Thermodynamic analysis of structural parameters during condensation in spiral tubes

•The experimental system and model of condensation in spiral tube are established.•The effects of structural parameters on condensation characteristics are studied.•The enhancement factor of spiral tubes with different parameters are compared.•Compared with the helix angle and spiral diameter, the effect of inner diameter is momentous.•To provide guidance for the design of large-scale LNG spiral wound heat exchanger. In this paper, a two-phase flow experimental system is proposed based on the condensation flow of the hydrocarbon mixture in the spirally wound tube to study the characteristics of the mixture (methane/ ethane/propane) in the spiral tube. An investigation is conducted on the effects of spiral diameter (D), inner diameter (d) and helix angle (β) on heat transfer coefficient (hmix) and friction pressure drop (ΔPfric). Moreover, the performance evaluation criterion (PEC) is adopted to measure the effect of structural parameters. As indicated by this paper, hmix decreases with the increase in β, d and D, whereas ΔPfric changes more significantly with d. If d increases or β decrease properly, the PEC will increase, which is of high significance to the design of tube-wound heat exchangers. The results of this paper can provide a reference for investigating the mechanism of condensation heat transfer in spiral tubes and the design of spiral wound heat exchangers.