Heat Exchanger Lifetime

Calculating the critical buckling pressure of a heat exchanger takes time. And when a heat exchanger is already deformed and corroded inside a chemical plant, every second counts. Hargrove constructs some of the most complex industrial plants, ensuring the safety of all involved. When time was of the essence, Hargrove was able to access more processing power, FAST with Ansys.

Challenges

The task of Hargrove Engineers + Constructors was to perform a Fitness-for-Service (FFS) analysis on a client’s process condenser. The condenser, a heat exchanger comprising four different materials and thousands of tubes, experienced corrosion and/or erosion opposite its inlet nozzle. Field ultrasound inspections revealed a thickness below the API- 579/ASME Code minimum allowable.

Technology used

Ansys Mechanical

Engineering solution

FFS-1 general metal loss level 3 FFS analysis confirmed the existing thickness was inadequate and required corrective action. Elastic plastic materials and large deformation theory was used to assess the maximum external pressure before buckling occurs. Following the FFS analysis powered by Ansys Mechanical Enterprise, engineers at Hargrove recommended a novel addition of stiffener rings without cutting the main pressure membrane. As a result, the designed stiffener rings mitigated the buckling risk by elevating the Maximum Allowable External Pressure (MAEP) above Code minimums.

Benefits

• Leveraging the high-performance computing capabilities of Ansys Cloud, Hargrove quickly scaled up their processing power to run simulations faster than ever, significantly reducing the development time and overhead costs.
• The vessel required modification and four stiffening rings were added.
• The product of this analysis provided additional life for the client’s asset, mitigated costs associated with significant repairs and/or total replacement and prevented lost production.