焦炉直行温度数学模型及其在宝钢三期焦炉中的应用实践

在详尽分析了宝钢三期焦炉热工工艺特点的基础上，建立了焦炉直行温度数学模型。采用现场实测的立火道温度对所建立的数学模型进行了验证，在此基础上仿真计算了不同工况对焦炉直行温度和加热煤气流量等主要热工参数的影响，所做工作为焦炉的计算机优化加热控制奠定了坚实的理论基础。     

石家庄焦化厂焦炉加热采用计算机模糊控制系统

石家庄焦化厂焦炉加热采用计算机模糊控制系统石家庄焦化厂与北京科技大学联合在国内首次将模糊控制理论应用于焦炉加热过程控制，并进一步把系统扩展为生产控制机与上位管理机综合为一体的生产、管理优化管理系统。该系统对焦炉直行平均温度控制，空气过剩系数的控制，焦...     

焦炉上升管换热器传热特性的模拟研究

为了解决焦炉荒煤气显热回收中受热面换热效果差、易结焦等问题,以某钢厂一期焦炉加装夹套管式换热器后的上升管为物理模型,使用Fluent软件对其进行数值模拟,研究显热回收过程中上升管内部的换热规律。结果表明:适当提高荒煤气入口流量和入口温度有助于减轻焦油附着问题,但随着荒煤气入口流量的增加和入口温度的降低,上升管换热器的热回收效率降低,综合考虑热回收效率与焦油附着问题,同时保证换热器运行参数稳定,建议将多座焦炉并行生产,且维持荒煤气入口流量为500 m~3/h不变,尽量提高其入口温度。此外,上升管前1 m段热应力较大,应采取一定措施以防止其造成上升管内壁损伤。     

焦炉荒煤气重整提质制氢的热力学分析

为了验证吸附强化焦炉荒煤气重整制氢工艺的可行性,并为相关的实验研究提供理论依据,文章采用HSC Chemistry软件对焦炉荒煤气全组分蒸汽重整反应进行热力学分析,研究反应温度、反应压力、S/C,CaO/C对H_2产率、浓度等的影响。研究结果表明:焦炉荒煤气蒸汽重整反应能够有效地脱除焦油组分,随着S/C的增大,H_2产率会得到明显提升,且最佳H2产率所对应的反应温度会随之降低,当S/C为5∶1,反应温度为700℃时,H_2产率为1.62 mol/mol,但H_2浓度仅为75%左右;CO_2吸附剂的加入会强化蒸汽重整反应,H_2产率、浓度均会显著提升,最佳重整反应区的反应温度会随之降低,当反应温度为500~600℃,S/C为5∶1,CaO/C为3∶1时,H2产率、浓度能够分别达到1.83 mol/mol,98%以上。     

焦炉荒煤气上升管余热回收换热器换热特性研究

为了研究焦炉荒煤气上升管余热回收换热器的换热特性,建立新型荒煤气余热回收换热器的换热数学模型。基于所建的焦炉荒煤气余热回收换热器换热模型对其换热特性与动态调节特性进行初步理论研究。获得了荒煤气流量、导热油流量与填料层有效热导率对换热器换热特性的影响规律与不同荒煤气上升管出口设定温度下,导热油流量及其出口温度随荒煤气流量的变化规律。所的结果对焦炉荒煤气余热回收换热器换热特性的认识及换热器的设计、动态调节具有重要的指导意义。     

改造初冷器收到节能效果

<正> 国内焦化厂的初冷器,绝大多数是一段冷却。为保证工艺参数,使煤气能有较低的集合温度,初冷水出口温度一般只能维持在摄氏五十多度。在东北地区利用这样温度的热水采暖,根本满足不了要求。如果提高初冷水温室,就必然使煤气的集合温度升高,又影响了焦炉的正常生产。所以长期以来,这个低温热源没能得到很好的利用。     

混合煤气成分变化对加热炉内温度场影响的数值模拟研究

以燃用高炉、焦炉混合煤气的实验加热炉为研究对象,建立炉内二维稳态传热、流动及燃烧的数学模型,研究混合煤气成分变化对加热炉内温度场的影响,计算结果显示高炉煤气含量在一定范围内增加时,炉内温度水平和钢坯加热区温度均匀性逐渐降低.这些与华凌涟钢集团轧钢加热炉的实际情况基本一致.     

CO催化变换制氢反应机理及传统变换催化剂研究进展

为简化焦炉气制氢流程,提出了利用水煤气变换反应将焦炉气中CO转化为H2和CO2的技术方案。该技术使变换后的气体组成简单易于分离,其关键是开发或优选以焦炉气为原料的CO变换催化剂。基于文献分析,讨论了国内外CO变换反应机理、CO高变催化剂和低变催化剂的研究现状及进展,旨在为开发焦炉气中CO转化的水煤气变换催化剂奠定基础。     

焦炉余热利用技术状况及发展方向

焦炉余热利用技术状况及发展方向牛泽群（冶金工业部能源办，北京，１００７１１）１焦炉余热资源炼焦生产有着大量的余热余能资源，焦炉热支出绝大部分都是可利用的余热。我国焦化生产工序能耗为１８０～２００ｋｇ（标煤）／ｔ，其中焦炉生产的能耗在７５％以上，而焦炉...     

焦炉荒煤气余热回收研讨及实验

介绍梅钢炼焦分厂的焦炉煤气余热回收研究工作,对焦炉荒煤气余热回收相关问题进行了研讨与实验,开展了传热分析与模拟计算,并进行了焦炉上升管热量回收实验系统与装置的设计和试验,为以后相关焦炉荒煤气余热回收利用奠定了基础。     

Applying the multi-zone model in predicting the operating range of HCCI engines

In this paper, a multi-zone model is developed to predict the operating range of homogeneous charge compression ignition (HCCI) engines. The boundaries of the operating range were determined by knock (presented by ringing intensity), partial burn (presented by combustion efficiency), and cycle-to-cycle variations (presented by the sensitivity of indicated mean effective pressure to initial temperature). By simulating an HCCI engine fueled with iso-octane, the knock and cycle-to-cycle variations predicted by the model showed satisfactory agreement with measurements made under different initial temperatures and equivalence ratios; the operating range was also well reproduced by the model. Furthermore, the model was applied to predict the operating range of the HCCI engine under different engine speeds by varying the intake temperatures and equivalence ratios. The potential to extend the operating range of the HCCI engine through two strategies, i.e., variable compression ratio and intake pressure boosting, was then investigated. Results indicate that the ignition point can be efficiently controlled by varying the compression ratio. A low load range can be extended by increasing the intake temperature while reducing the compression ratio. Higher intake temperatures and lower compression ratios can also extend the high load range. Boosting intake pressure is helpful in controlling the combustion of the HCCI engine, resulting in an extended high load range.     

Applying the multi-zone model in predicting the operating range of HCCI engines

In this paper, a multi-zone model is developed to predict the operating range of homogeneous charge compression ignition (HCCI) engines. The boundaries of the operating range were determined by knock (presented by ringing intensity), partial burn (presented by combustion efficiency), and cycle-to-cycle variations (presented by the sensitivity of indicated mean effective pressure to initial temperature). By simulating an HCCI engine fueled with iso-octane, the knock and cycle-to-cycle variations predicted by the model showed satisfactory agreement with measurements made under different initial temperatures and equivalence ratios; the operating range was also well reproduced by the model. Furthermore, the model was applied to predict the operating range of the HCCI engine under different engine speeds by varying the intake temperatures and equivalence ratios. The potential to extend the operating range of the HCCI engine through two strategies, i.e., variable compression ratio and intake pressure boosting, was then investigated. Results indicate that the ignition point can be efficiently controlled by varying the compression ratio. A low load range can be extended by increasing the intake temperature while reducing the compression ratio. Higher intake temperatures and lower compression ratios can also extend the high load range. Boosting intake pressure is helpful in controlling the combustion of the HCCI engine, resulting in an extended high load range.     

基于偏最小二乘回归法的电站锅炉炉膛出口烟温调整试验研究

针对某电厂的锅炉炉膛出口烟温进行了调整试验.通过数据预处理和偏最小二乘回归分析,建立了炉膛出口烟温的统计学模型.通过分析模型的影响因子,进行了运行参数的调节,给出了不同负荷下锅炉的合理运行工况.试验结果表明:通过调节炉膛出口烟温,可提高燃烧效率,减少煤耗.利用偏最小二乘回归方法分析试验数据,有助于调试人员掌握被调对象的运行特性,且便于寻找最佳工作点.     

深度调峰工况下锅炉过量空气系数对炉内温度影响的分析

  [目的]  为了分析火电机组超低负荷运行工况下过量空气系数对于炉膛燃烧稳定性的影响,更好地指导机组参与调峰。  [方法]  通过深入分析锅炉运行和炉内传热机理,以炉膛出口烟温表征炉内燃烧温度,并作为燃烧稳定性的指标,在MATLAB/SIMULINK中搭建炉膛出口烟温模型。以某300 MW火力发电机组为例,首先选择几个典型工况点采用相似性求解方法计算炉膛出口烟温与锅炉厂家给出的设计数据进行比对,检验计算方法基本正确之后代入超低负荷运行参数,计算深调峰工况下不同过量空气系数对应的炉膛出口烟温。  [结果]  仿真结果表明:模型算得炉温与锅炉厂家给出的设计数据对比,计算误差小于±15 ℃,计算方法基本正确,可以将其应用于超低负荷工况计算。  [结论]  随着负荷的降低,使炉膛出口烟温达到最大值的最优过量空气系数逐渐增大。因此在超低负荷运行工况下,可在一定范围内适当增大过量空气系数以提高炉膛出口烟温,进而提高锅炉燃烧的稳定性,并且过量空气系数小于2.0时,数值越大炉膛出口烟温越高。     

Modeling and countermeasures of combustion characteristics of char particles in CFBC

INTRAODUCTIONAsahigh-efficiencyandcleancoalcombustiontechnology,circulatingfluidizedbed(CFB)combustiontechnologyachievesrapiddevelopmentinChinaforburningvariouslow--gradefuels.ThescalerupofCFBboilersbecomesakeypointconcernedbytheCFBboilerdesigners.At...     

A new generalised model for liquid film cooling in rocket combustion chambers

A one dimensional analytical model of liquid film cooling in rocket combustion chambers operating at subcritical conditions is developed. The approach followed involves the selection of a control volume for mass and energy balance. The coolant evaporation rate per area is obtained from this energy balance. The present model incorporates mass transfer via entrainment by adapting suitable correlations from literature pertaining to annular flow conditions. The model predicted favourably with the experimental data available in open literature and produced superior results compared to all existing models. Results are presented for a mixed gas–water system under different conditions. Results indicate that convection dominates the heat transfer at the gas–liquid interface. Effects of gas Reynolds number, coolant inlet temperature, combustion chamber pressure, mass flow ratio of the liquid coolant to the free stream and the free stream turbulence on the liquid film length are presented in detail.     

Electrochemical model for performance analysis of a tubular SOFC

Tubular solid oxide fuel cells (SOFC) are promising candidates for future energy conversion systems and expected to be applied widely for small‐scale distributed generation to large‐scale central station power plants because of their high electrical efficiency and high temperature exhaust gas utilization. This study presents an electrochemical model to determine the performance characteristics of tubular solid oxide fuel cell. Activation, ohmic and concentration polarizations are regarded as the major sources of irreversibility. The Butler–Volmer equation, Fick's law and Ohm's law are used to determine the polarization terms. Performance curves are simulated for single cell voltage and power under variable current density and validated with published experimental data for given operating conditions. All the variations of tubular SOFC's operational conditions such as operating pressure and temperature in the electrochemical processes is taken into consideration. The contribution of each polarization term to voltage losses is analysed with local characteristics such as pore size, electrolyte thickness and activation energy for evaluating the relative changes. Cell performance represented by cell voltage, power, efficiency and heat generation are analysed at its complete operating range, aiming at finding the set of optimal operating conditions maximizing the overall cell performance. As a conclusion from this study, the developed model is a simple and effective tool to analyse tubular SOFC in obtaining insight information about cell performance characteristics under different conditions. Copyright © 2006 John Wiley & Sons, Ltd.     

Hybrid model of steam boiler

In the case of big energy boilers energy efficiency is usually determined with the application of the indirect method. Flue gas losses and unburnt combustible losses have a significant influence on the boiler's efficiency. To estimate these losses the knowledge of the operating parameters influence on the flue gases temperature and the content of combustible particles in the solid combustion products is necessary. A hybrid model of a boiler developed with the application of both analytical modelling and artificial intelligence is described. The analytical part of the model includes the balance equations. The empirical models express the dependence of the flue gas temperature and the mass fraction of the unburnt combustibles in solid combustion products on the operating parameters of a boiler. The empirical models have been worked out by means of neural and regression modelling.     

Energy and exergy analysis of Solid Oxide Electrolyser Cell (SOEC) working as a CO2 mitigation device

A simple thermodynamic model of SOEC system was presented in this paper. We performed energy and exergy analysis on the SOEC system to determine its optimal operating conditions. Parametric studies have been carried out to determine the effects of key operating parameters on the SOEC system. For given operating conditions and set assumptions, it was found that the optimal voltage applied to the SOEC system is 1.37 V. At this optimal value, the SOEC system is capable of achieving 50% and 60%, respectively, in terms of energy and exergy efficiency. It also achieved 67% reduction in CO₂ with maximum feedstock conversion of 63.5%. The corresponding energy and exergy required to convert one kg of CO₂ is 16.4 kJ and 7.2 kJ, respectively.     

燃气轮机燃烧室柔和燃烧热力学与燃料条件的计算分析

本文通过零维数值模拟,对基于烟气循环的不同级别燃气轮机燃烧室中实现柔和燃烧的条件进行了计算分析。结果表明燃气轮机燃烧室柔和燃烧主要受回流烟气和燃料、空气的混合物温度的影响,烟气回流起到缩短混合物点火延迟时间的作用。由于不同燃料和不同负荷条件下混合物自燃温度变化不大,柔和燃烧具有较好的燃料适应性和变负荷性能。分析还表明未完全反应的烟气不会影响柔和燃烧工况范围。