Stirling Heat Engine, Peltier Device, and Iceland
The Stirling engine, which is known for its high efficiency, is a machine that uses heat energy to generate power. Rev. Robert Stirling invented it in 1816 because he was looking for an alternative energy source that was safer than steam. A Stirling engine works in a four-step process, compressing cold gas, heating the gas, expanding the hot gas, and cooling the gas. This process is repeated over and over again. One of the positive effects of this type of engine is that it doesn’t generate any emissions. One of the unique features of this type of engine is the fact that it is a closed cycle, external combustion engine. This means that it uses a fixed amount of fluid to run and other gases can also be used. This feature allows the engine to run on any kind of fuel such as solar, nuclear, or biological waste. There are many different types and versions of Stirling engines and they mostly differ in the number of cylinders they use to generate power. One of the downsides of this type of energy is the fact that it is large for the power that it produces which limits the range of uses to low power application. However, specific power can be improved by use of higher gas pressures.
Peltier devices, also known as thermoelectric coolers, use the Peltier effect to move heat. These devices typically produce heat from 40C to 70C. Some of the more developed versions of these devices can also transfer heat from one place to another. The concept of Peltier effect goes back to 1834. All electric current is supplemented by heat current based on the Joule heating theory, Peltier realized that when electric current passes across the junction of two dissimilar conductors, there is a heating effect that is not based solely on Joule hearting.
When two conductors come to electric contact, electrons move from the one where electrons are less bound to the one with more electrons. The reason behind this difference is the Fermi level between the two conductors. When two conductors with different Fermi levels make contact, electrons flow from the conductor with the higher level of electrons until the two conductors stabilize in value. In other words, it brings heat from one side to the other side while one side gets cooler and the other side gets hotter with the consumption of electric energy. The current passing across the junction can result in a temperature incline. This type of device can be used for both heating and cooling and can also be used as a temperature controller. This device has the same disadvantage of the previous device in a way that it has high costs with low energy production.
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http://www.mpoweruk.com/stirling_engine.htm.
Japan Steel Buys Stake in Icelandic Geothermal Power Venture — Alexander’s Gas and
Oil Connections. N.p., n.d. Nov. 2015.
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