tailieunhanh - Ebook Thermodynamics (7th edition): Part 2
(BQ) Part 2 book "Thermodynamics" has contents: Gas power cycles, vapor and combined power cycles, refrigeration cycles; thermodynamic property relations, gas mixtures, gas mixtures, chemical reactions, chemical and phase equilibrium, chemical and phase equilibrium,. and other contents. | CHAPTER GAS P O W E R C Y C L E S wo important areas of application for thermodynamics are power generation and refrigeration. Both are usually accomplished by sys tems that operate on a thermodynamic cycle. Thermodynamic cycles can be divided into two general categories: power cycles, which are dis cussed in this chapter and Chap. 10, and refrigeration cycles, which are discussed in Chap. 11. The devices or systems used to produce a net power output are often called engines, and the thermodynamic cycles they operate on are called pow er cycles. The devices or systems used to produce a refrigeration effect are called refrigerators, air conditioners, or heat pumps, and the cycles they operate on are called refrigeration cycles. Thermodynamic cycles can also be categorized as gas cycles and vapor cycles, depending on the phase of the working fluid. In gas cycles, the working fluid remains in the gaseous phase throughout the entire cycle, whereas in vapor cycles the working fluid exists in the vapor phase during one part of the cycle and in the liquid phase during another part. Thermodynamic cycles can be categorized yet another way: closed and open cycles. In closed cycles, the working fluid is returned to the initial state at the end of the cycle and is recirculated. In open cycles, the working fluid is renewed at the end of each cycle instead of being recirculated. In automobile engines, the combustion gases are exhausted and replaced by fresh air-fuel mixture at the end of each cycle. The engine operates on a mechanical cycle, but the working fluid does not go through a complete thermodynamic cycle. Heat engines are categorized as internal combustion and external combus tion engines, depending on how the heat is supplied to the working fluid. In external combustion engines (such as steam power plants), heat is supplied to the working fluid from an external source such as a furnace, a geothermal well, a nuclear reactor, or even the sun. In internal combustion .
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