what is the effect of moisture in coal on its calorific value. Is there any exact relationship between moisture, ash content and Calorific value of coal?
Put in simplistic terms, all that is not coal does not burn and provide a calorific value. Obviously, ash doesn't burn, so it displaces coal that could burn. And beyond that, moisture not only displaces coal, it requires some of the calorific value of the coal to heat it to the combustion temperature of the coal.
This paper is on the amount of Hg found in different coals. but also contains some specific caloric values.
The USGS at tone time published a lot more specific data that contained all of the coal sub groups.
The combustion temperature I was referring to in the earlier post is the flame temperature or at least the furnace exit gas temperature. The coal has to provide the necessary energy to heat the moisture along with all the rest of what goes into the boiler heat transfer surface.
