为保证大型LNG冷箱降温过程中板翅式换热器结构安全可靠,建立了板翅结构应力耦合分析模型,采用热-结构直接耦合模拟方法,分析了降温过程对板翅结构应力的影响规律. 结果表明:翅片和隔板钎焊接头处为结构最易破坏区;温差对板翅结构应力影响较为明显,并随温差增大而增大;当温差小于10 K时,对流换热性能对板翅结构应力影响较小;当温差相等时,降温速率对板翅结构应力影响较小.%In order to ensure the structural safety of plate-fin heat exchanger, a model was proposed to simulate the stress of plate-fin structures in the cool-down process. The stress of plate-fin structures was investigated in the cool-down process based on directly coupled Finite Element Method. The results showed that the most easily damaged area happened in the brazed joint between fin and plate in the cool-down process. At the same time, the stress was obviously influenced by the temperature difference between natural gas ( NG) and mixture refrigerant ( MR ) and increased with increasing temperature difference. The heat transfer performance had little influence on the stress of plate-fin structures when the temperature difference between NG and MR was less than 10 K. The stress of plate-fin structures was also slightly impacted by the temperature drop rate as the temperature drop rate of NG was the same as that of MR in the cool-down process.
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