There is an article about adding water to coal; please share your opinions.

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http://www.nyyjn.org/jienengjianpai/120.html This is an article about adding water to coal; it represents a concept completely different from the practice of intentionally adding water to coal in reality. Could it be that our actual approach is wrong? Please share your opinions on the measure of adding water to coal. The article reads as follows: Adding water to coal – a major no-no for boiler combustion and energy savings. Author: Zhang Xiaojing. Published on: 2012-6-19 16:33:10. Views: 2. Source: Energy and Energy Savings. Abstract: Adding water to coal affects the normal combustion in boilers, reduces their thermal efficiency, and exacerbates low-temperature corrosion. 　　Keywords: moisture; combustion; heat loss 　　0 Introduction 　　As is well known, the heat released when coal burns in a boiler is its lower heating value. This is because the water contained in coal absorbs the heat from the coal during combustion and turns into water vapor. Therefore, the more moisture contained in coal, the lower its calorific value. In other words, the moisture in coal is entirely harmful and offers no benefits for boiler combustion. 　　1. The effect of moisture in coal on boiler combustion The impact of moisture in coal on boiler combustion is as follows: a) it reduces the furnace temperature, which affects the stability of combustion. Because the more moisture in the coal, the lower the furnace temperature, and the more difficult it is for the coal to burn; b) Increase the volume of the flue gases: When water is evaporated into water vapor, its volume increases by 1600 times at normal pressure (100°C). This will greatly increase the volume of flue gas, resulting in increased flue gas exhaust resistance, higher current consumption in the exhaust fans, and increased heat losses during flue gas exhaust; c) it raises the dew point temperature of the flue gas at the rear of the boiler, thereby exacerbating low-temperature corrosion of the heating surfaces at that location. According to available information, as the volume fraction of water vapor in the flue gas increases, the dew point temperature of the flue gas also rises. For example, when the volume fraction of water vapor increases from 2.3% to 9.3%, the flue gas dew point temperature rises from 75.8°C to 100.3°C, resulting in a difference of 24.5°C; d) Increasing the excess air coefficient: Under normal conditions, the excess air coefficient in a boiler furnace is between 1.2 and 1.4. When the considerable amount of moisture contained in coal evaporates into water vapor, it increases the excess air volume in the furnace significantly, carrying away a large amount of heat and thereby causing a noticeable drop in the boiler’s thermal efficiency. 　　3 Conclusion In our work, we found that some boiler operators deliberately add water to the coal before feeding it into the boiler. The idea is to let the added moisture produce water gas in the furnace, thereby aiding combustion. In fact, this idea is incorrect. The main components of water gas are H2 and CO, which are produced by the reaction of steam with red-hot anthracite or coke. And the water in coal cannot be used to produce water gas in a boiler. Typically, the moisture content in coal ranges from 3% to 18%. Therefore, facilities that have the means to do so should install dry coal storage areas to prevent the moisture content in coal from increasing during rainy weather. During boiler operation, it is even more unacceptable to add water to the coal artificially. Remember: Adding water to coal is a major no-no for boiler combustion and energy savings. Of course, this also applies to all stoves that use coal as fuel. 　　References: 1. Li Jun, Yan Weiping, Gao Baotong, Wang Qiong, \"Thermal Power Generation,\" Issue 4, 2009, pages 31-34. 2. Lin Zhonghu, Zhang Yongzhao, \"Boiler Manual,\" Mechanical Industry Press, February 1989, Chapter 3, page 123