Evaluation the Scramjet Cooling Heat for Available Work Using Exergy Analysis

Abstract

The scramjet cooling heat has a big potential work between the heat and the fuel coolant. However, there is no idea about the maximum potential work of the heat from cooling scramjet. Therefore, the potential work of the scramjet cooling heat is studied. The maximum available work from the heat of cooling scramjet is evaluated by the exergy analysis. The heat exergy analysis model is proposed under the heat sources condition according to the heat transfer performance of the scramjet wall and fuel coolant. It is supposed that a closed thermodynamic system is performed between hot source and cold source. The heat flow, the heat exergy and the available work from the scramjet wall are 543.1kW, 407.3kW and 370.3kW, respectively, when the temperature of scramjet wall is 1200K. And the exergy efficiency of the closed system is 68.2%. The exergy losses of external irreversible processes between the closed system and heat sources are analyzed by considering the heat exchanging temperature differences. The external exergy losses and the exergy efficiency have been largely changed with the heat exchanging temperature differences between the closed system and heat sources. The heat exchanging temperature differences are decreased, the external exergy losses are decreased and the exergy efficiency is increased. However, the heat exchanging temperature differences would be adapted to heat exchanging processes and decreasing the acreage of heat exchange. It is meaningful for having a guidance of power generation for hypersonic vehicle.