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DEVELOPMENT OF AN ADVANCED CONTROL SYSTEM OF THE PROCESS OF AMMONIA SYNTHESIS Khalilov A.J. Email: Khalilov691@scientifictext.ru
Khalilov Azim Jurakulovich - Senior Teacher, DEPARTMENT OF HIGHER MATH AND INFORMATION TECHNOLOGY, NAVOI STATE MINING INSTITUTE, NAVOI, REPUBLIC OF UZBEKISTAN
Abstract: the article discusses the problems of developing a system for advanced control of technological processes for the synthesis of ammonia. These developments allow us to solve various problems of system analysis, optimization and control, which makes it possible to reach a new level of production process management. When developing a system for advanced process control of ammonia synthesis, a large amount of material was analyzed for the process under consideration. The analysis of approaches to solving the problems of constructing models and process control systems for ammonia synthesis is presented. Keywords: control system, advanced control systems, modernization, ammonia synthesis, uncertainty.
РАЗРАБОТКА СИСТЕМЫ УСОВЕРШЕНСТВОВАННОГО УПРАВЛЕНИЯ ПРОЦЕССОМ СИНТЕЗА АММИАКА
Халилов А.Ж.
Халилов Азим Журакулович - старший преподаватель, кафедра высшей математики и информационных технологий, Навоийский государственный горный институт, г. Навои, Республика Узбекистан
Аннотация: в статье рассмотрены проблемы разработки системы усовершенствованного управления технологическими процессами синтеза аммиака. Данные разработки позволяют решать различные задачи системного анализа, оптимизации и управления, дают возможность выйти на новый уровень управления технологическими процессами производства. При разработке системы усовершенствованного управления технологическими процессами синтеза аммиака был проанализирован большой объем материала по рассматриваемому процессу. Приведен анализ подходов к решению задач построения моделей и систем управления технологическими процессами синтеза аммиака.
Ключевые слова: система управления, системы усовершенствованного управления, модернизация, синтез аммиака, неопределенность.
UDC 62-503.56
Currently, automation of technological processes is becoming increasingly important. The creation of a modern automated control system using industrial controllers allows not only increasing the economic efficiency of the enterprise, but also makes it possible to reach a new level of production process management.
In some cases, the modernization of the control system using the latest digital computer technology is, unfortunately, limited only to replacing obsolete automation tools, while not all the features and functions that modern microprocessor technology has are realized. In addition, in most cases, the control methods and methods remain the same as they were before the modernization, which ultimately cannot lead to the best management of complex technological objects, characterized, for example, by the mutual influence between adjustable parameters, the presence of disturbances, unsteadiness of dynamic characteristics objects, etc.
The paper discusses the problems of developing a system for advanced process control of ammonia synthesis. In our country and neighboring countries, there are more than thirty
enterprises using the same type of ammonia synthesis reactor. This reactor is interesting, first, because it is a multidimensional control object, which is characterized by four inputs, four outputs and a significant number of disturbing influences. This, in turn, causes a number of difficulties in creating a control system and at the same time allows us to identify new ways to solve these problems.
One of the technological stages of ammonia production is the catalytic synthesis of ammonia in the column. The most important adjustable parameter is the temperature in the catalyst zone [1]. Temperature control is quite a difficult task, since the existing mathematical models are difficult to implement due to the complexity of the physicochemical dependencies. In addition, all parameters of the ammonia synthesis column vary over time.
As a research object, this work initially considered a typical chemical-technological system for the ammonia synthesis section. This chemical-technological system (CTS) was considered both separately and together with the section for the release of ammonia from purge gas. The process of producing anhydrous liquefied ammonia consists of the following stages:
- purification of the converted gas from carbon monoxide with liquid nitrogen -production of nitric mixture;
- compression of a mixture of nitric;
- synthesis of ammonia followed by cooling and condensation of ammonia gas to produce liquid ammonia;
- compression of process nitrogen;
- compression of carbon monoxide fraction and ammonia gas.
The technological scheme of the synthesis section is shown in fig. 1.
According to the technological regulations [2], the nitrogen-hydrogen mixture (NGM) necessary for the ammonia synthesis process is obtained by cleaning the converted gas from carbon monoxide, argon, methane with liquid nitrogen.
The maximum possible decrease in the temperature of the gas mixture and the improvement of the liquid ammonia separation conditions allows reducing the ammonia content at the synthesis column inlet and increasing the productivity of the column. The amount of ammonia formed corresponds to the difference of its content in the gas leaving the column and entering the column [3].
Fig. 1. Technological scheme of ammonia synthesis section
In this study, an advanced process control system for ammonia synthesis was developed and the following results were obtained (Table 1).
Table 1. Comparison table of technological indicators for the option of modernization with an
advanced control system
Parameters (technological indicators) Before modernization Traditional modernization Modernization with advanced control system
Production, tons per day 1350 1800 1890
Primary reforming
The temperature of the mixture of raw materials, oC 510 537 438
Outlet temperature, oC 820 810 706
Steam / Carbon 3.5 3.0 2.7
Secondary Reform
T air, oC 468 480 453
Methane yield, mol % 0.32 0.27 1.72
T at the exit, oC 1002 972 885
Synthesis circuit
CH4 in feed gas, mol % 0.83 0.97 not
Inertness in gas, mol % A 1.15 A 1.27 A 0.19
A Pressure in the circuit. Kg/cm2 (excess.) A 210 A 181 A 178
The main conclusions from the results of testing and trial operation of advanced process control systems are as follows. Thanks to the control of the installation using advanced process control systems, it was possible to:
• increases the productivity of the reforming system by 25-30%;
• more optimal use of high potential heat;
• with parallel execution, the pressure drop is reduced;
• can be used to increase productivity, with an increase of up to 50%, as well as reduce energy consumption;
• best suited when major deficiencies are identified in areas of the furnaces and synthesis loop;
• use of excess air in a secondary reformer;
• softening the conditions in the primary reforming unit - extending the life of the pipes;
• a new stage of cryogenic treatment;
• new parallel process air compressor;
• increased CO2 production;
• the use of pure dry synthesis gas allows achieving optimal conditions for increasing the productivity of the synthesis circuit and prolonging the life of the synthesis catalyst.
References / Список литературы
1. Ali D., Kayvan Kh., Mehdi A., MadjidK. Modeling and simulation of ammonia synthesis reactor. Petroleum and Coal. 48(2). P. 15-23. [Electronic Resource]. URL: https://www.researchgate.net/publication/229034628_Modeling_and_simulation_of_am monia_synthesis_reactor/ (date of access: 30.06.2020).
2. Permanent technological regulations № 24 of the complex 325 "A" of the third stage ammonia production (gas purification with liquid nitrogen, compression, synthesis). For educational and scientific purposes. Navoi: OJSC "NAVOIYAZOT", 2012. P. 14-32.
3. Demidenko I.M. and others. Ammonia: technology issues: production and practical publication / total. ed. Yankovsky N.A. Gorlovka: Concern Stirol OJSC, 2001. P. 108.
ПРИМЕНЕНИЕ ГРАФОВЫХ НЕЙРОННЫХ СЕТЕЙ ДЛЯ ПРОГНОЗИРОВАНИЯ ВОВЛЕЧЕННОСТИ ПОЛЬЗОВАТЕЛЕЙ В СОЦИАЛЬНЫХ МЕДИА Черкасов Е.И. Email: Cherkasov691@scientifictext.ru
Черкасов Егор Игоревич - магистрант, Институт информационных технологий Челябинский государственный университет, г. Челябинск
Аннотация: социальные сети стали местом, в котором можно влиять на общественное мнение. Из-за этого возникают задачи по анализу поведения людей в этих сетях. В данной работе рассматривается использование графов для анализа социальных сетей. Рассматриваются графовые эмбеддинги и графовые нейронные сети, их применение на практике. Проведены эксперименты по прогнозированию с помощью графовых нейронных сетей людей, которые поставят лайк на пост в социальной сети "ВКонтакте". Результаты показывают, что с помощью нейронных сетей не удалось повысить качество.
Ключевые слова: социальная сеть, вовлеченность, графовые эмбеддинги, графовая нейронная сеть.
USE OF A GRAPH NEURAL NETWORK FOR PREDICTING USERS INVOLVEMENT IN SOCIAL MEDIA Cherkasov E.I.
Cherkasov Egor Igorevich - Undergraduate, INSTITUTE OF INFORMATION TECHNOLOGIES, CHELYABINSK STATE UNIVERSITY, CHELYABINSK
Abstract: social networks have become a place where you can influence public opinion. Because of this, tasks arise in analyzing the behavior of people in these networks. This paper discusses the use of graphs for the analysis of social networks. Graph embeddings and graph neural networks, their application in practice are considered. Prediction experiments using graph neural networks of people who like to post on the social network "Vkontakte". The results show that using neural networks failed to improve quality. Keywords: social network, involvement, graph embeddings, graph neural network.
УДК 004
1. Введение
В наше время социальные сети стали серьезной площадкой для формирования и манипулирования общественным мнением. Большинство известных брендов имеют свои группы в крупный сетях и продвигают там свою продукцию и услуги. Помимо брендов в социальных сетях появились и лидеры мнений - частные лица, материалы которых отслеживает большое количество людей. Поэтому сейчас, в условиях высокой конкуренции, встает задача формирования определенного мнения аудитории.
