双作用自由活塞型斯特林发电系统性能研究

Study on Performance of Double Acting Free Piston Stirling Power Generation System

自由活塞斯特林发动机作为一种高效的能源转换装置,在可再生能源利用等领域有重要的应用前景。本文针对一种双作用自由活塞型斯特林发电系统,从声电耦合原理出发,推导了双作用斯特林发动机与直线电机之间的阻抗匹配方程,建立了发电系统的整机数值模型,并获得了加热温度、平均压力、活塞连杆直径、机械阻尼和间隙密封宽度等参数对整机性能的影响规律。结果表明,由于双作用活塞两侧同时存在较大的温差和压差,因此相较于单作用结构的系统而言,活塞间隙大小对该系统性能影响更大,这是导致效率变化的关键因素之一。经过优化计算,设计了一台四单元双作用自由活塞斯特林发电机,在加热温度600?C、放热温度20?C和平均压力8 MPa的额定工况下,每个发电单元可输出1.41 k W的电功,热电效率为40.8%,为后续实验研究奠定相关的理论基础。

As an efficient energy conversion device,free piston Stirling engine has important application prospects in renewable energy utilization and other fields.Aiming at a double acting free piston Stirling power generation system,starting from the principle of acoustic electric coupling,this paper deduces the impedance matching equation between double acting Stirling engine and linear motor,establishes the numerical model of the whole power generation system,and obtains the infuence laws of parameters such as heat source temperature,average pressure,piston connecting rod diameter,mechanical damping and gap seal width on the performance of the whole machine.The results show that due to the large temperature difference and pressure difference on both sides of the double acting piston,the influence of the piston clearance on the system performance is greater than that of the single acting structure,which is one of the key factors affecting the system efficiency.After optimization calculation,a four unit double acting free piston Stirling generator is designed.Under the rated working conditions of hot end temperature of 600°C,cold end temperature of 20°C and average pressure of 8 MPa,each power generation unit can output 1.41 kW,and the thermoelectric efficiency is 40.8%,which lays a relevant theoretical foundation for subsequent experimental research.