Experimental Study On Heat Transfer And Resistance Characteristics Of Honeycomb Regenerators

Honeycomb regenerators have been widely used in industrial furnaces for its good energy recycling efficiency. Its heat transfer performance and resistance performance will directly affect the energy use efficiency. Therefore, the study of the internal heat transfer characteristics and resistance characteristics of honeycomb regenerators have great meaning for improving the furnaces’ energy saving. The thesis presents an intensive investigation on heat transfer characteristics and resistance characteristics in honeycomb regenerators experimentally. Based on the single-blow methodology, an experimental setup is designed to measure the convective heat transfer coefficients and resistance coefficients in honeycomb regenerators. The research results will give suggestion of selecting the type of honeycomb regenerator and the operating mode.Part one, the characteristics of convective heat transfer are studied experimentally. The effects of fluid characteristic and honeycomb regenerator’s geometrical properties (such as hydraulic diameter, porosity and hole pattern) on heat transfer are investigated in detail. Through the theoretical analysis of internal heat transfer process, write a computer program used to get the average heat transfer coefficient from measured temperature data. Experimental results show that the gas temperature change rate and solid temperature change rate in honeycomb monoliths first increase then decrease from entrance to exit. The study also finds that the average convective heat transfer coefficient increases with the time flow, but when the flow velocity becomes larger, its growth rate fell. The average heat transfer coefficient increase with the hydraulic diameter decrease. When the porosity becomes smaller, the average heat transfer coefficient change rate increases. The hole pattern also has an influence on heat transfer rate. The best pattern for heat transfer is circular. The material properties of monoliths have little effect on heat transfer. Based on the experimental data, the convective heat transfer experimental correlation is obtained. Part two. the characteristics of fluid flow in the honeycomb regenerators are studied experimentally. The effects of air flow, air temperature and honeycomb regenerator’s geometrical properties on the resistance are investigated. The research results show that with the air flow increasing, or the hydraulic diameter and porosity decreasing, the regenerator resistance increase. And the resistance increase rate also increases with the hydraulic diameter or porosity decreasing. The resistance and its growth rate become larger with the temperature increasing. For the same condition, the regenerator of square hole pattern has larger resistance. Based on experimental data, the monolith resistance experimental correlation is obtained.Finally, based on the experimental experience, recommendation which balanced in heat transfer and resistance performance of honeycomb regenerator for industry is given. The type of honeycomb regenerator which hydraulic diameter and porosity is moderate.hole pattern is circular is better.