Design and Multiobjective Dynamic Optimization of Superheaters for Load-Following Operation in Pulverized Coal Power...

Area of Science:

• Mechanical Engineering
• Thermodynamics
• Materials Science

Background:

• Pulverized coal power plants require flexible operations for load-following markets.
• Primary superheaters are critical for steam turbine performance but susceptible to failure under high temperatures and pressures.
• Existing designs may not withstand aggressive load-following demands.

Purpose of the Study:

• To optimize the design of future-generation primary superheaters for fast load-following capabilities.
• To develop a robust model for analyzing stress and fatigue damage in superheaters.
• To balance conflicting objectives of minimizing capital and operating costs.

Main Methods:

• Development of a detailed first-principles model for primary superheaters.
• Integration of submodels for stress and fatigue damage analysis.
• Application of single-objective and weighted-metric multiobjective optimization techniques.

Main Results:

• The base case design exhibited potential stress constraint violations during load-following.
• Optimized designs successfully met stress constraints, fatigue life requirements, and steam outlet temperature targets.
• Optimized designs achieved reductions in either metal mass (capital cost) or steam-side pressure drop (operating cost).

Conclusions:

• Optimized primary superheater designs enable flexible and reliable operation in aggressive load-following markets.
• The developed modeling and optimization approach ensures structural integrity and performance.
• This methodology is transferable to other high-temperature heat exchangers across various applications.