Winding Process Analysis And Mechanism Design Of Hydrogen Cylinder

Hydrogen energy is a kind of zero carbon energy with high combustion value,and the combustion products are only water and heat.Therefore,it is regarded as the most potential clean energy.With the maturity of hydrogen energy technology,the application scenario of on-board hydrogen cylinders is also gradually expanding.At present,the hydrogen cylinders on the market are mainly type III hydrogen cylinders composed of metal lining and outer composite winding layer.In order to achieve the goal of lightweight and high hydrogen storage density,a large number of scholars at home and abroad have made research on type IV plastic lined hydrogen cylinders.At present,the United States and some European countries have successfully developed type IV hydrogen cylinders with working pressure of 70 MPa.However,due to the complex structure and process of such cylinders and certain technical blockade,there is still a gap between domestic research and these countries.In this paper,the winding process and winding mechanism of 70 MPa type IV hydrogen cylinder are studied:（1）The hydrogen cylinder is composed of plastic liner and composite winding layer.Because the liner of the cylinder determines the winding line,it is easy to cause the instability of the liner due to the winding tension in the winding process.Therefore,this paper first carries out the liner design and stability analysis of the hydrogen cylinder.By comparing the advantages and disadvantages of different forms of heads,elliptical heads are selected;According to the load requirements,the mechanism of head nozzle is designed;In order to meet the process requirements of stable winding,the tangent point method is used to design the line type of gas cylinder.Combined with the formula of core mold angle and volume of gas cylinder,the relationship function between cylinder diameter and core mold angle is deduced,and the appropriate winding line type is selected to obtain the size of gas cylinder;The eigenvalue buckling analysis and post buckling analysis of the lining are carried out by using Abaqus software,and the buckling load of the lining is obtained.Compared with the compressive stress of the winding fiber on the lining,it is judged whether it is necessary to rush a certain pressure of hydrogen into the lining to prevent the buckling deformation of the lining.（2）The winding layer of hydrogen cylinder is designed and improved according to the design requirements.Firstly,the thickness of spiral winding layer and circumferential winding layer of gas cylinder is calculated by using grid theory,and the preliminary winding layer scheme is obtained;Cubic spline curve is used to predict the thickness at the head to provide data for accurate modeling of gas cylinders;Finally,the pressure and stress of the cylinder are analyzed by Abaqus finite element method;Because the grid theory is only a preliminary design theory,this paper improves the winding layer by referring to the improved theory of other scholars for the winding layer of gas cylinder,and determines a better winding scheme through finite element analysis to make the gas cylinder meet the design pressure requirements.（3）A gantry type hydrogen cylinder winding machine is designed.By studying the principle of winding machine,the tail seat,beam,spindle box,trolley and other mechanisms of winding machine are designed.When designing the base and cross beam,the finite element analysis software is used to analyze the design scheme.The results show that adding stiffeners above the cross beam can effectively improve the bending strength of the cross beam,and the scheme of using internal welded support plate on the base can increase the stiffness of the base and improve the stability of the winding machine;According to the motion requirements of multi station winding machine,the spindle box and tailstock adopt a driving shaft to drive the transmission system of two driven shafts.In order to wind cylinders of different sizes,the tailstock is designed as a structure that can move relative to the base;The transverse motion of the trolley is driven by gear rack,and the longitudinal motion is driven by lead screw mechanism.The turnover mechanism is a transmission mode in which one motor drives three wire winding nozzles to rotate at the same time through belt transmission;A tension control mechanism is set between the yarn frame and the trolley,the magnetic particle clutch is used to apply friction,and the tension of the winding fiber is detected in real time through two fixed rollers and a pressure roller connected with the parallel beam load cell;The threedimensional modeling of winding machine is carried out by using Solid Works.In this paper,the winding process of 70 MPa type IV hydrogen cylinder is theoretically analyzed,and the mechanism of hydrogen cylinder winding machine is designed.The purpose is to provide reference for the experiment and production process and lay a theoretical foundation for the development of hydrogen cylinders.