YLW coal fired thermal oil boiler is a kind of new type heating equipment, the fuel could be coal, biomass or flue gas, the heat carrier is heat conduction oil, the circulating pump force heat transfer medium circulating in liquid phrase, and transfer heat to heat user equipment, then return to the heating furnace for reheating. It is an safe and low energy consumption boiler with working characteristics of low pressure (1.0 MPa) and high temperature (350℃). The boiler medium is working under liquid state, so it is safe and reliable.