3.2 The Second Law of Thermodynamics Clausius statement:it is impossible for any device to operate in a cycle in such a manner that the sole effect is the transfer of heat frol body at a higher temperature h one body to another Kelvin-Planck statement:"no process is possible whose sole result is the absorption of heat from a reservoir and the conversion of this heat into work The second perpetual motion machine is no way 4上一内容下一内容令回主目录 返回 2021/2/22
上一内容 下一内容 回主目录 返回 2021/2/22 3.2 The Second Law of Thermodynamics Clausius statement： “it is impossible for any device to operate in a cycle in such a manner that the sole effect is the transfer of heat from one body to another body at a higher temperature.” Kelvin-Planck statement： “no process is possible whose sole result is the absorption of heat from a reservoir and the conversion of this heat into work.” The second perpetual motion machine is no way!
Measuring dispersal. the entropy The first law led to the introduction of the internal energy, a property of state. The Second Law also leads to a property, the entropy. The First law uses the internal energy to identify the permissible changes, the Second law uses the entropy to identify the natural changes among these permissible changes 4上一内容下一内容令回主目录 返回 2021/2/22
上一内容 下一内容 回主目录 返回 2021/2/22 Measuring dispersal : the entropy The First Law led to the introduction of the internal energy, a property of state. The Second Law also leads to a property, the entropy. The First Law uses the internal energy to identify the permissible changes; the Second Law uses the entropy to identify the natural changes among these permissible changes
The statistical view of the entropy One way of introducing the entropy develops the view that the extent of the dispersal of energy can be calculated this leads to the statistical definition of entropy. Another develops the view that the dispersal can be related to the amount of heat involved in a process: this leads to the thermodynamic definition 4上一内容下一内容◇回主目录 返回 2021/2/22
上一内容 下一内容 回主目录 返回 2021/2/22 The statistical view of the entropy One way of introducing the entropy develops the view that the extent of the dispersal of energy can be calculated: this leads to the statistical definition of entropy. Another develops the view that the dispersal can be related to the amount of heat involved in a process: this leads to the thermodynamic definition
Carnot Cycle Of particular interest is an 高温存储器 idealized engine, known as On the Carnot engine, which employs two heat 热机 reservoirs at different temperatures and operates on the following cycle 低温存储器 卡诺循环 4上一内容下一内容◇回主目录 返回 2021/2/22
上一内容 下一内容 回主目录 返回 2021/2/22 Carnot Cycle Of particular interest is an idealized engine, known as the Carnot engine, which employs two heat reservoirs at different temperatures and operates on the following cycle
Carnot cycle Process 1: A reversible isothermal expansion at Th Process 2. A reversible adiabatic expansion A(p1 V1) Process 3 A reversible isothermal B(lava compression at T2 D(p4 V4 C(p3 Vs) Process 4: A reversible adiabatic compression 卡诺循环 4上一内容下一内容令回主目录 返回 2021/2/22
上一内容 下一内容 回主目录 返回 2021/2/22 Carnot cycle Process 4: A reversible adiabatic compression Process 3: A reversible isothermal compression at T2 Process 2: A reversible adiabatic expansion. Process 1: A reversible isothermal expansion at Th