The uniformity of radiant tube surface temperature distribution is an important technical performance index to measure radiant tube. It affects the heating ability, heating quality and service life of radiant tube. At present, U and W radiation tubes are most widely used. Therefore, U and W radiation tubes are taken as research objects.

The original radiation tube is only installed at one end of the burner, the temperature difference between the two ends of the radiation tube is large. In order to improve the uniformity of temperature distribution on the surface of the radiation tube, a number of pellets were set in the radiation tube, which filled the radiation tube with high-temperature gas, strengthened the convection and heat transfer between the high-temperature gas and the tube wall, and increased the temperature at the tail. In order to improve the temperature uniformity of the radiation tube, burners were installed on both ends of the radiation tube. On the basis of pulse combustion, the uniformity of the temperature distribution of the radiation tube can be further improved by changing the combustion time of the two end burners.

The uniformity of surface temperature distribution is closely related to the length of flame. The initial burner can only conduct first-stage combustion, on the basis of which, a burner capable of two-stage combustion is improved to adjust the ratio of primary air and secondary air in the burner through the control system, which can effectively control the flame length and improve the uniformity of temperature distribution on the surface of the radiation tube.

The emergence of regenerative combustion technology has greatly improved the temperature uniformity of radiation tubes. It is found that with the increase of air preheating temperature, the maximum temperature difference on the surface of the radiation tube decreases gradually, and the temperature non-uniformity coefficient decreases accordingly. There are two lines of technological evolution in this process:

1) evolution route to supersystem: single system → double system → multiple system. Following this evolutionary path to improve the uniformity of temperature distribution on the surface of the radiation tube, the system is in the final stage of evolution.

2) the path of frequency coordination evolution: single object (flame) : continuous motion → pulse → periodic action → increase frequency → resonance. According to the evolution route description to improve radiation tube temperature distribution uniformity of the evolutionary process, the system is in the midst of a cyclical evolution stages, can further improve on both sides of the burner combustion cycle or to increase the frequency of the direction of development, such as increasing the frequency of the alternating on both sides of the burner combustion in order to improve the uniformity of radiant tube temperature distribution.