采用局部非热平衡模型对石灰窑温度场的模拟及优化分析  

Simulation of the Temperature Field in a Lime Kiln by Using a Local Non-heat-equilibrium Model and Its Optimized Analysis

作　　者：刘国辉[1] 崔国民[1] 马尚策 韩娜[1] LIU Guo-hui;CUI Guo-min;MA Shang-ee;HAN Na(New Energy Science and Engineering Research Institute, Shanghai University of Science and Technology, Shanghai, China, Post Code ： 20009)

机构地区：[1]上海理工大学新能源科学与工程研究所

出　　处：《热能动力工程》2018年第2期96-105,共10页Journal of Engineering for Thermal Energy and Power

基　　金：国家自然科学基金(51176125);上海市科委部分地方院校能力建设计划(16060502600);沪江基金研究基地专项(D14001)~~

摘　　要：以某300t／d气烧石灰环形竖窑为研究对象，为获得其最佳运行工况并解决窑中煅烧温度分布不均匀的问题，采用数值模拟方法进行研究。将石灰石视为多孔介质、采用自定义标量方程（UDS）编译局部非热平衡模型、窑体中碳酸钙分解反应以源项的形式通过自定义函数（UDF）添加到整个反应过程中，获得的窑体中排烟和出料的模拟平均温度与实测值误差很小（〈15％），且石灰石固体和烟气的两相温度三带分布图符合实际煅烧过程的温度分布，验证了模拟计算的合理性；在此基础上，对燃料流量、助燃风流量和冷却风流量3参数进行单参数分别分析和正交试验分析。研究表明：燃料流量和冷却风流量对窑体温度场影响较强，而助燃风流量的影响较弱；石灰窑的最佳运行工况为燃料流量、助燃风流量和冷却风流量分别取0．1524、0．1067和0．1746kg／s。With a 300 t/d gas-fired lime annular vertical kiln serving as the object of study, to obtain the optimum operating condition and solve the problem of the ununiform distribution of the incineration tem- perature in the kiln, a numerical simulation method was adopted. With the limestone being regarded as a porous medium, by adopting an user-defined scalar （UDS） equation to prepare a local non-heat-equilibri- um model and incorporate the calcium carbonate decomposition reaction in the kiln into the whole reaction process as a form of the source items through an user-defined function, the errors between the average temperatures of the flue gases and outgoing materials simulated in the kiln and the actually measured val- ues were very small（ 〈 15% ） and the chart showing the two-phase temperature three-band distribution of limestone solids and flue gases were in agreement with the temperature distribution in the actual incinera- tion process. It has been verified that the simulation and calculation method is sound and rational. On this basis, a single parameter and orthogonal test analysis of the flow rate of the fuel, combustion-aided air flow rate and cooling air flow rate totaling three parameters were conducted respectively. It has been found that the fuel flow rate and cooling air flow rate will have a relatively strong influence on the temperature field in the kiln and the combustion-aided air flow rate will have a relatively weak influence. As a result, the optimum operating condition of the limestone kiln is chosen as follows： the fuel flow rate, combustion＇ai- ded air flow rate and cooling air flow rate being 0. 152 4,0. 106 7 and 0. 174 6 kg/s respectively.

关 键 词：石灰窑 多孑L介质 局部非热平衡 自定义标量(UDS) 自定义函数(UDF) 

分 类 号：TF061.2[冶金工程—冶金物理化学]