The method of unloading and reloading solidified oil fuels, with the use of pipelines made according to temporary technological schemes, produced in winter, is considered. Cooling of solidified fuels is accompanied by a sharp increase in their viscosity, which makes pipeline transmission impossible. In fire hazard, it is proposed to produce continuous heating of the pumped fuel using devices based on low-temperature combustion of propane-butane mixture on the surface of the catalyst carried out at fire-safe temperatures. It is also proposed to install a temporary heat-insulating shell on the pipeline that meets the operating modes of the heaters.
The device for year-round cooling of permafrost soils is designed to ensure the construction and operation of roads and railroads in the tundra zone. It includes pipes buried in the ground near the roadbed, a wind turbine powering an electric current generator, an absorption-type cooling unit, and an exhaust fan ensuring the flow of atmospheric air through the pipes. During the long and cold winter, the pipes laid in the ground provide deep freezing of the ground beneath a thick layer of snow. In spring and autumn, at temperatures close to 0°C, the air in the pipes is forcibly cooled by the cooling unit. In summer, at air temperatures exceeding 10°С, air movement through the pipes is blocked. In conditions of short summer, low levels of the sun above the horizon, the high albedo of snow and ice, and their low thermal conductivity, snow deposits remain on the ground throughout the summer period, and in the subsequent winters, accompanied by snowfalls, they intensify. Around a roadway built on permafrost, a protective snow layer is formed, preventing the flow of heat from the atmosphere and solar radiation into the ground. The protective layer can exist for decades, even if the Earth’s climate changes globally. The article presents hydraulic and thermal calculations, explaining the operation of the device in question.
Введение Для изучения поведения очередей в реальном времени на данный момент не существует универсальных решений. При возникновении неисправностей операторам связи приходится довольствоваться лишь косвенными признаками и сигналами о фактах переполнения пакетного буфера уже по факту [1, 2]. При анализе потока трафика в коммутаторе последний рассматривают как систему массового обслуживания (СМО). Поток трафика принято аппроксимировать пуассоновским потоком и для расчета очередей использовать известную формулу Хинчина-Поллячека. Но, как показывают исследования, потоки в сетях доступа, а тем более видеотрафик, не демонстрируют свойств пуассоновских потоков [3-5]. Для исследования потоков общего вида был предложен интервальный метод анализа трафика [6], в рамках которого получена обобщенная формула Хинчина-Поллячека, применимая к трафику сетей доступа. Цель данной работы-предложить алгоритмы для конвейерной работы данного интервального метода. В начале работы представлен алгоритм работы в режиме сколь-Инфокоммуникационные технологии и системы УДК 621.
The article discusses problems encountered in the carriage of viscous petroleum products at low temperatures and proposes solutions.
Aim: Construction of a mathematical model describing the business process; solution of the constructed problem using simulation.
Materials and Methods: The position of probability theory and mathematical statistics; the development of a mathematical model; the development of a simulation model using the Business Studio platform.
Results: mathematical and simulation models of the discharge of viscous petroleum products have been constructed showing possibilities of reducing the discharge time; the work of the enterprise was analyzed with additional equipment.
Conclusion: a function is defined, which returns the quantity of unloaded wagons, steam and electricity consumption; simulations are carried out.
В статье рассмотрены основные проблемы, связанные с транспортировкой и выгрузкой вязких нефтепродуктов железнодорожным транспортом при низких температурах. C учетом анализа применяемых технологий и моделирования в программе ANSYS протекающих процессов, предложено решение возникающих проблем за счет использования вагона-цистерны с парообогревательным кожухом или, с нанесением тепловой изоляции на верхнюю часть цистерны. Для обеспечения герметичности сливного прибора вагона-цистерны и исключения возникновения экологических катастроф, предложена модернизация его конструкции.
High viscosity petroleum products such as fuel oils and cracking residues are widely used as marine and boiler fuels both in Russia and in its exports. Conveying viscous petroleum products at low air temperatures has a high cost due to the unloading and cleaning processes of the transport tanks. Refined petroleum product cools and solidifies during transportation, becoming highly viscous, making it impossible to drain it without preheating to restore fluidity. Emerging difficulties are common to all countries with long winters and geographically wide areas. To justify a new method of rail transport of viscous petroleum products while maintaining their high temperature and fluidity by suppressing the natural convection of the petroleum product at the stage of filling the tanker. Temperature field calculations using the finite element method and the ANSYS R18.2 package are presented. The business process of the proposed transport method is universal for all modes of transportation. Using Petri nets and simulation modelling, it is investigated using the example of cleaning a tank car boiler from highly viscous residual oil products. You must perform these operations periodically during the operation of the tank wagon, and they are mandatory before every scheduled inspection and repair. Viscous oil products can be transported in a new way, the duration of the cleaning process of the tank wagon boiler is reduced by three times and the amount of water consumed is reduced by one and a half times.
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