Research Of Hydraulic Free Piston Engine Based On MATLAB

Hydraulic Free Piston Engine is one of the new special engines developed in the last few years. This new kind of engine is the succession and development of traditional crank rod piston engine technology. HFPE has a great application prospect with many advantages.Three basic structure types and the working principle of the hydraulic engine are introduced in the paper as well as the research status at home and abroad. Single Piston Hydraulic Free Piston Diesel Engine is selected and determined as the study object. In the premise of some basic theory like thermodynamics, fluid mechanics, dynamics, and so on,the mathematical model of all parts of the hydraulic engine was set up according to the working principle of engine components. It is the basis of the simulation model, which is set up with software MATLAB. Then the engine assembly simulation model can be obtained through the connecting and packaging technology. The innovation of the paper is to solve the problem of SHFPE, in which the piston rebounds at the lower dead center, by proposing the solution method of installing a controllable hydraulic damper at the end of the compression chamber. The simulation result shows that the scheme is effective. This way can reduce the residence time at the end of the piston movement during the expansion time and there is no rebound of piston displacement. Thus this method can improve the control of the engine,raise the power output, and provide theoretical guidance for the research of hydraulic engine.In addition, some more important factors, affecting engine economic performance, such as the load and the fuel injection timing, were simulated. The model can provide guidance for the optimal match of fuel injection quantity, injection timing and the size of the load. The result plays an important role in the practical application of the engine and its economic aspect.