Kubota M6800S Workshop Manual page 563

M6800 · M6800S · M8200 · M9000, WSM
[3] REFRIGERATION SYSTEM
(1) Heat Sensitizing Tube
(2) Expansion Valve
(3) Evaporator
(4) Blower Motor
(5) Compressor
(6) Engine Cooling Fan
The refrigerant cycle of air conditioning system is as follows.
1. The gaseous refrigerant evaporated through the evaporator (3) is compressed in the compressor (5) to approx.
2
1.47 MPa (15 kgf/cm
condenser (7).
2. The gaseous refrigerant is cooled down through the condenser (7) to approx. 50 °C (122 °F) and delivered to the
receiver (8) in the liquid state.
At this time, heat removed from the cabin interior is extracted by means of the condenser (7).
3. The liquid refrigerant is collected in the receiver (8) for a certain period. At this time moisture are removed from
the refrigerant by desiccant (9).
4. The liquid refrigerant after removing moisture and dust is jetted out of the small hole of the expansion valve (2) into
the evaporator (3) as if it were distributed by an atomizer. Thus, the refrigerant is reduced in both pressure and
temperature, and becomes easy to evaporate.
5. The refrigerant evaporates at 0 °C (32 °F) vigorously, taking heat from the surface of the pipes in the evaporator (3).
6. At this time, warm air in a cabin is drawn into the evaporator (3) by the blower motor and is passed over those
pipes, transferring its heat to the refrigerant for evaporation. The air thus cooled is distributed to the cabin. (That
is heat in a cabin is taken by the evaporator.)
(Reference)
• Since warm air in a cabin is cooled suddenly, water in the air is liquefied and removed, which means
dehumidification is also performed.
7. The gaseous refrigerant from the evaporator (3) after having performed the cooling action is returned to the
compressor (5), and is compressed to liquefy it (high pressure and high temperature). This cycle is repeated.
8. The air coming from the evaporator is fed to the air mixing doors, by which part of the air is introduced into the
heater core (11). In doing so, the air temperature can be adjusted to a comfortable level. The air mixing doors are
controlled through the cable connected with the control panel.
(7) Condenser
(8) Receiver
(9) Desiccant
(10) Pressure Switch
(11) Heater Core
(12) Water Valve
, 213 psi) and is also raised in temperature to approx. 70 °C (158 °F) and delivered to the
(a) Cold Air
(b) Low Pressure, Low
Temperature Mist
(c) Cabin Interior Air
(d) Cabin Interior Air
10-M37
CABIN
(e) High Pressure, High
Temperature Gas
(f) Hot Air
(g) Liquid
KiSC issued 03, 2008 A