Study Of Thermal Shock Mechanical Properties On Ceramic Honeycomb Regenerator

Coal mine gas with low concentration is the clean energy mixed with air during the process of coal mining, many of the coal mine enterprises deal with venting to atmosphere due to its characteristics of low concentration and small amount of output, which will have greenhouse effect on the earth. The thermal reverse flow oxidation technique is a kind of important technical means for the utilization of coal mine gas resource with low concentration. Among them, the honeycomb ceramics are used as an important component of inverse heat oxidation technology core device, thus studying the thermal shock mechanical index,variation of stress can provide a theoretical basis to improve the thermal shock resistance of ceramics and the service life of the oxidation bed.Firstly, this paper studied on the thermal shock and mechanical performance of ceramic regenerative materials by experimental method and numerical simulation method. First of all, this paper studies mechanical performance of ceramic under thermal shock by experimental method. The experiment consists two parts: first,an air cooling method was applied in the thermal shock test(once thermal shock and thermal fatigue experiments) of mullite ceramic specimens;second, the ultrasonic method was used in the physical and mechanical parameter measurement. The experimental results show that: in the process of a thermal shock test, the higher the temperature difference is, the greater the elastic modulus value decrease. In the experiment of thermal shock fatigue for the same cycles, the greater the thermal shock temperature difference is, the smaller the elastic modulus value is; variation of the shear modulus is consistent with variation of the ultrasonic transverse wave velocity; Under thermal shock cycles for many times,the bigger the temperature difference is, the greater Poisson’s ratio fluctuates.Secondly, this paper simulated the variation of both temperature and stress field of honeycomb ceramic regenerator with regular square hole under the condition of actual alternating hot and cold fluid flow. Temperature simulation results show that variation of temperature represents a periodical ascending trend and temperature become stable after a period of time. Stress simulation results show that in the temperature rise process the average temperature of regular square hole in ceramic regenerator vary with time and location and when the temperatureis in periodically stable state the highest thermal stress occurs, the maximum of thermal stress is located near the corner of E line at the entrance of high temperature flue gas.