KIER (Korea Institute of Energy Research) has developed three supercritical carbon dioxide power cycle test loops since 2013. After developing a 10 kWe-class simple un-recuperated Brayton cycle, a second sub-kWe small-scale experimental test loop was manufactured to investigate the characteristics of the supercritical carbon dioxide power cycle, for which a high speed radial type turbo-generator was also designed and manufactured. Using only one channel of the nozzle, the partial admission method was adopted to reduce the rotational speed of the rotor so that commercial oil-lubricated bearings can be used. This was the world’s first approach to the supercritical carbon dioxide turbo-generator. After several tests, operation of the turbine for power production of up to 670 W was successful. Finally, an 80 kWe-class dual Brayton cycle test loop was designed. Before completion of the full test loop, a 60 kWe axial type turbo-generator was first manufactured and our previous 10 kWe-class test loop was upgraded to drive this turbo-generator. Due to leakage flow through the mechanical seal, a make-up loop was also developed. After assembling all test loops, a cold-run test and a preliminary operation test were conducted. In this paper, the power generating operation results of the sub-kWe-class test loop and the construction of the tens of kWe-class test loop which drives an axial type turbo-generator are described.
An experimental investigation on pressure response and phase transition of supercritical carbon dioxide releases from a small-scale pipeline
