ENGLISH
115
Yearly inspection
- Yearly inspection
Classification
Inspection items
Inspection method
Criteria
Motor
Motor Terminal fas-
ten bolt
Check the slackness
Check the loose
Loose terminal finishing state
Condenser
Chemical analysis
Water quality analysis
Water quality standard
Tubes condition
Check it at the operation record or
by opening the waterbox.
No pollution
Evaporator
Chemical analysis
Water quality analysis
Water quality standard
Tubes condition
Check it at the operation record or
by opening the waterbox.
No pollution
Oil and lubricant
Oil cooler cleaning
Clean by refrigerant
No corrosion or pollution should be pres-
ent
Ejector cleaning
Disassemble cleaning
No abnormality
Filter cleaning
Filter exchanging, Cleaning the
housing
No abnormality
Oil tank cleaning
Disassemble cleaning
No pollution
Oil Replacing
2000 hours or 1 year
Figure 93. Yearly inspection standard
<Water quality analysis>
The cooling water at the open circulation type cooling tower uses the evaporation latent heat to lower down the
water temperature and also recycles it.
At this time the water evaporates and the chloride ions in the water and the acid ions will increase. This will lead to
enrichment situation and eventually deteriorate the water quality.
Also, in the cooling tower, water and air are always in contact with each other and the contaminating material(auto-
mobile exhaust gas, sulfurous acid gas, dust, gas of chemical plants such as ammonia or petroleum gas, etc.) deterio-
rates the water quality even more.
These pollutant causes can corrode the pipe, scales adhered causes the tubes to have holes and lockouts which are
leading to a decreasing effect of heat exchanger.
Therefore, it may end to replacing the tubes, increased power cost, or the chiller failure.
Thus, cooling water quality must be maintained at a certain level.
Water quality analysis should be taken place periodically and if the results are out of the standards boundary(Table
23.), it must be replaced. At the beginning of the season and at the initial starting of the machine, water quality analy-
sis is inevitable.
To prevent the cooling water enrichment, certain amount of cooling water should be drained during the circulation
and then supplying fresh cooling water. Another way of water quality analysis would be using chemical handling.
<Tubes State>
If water corroded dirt is adhered or foreign substances are mixed in the tubes, resistance is increased which makes it
hard for the chiller to have a good efficiency. It also makes it easy to cause surge.
If sandy like solid materials are mixed in the cooling water, erosion or corrosion may occur at the entrance of the
tubes, therefore when cleaning the tubes make sure that you check the inner surface of it.
Install a filter at the inlet of the cooling water pipe. Generally, a cooling tower is used for the cooling water system,
but when using the subterranean water or the riparian water it is possible for the scales to be adhered easily due to
low quality of water compared to the chilled water.
