- Types of thermodynamic systems
- 15 concrete examples of thermodynamic systems
- Closed systems
- Open systems
- Isolated systems
- References
The thermodynamic systems are the object of study of thermodynamics. A system can be defined as a certain amount of matter, or a region in space where attention is focused on the analysis of a problem.
On the other hand, the term thermodynamic was coined by the British physicist and mathematician Thomson, who combined the Greek roots for heat (Θέρμη: thermo) and power or force (δύναμις: dynamis).
Thermodynamics is the branch of physics that is responsible for studying heat and its potential to produce energy, and the properties related to both aspects.
Types of thermodynamic systems
In the first instance, some of the basic concepts related to thermodynamic systems are environment, system boundary and universe.
The environment is everything external to the system, and its limit is the interface that separates it from the environment. Finally, the universe is the combination of these two elements.
A thermodynamic system can be any amount of substance, specimen or machine that is separated from its environment in a well-defined way.
This separation can be real or imagined. It should also be considered that neither the geometry, nor the chemical composition, nor the physical state of thermodynamic systems are predetermined, therefore any of them can change.
On the other hand, there are three types of thermodynamic systems: closed, open and isolated. In closed systems, energy can be transferred between the system and its surroundings, but not mass.
If both can be transferred, then it is an open system. On the other hand, if there is no type of interaction with the environment, the system is isolated.
15 concrete examples of thermodynamic systems
Closed systems
In the cases of closed thermodynamic systems, matter does not cross the system boundary. However, energy can cross it, but in the form of heat or work. The following systems illustrate this type:
-Sealed pneumatic pistons
-Refrigerant in a refrigeration system
-Calorimeter
-The planet Earth (it obtains energy from the Sun, but practically does not exchange matter with the outside).
-Pressure pot (if the system is totally closed, there is risk of explosion)
Open systems
In this type of system, there is an exchange of energy with the environment, and there is no impediment for the mass or matter to cross the limits of the system.
Also, work is done on or by the system. Some examples of open thermodynamic systems include:
-Boiling water in a pot without a lid (heat and steam, which is matter, escape into the air)
-Turbines
-Compressors
-Heat exchangers
-The human body
Isolated systems
An isolated system is one where work is not done in or by the system. Neither is heat removed or added from the system.
Also, matter does not flow into or out of it. Very few thermodynamic systems are totally isolated. Examples of this are:
-Rigid sealed steel cylinder containing liquid nitrogen
-A neoprene suit
-Oxygen cylinders
-The entire physical universe
-A thermos (to keep things cold or hot)
References
- Wu, C. (2002). Intelligent Computer Based Engineering Thermodynamics and Cycle Analysis. New York: Nova Publishers.
- Nag, PK (2013). Engineering Thermodynamics. New Delhi: McGraw-Hill Education.
- Han, F. (2017). A Modern Course in University Physics: Optics, Thermal Physics, Modern Physics. Singapore: World Scientific Publishing Company.
- Freiesleben Hansen, P. (2009). The Science of Construction Materials. London: Springer Science & Business Media.
- Rauf, BS (2012). Thermodynamics Made Simple for Energy Engineers. Georgia: The Fermont Press.