【作者】 李玉洁；

【导师】 徐宏海；

【作者基本信息】 北方工业大学 ， 机械制造及其自动化， 2009， 硕士

【摘要】 调节阀泄漏一直是个难题,同时电动调节阀执行机构承受的温度也有严格要求。所以密封性和控制性能好坏是电动调节阀能否正常使用的两个关键因素。则准确获得电动调节阀温度场具有一定的指导意义,在此基础上期望对未来的电动调节阀早期设计方面做一些有益的探索,减少盲目设计和试验成本。三通电动调节阀模型采用三维装配体结构。分析中采用了直接耦合方法和序贯耦合方法。首先应用PRO/E三维软件进行建模,其次通过ANSYS有限单元法分析软件得出电动调节阀三维稳态温度场及部分组件的热应力场。在电动调节阀边界条件的确定上,外界自然对流换热采用了常壁温的保守计算方法,而辐射发射率则参考了相关的热学数据。温度场分析采用了三种方法:热流耦合、直接施加对流换热系数和直接施加温度。设置流体温度和直接施加的温度为290℃,则三种温度场的分析结果表明:1)热流耦合分析所得温度大于施加对流换热系数所得温度,小于直接施加温度所产生的最大温度。虽然热流耦合分析出的温度场最为准确,但是热流耦合所获得的温度场耗费时间太长,同时考虑到热学平衡原理,可以直接采用施加温度的方法进行模拟仿真。2)辐射散热是电动调节阀散热的主要途径。故改自然对流为强迫对流或者把阀盖的直筒结构改为散热片结构都能有效降低电动调节阀执行机构的温度。电动调节阀热应力分析表明:1)单独分析时,阀体和阀座阀芯组件的热应力在许用应力范围之内,但阀体整体分析时却大于许用应力的范围:2)填料处的最大应力远超过材料许用应力,说明填料已经发生了塑性变形,需要进行弹塑性分析。更多还原

【Abstract】 The leak of control valve is a hard problem to deal with, and the temperature in the actuator has a serious requestion.So that the seal and the control about the electric control valve are good or bad is a key factor, which refers to the distribution of the temperature. Then it is a guiding significance to gain the thermal field of the control valve. On this basis, we look forward to doing some beneficial research about forepart design for the future to reduce the blindfold design and experiment cost.The model, three way type of electric control valve, is a three-dimensional combinational construction. During the analysis, direct coupling method and sequence coupling method are used. The model of electric control valve is built by PRO/E three-dimensional software firstly, and then three-dimensional static temperature field and the stress fields about some parts are obtained by ANSYS with FEA solution. In the aspect of ascertaining the boundary condition of electric control valve, the natural convection outsides is calculated conservatively with constant wall temperature and the emissivity is got by relative manuals.There are three methods to analyze the thermal field of electric control valve: the heat-flow coupling, the thermal field with being loaded forced convection, the thermal field with being loaded directly the temperature. The fluid temperature and the temperature loaded directly are both 290℃.The results indicate that: 1 ) The temperature gained in the single thermal field with the convection heat transfer is lower than the temperature gained in single thermal field with temperature 290℃,and the temperature gained in single thermal field is the highest. Although the thermal field gained with heat-flow coupling is the most reliable result, the thermal field gained with the method of heat-fluid coupling takes much time.And considering the principle of thermal balance, the temperature can be applied directly to simulate to gain the result. 2) Thermal radiation is the main way to cool the electric control valve off. So it is an effective way to dissipate the temperature on the actuator of the electric control valve by shifting the natural convection into forced convection or changing the straightly barrel-shaped structure into the plate-fin structure. The thermal stress analysis of electric control valve indicates that:1) The stress value of the body and the disc with the seat rings are under the allowable stress when they are analyzed alone, but when being analyzed with the whole model, the body is not;2) The stress in the packing rings is far above the allowable stress. It shows that the packing rings are under the plastic deformation and should be analyzed with the method of the elasto-plasticity.更多还原