Carrier 16JA - Manual (Page 12)

16JA ABSORPTION CYCLE
Figure 6 illustrates the basic absorption flow
diagram. The evaporator-absorber section oper­
ates at an absolute pressure of 0.25 in. Hg. As
the cooling load passes thru the cooler, the re­
frigerant picks up heat and is vaporized (boiled)
at 40 F because of the low absolute pressure. The
vaporized refrigerant migrates to the absorber
section due to the strong affinity for water of the
lithium bromide solution.
As more refrigerant is absorbed by the solution
the absorption rate decreases necessitating re­
generation of the lithium bromide solution to a
more concentrated form to maintain machine ca­
pacity, To accomplish this, diluted solution in the
absorber is pumped thru the tube side of a shell
and tube heat exchanger where it picks up some
heat from the hot strong solution returning from
the generator. On leaving the heat exchanger the
now warmer weak solution enters the generator,
is heated to boiling and the refrigerant is boiled
out, becoming a strong solution again. This strong
solution leaves the generator and passes thru the
shell side of the heat exchanger losing some heat
to the weak solution passing thru the tube side.
Usage of the heat exchanger reduces total heat
quantity required.
The strong solution returns to the absorber
sprays and is then sprayed over the absorber tube
bundle where absorption of refrigerant com­
mences again.
NOTE: Solution flow from generator to ab­
sorber is the result of gravity and pressure
difference and not by a pump.
Refrigerant boiled out of solution in the gen­
erator condenses on the condenser water coils and
returns to the evaporator via the vapor condensate
line. Refrigerant flows into the evaporator sump,
where it is pumped to sprays over the evaporator
coils and the cycle is repeated.
Capacity Control - A steam control valve is used
to control capacity. This valve operates by a con­
troller which senses the temperature of the leav­
ing chilled water. When the temperature is at or
above the design point, the machine will beat full
load. At this condition the steam control valve is
wide open to reconcentrate the solution in the gen­
erator. As the chilled water temperature drops be­
low the design point, the steam will be throttled. At
no load conditions the steam valve will be closed.
Manufacturer reserves the right to change any product specifications without notice
Tab 15 16JA-1SO New 1-68 Code MA Catalog No. 531-642