Air supply urea pyrolysis system for natural gas hot blast heater

The utility model discloses an air supply urea pyrolysis system for a natural gas hot blast heater. The system comprises a urea solution conveying device and a hot air conveying device which are respectively communicated with a pyrolysis chamber, wherein the urea solution conveying device comprises a urea solution preparation device, a urea solution metering distribution device and a urea solution jet device which are sequentially connected with one another by virtue of pipelines; the hot air conveying device comprises a heater and also comprises a hot blast heater communicated with the heater; and the outlet of the hot blast heater is connected with the pyrolysis chamber by virtue of a hot air pipeline. According to the system, the flow field of hot air entering the pyrolysis chamber is not influenced by change of natural gas load and change of the quantity of cold air and primary air, a backflow phenomenon is avoided in the pyrolysis chamber, stable decomposition reaction conditions in the pyrolysis chamber can be guaranteed, and the phenomenon that lots of isocyanic acid is produced at the outlet of the pyrolysis chamber so as to cause blockage is avoided.