Achieving Net Zero: A Reliability Engineer’s Top 10 List

Drew D. Troyer, CRE, CEM

Principal Director

Accenture Industry X

Most organisations in the mining industry have set goals for reducing their carbon and greenhouse gas (GHG) footprints. Most have instituted a goal to achieve “net zero carbon” by some specified date (e.g., 2050). The goal is clear, but the pathway toward achieving that goal is often dark, hazy, confusing, and, candidly, a little bit scary. The truth is that there is no one thing that will enable mining companies to achieve their net zero objectives. Rather, success depends upon the cumulative effect of every functional team in the organisation contributing – including asset managers, reliability engineers, operators, and maintainers of physical equipment assets. For reliability engineers, their most notable contribution is to enable energy efficiency. The US Department of Energy (DOE) estimates that miners can reduce their energy consumption by 20% by implementing technologies and best practices that already exist. The great thing is that in addition to reducing carbon impact, the money saved on energy goes straight to the firm’s bottom line and wear and tear on the equipment is typically reduced – an all-around win.

In our quest to achieve net zero, there are elements that reside in the reliability engineer’s circle of awareness, circle of influence, and circle of control (Figure 1). The circle of awareness includes those items for which the reliability engineer can’t actively participate. For example, as reliability engineers, we’re not going to solve nuclear fusion, address the fact that solar and wind power aren’t dispatchable sources of energy, design new renewable energy sources, or even design machines that employ renewable energy. We should remain aware of these technological changes, but we’re not going to actively participate.

However, as we move into our circle of influence, we take a more participative role. For example, we can provide feedback about the potential energy savings associated with sustaining or expansive capital projects. We can evaluate the benefits of utilising high efficiency motors, employing variable frequency/speed drives (VFD/VSD), designing pipework to reduce frictional losses with larger diameter and minimising twists and turns, and digitally enabling our machine for improved monitoring and process control. The design of a process or machine represents its genetic code or DNA. It’s hard to overcome bad DNA. Careful analysis of current conditions enables the reliability engineer to advise and influence more sustainable design of processes and equipment. The circle of control represents those actions where the reliability engineer can have an immediate impact on energy consumption and, as a result, contribute to achieving the organisation’s net-zero goals. Let’s explore our Top 10 list in more detail.

The Reliability Engineer’s Circle of Control in Achieving Net Zero

Industrial process employ energy in a variety of forms to extract, process, and or transform materials. Energy efficiency focuses on the efficient conversion of energy from one form to another and to ensure that the energy is smoothly transferred along its intended pathway – whether it’s thermal, mechanical, or electrical. As reliability engineers, we can minimise conversion losses associated with combustion, reduce parasitic mechanical frictional losses and electrical heating losses, reduce leaks and fugitive emissions by carefully properly operating, carefully monitoring, and proactively maintaining our equipment assets. Let’s dig deeper into our Top 10 list of things a reliability engineer can do to contribute to our net zero goal.

1.     Maintain Efficient Combustion in Your Engines - Diesel fuel contains about 38 Megajoules (MJ) of energy per litre. Under ideal conditions, about 17 MJs per litre make it to the drive train for modern, high-efficiency engines. If combustion isn’t properly managed, that efficiency can fall sharply without the operator noticing it. Air-to-fuel mixture, fuel quality and cleanliness, and fuel injector system performance are among the major variables on which to focus to maximise combustion efficiency. Dropping from 45% to 33% increases fuel consumption (and cost) and associated GHG emissions by nearly 40%! Employ oil analysis to detect abnormal combustion conditions and supplement that with fuel analysis to ensure that you're employing top-quality fuel that’s in top condition.

2.     Reduce Mechanical Frictional Losses - Parasitic friction caused by poor lubrication selection, application, analysis, and management. Poor lubrication practices routinely result in a 2.5-7.5% energy waste loss in the form of frictional heating. In extreme cases, the energy waste is higher. Wrong, degraded, contaminated, and/or insufficient lubricant also accelerates equipment wear and tear. Oil analysis and ultrasonic acoustic monitoring devices are brilliant for providing feedback about the lubricant and lubrication effectiveness. Online ultrasonic sensors coupled with automatic grease systems can enable “smart and automated” condition-based greasing in addition to providing good feedback about lubrication effectiveness and machine health.

3.     Reduce Vibrational Losses - Mechanical vibration caused by loose fasteners, misalignment, mechanical unbalance, resonance, etc. Machines that are shaky and noisy utilise 10% or more energy than the same machines that run cool and quiet. Vibration is also a very destructive force that increases wear and tear on the equipment. Monitor vibration routinely with online or walk-around vibration and ultrasonic analysis equipment to ensure that your machines are aligned, mechanically balanced, and properly fastened down to eliminate looseness. Rough shaft alignment practices with a straight edge, for example, have been shown to increase energy consumption by 10% or more compared to precision laser alignment. Vibration analysis performed with portable or online equipment can very easily enable to you ensure that your machines are running smoothly. Electrical signature analysis (ESA) also reveals mechanically induced energy inefficiencies and can be performed with portable equipment or set up for online monitoring.

4.     Reduce V-Belt Slippage - Poor v-belt installation, tensioning, and pulley alignment lead to excessive slippage. The author has observed belt slip as high as 16% on secondary crushers in the mining industry. Belt slippage wastes energy, reduces throughput, and increases wear and tear on the equipment. Belts have been known to catch fire under these conditions, exacerbating the risk. A simple strobe light will enable you to determine the speed of each pulley and calculate your slippage losses. Then, take action to ensure that your belts are properly installed, properly aligned, properly tensioned, and, of course, in great condition.

5.     Detect and Eliminate Fugitive Emissions - Fugitive emissions (leaks) of pressurised/compressed fluids. For example, it is common for compressed air systems to leak 20% or more by volume and leakage rates as high as 33% aren’t uncommon. Parasitic leaks of pressurised/compressed fluids pour wasted energy into the atmosphere. In some instances, those emissions carry health, safety, and other environmental risks. Natural gas leaks, for example, are very toxic and very flammable. And, one ton of methane, the primary component of natural gas equals 35-100 tons of CO2 as a GHG, depending upon the timescale. 

6.     Minimise Electrical Heating Losses - Electrical heating (I2R) losses due to undersized electrical circuits, mechanically or thermally degraded circuits, and/or improperly fastened connections (e.g., wire to connector, connector to terminal, bus bars, etc.). These losses can result in significant parasitic electrical energy losses of as much as 10% or more. Electrical heating leads to oxidation and carbonisation degradation of conductors, which further increases resistivity losses. A 10°C increase in temperature will reduce an electric motor’s winding insulation life by 50%. An increase of 20°C cuts the insulation life by 75%. Electric circuit analysis will quickly identify excessive heating. Infrared cameras are easy to use and quickly reveal electrical heating.

7.     Manage Electrical Power Quality - Poor energy quality management, especially harmonic distortion, and reactive loads lead to a great deal of heat generation. Voltage hand current harmonic distortion can easily increase energy consumption by 10% or more. New filters for reducing harmonic distortion combined with electrical signature analysis (ESA) can help you easily identify and recover these losses. In addition to energy waste, harmonic distortion, reactive loads, and other power quality issues cause damage to electric motors and other electrical equipment.

8.     Minimise Electrical Unbalance - Failure to manage phase-to-phase voltage, current, resistive, and inductive balance in three-phase electric motors results in a tremendous amount of energy being converted to heat. It also results in a functional derate of the motor. As a rule of thumb, current unbalance is 6-10 times the voltage unbalance. A 3% phase-to-phase voltage imbalance produces an 18-30% increase in current draw. On average, the motor will run about 18% hotter than the same motor that’s electrically balanced to high precision. Electrical unbalance is potentially very damaging to electric motors. Electrical Signature Analysis will quickly identify phase-to-phase electrical unbalance and it can be performed as a periodic test or continuously on-line.

9.     Control Your Operations – The way we start up, shut down, adjust, and otherwise operate the equipment can dramatically impact energy consumption. Operating equipment correctly is essential. Fortunately, technology makes process monitoring and control cheap and easy. The manner in which operations are controlled is less generalizable than the other items on this list. It is process and equipment-type dependent, but the basics of controlling and monitoring, temperatures, flows, pressures, etc., nearly always come into play.

10. Management By Walking Around (MBWA) – While less direct and objective than the other nine items on this list, the reliability engineer who is actively looking and listening to his or her equipment, the operators who run it, and the maintainers who repair and attend to it, are better able to identify opportunities that the deskbound engineer misses. The digital age has put a lot of data at our fingertips. But data and information aren’t the same things. The engineer who practices MBWA is in a better position to turn data into actionable information and is positioned to pick up on things our sensors and other digital enablers can’t. Never underestimate the value of an engaged team.

Looking at this list, it’s easy to see how we can substantially reduce energy consumption and associated greenhouse gas (GHG) by proactively applying some first principles of reliability engineering that are relatively easy to execute. Achieving the 20% energy savings as estimated by the US Department of Energy (DOE) is often easily within reach and enables you to substantially contribute to your organisation’s net-zero goals and save some money and extend your equipment life to boot.