# Ch 6 - The Second Law of Thermodynamics

Why do we need the second law of thermodynamics? Click and learn. In this lesson, we review heat engines and thermal reservoirs and study the components that make up power, refrigeration, and heat pump cycles. Here we present a discussion of the Second Law of Thermodynamics and its importance in determining if a process is possible. We consider two different statements of the Second Law, the Clausius and the Kelvin-Planck statements. Here, we define the reversible process as the ideal process. In later lessons, we will compare all real processes to the ideal reversible process. We also discuss common sources of irreversibility and how they can be identified. Finally, we explain two other process classifications: internally reversible and externally reversible. In this lesson we introduce the Carnot Cycle for both closed and open systems. The Carnot Cycle is the reversible cycle against which the performance of all real cycles is compared. We also discuss the two Carnot Principles which are important attributes of Carnot Cycles. In this lesson, we define thermodynamic temperature scales. We proceed to show that the Kelvin Scale is a indeed thermodynamic temperature scale. We also show that the Ideal Gas and Kelvin Temperature Scales are identical. In this lesson, we use the function selected by Lord Kelvin to eliminate the Q's from the performance equations for REF's and
HP's. Then, we use the equation for the efficiency of a HE to show that energy has quality and that work is the most valuable form of energy. - Introduction to the 2nd Law of Thermo
- Heat Engines & Thermal Reservoirs
- The 2nd Law of Thermodynamics
- Reversible and Irreversible Processes
- The Carnot Cycle
- The Thermo & IG T-Scales
- Carnot Efficiency • The lessons in Chapter 6 are listed below
• Roll your mouse over the lesson title to see a brief description of the contents of the lesson
• Click on the lesson that you want to study