Computational Fluid Flow Analysis of Cryogenic Turboexpander

Abstract

Cryogenic turboexpander is the most critical component of cryogenic plant to achieve low temperature refrigeration. A cryogenic turboexpander has many components like expansion turbine, compressor, heat exchanger, instrumentations etc. Expansion turbine is the component where temperature of gases decreases due to expansion and produce the coldest level of refrigeration in the plant. This project deals with the computational fluid flow analysis of high speed expansion turbine. This involves with the three dimensional analysis of flow through a radial expansion turbine using nitrogen as flowing fluid. This analysis is done using cfd packages, bladegen, turbogrid and CFX. Bladegen is used to create the model of turbine using available data of hu b, shroud and blade profile. Turbogrid is used to mesh the model. CFX-Pre is used to define and specify the simulation settings and physical parameters required to describe the flow through turboexpander at inlet and outlet. CFX-Post is used for examining and analyzing results. Using these results variation of different thermodynamic properties inside the turbine can be seen. Various graphs are potted indicating the variation of velocity, pressure, temperature, entropy and Mach number along streamline and span wise to analyze the flow through cryogenic turbine.