Analysis On Thermal Performance And Optimum Design Of Ball Packed Regenerator

High Temperature Air Combustion technology (HTAC) is a new combustion technology sprang up from the90s last century, it integrates utmost reclamation of waste heat of flue gas, high efficiency combustion of gas, and low emission of NOx into a new technology, there are some advantages in HTAC, such as energy saving, environmental protection, and decreasing the scale of furnace, and so on, now it has made a rapid progress in the last year. Regenerator is the most important part of HTAC technology, in this paper, the thermal performance and optimization design of ball packed regenerator has been made special study.The mathematical model is established which is based on the thermal process in the ball packed regenerator by consulting a large number of domestic and foreign literature, and a set of manually operable numerical calculation software has been developed by using Visual Basic computer language, in view of the different design parameters, the mathematical model has been solved, and obtains that the regenerator material, the tye of gas, the regenerator chamber structure parameter and operation parameter are the main influence factors of regenerator thermal characteristics, the main conclusions as follows:(1) In the same situation, the larger the heat storage capacity of regenerator is, the lower the temperature of flue gas outlet is, the higher the temperature of air outlet and the efficiency of heat transfer is, and the heat storage capacity is larger, the heat exchange efficiency of regenerator and the outlet temperature of gas change fluctuation is relatively smooth;(2) In the single preheating condition, the outlet temperature of flue gas can be reduced to below200℃when burning high calorific value gas, but the outlet temperature of flue gas can not be reduced to below200℃when burning low calorific value gas, no matter how increase the regenerative chamber height, shortening the commutation time;(3) With the increase of diameter of ball, the outlet temperature of flue gas increase, the outlet temperature of air and heat exchange efficiency of regenerator decrease; with the increase of height of regenerator, the outlet temperature of flue gas decrease, the outlet temperature of air and heat exchange efficiency of regenerator increase; with the increase of velocity of gas, the outlet temperature of flue gas increase, the outlet temperature of air and heat exchange efficiency of regenerator decrease; with the prolonged of reversing time, the outlet temperature of flue gas increase, the outlet temperature of air and the heat exchange efficiency of regenerator increase first and then decrease, so there exists an optimal switching time for the regenerator which structure and flow rate have been identified.(4) The decrease of ball diameter, the increase of regenerator height and gas velocity, will cause the ball bed resistance loss increase, led to fan and other power equipment energy consumption increase, so various factors should be taken into consideration when design a regenerator;At last, a set of ball packed regenerator optimum design software has been developed by using constraint method, under allowable pressure loss, in order to obtain the best effect of heat transfer as the target, the optimum structural parameters and operational parameters are obtained. Through the engineering practice, the heat exchange efficiency of ball packed regenerator under meeting the engineering requirements by using this software is higher, it can be used as the foundation of reasonable structural design for designers, reduces unnecessary human error, and saves a large amount of computing time.The work in this paper provides a theory basis and guide to the application of ball packed regenerator, and the results of the numerical calculation can be used as the foundation of engineering design.