Experimental study on heat transfer performance of nanofluid cooling under high heat flux density

High power devices such as fast-charging equipment for new energy vehicles and laser technologies may experience efficiency degradation or even damage due to overheating during operation, making high heat flux cooling technologies a research focus. To address the limited heat-carrying capacity of traditional cooling media, the cooling performance of TiO2 nanofluids under high heat flux conditions was investigated, and a heat transfer experimental test platform under high heat flux density of spray cooling was established. The effects of TiO2 mass fraction, spray flow rate, and heating power on cooling performance are examined. The results demonstrate that the 0.1 wt.% TiO2 nanofluid achieves the optimal performance, with a heat transfer coefficient of 3.59 W/cm?K. Higher mass fractions lead to increased viscosity and particle interactions, reducing heat transfer efficiency. Furthermore, increasing the spray flow rate enhances cooling performance, but higher TiO2 concentrations lead to reduced performance due to particle deposition on the heat source surface. The TiO2 nanofluids exhibit significant advantages under high heat flux density. Surface temperature of 25.3?C, at a heating power of 500 W, can be maintained with 0.1 wt.% TiO2 nanofluid. This research provides valuable insights for optimizing the use of TiO2 nanofluids in high heat flux density applications.