# Effect of Nanofluids on Boiling Heat Transfer Performance
## 6 Conclusions  
Nanofluids are widely used in the future, technology, and military industries. Compared with other applications, nanoparticles have relatively more research and application in heat transfer, and the results are better. However, there are still differences in the effects of the boiling heat transfer performance of nanofluids. This paper analyzes and summarizes the current research literature, and obtains the following conclusions and ideas for the future research of nanofluids in the field of boiling heat transfer. 1. The boiling heat transfer performance of nanofluids is affected by the type, concentration of nanoparticles, base type, and heating surface. Nanoparticle deposition causes the wettability and the number of gasification core points on the heated surface to change, which has an effect on the boiling heat transfer performance. In addition, the nanoparticle deposition surface changes the generation state of the boiling bubble and the escape frequency per unit time. 2. The nanofluid has a strong strengthening effect on the critical heat flux. It is mainly manifested that when the concentration of the nanoparticles is too large and the heating surface roughness begins to decrease, the critical heat flux no longer increases and begins to deteriorate. In addition, the deposition morphology of different nanoparticles increases the capillary force, thereby enhancing the liquid replenishing ability after the bubble is detached. This in turn increases the critical heat flux. 3. The influence of nanofluids on the boiling heat transfer coefficient is still different. The main explanation and analysis is attributed to the formation of a porous deposit on the heated surface of the nanoparticles, which increases the heat transfer resistance of the heated surface and reduces the boiling heat transfer coefficient. In addition, the deposition of nanoparticles on the heated surface causes the critical heat flux to increase faster than superheat, resulting in an increase in the maximum boiling heat transfer coefficient. There is also a large increase in the thermal conductivity of the base liquid to the base liquid, so that the boiling heat transfer coefficient is enhanced. The perturbation of the boiling surface by the nanoparticles increases the thinning of the liquid microlayer on the heated surface, the bubble disturbance is enhanced, and the boiling heat transfer coefficient is enhanced. 4. In view of the divergence of the nanofluids on the boiling heat transfer coefficient, it is found that the dispersion of nanoparticles in the base liquid with higher viscosity has a positive effect on the boiling heat transfer performance because the nanoparticles have a great effect on the thermal conductivity of the base liquid, and the stability is good. Therefore, the deposition of the nanoparticles on the heated surface is small, and thus the enhancement of the thermal conductivity of the base liquid is stronger than the microscopic movement of nanoparticles on the heated surface and the boiling heat transfer performance is enhanced. When the base liquid is a multicomponent solution, the relative movement between the solutions enhances the microscopic motion of the nanoparticles due to the different evaporation order during the boiling process. Therefore, the disturbance of the bubble on the heating surface is enhanced, and the boiling heat transfer performance is enhanced. 5. Compared with the thermal conductivity of the heated surface, the deposition of the low thermal conductivity nanoparticle on the heated surface reduces the heat dissipation rate and improves the wall superheat of the heated surface. Then the enhancement of the boiling heat transfer coefficient of the nanofluid should be attributed to the thermal conductivity of the nanoparticle to the base fluid and the influence of the microscopic motion of the nanoparticle on the disturbance of the heated surface bubble. The movement path in the boiling process can be observed by using a component analyzer by appropriately marking the nanoparticles.