Air cooled chiller working

In this system, there are 2 cycles.

1) Refrigeration cycle

2) Water cycle between AHU and evaporator

Refrigeration Cycle:

Parts required are:

a) Compressor

b) Fin type condenser

c) Expansion Valve

d) Evaporator

Working:

• The compressor starts to compress the vapor refrigerant which comes from the evaporator and converts it into high-temperature vapor refrigerant and flows into the fin-type condenser.
• Ambient air will pass over the condenser and absorbs heat from the high-temperature vapor refrigerant.
• After rejecting heat to the ambient air, it gets converted into a hot liquid refrigerant.
• This hot liquid-vapor refrigerant will flow into the expansion device and it will reduce the pressure of the refrigerant suddenly. Due to this, it will get converted into a low-temperature liquid refrigerant.
• This low-temperature liquid refrigerant will flow to the evaporator and absorb heat from the water which comes from the AHU and it will get converted into vapor refrigerant. Vapour refrigerant will flow to the compressor.
• Again compressor will start to compress and the process continues.

Water cycle between AHU and evaporator:

Parts required are:

a) AHU

b) Shell and tube type Evaporator

Working:

• Cool water which comes from the shell side of the evaporator flows into the cooling coil of AHU.
• In AHU, the blower sucks returned air and fresh air, which flows over the cooling coil. 
• When it passes over the cooling coil, it rejects the heat because the cooling coil has chilled water that has a very low temperature as compared to the return air.
• After absorbing heat, chilled water converts into hot water and it flows to the evaporator shell side.
• The tube side of the evaporator has low-temperature liquid refrigerant and it absorbs heat from the hot water(which is on the shell side of the evaporator).
• After rejecting the heat to the liquid refrigerant it converts into chilled water and again it will flow to the AHU and the process continues.