A Study On The Factors Influencing The Working Performance Of Conventional Slotted Bursting Disc

Bursting disc,as a type of precision pressure relief device,are commonly used in situations where there is a risk of overpressure,such as in pressure vessels,toxic or hazardous media storage and transportation equipment,and reactors that may experience thermal or chemical runaway reactions,due to their simple structure,sensitive response,leak-free performance,and wide range of size coverage.As most representative bursting disc,and as its stable performance and wide applicability to a wide range of diameters,the conventional slotted bursting disc is more widely used in medium and low pressure situations compared to other types of bursting discs,and the dynamic overpressure release,the testing of flow resistance coefficient,and the determination of replacement cycle of bursting discs are all urgent problems that need to be solved.In this dissertation,the conventional slotted bursting disc is taken as the research object,and a physical overpressure testing platform based on dynamic overpressure is designed.Through a combined method of numerical simulation and experimental research,the impact of dynamic overpressure and typical structural parameters on the bursting characteristic is studied.And a quantitative analysis method for the discharge characteristics and fatigue characteristics of typical radial slotted bursting discs are studied.The main research and conclusions are as follows:(1)In order to study the bursting characteristic of conventional slotted bursting disc under dynamic overpressure conditions,a physical overpressure method was proposed to achieve rapid pressure increase by controlling the opening and closing of the pneumatic ball valves.A numerical calculation model of the flow field on the dynamic overpressure test bench was established,and the pressure increase rate of the designed device was verified.Based on the dynamic overpressure test bench,the bursting performance of conventional slotted bursting disc with different diameters under dynamic overpressure conditions is studied,and the overpressure multiple was defined.The conclusion of the conventional slotted bursting disc that pressure increase rate and overpressure multiple follow a power function relationship is established.And based on the fitting equation obtained from the experimental data,a critical value of pressure boosting rate was obtained for different caliber bursting discs,which can be used as a conclusion for determining dynamic overpressure conditions.(2)The influence of the main structural parameters of conventional slotted bursting disc on bursting pressure is studied using orthogonal experimental method,including the initial thickness,stress bridge length,and number of stress bridges of three typical venting diameter bursting disc.Based on this,a dynamic numerical model of the bursting process of positive arch radial slit bursting disc under a single parameter condition is established using ABAQUS,and the variation law of bursting pressure with respect to a single parameter is studied.Based on multiple sets of bursting pressure test data with different structural parameters,a high-precision semi-empirical formula of the bursting pressure with structural parameters,including bridge length,termination hole distribution circle diameter,inner termination hole diameter,and thickness-to-diameter ratio is obtained using nonlinear regression.(3)In order to study the relationship between the characteristic parameter of bursting disc discharge-flow resistance coefficient and the opening shape of bursting discs,the opening shape of the bursting disc was parameterized using image extraction methods and the pixel ratio principle.The opening ratio of bursting discs was defined,and the relationship between opening ratio and opening angle was obtained by measuring the opening angles of bursting discs with different opening ratios.A simulation model for flow resistance coefficient of bursting discs with different opening angles based on Fluent was established,and a calculation method for flow resistance coefficient based on numerical simulation results was proposed.The influence of structural parameters of bursting discs on the opening rate of bursting discs was studied through orthogonal experiments,indicating the degree of influence of bridge length,number of bridges,and thickness on the opening rate of bursting discs.And the flow resistance coefficient of bursting discs under different opening ratios and structural parameters is also be studied,and the conclusion that the flow resistance coefficient is exponentially related to the opening ratio is obtained.It is also indicated that the initial thickness of the material has the greatest impact on the discharge performance of the conventional slotted bursting disc relative to the length and number of bridges.(4)In order to study the quantitative relationship between the fatigue characteristics and deformation variables of bursting discs,this thesis takes a typical a radial conventional slotted bursting disc as the research object.Without causing damage to the bursting disc body,high-precision laser scanning method is used to measure the deformation variables of bursting discs before and after fatigue testing.The relationship between fatigue cyclic pressure,number of cycles,deformation and fatigue life,as well as the relationship between deformation and burst pressure were studied through orthogonal experiments.The conclusion that the fatigue cyclic pressure and fatigue life follow a power function relationship,the deformation and fatigue life show a linear positive correlation,and the deformation and fatigue burst pressure follow a power function relationship are obtained.A joint simulation model based on ABAQUS and FE-SAFE for predicting the fatigue life of bursting disc is established,and the influence of bursting disc structural parameters on fatigue life was studied using numerical calculation methods.The simulation results shows that the stress concentration mainly occurred at both ends of the stress bridge,and the initial material thickness and bridge length are two important factors affecting the fatigue life of of radial conventional slotted bursting disc.