Coupled Gas Leakage and Heat Transfer Modeling in Tri-section Rotary Regenerator and Its Application

Abstract

Gas leakages take place in multiple sites in rotary regenerative air preheaters,governed by nonlinear equations of the matrix rotation,orifice flow between two infinite spaces,and mass and energy conservation in mixing processes.The gas flow rates through the matrix given by the leakage model are the basis for calculating heat transfer,the energy transport process in a rotary air preheater are mainly composed of carryover migration and convection heat transfer,gas temperatures outlet the preheater considered to be known in leakage calculation are solutions of the heat transfer model.it puts forward a combination of the model of rotary regenerator energy transport involving longitudinal matrix heat conduction,with a newly developed leakage calculation of a tri-section rotary regenerator for a theoretical analysis of the regenerator.The model provides precise calculations for rotary regenerators design.Performance under various sealing clearances are simulated in a tri-sectional rotary air preheater,the theoretical results are in good agreement with field experimental data,special attentions are focused on the influences of sealing settings on the leakage rate and gas temperatures outlet the air preheater,it clearly demonstrates that radial and axial leakages reduce flue gas temperature outlet the regenerator and increase the leakage rate,peripheral leakages increase the flue gas temperature outlet the regenerator and have little effect on the leakage rate,different distributions of leakages through radial,peripheral and axial seals have different effects on leakage rate and flue gas temperature outlet the regenerator.