Thermal oil heater is a kind of new heat energy equipment with low pressure and high temperature, playing an important role in various industries. The thermal oil heater has wide adaptability of fuels, is suit for natural gas, coal gas, marsh gas, diesel, light oil, etc. The heat exchange surface adopts three-pass round coil tube structure, which features more sufficient heating surface. It is also equipped with an advanced burner to ensure the NOx emission below 30mg/m3. The waste heat boiler, air pre-heater and economizer are installed on the tails of the thermal oil heaters to effectively improve thermal efficiency, which can reach above 98%.