The influence of structure parameters on stress of plate-fin structures in LNG heat exchanger

Abstract

In order to ensure the structural safety of plate-fin structures in actual operation process and guide the structural design of LNG plate-fin heat exchanger, the influence of structure parameters was investigated on stress of plate-fin structures based on Finite Element Method and thermal elastic theory. The results show that the stress is complex at the brazed joints in actual operation process of LNG PFHE and the equivalent stress will reach the peak value at brazed joint near fin side due to the influence of the direct stress in y direction. Meanwhile, the peak value of equivalent stress in plate-fin structures is slightly impacted by the fin height and plate thickness and is obviously impacted by the brazing seam thickness, fin thickness and fin distance. The influence of the brazing seam thickness, fin thickness and fin distance for that is mainly induced by the direct stress in y direction. These results will provide some constructive instructions in the structural design for plate-fin heat exchanger in a large-scale LNG cold-box.