Study On Numerical Simulation With The Heat Transfer Characteristics Of SuperORV Heat Transfer Tube

With the energy crisis and environmental problems have become increasingly severe,liquefied natural gas as a clean and high calorific value energy have received much attention from the international community.In practical application,LNG needs vaporized and heated to room temperature before use.Thus LNG gasification device has become the core essential equipment in the gas industry.As a new type of Open Rack Vaporizer,Super Open Rack Vaporizer has became the most widely heating and gasification technology of LNG.The application of LNG SuperORV as the research background,and calculated the thermal physical properties of methane,obtained the graph of methane density,specific heat capacity,thermal conductivity and dynamic viscosity with temperature variation,established the physical and numerical models of SuperORV gasification segment.Using(Computational Fluid Dynamics CFD)commercial software ANYSY carried on numerical simulation the complex flow and heat transfer characteristics of supercritical pressure the LNG in SuperORV heat transfer tube.Obtain the temperature of heat transfer,inner tube fluid and wall temperature of the heat transfer tube,and the surface convective coefficient distribution of the heat transfer,analyses the inside and outside fin and spiral ties on convection heat transfer in pipe reinforcement.On the basis,this paper performance studied the operating parameters affect and the thermal heat transfer technology,analyzed the turbulent flow field distribution of low temperature LNG in heat transfer tube under the condition of Supercritical pressure and its influence on heat transfer process.The numerical simulation results show that the heat transfer tube screw disturbed flow exist obvious vertical to axial secondary flow,can largely enhance the tube fluid mixing.It has increased the strength of turbulence,weaken the effect of boundary layer.Enhanced heat transfer technology can significantly improve the heat transfer performance of SuperORV heat transfer pipe.With the increase of pressure,the mainstream average temperature of SuperORV new heat transfer pipe increases gradually as the pressure increases,when the pressure in 5MPa the heat transfer coefficient is largest,the critical pressure of methane is 4.59 MPa.Near the critical point,the heat transfer coefficient of Supercritical methane is significant increased.There is an obvious enhancement heat transfer phenomenon in the heat transfer pipe tube.With the increase of LNG flow distribution ratio,the heat transfer convection of LNG has weakened.The increase of pressure and mass flow ratio,all can lead to heat transfer reinforcement;In the area of away from plans to critical point,the heat transfer tube fluid temperature slow growth along with the increase of tube length,heat transfer coefficient of supercritical methane is also rapidly decrease.Therefore,the operating parameters such as operating pressure,mass flow ratio and other heat transfer coefficient has a great influence on the heat transfer performance.The results of the study provide technical support and theoretical basis optimize the design of the SuperORV structure and properties of the heat transfer tube.Has important academic significance and engineering application value.