Experimental and Computational Studies on Cryogenic Turboexpander

Abstract

The expansion turbine constitutes the most critical component of a large number of
cryogenic process plants – air separation units, helium and hydrogen liquefiers, and low
temperature refrigerators. A medium or large cryogenic system needs many components,
compressor, heat exchanger, expansion turbine, instrumentation, vacuum vessel etc. At present
most of these process plants operate at medium or low pressure due to its inherent advantages.
A basic component which is essential for these processes is the turboexpander. The theory of
small turboexpanders and their design method are not fully standardised. Although several
companies around the world manufacture and sell turboexpanders, the technology is not
available in open literature. To address to this problem, a modest attempt has been made at NIT,
Rourkela to understand, standardise and document the design, fabrication and testing procedure
of cryogenic turboexpanders. The research programme has two major objectives –
⇒ A clear understanding of the thermodynamic scenario though modelling, that will help
in determination of blade profile, and prediction of its performance for a given speed
and size.
⇒ To build and record in open literature a complete turbine system.