Simple form of refrigeration cycle is shown in the
following figure :
Refrigeration cycle : is a closed loop where the refrigerant flows
through it .
The Refrigerant enters evaporator at low temperature low pressure,
where it absorbs the heat from the refrigerated space by convection heat
transfer between the air space and the refrigerant. Refrigerant leaves the
evaporator and enters the compressor as a slightly superheated vapor at a low
pressure, it then leaves the compressor at high pressure vapor to enters the
condenser, in condenser the heat absorbed during evaporated process of the
refrigerant, it will rejected by convection heat transfer between the
refrigerant and ambient air or cooling water, whereas the refrigerant will
condensate and leaves the condenser as a high pressure low temperature liquid.
The function of the expansion valve is to reduce the pressure of the
refrigerant before entering the evaporator.
The refrigerant's safety properties :
- unflamable
- nontoxic
- does not react with air and materials
- Cheap and easy production
Most common types of refrigerants :
Freons : R11 , R12 , R22 , R134 , R502 , R717 , R404
ammonia : NH3
Simple form of refrigeration cycle is shown in the
following figure :
Refrigeration cycle : is a closed loop where the refrigerant flows
through it .
The Refrigerant enters evaporator at low temperature low pressure,
where it absorbs the heat from the refrigerated space by convection heat
transfer between the air space and the refrigerant. Refrigerant leaves the
evaporator and enters the compressor as a slightly superheated vapor at a low
pressure, it then leaves the compressor at high pressure vapor to enters the
condenser, in condenser the heat absorbed during evaporated process of the
refrigerant, it will rejected by convection heat transfer between the
refrigerant and ambient air or cooling water, whereas the refrigerant will
condensate and leaves the condenser as a high pressure low temperature liquid.
The function of the expansion valve is to reduce the pressure of the
refrigerant before entering the evaporator.
The refrigerant's safety properties :
- unflamable
- nontoxic
- does not react with air and materials
- Cheap and easy production
Most common types of refrigerants :
Freons : R11 , R12 , R22 , R134 , R502 , R717 , R404
ammonia : NH3
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