Specific properties of water and steam Definition Specific properties are per kg. Examples are specific volume, specific enthalpy, specific entropy, specific internal energy and specific latent heat. Symbol These specific properties are represented by the small alphabet like v, h,s,u,cP etc. Reference temperature for the enthalpy and entropy of water is 00C. Enthalpy of water […]
Highlights – thermodynamic relations The equation of state is a relation between thermodynamic properties for ideal gas. However, simple equation of state is not applicable for thermodynamic properties with real gases. Hence, there is a need of more mathematical relations for the real gases. Fundamental thermodynamic properties temperature, pressure and volume are measurable. Derived thermodynamic […]
HIGHLIGHTS OF AVAILABILITY Availability is the maximum theoretical work which can be obtained by a heat engine. Since some heat is rejected in a heat engine, therefore recovery of maximum work is not possible. The work which cannot be recovered because of heat rejection to the surroundings is the unavailability. When heat is added to […]
AVAILABILITY, UNAVAILABILITY AND IR-REVERSIBILITY (a) Available Energy Available energy is related to the energy grade.There are two grades of energy available from the various sources. HIGH GRADE ENERGY It can be fully converted useful work (Shaft Work). Thus,it is not governed by the Second Law of Thermodynamics (no ir-reversibility).Examples of high grade energy are Mechanical work, […]
TRANSPORT PROPERTIES 5. TRANSPORT PROPERTIES–three These include the specific heat, viscosity and thermal conductivity. SPECIFIC HEATS There can be three values of Cp and three values of Cv depending upon whether the gas is mono-atomic, di-atomic or poly-atomic. As per Equi-partition theorem, energy is equally distributed for each degree of freedom by the amount […]
TEMPERATURE ENTROPY AND PRESSURE ENTHALPY CHARTS TEMPERATURE ENTROPY CHART As entropy is a thermodynamic parameter (property) like other thermodynamic parameters namely internal energy/enthalpy, it is used as abscissa (x –co-ordinate) and ABSOLUTE temperature as the ordinate. This chart is very useful in comparing the performance of various heat engine and refrigeration cycles.Although entropy is an […]
DERIVED THERMODYNAMIC PROPERTIES THERMODYNAMIC PROPERTIES (a) Fundamental Thermodynamic Properties–three Measurable properties like temperature, pressure and volume are the three fundamental thermodynamic properties. (b) Derived Thermodynamic Properties–three Non measurable properties like internal energy, enthalpy and entropy are called derived thermodynamic properties. Internal energy comes from the First Law of Thermodynamics Entropy comes from the Second Law of […]
THERMODYNAMIC TEMPERATURE AND SCALE Development of Thermodynamic Temperature Temperature is due to the random translation, rotational motions and vibrations of the submicroscopic particles. These motions constitute the internal energy of a substance. Thermodynamic temperature is the measure of the average kinetic energy per degree of freedom of its constituent particles. Therefore,it is one of the important […]
Maxwell relations and Exact differentials Natural Variables The variables which are kept constant in a process are called the natural variables of that potential. Thermodynamic potential can be found as a function of its natural variables only. Then only the thermodynamic properties of the system can be determined by taking partial derivatives of that potential […]
Thermodynamic potentials-Euler’s Law Thermodynamic potentials are useful in the thermodynamics of chemical reactions. These potentials also describe the non-cyclic processes. They are four thermodynamic potentials. These are internal energy, the enthalpy, the Helmholtz free energy and the Gibbs free energy. All the thermodynamic potentials are energy terms. These potentials cannot be measured as temperature or pressure. These […]