Hyundai HDFN-80-1400, Operation Instructions Manual, Page: 69 / 69

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3.5 Charging Procedure of Chemicals
(1) Li
2
CrO
4
(chromic acid lithium)
AT the service operation with 1/3 fuel consumption rate at full load, charge Li
2
CrO
4
diluted with
50 liters of refrigerant (pure water) gradually from the discharge service valve of the refrigerant
pump. The charging rate must be less than 5 liters/min. When completing the charge, open the
refrigerant bypass valve fully and transfer the Li
2
CrO
4
in the refrigerant line to the solution line at
the ordinary operation or the service operation.
(2) LiOH (Lithium hydroxide)
At the ordinary operation or the service operation, change LiOH diluted with 50 liters of
refrigerant (pure water) gradually from the service valve of concentrated solution at the outlet of
the low temperature heat exchanger. The charging rate must be less than 5 liters/min.
(3) HBr
Charge HBr in the same as above (2).
3.6 Subsequent Treatment
After charging the chemicals, operate the chiller-heater for 30 minutes or more. Then, check if the
specific gravity of refrigerant is below 1.01 and sample the dilute solution. Analyze the sampled
solution to confirm each charged amount of the chemicals is appropriate.
3.7 Caution for Handling the Chemicals
Be careful not to touch Li
2
CrO
4
with hands or not to put it in the mouth, because Cr in Li
2
CrO
4
is one
of the toxic heavy metals. Especially, be careful not to put LiOH in the eyes.
4. Spill-over
As the cooling load changes, both the refrigerant level of the evaporator and the solution level of the
absorber also change. Fig. 10 (A) and (B) show the changes in those liquid levels when the cooling
load changes.
Fig. 10 (A) shows each liquid level at low load, where the solution level of the absorber is high
because most of refrigerant dissolves in the solution and on the contrary, the refrigerant level is low.
While, Fig. 10 (B) shows each liquid level at full load, where the refrigerant level is high because most
of the refrigerant is separated from the solution and the solution level is low.
When the actual cooling load exceeds the rating full load of the chiller-heater, the refrigerant level
goes up and the refrigerant overflows into the absorber from the drain pipe called “spill-over pipe”
which is installed at the upper portion of the evaporator pan so that the solution may not be
concentrated excessively to ensure safe operation of the chiller-heater. The phenomenon that
refrigerant overflows is called “spill-over”. Whether refrigerant is overflowing from the evaporator can
be detected through the sight glass for the absorber since the edge of the spill-over pipe is located
near the sight glass.
In addition, when the solution is mixed with considerable amount of refrigerant, spill-over may occur
even when the cooling does not reach the full load of the chiller-heater. In such a case, the refrigerant
must be generated.