Carbon dioxide is increasingly gaining attention from the energy industry as an alternate working fluid for power generation to produce low-cost electricity from natural gas or synthetic gas from coal gasification while generating near-zero atmospheric emissions, including full carbon dioxide capture. Carbon dioxide in the supercritical phase possesses properties that impart it high potential to replace traditional power cycles. High density and low compressibility near critical point that is close to standard atmospheric temperature are the key drivers for carbon dioxide applications. The dramatic variation of properties like specific heat capacity, density, thermal conductivity, viscosity, etc. presents challenges in the further development of this cycle and invokes failure modes in the transient operations. Dynamic modeling characterizes the failure modes and enhances the understanding of problems introduced because of the transient events. This dissertation presents a dynamic model for recuperated Brayton power cycle using Simcenter Amesim. Amesim is a commercial simulation software for the modeling and analysis of multi-domain systems developed by Siemens Digital Industries. Impact on the operation of air cooler and compressor due to varying air conditions and varying power demand is demonstrated here. Non-linear temperature distribution, reduction in compressor surge margin and high rate of mass transfer are the issues characterized during transient events. The need for controlling the mass in the closed loop is manifested here. Advanced control logic and instrumentation will be required for a safe and successful transition from one state of operation to next.
Doctor of Philosophy (Ph.D.)
College of Engineering and Computer Science
Mechanical and Aerospace Engineering
Length of Campus-only Access
Doctoral Dissertation (Campus-only Access)
Deshmukh, Ankur, "Dynamic Modeling Of Supercritical Carbon Dioxide Brayton Cycle For Transient Analysis" (2020). Electronic Theses and Dissertations, 2020-. 434.