폭발 가능성에 영향을 미치는 다양한 특성을 분석하여 석탄 분진 폭발과 관련된 위험성을 조사했다. 석탄화력발전소에서 가장 많은 폭발이 발생한 이송공정의 두 지역에서 시료를 직접 채취하여 실험에 영향을 미칠 수 있는 조성비와 평균입경을 고려했다. 실험항목으로는 폭발에 영향을 미치는 폭발강도, 입자크기와 분포, 수분함량, 분진농도, 최소점화에너지, 최소점화온도, 산소농도를 평가했다. 그 결과 폭발강도는 시료 A에서 분진농도 500 g/㎥에서 최대 폭발압력이 7.1 bar, 최대 폭발압력 증가율은 366 bar/s로 나타났다. 분진 입경과 입자크기 분포에서 시료 A는 평균 직경이 35 ㎛(D 50%)로 시료 B보다 작았다. 수분함량은 시료 A에서 5.7%로 시료 B에서 2.5%보다 2배 이상 높았다. 최소 폭발농도는 시료 A에서 400 g/ ㎥로 시료 B에서 2,000 g/㎥보다 낮아 위험성을 가지고 있었다. 두 시료 모두 1,000 mJ에서 폭발하지 않았기 때문에 최소 에너지가 500 mJ 이상이면 유사한 선행연구에 비해 점화에 대한 민감도가 낮은 분진으로 간주할 수 있을 것으로 판단된다. 최소점화온도는 시료 A에서 532℃, 시료 B에서 634℃로 시료 A가 시료 B보다 더 위험했다. 한계 산소농도는 두 시료 모두 18.0%로 대기 중 폭발 위험성이 일정하게 존재하는 것으로 판단된다.

The risks associated with coal dust explosion were investigated by analyzing various characteristics affecting the possibility of explosion. Samples were collected directly from two regions of the transfer process where the most explosions occurred in coal-fired power plants, and the composition ratio and average particle diameter that could affect the experiment were considered. As experimental items, explosion intensity, particle size and distribution, moisture content, dust concentration, minimum ignition energy, minimum ignition temperature, and oxygen concentration that affect the explosion were evaluated. As a result, the explosion intensity was found to have a maximum explosion pressure of 7.1 bar at a dust concentration of 500 g/㎥ in sample A, and the maximum explosion pressure increase rate was 366 bar/s. In terms of dust particle diameter and particle size distribution, sample A had an average diameter of 35 ㎛ (D 50%), which was smaller than sample B. The moisture content was 5.7% in sample A, which was more than twice as high as 2.5% in sample B. The minimum explosion concentration was 400 g/㎥ in sample A, which was lower than 2,000 g/㎥ in sample B, so it had a risk. Since neither sample exploded at 1,000 mJ, it is judged that if the minimum energy is 500 mJ or higher, it can be regarded as dust with a low sensitivity to ignition compared to similar previous studies. The minimum ignition temperature was 532℃ in sample A and 634℃ in sample B, so sample A was more dangerous than sample B. The marginal oxygen concentration was 18.0% in both samples, so it is judged that there is a constant risk of explosion in the atmosphere.

Coal dust Characteristics analysis Dust explosion