Study of Optimum Operating Condition for the Helium Refrigeration System of the LHD with a Dummy Load Apparatus

Publisher Summary A dummy heat load experimental apparatus is developed to test a refrigeration system of the Large Helical Device (LHD). It establishes a full automatic operating scenario of the helium refrigeration system for the LHD. The apparatus primarily consists of a forced-flow low temperature helium line, a liquid helium supply line and a liquid helium bath. The helium refrigeration system is operated with three refrigeration modes under steady-state condition. It is confirmed that the refrigeration system maintain reliable operation with a dummy load apparatus. However, the system is not fully satisfied its full-automatic operating mode. In other words, control valves of the refrigerator or liquefier are required some adjustment by an operator while operating with various refrigeration modes. Additional experiments are still necessary to establish full-automatic condition of the refrigeration system.