Study On Single-channel Heat Transfer Of Regenerator In Treatment Of Volatile Organic Gas

Volatile Organic Compounds(VOCs)are common pollutants in the atmosphere.They are also important precursors for the formation of PM2.5 and ozone.They cause great harm to the environment and human beings.Among the many VOCs treatment methods,the Regenerative Thermal Oxidizer(RTO)is widely used in recent years because of its high VOCs removal rate and thermal efficiency.The regenerator,as one of the most critical components in the RTO,its physical parameters not only directly determine the thermal efficiency and economic efficiency,but also affect the selection of the regenerator size and RTO operating parameters.Therefore,the regenerator heat transfer study has very profound significance.This paper studied the heat transfer performance of regenerator single-channel in the VOCs processing with three-chamber RTO.Firstly,RTO industrial experiments were conducted and the accuracy of simulation methods by N.Radifi’s results and industrial experiments was verify.Simulate and compare different models and the simulation method and model adopted in this paper were determined.Secondly,the three heat transfer processes of the regenerator were analyzed using the verification condition of the industrial experiment,that were,the exothermic period that flue gas released heat to the regenerator,the heating period that exhaust gas containing VOCs was heated by regenerator and the backflushing period that the air was heated by the regenerator.The variation law of velocity field and temperature field of the regenerator in a cycle was obtained.Based on numerical simulation calculations,the effects of key parameters of the regenerator(density,specific heat,wall thickness,channel length,regenerator length,air volume,valve switching time,backflush volume)on heat transfer performance of regenerators such as gas outlet temperature,energy recovery rate,heat transfer capacity and heat transfer coefficient were discussed by numerical simulation.The regularities of single factor on each heat transfer performance index were obtained.Based on the BBD test design method in response surface analysis,a five-factor and three-level text was designed,and study the influence of the five physical and structural parameters of the regenerator on several performance parameters using the numerical simulation method.A regression model with good fitting degree was obtained.The influence of the physical and structural parameters of the regenerator on the heat transfer performance index of the regenerator was studied.The results show that the channel length had the greatest influence on the gas outlet temperature,energy recovery rate,heat transfer capacity and heat transfer coefficient among the five physical structural parameters.The interaction between the channel length and the regenerator length had the most significant effect on the average gas outlet temperature,energy recovery rate and heat transfer capacity.