An overview of the development and potential of ceramic materials for use in micro gas turbines

Abstract: This paper presents an analysis of the potential of Micro Gas Turbines (MGT) with regards to performance, economic and durability considerations. The performance potential was assessed by calculating the cycle efficiency based on the Brayton cycle and the mechanical efficiency of the expansion turbine. The economic potential was evaluated by calculating the specific fuel consumption and estimating the cost and manufacturability of the turbine components. The durability and reliability of the components were assessed by considering the effects of transient thermal stresses and unstable ignition. The results indicated that ceramic materials can achieve a 63% increase in efficiency over nickel-based alloys and a 39% reduction in specific fuel consumption. It was also found that the grinding process on the metal-ceramic shaft connection is the most expensive as it relies on diamond grinding, while ceramic turbines can have an initial procurement cost advantage whenproduced in higher volumes. Finally, it was found that ceramic materials are less reliable due to their higher hardness and sensitivity to pressure spikes, and therefore require careful consideration when designing the components.