Heat exchangers – equipment used to transfer heat from one fluid to another -- are at the heart of production of a host of chemicals, petrochemicals and oil products.
However, fouling in heat exchangers – the build-up of scaling, corrosion or other debris - is a critical issue that can affect not only the profitability but also the sustainability of plants in the oil and gas industries. Even single-digit percentage in efficiency due to fouling quickly add up, since every cut into production is a cut into profit, totaling up to thousands of dollars per day.
Despite this, asset health tends to be one of the lowest items on the priority list for many operators. It’s easy to see why. Heat exchangers occupy a similar space as a car’s transmission – so long as everything appears to be working, it’s out of sight and out of mind, with scheduled maintenance being the most attention they typically receive.
And yet, much like a car’s transmission, operators who have a heat exchanger fail on them will quickly understand how much time and money they could have saved by addressing its maintenance needs sooner. The real issue is finding the time and resources to monitor fouling more closely.
mCloud’s AssetCare solutions are ideal for this time-consuming task. By outfitting a plant with sensors to monitor a plethora of factors – such as temperature, density and pressure – we’re able to build a digital twin to track fouling in real time. Leveraging the digital twin enables the use of three key metrics to know when an exchanger needs attention:
Performance
This is determined by current heat transfer divided by heat transfer under initial or clean conditions. There are several ways to calculate the amount of heat transfer, such as measuring the flow rate of one of the fluids and the change in its temperature. For example, a hot water heater that warms 50 gallons of water from 68 degrees to 120 degrees Fahrenheit (20 to 46 degrees Celsius) takes an easily calculatable amount of energy. The best way to do this calculation depends on available sensors.
Once the heat transfer is determined, it can be compared to the design specifications or a first principles process simulator to determine how well the exchanger is working compared to when it was new.
Health Index
This index indicates the remaining useful life of a heat exchanger. This estimate is made through a full analysis of the state of heat transfer, flow rate, what the process needs to do and other elements to estimate the remaining useful life of the exchanger and, more generally, when a heat exchanger will no longer be able to carry out its expected functions.
Utilization
This metric looks at how much of the heat exchanger’s capacity is currently being used. For example, a plant may be working with an oversized exchanger and only need half its ability to transfer heat for the current operation. Utilization provides an indication of which exchangers might be close to being critical to plant operations. It’s important because a clean, high-functioning heat exchanger operating at close to capacity is more in need of attention than a fouled exchanger with plenty of spare capacity.
By combining these three metrics – with some extra help from data analysis via AI – mCloud can generate an asset health score for a given heat exchanger. This score is measured against expected values and can be updated as often as every few minutes.
Through this approach, we’re able to monitor performance on behalf of our customers while sparing their operators the impossible task of maintaining omniscience over all their assets. If we see any issues, such as a sharp and sudden fall in effectiveness overnight, a quick alert can spare the customer from imminent and costly unplanned downtime.
That’s one of the largest appeals of AssetCare for any operator: the move from scheduled maintenance to condition-based maintenance, a formerly unattainable approach that optimizes production, reduces energy costs, increases throughputs and slashes maintenance needs.
Operators who proactively adopt these technologies today will find themselves poised to lead the industry tomorrow. To learn how mCloud’s AssetCare can help you today, visit our website: https://www.mcloudcorp.com/assetcare.
