Heat transfer enhancement in pool boiling and condensation using h-BN/DCM and SiO₂/DCM nanofluids: experimental and numerical comparison

Abstract

Purpose The purpose of this study is to experimentally and numerically scrutinize the heat transfer enhancement in pool boiling and condensation by changing the hydrophilicity or hydrophobicity properties of the working fluid, i.e. by use of nanofluid solution. Design/methodology/approach For specifying the effects of nanoparticle concentration on heat transfer properties, two different nanofluid solutions (h-BN/DCM and SiO2/DCM) at three different volumetric concentrations were prepared and tested under different heat flux conditions. Boiling curves, alterations in pressure with heat flux and heat transfer coefficients for both boiling and condensation processes were obtained and viscosity measurements were performed for dichloromethane (DCM) and each working fluid was prepared. In addition, a series of numerical simulations, via computational fluid dynamics approach, was performed for specifying the evaporation–condensation phenomena and temperature and velocity distributions. Findings Nanoparticle addition inside the base fluid increased the thermal characteristics of the base fluid significantly. For the experimental results of h-BN/DCM nanofluid, the increment rate in heat transfer coefficient for saturation boiling, after-saturation boiling and condensation processes was found as 27.59%, 14.44% and 15%, respectively. Originality/value The novelty of this comparison study is that there is no such experimental and numerical comparison study in literature for DCM fluid, which concentrates on thermal performance enhancement and compares the effect of different kinds of nanoparticles on heat transfer characteristics for boiling–condensation processes.

Effect of Nanofluids on the Enhancement of Boiling Heat Transfer: A Review

“…Under cleaner conditions, these nanoparticles can also be produced and their surface can be saved from sudden coatings that can occur during the gas condensation phase [8,9]. The simple procedure of nanofluids preparation is shown in figure 4, Where nanoparticles are fixed up with base fluids in order to get the nanofluids [10]. Two key methods of preparing nanofluids are available.…”

“…Ciftci et al [10] experimentally and numerically scrutinized the heat transfer enhancement in pool boiling and condensation by changing the hydrophilicity or hydrophobicity properties of the working fluid, i.e. by using nanofluid solution.…”

“…Figure 8: Boiling curves for DCM, h-BN/DCM and SiO2/DCM nanofluids under (a) saturation (b) after saturation conditions at various concentration[10] …”

Su Esaslı Seyreltik Fe+ZnO Hibrit Nanoakışkanının Düşük Isı Akısı Şartında Havuz Kaynama Isı Transferi Özellikleri: Sayısal Bir Çalışma

“…Numerical analysis is widely preferred, especially in the validation of the results obtained by experimental studies, and can be performed on almost all heat transfer and fluid flow problems via factual assumptions [11,12]. In order to reduce the number of tests required in the solution of such problems, a range of analyses can be carried out.…”

“…In this study, the equations of conservation of mass, conservation of energy, governing equation for diffusion in VOF(Volume-of-Fluid) multiphase flow model, and RNG k-ε turbulent model were solved. The theoretical background for these equations can be found in the references [11] and [12].…”