For projects utilizing Tube Tech by Integrated Global Services (IGS), a site visit is made to complete an inspection of the convection section and to collect data so that an evaluation can be conducted.
The evaluation determines the baseline operating conditions and estimates the potential project scope and expected benefits. The IGS Tube Tech cleaning technology allows for more than 90% of all the tube and fin surface area to be treated, unlike other more conventional methods that reach only 20-40% of the tube surfaces, depending on configuration.
The evaluation is based on calculating the external fouling-resistance factor for each bundle in the convection section based on the process data. The factors will be relieved by cleaning and a further evaluation will determine the post-cleaning performance, based on a constant processing duty, for example.
A balanced heat distribution between sections is also crucial in coking-sensitive services. Keeping the convection section surface clean not only helps save fuel and increase steam generation, but also positively influences the steam-cracking process.
In many cases, the stack temperature is determined to be a key performance indicator to identify and quantify the benefit after cleaning. After almost two years of using IGS technology, a client reported a slight elevation in stack temperature of 10°C and a stable efficiency increase of 1.5%. Their next clean is anticipated to take place in six years to reinstate the efficiency.
An Egyptian oil refinery recently faced challenges with its Hydrogen Generation Unit (HGU). Issues such as hot spots on catalyst tubes, aging reformer tubes and outlet systems and reduced hydrogen demand have led to the unit operating at a reduced capacity. To address these bottlenecks and evaluate the unit’s current status, a comprehensive assessment and debottleneck study was conducted by the OEM.
One significant finding of the study revealed the underperformance of the convection coils, which hindered the unit from achieving its desired efficiency. Over more than 20 years of operation, the convection coils, primarily consisting of finned tubes, suffered from increased fouling due to inadequate inspection and cleaning practices. The study recommended a potential solution of inspecting and robotically cleaning the external surface of the finned tubes to overcome this issue.
On the advice of the OEM, IGS was contracted to perform Tube Tech’s convection section performance recovery service at a hydrogen production unit at the refinery. The project involved increasing the size of six existing access doors in the convection section and the robotic de-fouling of convection coils.
A performance test run was then conducted to evaluate the unit’s condition after the cleaning process. The unit’s capacity was successfully raised to 100% and maintained for 24 hours. The test procedure for evaluating the unit’s performance after cleaning was based on the HGU’s latest probation test, ensuring consistency and comparability. Data from various sources, laboratory analysis results, outside field/local data and electrical data were collected during the test to accurately assess the unit’s performance.
The successful cleaning of the convection section in the refinery’s HGU marked a significant step toward restoring the unit’s performance. The removal of fouling from the finned tubes facilitated enhanced heat absorption and a reduction in stack temperature, thereby improving overall thermal efficiency. This achievement represents a noteworthy milestone in the refinery’s ongoing expansion project and contributes to its long-term operational success.
Project execution excellence and the ability to rigorously evaluate the future performance of the heater system provides IGS and Tube Tech with an opportunity to offer unique services to clients. This combined approach reflects the increased demand for thoroughly conducted feasibility studies, even for small projects. Moreover, it is essential to quantify the influence, if any, of all IGS products on fired heater performance.
For more information, visit integratedglobal.com or call (888) 506-2669.
