Title: Meeting Today's Challenges: Essential Role of Energy Conservation

Energy conservation Energy efficiency achieved today, improves surely the existing OPM Operating Profit Margins. Why the energy conservation becomes essential in the industry now because this is generally low cost, less time pay back, instantly implementable in the existing utility as part of OPEX.

If we take the utility, macro view of the energy audit field study is okay to focus on what is the energy input and the output or the energy embedded in the output or in the exhaust areas. But micro view demands the energy professionals to look into the intermediate energy losses happening in each utility sub-system at the input, at the process and at the delivery of the utility system.

So condition monitoring of the energy influencing parameters of the existing utility sub systems will surely prompt the user to reduce the excess energy consumption in between. Here the user, the utility OEM and the process OEM /experts have to collectively work in sync to optimize the same. The case studies of utility in compressors, blowers in the various industry segments are discussed.

The compressed air user needs to be aware of the ambient air surrounding the compressor. The day-night & seasonal variation in the moisture in the ambient air at various Humidity levels from 50 % to 80 % is huge, almost double. So the compressor efficiency needs to be trended for each shift of the day as KW / CFM spread over months to arrive the average SEC – KW/CFM.

BEE checklist of energy saving in utilities is generic thumb rules only and is guidance only. The values of energy saving depends on the existing operating pattern. BEE Guide books gave guidance to us regarding Compressors, that “For every 250 mmWC pressure drop across suction path due to choked filters, the power consumption increases by about 2 %”

Our case study observations on the given compressor case study, shows choked air intake filter at 2700 Pascal, ie 270 mmWC showed Delivery Flow drop of 13 % The user faces de-rated compressor flow due to choked air intake filter. This 110 KW compressor recorded average KW/CFM at 0.20, instead of norms at 0.17

Compressor feels (faces) SAD Starved Air Delivery at suction instead of FAD Free Air Delivery. First step - ambient air suction needs Pascal monitoring in compressor Retrofit Two stage air pre-filtration Pre-filter daily cleanable inside & outside Daily Washable PU II stage pre-filter to reduce main air filter choke, this is called Tropicalizing of utilities. Compressed air header flow meter & Totalizer is a MUST to quantify energy losses at inlet & from machine. This can only give the average SEC–KW/CFM in trend measurements.

Fans & Blowers, the variable torque loads, MUST be operated with the VFD to achieve Appreciable Energy Savings on Optimizing the deliverable RPM, flow, and Static Pressure that is demanded by the load from the Process. In Varying Torque load Blower, Theory behind Input KW reduction due to reduction in power transmission Losses & matching the torque requirement between the supplied Motor Torque and the Demanded Torque in blower motors by the VFD. The case study clearly indicates that there is gap between the supply and demanded torques from motor to blower, variable torque load; Blowers need Lower Torque at lower speeds, that is utilized here for energy saving.

This is not only happening in Variable Torque loads but also in the Constant Torque loads like the CTC machines in the tea industry and ring frame in the textile mills as they consume more than 50 % KWH consumption in the above industries. So instead of replacing the motor first in these machines, we have to attack the intermediate visible losses in between motor and machine, vide the case studies. Let us revisit to the energy saving proposals we had given already & prioritize first.

• Monitor the energy consumption at Input, output & Exhaust sections.
• First step is try is to TRIM the input parameters to suit to process; this is always the LOWEST cost.
• Optimize the Intermediate Self-consumption in power transmission in sub systems.
• Try to restore to the name plate efficiency of the equipment by optimizing the above.
• After trying all possible zero / low cost measures on the existing equipment, then plan next.
• Many EE Utilities perform poorly due to wrong installation practices, look for commissioning reports.
• Retrofit the wetted parts of the existing machine / process systems to keep as Active working spare.
• Match the Auxiliary sub systems sizing and functioning to the average running load of main system.
• Next Replace with the latest Energy Efficient version with Increase in productivity and Decrease in the existing Energy consumption.
• When your equipments / process are ageing and deviating from the Best operated Norms, output production reduces & Exhaust increases. Higher the Exhaust, shows Input versus Output efficiency drops either in Specific Energy Consumption or Less Productivity.
• Motors –IE2, IE3, IE4 & IE5 / BLDC motors, replacement needed from IE1 versions.
• Replace motors Below 10 HP, more daily run hours, energy saving scope is above 10 %
• Pumps Efficiency varies from 30 to 80 % - study pumping system as a whole, not the pump only.
• Fans & Blowers as system efficiency varies from 30 to 70 % - study the Fan Performance curve.
• Compressors – 250 Watt per CFM to 150 Watt per CFM – in generation and air leakage to focus.

VFD needs to be made mandatory for all varying torque loads, so as to optimize and match.

Having inputted so much higher KWH / energy at the input, the KWH / energy losses are happening in between input and output. This focus on the intermediate energy losses will reduce / optimize the SEC Specific Energy consumption of the Auxiliary & utility sub systems and as well improve the output deliverables.