What Does thermodynamic system Mean
System is the module of elements that are interrelated with each other and that maintain interactions. Thermodynamic , for its part, is the field of physics that is responsible for studying the links that heat establishes with other forms of energy.
The thermodynamics , therefore, is a scientific discipline whose object of study is the energy exchange between a body and the environment . In this context, we can say that a thermodynamic system is a set of bodies that is isolated from the environment for study.
Such isolation can occur in a real way through an experimental field or in an ideal ( theoretical ) way. The aim is always to study the exchanges of energy and matter that take place inside the system.
The universe of the thermodynamic system is formed by the system itself (the set of bodies ) and the environment . The surface that is responsible for the separation of the system and the environment is called a wall or border . According to the characteristics of this wall, that is, to its ability to carry out insulation with respect to the environment, we can speak of different kinds of thermodynamic system:
* isolated : this thermodynamic system does not carry out an exchange of energy or matter with the environment. In other words, it can be said to be in thermodynamic equilibrium . A case in which this can be appreciated is that of a gas that is trapped in a container with resistant walls and a considerable thickness (called adiabatic walls), so that the degree of heat energy exchange is not significant and neither can there is an energetic exchange in the form of work;
* closed : it is a thermodynamic system that can exchange energy with the environment, but not matter. This particular class has many examples that represent it, and some are as everyday as a can of preserves, since their walls are not as thick and rigid as those of an isolated system;
* open : most of the thermodynamic systems that can be found on a daily basis are included in this class. A very easy to understand example is a car, since it carries out a matter exchange with the outside every time a person sits inside, fills their fuel tank, charges their battery or through the emission of gases through the exhaust pipe. On the other hand, an energy exchange also takes place in the form of heat , which is very easy to appreciate both inside and outside the vehicle.
Another way to classify thermodynamic systems is taking into account their homogeneity, which results in the following two classes:
* homogeneous : is one whose macroscopic properties correspond in any of its parts. This kind of system can be in any state of aggregation. Three examples in which these characteristics are fulfilled are a solid and pure substance that is in the crystallized state in the form of a single crystal, a gas that is trapped in a closed container or a quantity of pure water.
* heterogeneous : its definition is the opposite of the homogeneous system.
Another class of thermodynamic system is the adiabatic one , which allows the exchange of energy in the form of work , but not of heat energy (nor of matter).
A system is in thermodynamic equilibrium when its intensive variables do not change despite the passage of time . It should be remembered that these variables are those that do not change in value depending on the amount of matter or the size of the system.