What is thermodynamic system. Differentiate various types of thermodynamic systems.

Thermodynamics System: In thermodynamics the system is defined as the quantity of matter or region in space upon which the attention is concentrated for the sake of analysis. These systems are also referred to as thermodynamics system.

Boundary: It is bounded by an arbitrary surface called boundary. The boundary may be real or imaginary, may be at rest or in motion and may change its size or shape.

Surrounding: Everything out side the arbitrary selected boundaries of the system is called surrounding or environment.
The union of the system and surrounding is termed as universe.
Universe = System + Surrounding

Types of system
The analysis of thermodynamic processes includes the study of the transfer of mass and energy across the boundaries of the system. On the basis the system may be classified mainly into three parts.

1. Open system.
2. Closed System.
3. Isolated system

Open system
The system which can exchange both the mass and energy (Heat and work) with its surrounding. The mass within the system may not be constant. The nature of the processes occurring in such system is flow type.
For example
1. Water Pump: Water enters at low level and pumped to a higher level, pump being driven by an electric motor. The mass (water) and energy (electricity) cross the boundary of the system (pump and motor).
2.Scooter engine: Air arid petrol enter and burnt gases leave the engine. The engine delivers mechanical energy to the wheels.
3. Boilers, turbines, heat exchangers. Fluid flow through them and heat or work is taken out or supplied to them. Most of the engineering machines and equipment are open systems.

Closed System
The system, which can exchange energy with their surrounding but not the mass. The quantity of matter thus remains fixed. And the system is described as control mass system. The physical nature and chemical composition of the mass of the system may change. Water may evaporate into steam or steam may condense into water. A chemical reaction may occur between two or more components of the closed system.
For example
1. Car battery, Electric supply takes place from and to the battery but there is no material transfer.
2. Tea kettle, Heat is supplied to the kettle but mass of water remains constant.
3. Water in a tank
4. Piston – cylinder assembly.

Isolated System
In an Isolated system, neither energy nor masses are allowed to cross the boundary. The system has fixed mass and energy. No such system physically exists. Universe is the only example, which is perfectly isolated system.

Difference between Fan and Blower

Key difference: Both, fans and blowers, are mechanical devices used for circulation of air. Based on this, they are differentiated from each other, wherein a fan circulates air around an entire room, or space, and a blower only focuses on the specific or given area.

Generally, a fan is an electrical device that moves air, whereas a blower is a mechanical device that consists of a fan, and which channels the air from the fan and directs it to a specific location or point. Also, a fan circulates the air around an entire room or a large area, while a blower is only positioned to a specific direction or point.

Fan

By definition, a fan is machine that is used to create flow within a fluid, such as air. It consists of vanes or blades that rotate and act on air. This rotating assembly of blades and hub is known as an impeller, a rotor, or a runner. The impellers help in directing the air flow, and producing air at low pressure. Most fans are powered by electric motors, but other sources such as hydraulic motors and internal combustion engines can also be used.

Blower

On the other hand, a blower is defined as a machine which is used to produce large volumes of gas with a moderate increase in pressure. Similar to fans, blowers are also used to create air, but they only provide air at a specified position. It consists of a wheel with small blades on its circumference, and a casing to direct the flow of air out toward the edge. The casing in the center of the wheel uses centrifugal force to propel the air forward into the open.

	Fan	Blower
Definition	A fan circulates air around an entire room, or space.	A blower circulates the air only on the specific or pointed area.
Pressure	It is uses less pressure to produce large amounts of gas.	It is uses high pressure to produce large amounts of gas.
Pressure ratio	The ratio of pressure is below 1.1.	The ratio of pressure is from 1.1 to 1.2.
Air area	It provides air in the complete area.	It provides air in a specific location or point.
Types	Axial flow fans. Centrifugal fans. Cross- flow fans.	Centrifugal blowers. Positive-displacement blowers.
Consists of	It consists of a motor and blades, which run of electricity.	It consists of a fan, outer cover, inlet, out-let.

What are the difference between fan, blower, compressor & pump?

Fan:

• A fan moves large amounts of gas with a low increase in pressure

Blower:

• A blower is a machine for moving volumes of a gas with moderate increase of pressure.: a more powerful fan, if you will. By changing the angle of the blades, a blower will be able to push air in any direction you want it.

Compressor:

• A compressor is a machine for raising a gas – a compressible fluid – to a higher level of pressure., actually making the air denser by cramming air into a small space.

Pump:

• A pump is a machine for raising a liquid – a relatively incompressible fluid – to a higher level of pressure or head.