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本文介绍了喷流换热装置在轧钢加热炉上的研制、设计和使用情况。该装置用高温风机将换热器后的烟气加压喷射到炉内钢坯表面上,将传热系数提高到120~180 kcal/(m~2·h·℃),在4m长的喷流段内将钢坯预热至200℃左右,相当于延长预热段2~3倍的效果。现已运行一年半,运转正常,单耗降至0.325×10~6kcal/t,进入特等炉。 相似文献
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在加热炉的各项热损失中,所占比例最大的是烟气热损失,约占总热量的1/3~1/2。因此,尽量减少和充分利用炉膛废气,乃是加热炉节能的关键。延长加热炉预热段,可以利用炉内烟气预热钢坯,提高炉子热效率。然而,延长预热段长度受到炉底强度、废气温度、烟囱抽力和技术经济效果等因素的影响,必须视加热炉具体情况确定。 相似文献
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钢坯连续加热炉动态操作与优化控制的数学模型 总被引:2,自引:1,他引:1
本文建立了钢坯连续加热炉内钢坯加热过程的数学模型,提出以钢坯焓增过程积分值为目标函数,求取优化炉温制度的新方法。着重研究了待轧过程,得出了合理的待轧策略。开发了在线控制数学模型,通过动态补偿得出加热炉实时优化炉温设定值,使出炉钢坯温度与目标温度的偏差小于15℃,实现了加热炉的高产,优质和低耗。 相似文献
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为了回收利用推钢式加热炉的低温烟气(400℃以下)余热,作者提出了在加热炉预热段炉顶安装喷流装置以提高预热段的对流给热能力。通过实验室进行的模拟喷流热态试验,取得了较好的结果。当炉温为750~950℃范围内,喷流气体温度为370℃时,平均热流可提高约26.0%,综合传热系数可提高52.0~66.0%。 相似文献
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加热炉能耗约占热轧工序的75%,金属损失达到全工序的50%,具有很大的研究潜力。目前针对加热炉钢坯混装以及烧嘴旋流的复杂情况研究相对较少,难以精确反映加热炉内钢坯加热过程。基于计算流体力学方法建立了加热炉燃烧场与钢坯耦合传热的数学模型,研究钢坯长度方向温度分布及在旋流烧嘴及混装条件下的长钢坯在加热炉内的加热情况。结果表明,模拟值与实际值温差小于10 K。钢坯出炉时上表面和下表面最大温差分别为23和22 K,上下表面最大温差为8 K,能够满足钢坯长度方向温差小于30 K的生产需要。旋流效果在被烧嘴通道一定程度上被削弱。火焰根部温度较低易造成钢坯端头低温。 相似文献
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加热炉能耗占钢铁企业总能耗的15%~20%,占轧钢过程能耗的70%,具有很大的研究价值。基于计算流体力学方法建立数学模型,研究双排料步进式加热炉中钢坯的加热过程,通过对比模拟结果与黑匣子数据,验证模型的可行性。根据炉内钢坯沿炉长方向各热通量的变化,研究了炉壁各区域和炉膛发射率对钢坯加热过程的影响。结果表明,提高炉壁发射率对钢坯平均温度影响较小,但对钢坯温差有显著影响;而壁面发射率由0.75提高到0.95时,钢坯的最佳驻炉时间可减少5%~12%;相比于一加段和均热段,烟气预热段、预热段和第2加热段壁面发射率的增加对钢坯加热过程影响更大。综合考虑经济成本和生产效率,现场可以通过在烟气预热段、预热段、第2加热段炉壁应用发射率为0.85的涂层,以增强炉内辐射换热,提升钢坯加热质量。研究结果为加热炉实际生产提供了理论依据。 相似文献
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针对如何强化连续轧钢加热炉预热段对钢坯传热的实际问题,根据传热学原理,提出了在预热段增设辐射传热体的新思想,并在实际生产中应用。实践证明:辐射传热体对改善钢坯加热质量、降低燃耗有较好的效果。 相似文献
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《Baosteel Technical Research》2010,(Z1):101
Furnace area is regarded as looper between casting and hot rolling,which is very important for material flow balance and production organization as well as temperature regulation etc.In particular,when dealing with energy saving and emission reduction and heating quality improving,pre_heating furnace is paid more attention.The radical target for preheating furnace is to transfer heating energy at the least cost. As we know,the preheating furnace is a dissipation system to obey conservation of energy law,that is to say that input energy always equals to output energy,in the meantime,the whole energy consuming is not reversible.Therefore increasing the efficiency of using energy is uppermost.In this paper,heating transfer efficiency is analysed and mathematical expression is given based on conservation of energy law.Typical optimal methods to improve preheating furnace transfer efficiency coming from foreign factories are presented.According to these methods,every furnace zone temperatures as control variable,target discharging temperature and temperature difference in slab thickness and the temperature between neighbouring zones as well as zone temporary temperature as restrictions,minimal energy consuming as optimizing target.Baosteel preheating furnace model structure and the complicated mapping relation of control parameter set and state set and aim set are presented.Important basic models in the preheating furnace model system are analysed including temperature tracking model and temperature forecasting model and discharging pacing model and slab heating curve.First slab temperature model structure and its peripheric parameter are introduced;second two pacing models are given including timing pacing mode using fixed discharging interval and mill pacing control mode using mill rolling pacing while Baosteel pacing forecasting model using long term and short term forecasting mode) is given;third a heating curve mathematical model considering heating quality and rolling pace and energy consuming is presented;in the end summary is done and the future way is lighted.Baosteel heating model including slab and billet and steel ingot have been developed,the actual applications show a good effect.The future woks include working procedure saving energy and system saving energy considering " Oder and rule" to achieve system harmony and rhythmization.Baosteel Blooming furnaces scheduling system is very useful for smooth production and saving energy. 相似文献
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���� ���¿� ���»��� ����ΰ ����� 《钢铁研究学报》2014,26(10):21-25
A 2D temperature model was proposed for heating rules and real-time calculation during heating process on billet reheating furnace, which included furnace temperature calculation along furnace length, billet surface fluxes calculation and conduction calculation inside billet. First, furnace temperature was accomplished according to thermocouple. Then fluxes on the above and below surfaces were calculated by total heat exchange factor method, as well as lateral fluxes. ADI and TDMA algorithms were adopted to calculate billet internal temperature distribution. Validation was carried out by thermocouple experiments and a model system was established in a hot rolling plant to provide appropriate heating rules and real-time temperature prediction. It shows precision and responsibility during reheating furnace production. 相似文献
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FAS2225钢(/%:0.26C,0.35Si,1.99Mn,0.013P,0.046S,0.54Cr,0.12V,0.02Mo,0.08Ni,0.0012O,0.0070N)的生产流程为铁水预处理-60t顶底复吹转炉-LF-VD-300mm×360mm坯连铸-连轧。在215mm×213mm轧坯上出现中心开裂形成孔洞。经分析得出,加热速度过快及温度梯度过大产生的热应力和组织应力使连铸坯发生开裂造成轧制过程孔洞缺陷。通过预热段加热温度从900℃降至750℃,延长加热时间、温度梯度从△200℃降至△100℃有效遏制了孔洞缺陷的产生。 相似文献
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介绍了蓄热式燃烧技术在青钢钰尊高线步进梁式加热炉设计中的应用情况。加热炉燃烧系统分三个供热段,采用分隔式空、煤气双预热烧嘴.直通道蜂窝体蓄热体,通过换向系统,实现了“极限余热回收”和高温空(煤)气预热。投用后,加热炉满足节能、无公害及生产操作自动化程度高的要求,钢坯加热温度均匀,吨钢燃耗1.4GJ,氧化烧损率约为0.7%。 相似文献