U 型管废热锅炉沸腾传热恶化及其消除

BOILING HEAT TRANSFER DETERIORATION AND ITS ELIMINATION FOR U-SHAPED WASTE HEAT BOILERS

本文针对大型合成氨装置 U 型管转化气废热锅炉爆管问题,在高压电加热水回路试验系统上研究了垂直 U 型管弯管段沸腾传热特性,得出了发生传热恶化的规律和壁温飞升特性,提出了用管内扰流子及改进 U 型管结构来消除传热恶化,以保证U 型管废热锅炉工作的可靠性.

Vertioal U-shaped tubes have been used in some waste heat boilers of large synthetic ammonia plants.In operation,accidents of tube failure at the bend due to overheating ocour frequently.In order to Solve the problem,a study of boiling heat transfer in the bend of vertical U-shaped tube in an electrically heated high pressure water loop was conducted,the law of boiling heat transfer deterioration and the wall temperature rice performanoe were obtained,and an inserted turbu- lator and modified U-shaped tubes With inclined upward bottom were recommen- ded for waste heat boilers to eliminate the boiling heat transfer deterioration in synthetic ammonia plants for ensuring safety operation.