Zhenqiang Gao

Numerical Simulation on Resistance of the Combined Regenerative Oxidation Bed

Thermal reverse flow reactor is effective for the oxidation of coal mine ventilation air methane. The resistance of the regenerative oxidation bed in this device is numerically investigated using porous medium model by fluent software in this paper. The pressure loss in the square honeycomb ceramic oxidation bed is larger than that in hexagonal honeycomb ceramic oxidation bed, but the outlet temperature is lower. Then a combined oxidation bed which consisted of square and hexagonal honeycomb ceramic is proposed, in which the hexagonal honeycomb ceramic is filled in the central of the combined bed, and the square honeycomb ceramic is filled in the two sides. The resistance loss and outlet temperature for seven kinds of combined beds are calculated. The results indicate that the suitable length of hexagonal ceramics in the combined oxidation bed is ranged from 1m to 1.4m.

Study of Key Parameters of Thermal Flow Reversal Reaction

Thermal flow reversal reaction (TFRR) is a proper method to deal with lean methane. Heat recovery efficiency, peak temperature and switching time are key parameters of TFRR. Experiments were carried out to study these parameters. The results show that: the quality of heat energy loses in the process of heat transfer; the peak temperature could be controlled by changing of switching time; withdraw hot gas from the end of reactor is not proper for energy output.

Simulation of Outlet Hot Gas Withdrawal from a Reverse Flow Reactor for Thermal Oxidation of Lean Methane

Results of simulation concerning a reverse flow reactor for thermal oxidation of lean methane are presented. The method termed outlet heat gas withdrawal is employed and analyzed. The method is direct withdrawal of heat from the outlet of the reactor. Simulations show that a relation exists between the outlet temperature of hot gas withdrawal and the methane concentration. The results reveal that outlet hot gas withdrawal guarantees symmetry of the semi-cycle temperature profiles of reverse flow and the cyclic steady state operation of the reactor can be easily obtained.

Modeling a Reverse Flow Reactor for Thermal Oxidation of Lean Methane

A full dynamic one-dimensional model of a reverse flow reactor for thermal oxidation of lean methane and a code for its solution are employed. The simulation concerning starting up of the reverse flow reactor is carried out. An electric heater at the end of the reactor is employed during starting up of the reactor. The influence of heating operation of the heater and the hot region moving from the end to central part during starting up of the reactor has been investigated in detail. The results show that the initial temperature profiles on the central part of the reactor can be obtained in two steps.