Modeling of Recuperators, Combustion Chambers, Afterburners

Abstract

This category of components includes recuperators, preheaters, regenerators, intercoolers, and aftercoolers, Figure 14.1 Within these components the process of heat exchange occurs between the high and low temperature sides. The working principle of these components is the same ([1, 2, 2]). However, different working media are involved in the heat transfer process. More recently recuperators are applied to small and medium size gas turbine engines to improve their thermal efficiency. The exhaust thermal energy is used to warm up the compressor exit air before it enters the combustion chamber. A typical recuperator consists of a low pressure hot side flow path, a high pressure cold side flow path, and the wall that separates the two flow paths. A variety of design concepts are used to maximize the heat exchange between the hot and the cold side by improving the heat transfer coefficients. A cold side flow path may consist of a number of tubes with turbulators, fin pins, and other features that enhance the heat transfer coefficient. Based on the individual recuperator design concept, hot gas impinges on the tube surface in cross flow or counter flow directions. The working media entering and exiting the recuperator is generally combustion gas that exits the diffuser (hot side) and air that exits the compressor (cold side)