Types of compressor
Positive displacement
Dynamic
Positive displacement comp types
Reciprocrating
Rotary
Dynamic compressor types
Centrifugal
Axial
Low pressure comp
Medium pr
High pr
10 bar
10-80
Above 80
Advantages of reciprocating comp
Used for low discharge at high pr
Pr upto 1000 bar
Low space requirement
What is stroke length
Distance btwn TDC & BDC
Isothermal efficiency of compressor
Work isothermal comp/work actual compression
Approximate clearance volume
5%
Pv diagram of actual reciprocating compressor
4 procceses of reci comp
2 constant pressure
2 isentropic
Volumetric efficiency formula
Actual volume/Stroke volume
1+C-C(p2/p1) ^1/n
What happens to volumetric efficiency when pressure ratio increases
Decreases
Why multi stage compression is needed
If pressure is increased in just single stage compression then work input increases and volumetric efficiency decreases
👉 Higher pressure ratio → more expansion needed → delayed suction → less fresh air → lower volumetric efficiency
Schematic dia of multi stage compression
Why intercooler is used between two compressor
It minimizes work input required by the compressor
Intercooler cool the compressed air when temp decreases volume also decreases
So less volume compress cheythal mathi
Perfect intercooler
Aa bagam video onnoode kananam
Pressure ratio value
7
___ valves arw provided in reciprocating compressor
Plate
Clearance formula wtr to stroke length
C= (0.005L+0.5) mm
