基于热—流—固耦合高温热水循环泵结构强度的研究

发布时间：2018-06-17 09:28

本文选题：热-流-固耦合 + 数值模拟　；参考：《江苏大学》2017年硕士论文

【摘要】：高温热水循环泵是冶金、石化、电力等行业中输送高温高压介质的关键设备。该设备长期运行的可靠性对于上述行业的相关工艺流程起到至关重要影响。与常规循环泵相比,高温热水循环泵输送介质温度较高,这一方面使得泵的过流部件受热变形而产生热应力,另一方面影响了转子运行的稳定性,导致高温热水循环泵的运行可靠性较差。在江苏省六大人才高峰项目(2014-ZBZZ-016)和扬州市自然科学基金项目(No.YZ2016116)的资助下,本文采用数值计算对高温热水循环泵的泵体及转子结构强度进行研究:探讨了高温工况下,蜗壳结构参数对泵内流场、温度场以及泵体结构强度的影响规律;分析了蜗壳结构参数对转子变形量及等效应力的影响;讨论了不同介质温度时,温度和压力载荷影响下的泵体结构强度。主要研究工作如下:1.整理归纳了热-流-固耦合、模态分析及疲劳分析的基本理论,并基于之前学者的研究成果确定了本文基于热-流-固耦合作用下分析不同结构参数对泵体及转子系统结构强度影响规律的研究内容。2.利用Fluent软件对三种不同温度工况下的流场进行数值计算,并将常温下泵的性能曲线与实验结果进行对比,验证了本文采用数值模拟方法的准确性。3.基于Workbench平台,对泵体、叶轮、泵轴等施加温度和压力载荷,定义对应的边界条件,进行稳态热分析、静力学分析以及模态分析,对比不同结构参数下的数值计算结果,掌握了蜗壳的基圆直径、隔舌安放角、进口宽度以及出口的位置对泵体及转子结构强度的影响规律,得到以下结论:(1)基圆直径D3=216mm时的模型泵泵体的最大等效应力最小,而泵轴的等效应力值却为最大;隔舌安放角对泵内流场的影响较小,但是影响了热水循环泵运行的可靠性。(2)泵体变形和等效应力的最大值随着蜗室进口宽度的增大而逐渐减小,而泵轴和叶轮的等效应力值在b3=18mm时最小;蜗壳采用中心排出布置方式,泵体的变形量大于切向排出的泵体,此时,叶轮、泵轴和叶轮螺母的等效应力值也明显较大。(3)随着输送介质温度的升高,泵体壁面附近流体的温度梯度显著增加,泵体沿其厚度方向的温度变化更加明显;介质温度升高,与压力载荷和重力的作用相比,温度载荷对泵体的最大等效应力的影响愈加明显。
[Abstract]:High-temperature hot water circulating pump is the key equipment for conveying high temperature and high pressure medium in metallurgical, petrochemical and power industries. The reliability of the long-term operation of the equipment plays a vital role in the related processes of the above industries. Compared with the conventional circulating pump, the high temperature hot water circulating pump conveys the medium at a higher temperature. On the one hand, it causes the thermal stress in the over-flowing parts of the pump, and on the other hand, it affects the stability of the rotor. The operation reliability of high temperature hot water circulation pump is poor. Supported by six talents peak projects in Jiangsu Province 2014-ZBZZ-016) and Yangzhou Natural Science Foundation Project No. YZ2016116), the structural strength of high temperature hot water circulating pump is studied by numerical calculation. The influence of volute structure parameters on the flow field, temperature field and the structure strength of pump body is studied, and the influence of volute structure parameters on rotor deformation and equivalent stress is analyzed. The structural strength of the pump body under the influence of temperature and pressure load. The main research work is as follows: 1. The basic theories of thermal-fluid-solid coupling, modal analysis and fatigue analysis are summarized. Based on the previous research results, the research contents of this paper based on thermal-fluid-solid coupling to analyze the influence of different structural parameters on the structural strength of pump body and rotor system are determined. The flow field under three different temperature conditions is numerically calculated by fluent software, and the performance curve of the pump at room temperature is compared with the experimental results, which verifies the accuracy of the numerical simulation method in this paper. Based on the Workbench platform, applying temperature and pressure load to pump body, impeller, pump shaft and so on, defining corresponding boundary conditions, carrying on steady state thermal analysis, statics analysis and modal analysis, comparing the numerical calculation results under different structural parameters. The influences of the diameter of the base circle, the angle of setting the tongue, the width of the inlet and the position of the outlet on the structural strength of the pump body and rotor are mastered. The following conclusions are obtained: the maximum equivalent stress of the model pump body is the minimum when the diameter of the base circle is 216mm, and the maximum equivalent stress of the model pump body is minimum when the diameter of the base circle is 216mm. But the equal effect force value of pump shaft is the biggest, the angle of setting the tongue has little influence on the flow field in the pump, but the maximum deformation and equivalent stress of the pump body decrease with the increase of the inlet width of the cochlear chamber, but the reliability of the hot water circulation pump is affected by the operating reliability of the pump, and the maximum of the equivalent stress decreases with the increase of the inlet width of the cochlear chamber. The equal effect force value of pump shaft and impeller is minimum in b3=18mm, the volute is arranged in center, the deformation of pump body is larger than that of tangential discharge pump body, at this time, the impeller, The equal-effect force value of pump shaft and impeller nut is also obviously larger. 3) with the increase of the temperature of the conveying medium, the temperature gradient of the fluid near the wall of the pump body increases significantly, and the temperature of the pump body along the direction of its thickness is more obvious, and the temperature of the medium increases. Compared with the effect of pressure and gravity, the effect of temperature load on the maximum equivalent stress of pump body is more obvious.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH38

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