第二类永动机 perpetual-motion machine of the second kind 第二类永动机:设想的从单一热源取热并 使之完全变为功的热机 这类永动机 并不违反热力 学第一定律 但违反了热 力学第二定律 第二类永动机是不可能制造成功的 环境是个大热源
但违反了热 力学第二定律 第二类永动机 perpetual-motion machine of the second kind 第二类永动机：设想的从单一热源取热并 使之完全变为功的热机。 这类永动机 并不违反热力 学第一定律 第二类永动机是不可能制造成功的 环境是个大热源
Perpetual-motion machine of the second kind 汽轮机 锅炉 W net 发电机 给水泵 L二二
Perpetual –motion machine of the second kind 锅 炉 汽轮机 发电机 给水泵 凝 汽 器 Wnet Qout Q
3.克劳修斯说法与开尔文-普朗克说法等价 Equivalence of clausius and Kelvin-planck statements High Temperature Reservoir q Heat Engine Heat Pump Low Temperature Reaervoir Suppose we can construct a heat pump which transfers heat from a low temperature reservoir to a high temperature one without using external work Then we can couple it with a heat engine in such a way that the heat removed by the heat pump from the low temperature reservoir is the same as the heat rejected by the heat engine so that the combined system is now a heat engine which converts heat to work without any external effect e this is thus in violation of the kelvin planck statement of the second law
⚫ Suppose we can construct a heat pump which transfers heat from a low temperature reservoir to a high temperature one without using external work. ⚫ Then, we can couple it with a heat engine in such a way that the heat removed by the heat pump from the low temperature reservoir is the same as the heat rejected by the heat engine, so that the combined system is now a heat engine which converts heat to work without any external effect. ⚫ This is thus in violation of the Kelvin-Planck statement of the second law. 3.克劳修斯说法与开尔文-普朗克说法等价 Equivalence of Clausius and Kelvin-Planck Statements
High Temperature Reservoir 1-22 1 21-2 Heat Engine Heat Pump Low Temperature Reservoir Now suppose we have a heat engine which can convert heat into work without rejecting heat anywhere else We can combine it with a heat pump so that the work produced by the engine is used by the pump. Now the combined system is a heat pump which uses no external work, violating the Clausius statement of the second law Thus, we see that the clausius and kelvin-planck statements are equivalent and one necessarily implies the other
⚫ Now suppose we have a heat engine which can convert heat into work without rejecting heat anywhere else. ⚫ We can combine it with a heat pump so that the work produced by the engine is used by the pump. ⚫ Now the combined system is a heat pump which uses no external work, violating the Clausius statement of the second law. Thus, we see that the Clausius and Kelvin-Planck statements are equivalent, and one necessarily implies the other
两种表述的关系 开尔文一普朗克 表述 克劳修斯表述 完全等效! 违反一种表述,必违反另一种表述!
两种表述的关系 开尔文－普朗克 表述 完全等效!!! 克劳修斯表述： 违反一种表述,必违反另一种表述!!!