Technology Research On Strengthening Nature Gas Hydrate Formation By Pipe Spiral Flow

Research on strengthen generation of natural gas hydrate is the hot spot of the hydrate application, which are widely used in the oil and gas transportation, petrochemical, energy chemical and environmental engineering, and so on. Looking for a new way in strengthening generation of natural gas hydrate and making systems research can optimize the existing operation and design more efficient new hydrate reactors, and can be based on developing the oil and gas pipeline transportation and energy environment. A new type equipment of spiral flow strengthen generating hydrate was developed, which was based on characteristics of existing hydrate formation device. The gas-liquid two-phase spiral flow and hydrate formation in the piping system were researched by the experimental way, and mainly includes:The domestic and foreign present situation on the natural gas hydrate exploration and mining was concluded, and the domestic and foreign methods of strengthening generation gas hydrate were mainly researched, which included physical and chemical methods. The advantages and disadvantages of various reinforcement methods and the difficulty of present industrial mass generation natural gas hydrate were detailed analysis. The way of spiral pipe flow developing natural gas hydrate formation technology was a new efficient type of gas hydrate generation device.The experimental investigation on gas-liquid two-phase spiral flow in way of vane was conducted. The flow patterns of gas-liquid two-phase spiral flow in way of vane were described and defined, and the flow map was drawn. The influence of the velocity on flow pattern and effect of vane parameters on flow convection boundary were investigated. The influence of gas volume fraction, flow pattern, flow velocity and vane parameters on the pressure drop were studied. Then, the experimental study was conducted to get more insight into the flow characteristics of single phase spiral flow in the horizontal pipe by the use of a Laser Doppler Velocimeter (LDV). Influence of flow attenuation, average Reynolds number, spiral angle and vane area on axial velocity distribution and tangential velocity distribution were studied. Turbulence intensity distribution was studied, and the spiral strength attenuation law was analyzed. The gas-liquid two-phase spiral flow patterns were researched in the horizontal pipe with the twist tape, and the four new flow patterns were obtained, and the influence of twist rate on flow convection boundary and pressure drop were investigated. The research on gas-liquid two-phase spiral flow in a horizontal pipe laid a foundation on spiral pipe flow hydrate formation.The experimental study on the pipe flows reinforce natural gas hydrate formation was investigated. The characteristics of hydrate formation in pipeline were studied, and the induction time and the generation time of hydrate formation with different velocity and different twist rate were studied. The effect of temperature and twist rate on hydrate formation was investigated, and the gas consumption was studied. The hydrate formation mechanism in the pipe was summarized in primary, and hydrate formation kinetics model in consideration of promoter in the pipe was established.