超临界CO2半布雷顿冷电联供系统特性研究OA

To address the challenges of thermal protection and power supply insufficiency faced by hypersonic vehicles,a supercritical CO2 semi-Brayton cooling and power system is proposed.In this system,the CO2 on the high-pressure side absorbs the aerodynamic heat in a transcritical manner during the cooling process of the vehicle's wall,expands to perform work,and then is discharged into the environment.This configuration simultaneously cools the high-temperature wall and generates electrical energy,achieving both cooling and power.Considering the typical operating conditions of hypersonic vehicles,a thermodynamic analysis of the system is conducted,and the effects of varying heat absorption pressures and outlet temperatures within the cooling channel on the system's cooling and power generation capabilities are studied.The results indicate that compared with a closed Brayton system,the proposed system significantly enhances the combined cooling and power performance.Specifically,under different heat absorption pressures,the amount of absorbed aerodynamic heat increases by 9.1%-31.3%,and the output power increases by 19.0%-42.8%.Moreover,with varying outlet temperatures in the cooling channel,the heat absorption increases by 13.2%,and the output power increases by 38.0%.Notably,when the heat absorption pressure is between 10 MPa and 30 MPa and the cooling channel outlet temperature is between 770 K and 1 000 K,the system achieves a remarkable thermal efficiency of up to 40.8%.Furthermore,when operating for less than 60 minutes,the mass of the semi-Brayton system is lower than that of a closed Brayton system,demonstrating a 54%reduction in the mass compared with the battery.Collectively,the supercritical CO2 semi-Brayton cooling and power system presented in this study offers a novel solution for the new demands of harsh thermal protection and power supply faced by future hypersonic vehicles.