Based on the heat loss occurred when a pipeline to transport hightemperature steam vapor overhead, it is established physical and mathematical models of steam pipeline,and compared to the three commonly used insulation materials of overhead pipeline. Research results showed that the application results of nano airgel composite reflective insulation was the best. The different steam temperatures of the temperature field of pipeline and insulation layer in, different diameter and different insulation thickness distribution were simulated. By analyzing the temperature field indicated that changing the diameter effected the heat loss of overhead vapor line greatly. When the diameter changed from 126 mm to 132 mm unit length, the heat loss increased 10.702 62 kJ/(h •m).

When buried pipeline was running, there were many factors could cause shutdown phenomenon. This could cause serious economic losses. Oil temperature and soil temperature were the important parameters for pipeline shutdown security. So it was significant to study oil temperature field and soil temperature field for the safe operation of buried pipeline. It was simulated that the excavation area temperature during the shutdown of the pipeline. And the simulation was threedimensional. Calculation areas contained three parts: soil area, pipeline internal area and the excavation area. These temperature fields were changed after excavation. And the changes of these three areas were simulated. The safety shutdown time was obtained by pipeline internal oil temperature changes. The oil temperature was declined after excavation. The influence of excavation area was obtained by observing the oil temperature. The temperature decline reflected the influence range. The results provided a reference for the safety production.

For high temperature steam vapor transport in the buried pipeline causes heat loss and leads to energy waste problems，several factors affecting heat loss were analyzed. Steam pipeline of physical model and mathematical model was established to simulate the different steam temperatures，different buried depth and temperature distribution under different insulation thickness. And temperature distribution pipeline and the surrounding soil were calculated and analyzed under different conditions. The results show that the heat loss of buried steam lines with the steam temperature, buried depth, changed the thickness of the insulating thickness changes，and the biggest affect of the heat loss was the insulation thickness. When the insulation thickness was from 40 mm to 80 mm，the heat loss per unit length declined 110.591 W/m，and the thermal effect was smaller and smaller .