LG Multi V PRHR033 Installation Manual page 52

52
Maintenance of plate type heat exchanger
As the scales are created in the panel heat exchanger, its efficiency
may decrease or damage may occur due to winter-sowing due to the
decrease in its flow.
Due to this reason, regular maintenance is necessary so that the scales
shouldn't be created.
1
Before the season of use, check below points.(Once a year)
1) Inspection on water quality to check if this is within the standard
condition.
2) Clean the strainer.
3) Check if the flow is appropriate.
4) Check if the operation environment is appropriate.(Pressure,
flow, output temperature)
2
Below procedure should be abided by in order to clean the panel
heat exchanger. (Once every 5 years)
1) Check if the service port is equipped with the water pipe in order
to clean the chemical solution.
5 % diluted formic acid, citric acid, oxalic acid, acetate acid,
phosphoric acid and etc. are appropriate for the chemical solution
for wiping out the scales.(Hydrochloric acid, sulphuric acid, nitric
acid and etc. shouldn't be used due to its corrosion.)
2) Be sure to check if the gate valve of inflow/outflow pipe and the
valve for outflow pipe are properly closed when cleaning.
3) Connect the water pipe for cleaning with the chemical solvent
through the service plug of the pipe and fill up the panel heat
exchanger with 50 °C ~ 60 °C (122 °F ~ 140 °F) of cleaning
solvent and circulate it with the pump for 2~5 hours. The
circulation time may depend on the temperature of the cleaning
solvent or the creation of the scales. Therefore, observe change
in the color of the chemical solvent to set the circulation time for
removing the scales.
4) After the circulation of the solvent, extract the solvent inside of
the panel heat exchanger and fill up 1 ~ 2 % of NaOH or
NaHCO3 and then, circulate it for 15 ~ 20 minutes to neutralize
the heat exchanger.
5) Once the neutralization is completed, clean the inside of the
panel heat exchanger with clean water.
Measure the water Ph to check if the chemical solvent is properly
removed or not.
6) When using a different kind of chemical solvent in the market, be
sure to check if there is any corrosive action to stainless or
copper in advance or not.
7) For details on the cleaning chemical solvent, be sure to consult
the specialists of the related corporation.
3
After cleaning, operate the device to see if it works properly once
again.
Gate valve(locked) Gate valve(locked)
Service plug
Strainer
Outflow water
valve(locked)
[Cleaning the panel heat exchanger]
Hose
Screening net
Water-cooling
type Multi V
Pump
Daily check/management
1
Water quality control
The plate type heat exchanger is not structured to be disassembled,
cleaned or replaced with parts. To prevent corrosion or scaling on
the plate type heat exchanger, special care must be taken to control
the water quality. Water quality must satisfy the minimum criteria
of the reference water quality items. When
anti-corrosion agent or corrosion inhibitor is added, the substance
must not have any corrosive effect on stainless steel and copper.
Even if the circulating water is not contaminated by the external air,
it is recommended to empty the water flowing in the pipe and to
resupply the water.
2
Flow rate control
If the flow rate is insufficient, it can cause freezing on the plate type
heat exchanger. Check whether the strainer is clogged or whether
the pipe is filled with air and then check the temperature and
pressure difference of the inlet and outlet pipe to check whether
the flow rate is insufficient. If the temperature and pressure
difference is above the appropriate level, it means that the flow rate
is reduced. In this case, the operation must immediately be stopped
and re-operated when the root cause is resolved. (*If air is trapped
in the pipe, the air must be purged. Air inside the water pipe
interferes with the circulation of the heat water supply and can
cause insufficient flow rate or freezing.)
3
Brine density management
When using the brine (Anti-freeze) in the heat water supply,
designated type and density must be used. Calcium chloride brine
can cause corrosion on the plate type heat exchanger and must not
be used. If the anti-freeze liquid is left as is, it absorbs the moisture
from the air to cause a drop in the density, leading to freezing of
plate type heat exchanger. Therefore minimize the contact surface
with the atmosphere and periodically measure the density of the
brine to supplement the brine as needed to maintain the density.
Maintenance/Repair checklist
Period (Year)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Checkpoint
Product operating
● ● ● ● ● ● ● ● ● ● ● ● ● ● ●
condition
Heat exchanger
cleaning (Wash)
● ● ● ● ● ● ● ● ● ● ● ● ● ● ●
Strainer cleaning
● ● ● ● ● ● ● ● ● ● ● ● ● ● ●
Water quality check
Refrigerant leakage
●
check
Indoor unit filter
● ● ● ● ● ● ● ● ● ● ● ● ● ● ●
cleaning
CAUTION
!
• The above checklist is set based on the minimum period and
more frequent checking can be required depending on the
operating condition/water quality condition.
• When cleaning the heat exchanger, make sure to take parts out
or lock the value so that chemical detergent does not penetrate
into the pressure gauge etc.
• When cleaning the heat exchanger, check the connecting part of
the water pipes prior to cleaning so that the chemical detergent
does not leak.
• After sufficiently mixing the chemical detergent with water, start
cleaning.
• Cleaning the heat exchanger is easier at the initial stage and
becomes difficult after the scaling has accumulated.
• In areas where the water quality is poor, cleaning is required
periodically. Because chemical detergent has strong acidity, it
must be washed off thoroughly with water.
• To check whether it is cleaned well inside, remove the hose and
check the inside.
• Purge the air to remove any air inside the water pipe.
• After checking, always check whether the heat water supply is
flowing normally flowing before operating the product.
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