Abstract:In order to reduce the energy consumption of the steam transmission in the pipeline,an insulating coating having photonic crystal structure is designed.The steam radiates electromagnetic waves with specific wavelengths of 4007.1~7765.7 nm.Common Si and SiO2 are used as the medium.Calculation using transfer matrix method shows that:when the two medium are of 4 layers respectively,with geometric thickness of 410.5 nm and 972 nm respectively,there would be a strict band gap within 4450~7600 nm,and it has better angle tolerance.When the geometric thickness of two medium increases,the band gap would have red shifts and wider width,and vice versa.When the coating structure is ababa type,the photonic crystal forms a strict band gap between 4597.2~7305.6 nm.With the increasing medium layers,there would be no substantial change to the band gap,therefore,that ababa coating structure is the most economical.