Modeling and performance evaluation of a new multi-physical coupled system of photovoltaic-thermoelectric-interfacial evaporation

Interfacial evaporation, as an emerging seawater desalination technology, combines it with photovoltaic power generation technology and utilizes photovoltaic waste heat to drive interfacial evaporation, which is an effective measure for solving the problem of water and electricity shortage in off-grid island areas. Accurate calculations for different coupled forms of solar energy utilization systems are necessary to reduce the cost of preliminary experiments. In this paper, a coupled photo-electric-thermal-interfacial evaporation model is established based on photoelectric conversion model, heat transfer model, thermoelectric conversion model, and interfacial evaporation model, which is used to calculate the effects of meteorological parameters such as solar irradiance, ambient temperature, and ambient wind speed on the output performance of photovoltaic-interfacial evaporation and photovoltaic-thermoelectric-interfacial evaporation coupled systems, and experimental studies are carried out to validate the reliability of the model. The results show that the model has an average simulation error of 3.97 % for Photovoltaic module output power, 2.29 % for photovoltaic surface temperature, 6.11 % for thermoelectric generator output power, and 8.77 % for evaporation. Under the same conditions, the coupled photovoltaic-interfacial evaporation system has a lower net solar power generation efficiency than the coupled photovoltaic-thermoelectric-interfacial evaporation system but has a higher solar energy utilization and interfacial evaporation rate. As the emissivity of the photovoltaic surface increases, the net solar power generation efficiency of the system rises, but the interfacial evaporation rate and the utilization rate of solar energy of the system decrease. With the increase of output voltage of photovoltaic module, the net solar power generation efficiency and solar energy utilization rate of the system exhibit a trend of first increasing and then decreasing, while the interface evaporation rate of the system shows the change trend of first decreasing and then increasing.