Aluminum tube, mainly used in the refrigeration system of 10 ° C to -45 ° C cold storage, is the evaporator used in various food freezing and cold storage. The aluminum pipe is used for welding the copper and aluminum joints with high-frequency resistance. The aluminum pipe has a thickness of 2mm and has a pressure difference of 4.5Mpa. Aluminium discharge cooling capacity, K value ≈ 10W / (m2 · ° C) [Average], according to the cold storage design specification, Q = K · A · Δt, the temperature difference taken in the actual proportioning process Δt = 10 ° C. Considering the problem of cold storage frosting, the general low temperature aluminum storage tube is calculated according to the lower limit of 90W/M2 to prevent insufficient cooling after frosting. High temperature library without frosting can be calculated according to the upper limit of 140W/m2.