METI / ECCJ / ACE Training Program MTPEC05 (2006.08)

Energy-saving effect by 1 day-audit
(Average energy-saving rate by industry)

Case example of audit (1): Water supplying works

Problems:
l. Aeration fan is uncontrollable.
2. Fluidized bed incinerator is inefficient.

Improvement measures:
1. Aeration fan — It is inappropriate to use an inverter. (Investment in the inverter to control three units of aeration fans simultaneously so as to avoid wind pressure change is too costly.) The problem was solved by the combination of interval operations and the control of the number of units.

2. Increase the efficiency of fluidized bed incinerator by using regenerative burner
— A pair of burners, which are unified with a heat regenerator for preheating, burn alternately in a short cycle.
Effect: Power — 1,200MWh/year, Oil — 293kL/year, Total — 12.4% reduction

Case example of audit (2): Food manufacturing industry

Problems:
1. Operation standard for air conditioner is not clear.
2. Operation standard for compressor is not clear.
3. There is room for improved use of steam.

Improvement measures:
1. Increase the standard preset temperature by 1^oC.
2. Narrow the nighttime air conditioning area and extend the time.
3. Extend the ventilation (allowing fresh air enter, driving out foul air) interval.
4. Lower the discharge pressure of compressor by 0.098Mpa.
5. Stop the operation of two large compressors and install one small compressor for nighttime operation.
6. Decrease the revolution of the digester material feeder to stop the leakage of steam.
7. Decrease the number of boilers in operation (from 9 unit for night and day to 6 units during daytime and 2 units at night).
8. Decrease the blow volume of the boiler (in accordance with water uality).

Effect: Electric power — 681MWh/year, LPG — 96.7t/year Total — 16.6% reduction

Case example of audit (3): Petrochemical product manufacturing

Problems:
1. Refrigerator load is too large.
2. Heat is discharged from the water cooler in the rectifying system.
3. Four units of circulating pumps of thermal oil are in the condition of light load operation.

Improvement measures:
1. Increase the heat exchangers of refrigerator precooler to reduce the power consumption of the compressor.
2. Install more heat exchangers in the rectifying system to reduce the fuel gas consumption of the thermal oil heater.
3. Operate the thermal oil pump and heater, controlling the number of units and the temperature to match the load.

23/37
Next