回热式工质驱动分布式推进系统参数研究

Component Parameters of Recuperated Gas-Driven Distributed Propulsion System

关键词:  航空发动机  分布式推进  工质驱动  换热  热力循环分析

Key words:  Aero-engine  Distributed propulsion  Gas-driven  Heat exchange  Parametric cycle analysis

摘要:

为研究以回热后的压气机引气驱动推进器风扇的工质驱动分布式推进系统（Recuperated Gas-Driven Distributed Propulsion，RGDDP），对其热力循环过程和能量流动展开研究。基于部件法建立了推进系统的设计点计算模型，分析了引气参数和推进器风扇压比对推进系统耗油率的影响，在此基础上，分析了推进系统耗油率对部件效率的敏感性。在不同循环参数下与涡轮电分布式推进系统（Turbo-electric Distributed Propulsion，TeDP）的耗油率进行了对比，得到了RGDDP的热力循环特征。结果表明，引气参数存在最优组合使得推进系统的耗油率最低，同时耗油率对能量传输相关的部件效率敏感性最高；与TeDP相比，涡轮前温度对推进系统的耗油率影响更大，而总压比的影响较小；总涵道比为20时，相对于TeDP，RGDDP具有一定耗油率收益，随着总压比的升高收益降低，总压比为66时仍有3%左右的收益。提高RGDDP总体效率的关键在于降低能量传输过程中的损失并提高换热效率。

Abstract:

In order to research a propulsion system whose propulsor is driven by recuperated bleed from compressor， a design point model was established on basis of the thermodynamic process and energy flow inside the propulsion system. The influence of bleed air parameters and propulsor fan pressure ratio on the specific fuel consumption of the propulsion system was analysed. Then， sensitivity analysis of fuel consumption was carried out on the influence of components efficiency. Fuel consumption of recuperated gas-driven distributed propulsion（RGDDP） was evaluated under various thermal cycle parameters. By comparing the specific fuel consumption of turbo-electric distributed propulsion（TeDP）， the characteristic of RGDDP was clarified. The results show that the parameters of bleed air have an optimal combination to achieve the lowest fuel consumption， which can be obviously impacted by efficiency of components related to energy transmission. Compared with TeDP， the fuel consumption of RGDDP is more sensitive to turbine inlet temperature while overall pressure ratio shows less influence. In the case of a bypass ratio of 20， the fuel consumption of RGDDP is lower than that of TeDP. Though the profit decreases with the increase of overall pressure ratio， there still exists a fuel consumption decrease of 3% when the overall pressure reaches up to 66. The key to improve the total efficiency of RGDDP is bringing down the energy loss during transmission and improving heat exchanger efficiency.