Abstract: The tube layout is one of the most important and most easily overlooked factors affecting the flexibility of the flexible thin tube sheet. The rationality of the tube layout directly determines the service life of the flexible thin tube sheet.Different finite element analysis models were established for the flexible thin tube sheet in a waste heat boiler and were analyzed under multiple working conditions to obtain various stress levels and stress distribution of the flexible thin tube sheet. According to the main parameters of the tube layout including the tube pattern, the tube pitch and the limit circle diameter of tube layout, the influence rules of various factors on the stress intensity of flexible thin tube sheet were obtained. The analysis results show that the stress level of flexible thin tube sheet can be effectively improved by optimizing the tube layout reasonably. The results are instructive for the engineering design of flexible thin tube sheet.

Key words: HRSG (Heat Recovery Steam Generator), flexible thin tube sheet, tube layout, stress field