Briefs: Thermoacoustics

A project led by the University of Nottingham aims at developing a device acting as a refrigerator, cooker and power generator, using biomass fuels such as wood. The SCORE (Stove for COoking, Refrigeration and Electricity) is based on the use of thermoacoustics, which uses the generation of sound waves when gas is unevenly heated. These pressure sound waves can operate mechanical motion, as in a Stirling engine, but they can also be used to pump heat when emitted through an inert gas such as nitrogen or helium, with the aid of a heat exchanger. This process can go on uninterruptedly as the sound waves alternately cool and heat the gas in the heat exchanger and is definitely a more efficient and healthier way of using wood as fuel than the traditional open fire. The SCORE team aims at producing these devices in significant numbers within 5 years. Thermoacoustic engines and refrigeration units have been used before in high-tech settings, as power sources or cooling units on spacecraft, satellites and military applications for example, but have been limited to these top end applications until now. However, as thermoacoustic technology is rather simple and cheap, it is to be hoped that this device may benefit many people in rural areas in developing countries.