KIER의 초임계 이산화탄소 동력 사이클 연구 현황

In response to the growing interest in supercritical carbon dioxide (S-CO2) power cycle technology because of its potential enhancement in compactness and efficiency, the S-CO2 cycles have been studied intensively in the fields of nuclear power, concentrated solar power (CSP), and fossil fuel power generation. By utilizing carbon dioxide’s property changes near the critical point, the compression work can be reduced, which results in a significant efficiency improvement. In this study, the current status of the research project on the supercritical carbon dioxide power cycle in KIER (Korea Institute of Energy Research) was introduced. During the first phase of the project, the un-recuperated supercritical Brayton cycle, which was designed to have a net power of 12.6 ㎾, was built. The cycle was composed of the turbo-alternator-compressor unit (TAC) of maximum speeds of 70,000 rpm, two PCHEs (Printed Circuit Heat Exchangers) and a thermal oil heater of capacity of 697 ㎾. The maximum design pressure and temperature of the cycle was 135 bar and 180℃, respectively, while the minimum of those was 79 bar and 35.9℃, respectively. After a successful cold-run test of the TAC unit at a target spin speed of 70,000 rpm, the cycle test loop was test-run up to the spin speed of 30,000 rpm with supercritical CO2. In the second phase of the project, the recuperated supercritical Brayton cycle has been being optimized and designed.