On June 18, the "Sodium-supercritical carbon dioxide heat exchanger development and test project" in the key technology research of the fourth-generation nuclear energy system sodium-cooled fast reactor passed the acceptance of the expert group. This marks the successful development of my country's first high-efficiency and compact sodium-supercritical carbon dioxide printed circuit board heat exchanger, and has made a major breakthrough in the field of innovative power conversion technology in the fourth-generation nuclear energy system, liquid metal cooling fast reactor. At present, my country has fully mastered the design, manufacturing and testing technology of sodium-supercritical carbon dioxide heat exchangers, and has reached international advanced level in this field, laying a solid foundation for the subsequent realization of industrial applications.
In order to meet the high economic and safety requirements of the fourth-generation advanced nuclear energy system, since 2016, with the support of the Ministry of Science and Technology, the Nuclear Institute of China National Nuclear Corporation has launched the key technology of sodium-cooled fast reactor based on supercritical carbon dioxide power cycle technology. the study.
Carbon dioxide in supercritical state is one of the most advanced thermal engine circulating working fluids in the world. It has the characteristics of high cycle efficiency and small equipment volume. It can reduce the number of equipment, reduce construction and maintenance costs, and significantly improve the economy. The application prospect is currently the frontier and hot spot of domestic and foreign research. In addition, since carbon dioxide does not react violently with liquid metal sodium, it has a self-suppression mechanism even in emergencies, which can automatically slow down the consequences of the accident and significantly improve the safety of sodium-cooled fast reactors.
Sodium-supercritical carbon dioxide heat exchanger, as one of the key equipment in the circulation system, needs to achieve high-efficiency heat exchange under harsh conditions such as high temperature, high pressure and strong corrosion. The printed circuit board heat exchanger is a compact and efficient heat exchanger product, which has the dual advantages of shell and tube heat exchanger and plate heat exchanger.
In 2019, the Atomic Energy Agency and China Shipbuilding Heavy Industry 725 developed a high-efficiency and compact sodium-supercritical carbon dioxide printed circuit board heat exchanger prototype, and jointly designed and built a sodium-supercritical carbon dioxide thermal hydraulic test device with Hanhua Jingdian, The heat transfer performance experiment of sodium-supercritical carbon dioxide heat exchanger was carried out.
In December 2019, the prototype of sodium-carbon dioxide heat exchanger was completed. In May this year, the heat transfer performance experiment was completed, and important parameters such as heat transfer power and temperature distribution were in good agreement with the design. In addition to the sodium-cooled fast reactor, the heat exchanger technology can also be used in the power conversion system of other liquid metal cooling reactors such as lead-bismuth alloy, sodium-potassium alloy, etc. It has a broad application prospect.