Lanterna Rally

Author: Chang Oh

Publisher:

Published: 2004

Total Pages:

ISBN-13:

The Idaho National Engineering and EnvironmentalLaboratory (INEEL) is investigating a Brayton cycle efficiencyimprovement on a high temperature gas-cooled reactor (HTGR)as part of Generation-IV nuclear engineering research initiative. In this project, we are investigating helium Brayton cyclesfor the secondary side of an indirect energy conversion system. Ultimately we will investigate the improvement of the Braytoncycle using other fluids, such as supercritical carbon dioxide. Prior to the cycle improvement study, we established a numberof baseline cases for the helium indirect Brayton cycle. Thesecases look at both single-shaft and multiple-shaftturbomachinary. The baseline cases are based on a 250 MWthermal pebble bed HTGR. The results from this study areapplicable to other reactor concepts such as a very hightemperature gas-cooled reactor (VHTR), fast gas-cooled reactor(FGR), supercritical water reactor (SWR), and others. In this study, we are using the HYSYS computer code foroptimization of the helium Brayton cycle. Besides the HYSYSprocess optimization, we performed parametric study to see theeffect of important parameters on the cycle efficiency. Forthese parametric calculations, we use a cycle efficiency modelthat was developed based on the Visual Basic computerlanguage. As a part of this study we are currently investigatedsingle-shaft vs. multiple shaft arrangement for cycle efficiencyand comparison, which will be published in the next paper. The ultimate goal of this study is to use supercriticalcarbon dioxide for the HTGR power conversion loop in orderto improve the cycle efficiency to values great than that of thehelium Brayton cycle. This paper includes preliminary calculations of the steadystate overall Brayton cycle efficiency based on the pebble bedreactor reference design (helium used as the working fluid) andcompares those results with an initial calculation of a CO2Brayton cycle.