Types Of Thermodynamic Systems

In order to study thermodynamics;
The universe is divided into two parts, the system, and the surrounding. The part of the universe under observation is called the system and all things in the universe except the system are called surroundings. It is a region where measurements are made relative to the system. 
The system's alterations have no impact on the rest of the universe. As a result, the part of the universe that interacts with the system is referred to as the surrounding in experimental work. The real or imaginary surface that separates the system and surroundings is called boundary. 

The type of system depends on the characteristics of the boundary that divides it from the surrounding. In this article, we will learn about these different types of thermodynamic systems with the help of various examples.


Thermodynamic Systems
As we know that the systems and the surroundings interact with each other based on the transfer of matter and energy. Therefore, thermodynamic systems are classified on the basis of these mass and energy transfers as follows;
(1)Open System
"When both mass and energy are transferred between the system and the surroundings, the system is said to be an open system". An open system is sometimes referred to as "Control volume" 
(The control volume is the region of space within the boundaries of the system in which both mass and energy are transferred between the system and its surroundings).
For Example- 
Reactants in an open beaker, A human body, a cup of tea, steam engine, boiling water in a bowl, Water pump, etc.

(2) Closed System
"When only energy is transferred between the system and the surrounding, not matter. Then that system is called closed system". 
Closed systems are not real. They are imaginary systems. 
For Example; 
A beaker of evaporating water with a closed lid on it allows the transfer of energy to the surroundings but does not allow (matter) water to leave. 
Other Example- 
Reactants in a closer beaker, A pressure cooker, Hot water kept inside a PETE bottle, Frying pan on a stove when it's lid is closed, the sun, Human body, Thermostat, Air conditioner, Steering of car, etc.

The earth can be considered as a closed system because it can exchange energy with the surroundings, but not mass. Due to which its overall mass remains constant.

(3) Isolated System
"In an isolated system, the exchange of both mass and energy between the system and the surroundings is not possible (No interaction between system and surrounding)". 
Since there is no mass interaction between the system and the surrounding, the system has a fixed mass and is sometimes referred to as a control mass system. 
For Example- 
Universe is an example of isolated system, A closed thermos bottle or a sealed vacuum flask, bomb calorimeter, etc.

(4) Rigid System
"A rigid system is a type of closed system in which the energy transfer between the system and its surroundings takes place only in the form of heat". 
This means that mechanical work cannot transfer between the system and the surroundings. In this, neither the system works on the surrounding nor the surrounding works on the system.

(5) Insulated System
An insulated system is a system in which heat cannot be transferred between the system and the surroundings, but work can be transferred between them as well as there is a possibility of mass transfer. 

(6) Adiabatic System
"An adiabatic system is a system in which no heat and mass can be exchanged between the system and its surroundings, but there is a possibility of transfer of work between them". Therefore, such a system can be compressed or expanded which will increase or decrease the temperature of the system as work is done by or on the system.


FAQs
Is Earth An Open Or Closed System?
Earth is a closed system because it allows only the exchange of energy but does not allow the exchange of matter. It receives the energy from the sun and radiates it back to space. This is a natural process.
Is The Universe An Open Or A Closed System?
The universe is neither an open system, closed system nor an isolated system. The observed universe in which we can observe all things is an open system because it can exchange both matter and energy with the boundary that we cant see. The entire universe seems to be an isolated system because there is no other boundary to transfer energy or matter.
What Is A Non-flow Process?
It is a process in which no mass transfer takes place between the system and surroundings. Examples of the non-flow process are the isochoric (constant volume) process, isobaric (constant pressure) process, and isothermal (constant temperature) process.
What Is The Difference Between A Flow And A Non-flow Process?
The flow process occurs in an open system in which mass interaction is possible between the system and surroundings. For example, water is flowing in and out of the pipe, etc. 
whereas the non-flow process occurs in a closed system in which no interaction of mass is possible with the surrounding. For example, a cup of tea with a lid on it, etc.



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