Mathematical models and methods for analyzing flow properties in hydraulic circuits with closed circulation circuits

The article is devoted to the problems of calculating the distribution of flow quality parameters over the elements of the hydraulic system. The main attention is paid to the problem of such a calculation in the presence of closed circulation circuits in the system, when traditional methods and algorithms become ineffective. Mathematical models of the distribution of quality parameters are given, the results of the analysis of their properties in the presence of closed circulation circuits are presented. Against the background of the analysis of the applicability of general mathematical methods for solving the problem, two new methods are proposed based on the special properties of this problem - the “iterative topological” algorithm and the “algebraic-topological” method. Both methods are universal and provide a solution in the presence of closed circulation loops, and in their absence they coincide with the traditional “topological” algorithm

Optimization of hydraulic modes of single-source tree-like heat networks

The article deals with the problem of optimizing the hydraulic modes of radial heat supply systems with a single heat source and pumping stations. The features of the problem under consideration are the presence of several target functions and a fixed flow distribution. The topology of the networks under consideration allows using the equivalent branching methods of branches connected in parallel and in series to reduce the design schemes to single equivalent branches. To solve this problem, the original method proposed by the authors earlier is adapted. The proposed method was tested on an aggregated scheme of a real heat supply system. Computational experiments have shown the performance and computational efficiency compared with the methods proposed earlier

Modern Experience in Dynamic States Simulation of Pipeline Systems and the Possibility of its Application to Solving Identification Problems

The effectiveness of solving the problems of development, reconstruction and control of pipeline systems is directly related to the level of application of methods for mathematical modeling and computer technology, which cannot be provided in isolation from the problems of reliability of information about their actual characteristics and parameters, as well as the degree of adequacy of used models. These problems constitute the content of identification tasks. The trend of transition to intelligent pipeline systems requires consideration of their control processes in real time, and hence the consideration of identification problems as passive identification problems based on the results of dynamic measurement data. The article provides an analysis of the existing experience in the field of dynamic states modeling of pipeline systems of various types and purposes, as well as mathematical formulations of the identification problem depending on the degree of parametric and state nonstationarity of systems, on the method and rate of data acquisition

Information and computing spaces integration for operating enterprises of pipeline systems using “ANGARA” computer technology★

The article describes the informatization level of enterprises operating pipeline networks. Existing problems are presented. These problems are related to the fragmentation of information systems and the inability to provide information support for decision-making on the management of the development and operation of pipeline systems. An overview of the most high-usage used software for automate the activities of enterprises is given. The need to create a common information space of an enterprise and the opportunities it provides is shown. A brief description of the information-computer environment “ANGARA” and the technology of organizing a common information space on its basis is given. The experience of practical application of the information-computer environment “ANGARA” for creating the common information space of the Municipal Unitary Enterprise “Vodocanal” in Irkutsk is cited. On the diagram of the organizational structure of the enterprise the workplaces with access to a common information is showed

Quantitative assessment of the identifiability of pipeline systems★The research was carried out within the project III.17.4.3 of the Fundamental research program of SB RAS (AAAA-A17-117030310437-4)

The article is devoted to the issues of quantitative assessment of the identifiability of the pipeline systems (heat, water, gas supply systems etc.). Identifiability is first considered as a complex property, including such particular properties as observability and parametric identifiability. A brief description of the topic relevance and a review of available development in this sphere allow giving the structuring of identifiability analysis problems. The technique of differentiate quantitative analysis of this property is disclosed. It based on the use of analytical expressions for covariance matrices of parameters. New concepts of experimental matrices, parametric identifiability and observability of pipeline systems are introduced. Analytic expressions for these matrices are given. The substantiation of the integral indicators of the pipeline systems identifiability is presented, including the covariance matrix determinant for the estimated parameters and the relative variance of the prediction for non-measurable state parameters. The analytical interrelation of these indicators is opened. These indicators can be accepted in a role of criteria at decision of synthesis problems for optimal measurements composition

Quantitative assessment of the identifiability of pipeline systems

The article is devoted to the issues of quantitative assessment of the identifiability of the pipeline systems (heat, water, gas supply systems etc.). Identifiability is first considered as a complex property, including such particular properties as observability and parametric identifiability. A brief description of the topic relevance and a review of available development in this sphere allow giving the structuring of identifiability analysis problems. The technique of differentiate quantitative analysis of this property is disclosed. It based on the use of analytical expressions for covariance matrices of parameters. New concepts of experimental matrices, parametric identifiability and observability of pipeline systems are introduced. Analytic expressions for these matrices are given. The substantiation of the integral indicators of the pipeline systems identifiability is presented, including the covariance matrix determinant for the estimated parameters and the relative variance of the prediction for non-measurable state parameters. The analytical interrelation of these indicators is opened. These indicators can be accepted in a role of criteria at decision of synthesis problems for optimal measurements composition