Technical and Aerodynamical Aspects of a High Pressure Synthesis Gas Turbocompressor Modernization

The article is devoted to the description of the modernization of a multihull process centrifugal compressor for synthesis gas. The main reason for the revamp was the desire to adapt the conventional machine (45 years of operation) for newer operational requirements: the decrease of compressor discharge pressure to the level of 140 bar from the level of 211 bar with the corresponding alteration of the mass flow rate. The scheme accepted as a final modernization conception required the manufacturing of three completely new rotor and casing assemblies. Major design modifications concerned the impellers’ geometry, introduction of vaneless diffusers and the abradable labyrinth seals. Most of the stages were “optimized” using the in-house semi-empirical 1D code and ANSYS CFX commercial code. The performance of a single optimized stage was tested experimentally. The paper reveals the main results of these measurements and their comparison to numerical simulations results. The start-up tests of the modernized assembly showed its almost 100% conformity to the requirements in the output and the efficiency rise of about 5%.