轴流转桨式水轮机转轮磨蚀分析
发布时间:2018-08-22 17:13
【摘要】:我国北方河流普遍含沙量较大,南方河流含沙量相对较低,但过沙量较大。运行在这些河流上的水轮机因过流部件极易受到泥沙磨损与空蚀的联合作用,产生非常严重的磨蚀,从而大幅度降低了水轮机的水力性能,且在很大程度上威胁着水轮机运行的安全稳定性。为研究含沙工况下水轮机的磨蚀性能,本文首先对轴流转桨式水轮机磨蚀机理进行分析探讨,结合电站增容改造中对转轮室处理的实际案例,分析了含沙水流对轴流转桨式水轮机转轮的磨蚀影响。采用超音速火焰喷涂方法,制备纳米WC-10Co-4Cr涂层,并在料桨磨粒磨蚀机上试验其抗磨蚀性能。本文主要研究内容如下:(1)对轴流转桨式水轮机磨蚀机理的分析及探讨,从合理运行、减少过机含沙量、优化轴流转桨式水轮机抗磨蚀涂层处理技术等方法进行综合分析。(2)通过试验的手段,对比分析纳米WC-10Co-4Cr涂层与Cr_3C_2-Ni Cr涂层的抗磨蚀效果,并研究不同含量、不同粒径泥沙对磨蚀影响。试验研究表明,纳米WC-10Co-4Cr涂层抗磨蚀效果比Cr_3C_2-NiCr涂层好。试件磨蚀失重量与时间的关系可以分为三个过程:潜伏期、加速期和稳定期。从本试验来看,水中泥沙粒径越大,对磨蚀影响就越大;泥沙浓度越大,磨蚀现象就会越严重。
[Abstract]:Generally speaking, the sediment content of the northern rivers in China is higher than that of the southern rivers, but the amount of sediment passing through the rivers is relatively lower than that of the rivers in the south. The turbine running on these rivers is easy to be affected by the combined action of sediment wear and cavitation erosion because of the excessive flow parts, which results in very serious erosion, which greatly reduces the hydraulic performance of the turbine. To a large extent, it threatens the safety and stability of turbine operation. In order to study the erosion performance of hydraulic turbines under the condition of sand, this paper first analyzes and discusses the erosion mechanism of axial flow propeller turbines, and combines with the actual cases of the treatment of runner chambers in the retrofitting of power stations. The effect of sand-bearing flow on the erosion of axial flow propeller turbine runner is analyzed. Nano-sized WC-10Co-4Cr coatings were prepared by supersonic flame spraying, and their wear resistance was tested on the abrasive grinding machine. The main contents of this paper are as follows: (1) the analysis and discussion of the erosion mechanism of the shaft flow propeller turbine, in order to reduce the sediment content in the turbine, The anti-wear coating technology of axial flow turbine was optimized. (2) by means of experiment, the wear resistance of nano-sized WC-10Co-4Cr coating and Cr_3C_2-Ni Cr coating were compared and analyzed, and the different contents of the coating were studied. The effect of different particle size sediment on erosion. The results show that the wear resistance of nano WC-10Co-4Cr coating is better than that of Cr_3C_2-NiCr coating. The relationship between abrasion weight loss and time can be divided into three processes: incubation period, acceleration period and stable period. According to this experiment, the larger the sediment particle size in the water, the greater the effect on erosion, and the more the sediment concentration, the more serious the erosion phenomenon will be.
【学位授予单位】:南昌工程学院
【学位级别】:硕士
【学位授予年份】:2017
【分类号】:TK733.5
[Abstract]:Generally speaking, the sediment content of the northern rivers in China is higher than that of the southern rivers, but the amount of sediment passing through the rivers is relatively lower than that of the rivers in the south. The turbine running on these rivers is easy to be affected by the combined action of sediment wear and cavitation erosion because of the excessive flow parts, which results in very serious erosion, which greatly reduces the hydraulic performance of the turbine. To a large extent, it threatens the safety and stability of turbine operation. In order to study the erosion performance of hydraulic turbines under the condition of sand, this paper first analyzes and discusses the erosion mechanism of axial flow propeller turbines, and combines with the actual cases of the treatment of runner chambers in the retrofitting of power stations. The effect of sand-bearing flow on the erosion of axial flow propeller turbine runner is analyzed. Nano-sized WC-10Co-4Cr coatings were prepared by supersonic flame spraying, and their wear resistance was tested on the abrasive grinding machine. The main contents of this paper are as follows: (1) the analysis and discussion of the erosion mechanism of the shaft flow propeller turbine, in order to reduce the sediment content in the turbine, The anti-wear coating technology of axial flow turbine was optimized. (2) by means of experiment, the wear resistance of nano-sized WC-10Co-4Cr coating and Cr_3C_2-Ni Cr coating were compared and analyzed, and the different contents of the coating were studied. The effect of different particle size sediment on erosion. The results show that the wear resistance of nano WC-10Co-4Cr coating is better than that of Cr_3C_2-NiCr coating. The relationship between abrasion weight loss and time can be divided into three processes: incubation period, acceleration period and stable period. According to this experiment, the larger the sediment particle size in the water, the greater the effect on erosion, and the more the sediment concentration, the more serious the erosion phenomenon will be.
【学位授予单位】:南昌工程学院
【学位级别】:硕士
【学位授予年份】:2017
【分类号】:TK733.5
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