報告書番号

W99017

タイトル（和文）

ガス化炉における石炭灰付着・成長機構の解明 -－第２報 粒子の温度、粒径、速度同時計測による灰付着挙動の解析－-

タイトル（英文）

Study on the mechanism of the coal ash deposit and the growth in the gasifier－ Part 2. Analysis of Ash Adhesion Tendencies by Simultaneous Measurement of Temperature, size and velocity on a particle by particle basis －

概要 （図表や脚注は「報告書全文」に掲載しております）

石炭ガス化炉では、石炭中灰分が炉内壁面へ付着・成長する現象が見られ、炉の運転に支障を来すことがある。ガス化炉運転の信頼性確保のためには、炭種や運転条件に対し、炉内灰付着性を十分に評価する必要がある。しかしながら、従来の灰付着性指標は、溶融灰の粘性をもとに判断するものがほとんどであり、ガス化炉内の灰軟化点前後のガス温度領域において、部分溶融粒子の付着性を十分予測できるものとなっていない。本研究では、石炭ガス化炉壁を模擬したテストプローブへの灰粒子付着性評価試験を実施し、衝突粒子の粒径、速度、温度を高速度ビデオカメラにより同時計測を行う。灰付着挙動と粒子状態量との相関性について検討を行うとともに、付着機構について考察する。

概要 （英文）

For the entrained flow coal gasifier, most of coal ash are separated from the product gas and discharged as molten slag. However, some ash particles carried with the product gas can adhere on the inner wall of the gasifier or downstream. Sometimes, they may make disturbance to operation. Generally, the entrained flow coal gasifier has a higher gas temperature area which is above ash fusion point in order to discharge the ash as the molten slag. And it is decreasing suddenly by gasification reaction and it comes to be below the ash softening point in the exit of the gasifier. This study focuses on the relationship between the ash particles sticking tendencies and particle temperature, size and velocity during impacting. Ash deposition tests were conducted using the drop tube furnace and in-flight measurement of particle properties was conducted using the particle analyzing system. The particle analyzing system consists of high-speed video with long distance microscope and PC. This high-speed video camera has 2 reflection mirrors inside that can split the original image into 3 color images and it can record them simultaneously. Particle temperatures are calculated with 2-colors method, and particle sizes are calculated by pixel counting. Besides, velocities are calculated with particles tracking. Using this technique, the relationship between the ash particles behavior ”stick” or “rebound” and particles temperature, size and velocity during impacting were examined. Sticking probabilities were estimated.

報告者

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