Dynamic characteristics analysis on the welded casing of large scaled axial flow compressor

On the basis of the established welded casing finite element model of large scaled axial flow compressor, contact problems between step surface of linking bolt and flange surface of upper casing and between upper and lower casing flange surfaces and pre-tightening problem of bolt have been processed.

Based on the finite element(FE) model of welded casing for large axial compressor,the problem of surface-contact between bolted flange & the top casing flange and the top casing flange & bottom casing flange as well as the problem of pre-load of bolts were dealt with in this paper.

Welding casings are made of 09MnNiDR low temperature steel material, which is applied in welding casing of compressor produced by our company for the first time.

With the quick development of diversity and small batch of products, the substitute of traditional cast casing by the welding casing for large compressors is the requirement due to shortening the period of making, reducing production cost and winning the market.

The paper focuses on describing and analyzing the distribution and deforming regularity of the internal stress of the joining bridge shell (banjo axle) in the processing, which lead to the transmutation of the bridge shell and affect its precision of dimension, geometry and position.

This paper also analyzes the weldability of this steel and details its welding methods,welding technologies and quality control measures should be taken in welding process,and introduces the welding technology and quality control of welded shell made of this kind of steel.