The First and Second Laws of Thermodynamics

Abstract

The science of thermodynamics is built primarily on two fundamentally natural laws, known as the first and second laws. The first law of thermodynamics is simply an expression of the conservation of energy principle. It asserts that energy is a thermodynamic property, and that during an interaction, energy can change from one form to another but the total amount of energy remains constant. The second law of thermodynamics asserts that energy has quality as well as quantity, and actual processes occur in the direction of decreasing quality of energy. The attempts to quantify the quality or “work potential” of energy in light of the second law of thermodynamics has resulted in the definition of the property named exergy. In this chapter, basic relations for the first and second laws of thermodynamics are provided for closed systems and control volumes. The concepts of entropy and exergy derived from the second law are thoroughly discussed.KeywordsEntropy ChangeEntropy GenerationHeat EngineExergy AnalysisExergy EfficiencyThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.