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Coking is a common problem in boiler operation. During the combustion process, the fusible or volatile substances contained in coal powder particles rapidly vaporize and enter the flue gases. When the temperature drops, these substances condense; they either adhere to the heated surfaces or furnace walls exposed to the flue gas flow, or they condense on the surface of fly ash particles, forming a molten alkaline film. This film then adheres to the heated surfaces, creating an initial layer of coking, which provides the conditions for further coking to occur. Under normal circumstances, the ash particles that move along with the flue gas are cooled together with the flue gas due to the heat absorption by the heated surfaces of the furnace’s water wall. If the liquid slag particles solidify as the temperature drops before reaching the water wall or furnace lining, and then diffuse to the heated tube walls in a solid state, a loose ash layer is formed, which can be easily removed during operation by soot blowing. When the temperature inside the furnace is high, some ash particles are in a molten or semi-molten state. These particles do not cool sufficiently before reaching the heated surfaces to solidify, and as a result they possess high adhesion properties; they tend to stick to the heated surfaces or furnace walls, even remaining in a molten state. The presence of these molten or semi-molten ash particles along with unburned coke facilitates the progression of coking from isolated spots to larger areas, leading to the formation of large clumps of coke. Based on an understanding of the principles behind furnace tube coking, Beijing Zhisheng Weihua Chemical Co., Ltd. has developed the ZS-high-temperature resistant far-infrared radiation coating, which is used to effectively prevent the formation of coke deposits. Based on numerous application cases, Beijing 136 Zhisheng 6102 Wei Hua 1263 Tang Gong have conducted the following analysis regarding the use of ZS – high-temperature resistant far-infrared radiation coating spraying technology to prevent coking: The factors contributing to coking are complex, and the basic principle for preventing coking is to eliminate the conditions that lead to its formation. If the high-temperature flue gases in the furnace do not scour the water wall or heating surfaces, or if the molten ash particles have cooled and become solid or non-adhesive before coming into contact with the wall tubes, or if an oxidizing atmosphere is created near the water wall and heating surfaces to raise the ash melting point, or if the surfaces of the water wall and heating surfaces have good anti-coking properties, then coking will not occur. Therefore, to prevent coking in the middle and lower parts of the furnace, efforts are primarily focused on improving aerodynamic conditions, reducing the formation of a reducing atmosphere, and enhancing the anti-coking properties of the water wall surface ； Preventing coking in the upper part of the furnace mainly relies on reducing the flue gas temperature or improving the anti-coking properties of the water wall surface. 1. After spraying the ZS-high-temperature resistant far-infrared radiation coating on the furnace water wall, its blackness of 0.93 is 0.23 higher than that of conventional metal tubes used for water walls; this increases the heat absorption capacity of the furnace water wall, reduces the temperature of the smoke near the wall, and enhances the ability to cool the molten ash. As a result, the molten ash transitions to a semi-molten or solid state during diffusion, reducing its adhesion capacity and thereby effectively preventing or avoiding coking ； 2. The ZS-high-temperature resistant far-infrared radiation coating is used on the surface of the furnace water wall. Since ZS-high-temperature resistant far-infrared radiation coating is a non-metallic material, its thermal resistance is slightly higher than that of metal tube walls; this slows down the heat transfer from the molten ash particles to the tube walls, preventing rapid heat release that could lead to solidification and coking. 3. The ZS-high-temperature resistant far-infrared radiation coating is manufactured through nanomization, and thus possesses the characteristic common to nanomaterials: low surface energy. This reduces the surface energy of its coating compared to that of the original metal tube wall surface, making it difficult for molten coke particles to adhere to the heated surface. This prevents contamination of the water wall, thereby effectively avoiding or reducing coking. Even with a small amount of coking, due to the low surface energy of the wall surface, the coke particles fall off on their own once they reach a certain size, exceeding the critical value for adhesion; as a result, large chunks of coking cannot form. After spraying the ZS-high-temperature resistant far-infrared radiation coating in the water wall area, this coating enhances radiative heat transfer and increases the temperature gradient in the near-wall region and the combustion zone. By appropriately increasing the heat absorption of the furnace water wall, the flue gas temperature at the furnace outlet is reduced accordingly, which minimizes or eliminates the formation of molten ash in the flue gas. This allows the ash to solidify before it comes into contact with the screen, thereby preventing or reducing the formation of slag on the water wall and the surface of the screen. At the same time, due to the nanological properties of the ZS-high-temperature resistant far-infrared radiation coating, the smoothness of the coating is improved, which effectively prevents sticking and contamination. From the above analysis, it is clear that the ZS-high-temperature resistant far-infrared radiation coating is effective in preventing and reducing coking; its properties can be utilized to benefit coal-fired boilers with severe coking problems.