ECCJ / Text for Training Courses / METI / Energy conservationin Japanese factory(2006.7) / Thailand

ECCJ / Text for Training Courses

Thailand

Example --- by utility audit "Boiler & Steam system" in Food industry

<Existing problems>

No steam drain traps are provided.
- Drain water is discharged onto the floor by opening valves slightly.
- No drain water is recovered.

<Improvements and estimated effects>

Installation of drain traps and drain recovery devices
Drain traps (15 A) are attached to all drainpipes. Drain water is recovered completely by means of a centralized piping system that leads to a recovery tank installed near the boiler room.
This increases the temperature of boiler feed water, allowing energy conservation.

Example "Compressor" in Manufacturing of precision machinery

--- by utility audit

<Existing problems>

A considerable amount of energy is being wasted. (The discharge pressure of the factory's compressors is too high. The factory has no system for controlling the number of compressors brought into operation according to load conditions. There is no receiver tank. Air is leaking from piping.)

Reduction in discharge pressure
The actual discharge pressure (0.68MPa) should be dropped to 0.58MPa. (required range is 0.45 to 0.5MPa ).
[Pressure reduction 0.1MPa is corresponding to 8% of electricity consumption.]
Control of the number of compressors brought into operation & installation of receiver tank
Currently, six compressors are turned on and off separately at their pressure settings. The number of compressors brought into operation should be controlled in accordance with load conditions. This will reduce power consumption, and cut down the maintenance cost.
[The receiver tank will reduce the pressure fluctuation caused by load change.]
Prevention of air leakage
The main stop valve of each unused air pipe is closed, as is the air valve of each non- operating machine.
[Generally, the air leakage is more than 10%, sometimes it reaches to 20% in factory. Total air leakage should be reduced less than 5% by proper maintenance.]

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