In the petroleum industry, steam is the main factor affecting the energy consumption of enterprises. Jinxi Petrochemical is affiliated to China National Petroleum Corporation. ZOZEN provided the company with SHL series field assembled water tube steam boiler. This series of boilers has wide coal adaptability, the boiler water circulation adopts all-natural circulation, and each heating surface has relatively independent down comers to supply water, ensuring the safety of the overall water circulation. The large furnace design can extend the residence time of the flue gas in the furnace to make the full combustion of the fly ash and combustible gas. In addition, the flag pattern heating surface absorbs the temperature of the flue gas to a large extent, which improves the thermal efficiency of the boiler.