The pressure drop and heat transfer characteristics of condensation flow with hydrocarbon mixtures in a spiral pipe under static and heaving conditions

A model based on ASNYS CFX was established to explore the pressure drop and heat transfer characteristics of condensation flow with hydrocarbon mixtures in a spiral pipe under static and heaving conditions, whose deviations are within ±15% compared to experimental ones. It considered the effects of motion parameters, operating parameters and structural parameters on frictional pressure drop and heat transfer coefficient for three hydrocarbon mixtures. The ranges of mass flux, vapor quality, heat flux, saturation pressure, hydraulic diameter, curvature diameter and inclination angle were 200–800 kg/(m²·s), 0.3–0.9, 10–20 kW/m², 2–4 MPa, 6–14 mm, 1.6–2.4 m and 6–14°, respectively. The results demonstrate that methane/ethane mixture has the best heat transfer and the smallest pressure drop among three mixtures. At static condition, as the vapor quality and mass flux increase and the saturation pressure and hydraulic diameter decrease, there are evident increases in heat transfer and pressure drop, whereas the impacts of curvature diameter, inclination angle and heat flux on them are insignificant. Meanwhile, the heaving motion affects pressure drop and heat transfer and makes it show better overall heat transfer performances, where the comprehensive heat transfer factors (CHFs) of 83.33% data points are more than 1. Further, the heaving effects increase with the increasing heaving amplitude and the decreasing heaving cycle.