Before coal is selected to be used in steam power plants, these are some of the properties that should be met.
In this article, I will share the properties of coal that is to be used in the steam power plants.
As you know, coal needs to be selected appropriately to ensure that the amount of energy produced is enough to keep the process of energy production going.
Selecting coal with the wrong properties is going to affect the overall performance of the power plant.
Now that you know that, let me share some of the properties that should be observed when selecting coal for steam power plants.
Selection properties of coal to be used in steam power plants;
1. Size and grade of the coal.
When selecting coal to be used in steam power plants, one should think of the type of equipment that will be used to burn it.
So, if the coal is going to be pulverized, the size and grade of the coal selected to be used should be small size and grade to make the process of pulverization easier.
You might like this: Pulverized Fuel Burner: Components, Types, Requirements and Working Principle
But if the equipment used to burn the coal requires the coal to be of big chunks, then that should be considered.
For instance, if the coal is to be fed by a hopper to the furnace, then the coal has to be of a size and grade that is not going to allow its wastage.
The type of equipment and the firing system used plays a big role in the selection of the size and grade of the coal used in the steam power plants.
2. The heating value of the coal.
When selecting coal to be used in steam power plants, this is another property that should be analyzed.
The coal selected to be used in the steam power plant has to be of higher heating value.
The heating value (calorific value) being higher indicates that the amount of energy produced by the coal is higher.
While the low calorific value of the coal indicates that the energy produced during the combustion of the coal is lower.
Selecting coal with a high calorific value increases the overall efficiency of the steam power plant since the energy used to generate the steam will be sufficient.
3. The products of combustion of the coal selected.
The coal selected to be used in the steam power plant should not produce ash at higher temperatures.
The temperature of the ash produced by the coal during combustion plays a big role in the slagging characteristic of the final products of combustion.
Also, the Sulphur content of the coal selected to be used in the steam power plant should be lower.
This ensures that the corrosion in the furnace is reduced significantly, thus decreasing its maintenance.
4. Coking and the caking tendency of the coal.
The coal selected to be used in the steam power plant should not change its shape during coking and caking.
It should retain its original size and shape during combustion and softening.
5. Physical properties of the coal.
Earlier, I talked about the size of the coal being one of the properties that are observed when selecting coal to be used in a steam power plant.
What will be the point of observing this property if it’s going to keep on changing as the coal is used in the furnace?
The coal selected to be used in a steam power plant should offer resistance to degradation as it’s used.
The grade and size of the coal should not change as it’s being used in the furnace.
The size should be consistent throughout since the coal was earlier selected depending on the type of equipment that is going to be used to burn it.
Change in the size of the coal during combustion is going to affect the overall efficiency of combustion negatively.
The coal selected should offer resistance to degradation and be of the same size as it’s being fed in the furnace and used.
6. Grindability of the coal.
Grindability is the ease at which the coal selected to be used in the steam power plant can be pulverized.
This property of selection is mainly going to depend on the type of equipment that is going to be used to burn the coal.
If pulverized firing system is going to be used, then the grindability index of the coal should be higher.
You might like this: Pulverized Fuel Burner: Components, Types, Requirements and Working Principle
The grindability index is the number used to measure the ease of the coal being pulverized.
Lastly…
The properties of the coal selected to be used in the steam power plants should be observed keenly because they affect the overall efficiency of the power plant.
The coal provided in the steam power plant contributes to the energy used to generate the steam needed to drive the turbines; if the properties of the coal aren’t carefully observed, the combustion rate is going to be affected.
When that happens, the steam generation is going to be affected negatively, thus decreasing the efficiency of the steam power plant.
So, every property that is supposed to be observed in the coal selected to be used in the steam power plant should be carefully considered.
If you have any questions, leave a comment. See you in my next article.
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