循环流化床高灰油页岩半焦燃烧特性的实验研究
发布时间：2018-11-11 08:08
【摘要】：油页岩是最具开发潜力的非常规油气资源,其主要利用形式是通过干馏制备页岩油。在干馏过程中,会产生大量的固体废弃物——油页岩半焦,因其灰分含量高、热值低,难以利用,目前直接填埋处理的方式不仅影响生态环境还造成了资源的浪费。由于循环流化床燃烧技术能够使用高灰分、低热值的劣质燃料,所以,针对油页岩半焦利用,对其在循环流化床锅炉中的燃烧特性进行研究就具有明确的工程意义,所获结果为油页岩半焦的燃烧利用提供了较为可靠的基础数据。本文首先使用管式加热炉对三个产地的油页岩在450℃-600℃条件下干馏处理;并运用TGA/DSC 1/1600HT型热重分析仪以30℃/min的升温速率,研究了干馏温度、干馏时间和油页岩产地对油页岩半焦的成分、发热量和燃烧性能的影响;计算了各个样品的燃烧特性指数和动力学参数;此外,在截面为1m×1m,高度为22.5m的3.3MWth循环流化床中试装置上进行了油页岩与半焦的混燃试验,获得了工业应用中油页岩半焦与油页岩的混燃特性,探索了运行中燃烧效率和污染物排放特征。研究结果表明,对于吉林桦甸和山东龙口油页岩,干馏使得其发热量降低一半,但对于黑龙江依兰油页岩并没有太大影响,这主要与固定碳含量有关。从着火温度Ti、燃尽温度Th、可燃特性指数SW等多个燃烧特性指数判断,黑龙江依兰油页岩和半焦的燃烧特性最好。热重燃烧试验发现,因固定碳含量不同,吉林桦甸和山东龙口的油页岩和半焦样品燃烧有明显的三个阶段:350℃-500℃间挥发分析出燃烧阶段、500℃-700℃间固定碳燃烧阶段和700℃之后的矿物质分解阶段;而黑龙江依兰油页岩则表现出较为连续的失重现象。通过对比Friedman-Carroll法、Coats-Redlfern法和直接Arrhenius法,确定了使用直接Arrhenius法计算油页岩半焦燃烧的动力学参数更加合理。干馏时间和干馏温度增加后,半焦的燃烧特性变差、挥发分燃烧的活化能增加,而且干馏温度的影响要大于干馏时间。在循环流化床中试装置上的研究结果指出,利用煤燃料将锅炉运行至炉膛温度分布均匀、压力分布合理的稳定状态后,先后加入纯油页岩和油页岩与半焦配比分别为3:1与2:1的混合燃料。运行结果表明在油页岩和半焦比例为2:1的工况下锅炉仍然可以较为平稳运行,自脱硫效率达到了69.9%,同时氮氧化物原始排放值可以控制在150mg/m3以下,但是由于半焦较差的成灰磨耗特性,炉膛内的压力和温度分布变差,半焦的高灰分不利于燃尽,底渣和飞灰中的含碳量较高。
[Abstract]:Oil shale is the most potential unconventional oil and gas resource. In the process of dry distillation, a large number of solid waste, oil shale semi-coke, is produced. Because of its high ash content and low calorific value, it is difficult to use. At present, the way of direct landfill treatment not only affects the ecological environment but also causes the waste of resources. Because circulating fluidized bed combustion technology can use inferior fuel with high ash content and low calorific value, it is of engineering significance to study combustion characteristics of oil shale semi-coke in circulating fluidized bed boiler. The results provide reliable basic data for combustion and utilization of oil shale semi-coke. In this paper, firstly, the oil shale from three producing areas was treated by dry distillation at 450 鈩，
本文编号：2324268
[Abstract]:Oil shale is the most potential unconventional oil and gas resource. In the process of dry distillation, a large number of solid waste, oil shale semi-coke, is produced. Because of its high ash content and low calorific value, it is difficult to use. At present, the way of direct landfill treatment not only affects the ecological environment but also causes the waste of resources. Because circulating fluidized bed combustion technology can use inferior fuel with high ash content and low calorific value, it is of engineering significance to study combustion characteristics of oil shale semi-coke in circulating fluidized bed boiler. The results provide reliable basic data for combustion and utilization of oil shale semi-coke. In this paper, firstly, the oil shale from three producing areas was treated by dry distillation at 450 鈩，
本文编号：2324268
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