EFFICIENT CONTROL OF FUNCTIONING OF ELECTRICAL GAS PREPARATION COMPLEX TO TRANSPORTATION BY MAIN PIPELINE

The article discusses the problem of increasing the effi ciency of the linear section of the main gas pipeline system by developing eff ective control algorithms for the operating modes of the gas cooling unit. To develop control algorithms for a gas cooling unit, adapted mathematical models of thermal processes in air-cooled gas devices and in a gas pipeline are used. It is shown that when considering the dynamic modes, the gas pipeline system can be represented as consisting of two dynamic links. The link “gas cooling unit”, which includes up to 24 electric drives with heat exchangers, is characterized by relatively short time constants. In the main gas pipeline, heat exchange processes proceed much more slowly. This circumstance allows the main att ention to be focused on the development of an eff ective control system for the cooling plant. The control is carried out by discrete or continuous change in the fl ow rate of the cooling air through the heat exchanger by adjusting the number of switched on air coolers and changing the fan speed. The search for control algorithms for air coolers is carried out by formulating and solving the problem of minimizing the root-mean-square deviation of the gas temperature at the outlet from the heat exchanger from the required value. To implement the obtained control algorithms, a functional diagram of the automatic control system for the operating modes of the gas cooling unit has been developed.

DEVELOPMENT OF METHODS FOR ANALYZING AND ENSURING THE RELIABILITY OF GAS DISTRIBUTION SYSTEMS IN THE TASKS OF INTEGRATED POWER SUPPLY OF LARGE TERRITORIAL FORMATIONS

Актуальность обусловлена, с одной стороны, необходимостью активной газификации крупных территориальных образований (строящихся новых жилых агломераций, коттеджных и дачных поселков, а также крупных промышленных комплексов). С другой стороны, продолжается увеличение общей протяженности газораспределительных систем и усложнение конфигурации схем газопроводов. Перечисленные факторы влияют на надежность работы газораспределительных систем и предъявляют высокие требования со стороны потребителей энергии к безаварийной их работе. Цель. Основная исходная надежностная информация, используемая для анализа надежности газопроводов, - это интенсивности отказов его элементов: отдельных участков линейной части, газоперекачивающих агрегатов и т.д., и интенсивности восстановления этих элементов. Эти показатели характеризуют такие свойства надежности как, безотказность и ремонтопригодность. Цель исследований заключается в оценке влияния показателей безотказности и ремонтопригодности оборудования на интегральные показатели надежности газораспределительной системы (ГС). К ним относятся математическое ожидание, дисперсия и среднеквадратическое отклонение (с.к.о.) пропускной способности ГС, а также коэффициент надежности газопровода. Методы: эквивалентирования, аналитический метод на уровне случайных Марковских процессов - схема «гибели и размножения», теоремы сложения и умножения вероятностей, композиция рядов распределения; математическая модель анализа надежности проектируемого магистрального газопровода (МГ). Результаты. На основе математической модели оценки надежности проектируемого магистрального газопровода и разработанной вычислительной программы были выполнены расчеты по определению интегральных показателей надежности условной газораспределительной системы. Исследования показали, что при изменении исходных показателей надежности (интенсивностей отказов и восстановлений) элементов ГС на одинаковую величину их влияние на изменение интегральных показателей надежности ГС имеет разную силу. Выводы. На основе предложенной математической модели анализа надежности ГС показано влияние показателей интенсивности отказов и интенсивности восстановлений элементов, характеризующих безотказность и ремонтопригодность газотранспортных систем, на ее интегральные показатели надежности, в частности, на коэффициент надежности. The Relevance of the research is due to the need for active gasification of large territorial entities (new residential agglomerations under construction, cottage and dacha settlements, as well as large industrial complexes). On the other hand, the increase in the total length of gas distribution systems and the complexity of the configuration of gas pipeline schemes continues. These factors affect the reliability of the gas distribution systems and place high demands on the part of energy consumers for trouble-free operation. Purpose. The main initial reliability information used for analyzing the reliability of gas pipelines is the failure rates of its elements: individual sections of the linear part, gas pumping units, etc., and the recovery rates of these elements. These indicators characterize such properties of reliability as reliability and maintainability. The purpose of the research is to assess the impact of reliability and maintainability of equipment on the integral reliability indicators of the gas distribution system (GDS). These include the expectation, variance and standard deviation of the throughput of the GDS, as well as the reliability coefficient of the pipeline. Methods: equivalent methods, analytical method at the level of random Markov processes - the scheme of "death and reproduction", the theorem of addition and multiplication of probabilities, the composition of distribution series; mathematical model of reliability analysis of the designed main gas pipeline. Results. On the basis of a mathematical model for assessing the reliability of the designed main gas pipeline and the developed computational program, calculations were performed to determine the integral indicators of the reliability of the conventional gas distribution system. So, studies have shown that when the initial reliability indicators (failure rates and recoveries) of the GDS elements are changed by the same amount, their effect on the change in the integral reliability indicators of the GDS has a different effect. Conclusion. On the basis of the proposed mathematical model for analyzing the reliability of the GDS, the influence of the failure rate indicators and the recovery rate of elements characterizing the reliability and maintainability of gas transmission systems on its integral reliability indicators, in particular, on the reliability coefficient, is shown.

REGULATORY PROVISION OF SAFETY OF GAS TRANSPORT. CONSTRUKTIONAL DESIGN OF MOBILE COMPRESSOR STATIONS

Problem statement. The basis for the safety and efficiency of the main gas transportation in the world is the tightness of the gas transportation system. A component of the level of industrial safety and efficiency of gas transmission enterprises is the emissions of natural gas into the working area, the environment and the associated costs. Numerous methods of repairing pipeline gas transportation facilities, such as enhancing the bearing capacity of pipelines, repairing defects under gas pressure without interrupting the transportation process, etc., are either not devoid of risks from the point of view of industrial safety, or are energy and resource inefficient. The main type of repair that restores the operable state of the gas transmission system is the replacement of defective equipment, but it is still associated with the release of large volumes of natural gas into the environment. In the second decade of the 2000s, thanks to the rapid development of compressor technology and the invention of a sufficient number of ways to connect compressor units (stations) to main gas pipelines, without stopping the gas transportation process, gas transmission enterprises of the world had a real opportunity to evacuate gas from pipeline sections subject to repair (maintenance ) or accumulate it (control gas pressure in local areas), but the analysis of world experience in the development of gas pressure control technology in localized sections of gas pipelines allows us to assert that there are certain disparities between them in terms of operational safety and the complete absence of regulatory support for the transportation process in Ukraine gas using mobile compressor stations. With this approach to the production process, it is difficult to improve the safety and efficiency of the gas transportation process. The potential for reducing natural gas emissions from the world's gas industry reaches billions of cubic meters of natural gas per year. Purpose of the article. Development of technical requirements for mobile compressor units (stations), which will make it possible to design domestic gas compressor units (stations) capable of safely performing work on pumping natural gas from a localized section of the main gas pipeline to an existing main gas pipeline, within no more than 96 hours, without restrictions on gas supply to consumers. Conclusion. The technical requirements developed by us for mobile compressor units (stations) allow us to design domestic compressor units (stations) capable of safely performing work on pumping natural gas from a localized section of the main gas pipeline to the existing main gas pipeline, within no more than 96 hours, without restrictions on gas supply to consumers.

JUSTIFICATION OF THE USE OF THE ELECTRIC DRIVE AT THE COMPRESSOR STATIONS OF THE MAIN GAS PIPELINE

The situation with the drive of compressor stations of main gas pipelines is analyzed. Based on the calculations carried out, a conclusion is made about the efficiency of using electricity for gas pumping

Conjugates (Charophyta, Conjugatophyceae) of the Kader bog (Leningrad region, Kurgalsky reserve)

The Kurgalsky Nature Complex Reserve is located in the Kingisepp District of the Leningrad Region, 45 km northwest of Kingisepp. The territory of the reserve includes the Kurgalsky peninsula, as well as the adjacent waters of the Gulf of Finland. The Kader swamp massif is located in the south of the Kurgalsky Peninsula. The state of the autochthonous vegetation cover of the Kader swamp was considered in connection with the laying of the main gas pipeline under «the Nord Stream–2» project. The revealed high diversity of desmids (48 species), as well as their abundance, the frequency of occurrence and the presence of species rare in other habitats of the Leningrad region, indicates the inviolability of the freshwater algae flora, favorable environmental conditions in water bodies and the absence of anthropogenic transformation of the studied territory.