Low-grade waste energy is widely available in industrial processes, and it typically appears in the form of thermal fluids. Types of technologies are developed for harvesting the thermal energy from these fluids. However, the thermal fluid not only possesses thermal energy, but also contains a large amount of kinetic energy. In this study, a hybrid device is proposed for harvesting both the thermal and kinetic energy of the thermal fluids. A free-standing type triboelectric nanogenerator (TENG) is employed for harvesting the kinetic energy, while a pyroelectric generator (PENG) is used for harvesting the thermal energy. Output performance of discrete water droplets with temperature of 5°C, 25°C, 45°C and 65°C are compared in both the TENG and PENG devices. The effects of the device inclination angle, and droplet released height are discussed. The analyses are conducted based on high-speed video recording of the droplet dynamics on the device as well as numerical simulation. The results indicate the droplet temperature, device inclination angle and droplet released height affect the droplet dynamics significantly. Further, the variation of droplet dynamics greatly affects the output performance of both the TENG and PENG. The peak output power of the TENG decreases with the increase of droplet temperature, while the output power of the PENG increases with the temperature variation. A hybrid energy harvester was fabricated and a peak power density of 2.6 μW/cm² was achieved. A maximum energy increment of 238% was obtained by the hybrid harvester, as compared to the pure PENG device. The harvested energy was able to light up 28 commercial LED light bulbs.

低级废能源在工业过程中广泛可用，并且通常以导热液的形式出现。已经开发出用于从这些流体中收集热能的技术类型。然而，热流体不仅具有热能，而且还包含大量的动能。在这项研究中，提出了一种混合设备，用于收集热流体的热能和动能。独立式摩擦电纳米发电机（TENG）用于收集动能，而热电发电机（PENG）用于收集热能。在TENG和PENG设备中，比较了温度分别为5°C，25°C，45°C和65°C的离散水滴的输出性能。讨论了设备倾斜角度和液滴释放高度的影响。分析是基于设备上液滴动态的高速视频记录以及数值模拟进行的。结果表明，液滴温度，装置倾斜角度和液滴释放高度显着影响液滴动力学。此外，液滴动力学的变化极大地影响了TENG和PENG的输出性能。TENG的峰值输出功率随液滴温度的升高而降低，而PENG的输出功率随温度变化而升高。制造了混合能量采集器，峰值功率密度为2.6μW/ cm 装置的倾斜角度和液滴释放高度会显着影响液滴动力学。此外，液滴动力学的变化极大地影响了TENG和PENG的输出性能。TENG的峰值输出功率随液滴温度的升高而降低，而PENG的输出功率随温度变化而升高。制造了混合能量采集器，峰值功率密度为2.6μW/ cm 装置的倾斜角度和液滴释放高度会显着影响液滴动力学。此外，液滴动力学的变化极大地影响了TENG和PENG的输出性能。TENG的峰值输出功率随液滴温度的升高而降低，而PENG的输出功率随温度变化而升高。制造了混合能量采集器，峰值功率密度为2.6μW/ cm实现了^2个。与纯PENG装置相比，混合收割机获得的最大能量增量为238％。收集到的能量能够点亮28个商用LED灯泡。