FREE PISTON HYDRAULIC ENERGY GENERATOR USING THE STIRLING ENGINE PRINCIPLE

Abstract

Reducing fuel consumption for vehicles is not only necessary to save energy, but also for drastic reduction of polluting emissions, and for changing the transport system to be more economical and less pollutant. Hydraulic hybrid systems have the advantage of high power density and the system of recovering the braking energy is able to work at high frequencies of loading/unloading conditions. Nowadays it is known that investigations are made to increase hydraulic efficiency, for example pumps and hydraulic motors with distribution controlled electronic, whose efficiency is 95%. Another direction is the primary source of hydraulic energy. A solution is using a free piston Stirling engine. In comparison with the free piston Stirling engines, classical Stirling engines are complex, with a need for lubrication, seals and bearings that combined reduces the performance and limits the endurance of the engine. The power produced by the classical Stirling engine is hard to be used for hybrid hydraulic propulsion. This paper describes simulation results of a free piston Stirling engine that generates the hydraulic energy needed by a hydraulic – hybrid vehicle propulsion. The system analyzed in this paper is a free piston Stirling engine.