When it comes to boilers, most people should be familiar with them. Those who are knowledgeable about boilers know that there are many types, with gas boilers and coal boilers being the most common. Many people struggle with the question of which of these two types of boilers is better. Here, I can only say that each has its own merits. Although both are boilers, there are still many differences between the two.

When it comes to boilers, most people should be familiar with them. Those who are knowledgeable about boilers know that there are many types, with gas boilers and coal-fired boilers being the most common. Many people struggle with the question of which of these two types of boilers is better. Here, I can only say that each has its own merits. Although both are boilers, there are still many differences between the two.

1. Combustion Method

A coal-fired boiler, as the name suggests, primarily burns coal. A gas boiler uses a mixture of coke oven gas and waste gas, injected directly by four burners.

2. Combustion Products

Coal-fired boilers produce SO2, SO3, NOx, ash, and moisture, which pollute the environment. Gas boilers mainly produce CO2 and H2O after combustion, and the emissions of SO2, SO3, and NOx in the flue gas of gas boilers are much lower than those of coal-fired boilers.

3. Ventilation Method

Coal-fired boilers typically use negative pressure combustion, and the basic combustion process is completed by both the fan and the induced draft fan. A large amount of air is needed during the coal combustion process. Due to air leakage from the furnace wall and flue, the excess air coefficient can reach 2.1-2.5. Gas boilers use slightly positive or slightly negative pressure combustion, requiring very little air volume, and the air in the burner can be fully premixed with natural gas. During slightly positive pressure combustion, there is no air leakage coefficient from the furnace wall and flue, and the air coefficient at the flue outlet during operation can be 1.05-1.20.

4. Fuel Explosiveness

Coal-fired boilers are safe to burn and are not prone to explosions. Gas boilers can explode when exposed to an open flame.

5. Boiler Automatic Control

Due to factors such as coal type, material layer thickness, air volume, induced draft volume, and air-coal ratio, it is difficult for coal-fired boilers to automatically adjust boiler operating parameters based on load. Gas boilers are less affected by these factors. The valve size of the burner can be adjusted according to the load, making it easier to achieve automatic control.