熵增原理一热力学第二定律的普遍描述 S.J.T.U. Phase Transformation and Applications δQ为为系统从温度为T的热源吸取的热量 0 可逆过程的热温商为零，所定义的熵为状态函数 设系统由初态A变为终态B,设系统经过一个 设想的可逆过程由状态B回到状态A 片2+<0 T =S4-Sa 5n-5,≥g9 热力学第二定律对过程的限制，违反上述不等式的过程是不可能发生的！ SB-SA≥0 绝热条件下 SJTU Physical Chemistry of Materials Spring 2005 ©X.J.Jin Lecture 5 property relation
Phase Transformation and Applications S. J. T. U. SJTU Physical Chemistry of Materials Spring 2005 © X. J. Jin Lecture 5 property relation 熵增原理－热力学第二定律的普遍描述 Q 0 T δ v∫ ≤ δQ为为系统从温度为T的热源吸取的热量 可逆过程的热温商为零，所定义的熵为状态函数 A B 设系统由初态A变为终态B，设系统经过一个 设想的可逆过程由状态B回到状态A B A rev A B Q Q 0 T T δ δ ∫ ∫ + ≤ A rev A B B Q S S T δ ∫ = − B B A A Q S S T δ − ≥ ∫ 热力学第二定律对过程的限制，违反上述不等式的过程是不可能发生的！ SS0 B A − ≥ 绝热条件下
Summary S.J.T.U. Phase Transformation and Applications Some heat must be discarded into a cold sink in order for Hot Source Entropy falls us to generate enough entropy to overcome the Heat withdrawn decline taking place in the hot reservoir Surroundings Energy stored at a high Work temperature has a better Heat dumped "quality":high-quality energy Cold sink Entropy is available for doing work; increases low-quality energy,corrupted energy,is less available for doing work冬季取暖/进化 SJTU Physical Chemistry of Materials Spring20o5©X.J.Jin Lecture 5 property relation
Phase Transformation and Applications S. J. T. U. SJTU Physical Chemistry of Materials Spring 2005 © X. J. Jin Lecture 5 property relation Some heat must be discarded into a cold sink in order for us to generate enough entropy to overcome the decline taking place in the hot reservoir Energy stored at a high temperature has a better “quality”: high-quality energy is available for doing work; low-quality energy, corrupted energy, is less available for doing work冬季取暖/进化 Summary
热力学第二定律几点说明！ S.J.T.U. Phase Transformation and Applications 过程 研究过程方向问题（任务）《一 一不可能的过程 体系十环境（孤立体系熵增原理 一可能的过程 )《一热力学第二定律（基础但 ·可逆 不好用) ·不可逆（自发）过程 熵为体系的状态函数/平衡状态 B T SJTU Physical Chemistry of Materials Spring 2005 ©X.J.Jin Lecture 5 property relation
Phase Transformation and Applications S. J. T. U. SJTU Physical Chemistry of Materials Spring 2005 © X. J. Jin Lecture 5 property relation 热力学第二定律几点说明！ 过程 – 不可能的过程 – 可能的过程 • 可逆 • 不可逆（自发）过程 熵为体系的状态函数/ 平衡状态 研究过程方向问题（任务）《－ 体系＋环境（孤立体系熵增原理 ）《－热力学第二定律（基础但 不好用） TI TII A B
Diescyle S.J.T.U. Phase Transformation and Applications Fuel injector Fuel injection and combustion Glow plug Prechamber starting aid b Intake Exhaust Exhaust Intake valve valve a Combustion Power stroke chamber Piston Adiabatic compression Cylinder 02 Exhaust a Carnot efficiency Drive shaft After Devins T4-ex10% 9 Volume,V Heat 人 8p8s00 Out lsothermal compression at Te Volume SJTU Physical Chemistry of Materials Spring 2005 ©X.J.Jin Lecture 5 property relation
Phase Transformation and Applications S. J. T. U. SJTU Physical Chemistry of Materials Spring 2005 © X. J. Jin Lecture 5 property relation Diescyle
Refrigerator S.J.T.U. Phase Transformation and Applications Expansion valve Expansion lowers pressure forcing vaporization pressure All real Hot reservoir Hot Cold refrigerators area area Cooling require coils work to 十十十 get heat to flow from Refrigerator a cold area Compressor to a warmer area. Cold reservoir Compression High forces pressure liquification SJTU Physical Chemistry of Materials Spring 2005 ©X.J.Jin Lecture 5 property relation
Phase Transformation and Applications S. J. T. U. SJTU Physical Chemistry of Materials Spring 2005 © X. J. Jin Lecture 5 property relation Refrigerator