Investigation and development on performance of a rice-husk powered Stirling engine-generator

Abstract

In few decades, modern Stirling engines were vastly developed and applied as cogeneration systems with high performance and efficiency. The principal advantages of the Stirling engine, external heating and high efficiency, make this engine of the bright future in sustainable energy. Because of the simplicity of its design, the Stirling engine can be manufactured as an inexpensive power source for electricity generation using biomass fuels with low noise and emission, efficient, and environment security. Accordingly, there are many research works of Stirling engine presented and commercial Stirling engines produced as alternative engines for renewable energy. However, power produced by Stirling engine using air as a working gas is usually inefficient and low in power. To increase power and efficiency of the engine, hence, dynamic balance and efficient heat transfer are the key factors. This project aims to present the investigation and development of a few horse power practical Stirling engine-generator using rice husk as biomass fuel. The engine is the betatype feature with rhombic drive mechanism using air as a working gas. Rhombic drive mechanism is designed for engine balance of a single acting engine. A rice husk burner system and heat exchanger configurations of the engine were proposed. A proof-of-concept engine has been built with swept volume of 110 cm3 and tested. The testing results showed that the unpressurized engine started operation in only about 100 seconds at the heater temperature of 460°C with 312 rpm. At the heater temperature of 540°C, the engine speed was 680 rpm. At the engine speed of 280 rpm, the maximum torque was 0.245 Nm while the maximum power was 7.85 W at 360 rpm. The practical prototype is being manufactured with swept volume of 7,000 cm3 and tested to achieve a few horse powers. The engine performance is continuing measured and improved. © 2012 by the American Institute of Aeronautics and Astronautics, Inc.