Refrigerator Control Methods and Heat Exchanger Operating Condition for the CNS

The Cold Neutron Research Facility (CNRF) project had been embarked in the middle of 2003 in HANARO. The Cold Neutron Source (CNS) facility, one of the main parts of the CNRF project, includes the In-Pool Assembly (IPA) and related systems to moderate thermal neutrons through liquid hydrogen, moderator, into cold neutrons with the generation of the nuclear heat load. Since proper removal of the heat load is of significant to keep the desired liquid level in the moderator cell, the heat exchanger should be designed to meet its required thermal performance and the helium refrigeration system (HRS) should be controlled corresponding with the variable heat load dependent on the CNS operation mode. This paper describes the design specification of the heat exchanger and the conceptual control methods of the HRS