Application of heating cables for snow melting on roads and ice melting on roofs
The inner core of the heating cable consists of cold and hot wire, and the outer part consists of an insulating layer, a ground layer, a shielding layer, and an outer shell. As for heating cables, single core and double core are most often used. The structure of the single terminal is such that the cable enters from the "cold wire", sequentially connects the "hot wire", and then connects the "cold wire" to the lead. A single-core heating cable is characterized by a "head and tail," both of which are "cold wires" for connecting to a thermostat. The two-core heating cable comes from the "cold wire", connects the "hot wire" in series, and then returns from the "cold wire" in the cable. Its peculiarity is that the head and tail are at the same end.
road snow melting
When the road in front of the house has a large slope, when snow or frost falls in winter, it will be difficult and dangerous for vehicles to rise and descend the slope. If we lay heating cables under the rut of this slope section of the road to melt the snow and ice, then such difficulties and dangers will be effectively resolved. Changchun installed heating cables in the overpass with a slope of 4% and achieved good results. The use of snow melting technology with heating cable on airport runways was relatively extensive and mature.
The melting of snow and ice on the cornices and roofs
Ice and snow will cause serious damage to the roof, and heavy snow will increase the load on the roof of the large-span building and, if it is not melted in time, will cause a dangerous building. On the cornishes during snow melting in the northern regions, there is often ice skating, the length of which sometimes reaches 1 m and weighs more than ten kilograms, and it is very dangerous to break and fall. The roof and cornices can effectively prevent the danger from snow and ice. Civilian buildings suitable for using heating cables for snowmelt roofs include rescue centers, hospital roofs, helipads, glass roofs, flat roofs, large-span structural roofs, simple roofs for pedestrian crossings, roofs (to prevent ice injury), special figured roof, etc.
Heating cables are widely used not only in industry but also in civil buildings and have shown their high viability. Combined with the current engineering situation, heating cables are mainly used in parking lots, equipment floors, elevators in civil buildings insulation of indoor machines, pipe wells, etc. D., as well as snow melting for school wind and snow areas, building roofs, underground garage ramps, etc. D. As this technology improves and people are aware of it, the range of its application in civilian buildings will further expand. It is believed that the application of this technology will bring more safety and comfort to people's lives and will be a new bright spot in the green construction that we advocate for.
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.