Development of Liquid Piston Stirling Engine

Abstract

Stirling engines are a type of reciprocating external combustion engines that use one or more pistons to achieve useful work through some input of heat from an external source. The liquid piston heat engine, also known as the Fluidyne design, utilizes liquid water as pistons that are enclosed in a cylinder which entraps a working gas. Stirling engines are low efficiency engines that can utilize waste and low-grade thermal energy to pump water at a small scale. Exploiting these low-grade waste and renewable energies provides significant opportunities for addressing the energy related problems, such as energy safety and shortage, greenhouse gas emission, water dissipation, etc. Due to the great capability of recovering low-grade heat with potentially high efficiencies, Stirling cycle engines have attracted increasing attention in recent decades. Due to their low power density and efficiency use of fluidyne pumps at a small scale may be very useful. Liquid pistons avoid the sliding mechanical seal and accurately dimensioned cylinders, which provide great flexibility mechanical design with much simpler constructions. With the implementation of fluidyne pumps both the requirements efficient utilization of energy sources and a shift to renewable resources are fulfilled. This research will raise awareness for the neglected way of using renewable source to pump water especially the use of biomass. The research will also cover that what effects are observed when in a fluidyne engine the water levels are changed and the effect of using a mixture of different working liquids of low heats of vaporization