Preliminary Tests for the HTR-10 Helium Circulator with the Active Magnetic Bearings

The Helium circulator is one of the key equipment of the high temperature gas-cooled reactor (HTR), which directs helium to flow through the reactor core and the steam generator to achieve the thermal energy transfer between them. At present, there are two optional schemes in the design of the helium circulator. One is the dry gas seal, another is the active magnetic bearing (AMB), but both of them haven’t been used in the reactors beforetime. After the 10 MW High Temperature Gas-cooled Reactor-Test Module (HTR-10) was brought to criticality in December of 2000, Institute of Nuclear and New Energy Technologies (INET) of Tsinghua University dedicated to upgrade the technology of the helium circulator. It takes 3 years to manufacture a helium circulator with the active magnetic bearings in Shanghai Blower Factory, which has the same rated parameters as the one of HTR-10. It stood all the tests in November of 2007, including the 100 hour test at the conditions of high temperature(250°C) and high speed (5000r/min). All of these means INET made a great progress in the area of the active magnetic bearing technology. This circulator will be installed to HTR-10 to endure the further tests at the reactor conditions such as high temperature, radiation, graphite dust and the inert helium atmosphere. In the foundation of these successful tests, the design of the larger scale and higher power level helium circulator with AMBs for the HTR-PM project will enter the official implementation stage. This paper covers the philosophy behind the design and descriptions of the HTR-10 helium circulator and the preliminary tests. Significantly useful information is also derived from temperature distribution in the AMBs.