连续燃烧分缸工作型发动机理论热力循环分析  

Theoretical Thermodynamic Cycle Analysis of Continuous Combustion Multi-Cylinder Engine

作　　者：吴晗[1] 张泽宇 孙柏刚[1] 李向荣[1] WU Han;ZHANG Zeyu;SUN Baigang;LI Xiangrong(School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学机械与车辆学院,北京100081

出　　处：《兵工学报》2023年第1期74-83,共10页Acta Armamentarii

摘　　要：连续燃烧分缸工作型发动机因其热效率及功率密度高,振动及噪声小,未来将在小型无人机及鱼雷上具有很好的应用前景。该型发动机将压缩、燃烧和膨胀过程分缸进行,同时使用进气掺水、不等缸径、回热器和连续外燃技术,被认为具有极高的热功转换潜力,但目前缺乏对其热力循环的研究,导致在发动机设计过程中缺乏理论指导。将发动机各工作阶段等效为定温压缩、定容加热、定熵膨胀、排气放热与回热共5个工作过程,构建出新型理论热力循环并推导出指示热效率公式。研究结果表明:指示热效率主要由工质热物性、压缩比、膨胀比和回热率决定,增大压缩比或降低膨胀比均可提升指示热效率;应用定温压缩后可扩大回热温差,提升指示热效率,同时还可保持较低的缸内温度和压力;该型发动机热效率及可靠性较传统汽油机、柴油机具有显著优势,发动机指示热效率可达65%以上。The continuous combustion multi-cylinder engine has promising application prospects in mini unmanned aerial vehicles and torpedoes because of its high thermal efficiency and power density, and low vibration and noise. The engine works with separate cylinders for the compression, combustion and expansion processes. The technologies of water induction, unequal bore size, recuperator and continuous external combustion are also adopted. It is considered to have high potential in heat-work conversion. However, the lack of research on its thermodynamic cycle means the lack of theoretical guidance for the design of the engine. The engine working stages can be equivalent to 5 processes: isothermal compression, constant volume combustion, isentropic expansion, exhaust heat release and recuperation. A new theoretical thermodynamic cycle is constructed and the equation of its indicated thermal efficiency is derived. It is found that: the indicated thermal efficiency is mainly determined by the working medium’s thermo-physical property, compression ratio, expansion ratio and recuperation ratio;with the increase of compression ratio and the reduction of expansion ratio, the indicated thermal efficiency is improved;especially, isothermal compression can enlarge the recuperative temperature difference which leads to a significant increase of indicated thermal efficiency;meanwhile, the temperature and pressure in the cylinder is not increased;this engine is proved to have higher thermal efficiency and operation reliability than traditional gasoline and diesel engines;the calculation results show that the indicated thermal efficiency of the engine can reach more than 65%.

关 键 词：连续燃烧分缸工作型发动机 理论热力循环 指示热效率 定温压缩 

分 类 号：TK123[动力工程及工程热物理—工程热物理]