Abstract This paper investigates the time and space dependent dynamics of the movement and heat transfer of the bed inside the reactor during the biomass gasification process in a downdraft system. Measurement technology that uses radiographic methods is proposed and described. In general, the rate of bed subsidence decreases with time. However, the bed movement is highly diversified in the air nozzle area. In this region, the mean velocity of the bed is slightly faster than at the beginning of the process due to high temperatures and intensive oxidation in the burning zone. Unexpectedly, the radiographic markers (representing the motion of fuel particles) can be visibly separated into two groups: the center region group and the wall region group. This is likely to be the effect of limited air coverage in the center region of the gasifier. The velocity difference of the two groups amounted to 10:1 at the air nozzle level, with the wall region group being faster. Determination of particle velocity combined with temperature measurements allows us to estimate the heating rate in the gasifying system work conditions. The actual heating rate for the investigated installation was roughly estimated to be 130 °C/min in the wall region of the gasifier.

中文翻译：

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下吸式气化炉中生物质颗粒的运动和传热动力学 - 使用射线照相方法的实验测量

摘要 本文研究了在下吸式系统中生物质气化过程中反应器内床层运动和传热的时空相关动力学。提出并描述了使用射线照相方法的测量技术。一般来说，地床下沉的速度随着时间的推移而降低。然而，空气喷嘴区域的床运动高度多样化。在该区域，由于燃烧区的高温和强烈氧化，床的平均速度比过程开始时略快。出乎意料的是，射线照相标记（代表燃料颗粒的运动）可以明显地分为两组：中心区域组和壁区域组。这很可能是气化炉中心区域空气覆盖有限的影响。两组的速度差异在空气喷嘴水平达到 10:1，壁区组速度更快。结合温度测量确定粒子速度使我们能够估计气化系统工作条件下的加热速率。所调查装置的实际加热速率在气化炉壁区域粗略估计为 130 °C/min。