抽象 S.J.T.U. Phase Transformation and Applications Energy as work Carnot engine: Quasistatically,reversible 低温热源为什么要存在？ SJTU Thermodynamics of Materials Fall 2010 ©X.J.Jin Lecture 4 Second law ll
Phase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Fall 2010 © X. J. Jin Lecture 4 Second law II 抽象 Carnot engine: Quasistatically, reversible 低温热源为什么要存在？
热机 S.J.T.U. Phase Transformation and Applications A D D B B We need a way to reduce the pressure of the gas inside the cylinder,so that during the compression stage less work has to be done to drive the piston back in.adiabatically The essential step in the carnot cycle is to break the thermal contact with the hot reservoir before the piston is fully withdrawn,at B. SJTU Thermodynamics of Materials Fall 2010 ©X.J.Jin Lecture 4 Second law ll
Phase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Fall 2010 © X. J. Jin Lecture 4 Second law II 热机 We need a way to reduce the pressure of the gas inside the cylinder, so that during the compression stage less work has to be done to drive the piston back in. adiabatically The essential step in the carnot cycle is to break the thermal contact with the hot reservoir before the piston is fully withdrawn, at B
热机2 S.J.T.U. Phase Transformation and Applications Pressure OA Isothermal expansion Carot cycle Isothermal compression Pressure Volume Atkins cycle OA Only reversible isothermal process Volume SJTU Thermodynamics of Materials Fall 2010 ©X.J.Jin Lecture 4 Second law ll
Phase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Fall 2010 © X. J. Jin Lecture 4 Second law II 热机2 Atkins cycle Only reversible isothermal process Carot cycle
第二定律 S.J.T.U. Phase Transformation and Applications 1842年在热力学第一定律被发现之前，卡诺定理 工作在两个热源之间的热机以卡诺热机的效率最高 卡诺认为：热机是通过把热量从高温热源传到低温热源而作功的， 热量本身并没有消耗。犹如水力作功，热质说。 热力学第二定律/否定的方式来阐述的！ Clausius:不可能把热量从低温物体传到高温物体而不引起其它变化 。 1850年 Kelvin:不可能从单一热源吸热使之完全变成有用的功而不引起其它 的变化；1851年/第二类永动机机不可能 强调“不引起其它变化” 最终的唯一效果 SJTU Thermodynamics of Materials Fall 2010 ©X.J.Jin Lecture 4 Second law ll
Phase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Fall 2010 © X. J. Jin Lecture 4 Second law II 第二定律 1842年在热力学第一定律被发现之前，卡诺定理 工作在两个热源之间的热机以卡诺热机的效率最高 卡诺认为：热机是通过把热量从高温热源传到低温热源而作功的， 热量本身并没有消耗。犹如水力作功，热质说。 热力学第二定律/否定的方式来阐述的！ Clausius: 不可能把热量从低温物体传到高温物体而不引起其它变化 。1850年 Kelvin: 不可能从单一热源吸热使之完全变成有用的功而不引起其它 的变化；1851年 /第二类永动机机不可能 强调“不引起其它变化” 最终的唯一效果