scholarly journals Comparative analysis of computer programs for hydraulic calculation of steam-water mixture in pipelines

2021 ◽  
Vol 895 (1) ◽  
pp. 012011
Author(s):  
A Chermoshentseva ◽  
A Shulyupin

Abstract In the practice of developing geothermal fields, it is necessary to forecast the flow parameters of the well and the pressure drop in the pipeline and need to decide on the optimal design for stable operation of the pipeline. At domestic facilities of geothermal energy, the hydraulic calculation of the steam-water mixture pipelines was carried out using the computer program MODEL developed by the authors of this work. New challenges and the emergence of stability theory led to the creation of the mathematical model SWIP (Steam-Water Inclining Pipeline). This paper presents a comparative analysis of two options for implementing the new model.

Author(s):  
А.А. Чермошенцева ◽  
А.Н. Шулюпин

В практике освоения геотермальных месторождений возникает необходимость нахождение взаимосвязи между параметрами потока. При транспортировке пароводяной смеси требуется определение условий, обеспечивающих стабильную работу трубопровода. На отечественных объектах геотермальной энергетики гидравлический расчет трубопроводов пароводяной смеси проводился с использованием компьютерной программы MODEL, разработанной авторами данной работы. Новые вызовы и появление теории устойчивости привели к созданию математической модели SWIP (Steam-Water Inclining Pipeline). В данной статье представлены этапы разработки авторами новой модели, отвечающей современным требованиям In the practice of developing geothermal fields, there is a need to find the dependence between the flow parameters. When transporting a steam-water mixture, it is necessary to determine the conditions that ensure the stability in the pipeline. At domestic geothermal energy, the hydraulic calculation of steam-water mixture pipelines was carried out using the computer program MODEL created by the authors of this work. New challenges and the emergence of the theory of stability led to the creation of a mathematical model SWIP (Stream-Water Inclining Pipeline). This article presents the stages of creating a new model by the authors that meets modern requirements.


2020 ◽  
Vol 192 ◽  
pp. 04004
Author(s):  
Aleksandr Shulyupin ◽  
Alla Chermoshentseva ◽  
Natalia Varlamova

A new mathematical model of steam-water flow in a pipeline, which takes into account the gravitational effect and satisfies new challenges in the development of geothermal fields with two-phase transportation of the heat carrier is presented. Taking into account the gravitational effect in the upstream flows, a method based on the “drift model”, which determines the steam velocity averaged over the crosssection was used. A similar method is proposed for downstream flows, but it determines the water velocity averaged over the cross-section. In this case, analogs of empirical coefficients were used. These coefficients determined from the condition of equality of parameters calculated using different approaches in a horizontal flow. The model was verified, which showed positive results. The proposed model significantly expands the possibilities of hydraulic calculation of steam-water mixture pipelines in geothermal fields.


Author(s):  
А.Н. Шулюпин ◽  
А.А. Чермошенцева ◽  
Н.Н. Варламова

Исследуются случаи существования неустойчивости потока, вызванной влиянием гравитационных сил в трубопроводах пароводяной смеси на геотермальных месторождениях. Представлена новая разработанная авторами математическая модель пароводяного течения, учитывающая гравитационный эффект и удовлетворяющая новым вызовам при освоении геотермальных месторождений с двухфазной транспортировкой теплоносителя. Показано влияние наклона трубопровода и рельефа трассы на гравитационную устойчивость течения. Даны рекомендации по гидравлическому расчету и строительству трубопроводов пароводяной смеси. Cases of flow instability caused by the influence of gravitational forces in pipelines of steam-water mixture in geothermal fields are investigated. A new mathematical model of the steam-water flow was developed by authors, taking into account the gravitational effect and satisfying new requirements in the development of geothermal deposits with two-phase heat carrier transportation. The influence of the pipeline incline at the gravitational stability of the flow is shown. Recommendations on hydraulic calculation and construction of steamwater mixture pipelines are given.


2021 ◽  
Vol 9 (1) ◽  
pp. 91-100
Author(s):  
Serhii Tsymbaliuk

The purpose of the article is to study the experience of developed countries in the regulation of sports and health in order to stimulate its development and adaptation to new challenges and threats. In the course of the research the methods of theoretical and comparative analysis were used to reveal the peculiarities of the American and European models of sports and health man-agement; statistical and graphical - to determine the economic role and trends in the sports and health industry in the world, the impact of the pandemic on income from sports. The article develops organizational and economic approaches to intensify the development of sports and recreation. Certain features of organizational models of management, sports legislation, financ-ing, possible tools to stimulate the development of sports and health in the developed world form a scientific basis for substantiating ways to intensify this area.


2021 ◽  
Vol 14(63) (1) ◽  
pp. 129-136
Author(s):  
Kateryna VASYLKOVSKA ◽  
Oleksii VASYLKOVSKYI ◽  
Svitlana POPOVA ◽  
Valentyna Malakhovska

"The production and yield of grain crops in Ukraine from 2000 to 2019 was analysed in the article. The comparative analysis of gross harvest and export of grain during these years was carried out and the dependence of exports on gross harvest and its share was determined. The results point out that the export of grain crops has increased over the years under research, which indicates Ukraine’s significant export potential. Thus, leaving for the needs of the country from 16.0 to 36.6 million tons of grain (on average, 25.9 million tons), Ukrainian farmers export an average of 40.7% of the crop. During the period from 2000 to 2019, the gross harvest of grains in the country averaged 48.4 million tons resulting in the annual potential share of exports of at least 22.4 million tons. It was also found that the increase in the share of exports was made possible by a qualitative change in yield, which was due to the changes in crop growing technology. However, with global warming and climate change, new challenges for agricultural producers are emerging. The recommendations were given in order to improve the crop growing technology that will allow to overcome these challenges, further increase yields and Ukraine's export potential. "


Author(s):  
Dezhong Li ◽  
Ning Mei ◽  
Jian Su

The purpose of this paper is to study flow behavior in a vibrating pipe on offshore platform. The mathematical model of unsteady, incompressible, viscous flow in a vibrating pipe is established according to the basic theory of oscillating fluid mechanics. The governing equations of flow are decomposed into a system for steady flow and another for flow oscillation, with the equations of the differential coefficients of flow parameters solved by using the parametric polynomial method. Velocity and pressure distributions are obtained for different flow conditions. Numerical results indicate that the flow behavior in the vibrating pipe on offshore platform is strongly affected by fluid properties and the pipe structure. A good agreement is obtained when comparing the results with the variational solution in constant cross-section, which shows that the method proposed in this work is effective for studying flow behavior in a vibrating pipe on offshore platform.


2011 ◽  
Vol 34 (4) ◽  
pp. 422-435 ◽  
Author(s):  
Jerzy Baranowski ◽  
Paweł Piątek

Control of active magnetic bearings is an important area of research. The laboratory magnetic levitation system can be interpreted as a model of a single axis of bearings and is a useful testbed for control algorithms. The mathematical model of this system is highly non-linear and requires careful analysis and identification. The system is observable from position measurements as long as the electromagnet is powered as shown during the research. Practically measurable signals are the position and the coil current. The velocity that is necessary for any stabilizing control usually is obtained by numerical differentiation of the position. A more sophisticated approach is to estimate the velocity with an observer. Efficient observer types for this system are high-gain and non-linear reduced observers. The velocity estimated by an observer can be effectively used instead of a derivative in PID control of the position. Such an approach substantially improves control quality and extends the range of system’s stable operation. Even greater improvement is introduced by the addition of the non-linear feedforward to the control structure. The best results, provided the model parameters are correctly identified, are obtained with a control system consisting of the PID controller, the high-gain observer and the non-linear feedforward.


2021 ◽  
Vol 2021 ◽  
pp. 1-23
Author(s):  
Karpenko Vasily Nikolaevich ◽  
Yuriy Starodub ◽  
Andrii Havrys

In the article, investigation is given of the developed mathematical models of nonequilibrium in time and distributed in space thermodynamic state of Earth’s matter from its center to its surface depending on the cases of the presence and absence of an internal source of thermal energy concentrated in the center of mass taking into account known geophysical data about the nucleus, mantle, lithosphere and atmosphere, and endogenous and exogenous heat fluxes. The objects of research are as follows: mathematical models of geothermal energy of the Earth, its internal source, and heat balance of endogenous and exogenous heat fluxes on the Earth’s surface. Research methods used are as follows: thermometry in deep wells, ground and remote sensing of heat fluxes of the Earth and the planets of the Solar System, mathematical modeling of heat exchange and thermoelastic processes from compression of Earth’s matter by gravitational field energy information and classical physical and mathematical methods, and computer modeling. The aim of research: in computer modeling to provide new mathematical models that determine the geophysical parameters of geothermal energy, which are aimed on solving problems of energy, environmental and economic security of society, using modern technical means of calculating ground and remote sensing data development of geothermal resources, and regulation of the heat balance of the ecosystem, namely: (i) study of the geological structure of the lithosphere to a depth of 10 km by remote sensing to determine the physical parameters of its layers more accurately than ground methods; (ii) development of projects of geothermal power plants on the basis of single isolated wells of a given depth with a capacity of up to 2 ÷ 3 mW of electricity on continents of the globe; (iii) real-time monitoring and forecasting of the temperature field of the atmosphere according to its physical and chemical composition. The novelty of the obtained research results: (i) developed the mathematical model of the physical process of origin and distribution in the bowels of the density of geothermal energy of the Earth from the surface to its center, which is the density of internal energy of an elementary geological object, and which increases when approaching the center of the planet; (ii) developed the mathematical model of the thermal energy source of infrared (IR) waves of the elementary geophysical object of the Earth’s interior depending on the depth of its occurrence, which allows to determine the stable generation of geothermal energy by rocks in a deep well for extraction and conversion into electricity and to study the geological structure and physical properties of the Earth’s interior; (iii) the mathematical model of heat exchange between the layers of the Earth’s subsoil with the thermal energy of infrared waves according to the laws of Fourier thermal conductivity and Stefan–Boltzmann heat transfer, which together with the geothermal energy source model allows to determine a thermal capacity of rocks in a deep well; (iv) developed the mathematical model of stable action of a source of thermal energy in the center of mass of the Earth, in the absence of which it is hard to explain the power of its endogenous infrared heat flux, parameters of geothermal energy distribution in the Earth, and the current thermodynamic state of the atmosphere, and the change in temperature of which depends on the thermophysical parameters of the physical-chemical composition of the atmosphere more than on changes in the thermal activity of the Sun; (v) determination of new numerical values: thermophysical parameters of the Earth’s interior; kinetic, potential and own gravitational energy of the Earth and own gravitational energy of the planets of the Solar System.


Author(s):  
Leonardo César Freitas ◽  
Olexiy Shynkarenko

The work is focused on the performance estimation and control of a cold flow inside a ramjet test engine, which initially operates without combustion, preparing the flow for the main propulsive phase. To achieve this objective, a “connected pipe” test bench was assembled. Flow management was performed using the control valve that allows regulating pressure and air mass flow rate in the engine according to its flight conditions through sensors installed at relevant positions. The proportional, integral and derivative (PID) parameters for the flow control algorithm were studied in order to guarantee the stable operation of the engine and correspondence of the flow parameters to predicted ones by the analytical modeling. Experimental results were validated by the numerical and analytical compressible flow models.


Sign in / Sign up

Export Citation Format

Share Document