Difference Between Heat Transfer and Thermodynamics

Heat Transfer vs Thermodynamics
 

Heat transfer is a topic discussed in thermodynamics. The concepts of thermodynamics are very important in the study of physics and mechanics as a whole. Thermodynamics is considered as one of the most important fields of study in physics. It is vital to have a proper understanding in the concepts of heat transfer and thermodynamics in order to excel in fields that have applications of these concepts. In this article, we are going to discuss what heat transfer and thermodynamics are, their definitions and applications, the similarities between thermodynamics and heat transfer and finally the difference between thermodynamics and heat transfer.

Thermodynamics

Thermodynamics can be divided into two main fields. The first one is classical thermodynamics, and the second one is statistical thermodynamics. Classical thermodynamics is considered as a “complete” field of study, which means the study of classical thermodynamics is finished. However, statistical thermodynamics is still a developing field with lots of open doors.

Classical thermodynamics is based on the four laws of thermodynamics. The zeroth law of thermodynamics describes the thermal equilibrium, the first law of thermodynamics is based on the conservation of energy, the second law of thermodynamics is based on the concept of entropy and the third law of thermodynamics is based on the Gibbs free energy. Statistical thermodynamics is largely based on the quantum level, and the microscopic level motion and mechanics are considered with thermodynamics and mainly deals with statistics.

Heat Transfer

When two objects, which have thermal energy, are exposed, they tend to transfer energy in the form of heat. To understand the concept of heat transfer one must first understand the concept of heat. Thermal energy also known as heat is a form of internal energy of a system. Thermal energy is the cause for the temperature of a system. The thermal energy occurs due to the random movements of the molecules of the system. Every system having a temperature above absolute zero has a positive thermal energy. The atoms themselves do not contain any thermal energy. The atoms have kinetic energies. When these atoms collide with each other and with the walls of the system they release thermal energy as photons. Heating such a system will increase the thermal energy of the system. Higher the thermal energy of the system higher will be the randomness of the system.

Heat transfer is the movement of heat from one place to another. When two systems, which are thermally contacted, are in different temperatures, heat from the object at the higher temperature will flow to the object with a lower temperature until the temperatures are equal. A temperature gradient is necessary for a spontaneous heat transfer.

The rate of heat transfer is measured in watt, whereas the amount of heat is measured in joule. The unit watt is defined as joules per unit time.