Thermodynamic System

Here you can get What is thermodynamic system. Here we provides thermodynamic system of types, First Law and Second Law of Thermodynamics.

A thermodynamic system is a body of matter and/or radiation, confined in space by walls, with defined permeabilities, which separate it from its surroundings. The surroundings may include other thermodynamic systems, or physical systems that are not thermodynamic systems.

What is Thermodynamic System?

A thermodynamic system is defined as a amount of matter or a region in space which is chosen for the study. The mass or region outside the system is called surroundings. The actual or imaginary surfaces which separates the system and surroundings is referred to as boundary. The boundary of a system can be fixed or movable.

To understand the system, surroundings and the boundary in a ways better manner let’s take an example. Considered a closed vessel on which we’re going to do our study. Since we’re doing our study on the vessel so it is the system and the area except for the closed vessel is referred to as as surroundings. The surface of the closed vessel that separates the vessel and surroundings is referred to as boundary. Finally anything on which we pay our attention for the study or analysis is called system.

Types of Thermodynamic Systems

There are three mains types of system: open system, closed system and isolated system. All these have been described below:

Open system:

The system in which the transfer of mass as well as energy can take place across its boundary is known as as an open system. Our previous example of engine is an open system. In this case we provide gasoline to engine and it produces power which is given out, as a result there’s change of mass as well as energy. The engine also emits heat which is exchanged with the surroundings. The other example of open system is boiling water in an open vessel, where transfer of heat as well as mass in the shape of steam takes area among the vessel and surrounding.

Closed system:

The system wherein the transfer of energy takes place across its boundary with the surrounding, but no transfer of mass takes area is known as as closed system. The closed system is constant mass system. The fluid like air or gas being compressed in the piston and cylinder arrangement is an example of the closed system. In this case the mass of the gas stays constant but it can get heated or cooled. Another example is the water being heated in the closed vessel, wherein water gets heated however its mass will remain same.

Isolated system:

The system wherein neither the transfer of mass nor that of energy takes area across its boundary with the surroundings is known as as isolated system. For instance if the piston and cylinder association wherein the fluid like air or gas is being compressed or accelerated is insulated it will become isolated system. Here there will neither transfer of mass nor that of power. Similarly warm water, coffee or tea kept in the thermos flask is closed system. However, if we pour this fluid in a cup, it will become an open system.

The First Law of Thermodynamics

The first law of thermodynamics thinks big: it deals with the overall quantity of energy in the universe, and in particular, it states that this total amount does not change. Put another way, the First Law of Thermodynamics states that energy can not be created or destroyed. It can only change form or be transferred from one item to another.

This law may seem kind of abstract, but if we start to look at examples, we’ll find that transfers and transformations of energy take place
around us all of the time. For example:

  • Light bulbs transform electrical energy into mild energy (radiant energy).
  • One pool ball hits another, transferring kinetic energy and making the second ball move.
  • Plants convert the energy of sunlight (radiant energy) into chemical energy stored in organic molecules.
  • You are transforming chemical energy from your last snack into kinetic energy as you walk, breathe, and move your finger to scroll up and down this page.

Importantly, none of those transfers is absolutely efficient. Instead, in each scenario, some of the starting energy is released as thermal energy. When it is shifting from one item to another, thermal energy is called by the more familiar name of warmth. It’s obvious that glowing light bulbs generate heat in addition to mild, but moving pool balls do too (thanks to friction), as do the inefficient chemical energy transfers of plant and animal metabolism. To see why this warmth generation is important, stay tuned for the Second Law of Thermodynamics.

The Second Law of Thermodynamics

At first glance, the first law of thermodynamics may seem like great news. If energy is never created or destroyed, that means that energy can just be recycled over and over again, right? Well…yes and no. Energy cannot be created or destroyed, but it can change from more-useful forms into less-useful forms. As it turns out, in every real-world energy transfer or transformation, some amount of energy is converted to a form that’s unusable (unavailable to do work). In most cases, this unusable energy takes the form of heat.

Although heat can in fact do work under the right circumstances, it can never be turned into other (work-performing) types of energy with 100% efficiency. So, every time an energy transfer happens, some amount of useful energy will move from the useful to the useless category.

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