Numerical simulation on gas-liquid two phase flow in the U-type pipe

Abstract An effective way to improve the formation of gas hydrate is to increase the gas-liquid contact area, which can also improve the gas-liquid heat and mass transfer efficiency. Designed a natural gas hydrate formation flow experimental device, and a set of folding pipes are the gas hydrate formation units. The folding pipe hydrate formation units are composed of many U-type pipes, which are the main carrier of hydrate formation. The gas-liquid flow law in the U-type pipe has the great significance on gas hydrate formation. The gas-liquid two phase flow in a single U-type pipe has been simulated by Fluent, gas distribution rule and flow characteristics in the U-type pipe has been investigated. The range of the entrance gas volume fraction is 0.1～0.6. Calculation results show that there is a certain degree of mixture between gas and liquid in the former straight section. The gas and liquid began to layer in the front of bend, the gas and liquid stratified obviously in the process of bend. The gas and liquid began to mix in the later straight section, but the degree of mixture is lower than the former. The liquid and gas flow phenomenon is different with disparate gas volume fraction. The gas and liquid stratified more obviously in the bend with the higher gas volume fraction. The law that the gas and liquid have a better mixture when gas volume fraction change range is 0.2～0.4 has been found, which is beneficial to hydrate formation.