When a facility decides to improve energy efficiency, the instinct is often to target the most obvious problem and fix it. That’s understandable — but according to the Department of Energy’s process heating sourcebook, fixing individual components in isolation often misses a larger opportunity and can even produce misleading results.
The DOE Sourcebook recommends what it calls a systems approach: a top-down review of how all the components of a process heating system perform and interact together. The goal is to understand the whole before optimizing the parts.
What a Systems Approach Actually Looks Like
The sourcebook describes the systems approach as a process that starts with creating process flow diagrams — visual maps of how materials and energy move through the system. This gives engineers and facility managers a “bird’s-eye view” of the entire process and allows them to rank components by their efficiency impact.
Importantly, it also reveals how changing one component affects others. Here’s an example. tuning burners reduce energy use, but it will also make the gains from flue gas heat recovery somewhat smaller than they would have been before the burners were tuned. Without the systems perspective, you might over-estimate the benefit of the second improvement.
Start with the Data You Have
A systems approach requires data. Mapping energy flows through a system highlights the confidence in existing data and identifies what additional measurements are needed. In other words, the process of analyzing the system reveals gaps that need to be filled before improvements can be properly evaluated.
Analysis doesn’t have to be complicated. In many cases, it starts with temperature measurements at key surfaces, monitoring of exhaust gas composition, and basic tracking of fuel use per unit of output.
Individual Components Still Matter
The systems approach doesn’t replace component-level analysis — it informs it. After the top-down review identifies which components have the highest efficiency impact, those components are then analyzed in detail. The US Department of Energy sourcebook describes this as an iterative process: the component’s improved performance is fed back into the system model to determine true gains when interactions between components are taken into account.
Insulation is a good example of where this matters. Adding insulation to a furnace wall reduces surface heat loss. But it also changes the thermal environment inside the furnace, which may affect heat transfer to the product, which may affect how the control system responds. A complete analysis accounts for all of those effects.
When you’re ready to take stock of heat losses across your facility, UniTherm’s team can help you think through where removable insulation solutions apply — from plastics processing equipment to piping systems to exhaust components. A systems view often reveals insulation opportunities that aren’t obvious from looking at individual pieces of equipment.
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Source: U.S. DOE, Improving Process Heating System Performance: A Sourcebook for Industry (Third Edition), 2015.