Numerical investigation of pyrolysis and surface coking of hydrocarbon fuel in the regenerative cooling channel. (1st December 2022)

• Record Type: Journal Article
• Authors: Tian, Ke; Tang, Zicheng; Wang, Jin; Ma, Ting; Zeng, Min; Wang, Qiuwang
• Is Part Of: Energy. Volume 260(2022)
• Publication Date: 2022-12-01
• Subjects: Pyrolysis -- Surface coking -- Heat transfer -- Supercritical pressure -- Hydrocarbon fuel -- Regenerative cooling; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Energy consumption -- Periodicals; 333.7905
• DOI: 10.1016/j.energy.2022.125160
• Languages: English
• ISSNs: 0360-5442

Abstract

Abstract: Fuel pyrolysis is a common phenomenon in regenerative cooling channels. However, the alkenes and aromatic hydrocarbons produced by thermal cracking tend to deposit on the channel surface, leading to local heat transfer deterioration, corrosion resistance reduction, or blockage. This study establishes a numerical investigation at a supercritical pressure to evaluate the fuel flow effects on thermal cracking and surface coking. The results indicate a threshold of fuel flow rate or conversion rate that can improve the utilization of chemical heat sink. The threshold of the conversion rate for RP-3 fuel (Rocket Propellant No. 3 jet fuel) is around 80%, exceeding which will reduce the benefits of fuel endothermic pyrolysis. Moreover, a critical criterion of buoyancy parameter has been proposed for the severe pyrolysis of RP-3 fuel. In addition, the variation of fuel flow significantly influences the distribution of wall temperature and coking precursors, which further affects the coke layer thickness. Highlights: A modified parameter is developed to evaluate the utilization of chemical heat sink. The threshold of the conversion rate for Rocket Propellant No. 3 jet fuel is around 80%. A threshold of buoyancy parameter is proposed for severe pyrolysis. More cokes will deposit on the surface with decreasing mass flow rate.