低温冷能驱动的高效行波热声发电系统研究

Cryogenic liquids, such as liquid natural gas and hydrogen, contain a great quantity of low temperature cold energy. Thermoacoustic power generation system provides a new way for utilizing cryogenic energy for its merits, such as high efficiency, simple configuration, and stable operation. The applicant is intended to investigate efficient travelling-wave thermoacoustic power generation system driven by cryogenic energy. In theoretical research, the working mechanism of traveling-wave thermoacoustic engines driven by cryogenic energy will be revealed from the two aspects of thermodynamic cycle of heat engine and microscopic working process. The factors that influence the performance of thermoacoustic conversion will be quantitatively determined. And then an effective way to improve the conversion efficiency from cryogenic energy to power will be found. The effective method to modulate the acoustic field of the travelling-wave thermoacoustic engine will be explored, and then be applied to optimize the matching between the high power thermoacoustic engine and transducers. Based on dynamics analysis, the working characteristics of the crank connecting rod transducer which can be used in thermoacoustic power generation will be studied, and the working stability criterion of the transducer which is matched with thermoacoustic engines will be built. The alternating flow and heat transfer processes in the low temperature heat exchanger of the regenerator will be studied and novel structures of compact phase change heat exchanger will be proposed. In experimental study, a high power travelling-wave thermoacoustic power generation system driven by cryogenic energy will be built. By optimizing the structure and operation parameters of the thermoacoustic power generation system, the onset temperature difference of the thermoacoustic engine is made no more than 100 K, the power generation system can output 5 kW electric power, and thermal-to-electric efficiency is higher than 20%. This research will Lay the theoretical and experimental foundation for thermoacoustic technology applying in cryogenic energy utilization.

液化天然气、液氢等低温流体中蕴含着巨量的低温冷能，热声发电因效率高、结构简单和运行可靠等独特优点为低温冷能利用提供了新思路。申请人拟开展低温冷能驱动的行波热声发电系统研究。在理论方面，从热机工作循环和微观工作过程两个层面深入揭示低温冷能驱动型行波热声发动机的工作机理，定量确定低温冷能驱动型热声转化效应的影响因素，找到提高热功转化效率的有效途径；探索调制行波热声发动机声场的有效方法，优化发动机和换能器的匹配。基于动力学分析方法研究可用于热声发电的曲柄连杆式换能器的工作特性，建立与热声发动机匹配的曲柄连杆式换能器的稳定性判据；深入探究大功率低温热声换热器中的交变流动与传热过程，提出新型的紧凑式热声低温相变换热器结构。在实验方面，搭建低温冷能驱动的行波热声发电系统，使发动机的起振温差低于100 K，实现5 kW的电功输出，热效率高于20 %。从而为热声技术应用于低温冷能利用奠定理论和实验基础。

液化天然气、液氢等低温流体中蕴含着巨量的低温冷能，热声发电因效率高、结构简单和运行可靠等独特优点为低温冷能利用提供了新思路。本项目开展了低温冷能驱动的行波热声发电系统研究。在理论方面，从热机工作循环和微观工作过程两个层面深入揭示了低温冷能驱动型行波热声发动机的工作机理，定量确定了低温冷能驱动型热声转化效应的影响因素；深入探索了调制行波热声发动机声场的有效方法，优化了发动机和换能器的匹配。基于热力学和动力学分析方法研究了可用于热声发电的曲柄连杆式换能器的工作特性，建立了与热声发动机匹配的曲柄连杆式换能器的稳定性判据；研究了大功率低温热声换热器中的交变流动与传热过程，研制出新型的紧凑式热声低温相变换热器结构。在实验方面，搭建了低温冷能驱动的行波热声发电系统并开展了实验研究，验证了低温下热声系统起振温差更小，低温冷能驱动的热声发动机达到1.75bar的压力振幅，系统性能优于相同温差条件下的热驱动型热声系统。本课题研究为热声技术应用于低温冷能利用奠定了良好的理论和实践基础。