The Research on Compressor Performance Degradation Caused by Surface Roughness Enlargement due to Corrosion in Marine Environments

Abstract

Abstract In the marine environment, the corrosion on a compressor blade caused by salt spray severely affects the compressor performance and poses a threat to its operation reliability. This study simulated the corrosion on the blade made of X20Cr13 martensitic stainless steel caused by salt spray by using the static acceleration test. Average depth and density of surface corrosion pit were calculated by the actual corrosion with peak valley and different shapes and sizes. The value of average deviation Ra was calculated by average depth and density of corrosion pit. According to the empirical formula proposed by Koch and Smith (ks = 6.2 Ra), setting the equivalent sand grain roughness ks in CFX. NASA Stage67 as calculation model. Then analyzed the effects of various surface roughness on compressor performance and internal flow field through the numerical simulation method. The results revealed that with the increase in corrosion time, the flow rate, pressure ratio, torque, and power of the compressor decreased. The internal flow indicated the increasing internal loss and decreasing efficiency. On the basis of loss analysis, the binomial relationships between the service time and relative values of total pressure loss and efficiency loss, respectively, were established.