Condenser.

TM 55-1905-223-24-17

Condenser.

(1)

The condenser serves two important functions:

(a)

It removes the heat picked up by the refrigerant in the cooling coil.

(b)

It condenses the refrigerant vapor to a refrigerant liquid.

(2)

The heat removal and condensing processes take place by a water cooling process. The

refrigerant vapor is passed through an outer shell of the condenser tubes and cool seawater

passes through an inner shell, or tubing (FIGURE 1-4). The seawater supplied to the condenser

is at a lower temperature than the temperature of the refrigerant vapor. Heat from the refrigerant

is transferred to the seawater through the inner tubing walls. The seawater then carries the heat

from the condenser through a discharge or drain line. The condenser removes enough heat to

change the refrigerant from a vapor to a liquid.

Expansion Valve. FIGURE 1-5 illustrates the principle of both the expansion valve method and

the capillary tube method of metering the refrigerant flow.

NOTE

The self-contained air conditioning units use a capillary tube assembly in the place

of an expansion valve. However, the principle, or function, of supplying refrigerant

to the cooling coil is the same in both methods.

(1)

Expansion Valve Method. The expansion valve reduces the pressure of the refrigerant liquid,

and in doing so, it cools the liquid. Refrigerant enters the valve under pressure. As it passes

through a small valve port, it enters the low pressure area of the cooling coil. The valve port acts

as a metering device between a high pressure area (the condenser), and a low pressure area (the

cooling coil). As the pressure is reduced, the point at which the liquid becomes a vapor is also

reduced. Therefore, after the liquid refrigerant passes through the metering port in the expansion

valve, it begins to vaporize in the cooling coil because it is now in a low pressure area.

(2)

Capillary Tube Method (Self-Contained A/C Units). The principle, or function, of the capillary

tube method is the same as that of the expansion valve method. The basic difference in the two

methods is that the refrigerant is metered through a series of long, small diameter capillary

tubes instead of through a single, small valve port. (See FIGURE 1-5.)

NOTE

The number of capillary tubes will vary in different types of air conditioners.

1-17