The influence of different thermal load models on the strength of an isothermal reactor tube sheet

In order to improve the safety and economy of lightweight designs of large pressure vessel tube sheets, the effects of temperature load model, convection load model and fluid-solid coupling load model on the temperature field and stress field of isothermal reactor tube sheets have been compared through numerical simulation. The stress distribution rule at the key position of the tube sheet was obtained, and the equivalent stress of each model was evaluated by means of the pressure vessel standard. The results show that the temperature gradient of the tube sheet of the temperature load model is the largest, and the stress concentration of the tube sheet is the most prominent. The temperature gradient of the tube sheet of the fluid-solid coupling load model is the smallest, and the stress concentration of the tube sheet is greatly alleviated. The local film stress and the primary + secondary stress of the tube sheet increase with the increase of the temperature gradient of the tube sheet. The two stresses of the temperature load model are 36.49 MPa and 155.73 MPa, respectively. The two stresses of the convection load model are 31.40 MPa and 132.74 MPa, respectively. The two stresses of the fluid-solid coupling load model are 27.84 MPa and 112.84 MPa, respectively. Compared with the other two thermal load models, the stress of the tube sheet calculated by the fluid-solid coupling load model corresponded more closely to actual conditions, and the reliability of the optimized design of the large pressure vessel tube sheet was the highest.