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分光光度法测定工业水中的酚酞碱度 总被引:1,自引:0,他引:1
建立了分光光度法测定工业及锅炉用水中酚酞碱度的分析方法。以间硝基苯酚为显色剂,采用分光光度法,测定了吸光度与酚酞碱度之间的线性关系。对测定波长、显色剂用量、显色时间等条件进行优化选择,考察了该方法的准确度和精密度。方法检出限为0.004 5 mmol/L,测定结果的相对标准偏差为0.20%~0.70%(n=9),加标回收率为97.0%~99.0%。该方法检出限低,精密度高,受样品颜色,浑浊度等的影响小,适合工业及锅炉用水酚酞碱度的测定,尤其适用于低酚酞碱度水样。 相似文献
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1前言 四角喷燃的煤粉锅炉是目前我国大型发电锅炉最主要的炉型,为保证其动力工况的可靠性,合理地布置受热面和选择受热面材料,有效组织炉膛内的燃烧过程以提高锅炉运行的安全性,锅炉设计人员需要准确地预报锅炉炉膛内,特别是燃烧器区及炉膛出口区的烟气温度分布等参数. 相似文献
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四角切圆炉膛三维温度分布优化控制建模研究 总被引:2,自引:0,他引:2
炉膛燃烧三维温度分布可视化技术为实现炉内燃烧三维温度分布优化控制奠定了基础。本文采用数值计算的方法建立了炉内不同高度特征截面平均温度及相应的温度中心坐标作为中间被控变量,以各层各角燃烧器燃料量及一次风、二次风量等参数为输入变量的线性模型。检验结果表明该模型能正确反映输入变量的变化对炉内温度分布的影响,为采用自适应遗传算法实施燃烧优化控制创造了条件。 相似文献
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Wojciech P. Adamczyk ;Gabriel Wecel ;Marcin Klajny ;Pawet Kozolub ;Adam Klimanek ;Ryszard A. Biatecki 《Particuology》2014,(5):29-40
The constantly developing fiuidized combustion technology has become competitive with a conventional pulverized coal (PC) combustion. Circulating fluidized bed (CFB) boilers can be a good alternative to PC boilers due to their robustness and lower sensitivity to the fuel quality. However, appropriate engineering tools that can be used to model and optimize the construction and operating parameters of a CFB boiler still require development. This paper presents the application of a relatively novel hybrid Euler-Lagrange approach to model the dense gas-solid flow combined with a combustion process in a large-scale indus- trial CFB boiler. In this work, this complex flow has been resolved by applying the ANSYS FLUENT 14.0 commercial computational fluid dynamics (CFD) code. To accurately resolve the multiphase flow, the original CFD code has been extended by additional user-defined functions. These functions were used to control the boiler mass load, particle recirculation process (simplified boiler geometry), and interphase hydrodynamic properties. This work was split into two parts. In the first part, which is referred to as pseudo combustion, the combustion process was not directly simulated. Instead, the effect of the chemi- cal reactions was simulated by modifying the density of the continuous phase so that it corresponded to the mean temperature and composition of the flue gases, In this stage, the particle transport was simu- lated using the standard Euler-Euler and novel hybrid Euler-Lagrange approaches, The obtained results were compared against measured data, and both models were compared to each other. In the second part, the numerical model was enhanced by including the chemistry and physics of combustion. To the best of the authors' knowledge, the use of the hybrid Euler-Lagrange approach to model combustion is a new engineering application of this model, In this work, the combustion process was modeled for air-fuel combustion. The simulation results were compared with experimental data. 相似文献
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While circulating fluidized bed (CFB) reactor has many advantages over the more conventional turbulent fluidized bed (TFB) reactor, it does at least have one significant shortcoming-the rather dilute solids volume concentration in CFB reactor gives rise to less ideal reaction intensity. On the other hand, while having higher reaction intensity, TFB reactor has one fatal drawback of particle back-mixing, making it not suitable for certain reactions such as catalytic reaction where the catalyst requires frequent regeneration. This paper describes some key issues in the development of a circulating turbulent fluidized bed (CTFB) reactor that combines the advantages of both TFB and CFB, that is, to have the high reaction intensity as in TFB but and also to have a suppressed solids back-mixing as in CFB due to a continuous net upflow of solids flux through the bed. Experimental results show enough evidence to suggest that a new fluidization regime is formed, the characteristics of which appears to be distinct from those observed in a regular TFB and from those in either the bottom or the upper sections of regular CFB and/or high-density CFB (HDCFB). Fundamentally, the difference is that particle-particle interaction (collision) dominates the motion of particles in CTFB and TFB, while gas-particle interaction (drag force) is the key element that determines the two phase flow in CFB including HDCFB. 相似文献
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