【China’s First】China’s first large-scale supercritical carbon dioxide compressor experimental platform has been built and put into operation

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China’s First Large-Scale Supercritical Carbon Dioxide Compressor Test Platform Completed and Put into Operation, Voice of the Chinese Academy of Sciences, September 30, 2018. Good news has come from the Hengshui site of the Institute of Engineering Thermophysics, Chinese Academy of Sciences: the team working on new working fluids for power generation has completed the construction of China’s first large-scale supercritical carbon dioxide (SCO2) compressor test platform. A completion summary meeting was held on September 21, and equipment calibration has now been finished; preparations are underway ahead of the compressor tests. Supercritical carbon dioxide turbine power generation is internationally recognized as a revolutionary and groundbreaking new generation of power generation technology. In recent years, it has received widespread attention from the scientific community and the high-end equipment manufacturing industry; many companies and research institutions both at home and abroad are actively carrying out or initiating research in this area. The compressor is the \"heart\" of the SCO2 power generation system. Due to the unique physical properties of the SCO2 working fluid, which undergo significant changes near its critical point, the applicability of traditional turbine design theories is called into question. The associated technologies, such as high-speed rotors, high-pressure seals, and bearings, also require testing and verification. Many domestic institutions have carried out extensive research on the design theories and computer simulation of SCO2 compressors, but the lack of a suitable experimental platform has prevented experimental verification, thus hindering the progress of SCO2 compressor development in China. SCO2 compressor test benches, especially those of the MW class and above, present a challenging task in terms of design, construction, and operation due to the involvement of high-pressure equipment, special gases, and closed-loop operations. In recent years, the research institute has focused its efforts on developing the key technologies and experimental units for supercritical carbon dioxide turbine power generation. Since the commencement of experimental research, it has regarded the development of compressors and turbines as well as the establishment of experimental facilities as top priorities. The experiment platform built this time is a general-purpose platform used to test the operational performance of SCO2 compressors and conduct basic experiments related to the compression properties of SCO2 fluids; it can also be used for experiments such as high-speed rotor testing, bearing testing, and sealing testing. This platform can handle subcritical or supercritical carbon dioxide at pressures of 7–9 MPa and temperatures of 0–35°C, with the compressor outlet pressure capable of reaching over 20 MPa ； The rotor speed can reach over 40,000 r/min, with a flow rate of up to 30 kg/s ； It is capable of conducting precise and continuous testing of SCO2 compressors in the 100 kW to MW range. It is currently the only megawatt-class SCO2 compressor testing platform in China, as well as the largest and highest-grade testing platform of its kind in the world. The process flow for this testing platform was designed independently by the research institute. Since work began in May of this year, the researchers at the institute, together with external partners responsible for design, construction, and monitoring, have worked together hard. After nearly five months of effort, the project was completed to both quality and quantity standards. Through debugging and testing, the intended design objectives were achieved, and the requirements for completion were met. The laboratory is located in the entrepreneurship park of Hengshui High-Tech Zone, and leaders at all levels in Hengshui have attached great importance to and provided support for the construction of the megawatt-class SCO2 compressor testing platform. Upon the completion of the test bench, the team invited senior industry experts from within the country to conduct on-site discussions; these experts offered many suggestions and opinions regarding the operation of the test bench and compressor testing. The completion and operation of the general experimental platform for megawatt-class SCO2 compressors have put an end to the historical lack of experimental facilities for related research in China. It lays a solid foundation for in-depth research on SCO2 cycle power generation systems, and also provides experimental support for other domestic research institutions engaged in this field.