Session: 33-09 sCO2 Testing and Component Development

Paper Number: 83284

83284 - Design and Testing of a 275 Bar 700 Degree Celsius Expander for an Integrally Geared Supercritical CO2 Compander 

Recently, our team developed an integrally-geared (IG) compressor-expander (compander) for use in a nominal 10 MW-scale concentrated solar power (CSP) supercritical carbon dioxide (sCO₂) plant application. This integrally-geared compander (IGC) comprises multiple pinion shafts interacting through a single bull gear to create a compact package and utilize a low-cost, low-speed driver. In addition, the IG architecture allows each pinion to operate at different rotational speeds to optimize performance and easily allow for inter-stage cooling and turbine reheat to further enhance both stage and cycle efficiency. The close integration of all turbomachinery elements into a single IG machine creates a design that lends itself to power-block modularization, which makes it suitable to a variety of applications including waste heat recovery, fossil fuel power plants, and especially CSP applications.

The present work will detail the design of the high temperature turbine and how the process was managed to reduce the probability of fatigue, creep, meanwhile allowing for rapid thermal transients in the design.  Futhermore, test data from the test campaign will show data supporting that this technology is ready for commercialization, reaching both the design temperature and design pressure at full speed.  The expander detailed in this paper is believed to be the highest indirectly fired integrally geared machine in the world in CO2, and represents a step change in the potential viability for sCO2 machinery.

Presenting Author: Karl Wygant HPSA

Presenting Author Biography: Jason Wilkes is Presenting this paper

Authors:

Jason Wilkes SOUTHWEST RESEARCH INSTITUTE
Karl Wygant HPSA
Rob Pelton HPSA
Jon Bygrave HPSA
Kyle Robinson Southwest Research Institute