水煤浆水冷壁废锅气化过程的模拟研究

采用Aspen Plus流程模拟软件模拟了水煤浆水冷壁废锅气化过程,并将模拟结果与工业运行数据对比,验证了模型准确性。在此基础上,分析了气化压力和水煤浆浓度对气化温度、有效气产量、合成气组成、氧煤比、比氧耗和比煤耗等气化参数的影响。结果表明,气化压力对气化过程基本没有影响,可根据需要选择适宜压力;当保持氧气流量恒定时,随水煤浆浓度增大,有效气含量增加,气化温度升高,即提高水煤浆浓度易导致气化炉飞温,因此进一步研究了在前述模拟条件不变,且保持气化温度恒定时,水煤浆浓度变化对气化参数的影响。结果表明,随水煤浆浓度增大,氧煤比降低,有效气含量增加,比氧耗、比煤耗降低,因此在气化炉不超温的情况下,应尽量提高水煤浆的浓度,以降低系统能耗。     

运用Gibbs自由能最小化方法模拟气流床煤气化炉

基于 Aspen Plus工业系统流程模拟软件 ,运用 Gibbs自由能最小化方法建立了气流床煤气化炉的模型 .研究了气化炉的主要操作参数 (即水煤浆浓度、氧煤比、碳转化率和气化温度 )对气化结果的影响 .对模拟结果进行了分析 ,发现模型基本正确 ,可应用于一些反应机理复杂的气化工艺的化学和热力学平衡计算 .模拟结果表明 ,氧煤比和水煤浆浓度是影响气化炉出口煤气组成的主要因素 ,气化炉温度随着氧煤比的增加而增加 ,也随着水煤浆浓度的增加而增加 .结果还表明 ,氧煤比对气化结果的影响比水煤浆浓度的影响更为显著     

基于Aspen Plus的多元料浆气化工艺模拟与分析

以延安能化气化装置为研究对象,利用Aspen Plus流程模拟软件,建立水煤浆气化过程的平衡模型,分别考察了水煤浆浓度、氧煤比、气化压力三个关键控制参数对气化结果的影响。结果表明:在气化炉可以承受的温度范围内应尽量提高水煤浆浓度;有效气(CO+H_2)含量随氧煤比的增大先增加后减小;气化压力对气化结果基本无影响;控制水煤浆浓度60%～64%、氧煤比0.95左右,能实现较大的经济效益。     

同向多轴水煤浆气化数值模拟研究

为弥补现有水煤浆气流床气化技术的不足,研发了一种同向多轴煤气化装置,采用Aspen Plus建立了同向多轴水煤浆气化数值模拟模型,分析了水煤浆浓度、氧煤比和碳转化率对煤气化效果的影响。结果表明,随着氧煤比的增加,H_2、CO、有效气含量均先增大后降低,气化温度逐渐升高,最佳氧煤比为0.61,此时有效气含量最大。随碳转化率的升高,CO和H_2含量均增大,气化温度逐渐降低,对于气化炉而言,提高碳转化率可增加有效气含量。水煤浆浓度分别为60%、62%和65%时,有效气(干基)含量分别为81.3%、82.5%和84.2%,水煤浆浓度每提高1%,有效气含量增加约0.6%。     

水煤浆气化工艺过程的模拟研究与分析

以河南某煤种为反应原料,采用Aspen Plus流程模拟软件对水煤浆气化工艺过程进行了流程模拟,考察分析了气化炉内的氧煤比和煤浆浓度等原料条件以及气化温度和压力等操作条件对气化反应结果的影响,并将模拟结果与实验结果进行比较,结果表明：模型基本正确,在误差许可范围内,模拟结果与气化实验结果基本一致;氧煤比、水煤浆浓度和气化温度是影响气化反应结果的主要因素;气化压力则对煤气化反应结果几乎没有影响,但是加压气化有利于降低后续工段合成气压缩能耗。     

气化炉工艺烧嘴的运行监控及管理

水煤浆气化工艺属气流床气化工艺。其原理是将水煤浆与气化剂(纯氧)通过装在气化炉顶的特殊设备——工艺烧嘴(通过氧流股与煤浆流股的动量交换),达到雾化煤浆的目标,为炉内的气化与燃烧过程创造条件,煤浆喷入高温气化炉内进行快速气化反应得到产物煤气。烧嘴     

水煤浆气化有效气含量的影响因素

通过对气化炉运行参数比较,研究了水煤浆气化有效气含量的影响因素,分析了原料煤质量、水煤浆浓度、气化氧煤比以及烧嘴雾化效果对水煤浆气化有效气含量的影响。结果表明:高质量原料煤、高浓度水煤浆、合适的氧煤比以及较佳雾化效果的烧嘴均能提高有效气含量。同时,操作条件调控还受到生产安全条件制约。因此,需要综合考虑多方面因素的影响,尽可能在安全的前提下提高水煤浆气化有效气含量,提高经济效益。     

水煤浆气化掺用石油焦运行的实践及问题分析

为实现生产控煤任务,进行了水煤浆气化装置的掺焦运行实践。研究了石油焦掺加比例对煤浆性能的影响,实验结果及生产运行表明,掺加石油焦后,煤浆浓度提高,黏度降低。针对生产中掺加石油焦后水煤浆气化炉、渣水系统、脱硫系统存在的问题进行了原因分析,并采取了相应的工艺调整和优化措施,实践表明,水煤浆气化装置掺加石油焦运行,在完成控煤任务的同时,保证了装置长周期稳定运行的效果。     

基于平衡模型的煤气化过程模拟分析

选用典型煤种对平衡模型进行了模拟验证,通过对比模拟计算结果与试验数据,证明了本文所建立的水煤浆气化平衡模型的可信度。同时利用该平衡模型模拟分析了水煤浆浓度、氧煤比、氧气纯度等参数对气化过程的影响,结果表明采用合理制浆工艺尽可能提高水煤浆浓度,尽可能提高氧气纯度,氧煤比不宜调节过高,这些措施能够提高合成气产量及气化炉热效率。     

水煤浆制备的影响因素分析

气化炉将水煤浆作为原料进行气流床两相并流反应,在反应过程中的气炉运行稳定性受多重因素的影响,其中重要的影响因素之一为制浆工艺。通过对中气化水煤浆的制备过程中的相关问题进行分析总结,探究对气化炉的产气量、耗氧、电耗及气体成分等有决定性的煤浆质量,主要对水煤浆制备过程中的关键影响因素进行了分析。     

Effects of burner type on a bench-scale entrained flow gasifier and conceptual modeling of the system with Aspen Plus

The integrated gasification combined cycle (IGCC) system is well known for its high efficiency compared with that of other coal fueled power generating systems. In this study, gasification using different types of burners with different oxygen supply angles in a bench-scale entrained flow gasifier was investigated. The effects of the oxygen gas supply angle of the coal burner and resulting oxygen supply location in the gasifier on the syngas composition and temperature of the gasifier were experimentally examined. These changes had a significant influence on the syngas composition of the final stream, carbon conversion, and efficiencies. According to the experimental results, the models using the Aspen Plus process simulator were positioned to define the effects of the experimental parameters and to find the optimum operating conditions in the bench gasifier facility.     

干法进料气流床煤气化技术的现状与发展

煤气化按煤的粒度和气化炉内的气体流速等可分为固定床、流化床、气流床3种。其中干煤粉气流床加压气化具有易大规模化、煤种适应范围广、碳转化率高等特点,近年来得到大规模的应用。详细介绍了以干煤粉为原料的Shell、Prenflo、Simens GSP和西安热工院的两段式气化技术。     

气化工艺特性对IGCC效率的影响

影响煤气化联合循环总效率的五个主要因素为煤转化率、燃气轮机循环,蒸汽循环,热旁路比率和发电效率。其中以煤转化率影响最大,它将包括产品气的显热和剩余蒸汽。在任何气化装置中气化炉是最主要单元并极大地影响气化性能。为改善气化效率,所有第二代气化方法均已引入加压操作。本文讨论了高温操作、生严能力放大、负荷跟踪能力、加煤方式、气化剂和煤气净化,同时提出仍待开发的某些值得注意的问题。     

基于IGCC机组气化炉氧气切断阀控制可靠性探究

IGCC机组气化炉氧气切断阀是气化炉氧气燃料供给控制阀,是气化炉单点跳车联锁,为保证设备安全运行,当设备出现异常或阀门控制设备故障时阀门快关。与此同时易造成由于控制设备异常造成阀门误动,引起气化炉停车甚至IGCC机组非停。讨论如何最优、最经济的对气化炉氧气切断阀控制设备的优化,以防止误动引起非停。并经过最终优化改造方案实施后达到了预期目的。     

Design of an indirect heat rotary kiln gasifier

A non-ordinary type of solid fuel gasification reactor, which was under development for the few past decades and it is briefly described as indirect heat rotary kiln gasifier, seems to be capable of sufficiently satisfying the incorporated gasification needs in the most challenging contemporary power technologies using solid fuels, like IGCC and CLC combustion. The design of such a gasifier emerges in this work, while the focus is mostly on the presentation of the relevant theoretical model. Moreover, model predictions are compared and optimized with respect to experimental data that were acquired in a pilot scale gasification unit including the suggested type of gasifier. Comparisons showed successful predictions of such a marginal error that could be characterized as quite sufficient for a primary model validation. However, the model flexibility to a wide variety of different solid fuels, rotary kiln configurations and operating conditions has to be verified by assessment of further experimental results.     

Dynamic modeling and simulation of shell gasifier in IGCC

A dynamic model of the Shell gasifier in an integrated coal gasification combined cycle (IGCC) is established based on physical principles, focusing on the time-dependent accumulation and flow on the walls. Numerical simulations are carried out to explore the system dynamic performance with respect to step changes in the inlet oxygen-to-coal ratio and steam-to-coal. The dynamic responses of key outlet variables, including the gas temperature, exiting slag mass flow rate, thicknesses of the solid and fluid slag layer, volume percentages of H₂, CO₂ and CO in syngas etc., are obtained. Three different coals are analyzed in this paper, and similar trends in their dynamic behaviors are found by using the gasifier model. The model and simulation method may be useful for providing insights to the operation and control of the IGCC process with respect to complex varying working conditions.     

IGCC示范工程煤气化炉的数值模拟

采用Aspen Plus流程模拟软件对某拟建的IGCC示范工程的德士古煤气化炉进行数值模拟,通过考虑碳的不完全转换对计算流程进行了改进,并运用CPD模型预测煤热裂解的产物分布.研究了煤气化炉的重要操作参数(即水煤浆浓度、氧煤比、气化压力和气化温度)对气化结果的影响.在计算区间内,发现高浓度水煤浆浓度范围内,随浓度的增加,煤气的主要成分(H2+CO)的总含量增加.气化温度增大到1400℃左右时,煤气的主要成分随气化温度的进一步增加会趋于一个恒定值.     

Operational characteristics of the pilot-scale coal gasification with filtration and hot fuel gas desulfurization

Experimental research on coal gasification with a filtration and desulfurization system for the development of an integrated gasification combined cycle (IGCC) was performed with Indonesian LG, KPU and Canadian Arch coals. A dry-feeding entrained-bed type gasifier was operated below the fusion temperature of the coal and at 20 bar of pressure. The filtration system was designed for continuous capture and subsequent removal of the fly ash and the unreacted coal residue via a specialty metal filter. The hot fuel gas desulfurization unit (HGD) consisted of a transport desulfurizer, a bubbling regenerator and a multi-cyclone. The research objective was to investigate the feasibility of applying a partial slagging coal gasifier to attain high carbon conversion and cold gas efficiencies as well as to attain an operational capability for combining with filtration and HGD. A Pilot-scale test demonstrated that the coal fines were effectively removed and the overall sulfur removal efficiency of the hot fuel gas desulfurization unit was higher than 95.3%.     

Experimental investigations of the effect of coal type and coal burner with different oxygen supply angles on gasification characteristics

The IGCC (Integrated gasification combined cycle) is known as one of the coal fueled power generating technologies with the highest efficiency and lowest emissions. To achieve the required higher efficiency and lower emission performance, Korea's 300 MW IGCC RDD&D (Research Development, Demonstration and Dissemination) project was launched in December 2006 under the leadership of the Korea Electric Power Corporation (KEPCO), with the support of the Korea Ministry of Knowledge Economy. Our research group, the KEPCO Research Institute, set up a coal gasifier for the pilot test and conducted many experiments for the parametric study in this project.Our group focused its research on the effect of different types of coal and oxygen supply angles on the optimum O₂/coal ratio for gasification. Through this study we found that using higher oxygen content coal reduced the optimum O₂/coal ratio for gasification. However, there was no apparent relationship between the oxygen supply angle and the optimum O₂/coal ratio. And, two types of coal burners having different oxygen supply angles were used to conduct the feasibility study on a variable angle burner for the coal gasifier.     

The comparison study on the operating condition of gasification power plant with various feedstocks

Gasification technology, which converts fossil fuels into either combustible gas or synthesis gas (syngas) for subsequent utilization, offers the potential of both clean power and chemicals. Especially, IGCC is recognized as next power generation technology which can replace conventional coal power plants in the near future. It produces not only power but also chemical energy sources such as H₂, DME and other chemicals with simultaneous reduction of CO₂. This study is focused on the determination of operating conditions for a 300 MW scale IGCC plant with various feedstocks through ASPEN plus simulator. The input materials of gasification are chosen as 4 representative cases of pulverized dry coal (Illinois#6), coal water slurry, bunker-C and naphtha. The gasifier model reflects on the reactivity among the components of syngas in the gasification process through the comparison of syngas composition from a real gasifier. For evaluating the performance of a gasification plant from developed models, simulation results were compared with a real commercial plant through approximation of relative error between real operating data and simulation results. The results were then checked for operating characteristics of each unit process such as gasification, ash removal, acid gas (CO₂, H₂S) removal and power islands. To evaluate the performance of the developed model, evaluated parameters are chosen as cold gas efficiency and carbon conversion for the gasifier, power output and efficiency of combined cycle. According to simulation results, pulverized dry coal which has 40.93% of plant net efficiency has relatively superiority over the other cases such as 33.45% of coal water slurry, 35.43% of bunker-C and 30.81% of naphtha for generating power in the range of equivalent 300 MW.