Improving the reliability of the offshore platform power system through the modernization of heat recovery boiler registers

The paper presents the results of the reconstruction of heat recovery boilers UK 11-E-5801 A/B/C/D operated at the offshore ice resistant fixed platform (OIRFP) of the V. Filanovsky field. Systemic operational defects of the equipment manufactured by BBS GmbH were identified. These defects manifested themselves as clogging of flow passages with organic deposits caused by overheating of the 60% aqueous solution of triethylene glycol (TEG) and the subsequent degradation of the heat transfer fluid. Risks of corrosion damage to components due to residual TEG in the pipelines were recorded, as well as threats of metal overheating and complications during hydrostatic testing due to incomplete air removal from the system. To verify the causes of the malfunctions, thermal and gas-dynamic calculations were performed using the ZuluThermo software package. These calculations confirmed that the identified inconsistencies could not be eliminated by adjusting the operating modes and demonstrated the fundamental limitations of the original design, in particular, the lack of the ability to differentially regulate the heat transfer fluid flow across the registers and to ensure complete drainage of the circuit. As part of the modernization, key components were replaced: new custom-made registers KUV-12-150 (PK-142) manufactured by Podolsk Machine-Building Plant JSC were installed; front removable panels, piping, and internal flue gas duct elements were updated, while maintaining the rated capacity of the equipment and making minimal changes to the supporting structure. The implemented series-parallel flow scheme for the heat transfer fluid, combined with the vertical arrangement of coils and a downward TEG flow, ensured uniform heat absorption, reduced hydraulic losses, efficient air removal, and complete drainage of the working medium. The implementation of the technical solutions made it possible to minimize the likelihood of coke formation in the register, stabilize the temperature regime of the coils, and improve the overall operational reliability of the heat recovery boilers.