Hydrogen Permeability of PdY Alloy Tube Bundle

PdY alloy membranes are expected to be used in fusion reactor hydrogen isotope purification processes due to their good hydrogen permeability and mechanical properties. Based on the service parameters and tritium safety requirements of PdY alloy membrane, it is necessary to study the hydrogen isotope permeation characteristics of PdY alloy membrane under low hydrogen pressure, so as to provide data support for the subsequent design of hydrogen isotope purification module. In this paper, based on the straight tube external pressure PdY diffuser, the influence of pressure and working temperature on hydrogen permeation rate of 80 μm thick PdY alloy membrane tube with low hydrogen pressure(<50 kPa) and working temperature of 350-450 ℃ was studied. The results show that under low hydrogen pressure, the hydrogen permeation of PdY alloy membrane conforms to the rule of J=Φpⁿ_H-pⁿ_Ld. When the pressure index n is equal to 0.9, the permeation rate control mechanism is mainly the surface velocity control step; increasing the working temperature makes the permeation flux increase, and the influence of temperature on the diffusion process is greater, so that the permeation process tends to be surface controlled. In addition, the permeability coefficient under the working temperature range is calculated and analyzed, and the permeation activation energy is about 24.54 kJ/mol and the permeability constant Φ₀ is 5.86×10^-6 mol/(m·s·kPa^0.9) through the Arrhenius formula. Under low hydrogen pressure, the permeability coefficient of this thickness membrane can be calculated by 5.86×10^-6e^-24.54/^(RT) mol/(m·s·kPa^0.9).