高焦混合煤气代替发生炉煤气使用中存在的问题及处理

１前言 我厂原发生炉煤气站是１９７２年建成并投产的，有４台煤气发生炉，平时开二备二，产冷净发生炉煤气１．４万ｍ３／ｈ，供给本厂生产使用。冷净发生炉煤气热值约６．０ＭＪ／ｍ３，该煤气站在国内属中小型规模的煤气站，其能源费、环保治理费、设备费等总成本费用高达９８６万元．为了节能降耗、减污增效，太钢公司决定回收南区的高炉煤气，但因高炉煤气热值较低，需配入适量的焦炉煤气，以代替我厂煤气站生产的发生炉煤气． 从１９９８年７月份开始，我厂锻造加热炉、退火炉正式使用了公司的高焦混合煤气，同时运行了２７年的发生炉…     

300MW烟煤/高炉煤气混燃锅炉掺烧褐煤燃烧特性的数值模拟及经济性分析

对某300MW烟煤/高炉煤气混燃锅炉掺烧褐煤的燃烧特性进行数值模拟和经济性分析,分析了褐煤完全取代烟煤、部分掺烧褐煤和不同高炉煤气掺烧比例等因素对炉内温度场和CO摩尔分数分布的影响.结果表明:褐煤完全取代烟煤后,炉内温度显著降低而炉膛出口烟气温度明显升高,影响了锅炉运行的安全性;褐煤取代部分烟煤后,随着褐煤掺烧比例的增大,炉内温度逐渐下降,炉膛出口烟气温度升高但CO摩尔分数变化不大;在褐煤掺烧比例一定时,随着高炉煤气掺烧比例的增大,炉膛最高温度明显降低且炉膛出口温度升高,CO摩尔分数的峰值逐渐减小;纯烧烟煤的发电成本为117 090元/h,当掺烧40%褐煤和20%高炉煤气时,发电成本降为80 107元/h,发电成本比纯烧烟煤降低了31.59%.     

某管式炉改烧高炉煤气的改造思路及数值模拟

为了能减少高炉煤气的放散,充分利用高炉煤气资源,对某钢厂的管式加热炉提出添加高炉煤气作为燃料的改造方案。提出了在原管式炉下方区域增加圆筒形绝热燃烧室,采用焦炉煤气与高炉煤气两用燃烧器以及侧喷切圆燃烧技术等手段来保证改造成功,同时针对改造方案进行了一系列数值模拟。模拟结果表明改造方案切实可行,采用侧喷切圆燃烧方式能显著提高燃烧室出口截面温度均匀性。即使完全燃烧低热值的高炉煤气,也能保证燃烧室中气体的稳定燃烧。     

浅谈一台180 t/h中温中压高炉煤气锅炉的设计

深入分析了高炉煤气的特性、燃烧机理.介绍了笔者针对其特性研制的180 t/h中温中压高炉煤气锅炉,该锅炉通过设置炉内蓄热稳燃器、预热空气、采用单汽包炉型等方法实现了高炉煤气的有效利用.     

高炉煤气锅炉富氧助燃的特性研究

以国内某钢铁企业220t/h高炉煤气锅炉为研究对象,利用计算流体力学软件Fluent,简化了几何结构模型,在助燃空气量恒定情况下模拟了3种不同加氧量的高炉煤气锅炉炉内流动及燃烧过程,得到了锅炉炉内速度和温度分布.模拟结果表明:加入氧气后锅炉炉内气流动力场没有受到影响,随着加入氧气量的增加,整个炉膛内烟气温度增加,火焰温度更为集中,高温区减小.在加入的氧气量仅为2000m3/h时,炉内温度增加不明显,当加入氧气量达4000m3/h后,炉内温度增加明显,烟气辐射特性增强,壁面热负荷值也有明显增加.当加入氧气量达到6000m3/h时,炉膛壁面热负荷最大值达到103158W/m2,燃烧器喷口附近温度升高明显,燃烧器喷口附近温度过高有可能会对燃烧器产生烧损.     

浅谈一台100t/h中温中压高炉煤气锅炉的设计

深入分析了高炉煤气的特性、燃烧机理,介绍了针对其特性研制的100t/h中温中压高炉煤气锅炉,该锅炉通过设置炉内蓄热稳燃器、预热空气、采用双汽包炉型等方法实现了高炉煤气的有效利用.     

煤粉锅炉掺烧高炉煤气对煤粉燃尽影响的研究

针对某钢铁企业实际燃用的燃料，计算得到了高炉煤气掺烧率变化引起的烟气生产量变化和燃料理论燃烧温度变化曲线，在此基础上分析了高炉煤气掺烧对煤粉燃尽影响的各种因素，其中煤粉在炉膛内停留时间缩短、炉膛温度水平下降是最主要的因素。通过在一维炉和滴管炉上进行的温度对该种煤粉燃尽影响的试验研究，分析了高炉煤气掺烧率超过20%时飞灰可燃物含量急剧上升的原因，从而提出基于燃尽的煤粉锅炉掺烧高炉煤气的最佳热量掺烧率应该在25％左右。图5表3参6     

预热空气与高炉煤气的扩散燃烧混合特性研究

针对某钢铁企业高炉煤气回收水冷系统的特点,分析研究了低热值高炉煤气与不同预热温度空气的同轴扩散气流在绝热炉膛内混合和燃烧的特点,据此建立k-ε双方程燃烧数学模型,并对其燃烧混合特性进行模拟研究.研究结果表明:回流中心区的位置位于轴向0.1～0.22 m,但随着空气预热温度的升高,缩小到0.12～0.2 m,回流负压也有...     

加热方坯、圆坯蓄热推钢式连续加热炉的开发和实践

采用推棒措施，实现方坯、圆坯均可在推钢式连续加热炉内加热。采用高炉煤气、空气双蓄热式预热至高温，以满足炉温要求，并显著节能。炉子还集成了炉底管汽化冷却、复合不定型耐火材料筑炉、热工自动控制等技术。     

全燃高炉煤气的轧钢加热炉

一、概述南京钢铁厂第三轧钢分厂有一座有效面积78米~2的三段连续式加热炉,加热坯料为60×60毫米~2、75×75毫米~2、90毫米~2方坯,小时加热能力30～35吨。加热炉原采用7527千焦/米~3的高、焦炉混合煤气,使用高压喷射式烧嘴,并专门配备了一座煤气加压站。炉子保温时,炉前常常将加压后的多余煤气放散,不仅浪费了大量能源也污染了周围环境。为节约能源,1987年初,结合炉子大修,由冶金部马鞍山钢铁设计研究院设计,将该炉改造成了国内中型加热炉中第一座全燃高炉煤气的轧钢加热炉。     

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.     

连续重整装置四合一加热炉节能改造

针对某公司2. 0 Mt/a连续重整装置四合一炉排烟温度高、加热炉燃烧效率低的问题,增设落地省煤器,通过烟气与锅炉除氧水换热,烟气排烟温度由190℃降至120℃,加热炉燃烧效率由89. 83%提高至93. 01%,锅炉增产3. 5 MPa,蒸汽5. 5 t/h,创造经济效益868万元/年。同时针对项目改造后出现的锅炉给水阀故障和除氧器压控阀开度过小问题进行原因分析并提出了解决方案。该项目的成功运用,为同类装置的改造提供宝贵的借鉴经验。     

连续式轧钢加热炉在线控制数学模型与应用

以理论计算和实测数据为依据,开发了连续式加热炉最佳炉温设定和在线控制数学模型,并应用于安钢中型厂5点供热推钢式加热炉。结果表明：在轧机产量波动时,不但加热炉供热合理,而且钢温波动小、加热质量好、节能效果显著。     

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.     

Efficiency analysis of radiative slab heating in a walking-beam-type reheating furnace

The thermal efficiency of a reheating furnace was predicted by considering radiative heat transfer to the slabs and the furnace wall. The entire furnace was divided into fourteen sub-zones, and each sub-zone was assumed to be homogeneous in temperature distribution with one medium temperature and wall temperature, which were computed on the basis of the overall heat balance for all of the sub-zones. The thermal energy inflow, thermal energy outflow, heat generation by fuel combustion, heat loss by the skid system, and heat loss by radiation through the boundary of each sub-zone were considered to give the two temperatures of each sub-zone. The radiative heat transfer was solved by the FVM radiation method, and a blocked-off procedure was applied to the treatment of the slabs. The temperature field of a slab was calculated by solving the transient heat conduction equation with the boundary condition of impinging radiation heat flux from the hot combustion gas and furnace wall. Additionally, the slab heating characteristics and thermal behavior of the furnace were analyzed for various fuel feed conditions.     

环形加热炉炉温在线分段寻优策略研究

以环形加热炉在标准产量下满足加热质量要求为前提,以燃耗和氧化烧损最低为目标,通过离线优化研究,得到了标准产量下不同管坯的最优升温曲线。在环形加热炉数学模型优化控制系统中,以管坯最优升温曲线为基础,对炉温进行分段在线寻优,取得了良好的控制效果。     

A Coupled Numerical Study of Slab Temperature and Gas Temperature in the Walking-Beam-Type Slab Reheating Furnace

In the present study, a three-dimensional simulation is performed for the turbulent reactive flow and radiactive heat transfer in the walking-beam-type slab reheating furnace using STAR-CD software. The geometric model takes care of all components of the furnace. To obtain a steady solution, the walking beams are assumed fixed in the furnace and the slab is modeled as a laminar flow having a very high viscosity and thus moving at a nearly constant speed. The temperature distributions of the slab and the gas mixture are obtained through a coupled calculation. The simulation results successfully predict the temperature distribution inside the slab and the heat flux on the slab surfaces, providing an opportunity for a full exploration of the influence of the walking beam system on the skid marks. The simulation results show that the radiative shielding by the static beams is the main cause of the skid marks. The heat loss through the skid button to the cooling system worsens the skid marks.     

大型热轧加热炉内连铸板坯加热温度的测试

介绍了连铸板坯在加热炉内加热实际温度测试的设备和方法，以实例分析温度测试在加热炉功能考核、数学模型参数提取、数学模型验证和故障诊断方面的应用。     

日本高性能工业炉的开发战略与实施进展

介绍日本斥资86亿日元,对范围涉及加热炉、热处理炉、熔化炉等工业炉所实施的高性能工业炉开发与适用试验的进展情况。     

轧钢加热炉富氧燃烧过程的数值研究

借助数值模拟方法研究了不同气氛、氧浓度以及燃料热值对加热炉燃烧特性以及Nq排放的影响规律。结果表明：富氧燃烧能提高炉膛燃烧温度,使炉壁辐射换热量NJJtt约5．2％,排烟热损失减小约21．7％。相同富氧浓度条件下,空气气氛下炉膛燃烧温度更高,炉壁辐射换热量增加约5％,排烟损失减少24％以上;但OjCOz气氛下钢坯表面传热特性改善,断面温度分布更加均匀,Nq排放量降低为空气气氛的1／10以下。