500 kW supercritical CO2 power generation system for waste heat recovery: System design and compressor performance test results

Abstract

• A 500 kW supercritical CO 2 power generation system for waste-heat recovery was designed. • Magnetic bearings were adopted to protect the high-speed shaft. • Operating at the design conditions of the compressor was accomplished during the compressor performance test. The supercritical CO 2 Brayton cycle has received attention as a next generation power conversion system. However, technical challenges that relate to the design and operation of the system remain to be overcome. In particular, achieving turbomachinery operation with design points is imperative to demonstrate the feasibility of the technology. This study aims to provide the current research status of the supercritical CO 2 power generation system in KAERI, with a focus on the detailed design of the system and operation of the compressor. In this study, cycle design (a simple recuperated cycle layout) of the system was developed using an in-house code for the optimization of a pilot plant of a 500 kW supercritical CO 2 power generation system for waste heat recovery. A thermal efficiency of 16.5% of the proposed cycle was achieved. In addition, the detailed design of key components, such as turbomachines and heat exchangers, was developed. Furthermore, the first-step configuration, a compressor performance test loop, of the supercritical CO 2 power generation system pilot plant was accomplished. The compressor was designed and manufactured as a hermetic system for the supercritical CO 2 power generation system. A compressor performance test was conducted to verify the target performance of the compressor. The operation of the compressor at the design point was achieved during the test; the compressor inlet was 33 °C at 7.68 MPa, and the compressor rotational speed was 34200 rpm; its efficiency was 83.7%, and the pressure ratio was 1.756.