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热水锅炉管板有限元分析 总被引:3,自引:0,他引:3
以大连锅炉厂DZW4.2-0.7/95/70-AⅡ型热水锅炉为例,对该锅炉平管板采用了有限元弹塑性分析,同时与人孔周边电测结果进行了比较,给出了管板上强度危险区域的范围及最大应力值。 相似文献
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A finite element analysis is performed to investigate the stability boundaries of thermal buckling in automotive clutches. It is found that the radial variation of temperature considerably affects the critical buckling temperature. A linear or monotonic temperature profile always leads to a dominant coning mode. Whereas a temperature profile with the maximum temperature located in the middle leads to a dominant non-axisymmetric buckling mode, and the associated critical temperature is typically much higher. The numerical solutions for periodic variations of temperature with multiple waves along the circumference were also tentatively obtained. 相似文献
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Numerical analysis has been done to investigate magnetohydrodynamics nonlinear convective flow of couple stress micropolar nanofluid with Catteneo‐Christov heat flux model past stretching surface with the effects of heat generation/absorption term, chemical reaction rate, first‐order slip, and convective boundary conditions. The coupled highly nonlinear differential equation governing the steady incompressible laminar flow has been solved by a powerful numerical technique called finite element method. The impacts of diverse parameters on linear velocity, angular velocity (microrotation), temperature, concentration profile, local skin friction coefficient, local wall couple stress, local Nusselt number, and Sherwood number are presented in graphical and tabular form. The result pointed out that the enhancement in material parameter β increases the velocity of the fluid while the couple stress parameter K has quite opposite effect. Heat and mass transfer rate of the fluid are enhanced by increasing material parameter while couple stress parameter shows the opposite influence. Moreover, heat and mass transfer rate are higher with the Catteneo‐Christov heat flux model than Fourier's law of heat conduction. The accuracy of the present method has been confirmed by comparing with previously published works. 相似文献
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转化气余热锅炉入口温度达到860℃,管壳程温差载荷较大,管板承受内压和温差载荷的双重作用,在管板管程侧、换热管管板部位和旁通管内部设计了防热材料,管板的管壳程的连接结构采用H型锻件,在温差载荷和管壳程设计压力相互作用的三种工况条件下,依据JB4732对设备相应部位进行应力评定,评定结果合格,为工程设计人员提供可参考的数据。 相似文献
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采用有限元法建立了基于某电厂汽轮机转子温度场和热应力场的数学模型。在对汽轮机的冷态启动、温态启动、热态启动以及滑参数停机4个工况下的瞬态温度场以及热应力场进行模拟分析基础上,确定转子最大热应力点作为监测点,对监测部位的温度与热应力进行了疲劳损耗仿真计算。根据最小二乘法获得转子钢材料的疲劳特性曲线,利用MATLAB进行多项式拟合,获得转子应变与疲劳寿命损耗的函数关系式,求得汽轮机转子启停下的低周疲劳寿命。研究结果表明:该机组累积十年运行条件下形成的疲劳损耗为2. 506%。机组冷态启动过程中,转子承受最大温差与热应力,最大热应力值445 MPa;当温升率由3℃/min提高到4℃/min时,转子的低周疲劳寿命损耗由0. 040%上升到0. 103%,寿命损耗明显增大。 相似文献
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全玻璃真空管太阳热水器数值模拟研究 总被引:2,自引:0,他引:2
基于FLUENT软件及TECPLOT软件,通过对均匀加热条件下的全玻璃真空管太阳热水器内流场及温度场的数值模拟,研究了热水器的对流换热与传质过程;分析了集热管倾角、真空管双面受热对热水器内流场及温度场的影响和真空管与水箱连接处、垂直等温面上的流体速度、温度分布。结果表明,在真空管与水箱连接处出现随机的涡流和真空管内出现分段的小环流,对传热传质过程不利,特别是对于带反射板的双面受热的集热器,应采取措施确保管内对流换热流动的有序性。建议加装导流板,并初步探讨了导流板的长度,确立了最佳板长模拟结构,为后续的理论研究与试验打下基础。 相似文献
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对改进的ZH1105W型柴油机缩口四角ω燃烧系统,利用热电偶法实测了标定工况下活塞顶面、侧面和内腔共16个特征点的温度。用Pro/E建立活塞几何模型,选取热结构耦合单元,并对模型网格进行了优化,结合试验值对活塞进行热分析计算,得到活塞三维温度场、热应力场和变形。计算结果表明,在标定工况下,活塞最高温度出现在燃烧室喉部达到310.7℃,最大von Mises热应力出现在排气一侧的回油孔顶部,为68.4 MPa,最大热变形量出现在活塞顶面边缘排气口侧,达到0.328 mm,这为活塞的结构改进和优化提供了依据。 相似文献
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Basim Freegah 《亚洲传热研究》2023,52(2):1118-1141
In this paper, improving the thermal performance of flat plate solar water heater systems by inserting different tube configurations inside the riser pipes has been numerically and experimentally studied. This study is focused on increasing the moving of energy from riser pipes to the operating fluid within the riser pipes. To achieve that, the diameter of the riser pipes was increased along with the insertion of different tube configurations within them, namely, smooth, helical, and wavy tubes, keeping the same amount of the operating liquid. A comparison was performed to determine the best in terms of coefficient of heat transfer of the operating liquid, mass flow rate of the operating liquid, pressure drop, and water temperature in the storage tank, as a thermal performance indication of the system under study. The findings show the model consisting of a straight tube inside the riser pipe provides the best thermal performance. In terms of thermal performance, the straight model outperforms the conventional model by 12.3%. An experimental and numerical comparison between the optimum model (straight model) was conducted. The study proves that the average difference between numerical results and experimental findings is 7.2%. 相似文献