Numerical and experimental investigation of the coupled heat transfer in cold box

Radiative Discrete Ordinate (DO) model and gas conduction model are firstly applied to simulate the coupled heat transfer with radiation and conduction in a cold box of Cold Neutron Source (CNS) device. An experiment rig is conducted under the similar conditions to validate the simulation models. Results indicate that the total cold loss from the coupled heat transfer can be decreased effectively by adding the thermal insulation shield. For one shield, the total cold loss increases with the increase of the distance between shield and internal cavity at low pressure range (Lt 10^-2 Pa). In contrast, at high pressure, the total cold loss decreases as the distance increases. These conclusions may be useful to study the thermal insulation and the optimum design of low temperature cold box.