Evaporator; Heater Core - Kubota KX080-3 Workshop Manual

WSM KX080-3 Mechanism
i. Evaporator
The purpose of evaporator (2) is just opposite to
that of the condenser. The state of refrigerant
immediately after the expansion valve (4) is
100% liquid. As soon as the liquid pressure
drops, it starts to boil, and in doing so, absorbs
heat. This heat is removed from the air passing
over the cooling fins of the evaporator and
causes the air to cool.
If too much refrigerant is sent into the evaporator,
it will not boil away so easily. Also, the evaporator
filled with liquid refrigerant eliminates a place for
the refrigerant to properly vaporize, which is nec-
essary in order to take on heat. A flooding condi-
tion of the evaporator will allow an excess of
liquid refrigerant to leave the evaporator and may
cause serious damage to the compressor.
If too little refrigerant is sent into the evaporator,
again the evaporator will not cool because the
refrigerant will vaporize, or boil off, long before it
passes through the evaporator.
Refrigerant properly metered into the evapora-
tor should allow for 100% liquid just after the
expansion valve, and 100% gas at the outlet.
(1) Pressure Switch

(2) Evaporator

(3) Capillary Tube
(4) Expansion Valve
j. Heater core
(1)
(5) Thermostat
(6) Fin
(7) Tube
VI-M-19
(2)
The heater-source of heater utilizes coolant which
becomes high temperature by heat of engine.
The inlet port heater core is connected to the
delivery side of engine water pump by a rubber
hose, and the water valve is installed on the inlet
port of heater core.
Also, the outlet port of heater core is connected to
the engine cylinder block.
The heater core (1) is one of the heat exchangers
like evaporator or condenser, and heat is
exchanged between heated coolant passing
through the core and air in the cabin or fresh out-
door air. Thus, air is heated.

(1) Heater Core

VI Air Conditioner
(4)