Numerical simulation of convective heat transfer of supercritical methane in a horizontal tube

In order to study the supercritical liquefied natural gas( LNG) heat transfer characteristics in tubes,methane is used herein to replace LNG to investigate the numerical simulation of convective heat transfer of supercritical methane in a horizontal tube. The heat transfer characteristics of methane under supercritical pressure is found out by changing the inlet velocity,wall temperature of the tube and pressure. The results show that the surface heat transfer coefficient has a peak value at the critical point,which demonstrates that it is beneficial to heat transfer under supercritical condition. The influence of inlet velocity on the heat transfer coefficient is significant,the surface heat transfer coefficient increases with the increase of inlet velocity. The wall temperature has a little influence on the heat transfer coefficient; with the increase of wall temperature,the heat transfer coefficient decreases slightly. The influence of pressure on the heat transfer coefficient is related to critical temperature. When the fluid temperature is below the critical temperature,the surface heat transfer coefficient decreases with the increase of pressure,but when the temperature is higher than the critical temperature,the heat transfer coefficient increases with the increase of pressure.