Abstract
Power plants are a complicated and expensive asset to acquire and maintain. The corrective and preventive maintenance costs of these power plants are quite significant, hence reducing forced outages due to boiler tube failures is critical in ensuring reliable generation of electricity. Enterprise practitioners seek ideal best practices to reduce escalating maintenance costs and power plant downtime. The cost of corrective maintenance, due to downtime, relative to power generation is significant. The result is a loss of electricity generation capacity and revenue by power plant owners.
World class utilities strive to achieve an international benchmark of less than 1% of unplanned forced outages due to boiler tube failure (BTF), translating to 1 BTF per unit per year (1 BTF/U/Yr.). This research seeks to establish the leading failure mechanisms globally and what global best practices exist in fossil plants. In addition, this research will investigate why BTF persist, despite vast knowledge in this field.
The aim of this study is to research dominant BTF mechanisms in fossil plants in Southern Africa and compare them with international data. To achieve this goal, an electricity generating company in Southern Africa, herein referred to as Company X, is explored. Boiler tube failure incidents from a sample of 13 fossil plants, with a total of 87 generating units for a period from 2016 to 2017 are collected and analysed.
Numerous studies present literature exploring measures towards enhancing the availability and reliability of electricity generating plants. This paper focuses on reducing downtime in electricity generating plants, by identifying leading BTF mechanisms and proactively reducing or eliminating failures associated with leading boiler tube failure mechanisms. The author also considers applicable global best practice measures to enhance the reliability and availability of electricity generating units, by preventing the onset of BTF.
The author focuses on numerous BTF mechanisms in coal-fired power plants. The current research assesses published literature and extracts global best practices that boiler operators employ from high performing utilities. The author analyses and presents research results and global best practices, highlighting correlations between variables (age, capacity and efficiency), BTF and identified dominant failure mechanisms.
The findings from this research depict fly ash erosion as a leading failure mechanism, accounting for 33% of boiler tube failures, this is consistent with global data. This is exacerbated by a high coal ash content (28% ash), due to low-quality coal burnt in the boilers. Reducing the fly ash erosion failure mechanism presents the most prominent opportunity for growth and desirable results...
M.Ing. (Engineering Management)