共查询到18条相似文献,搜索用时 277 毫秒
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循环流化床锅炉的分离机构是循环流化床锅炉的关键部件之一,其主要作用是将大量高温、高浓度固体物料从气流中分离出来,送回燃烧室,以维持燃烧室一定的颗粒浓度,保持良好的流态化状态,保证燃料和脱硫剂在多次循环、反复燃烧和反应后使锅炉达到理想的燃烧效率和脱硫效率。因此,循环流化床锅炉分离机构的性能,将直接影响整个循环流化床锅炉的总体设计、系统布置及锅炉运行性能。 相似文献
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循环流化床烟气脱硫中物料平衡计算及试验研究 总被引:1,自引:0,他引:1
通过对干法烟气脱硫物料平衡计算,确定脱硫塔内固体颗粒物平衡浓度和达到平衡浓度所需要的时间, 并和实测值加以比较.在一台循环流化床烟气脱硫装置上,研究了固体颗粒物浓度对装置脱硫效率影响、阻力特性以及固体颗粒物循环对脱硫装置稳定运行的影响.结果表明,固体颗粒物的循环可以使脱硫效率提高10%-15%, 脱硫系统物料循环平衡的时间大约为30 min.综合实验结果,循环流化床烟气脱硫塔内固体颗粒物浓度宜控制在 600-1 000 g/m3之间. 相似文献
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保证循环流化床锅炉循环物料的成灰特性是循环流化床锅炉安全经济运行的重要条件,针对循环流化床锅炉运行中不加石灰石对锅炉运行的不利影响进行探讨,并提出了解决措施。 相似文献
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采用计算颗粒流体力学(CPFD)的方法对300 MW循环流化床锅炉内的气固两相流体动力学参数进行全床数值模拟研究,重点分析了循环流化床锅炉炉膛以及回料阀的气固流动特性,获得固相颗粒浓度和速度场在炉膛内的分布以及固体循环流量、系统压力平衡、回料阀的运行情况等锅炉关键参数。结果表明:颗粒浓度的轴向分布呈现明显的密相区和稀相区两部分,模拟得到的轴向压力分布与实际工况吻合较好,验证了CPFD方法模拟循环流化床锅炉的准确性;锅炉回料阀内压降最大,这与床料分布相符;回料阀返料室流化程度较高,而输运室流化程度较小,呈现鼓泡床状态,气泡大都贴壁逃逸。 相似文献
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循环流化床锅炉技术是目前迅速发展起来的一项高效、清洁燃烧技术。结焦就是循环流化床锅炉运行中较为常见的故障,它直接影响到锅炉的安全经济运行。结合循环流化床锅炉的运行特点,根据本人几年来的流化床锅炉调试和运行经验,分析流化床锅炉结焦的主要原因,并对如何预防循环流化床锅炉结焦进行了探讨。 相似文献
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脉冲流化床极易受操作条件的影响而表现出不同的流态化。从脉冲流化床的气固两相(脉冲气流和固体颗粒)的物理属性入手,综述能影响脉冲流化床气固流动特性的相关因素、影响机理及如何调整这些因素以得到较高的流化质量;展望该领域需进一步研究的问题。 相似文献
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《International Communications in Heat and Mass Transfer》1999,26(4):499-508
Heat Transfer from the wall of a circulating fluidized bed to the fast bed suspension has been investigated for several materials. The range of investigation includes dense and dilute phase fast fluidization and pneumatic transport. The overall heat transfer coefficient was found to be a function mainly of cross-sectional average suspension density. Effects of superficial velocity and solids mass flux were obscured by their interrelationship to the suspension density. Two models from the literature are evaluated using present and published data. 相似文献
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The aim of this paper is to increase the understanding of the role of the binary circulating fluidized bed in the process of clean and ecological coal combustion. The operating range of a stable fluidized bed, as a function of gas velocity changes and the flow rate of fine particles, is determined for all possible conditions. Experiments concerning the combustion and desulfurization processes in multi-solid fluidized bed (MSFB) and circulating fluidized bed (CFB) systems give evidence that the residence time of burnt particles in the combustion chamber of MSFB is much extended. This is directly reflected in better combustion conditions, especially those for fine particles, as well as in the process of desulfurization. The advantages of the binary circulating fluidized bed over typical circulating systems make it one of the most efficient methods of clean and ecological coal combustion. 相似文献
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利用循环流化床内气-固两相流动等基础方面的研究成果,根据本文床内气固浓-淡流动模型,建立适用不同结构参数的循环流化床燃烧模型,考虑了床内气体、固体颗粒的返混、循环过程,以及煤燃烧、NO的生成和分解、颗粒磨损等因素。在循环流化床燃烧试验台上进行实验研究,模型仿真结果和实验数据吻合良好,表明气固两相浓-淡流动模型所建立的循环流化床燃烧系统模型可以正确地模拟循环流化床的燃烧过程。 相似文献
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A.V.S.S.K.S. GuptaP.K. Nag 《International Journal of Heat and Mass Transfer》2002,45(16):3429-3436
An experimental investigation has been made to study the effect of pressure and other relevant operating parameters on bed hydrodynamics and bed-to-wall heat transfer in a pressurized circulating fluidized bed (PCFB) riser column of 37.5 mm internal diameter and 1940 mm height. The experiments have been conducted with and without bed material for the consideration of frictional pressure drop due to gas density at elevated pressures. The pressure drop measured without sand particles is assumed as the pressure drop due to gas density for the calculation of bed voidage and suspension density profiles. The specially designed heat transfer probe is used to measure the bed-to-wall heat transfer coefficient. The experimental results have been compared with the published literature and good agreement has been observed. The axial bed voidage is less in the bottom zone of the riser column and is increasing along the height of the bed. With the increase in system pressure, the bed voidage is found to be increasing in the bottom zone and decreasing in the top zone. The heat transfer coefficient increases with the increase in system pressure as well as with the gas superficial velocity. The heat transfer coefficient is also observed to be increasing with the increase in average suspension density. 相似文献