TM 5-3805-291-23-1
THEORY OF OPERATION - CONTINUED
0003 00
AIR CONDITIONING SYSTEM - CONTINUED
Evaporator Coil
0003 00
427-C2003
1.
The evaporator receives liquid refrigerant from the orifice tube assembly. The liquid refrigerant that is received by the
evaporator has low pressure and low temperature. Since the pressure of the liquid refrigerant is low, the temperature of
saturation of the refrigerant is low. At the temperature of saturation, the refrigerant changes from a liquid into a vapor.
The temperature of saturation of a fluid increases when the pressure of a fluid increases.
2.
The evaporator coil is exposed to the air inside of the cab. The heat from the air inside of the cab is absorbed by the
evaporator. The evaporator transfers the heat to the refrigerant. The amount of heat required to reach the temperature of
saturation is called the latent heat of vaporization. When this heat is absorbed by the refrigerant, the temperature of the
refrigerant will reach the temperature of saturation. The refrigerant will change from a liquid into a vapor. The vapor-
ized refrigerant will leave the evaporator. The vaporized refrigerant will carry away heat from the cab. The vaporized
refrigerant will return to the compressor when the refrigerant leaves the evaporator. This process is repeated continu-
ously.
END OF WORK PACKAGE
0003 00-187/(0003 00-188 Blank)
