A Comprehensive Investigation of the Pyrolysis Effect on Heat Transfer Characteristics for n-Decane in the Horizon Mini-Channel

Abstract

In order to better understand the heat transfer process with the pyrolysis of hydrocarbon fuel, the pyrolysis effect on heat transfer characteristics in the mini-channel was comprehensively investigated in this work. First, the heat transfer characteristics were experimentally measured, and the thermophysical properties of fuel were calculated according to the species distribution. Then, the heat transfer and thermophysical properties in an ideal condition (no pyrolysis in the same heat flux) were simulated by a numerical method. By comparing the experimental results with the simulation results, it could be found that pyrolysis can significantly inhibit the rising of fuel temperature up to 332 K. Meanwhile, pyrolysis can significantly decrease the density, increase the viscosity and thermal conductivity, and keep the specific heat capacity approximately at a constant. Then, the variation of thermal properties can decrease the Reynold number and Prandtl number, thus impairing the heat transfer performance. However, while pyrolysis occurs from a mild degree to a deep degree, the heat transfer will be enhanced. This phenomenon may be caused by the dramatic difference of pyrolysis in the radial direction. At the same time, in the high-temperature region, the percentages of the chemical heat sink in the total heat sink are all over 50%. Especially in these low mass flux conditions, the percentages of chemical heat sink can be up to 65%. According to the results of this work, both the negative and positive effect of pyrolysis should be taken into consideration in cooling structure design.

Comparison and Evaluation of Transport Property Prediction Performance of Supercritical Hydrocarbon Aviation Fuels and Their Pyrolyzed Products via Endothermic Reactions

“…The transport properties of pure hydrocarbons and mixtures were predicted and compared in the ranges of temperatures between 300 and 1000 K and pressures between 0.1 and 5.0 MPa [35,44]. The range includes most hydrocarbons' critical points, as presented in Section 3.2, as well as the most states considered in several thermal cracking studies [12][13][14]48].…”

Research status of supercritical aviation kerosene and a convection heat transfer considering thermal pyrolysis

“…It is vital to obtain accurate properties of aviation kerosene for computational calculation. According to the existing literature, SUPERTRAPP, Aspen HYSYS, Aspen Plus and REFPROP, developed by the National Institute of Standards and Technology (NIST) (NIST, 1999), are always used to achieve the properties of aviation kerosene (Yang et al , 2020; Li et al , 2018; Bao et al , 2012; Jiao et al , 2020). The properties are also obtained by in-house codes based on extended corresponding state principles, which are always incorporated into the commercial softwares (Ruan et al , 2014; Tao et al , 2019; Wang et al , 2010).…”

Effect of Cooling Header on the Hydrocarbon Fuel Flow Distribution in a Regenerative Cooling Channel

“…In particular, fluid density [4], viscosity, specific heat, and the thermal diffusion coefficient change dramatically [5,6] near the quasicritical point. The buoyancy and flow acceleration caused by the change in physical parameters have a massive effect on the heat transfer of the fluid [7][8][9]. Under high temperatures, coking and carbon deposition caused by the pyrolysis of hydrocarbon fuel can also cause the blockage of regenerative cooling channels [10][11][12][13][14][15].…”