scholarly journals Methods of redundant schemes and software for optimization of heat source structure

2019 ◽  
Vol 102 ◽  
pp. 02003 ◽  
Author(s):  
Olga A. Edeleva ◽  
Evgeny A. Barakhtenko ◽  
Dmitry V. Sokolov

The optimization of heat sources in populated areas is associated with the optimization of their structure. The optimization problem is of linear discrete nature and is hard to formalize [1]. The aim of the optimization is to identify the types, sites and mix of equipment of the heat sources. Moreover, this optimization problem is closely related to the scheme and parameter optimization since the equipment mix of heat sources and their connection to existing (newly constructed) consumers determine the heat network configuration. The emerging new trends in the technological development of heating systems require a significant correction of stating and solving typical technical and economic problems to design these systems, which, in turn, predetermines the transition to a new level of their methodological support [2]. The paper proposes a mathematical formulation of the problem of optimal development of heat sources and considers a methodological approach to solving it, including effective load distribution between heat sources, and calculation of the optimal heat network configuration, given the minimum environmental impact of heat sources.

2021 ◽  
pp. 1420326X2199462
Author(s):  
Stefano Ridolfi ◽  
Susanna Crescenzi ◽  
Fabiana Zeli ◽  
Stefano Perilli ◽  
Stefano Sfarra

This work is centred on an ancient Italian church. Since 2011, a restoration plan has been undertaken by following sequential phases. The methodological approach to restoration was guided by environmental monitoring campaigns. In particular, two thermo-hygrometric campaigns were carried out during the warm months of the years 2015 and 2016. The first set of measurements was executed during the restoration of facades and roofs, making it possible to reach even areas that are usually difficult to access. The second set was performed to evaluate the indoor thermo-hygrometric conditions following the work of the previous year. This was intended to assess their differences in variability, the influence of the outdoor environment and any real and perceived improvement. Results demonstrate that thermal images helped in identifying both the heat sources causing thermal discomforts and the good thermal capacity of masonries. Concerning the heat index (HI), the church showed an improvement in the trend of malaise perceived by people during the second summer period (∼2°C lower than 2015). Finally, in the last microclimate monitoring, the roof structure no longer acted as an amplifier for daily temperature excursions.


2016 ◽  
Vol 32 (6) ◽  
pp. 665-671 ◽  
Author(s):  
R. Kumar ◽  
S. Devi

AbstractThe main objective of the present paper is to analyze the effects of phase-lag on thick circular plate with heat sources in modified couple stress thermoelastic medium. The mathematical formulation is prepared for three-phase-lag heat conduction model subjected to prescribed normal heat flux along with stress free boundary. Laplace and Hankel transforms are used to deal the problem. The displacements, stresses and temperature change are obtained in the transformed domain. Numerical inversion technique has been used to obtain the solutions in the physical domain. The results obtained numerically for these quantities are presented graphically. Some particular cases are also discussed in the present problem.


Author(s):  
А. А. Чуйкина

Постановка задачи. Выбор наилучшего варианта трассы тепловой сети на начальном этапе проектирования является сложной многофакторной задачей, кроме того, ввиду отсутствия ряда необходимых конструктивных расчетов ее решение сопровождается ограниченностью набора исходных данных. Таким образом, становится актуальной разработка новой методики проектирования оптимальной трассы системы теплоснабжения, учитывающей качественные и количественные характеристики рассматриваемого объекта. Результаты. Разработана математическая модель обобщенного аддитивного векторного критерия оптимальности, учитывающая материалоемкость тепловой сети, ее надежность, время строительства, годовые тепловые потери, оборот теплоты и дисперсию температуры у потребителя. Предложен способ определения наилучшего варианта трассы тепловой сети на начальном этапе проектирования путем совместного решения задачи оптимизации методами векторной оптимизации и матричного обобщения. Отмечена целесообразность совместного применения методов попарного сравнения и векторной оптимизации при решении рассматриваемой задачи. Выводы. Важной характеристикой разработанной математической модели обобщенного критерия является возможность получения более точного решения рассматриваемой оптимизационной задачи при неравномерным распределении тепловой нагрузки посредством смещенной оценки дисперсии температуры у потребителей. Совместное применение методов матричного обобщения, попарного сравнения и векторной оптимизации позволяет повысить точность расчета при решении оптимизационной задачи выбора наилучшей трассы тепловой сети. Statement of the problem. Choosing the best option for the route of the thermal network at the initial stage of design is a complex multifactorial task, in addition, due to the lack of a number of necessary design calculations, its solution is accompanied by a limited set of initial data. Thus, it becomes relevant to develop a new methodology for designing the optimal route of the heat supply system, taking into account the qualitative and quantitative characteristics of the object under consideration. Results. A mathematical model of a generalized additive vector optimality criterion has been developed, taking into account the material consumption of the heat network, its reliability, construction time, annual thermal losses, heat turnover and temperature dispersion at the consumer. A method is proposed for determining the best option for the route of a thermal network at the initial design stage by jointly solving the optimization problem using vector optimization and matrix generalization methods. The expediency of the joint application of the methods of pairwise comparison and vector optimization in solving the problem under consideration is noted. Conclusions. An important characteristic of the developed mathematical model of the generalized criterion is the possibility of obtaining a more accurate solution to the optimization problem under consideration with an uneven distribution of the heat load by means of a biased estimate of the temperature variance among consumers. The combined application of the methods of matrix generalization, pairwise comparison and vector optimization can improve the accuracy of the calculation when solving the optimization problem of choosing the best route of the thermal network.


2019 ◽  
pp. 1-19
Author(s):  
Justin Yifu Lin ◽  
Célestin Monga

This chapter provides a methodological approach that draws lessons and insights from economic history and theory and uses empirics from economic analysis and policy practice. It starts with an observation of the increasingly globalized world economy in which technological development allows the use of factors of production in locations that maximize returns and utility, and countries gain mutually by trading with each other if their strategies focus on revealed and latent comparative advantage. By following carefully selected lead countries, latecomers can emulate the leader–follower, flying-geese pattern that has well served economies since the eighteenth century. The prospects for sustained and inclusive growth are even greater for low-income economies that enjoy the benefits of backwardness. The chapter advocates implementing viable strategies to capture new opportunities for industrialization, which can enable low-income economies to set forth on a dynamic path of structural change and lead to poverty reduction and prosperity.


Author(s):  
E. V. Yakovleva ◽  
◽  
A. R. Terentyeva ◽  

Ensuring the economic reliability of industrial enterprises in the modern conditions of technological dynamics is a necessary and indispensable condition for the successful development and functioning of the enterprise in the long term. The results of the study aimed at substantiating the methodological approach to the formation of the mechanism of economic reliability of technological development of industrial enterprises are presented, which determines the theoretical significance and novelty of the results are shown. The basis of the study is general scientific methods of classification, generalization, comparison, analysis


2019 ◽  
Vol 9 (1) ◽  
pp. 102-110
Author(s):  
Elyas Shivanian ◽  
Mahdi Keshtkar ◽  
Hamidreza Navidi

AbstractIn this paper, the problem of determining heat transfer from convecting-radiating fin of triangular and concave parabolic shapes is investigated.We consider one-dimensional, steady conduction in the fin and neglect radiative exchange between adjacent fins and between the fin and its primary surface. A novel intelligent computational approach is developed for searching the solution. In order to achieve this aim, the governing equation is transformed into an equivalent problem whose boundary conditions are such that they are convenient to apply reformed version of Chebyshev polynomials of the first kind. These Chebyshev polynomials based functions construct approximate series solution with unknown weights. The mathematical formulation of optimization problem consists of an unsupervised error which is minimized by tuning weights via interior point method. The trial approximate solution is validated by imposing tolerance constrained into optimization problem. Additionally, heat transfer rate and the fin efficiency are reported.


2021 ◽  
pp. 59-68
Author(s):  
Béla Cehla ◽  
Ferenc Ede Búzás ◽  
Sándor Kiss ◽  
István Szűcs ◽  
László Posta

Technological development makes it possible to simplify and accelerate decision-making processes by adequately processing and evaluating large volumes of data. Sub-data obtained from large data sets have a very important practical role in asset valuation, forecasting and valuing delineated or difficult-to-map areas, or in the context of portfolio management. Land valuation is a separate segment within asset valuation and it requires a specific methodological approach on behalf of evaluators. In this study, the authors compared the transaction data of arable land and the value of other land use categories. Based on empirical assessments, the authors developed proposals for the fast and cost-effective determination of the value of land use categories other than arable land - mainly meadows and pastures.


Author(s):  
Mikhail Osipenko ◽  

The joint bending of two Bernoulli–Euler’s beams is considered. Each beam has one end fixed and the other free. The beams have the different lengths and thicknesses. The long beam is loaded by the concentrated force. This beam is composite as it includes the internal joint. There is the frictionless unilateral contact between the beams. The elastic lines of the beams are to be found. This problem is reduced to finding of the density of forces of interaction between the beams and the constant that describes the unknown term in the displacement of the unrestrained part of the composite beam. The mathematical formulation of this contact problem is propounded. The density is assumed to be the sum of piecewise continuous function and delta-functions describing the concentrated forces. The uniqueness of the solution of the problem is proved and the analytical solution is constructed. Two possible contact patterns are found out. The former is contact at one point at the end of the short beam. The latter is contact at the same point and at one more point located at the unrestrained part of the composite beam. The coordinate of this point is the root of the cubic equation. The obtained analytical solution is used for the optimization of the structure. The optimization problem is to find the beams thicknesses that minimize the maximum stress for the given loading, beams lengths and the overall deflection. This problem is solved numerically for some values of the given parameters. The hypothesis of the equal-stressed optimum structure is set up on the basis of the numerical results. This hypothesis enables to construct the analytical solution of the optimization problem.


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