technical NOTES

12.5 Life Cycle Analysis Summary of BF Fans >11KW on VVVFD Concept

S. N. Particulars Conventional System VVVFD Concept

V Compressed air saving No yes

3 System Installation & Commissioning

I System Installation & Commissioning Time Large time required, as more hardware’s in the system

Less time required,

as less hardware’s in

the system

4 Operation & Maintenance

I System reliability Less Efficient compare to VVVFD

More Efficient

System, 100%

Dependency on

Drive

Ii System Hardware More Hardware’s with the system Compare to VVVFD

L e s s H a r d w a r e ’ s

with the system

Compare to

conventional system

Iii Breakdown probabilities High due to Mechanical damper

Less compare

to Conventional

system

vi System Further optimisation margin Not possible with conventional system Possible with VVVFD System

S. N. Particulars Unit Return

1 Investment against VVVFD concept Rs in lacs 26.37

2 Investment against conventional concept with damp-er cost Rs in lacs 28.80

3 Less capex investment with VVVFD concept Rs in lacs -2.43

4 Annual benefit against in energy saving due to VVVFD considering approx. 10 % speed reduction Rs in lacs 59.7

12.6 Conclusion & Recommendation:
Based on the above comparison, initial investment is less in the VVVFD concept
compare to Conventional system & Additional gain of Energy Saving during
operating on 90% speed, it is strongly recommended to consider VVVFD drive
for all Bag Filter fans.

We should optimize motor kW rating with respect to VVVFD drives during designing
phase.