦阻力，分段计算压降使得更为准确的确定空心导线的沿程压力。在空心导线内冷却介质与壁面换热计算中，选取了相关流型适用的对流换热系数的方法，减小了空心导线沿程壁温的仿真计算误差。由冷凝器的传热方程出发，求解的循环流量和冷凝器入口处冷却介质干度，避免了选用的两相摩擦压降公式造成的影响，更直接的反映了循环参数，并通过与实验数据的对比，验证了思路的正确；根据非稳定流动能量守恒方程计算了断水后冷凝器的管外壁温与壳外壁温、冷凝器断水压力随时间的变化关系，与实验数据比较后说明对参数的处理是合理的。 为使蒸发冷却技术进一步得到推广，本文对大型水轮发电机采用此技术后的定子温度分布进行了分析计算。通过与空冷方式下的温度分布比较，显示蒸发冷却技术的优越性，对比了计及与不计股线绝缘的温度场分布，并对空心导线内冷却介质发生流动不畅时及空心实心组合中空心导线位置不同时定子线棒截面的温度分布进行了分析。 Having been put into industrial operation for more than 20 years, The technology of the closed-loop-self-circulating evaporative cooling inherits all advantages of the water-cooled method while overcomes the inferior position of the block and leak, which will be the main cooled method on Large and super generators,. In order to have further knowledge about the characteristics of the CLSC evaporative cooling system, The theoretic model experiment of the effect of the condenser’s pressure on the CLSC evaporative system’s parameters by modulating the water flux or the electrical current and of the condenser’s pressure along with the shut water’s time. Because the condenser is the important composing of the system, which determined the level of the pressure and temperature of the total evaporative cooling system, It is necessary to consider the over-all heat transfer equation of the condenser on the general theoretical calculative method for the CLSC system in order to across-the-board estimate. ONB and FDB were calculated; The Friedel method was selected to compute the two-phase frictional resistance，By means of the subsection ,The lengthwise pressure of hollow conductor was more accurately computed, for the heat exchange between the coolant and the conductor wall, the correlative coefficients of convection heat transfer were calculated to the different flow patterns which make the computing the result of the temperature distribution more accurate. From the point of view of the over-all heat transfer equation, the circular flux and the dryness of the coolant on the condenser inlet were computed by avoiding the effect of the two-phase friction formula. The contrast computation and experiment proved the right of consideration. According to the unsteady flow conservation of energy, the outer wall temperature of the pipe and the shell of the condenser and the pressure along with the shut water time were calculated. The contrast with the experiment proved the exactness of the presupposition. In order to improve the applied degree of the technology, it was necessary to do the further research about the evaporative cooling effect on the stator temperature. It could prove the good qualities by contrast to the temperature distribution on the condition of the air cooled. The temperature distributions were computed on considering the thickness of the strand insulation or not and the analysis was done about the temperature distribution of the stator bar in the evaporative cooling system of the hydro-generator on flow blocked and the effect on the different conductor’s collocation on the temperature distribution of the stator bar in the evaporative cooling system.
语种	中文
公开日期	2010-10-18
页码	125
分类号	TM3;TM5
内容类型	学位论文
源URL	[http://ir.iee.ac.cn/handle/311042/6754]
专题	电工研究所_其他部门_其他部门_博士学位论文
推荐引用方式 GB/T 7714	1刘斐辉,电工研究所. 冷凝器工况对定子自循环蒸发冷却系统影响及定子线棒截面温度分布的研究, 冷凝器工况对定子自循环蒸发冷却系统影响及定子线棒截面温度分布的研究[D]. 中国科学院电工研究所. 2008.

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