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The Barton Evaporation Engine (BEE) is a heat engine invented in 2004 by Dr Noel Barton of Sunoba Pty Ltd. The concept is patented in Australia (Australian patent 2007240126). ==Principle== The evaporation engine works by evaporative cooling of dry air at reduced pressure. Key steps are: (1) adiabatic expansion of unsaturated air; (2) evaporative cooling at reduced pressure; and (3) re-compression back to atmospheric pressure with further evaporation. Net work is available in the cycle, so the engine produces power and cooled moist air from water and hot dry air: : hot dry air + water → power + cooled moist air The remarkable property of the evaporation engine is that the temperature of an air stream is reduced at the same time that power is produced. This occurs without violation of the 2nd Law of Thermodynamics because the entropy increase as water is evaporated outweighs the entropy decrease as the air cools. With a modest amount of passive solar pre-heating, the engine theoretically is able to produce power in hot arid climates. As well as being a heat engine, the evaporation engine can also be used as an evaporative cooler. The evaporation engine has broadly comparable theoretical efficiency to simple Rankine steam turbines, without need for high-pressure boiler or condenser. The evaporation engine can function well on industrial waste heat, particularly the exhaust gas of open-cycle gas turbines. The thermodynamic cycle can be achieved by at least three separate mechanisms. The most straightforward mechanism is a piston-cylinder device, for which a full thermodynamic analysis was published in 2008.〔N.G. Barton, “An Evaporation Heat Engine and Condensation Heat Pump”, ANZIAM J, Vol 49 (2008), 503-524.〕 Barton also built an experimental piston-cylinder engine.〔N.G. Barton, “Experimental Results for a Heat Engine Powered by Evaporative Cooling of Hot Air at Reduced Pressure”, Proc ANZSES Conf, Sydney (2008).〕 that provided confirmation of the theory. As a second option, the evaporation engine can also be configured in continuous-flow form, for which a full analysis was published in 2012.〔N.G. Barton, “The Expansion-Cycle Evaporation Turbine”, J Eng Gas Turbines and Power, 134 (2012), 051702.1-051702.7.〕 There is a third possible manifestation based on the Bernoulli effect for compressible gases. As a compressible gas flows through a narrow orifice, the pressure and temperature decrease, thereby allowing the possibility of evaporative cooling at reduced pressure in the high-speed section. On recovery to slow speeds, there will be surplus pressure that can drive a turbine. Barton has also analyzed this mechanism. The analysis has not been published but is available on request to Sunoba Pty Ltd.〔N.G. Barton, “A Heat Engine and Heat Pump based on the Bernoulli Effect”, 18 pp, Sunoba Pty Ltd (2006).〕 The Bernoulli turbine would face extreme (perhaps insurmountable) difficulties in construction, much more so than with the other two versions. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Barton evaporation engine」の詳細全文を読む スポンサード リンク
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