In the quest to make coal-fired power plants more adaptable to the fluctuating demands of modern power grids, researchers have turned to an innovative approach: thermal storage-assisted load reduction. A recent study, published in the journal *Fuel Processing Technology*, explores how this method can enhance the performance of circulating fluidized bed (CFB) boilers, a critical component in many coal-fired power systems.
Led by Zengcai Ji of the School of Renewable Energy at Inner Mongolia University of Technology and the Inner Mongolia Key Laboratory of New Energy and Energy Storage Technology, the research delves into the combustion and emission characteristics of CFB boilers during load reduction. The findings suggest that integrating thermal storage into these systems could significantly improve their flexibility and efficiency.
CFB boilers are known for their ability to handle a variety of fuels and their relatively low emissions. However, they also have a notable drawback: significant thermal inertia, which limits their ability to quickly adjust to changes in power demand. This is where thermal storage comes into play. By storing heat during periods of low demand and releasing it when demand spikes, the system can respond more swiftly to grid fluctuations.
The study found that thermal storage-assisted load reduction can indeed enhance the boiler’s load regulation performance, but the effectiveness varies depending on the load range. “When reducing from 100% to 50%, the load reduction rate increased by 23%,” Ji explained. “However, when reducing from 50% to 30%, the rate decreased by 62%.” This variability underscores the complexity of optimizing thermal storage systems for different operational scenarios.
The research also revealed that thermal storage-assisted operation slightly improves combustion efficiency and reduces CO emissions, but it increases NOx emissions. This trade-off highlights the need for further refinement of the technology to minimize environmental impacts.
One of the most intriguing findings was the effect of increasing the amount of stored heat. Larger amounts of stored heat led to significant changes in the furnace temperature distribution, with larger temperature drops in the lower region and smaller drops in the upper region. This redistribution of heat not only improved the load reduction rate but also enhanced combustion efficiency and reduced CO emissions. “Increasing the stored material to 34% led to a remarkable 111% improvement in the load reduction rate when reducing from 100% to 50%,” Ji noted.
The implications of this research for the energy sector are substantial. As power grids increasingly rely on renewable energy sources, the need for flexible and responsive power plants becomes ever more critical. Thermal storage-assisted load reduction could be a key technology in meeting this challenge, enabling coal-fired power plants to operate more efficiently and adaptably.
Moreover, the findings could pave the way for further innovations in thermal storage technologies, potentially extending their application to other types of power plants and industrial processes. As the energy sector continues to evolve, such advancements will be crucial in ensuring a stable and sustainable power supply.
In the words of Zengcai Ji, “This research opens up new possibilities for improving the performance of CFB boilers and contributing to the stability of modern power grids.” As the energy landscape continues to shift, the insights gained from this study could play a pivotal role in shaping the future of power generation.