LARTC 2026
Data-driven fired heater performance recovery
Ella Boyden Integrated Global Services
Rising fuel costs, decarbonisation targets, and pressure to maximise asset utilisa- tion are driving refinery and petrochemical operators to examine every opportunity to improve fired heater efficiency. While opti- misation efforts often focus on burners, combustion control, and process tuning, a significant recurring source of energy loss is fouling in the convection section. Deposits accumulate on finned and bare tubes, reducing heat transfer from the flue gas to the process. The heater continues to operate, but less heat is recovered, stack temperatures increase, and additional fuel is required to maintain process duty. Since this deterioration occurs over extended operating periods, it is often accepted as normal rather than recognised as recover- able performance loss. For refinery and petrochemical opera- tors, these incremental losses can become significant. Internal thermal modelling dem- onstrates that a representative furnace experiencing a moderate 50°C increase in stack temperature can lose approximately 2-3% thermal efficiency, increasing fuel demand by around 4 MW. Across a five- furnace operation, this equates to almost $1.9 million in additional annual fuel costs before considering production impacts or increased emissions. Moving from maintenance to performance recovery Historically, convection section cleaning has been treated as a maintenance activ- ity, typically scheduled during turnarounds or undertaken when fouling becomes vis- ually apparent. However, this approach does not necessarily align intervention with the point at which energy losses jus- tify cleaning. Instead, an increasing number of oper- ators are adopting a performance-based strategy. By comparing measured oper- ating conditions with the original design parameters, thermal evaluations can quan- tify efficiency losses, estimate recoverable fuel savings, and identify the optimal point for intervention. Stack temperature, fuel consumption, and heat recovery become measurable indicators of economic per- formance rather than simple operating parameters. This approach shifts convection section cleaning from a reactive maintenance task to an evidence-based performance recov- ery programme. limitations of conventional cleaning Convection banks present unique mainte- nance challenges. Closely spaced finned tube arrangements create narrow flow passages where combustion ash and par- ticulate deposits accumulate over time. Conventional cleaning methods often struggle to reach deposits deep within tube banks, leaving residual fouling that continues to restrict heat transfer. Incomplete cleaning means that while visual improvements may be achieved, thermal performance is not always fully restored. Consequently, the true value
DID you know? Measured thermal performance, not visible fouling, should determine cleaning intervals
Performance recovery following convection section cleaning
Performance indicator Before cleaning
After cleaning -130°C (-234°F)
Stack temperature Thermal efficiency Fuel consumption
Elevated Baseline Baseline
+7.2%
-2.2 MW (7.5 MMBtu/h)
Figure 1 Remote robotic cleaning of convection tube banks enables full access to complex tube geometries while eliminating the need for confined-space entry
Annual operating cost
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$900,000 saving
Cleaning coverage
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100% accessible tubes Zero incidents
Safety performance
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and reduced operating costs, improve- ments in fired heater performance can deliver significant financial returns without major capital investment. The key lesson is that fouling should no longer be assessed solely by visual inspection or fixed maintenance inter- vals. Instead, operators should monitor thermal performance indicators, quantify the value at risk, and schedule cleaning when measurable efficiency losses justify intervention. Conclusion As refining and petrochemical facili- ties continue to operate under increasing commercial and environmental pressure, improving fired heater efficiency repre- sents one of the most accessible opportu- nities to reduce energy consumption and operating costs. The remotely operated vehicle (ROV) cleaning case study demonstrates that combining thermal performance evalua- tion with high-coverage robotic cleaning can recover substantial efficiency losses, delivering measurable reductions in stack temperature, fuel consumption, and oper- ating costs while improving maintenance safety. Ultimately, convection section clean- ing should be viewed not simply as a maintenance activity but as a repeatable performance-recovery strategy. By basing intervention on measured thermal perfor- mance rather than elapsed operating time, refinery operators can make evidence- based decisions that maximise energy recovery, reduce emissions, and improve long-term asset profitability. Table 1 Measured steam cracker perfor- mance following robotic convection section cleaning
Figure 2 Convection section finned tubes before and after robotic cleaning. Removal of fouling restored heat-transfer surfaces and improved convective duty
economic justification for cleaning before work commenced. A remotely operated high-pressure water-cleaning system was deployed to clean four convection tube coils, each approximately 10 metres long. Cleaning was performed from multiple access points, enabling complete coverage of all accessible tubes and eliminating the need for confined-space entry. High-definition remote monitoring enabled the verifica- tion of cleaning progress throughout the operation. Beyond the direct energy savings, restoring convection section heat recov- ery improved radiant inlet temperatures, reduced radiant heat flux requirements, and created conditions expected to sup- port improved operating stability and longer run lengths between maintenance interventions. Wider implications for refinery operators Although this project was completed at a Brazilian ethylene facility, the engineering principles apply equally to refinery-fired heaters. Whether processing crude oil, vacuum gas oil, reformer feed, or petrochemical feedstocks, fired heaters rely on efficient recovery of waste heat within the con- vection section. Any deterioration in this heat recovery increases firing duty, raises stack losses, and reduces overall thermal efficiency. For operators pursuing lower emissions
of recovered heat transfer may remain unrealised. Robotic cleaning systems have been developed to overcome these access limi- tations. Remotely operated equipment can navigate complex tube geometries, clean from multiple access points, and elimi- nate the need for personnel to enter con- fined spaces during cleaning operations. Continuous visual monitoring also provides greater confidence that cleaning coverage has been achieved across all accessible surfaces. Steam Cracker case study demonstrates measurable performance recovery The benefits of this approach were demon- strated during a fired heater performance recovery project at a large olefin produc- tion facility in Brazil. Routine inspection identified significant fouling throughout the convection section, including deposits embedded between finned tubes, scale covering bare tubes, and increased accumulation in lower tube banks where particulate matter had set- tled. The fouling had progressively reduced heat transfer, increased fuel demand, and raised stack temperatures beyond normal operating expectations. Prior to the intervention, a thermal eval- uation predicted that restoring the cleanli- ness of the convection section would yield measurable improvements in thermal effi- ciency and fuel consumption. These pre- dictions established a clear technical and
Contact: ella.boyden@integratedglobal.com
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