What we do not measure cannot be controlled. Utility flows should be measured accurately to have precise trends in energy consumption.
In most plants, steam accounts for about 40% of the utility costs with the balance being shared between electricity and water. Monitoring the utility streams allows one to be aware of deviations in the consumptions. This allows controlling the deviation the moment it occurs.
Often in many industries the utilities go unmonitored. There is no accurate reading available for daily fuel consumption and daily steam consumption from the boiler. At many locations, the plants measure either of these parameters and derive the other by multiplying by a fixed multiplier.
The results obtained by such a method are very misleading because the boiler efficiency or steam to fuel ratio obtained will always remain constant, irrespective of an actual fall in the working efficiency of the boiler.
Similar case applied to compressors generating compressed air or other utility generators.
- A minor change in S: F from say 13.5 to 13.25 translates into a 1.85% variation in fuel consumption.
- Every 20 degC deviation from optimum flue gas temperatures increases the fuel consumption by 1%
The table below presents the minimum parameters that should be monitored on an hourly basis for the following utility generators