Refrigeration System - Kubota B1830 Workshop Manual

B1830,B2230,B2530,B3030, WSM

2. REFRIGERATION SYSTEM

(1) Heater Core
(2) Heat Sensitive Tube
(3) Compressor
(4) Evaporator
(5) Blower Motor
(6) Engine Cooling Fan
1. The gaseous refrigerant pass through the evaporator (4) and the compressor (3) at approx. 1.47 MPa (15 kgf/cm
213 psi) and is also raised in temperature to approx. 70 °C (158 °F) before being delivered to the condenser (11).
2. The gaseous refrigerant is cooled down through the condenser (11) to approx. 50 °C (122 °F) and delivered to
the receiver (10) in the liquid state.
At this time, heat removed from the cabin interior is extracted by means of the condenser (11).
3. The liquid refrigerant is collected in the receiver (10) for a certain period. At this time moisture is 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 (7)
into the evaporator (4), as if it were distributed by an atomizer. Thus, the refrigerant is reduced in both pressure
and temperature, and to ease evaporation.
5. The refrigerant vigorously evaporates at 0 °C (32 °F), taking heat from the surface of the pipes in the evaporator
(4).
6. At this time, warm air in a cabin is drawn into the evaporator (4) by the blower motor and is passed over those
pipes, transferring its heat to the refrigerant for evaporation. The cooled air is then distributed to the cabin and the
heat in the cabin is taken by the evaporator.
(Reference)
• Since warm air in the 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 (4) after having performed the cooling action is returned to the
compressor (3), 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 (1). In doing so, the air temperature can be adjusted to a comfortable level.
(7) Expansion Valve
(8) Pressure Switch
(9) Desiccant
(10) Receiver
(11) Condenser
10-M10
A: Cold Air
B: Low Pressure, Low
Temperature Gas and
Liquid Mist
D: Cabin Interior Air
E: High Pressure, High
Temperature Gas
CABIN
F: Hot Air
G: Liquid
(a) Refrigerant Flow
(b) Water Flow
9Y1210003CAM0011US0
KiSC issued 05, 2012 A
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