Research On The Shell-side Falling Film Thermal Performances Of Spiral-wound FLNG Heat Exchangers

Spiral-wound heat exchanger(SWHE)is one of core equipment of FLNG,flow and heat transfer process of heat exchanger become complex when it is under sea wind,sea waves and other external condition.This paper simulates falling film heat transfer performance of spiral-wound heat exchangers at calm and sloshing condition.On this basis,construct experimental device and study the influence of heat exchanger under different sloshing condition.This paper construct a three dimentional physical model of spiral-wound heat exchangers,simulate the thermal performance of heat exchangers with different winding angle,longitudinal distance between tube and outside tube diameter by using VOF multi-phase model,evaporation and condensation model and CSF surface tension model.On this basis,this paper researchs the thermal performance under sloshing condition by compiling UDF and using moving mesh method.In addition,this paper carried on the LNG cryogenic liquid dynamic experiment,analyzed the thermal performance of SWHE under different sloshing condition,such as pitch,yaw,surge,heave and tilt.The study shows that the shell-side heat transfer coefficient of SWHE decreases with the increase of winding angle and longitudinal distance between tube,increase with the increase of ouside tube diameter.When sloshing condition certain,the shell-side heat transfer coefficient of SWHE decreases with the increase of winding angle and longitudinal distance between tube,increase with the increase of ouside tube diameter.When structure paramer certain,the shell-side heat transfer coefficient of SWHE decrease with the increase of sloshing angle,increase with the increase of sloshing cycle.Summarize the empirical correlations of shell-side heat transfer coefficient under static state.The experimental result shows that pressure drop,temperature and UA value are relatively uniform and present periodic wave under different sloshing conditions.The shell-side UA value decreases with the increase of sloshing range,increase with the increase of sloshing cycle.Pitch has the biggest effect for SWHE,tilt and yaw take the second place,surge and heave have the minimal impact.On this basis,summarize the empirical equations for different sloshing condition and provide effective advice and guidance for the operation of the sea around the SWHE.