Stirling Engine
The first Stirling engine in Iran was designed and built in 1978 by the late professor Dr. Jafar Zarrin Chang at Shiraz University. He also published a large number of books and journal papers on the subject of Stirling engines. He is called father of Iran’s striling engine.
The Stirling engine was invented in 1816 by the Scottish clergyman Robert Stirling. Stirling engine is a heat engine that is operated by the cyclic compression and expansion gas at different temperatures, resulting in a net conversion of heat energy to mechanical work.
Stirling Engines
Stirling Engines are divided into four main categories:
- Alpha
- Beta
- Gamma
- Free piston
The main applications of these engines are in the power generation of water pumps, submarines, medical equipment’s, refrigerators and spacecraft.
Concentrated solar energy, geothermal energy, nuclear energy, waste heat and bioenergy (agricultural waste) can be heat sources for Stirling engines.
In the diagram opposite, the percentage of possibility of using different energies has been determined. It can be realized that all the factors are available to take advantage of using solar energy as a heat source for Stirling engines.
Advantages of using Stirling engines
Stirling engines provide many advantages over other techniques. for example, different types of fuel can be used in this technology with negligible noise & vibration and very low emissions.
According to the definition of thermal efficiency of thermodynamic cycles, the Stirling cycle has the highest efficiency after the Carnot cycle, which extracts the maximum amount of work theoretically possible from a heat source. Due to the lack of combustion in the internal chamber, the very low friction of the engines is very low, resulting in longer component life and reduced engine maintenance costs. The worst case does not exceed 45 decibels, which is less than the minimum noise pollution of conventional internal combustion engines.
Due to the wide range of available energy sources such as the sun, waste heat of wood waste, nuclear energy, fossil fuels, waste heat and geothermal, stirling engines don’t have the problems of single-source engines or with limited energy sources.