三分仓回转式空气预热器泄漏和传热耦合计算  

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

作　　者：刘福国[1] 史昱[2] 

机构地区：[1]山东电力研究院,济南250002 [2]山东交通学院数理系,济南250021

出　　处：《机械工程学报》2012年第14期148-155,共8页Journal of Mechanical Engineering

摘　　要：回转式预热器的气体泄漏发生在多个部位,由大空间之间的小孔流动、携带泄漏、质量和能量守恒组成的非线性方程组描述,泄漏模型确定的流过传热元件的气体流量是传热计算的基础;回转预热器的热量传递包括携带迁移和对流换热两个过程,传热模型确定的气体出口温度是泄漏计算的必要数据;采用考虑轴向导热的二维的偏微分方程描述三分仓回转式预热器的热量传递,该方程与泄漏模型的多维非线性方程构成泄漏和传热耦合模型,给出耦合模型的求解方法,它提供更为精细的回转式预热器设计计算方法。对一台实际运行的三分仓回转式预热器不同密封间隙下的性能进行模拟,并将理论计算值和实际测量数据进行对比,结果表明,模型有较好的精度;径向和轴向泄漏会降低锅炉排烟温度,使预热器漏风率增大;旁路漏风会引起锅炉排烟温度增加,但对预热器漏风影响很小;预热器不同部位的泄漏对漏风率和锅炉排烟温度有不同影响。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.

关 键 词：回转式预热器 再生换热 泄漏 泄漏和传热耦合计算 

分 类 号：TK222[动力工程及工程热物理—动力机械及工程]