【作者】 陈俊；

【导师】 郭常宁； 孙国忠；

【作者基本信息】 上海交通大学 ， 机械工程， 2015， 硕士

【摘要】 地坑过滤器是核电站安全系统中的重要设备,事故工况下过滤安全壳喷淋系统和安全注入系统水中的杂质,保证系统的正常运行。1992年瑞典的Barseb?ck Kraft AB沸水堆核电厂发生了地坑过滤器堵塞,造成了一台泵发生气蚀,安全壳喷淋系统无法使用。事件发生后,地坑过滤器的性能成为一个新的核安全研究热点。各核电先进国家相继开展了新型地坑过滤器的研发工作。新型地坑过滤器由框架和过滤模块组成,过滤模块安装在框架上,若干个框架串联成一排组成整个地坑过滤器。新型地坑过滤器在流量和过滤精度上需要满足过滤系统的要求,同时本身的压降应足够小而不会使泵发生汽蚀,即压降要求。新型地坑过滤器尺寸和流量较大,压降试验操作性和经济性较差。利用相似理论建立过滤器相似模型,将地坑过滤器的尺寸进行一定比例的缩小,同时对流量等参数进行对应的缩小,保证相似模型和原型满足几何相似、运动相似和动力相似。基于变态相似理论,将相似模型设计为变态相似模型,三维几何尺寸不按相同比例缩小,仅缩小地坑过滤器长度尺寸,保留宽度、高度和过滤孔径等尺寸。考虑到压降问题将地坑过滤器由多个相同的框架串联组装而成,将单个框架作为变态模型。根据方程分析法,保证变态模型和原型相似的前提下,计算出流量、碎片量等参数的缩小值。事实证明,该变态模型能获得较好的相似率,即能真实的反映原型工况,又使试验有较好的操作性和经济性。变态相似模型建立后,根据相似率对模型进行试验。试验参数和原型工况参数的相似系数满足变态模型和原型的变态相似关系。根据原型的不同运行工况(包括全载荷试验、薄床效应和化学效应)和过滤模块类型(三层过滤模块、双层过滤模块和单层过滤模块),进行了七个不同工况的试验,逐一验证不同工况和不同过滤模块下地坑过滤器的压降性能和可靠性。试验结果验证了三层过滤模块对薄床效应会产生较低的压降,对全载荷碎片情况会产生较高压降。双层过滤模块对薄床效应会产生相对于三层过滤模块较高的压降,对全载荷碎片情况会产生较低的压降。单层过滤模块因过滤面积过小而产生压降较大。根据模型和原型的相似比,通过相似计算获得原型实际工况(120℃)的压降。更多还原

【Abstract】 Sump Strainer is key equipment of Nuclear Power Plant safety system, filter the debris of containment spray system and safety injection system and make sure normal operation of systems. In 1992, Barseb?ck Kraft AB Nuclear Power Plant came up a sump strainer blockage accident, caused a pump cavitation, and Reactor Spay System cannot be used. The accident made the function of Sump Strainer a new research hotspot for nuclear safety study. All of the advanced nuclear countries start to develop strategy research and design improvements.New type of sump strainer is consisted of filter frame and filter module. The filter modules are installed on the filter frame and several filter frame connection in series to a sump strainer. The new type of sump strainer should meet the requirement of flow rate and filter fineness and also to make sure the head loss of sump strainer is low enough to not make the pump cavitation which is head loss requirement.Sump strainer dimension and flow rate are very large, so the prototype test cannot be performed for operational and economical reasons. By using of similarity theory, the test model’s dimension is reduced and test parameters are reduced to confirm the model is geometry, motion and dynamics similarity with prototype. Based on distorted theory which the similarity is different for the three-dimensional physical dimension, a sump strainer distorted model is developed for sump strainer head loss test, it only reduced the length of prototype and keep the width, height and filter hole. Consider of sump strainer is consist of several same filter frames. A filter frame is chosen to be the distorted model. Using equation analysis method, the reduced value of flow rate, debris quantity can be calculated. The distorted model is approved to similar with prototype by similarity calculation.and is good at reductive property, economics and operability.According to test parameter and distorted model’s requirement, model test is carried out. Then according to sump strainer different work condition(full load condition and thin bed condition) and the different type of filter module(triple, double and single), a series of head loss tests are performed to verify the head loss of sump strainer, totally 7 different tests for different work condition and different filter module.Head loss test results verify that triple filter module will generate low head loss at thin bed condition and high head loss at full load condition, double filter module will generate high head loss at thin bed condition and low head loss at full load condition compare to triple filter module, single filter module will generate high head loss as small filter area. According to similarity factor of distorted model and prototype, the prototype’s head loss at work condition(120℃) can be calculated.更多还原