Engineering   Building

7 MPa high-pressure helium test loop

3. Major Research   Achievements

 (1)  Main Helium   Blower and Helium Compressor for the 600 MW High-Temperature Gas-Cooled   Reactor (HTGR) Nuclear Power Plant

The 600 MW commercial HTGR requires extremely high and long-term reliability and safety over   a 60-year operational lifetime. This places stringent demands on the bearing   system of the main helium blower and compressor.

To meet these requirements, the laboratory carried out   extensive R&D on several core technologies of magnetic bearings,   including active vibration suppression and control, complex rotor–bearing   system dynamics, real-time monitoring and fault diagnosis, electromagnetic   compatibility in nuclear environments, backup bearing design, and overall   system reliability.

Through comprehensive studies on small-scale test rigs   and full-scale engineering prototypes, the team systematically evaluated the   performance and reliability of key components such as magnetic bearings,   controllers, sensors, and power amplifiers. Continuous optimization,   standardized design, and process solidification enabled full mastery of the   entire magnetic bearing lifecycle - from design and manufacturing to testing and operation.

This work led to the successful localization of magnetic   bearings for the main helium blower and compressor of China’s HTGR nuclear   power plant, representing a key technological breakthrough. The achievement   was recognized in 2014 as one of the “Top Ten Scientific and Technological   Advances in Chinese Universities” by the Ministry of Education.

            600   MW HTGR main helium circulator and helium compressor

10 MW HTR-GT main helium   circulator

(2) Direct-Cycle Helium Gas   Turbine Power Generation System

In the High-Temperature   Gas-Cooled Reactor Helium Gas Turbine system (HTR-10GT), the   compressor–turbine rotor operates in a high-temperature, sealed helium   environment and must pass through two flexible critical speeds to reach its   rated speed of 15,000 rpm. Conventional mechanical bearings cannot meet the   stringent requirements of the nuclear primary circuit, which involves supporting   a large, heavy, and high-speed flexible rotor under extreme thermal and   environmental conditions. Therefore, adopting magnetic bearings was   identified as the only feasible solution.

As magnetic bearing technology   is still emerging worldwide, successful applications in large-scale   engineering systems remain rare - and no precedent existed for its use in nuclear energy systems. To   ensure safe and reliable rotor operation through multiple critical speeds,   the laboratory conducted extensive theoretical and experimental studies.

To date, only a few countries   have achieved controlled overcritical operation under laboratory conditions,   while no large-scale engineering application beyond the second flexible   critical speed had been demonstrated.

By integrating expertise in   structural design, rotor dynamics, system identification, automatic control,   sensing, and power electronics, the laboratory successfully overcame the   challenge of achieving stable and controllable operation beyond the second   critical speed, completing the design and prototype development of the helium   gas turbine magnetic bearing system.