Development of the Supercritical Carbon Dioxide Power Cycle Experimental Loop With a Turbo-Generator

Abstract

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.

Review of Experimental Research on Supercritical and Transcritical Thermodynamic Cycles Designed for Heat Recovery Application

“…Selected Brayton architectures were standard closed Brayton and dual Brayton. In the course of their experiment they designed and built a small-scale high speed turbo-generator (1 kWe, 200 kRPM) for a multi-purpose test loop which could operate at high temperature (500 • C) as simple Brayton and at low temperature (200 • C) as a transcritical Rankine cycle [80].…”

“…Initial testing took place without the power turbine, and off-design performance of components were measured and data recorded in comparison with model predictions showed in good agreement. At the KAERI, a simple Brayton was tested [79,80]. The test rig comprises an oil loop, a double low-pressure motor-compressor unit, a power turbine (200 kW power output) and a pre-cooler.…”

A review of research on turbines for supercritical carbon dioxide power systems

“…Korea Advanced Institute of Science and Technology (KAIST) reported on their experiences of troubleshooting and operation with the S-CO2 Pump Experiment facility (SCO2PE) [25]. KIER (Korea Institute of Energy Research) developed three S-CO2 power cycle test loops with power levels of 10kWe, sub kWe, and 80kWe [26]. Moore et al designed a high-temperature and high-pressure S-CO2 flow circuit with a flow rate equivalent to 1 MWe [27].…”

Demonstration of a small‐scale power generator using supercritical CO2

“…The Korea Institute of Energy Research (KIER) has constructed sCO 2 power cycle test loops since 2013. 48 Three stages can be observed: the 10 kWscale (2013-2014), the sub-kW-scale (2014), and the 100 kW-scale (2015) layouts. A sub-kW test loop was used to evaluate the cycle characteristics and control strategy.…”