【作者】 马正中；

【导师】 肖云汉； 徐祥；

【作者基本信息】 中国科学院研究生院（工程热物理研究所） ， 热能工程， 2012， 博士

【摘要】 滴管炉是研究煤等含碳固体燃料反应过程的重要动力学实验装置。研发加压滴管炉进行高温、高压、高升温速率的气化反应动力学研究,已成为滴管炉发展的趋势。本文在分析现有国内外滴管炉的基础上,研究并建成了加压滴管炉,进行了单一操作参数对典型煤种热反应特性的影响规律实验。主要研究内容和结果包括：(1)研制了常压微量给料器和加压微量给料器。给料器采用了无轴螺旋输送方式,加压条件下给料速率在0.4-1.0g/min范围时的给料精度为士7.2%,稳定性较好。给料速率仅与搅拌螺旋转速、输送螺旋转速有关,而与料位、载气流量以及操作压力无关。给料量与给料时间、给料速率与输送螺旋转速之间均具有良好的线性关系。(2)研制了加压滴管炉及其预热器。炉顶入口处的刚玉支撑件上设计有孔道,解决了反应管内外压力平衡问题；纤维衬里的孔隙率和耐压强度测试验证了该材料在高压操作时的可行性和可靠性；硅碳棒的“井”字型水平布置和多区控温方式,改善了反应区温度的均匀性；设计的四氟套组件解决了硅碳棒在加压时的密封问题；进样枪长度可调节的方案经济方便地实现了加压时的连续取样；加压预热器结合了加压滴管炉与填充床的结构设计方案。此外,计算得出了硅碳棒、进样枪、取样枪以及预热器的具体设计参数。(3)完成加压滴管炉的集成及调试；提出了可控制颗粒反应行为的给料速率的操作准则；获得了反应区温度的实际分布和控制精度；计算了颗粒的温度和升温速率；研发了平台数据监控系统,并分析了实验误差。(4)进行了典型煤种在高升温速率条件下的热解和气化试验,在热解实验中采用了灰示踪法,实现了对煤粉颗粒的温度(升温速率)和停留时间的单独控制和调节；在气化实验中采用了氮示踪法和色谱分析,实现了对煤粉颗粒的温度(升温速率)、停留时间、氧煤比和压力的单独控制和调节,得到了两种煤转化率随上述单一操作参数变化的反应特性。实验结果符合反应的基本规律和已有的滴管炉实验结果,验证了本文研制的加压滴管炉可靠性。更多还原

【Abstract】 The drop tube furnace (DTF) is one of the important experiment devices used in coal reaction process research, and the development of pressurized drop tube furnace (PDTF) used for coal dynamics research at high temperature, high pressure, and high heating rate conditions is the trend of DTF. In this paper, on the basis of analysis of the DTF home and abroad, the PDTF had been investigated and established, and then thermal reaction characteristics of typical coal under independent operation parameter were investigated with PDTF.The main research contents and results are summarized as follows:(1) Two microfeeders working in atmospheric and pressurized conditions were established individually. The microfeeder adopted shaftless screw mode and showed good stability with precision is±7.2%when feeding rate is0.4-1.0g/min at pressurized conditions. The feeding rate of microfeeder depends on the speed of agitating screw and conveying screw, and is independent of flow rate of carrier gas, stack height of paticles and operating pressure.(2) The pressurized drop tube furnace was investigated and established. The pressure keeps balance between inside and outside the reaction tube by pipe design of corundum fixed components on the furnace top. The feasibility and reliability of fiber lining under pressurized conditions were proved by porosity and compressive strength tests. Horizontal staggered arrangement and multiple zone tempreture control of SiC heaters improved temperature uniformity of the reaction zone. Designed ePTFE components seal SiC heaters under pressurized conditions. A series of length-adjustable injection probes realize economically and conveniently continuous sampling under pressurized conditions. The structure design of pressurized preheater has characteristics of both PDTF and packed beds. In addition, the specific design parameters of SiC heaters, injection probe, collection probe and preheater were calculated. (3) The Integration and commissioning of PDTF system were performed. The feeding rate operation criterion of controlled particle reaction behavior was proposed. According to actual temperature distribution of reaction zone, the control accuracy was obtained. Moreover, temperature and heating rate of particles under different conditions was calculated. Data monitoring system was developed and experiment error was analyzed.(4) The pyrolysis and gasification experiment of typical coals with high heating rate were studied. Ash tracer method has been developed in pyrolysis experiment, and the reaction conditions of pulverized coal was controlled and adjusted individually with temperature (heating rate) and residence time. Nitrogen tracer method and chromatographic analysis has been developed in gasification experiment, and the reaction conditions of pulverized coal was controlled and adjusted individually with temperature (heating rate), residence time, O2/Coal and pressure. The results of experiment showed conversion of typical coals changed with individual operation parameters and were accord with reaction basic rules and existing experimental results of DTF and verified reliability of PDFT established in this paper.更多还原