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UDC 628.144:532.542
Yepifanov S. P., Zorkaltsev V. I.
The task of flow distribution with nonfixed junction points of consumption
Summary
A model of flow distribution in the water supply and distribution system with nonfixed junction points of consumption is considered. The model provides for more detailed characteristics of flow distribution both in normal conditions and emergency mode. The suggested junction point flow rate – water head ratios provide for the actual consumption amounts at the consumers’. The flow distribution algorithm in the form of nonlinear algebraic equation system is presented supported with the demonstration of differences in the results of calculating flow distribution with both fixed and nonfixed junction points of consumption.
Key words
water supply , water leaks , pipeline system , flow distribution , nonfixed junction point of consumption , hydraulic head

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UDC 628.14:519.6
Novitskii N. N., Mikhailovskii E. A.
ISIGR Innovative software suite for the simulation of the operation modes of water supply systems
Summary
Energy and resource–saving reserves in the systems of water supply and distribution can be largely deployed by rational organization of the hydraulic modes of their operation with the use of advanced methods of mathematical and computer simulation. The description of a programming and computing suite that provides for the opportunity of using remotely the efficient methods of calculating the operation modes of water supply and distribution systems is presented. The principles of the suite implementation allow any number of users to make calculations anytime and anywhere provided the access to global Internet and standard Web browser is available. The suite underlying technologies are stated as well as its user options and computational performance. The results of pilot studies of the programming and computing suite are quoted. The application can be used in different branches (power economy, housing and public utilities, construction etc.) and fields of activities (engineering, operation, studies and education). It can be also useful for the experts of different levels – engineers, research workers, postgraduates, student, etc.
Key words
hydraulic condition , water supply and water distribution system , flow distribution , programming and computing suite , mathematical and computer simulation

DOI 10.35776/MNP.2020.05.03 UDC 004.94+519.6:656.56+699.814
Mikhailovskii E. A.
Modeling hydraulic modes of firefighting water system operations in the Internet
Summary
Basic fire protection of industrial and storage facilities, shopping and entertainment centers and other objects is made up of automated firefighting installations, internal fire water pipeline and water curtains. The analysis of the results of hydraulic calculations performed while designing these systems provides for selecting the required equipment composition, evaluating the operation of the systems in different modes etc. Hydraulic calculations are carried out, as a rule, using hand calculation, or a partially automated process. Algorithms are also used that implement numerical modeling procedures involving offtheshelf software that simplifies compiling a system of equations with the formation of a calculation model from nodes and connecting paths. The software available in the domestic market is either not effective or very expensive, and requires user training. Substantive and mathematical statement of the flow distribution problem with variable nodal flow rates for a random pipeline system including fire protection, is presented. The corresponding modification of the nodal pressure method is given that takes into account the dependence of the flow through the nozzle (sprinkler, fire branch, etc.) on the pressure (head) upstream of it. This task and other ones can be solved using «ISIGR» programming and computing suite developed at the Institute of Energy Systems named after L. A. Melent’ev of the Siberian Branch of the Russian Academy of Sciences. The software is designed for modeling in the Internet the hydraulic modes of the ring systems of water, gas supply and firefighting. The software has an effective, convenient, userfriendly graphical interface that provides for drawing a network layout with minimal effort, performing hydraulic calculations, and interpreting the results in graphical or tabular style.
Key words
water supply , flow distribution , water curtain , mathematical and computer simulation , internal fire water pipeline , automated firefighting system
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UDC 628.144:532.542
Baranchikova N. I., Yepifanov S. P., Zorkaltsev V. I., Kurtin A. V., Obuzdin S. Iu.
Flow distribution in water supply and distribution systems with automatic pressure regulators
Summary
The task of flow distribution in general pipeline systems including the systems of water supply and distribution with automatic pressure regulators is considered. To improve the reliability of the system operation pressure regulators are often installed «downstream» (reducing valves) and «upstream» (tank release valves). Pressure regulators manufactured by Bermad have been installed in the water distribution networks of Irkutsk; that provided for reducing and stabilizing the pressure in some zones. However zones exist that are supplied from several water pipelines with different pressure at the connection points, therefore sometimes complete closing of some regulators occurs (more often with small diameters) or flow reversal is possible, and the water flows through the regulator in the opposite direction. In this case the regulator fails to fulfill its function. Mathematical modeling of such situations is very important because it is them which significantly complicate the operation of the water supply and distribution systems. Mathematical models of automatic «upstream» and «downstream» pressure and pressure drop regulators are suggested with account of their version: normally open or normally closed. The mathematical formulation of the problem of flow distribution in the systems of water supply and distribution with pressure regulators is presented. The critical for the practice task of flow distribution in the pipelines with automatic regulators has been solved for the setting that describes different scenarios of the automatic regulators operation. A simple and efficient method of solving the set task of flow distribution that does not require derivation and has rapid enough convergence is suggested. On the basis of the numerical experiments it is fair to assume that the number of iterations moderately depends on the dimension of the problem (number of nodes and semicircular arcs), considerably depends on spread of hydraulic resistance values and to a lesser extent – node selection.
Key words
pressure , mathematical model , pipeline system , flow distribution , hydraulic head , systems of water supply and distribution

