The working principle of the boiler is more complex, mainly consisting of fuel system, smoke air system, soda water system and so
on.Different types of boilers have different working principles.According to the object size of heating and service, it can be
divided into the following three categories:
1. Household boilers are mainly electric boilers (electric hot water boilers), small gas-fired boilers, wall-hung boilers, etc.
2, residential, hospitals, companies and other central heating boilers are mainly gas boilers, steam boilers;
3. Large heating units include coal-fired boilers, oil-fired boilers, gas-fired boilers, steam boilers, etc.