Development of a Hundreds of kWe-Class Supercritical Carbon Dioxide Power Cycle Test Loop in KIER

The supercritical carbon dioxide (S-CO2) power cycle has been a topic of interest because it exhibits a high efficiency and compact size and is compatible with any heat source. Since 2013, the Korea Institute of Energy Research (KIER) has developed three S-CO2 power cycle experimental test loops for distributed power source applications. Based on this experience, a hundreds of kWe-class dual Brayton test loop with a maximum temperature of 500 °C has been designed and partially fabricated. This cycle consists of two turbines, one compressor, two recuperators, and a flued-gas heater. First, a relatively low-temperature turbine with an inlet temperature of 392 °C was designed and manufactured as an axial impulsetype turbo-generator because of the cost and development time required for construction of a full-cycle test loop. As a preliminary step, the turbo-generator was successfully tested in 2017. Next, it was continuously operated for 4.2 h in 2018. In addition, the following components were designed and manufactured: a centrifugal compressor with a dry gas seal; oil-lubricated tilting-pad bearings; a flued-gas heater, which consists of a burner and a shell-and-tube heat exchanger; and two printed circuit heat exchanger type recuperators. The full cycle is expected to be operational in November 2019.