Research on structural strength for hot water circulation pump based on thermal-structural coupling

Hot water circulation pump is widely used to various pressurization equipments. The structural safety and reliability closely relates to the normal operation of whole unit. A thermal-structural coupling method is applied to verify the structural reliability of hot water circulation pump. Based on the pump performance test, temperature, the equivalent stress and total deformation of the structure, under different medium temperature conditions, are calculated respectively. The temperature and absolute pressure of the fluid domain are also calculated when the medium temperature changes. Then, the effect of different medium temperature on each quantity is analysed. Based on the fourth strength theory, the strength check analysis in the pump casing structure is implemented. The results show that the values of equivalent stress and deformation, caused by temperature load, are greater than ones, caused by pressure load. The effect of temperature on structural strength can not be ignored especially for the medium temperature higher than the room conditions. With medium temperature rising, the structural temperature of pump increases. The temperature in pump body is higher than the one in pump bracket. But the gradient of temperature is smaller. The position of stress concentration is located at the tongue. Therefore, confirming the shape and location of the tongue is particularly important in the process of designing. The strength check result shows that the pump casing structure can meet the strength requirement when the medium temperature equals to 25℃ and 40℃ respectively. © 2014 Journal of Mechanical Engineering