Numerical Study of Flow and Heat Transfer of n-Decane with Pyrolysis and Pyrolytic Coking under Supercritical Pressures

作者：Tao, Zhi; Hu, Xizhuo; Zhu, Jianqin^*; Cheng, Zeyuan

来源：Energy & Fuels, 2017, 31(8): 8698-8707.

DOI：10.1021/acs.energyfuels.7b01083

• C-10-C-14 NORMAL-ALKANES
• HYDROCARBON FUEL
• TRANSFER DETERIORATION
• REACTION-MECHANISM
• THERMAL-DECOMPOSITION
• PRODUCT DISTRIBUTIONS
• COOLING CHANNELS
• COKE DEPOSITION
• SURFACE COKING
• MINI-CHANNEL

Pyrolysis and pyrolytic coking of hydrocarbon fuel have significant influences on the regenerative cooling process. In this article, a three-dimensional (3D) model is developed for numerically investigating the flow and heat transfer of pyrolytically reacted n-decane with pyrolytic coking in the engine cooling tube under supercritical pressure. The one-step global pyrolytic reaction mechanism and the kinetic coking model are incorporated into the numerical model to simulate the pyrolysis and pyrolytic coking process of n-decane. The numerical method is validated based on the good agreement between the current predictions and the experimental data. Numerical studies of the characteristics of pyrolysis and surface coking rate at the start time under various outer wall heat fluxes from 1.2 to 1.8 MW/m(2) have been conducted under 5 MPa. Results reveal that heat flux has huge effects on the pyrolytic reaction and the distribution of pyrolytic coking rate. In order to better understand the complicated unsteady physicochemical process, further investigations on coupling relationships between the turbulent flow, heat transfer, pyrolysis and pyrolytic coking in 20 min under a high heat flux of 1.8 MW/m(2) have been performed. It is found that surface coking brings about plenty of negative impacts on the cooling process of n-decane. The mechanisms of these physicochemical phenomena are also analyzed in detail, which would be very helpful in the development of regenerative cooling technology.

• 出版日期2017-8
• 单位北京航空航天大学