Introduction to Thermodynamics and Heat Transfer

Abstract

Thermodynamics is the science that deals with the exchange of energy in the form of heat and work and with the different states (solid, liquid, gas, etc.) and properties (density, viscosity, thermal conductivity, etc.) of substances that are related to energy and temperature. Thermodynamics is formalized into three basic laws, the first law being the conservation of energy, and the second and third laws being related to the notion of entropy and is completed by the three main laws for heat transfer: radiation, convection, and conduction. In this chapter, we introduce first the properties of substances (density, pressure, and temperature), energy, enthalpy, and entropy, then the concept of state variables, the different types of thermodynamic systems, the first and second thermodynamic laws, the thermodynamics cycles (ideal and actual Brayton cycles, ideal and actual Rankine cycles), the ideal gas law, and the three heat transfer processes (radiation, convection, and conduction). It is shown why these different notions are essential in order to compute the complete thermal-hydraulic state of the system, which is the main challenge of 0D/1D modeling and simulation for that field.