Development of a High Pressure Linear expander/generator for sCO2 Brayton Cycle.
The increasing electricity demand and cost, in addition to the increasing global energy demands, are the main motivations in seeking for sustainable new technologies in the ﬁeld of energy conversion and utilization. Various thermodynamic cycles, such as organic Rankine cycle (ORC), supercritical Rankine cycle, supercritical Brayton cycle, have been proposed to convert heat sources into electricity. There has been a significant research in sCO2 Brayton throughout the world including India. The application for sCO2 Brayton cycle to generate electricity from a wide variety of heat sources include natural gas, solar energy, geothermal energy, and waste heat from a variety of industrial processes and internal combustion engine. For large systems (> 10 MW), typically axial turbine expanders are the preferred design. However there is a significant need for systems less than 1 MW. Given the high power density of sCO2, rotary expanders are not practical due to its high speed resulting in low efficiencies and high capital costs. A linear expander can address this need. The development of a cost effective positive displacement expander that is not only efficient but also inexpensive is critical for the success of small scale sCO2 electricity generation systems