One Question per Day (January 29, 2018)
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What does the thermal stability of coal refer to? It refers to the ability of coal samples of a certain particle size to maintain their original particle size when heated during high-temperature combustion or gasification.
What does the thermal stability of coal refer to? Answer: It refers to the ability of coal samples of a certain particle size to maintain their original particle size when heated during high-temperature combustion or gasification.
It refers to the stability of coal samples of a certain particle size in maintaining their original properties when heated during high-temperature combustion or gasification
It is the property of coal samples of a certain particle size to maintain their original size when heated during high-temperature combustion or gasification.
It refers to the stability of coal against heat during the process of vaporization through high-temperature combustion, that is, the property by which coal particles maintain their original size at high temperatures
It refers to the ability of coal samples of a certain particle size to maintain their original particle size when heated during high-temperature combustion or gasification.
Thermal stability of coal: The thermal stability of coal refers to its ability to remain stable under high-temperature combustion or gasification conditions; in other words, it is the property that allows coal particles to maintain their original size under high temperatures. Coal with good thermal stability can burn or gasify at its original particle size during the burning or gasification process, without breaking into small pieces or suffering minimal fragmentation ； Coal with poor thermal stability rapidly breaks down into small pieces or coal powder during combustion or gasification. As a result, in mild cases, slag formation inside the furnace occurs, increasing internal resistance and the amount of waste material discharged, thereby reducing the efficiency of combustion or gasification; in severe cases, it can disrupt the entire gasification process and even lead to shutdown of the furnace. Therefore, coal is required to have sufficient thermal stability. Various industrial boilers and gasifiers have different requirements regarding the particle size of coal; therefore, the methods used to determine the thermal stability of coal also vary. The two commonly used methods are as follows: (1) The method for measuring lump coal in the 13–25 millimeter range. This method involves heating the coal sample in a muffle furnace preheated to 850°C for 15 minutes, in order to determine the percentage of each sieve size relative to the total residual coke ； Curves were drawn using the cumulative percentages at various levels and the sieve sizes (1, 3, 6 mm). The percentage of residue coke larger than 13 millimeters, S+13, is used as an indicator of thermal stability, while the percentage of residue coke smaller than 1 millimeter, S-1, and the thermal stability curve are used as auxiliary indicators. (2) Method for determining lump coal of 6–13 mm size. Take 500 cubic centimeters of lump coal with a size of 6–13 millimeters, weigh it, place it in a muffle furnace preheated to 850°C and heat it for 90 minutes, then take it out, weigh it again, and sieve it. The percentages of the total weight of residues of 6 mm, mm, and <1 mm are used as stability indicators: KP6, KP3, and KP1. The higher these values, the worse the thermal stability. Classification of coal thermal stability: Grade, Thermal stability KP6, % – Good thermal stability: ≤30; Moderate thermal stability: >30–45; Poor thermal stability: >45. Most bitumens in China have good thermal stability, with KP6 values below 35%, but there are also a few types of highly metamorphosed bitumens that have poor thermal stability. Bituminous coal has poor thermal stability due to its dense structure; when heated, a large temperature difference between the inside and outside causes uneven expansion, leading to cracking. The thermal stability of bituminous coal with poor thermal stability can be significantly improved after pre-treatment.
The thermal stability of coal refers to its resistance to heat during high-temperature combustion or gasification; in other words, it is the property that allows coal particles to maintain their original size under high temperatures.
It refers to the ability of coal samples of a certain particle size to maintain their original particle size when heated during high-temperature combustion or gasification.
The thermal stability of coal refers to its resistance to heat during high-temperature combustion or gasification; in other words, it is the property that allows coal particles to maintain their original size under high temperatures. Coal with good thermal stability can burn or gasify at its original particle size during combustion or gasification, without breaking into small pieces or experiencing minimal fragmentation ； Coal with poor thermal stability rapidly breaks down into small pieces or coal powder during combustion or gasification. As a result, in mild cases, slag formation inside the furnace occurs, increasing internal resistance and the amount of material carried away, thereby reducing combustion or gasification efficiency; in severe cases, it can disrupt the entire gasification process and even lead to furnace shutdowns. Therefore, coal is required to have sufficient thermal stability.
It refers to the ability of coal samples of a certain particle size to maintain their original particle size when heated during high-temperature combustion or gasification.