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Quantum Refrigerators
A quantum heat engine is a device that generates power from the heat flow between hot and cold reservoirs. The operation mechanism of the engine can be described by the laws of quantum mechanics. The first realization of a quantum heat engine was pointed out by Henry Evelyn Derek Scovil, Scovil and Schulz-DuBois in 1959, showing the connection of efficiency of the Nicolas Léonard Sadi Carnot, Carnot engine and the 3-level maser. Quantum refrigerators share the structure of quantum heat engines with the purpose of pumping heat from a cold to a hot bath consuming power first suggested by Geusic, Schulz-DuBois, De Grasse and Scovil. When the power is supplied by a laser the process is termed optical pumping or laser cooling, suggested by David J. Wineland, Wineland and Theodor W. Hänsch, Hänsch.D. J. Wineland and H. Dehmelt, Bull. Am. Phys. Soc. 20, 637 (1975) Surprisingly heat engines and refrigerators can operate up to the scale of a single particle thus justifying the need for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Engine
In thermodynamics and engineering, a heat engine is a system that converts heat to mechanical energy, which can then be used to do mechanical work. It does this by bringing a working substance from a higher state temperature to a lower state temperature. A heat source generates thermal energy that brings the working substance to the higher temperature state. The working substance generates work in the working body of the engine while transferring heat to the colder sink until it reaches a lower temperature state. During this process some of the thermal energy is converted into work by exploiting the properties of the working substance. The working substance can be any system with a non-zero heat capacity, but it usually is a gas or liquid. During this process, some heat is normally lost to the surroundings and is not converted to work. Also, some energy is unusable because of friction and drag. In general, an engine is any machine that converts energy to mechanical work. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
