Coal‐water fuels have been actively studied in the last decade due to the fact that when they are burned in the furnaces of steam and hot‐water boilers, much less anthropogenic oxides of sulfur, nitrogen, and carbon are formed in comparison with coal. The main problem that hinders the widespread introduction of such fuels in the energy sector is long (up to 30 seconds) ignition delay times. Significant (10%‐50%) reduction in the ignition delay time is possible when a small (up to 10%) amount of available and inexpensive liquid combustible organic compounds are added to the suspension. The purpose of the work is to substantiate (from the results of experimental studies) the possibility of significant reduction of the ignition delay times of coal‐water fuels by introducing a third component into the suspension—isopropyl alcohol in relatively small (from 3% to 8%) concentrations. According to the results of experimental studies on the ignition process of multicomponent coal‐water fuel droplets, based on long‐flame coal, with addition of isopropyl alcohol in oxidizer (still air) heated to high temperatures (from 873 to 1273 K), with recording the processes of heating, ignition, and combustion by a high‐speed video camera (speed of shooting up to 10⁵ frames per second), the mechanism, characteristics, and conditions of ignition of the researched compositions of quite promising fuels were established. Experiments have shown that the delay time of stable ignition of the studied suspensions based on long‐flame coal decreases by 12% to 47% with the increase (from 3% to 8%) of the mass concentration of isopropyl alcohol in the composition of coal‐water fuel at the initial characteristic size of droplets from 1.5 to 3.5 mm. Each studied composition was compared with conventional coal‐water fuel burned under similar conditions. The influence of mass concentration of isopropyl alcohol in the composition of the coal‐water fuel on the characteristics of the initiation of ignition and combustion processes, established in the experiments, proves the possibility of effective an application of such three‐component suspensions in thermal power engineering. The possibility of formation of a significantly larger quantity (about 80%) of small droplets (250‐400 μm) in the flow during atomization of coal‐water fuel with addition of isopropyl alcohol in comparison with the usual coal‐water suspension was experimentally proved. The results are of significant practical importance because they illustrate the possibility of achieving optimum conditions for ignition and combustion of promising multi‐component coal‐water slurries with the addition of alcohol in the furnaces of boiler plants of large‐ and small‐scale power engineering.

中文翻译：

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加入异丙醇点燃水煤油滴

在过去的十年中，人们对水煤燃料进行了积极的研究，因为与蒸汽相比，当它们在蒸汽和热水锅炉的炉中燃烧时，形成的硫，氮和碳的人为氧化物要少得多。阻碍这种燃料在能源领域广泛应用的主要问题是点火延迟时间长（长达30秒）。当向悬浮液中添加少量（最高10％）的可用且廉价的液体可燃有机化合物时，可以大大减少（10％-50％）点火延迟时间。这项工作的目的是（通过实验研究的结果）证实将悬浮液中引入第三种成分-异丙醇的比例相对较小（从3％降低到3％），从而显着减少水煤燃料着火延迟时间的可能性。 8％）浓度。根据基于长焰煤的多组分煤-水燃料液滴点火过程的实验研究结果，在加热至高温（873至1273 K）的氧化剂（静止空气）中添加异丙醇，通过高速摄像机记录加热，点火和燃烧的过程（拍摄速度最高为10⁵每秒帧数），建立了很有前途的燃料的研究组成的机理，特征和着火条件。实验表明，随着煤中异丙醇质量浓度的增加（从3％到8％），基于长焰煤的悬浮液稳定点火的延迟时间减少了12％至47％。 -水滴初始特征尺寸为1.5至3.5 mm的水燃料。将每个研究的成分与在类似条件下燃烧的常规煤水燃料进行了比较。实验确定的煤水燃料成分中异丙醇的质量浓度对着火和燃烧过程启动特性的影响，证明了将这种三组分悬浮液有效地应用于火电工程的可能性。通过实验证明，与常规的煤水悬浮液相比，在添加异丙醇的煤水燃料雾化过程中，在水流中会形成大量（约80％）小液滴（250-400μm）的可能性。 。该结果具有重要的现实意义，因为它们说明了在大型和小型电力工程锅炉工厂的熔炉中添加酒精后，有可能实现有希望的多组分水煤浆点火和燃烧的最佳条件的可能性。通过实验证明，与常规的煤水悬浮液相比，在添加异丙醇的煤水燃料雾化过程中，在水流中会形成大量（约80％）小液滴（250-400μm）的可能性。 。该结果具有重要的现实意义，因为它们说明了在大型和小型电力工程锅炉工厂的熔炉中添加酒精后，有可能实现有希望的多组分水煤浆点火和燃烧的最佳条件的可能性。通过实验证明，与常规的煤水悬浮液相比，在添加异丙醇的煤水燃料雾化过程中，在水流中会形成大量（约80％）小液滴（250-400μm）的可能性。 。该结果具有重要的现实意义，因为它们说明了在大型和小型电力工程锅炉工厂的熔炉中添加酒精后，有可能实现有希望的多组分水煤浆点火和燃烧的最佳条件的可能性。