Winter station awning siphon snow melting electric heating
With the development of high-speed rail in the northern region, major railway station buildings were also built and rebuilt one by one. Many of the large-scale station buildings use the platform canopy design as a steel structure without the platform column canopy., which covers a large area. Among them is a curtain roof drainage system. It is especially important to customize and how to solve the problem of winter snow in the northern region.
Most drainage forms of the column-free canopy are siphon drainage, which has become widespread. On the example of the high-speed railway station reconstruction project in the north, the total estimated area of the colonless shed is 80,000 square meters, covering 9 aprons and 16 railway tracks. The main structure of the canopy is a steel pipe column of the steel pipe truss. The truss has a total of 5 spans, including 3 spans in the normal field and 2 spans in the high speed field. The width is 60 m, the minimum span is 30 m.
The canopy roof panel is made of aluminum-zinc steel sheet, and the ceiling plate above the platform is made of aluminum slat. The drainage system is made of siphon, and electric heating lines are laid in the gutters and drainage risers, a total of 80 sets of risers. They mainly solve the problem of drainage in the rainy season and melting snow in winter.
The winter temperature in the area (December to the end of January next year) can reach-33 °C, the average temperature is about-19 °C, the average snowfall is 38mm, and the maximum snowfall can reach more than 50mm. The 18.5 W/m TXLP series heating cables are laid horizontally along the entire length using trough electric heating.
The riser uses 20 W/m constant power electric heating wire with mixed internal and external winding, and the method of outsourcing insulating materials. The maximum temperature of electric heating is 65 ℃ and the temperature inside the pipe is 5 ℃.
After several spring thaws, the drainage system was not affected by freezing. Problems such as icing over the line after snow has passed, and the drainage system is stable and reliable, ensuring the operation of the existing line is safe.
Electric heating cable is a heating method that uses insulation resistance or resistance heating wire to create a temperature after power supply. It can automatically adjust the output temperature and reasonably maintain the process temperature requirements to keep warm, raise the temperature and protect the heating equipment from freezing. The insulation and antifreeze effect of the container is very good.
Transport of heavy oil through the pipeline over long distances and long-term retention in the pipeline will result in a drop in temperature due to heat dissipation and increased viscosity, which will cause the pipeline to be blocked by freezing or condensation-related accidents. Electric heating is widely used as effective insulation of pipelines and anti-freeze protection.
According to the statistics of the Hydrometeorological Center, the average daily minimum temperature at the location of the CNPC tank farm is 5 ° C, and the average daily maximum temperature is 14 ° C. Since the freezing point of the PX is about 15 °C, the supply pipeline needs heat preservation and heating. The oil depot has been in operation for many years without a stable source of steam, therefore, this project is considering the use of electric heating technology.
Long-distance crude oil pipelines with a high paraffin content with freezing temperatures above 50 °C. According to the requirements of the production plan of the plant, the volume of oil transportation through the pipeline is 150 thousand rubles. Tons per year, maximum-200 thousand. Tons per year.. According to the thermodynamic analysis of the pipeline, the initial supply temperature of the pipeline is 80 ° C (TN), and the temperature of the end entering the tank is 60 ° C (Tu). Since the transportation temperature needs to be adjusted according to the time of year, it sometimes needs to be transported by heat.
In petrochemical engineering, trunk infusion pipelines are the lifeblood of the factories. The temperature in the northern region is too low in winter and the pipeline needs to be insulated to compensate for the heat loss due to the low temperature in winter to ensure the normal operation of the pipeline.
The toughness of the asphalt is greatly affected by the temperature. When the temperature decreases, the toughness of the asphalt increases, and the drop in resistance of the asphalt during pipeline transportation increases; when the temperature falls below the freezing point, the asphalt solidifies, causing the pipeline to clog and the conveyor belt to come to trouble. Therefore, electric heating and heat preservation during the transportation of asphalt are very important.
To solve many problems in the "three high levels" crude oil extraction process, the thermal energy generated by the electric heating is used to heat the crude oil in the oil pipe throughout the process to improve the fluidity of the crude oil. Effectively solve various technical problems encountered in the operation of high-condensation, high-viscosity and high-paraffin crude oil, and achieve the goal of improving the productivity and efficiency of oil wells.