The Mathematical Model and Simulation Analysis of Piston Accumulator

摘要

The energy in the sea is rich,ocean energy generation is the new direction of the renewable energy utilization.But the working conditions at sea are mutative,the most important problem on ocean energy generation is how to guarantee the output power stability.At present,the common second conversion device is the hydraulic system,which can transform the unstable ocean energy into stable hydraulic energy,in order to generate stable electricity.The accumulator in hydraulic system is the most important part in absorbing the pressure pulsation.Therefore,it is necessary for us to make a research on mathematical model,dynamic performance and simulation analysis of accumulator.At present,accumulators are often used in hydraulic system,there are many kinds of hydraulic accumulators,hydraulic bladder accumulator and pistontype accumulator are commonly used in the hydraulic system.They are often used to be auxiliary power source,absorb the hydraulic shock,reduce the pressure pulsation,and so on.This article is based on the mechanical model of piston-type accumulator,and it uses the united simulation technique of MATLAB and LABVIEW to get the visualization of the results,at the same time,it uses SIMULINK to make the simulation analysis.We take the two conditions to make simulation analysis,including the same standard,working pressure,different gas pressures and the same working pressure,gas pressure,different standards.And we get that,when we do not consider the effect of connecting pipes,inlet valve,and nonlinear factors of accumulator itself,the mathematical model of piston accumulator is second-order oscillator model.In fact,when the damping ratio is 0.707 and the natual frequency is close to the pulse frequency of system,it can get the best absorption pulse effect.And the main factors to affect damping ratio and natual frequency are system conditions,the structural parameters and working parameters.The working conditions at sea are mutative,according to the system conditions,when we slect the suitable structural parameters and working parameters in order to make the damping ratio and the natual frequency get the suitable values,then we can get stable electricity.We propose a performance optimization plan of piston accumulator,at the same time,making a good reference on selecting accumulator for stable ocean energy generation.