Experimental study of a thin water-film evaporative cooling system to enhance the energy conversion efficiency of a thermoelectric device

• Published in: Energy (Oxford) 2020-11, Vol.211, p.119040, Article 119040
• Main Authors: Zheng, Liang Jun, Lim, Sungmook, Kim, Na Kyong, Kang, Dong Hee, Youn, Young Jik, Lee, Wonoh, Kang, Hyun Wook
• Format: Article
• Language: English
• Subjects: Electricity/steam generation; Evaporative cooling; Experimental investigation; Thermoelectric generator (TEG); Thin water film
• ISSN: 0360-5442
• DOI: 10.1016/j.energy.2020.119040

In the study, a new method to enhance the performance of a thermoelectric generator (TEG) device by utilizing the water-film evaporative cooling is proposed. An experimental device was constructed by incorporating a water-film cooling pond with a commercially available TEG. Experiments were performed to investigate the effects of the main operating conditions (ambient temperature Tamb was 25 °C), TEG hot-side temperature (TH = 50–100 °C), ambient relative humidity (RH = 15–90%), and water-film thickness (twater = 1–9 mm) on the TEG output performance. Additionally, the output performance of TEG under different cooling methods was compared. A TEG prototype device was constructed to generate electricity/steam using seawater evaporation cooling without external electrical energy. The results indicated that TEG hot-side temperature and water-film thickness significantly affected output performance. However, the ambient relative humidity did not considerably affect TEG output performance. Given TEG hot-side temperature TH = 100 °C, ambient relative humidity RH = 15%, the TEG prototype device-generated open-circuit voltage of Uopen = 1.55 V, maximum output power of Pmax = 290.32 mW, and a steam generation rate of 9.82 mg/s. The results showed that evaporative cooling is an innovative method to improve the performance of TEG. [Display omitted] •Eco-friendly evaporative cooling method to improve the thermoelectric performance.•Thin water evaporation has a higher cooling capacity than traditional heat sink.•Ambient relative humidity is independent factor to the thermoelectric performance.•Thin film evaporator applied to freshwater production and waste heat recovery.