STIRLING ENGINE WITH FRESNEL LENS FOR POWER GENERATION

INTRODUCTION

              A Stirling engine is a heat engine operating by cyclic compression and expansion of air or other gas, the working fluid, at different temperature levels such that there is a net conversion of heat energy to mechanical work. The cycle is reversible, meaning that if supplied with mechanical power, it can function as a heat pump for heating or cooling, and even for cryogenic cooling.

           The cycle is defined as a closed regenerative cycle with a gaseous working fluid. "Closed cycle" means the working fluid is permanently contained within the thermodynamic system. This also categorizes the engine device as an external heat engine. "Regenerative" refers to the use of an internal heat exchanger called a regenerator which increases the device's thermal efficiency.

            Solar energy is used to heating the input air of the cylinder. The Fresnel lens are focused the solar rays into the hot end cylinder air. So the air pressure is increased and expands the piston to produce mechanical energy. This process is cyclic and the power producing is continuously.

ADVANTAGES

Ø  They can be built to run quietly and without an air supply & they start easily (albeit slowly, after warm up)

Ø  Stirling engines can run directly on any available heat source

Ø  Waste heat is easily harvested

DISADVANTAGES

Ø  Typically these material requirements substantially increase the cost of the engine.

                             

Ø  A Stirling engine cannot start instantly; it literally needs to "warm up". This is true of all external combustion engines.

APPLICATIONS

Ø  It is probably there that the Stirling engine will develop more power & this will be a way to

  make electricity, heating of home and to produce domestic hot water.

Ø  The residential electric power represents now about 8% of total production.