47.107
Figure 10-17.-Miscellaneous ventilation fans: A. Centrifugal fan. B. Portable axial fan.
MECHANICAL COOLING EQUIPMENT
Almost all working and living spaces on newer
ships are air conditioned. The equipment used on these
ships was carefully tested to see which types would best
dehumidify and cool ship compartments. Two basic
types of equipment have been found most effective and
are now in general use. They are chilled water
circulating systems and self-contained air conditioners.
CHILLED WATER CIRCULATING
SYSTEMS
TWO basic types of chilled water air-conditioning
systems are now in use. They are a vapor compression
unit and a lithium bromide absorption unit. In the vapor
compression unit, the primary refrigerant cools the
secondary refrigerant (chilled water) that is used to cool
the spaces. This type uses the vapor compression cycle
and R-11 or R-114 as the primary refrigerant. The type
of primary refrigerant depends on the size and type of
compressor. The lithium bromide unit operates on the
absorption cycle and uses water as the primary
refrigerant. Lithium bromide is used as an absorbent.
Vapor compression plants are used in most ships.
However, lithium bromide plants are used in submarines
because they require no compression, which means a
quieter operation.
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