scholarly journals Shape and operation optimization of a thick-walled power boiler component

2018 ◽  
Vol 240 ◽  
pp. 05006
Author(s):  
Piotr Duda ◽  
Mirosław W. Mrzygłód
Keyword(s):  
Stress Constraints ◽  
Practical Significance ◽  
Operation Optimization ◽  
Optimization Constraints ◽  
New Methods ◽  
Heating And Cooling ◽  
Unit Energy ◽  
Start Up ◽  
Load Regime ◽  
Power Boiler

The aim of this article is the proposition of a two-stage optimization of power boiler components subjected to transient thermo-mechanical loads. As the basis of transient load regime, the TRD 301 regulations are used. In the first stage of an investigation, the genetic algorithms are used to determine the optimal shape of the structure. As optimization constraints, the maximum total stresses in the whole cycle are assumed. In the next stage, the method for the start-up and shut-down operation optimization is shown. The problem is defined to minimize the time of start-up and shut-down processes with allowable stress constraints according to TRD regulations. These new methods are of high practical significance and can be implemented throughout the industry, wherever heating and cooling processes take place. The obtained optimization results translate directly into the power unit energy effectiveness because the shut-down and start-up losses are reduced.

scholarly journals A new method for determining allowable medium temperature during transient operation of thick-walled elements in a supercritical power plant

2010 ◽  
Vol 31 (3) ◽  
pp. 55-72
Author(s):  
Piotr Duda ◽  
Dariusz Rząsa
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
New Method ◽  
Optimum Operating ◽  
Transient Operation ◽  
Medium Temperature ◽  
Heating And Cooling ◽  
Optimum Parameters ◽  
Start Up ◽  
Working Parameters

A new method for determining allowable medium temperature during transient operation of thick-walled elements in a supercritical power plantConstruction elements of supercritical power plants are subjected to high working pressures and high temperatures while operating. Under these conditions high stresses in the construction are created. In order to operate safely, it is important to monitor stresses, especially during start-up and shut-down processes. The maximum stresses in the construction elements should not exceed the allowable stress limit. The goal is to find optimum operating parameters that can assure safe heating and cooling processes [1-5]. The optimum parameters should guarantee that the allowable stresses are not exceeded and the entire process is conducted in the shortest time. In this work new numerical method for determining optimum working parameters is presented. Based on these parameters heating operations were conducted. Stresses were monitored during the entire processes. The results obtained were compared with the German boiler regulations - Technische Regeln für Dampfkessel 301.

Application of Modern Information Technologies on Growth Model of Poplar

2014 ◽  
Vol 543-547 ◽  
pp. 1807-1810
Author(s):  
Jian Wei Song ◽  
Shuo Mei Wu ◽  
Jie Zhu ◽  
Xu Ning Liu
Keyword(s):  
Information Technology ◽  
Growth Model ◽  
Information Technologies ◽  
Production Management ◽  
Prediction Models ◽  
Practical Significance ◽  
Relational Models ◽  
New Methods ◽  
Growth Character ◽  
Poplar Growth

In recent years the research on structure and efficiency mode of farmland shelterbelt are more, while the prediction models of the poplar are much less. The growth model is based on poplar growth and management, the development of information technology provides new methods for the research and evaluation of poplar growth model. All kinds of information technology are used to extract growth character parameters of poplar, and neural network and expert system is used to establish the relational models of the character parameters and production management of poplar, these models are used to provide the basis for the cultivation of poplar growth and management, which have important theory value and practical significance.

scholarly journals DYNAMIC LOAD REDUCTION DEVICE IN MACHINE DRIVE WITH SPRING AND SELECTION OF ITS PARAMETERS

2021 ◽  
Vol 297 (3) ◽  
pp. 87-93
Author(s):  
Yuri Kovalyov ◽  
◽  
Sergey Pleshko ◽  
Evgeny Lopukhov ◽  
◽  
...  
Keyword(s):  
Dynamic Loads ◽  
Practical Significance ◽  
Process Equipment ◽  
Technological Equipment ◽  
Light Industry ◽  
Torsion Spring ◽  
Operating Modes ◽  
Start Up ◽  
Dynamic Loadings ◽  
Selection Of

The peculiarity of the technological equipment of light industry is the significant dynamic loads that occur during unstable operating modes and is one of the main reasons for reducing the reliability and durability of its operation. The problem of increasing the reliability and durability of their work by reducing the dynamic loads is relevant, because the known means of reducing the dynamic loads in the drive of machines can not always be used in light industry machines. Therefore, when designing light industry equipment, first of all, attention should be paid to reducing the dynamic loads in the drive and preventing accidents. The paper considers the feasibility of using a device with a torsion spring to reduce the dynamic loads in the drive of process equipment, check its performance and develop a method for selecting rational parameters. In the course of work modern methods of researches of mechanical systems are used for the purpose of an estimation of expediency of use of the device with a torsion spring for reduction of starting dynamic loadings in the drive of machine. On the basis of the analysis of features of work of the technological equipment of light industry the expediency of use in the drive of cars of the gear safety coupling with a torsion spring is established. A new design of the device is proposed to reduce the dynamic loads that occur during machine start-up. Unlike the known devices, the proposed device is made in the form of a toothed safety clutch with a torsion spring, which simplifies its design and increases efficiency. The use of a cylindrical torsion spring as an elastic element, which connects the half-clutch to the flange on which the satellite gears are mounted, prevents overloading of the drive and the choice of rational rigidity of the device depending on the change of operation, which increases its durability and expands performance. The method of checking the efficiency of the device for reducing dynamic loads and selecting its rational parameters is presented. The scientific novelty is the development of scientific bases and engineering methods of designing devices to reduce dynamic loads in the drive of technological equipment. The practical significance lies in the development of a new design of the device to reduce the dynamic loads in the drive of machines and the engineering method of choosing its rational parameters.

scholarly journals Public administration strategy of healthcare system for seniors

2021 ◽  
Vol 5 (3) ◽  
pp. 630-638
Author(s):  
Nina Grigorievna Shamshurina ◽  
Victor Ivanovich Shamshurin ◽  
Yuliya Aleksandrovna Laamarti ◽  
Lyubov Nikolaevna Ryabchikova ◽  
Alexander Alexandrovich Nikolaev ◽  
...  
Keyword(s):  
Public Administration ◽  
Healthcare System ◽  
The Elderly ◽  
Practical Significance ◽  
Philosophical Study ◽  
Investment Fund ◽  
Model Of Care ◽  
Social Stratum ◽  
Economic Methods ◽  
Start Up

The goal of the study is to restructure society’s attitude toward the needs of the elderly. The article addresses the methodology of state social policy and possible innovations in funding and economic methods for public administration in the healthcare system for seniors. The novelty of the work is ensured by the concept of managed older age and a start-up proposal to create the State Direct Investment Fund “Senior Generation” functioning as an entity responsible for the development of the organizational foundations for gerontology and geriatrics services. The practical significance of the study lies in the optimization of the modern management model of care for the older generation and a philosophical study of age as a potential in management in both individual and societal regards. This strategy can serve as a basis for public administration of the healthcare system for the elderly accounting for the diversity of seniors as a social stratum.

scholarly journals DETERMINATION OF PHYSICAL AND TECHNOLOGICAL PROPERTIES OF QUINO GRAIN - THE MAIN STAGES OF JUSTIFICATION OF STORAGE AND PROCESSING TECHNOLOGY

2021 ◽  
Vol 21 (1) ◽  
pp. 4-8
Author(s):  
L. Valevskaya ◽  
O. Sokolovskaya
Keyword(s):  
Fatty Acid ◽  
Acid Composition ◽  
Physical And Mechanical Properties ◽  
Essential Amino Acids ◽  
Practical Significance ◽  
Soil Conditions ◽  
Technological Properties ◽  
Animal Products ◽  
Heating And Cooling ◽  
Air Supply

The work is devoted to determining the physical and technological properties of quinoa grain. Quinoa is an unconventional crop for Ukraine, but experiments on its cultivation have been successfully completed in the Sumy region. Due to its unique chemical composition, quinoa is used in dietary and functional products.Quinoa contains about 20% protein, which makes it an excellent dietary supplement for people who do not eat animal products. The amino acid composition of quinoa proteins is very balanced and is characterized by a high content of such essential amino acids. Feature of the fatty acid composition of quinoa. it has a high content of polyunsaturated fatty acids, including linolenic fatty acid and linoleic, which belongs to the acids ω-3 and ω-6 fatty acids.Due to the growing popularity of quinoa and its suitability for cultivation in our climatic and soil conditions, it is important to develop the technology of its storage and processing. One of the main stages of substantiation of the choice of technology for storage and processing of quinoa grain is to determine its physical and technological properties.Physical and technological properties of grain mass are determined by a large number of indicators.Determination of physical and technological properties of quinoa grain was performed for three types of quinoa: red, black and white. In determining the physical and mechanical properties were used methods approved by the relevant standards, or used in research and recommended in the relevant literature.We have identified the following basic physical and technological properties: geometric characteristics, nature, weight of 1000 grains, duty cycle, packing density, air supply, angle of natural slope, coefficient of internal friction, coefficient of external friction. Numerical values of these indicators for each type of quinoa are determined.Knowledge of the physical and technological properties of the grain mass to solve a large number of applied problems that have practical significance. and play an important role in the processes of moistening, heating and cooling of grain. A thorough study of physical and technological properties can provide optimal conditions for storage of seeds without compromising their quality. The obtained data can be used for selection of modes of cleaning, drying and active ventilation.

scholarly journals Academic language as an object of teaching foreign languages to philology students

2021 ◽  
Vol 5 (S4) ◽  
pp. 657-676
Author(s):  
Oksana V. Asadchykh ◽  
Liudmyla H. Smovzhenko ◽  
Iryna V. Kindras ◽  
Ihor I. Romanov ◽  
Tetiana S. Pereloma
Keyword(s):  
Foreign Language ◽  
Academic Language ◽  
Spoken Language ◽  
Foreign Languages ◽  
Practical Significance ◽  
Visual Images ◽  
New Methods ◽  
Language Research ◽  
Intercultural Exchange ◽  
Knowledge Communication

In the modern socio-educational environment, which is developed through intercultural exchange and the implementation of new methods of spreading knowledge, communication in the student environment is based on the exchange of visual images and philological units. For students of the philological direction, communication with foreign language communicants is determined by the possibility of improving the function of conversation, perception of cultural characteristics and obtaining new images. Of relevance is the perception of not only spoken language by students, but also of the academically correct lexical group. The novelty of the study is determined by the fact that academic language is often perceived as a kind of anachronism, as something insufficient to expand linguistic competence. The study proves that the readiness of students to implement the provisions of academic language is possible not only culturally, but is also achievable by pedagogical methods. The study demonstrates that the implementation of the extended learning format is achieved through the techniques of linguistic learning. The practical significance of the study is that the perception of academic language will allow students of the philological direction to implement their skills in various social spheres, which may require historical language research and be predominantly fundamental.

Alliances of maritime liner container carriers: the essence of this phenomenon and its practical significance

2021 ◽  
pp. 44-51
Author(s):  
A. G. Neiogov ◽  
A. Ouami
Keyword(s):  
Foreign Trade ◽  
International Law ◽  
Negative Influence ◽  
General Information ◽  
Practical Significance ◽  
Effective Control ◽  
Maritime Transport ◽  
New Methods ◽  
And Control ◽  
International Initiative

Alliances are a key element of modern liner shipping. This article introduces alliances as a new form of consolidation of container lines and offers general information about their activity. The authors examined numerous reliable sources to evaluate different factors which influence the results of shipping lines' participation in global alliances. The authors offer their appraisal of alliances based on research as well as their own experience in shipping. They consider the liner market as an oligopoly of a few companies, which are closely intertwined with the world’s largest corporations and where international law has been substituted with a control by regulators from some of the most powerful countries in the liner trade. This system allows the business of some customers to be protected, while applying limitations on others. Undoubtedly, the alliances have an influence on Russian foreign trade. In summary, the authors believe that the Russian authorities should carefully investigate and control the service of global carriers and alliances. The chief aim of effective control is the free participation of Russian companies in foreign trade, which is not possible without due support of maritime transport. The alliances are truly global entities. They combine both traditional and new methods, including cutting-edge capabilities of information and digital technologies. To prevent a negative influence of the oligopoly, a new international initiative to regulate the alliances as was done with shipping conferences is highly welcomed by the authors.

scholarly journals Determination of allowable fluid temperature during start-up operation of outlet header under the assumption of constant and temperature-dependent material properties

2013 ◽  
Vol 34 (3) ◽  
pp. 3-14
Author(s):  
Dariusz Rząsa ◽  
Piotr Duda
Keyword(s):  
Power Plants ◽  
Operation Time ◽  
Optimum Operating ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Temperature Dependent ◽  
Allowable Limit ◽  
Heating And Cooling ◽  
Start Up ◽  
Operation Cycle

Abstract Modern supercritical power plants operate at very high temperatures and pressures. Thus the construction elements are subjected to both high thermal and mechanical loads. As a result high stresses in those components are created. In order to operate safely, it is important to monitor stresses, especially during start-up and shut-down processes. The maximum stresses in the construction elements should not exceed the allowable stresses that are defined according to boiler regulations. It is important to find optimum operating parameters, that can assure safe heating and cooling processes. The optimum parameters define temperature and pressure histories that can keep the highest stresses within allowable limit and reduce operation time as much as possible. In this paper a new numerical method for determining optimum working fluid parameters is presented. In this method, properties of steel can be assumed as constant or temperature dependent. The constant value is taken usually at the average temperature of the operation cycle. For both cases optimal parameters are determined. Based on these parameters start-up operations for both cases are conducted. During entire processes stresses in the heated element are monitored. The results obtained are compared with German boiler regulations - Technische Regeln fur Dampfkessel 301.

scholarly journals A Framework for Design and Operation Optimization for Utilizing Low-Grade Industrial Waste Heat in District Heating and Cooling

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2190
Author(s):  
Lingwei Zhang ◽  
Yufei Wang ◽  
Xiao Feng
Keyword(s):  
Industrial Waste ◽  
Energy Demand ◽  
Heat Recovery ◽  
Waste Heat ◽  
District Heating ◽  
Mixed Integer ◽  
Low Grade ◽  
Operation Optimization ◽  
Heating And Cooling ◽  
Industrial Waste Heat

In the process industry, a large amount of low-grade waste heat is discharged into the environment. Furthermore, district heating and cooling systems require considerable low-grade energy. The integration of the two systems has great significance for energy saving. Because the energy demand of consumers varies in periods, the design and operation of an industrial waste heat recovery system need to match with the fluctuations of district energy demand. However, the impact of the periodic changes on the integration schemes are not considered enough in existing research. In this study, a framework method for solving above problem is proposed. Industrial waste heat was integrated with a district heating and cooling system through a heat recovery loop. A three-step mathematical programming method was used in design and operation optimization for multiperiod integration. A case study was conducted, and the results show that the multiperiod optimization method can bring significant benefits to the system. By solving the mixed integer nonlinear programming model, the optimal operation plans of the integration in different periods can be obtained.

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