Application of electric heating cables in chemical devices
In chemical production equipment, the differential pressure flow meter is the most widely used flow meter, especially throttling is the most popular application of the detection part in the differential pressure flow meter as a standard throttling device. It is one of the instruments with limited attention in the selection of flow meters. The operating principle of the standard flow throttle device is to install the throttle on the process line and form a static pressure drop before and after the throttle element, with the static pressure drop being transmitted to the differential pressure transducer via two measuring tubing and converted into a standard signal, namely the measured flow rate, since the material in the measuring pipeline is in a static state, When the ambient temperature is below the freezing point of the material, it is necessary to heat the pressure inlet pipe and the transducer to prevent the freezing of the instrument and affect the normal operation of the flow meter measurement system, and thus hinder production.
Traditional heating methods of differential pressure flow meter mainly include: hot water heating, steam heating, and electric heating. Due to the many shortcomings of steam and hot water heating systems, an electric heater has become a very popular method of heating.
Electric heating is the use of an electric heating belt or other electric heating devices to replenish the heat lost by a heated object during operation in order to maintain the temperature of the medium within a certain range. Electric heating system consists of power supply, electric heating cable and electric heating system., workroom, compare the temperature measured by the temperature sensor above the pipeline with the temperature set by the temperature controller, and disconnect or connect the power supply in time by controlling the contactor to achieve the effect of heating and antifreeze. Since electric heating is a heating method in which electrical energy is converted into thermal energy, it is safer and more reliable, convenient for construction, and can effectively control the temperature to prevent local overheating.
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.