关键词: 传热, 两相流, 蒸发, 流动沸腾, 液化天然气

Abstract: An experimental apparatus was set up for study on the heat transfer characteristics of liquefied natural gas (LNG) flow boiling in a vertical smooth tube with 8 mm inner diameter. The experiments were performed at pressure of 0.5 MPa, with mass fluxes from 50 to 200 kg·m^-2·s^-1 and heat fluxes from 8.0 to 36.0 kW·m^-2. The influences of quality, heat flux and mass flux on the heat transfer characteristics were examined and discussed. The results show that the mass flux has a strong effect on the heat transfer coefficient of LNG. The heat transfer coefficient increases with the mass flux. It also increases with the heat flux when the vapor quality is low. This phenomenon is more noticeable at low mass flux. When the vapor quality is lower than 0.5□6, the heat transfer coefficient increases with the quality; when the quality is higher, the heat transfer coefficient decreases. The experimental heat transfer coefficients were compared with predicted values by four existing correlations. The correlation of Zou et al. gives the best prediction with the deviation of ±30.2%.

Key words: heat transfer, two-phase flow, evaporation, flow boiling, liquefied natural gas