Check and optimization of stress on nozzle of centrifugal compressor in China-Russia Eastern Gas Pipeline

Centrifugal compressor system is known as the heart of a gas transmission station. To adapt to the design trend of compressor with large diameter, high pressure and high temperature difference, and to meet the requirement for smaller allowable stress on nozzle of domestic compressor, it is necessary to optimize the stress check of nozzle. The stress analysis model for compressor area in a gas transmission station was built using pipeline stress analysis special software CAESAR II based on initial piping installation scheme and the stress check requirement of compressor nozzle in Axial and centrifugal compressors and expander-compressors (API 617-2014). The influence of natural compensation setting, type and position of pipe support on the stress of compressor nozzle in x, y and z directions was analyzed by the model, and the stress on nozzle was checked and optimized. The research shows that the stress in x, y and z directions of the nozzle was the key factor affecting the stress on nozzle. By increasing reasonable natural compensation and the type of pipe support, the key technical optimization scheme for reducing the stress in x, y and z directions of the compressor nozzle was proposed to significantly reduce the stress on nozzle of the centrifugal compressor. The stress optimization scheme based on one gas transmission station in China-Russia Eastern Gas Pipeline can be applied to the stress check of inlet and outlet nozzles of compressors with different diameters. The research is of great significance for reducing stress on the compressor nozzle, enhancing the operation safety of the compressor, improving the stress analysis level of the centrifugal compressor system, and raising the design efficiency.