A review of recent advancements in micro combustion techniques to enhance flame stability and fuel residence time

Abstract

The need for Power Micro Electro Mechanical Systems (Power MEMS) is growing as microfabrication techniques and microelectronics advance. Conventional chemical batteries have insufficient energy density to use Power MEMS. Hydrogen and hydrocarbon fuel combustion provides a more attractive alternative to traditional batteries. The micro burner has a small combustion chamber, surface area to volume ratio increases, which causes heat losses and instability. Therefore, fuel burns inefficiently, and the flame is unstable because of the short residence time of the premixed fuel/air. Flame instability, short residence time, and poor combustion efficiency are the main issues affecting micro combustion. Therefore, enhancing the fuel's residence time and flame stabilization in micro combustions is essential. To achieve better combustion, the current review articles mainly discuss micro combustion techniques, which have progressed in recent and last decades. Introducing a porous medium could enhance micro combustor performance. Catalytic combustion and integration of porous medium into MTES and MTPVS are recommended. Catalytic combustion aims to accelerate the reaction rate, prolong the time fuels spend in the combustion chamber, and maintain a constant flame. It was suggested that hydrogen be added to the combined gas. It would be ideal if the combined gas's equivalence ratio φ is between 0.9 and 1.1 for better performance. Its recommended bluff body blockage ratio ζ set between 0.4 and 0.5 enhances combustion stability and fuel residence time. This article overviews the micro combustion characteristics, micro combustion techniques, and their mechanism. At the end of this article, we also discussed the best strategies to overcome the issues of micro combustion for designing a new efficient micro combustor in the future.