Speaker
Description
China Spallation Neutron Source(CSNS) cryogenic system provides supercritical cryogenic hydrogen to neutron moderator, including a helium refrigerator, hydrogen loop and the hydrogen safety system. The helium refrigerator is provided by linde with cooling capacity of 2200W at 20 K. Hydrogen loop mainly includes hydrogen circulator, ortho-para convertor, helium-hydrogen heatexchanger, hydrogen heater and accumulator. These equipments are integrated in hydrogen circulation cold box and accumulator cold box. Hydrogen safety system includes safety valve, rupture disk, hydrogen sensor, and other equipments to ensure that cryogenic system in dangerous situations will goes down, vents or takes other measures. At present, all the equipments have been installed, and neutron moderator will be connected in the near future. To verify the cryogenic system accords with the design requirements, we use the heater instead of neutron moderator for commissioning. First, in the case of using helium, cryogenic system cooled to 20K, then stop and leak detection. Second, in the case of using hydrogen cooled down to 20K, optimizing the control logic. After the completion of the cryogenic system commissioning, the next step is cryogenic system connecting with moderator for commissioning, in the case of helium and hydrogen, and the last step is CSNS joint commissioning.