蓄热式加热炉加热过程在线控制数学模型研究

蓄热式加热炉是一种蓄热式换热器与常规加热炉的结合体，整体结构包括炉体、蓄热室、换向系统、供风系统、排烟系统等。采用蓄热式燃烧技术，能够帮助加热炉达到更高的炉温，从而进行工业加热生产。蓄热式加热炉的优点在于能够使炉温分布均匀，根据不同需求对炉温进行调节，大大改善加热质量，提升加热产品的合格率。在全面分析蓄热式加热炉传热机理的基础上，建立了物理和数学的3D模型来描述炉内传热和加热过程。利用CFD软件对整个炉子的燃烧过程进行模拟。最后，对整个炉内的流动和温度曲线进行了深入研究，详细揭示了炉内的流动特性和温度分布规律，对蓄热式加热炉的合理设计和优化控制具有重要理论意义和实践价值。     

蓄热式加热炉用于特殊钢棒材加热的研究

针对蓄热式加热炉的特点,通过CAE分析手段,研究蓄热式炉型用于特殊钢棒材加热炉的可行性.并通过设计优化等措施,对于用蓄热式燃烧方式加热高品质特殊钢棒材进行了研究.     

蓄热式台车加热炉单一换向周期内燃烧特性数值研究

利用数值模拟技术,对蓄热式台车加热炉加热钢坯的燃烧过程进行了数学模拟实验研究,研究得出保温期末钢坯温度变化规律、某一换向周期炉内温度波动规律,模拟结果符合现场实际,对优化蓄热燃烧及加热炉设计操作具有指导意义.     

蓄热式加热炉数值模拟

以某长材厂蓄热式平顶加热炉为研究对象,根据工业应用现场的实际参数,利用Ansys软件采用k-ε湍流模型、P1辐射模型等模型进行数值模拟,分析加热炉内的流场、温度场和燃烧产物浓度的分布情况,发现同侧换向燃烧组织方式对炉内钢坯加热效果较好,且炉内温度梯度比较平滑,氧气浓度较低,与现场得到的实际数据进行对比,证明数值模拟的研究价值和适用性,并提出优化加热炉操作运行的可行性措施。     

300MW循环流化床锅炉稀相区的传热研究

本文针对燃烧煤矸石的循环流化床锅炉的传热情况展开研究,以山西平朔电厂1台300 MW的循环流化床锅炉为实例,采用环核模型和颗粒团更新模型,对稀相区的传热系数分布进行建模计算,本文所建模型考虑炉内床温实际分布特征,根据现场温度实测数据对模型进行修正,研究了对流和辐射换热系数在不同负荷下沿炉膛高度的变化情况。锅炉在较高负荷下运行时,负荷的波动对颗粒团壁面覆盖时均份额影响较小,继而对炉内对流换热影响较小。炉内环形区温度沿床高的偏差随负荷升高略有减小,且对辐射换热影响比对流换热大。随着负荷升高,对流换热系数沿炉高下降增大,而辐射换热系数沿炉高下降减小,高负荷时炉内总换热系数沿炉高下降25%左右,低负荷时沿炉高下降28%左右,高负荷下炉内沿高度温差更小,传热更稳定。     

燃料比对蓄热式加热炉热工过程的影响

建立了蓄热式加热炉数学模型,研究炉子结构参数及燃料一定时,沿炉长方向燃料比变化对加热炉热工过程的影响。在加热炉额定生产率下,分析了炉子第一、第二加热段和均热段燃料比变化对炉气、炉壁、钢坯上表面温度和钢坯断面温差等参数的影响,得出该加热炉的最优燃料比;研究了不同生产率下燃料比对加热炉热工过程的的影响,研究表明最优燃料比不随生产率变化而变化。该研究结果为优化蓄热式加热炉热工运行提供了重要的指导作用。     

蓄热式连续加热炉炉压分析与研究

蓄热式连续加热炉应用中存在着炉膛压力偏高且波动频繁等问题,其影响因素还有待研究。针对此现象对实际蓄热式加热炉进行理论分析,得知炉内气体流动状况是影响炉膛压力的主要因素,而换向方式对炉内气体流动状况有一定影响。通过对不同换向方式的模拟分析可以证实,蓄热式加热炉在其它条件不变只考虑换向方式不同时,沿炉宽方向分散换向比集中换向时炉压小。     

不同锭型及热负荷下均热炉内对流换热系数的模拟分析

均热炉是钢锭轧前加热过程的主要设备,其炉内的对流换热对于钢锭的加热过程有着很大的影响。文中以均热炉内对流换热过程为研究对象,通过对模拟研究得到了不同锭型在不同热负荷下加热过程中表面对流换热系数的变化情况,为钢锭加热过程工艺优化提供了基础。     

步进式加热炉内热工过程的数值模拟

建立步进式加热炉内流动、燃烧和传热的数学模型.炉内流场的模拟采用κ-ε双方程模型,辐射换热计算采用P-1辐射模型,气相燃烧采用Species Transport模型,流场计算采用Simpler算法.采用上述模型与算法得到了炉内详细合理的温度、速度和浓度分布,并对其中影响板坯加热的温度场进行了试验验证.     

分离型热管小倾角加热段换热性能的实验研究

对分离型热管小倾角加热段换性能进行了实验研究，得了合理的充液率范围和加热段换热关联式，讨论了倾角对平均换热系数的影响和局部换热系数的变化规律，其结果可供工程设计参考。     

A heat transfer model for the analysis of transient heating of the slab in a direct-fired walking beam type reheating furnace

A mathematical heat transfer model for the prediction of heat flux on the slab surface and temperature distribution in the slab has been developed by considering the thermal radiation in the furnace chamber and transient heat conduction governing equations in the slab, respectively. The furnace is modeled as radiating medium with spatially varying temperature and constant absorption coefficient. The steel slabs are moved on the next fixed beam by the walking beam after being heated up through the non-firing, charging, preheating, heating, and soaking zones in the furnace. Radiative heat flux calculated from the radiative heat exchange within the furnace modeled using the FVM by considering the effect of furnace wall, slab, and combustion gases is introduced as the boundary condition of the transient conduction equation of the slab. Heat transfer characteristics and temperature behavior of the slab is investigated by changing such parameters as absorption coefficient and emissivity of the slab. Comparison with the experimental work show that the present heat transfer model works well for the prediction of thermal behavior of the slab in the reheating furnace.     

提高炼油厂加热炉热效率的方法

加热炉的能耗问题是炼油厂中非常关键的问题。文章全面系统地介绍了提高加热炉热效率的方法：降低过剩空气系数；预热燃烧用空气和燃料气；利用对流室增加吸收热量；设计高效燃烧器；设置有效的吹灰器；减小加热炉漏风量；以及使用高温辐射涂层等。并且提出了提高加热炉热效率的新方法，即采用计算流体动力学(CFD)方法对加热炉内所发生的各过程进行数值模拟，在此基础上进行数值实验，最终确定最有效的提高加热炉热效率的方法。     

环形加热炉热工过程CFD数值模拟及其应用

借助CFD商业软件CFX，考虑流动、辐射、燃烧等，对宝钢环形加热炉的热工过程进行了数值模拟，得到了炉膛内的温度、速度矢量等热工参数的分布图。通过简化处理，对环形加热炉各控制段内的加热过程进行了模拟分析，并根据所得到的管坯表面辐射热流、热电偶温度及管坯表面温度研究了各个段总括热吸收率的分布情况，主要分析了总括热吸收率在管坯圆周方向、长度方向以及各个段之间的变化规律。     

Novel Approach to Estimate the Optimum Zone Fuel Mass Flow Rates for a Walking Beam Type Reheating Furnace

Three-dimensional numerical simulation is performed to predict the heat transfer performance in a walking-beam reheating furnace. The furnace uses a mixture of coke oven gas as a heat source to reheat the slabs. The fuel is injected into the furnace at four zones: preheating zone, first heating zone, second heating zone, and soaking zone. This numerical model considers turbulent reactive flow coupled with radiative heat transfer in the furnace; meanwhile, the conductive heat transfer dominates the energy balance inside the slabs. An initial iterative method is proposed to estimate the fuel mass flow rate at each zone of the reheating furnace, while the required heating curve of the slabs is specified. In addition, a simplified two-dimensional numerical model is performed to estimate the fuel mass flow rate for the consideration of computational time consummation. The results of the two-dimensional numerical simulations are compared with those of three-dimensional numerical simulation and the in situ data. Furthermore, velocity and temperature distributions are examined for two cases under different heating curves of the slabs.     

Flow of mixed convection for radiative and magnetic hybrid nanofluid in a porous material with Joule heating

This paper analyzes the mixed convection flow and transport of heat in a hybrid nanofluid via an exponentially extending/contracting surface. Joule heating, magnetic field, permeability of a porous medium, thermal radiation, and slip condition are taken into consideration. Magnetite (Fe₃O₄) and copper (Cu) are used as a mixture of nanoparticles while ethylene glycol as a regular liquid. The paradigm is dissolved by utilizing the method of Runge–Kutta–Fehlberg with the shooting technique in MATLAB software. The effect of controlling parameters on the coefficient of drag force, heat transfer coefficient, and the distributions of temperature and velocity for physical parameters are discussed numerically, physically, and graphically. The outcomes ended up illustrating that the transport of heat is diminished by upsurging the Joule heating and magnetic field parameters for both contracting and extending states. For larger values of permeability parameter and parameter of mixed convection, the coefficient of local skin friction upsurges in extending situations.     

侧燃式燃油棒坯加热炉

简介了550 t挤压机侧燃式油炉的结构与技术参数，提出风机是影响该炉型升温速度、加热效果及运行经济性的决定因素。简介了侧燃式炉热风发生装置的结构类型。加热装置的设置方式对加热效果有重要影响，在同等条件下，逆流加热装置的对流传热量是顺流加热装置的1.62倍。     

300MW循环流化床锅炉屏式受热面传热系数计算及其变化规律

根据300MW循环流化床（CFB）锅炉现场测试数据并结合以往CFB锅炉传热系数的研究成果,建立了屏式受热面烟气侧的传热模型,包括辐射传热模型和对流传热半经验公式．利用该模型对某300MWCFB锅炉在94％锅炉最大连续蒸发量（BMCR）工况下炉膛内屏式受热面的传热系数进行了计算,分析了屏式受热面管间节距、炉膛温度、工质温度、壁面黑度及烟气速度等因素对传热系数的影响．结果表明：烟气速度、炉膛温度和壁面黑度对传热系数的影响较大,所建立的传热模型能够合理地反映主要因素对CFB锅炉屏式受热面传热的影响．     

Investigation of the slab heating characteristics in a reheating furnace with the formation and growth of scale on the slab surface

In this work, the development of a mathematical heat transfer model for a walking-beam type reheating furnace is described and preliminary model predictions are presented. The model can predict the heat flux distribution within the furnace and the temperature distribution in the slab throughout the reheating furnace process by considering the heat exchange between the slab and its surroundings, including the radiant heat transfer among the slabs, the skids, the hot combustion gases and the furnace wall as well as the gas convection heat transfer in the furnace. In addition, present model is designed to be able to predict the formation and growth of the scale layer on the slab in order to investigate its effect on the slab heating. A comparison is made between the predictions of the present model and the data from an in situ measurement in the furnace, and a reasonable agreement is found. The results of the present simulation show that the effect of the scale layer on the slab heating is considerable.     

电窑制备SiC结合Si3N4材料加热阶段的数值模拟

电窑中SiC-Si3N4耐火砖的烧制过程按时间可分为三个阶段,即加热阶段、化学反应烧结及冷却阶段。用数值仿真的方法模拟加热阶段,分析窑内温度场的均匀性。发现窑内热棒的位置及供热功率变化对温度分布影响较大;窑内的对流换热对改善温度场,减小砖坯的表面温差有一定作用;由于发热棒的不合理布置,使得窑内的温度场均匀性较差,升温速率较慢,电窑热效率偏低。     

铝材退火炉退火过程的传热分析

根据箱式退火炉退火过程的传热特点,分析了铝箔退火炉退火过程各阶段炉膛内传热形式,建立了铝卷导热的数学模型,着重分析和计算了影响炉内空气与铝材间传热的重要参数——对流换热系数,并模拟计算了铝卷的退火过程和温度变化。结果表明,铝卷退火曲线计算值与实测值结果比较吻合。