Experimental And Numerical Research On Honeycomb Ceramic Regenerator’s Thermal Characteristics

The honeycomb ceramic regenerators is the most important component of the coal mine ventilation methane oxidation and heat recovery device, its thermal performance directly influence the utilization ratio of coal mine ventilation methane. So studying the thermal characteristics of honeycomb ceramic regenerator has great significance in making full use of coal mine ventilation methane, saving energy, improving the environment. This paper has systematically studies on the thermal characteristics of honeycomb ceramic by using experimental test and numerical simulation, which provides data support for the optimum design of coal mine ventilation methane oxidation device and the research development of heat recovery equipment.In this paper, the effective thermal conductivity of honeycomb ceramic regenerator has been carried on the experimental measurement, obtained that effective thermal conductivity is greater than the absolute thermal conductivity. The higher the temperature, the greater the radiation effect on the effective thermal conductivity. Temperature has greater influence on the effective thermal conductivity of the honeycomb ceramic than porosity. High porosity and mullite honeycomb ceramic has the larger effective thermal conductivity at high temperature.The constant-pressure specific heat coefficient of honeycomb ceramics has been tested with experimental measurement, concluded that the changing trend of same material honeycomb ceramic constant-pressure specific heat coefficient with temperature is almost the same. The change of honeycomb ceramic constant-pressure coefficient is small at low temperature, but it is larger at high temperature. The constant-pressure specific heat coefficient of mullite honeycomb ceramic is bigger at the same temperature.The resistance characteristics and heat release characteristics changing rules of honeycomb ceramic is studied through experiment method with the honeycomb ceramic structure parameters and operating parameters. It is concluded that the resistance loss of four square pore, small porosity honeycomb ceramic regenerator is the largest at larger cold air flow and higher experimental temperature. The resistance loss in temperature rising period is greater than that in temperature falling period under the same operating condition. Six square pore, small porosity, mullite honeycomb ceramic has the bigger heat transfer coefficient, faster heat release rate, and higher heat transfer ability with cold air at the larger cold air flow and higher experimental temperature.The pressure drag loss and the velocity distribution of the honeycomb ceramic under steady state conditions caused by the hot air in and out is numerically calculated by using computational fluid dynamics software Fluent with establishing the single channel model. It is concluded that the law of the numerical calculation and the experimental measurement is consistent, the pressure resistance loss obtained by experimental measurement is larger than that obtained by numerical simulation, it is mainly caused by the local resistance loss. But the local resistance loss accounts for the percentage of the total resistance loss is not big, we can consider that numerical simulation established single channel model and various physical property parameter setting is reasonable.