Journal Article

Numerical Investigation on Thermal Fatigue Damage Mechanism of Head Structures in Aluminum Plate-Fin Heat Exchangers

Chen, Hailiang, Wang, Shengxun, Ding, Ruixiang, Cai, Weihua, Ma, Hongqiang, Wang, Jiajun, Bai, Jihua

2024

Overview

In order to ensure the structural safety of liquefied natural gas (LNG) aluminum plate-fin heat exchangers, a model is established to simulate the thermal–structural stress characteristics of head structures based on thermal-elasticity theory and finite element method of thermal–structural coupling. The results show that the area with the lowest temperature and largest equivalent stress is located on the inner wall of connection position between the nozzle and head body, and its temperature and stress are obtained as 92.1 K and 117.4 MPa, respectively. The influences of different operating and structural parameters on the fatigue life are compared and analyzed for head structures. The results show that for operating parameters, the fatigue life of head structures becomes shorter with the increase in operating pressure. For structural parameters, the fatigue life of head structures is positively correlated with nozzle opening rate and negatively correlated with cylinder radius-thickness ratio. In addition, the fatigue life of head structures is obtained based on the S - N model, third and fourth strength theories. The results show that compared with traditional assessment methods, most of data points calculated by this standard are within the error range of ± 60% and the BS PD5500 standard is proposed for fatigue life calculation of head structures in engineering. That is, the analysis results of BS PD5500 standard can be considered relatively accurate and reliable. This is because the fatigue analysis process mainly focuses on the simulations, and there is a certain error range during simulation process, which is normal for the results. The above research results provide an important theoretical basis for the structure design optimization of LNG aluminum plate-fin heat exchangers in engineering.

• Publisher: Springer US,Springer Nature B.V
• Subject: Aluminum / Characterization and Evaluation of Materials / Chemistry and Materials Science / Corrosion and Coatings / Cylinder heads / Data points / Design optimization / Engineering Design / Fatigue failure / Fatigue life / Finite element method / Heat conductivity / Heat exchangers / Heat transfer / Influence / Liquefied natural gas / Materials Science / Metal plates / Methods / Nozzles / Original Research Article / Parameters / Plate-fin heat exchangers / Quality Control / Reliability / Safety and Risk / Simulation / Stress analysis / Stress concentration / Structural safety / Symmetry / Thermal fatigue / Thickness ratio / Tribology / Yield stress