A mathematical model of the water decarbonization processes in atmospheric deaerators is proposed to calculate the thermal decomposition degree of hydrocarbonates in a deaerator, pH of a deaerated water sample, and the mass concentration of free carbonic acid in it on a carbon dioxide basis. The mathematical description of these processes is based on the deaeration tank water flow model implemented in the specialized software suite for the calculation of three-dimensional liquid flows, where a real water flow is a set of parallel small plug-flow reactors, and the rate constant of the reaction representing a generalized model of the thermal decomposition of hydrocarbonates with consideration for its chemical and diffusion stages is identified by experimental data. Based on the results of experimental studies performed on deaerators of different designs with and without steam bubbling in their tanks, an empirical support of this model has been developed in the form of recommended reaction order and rate constant values selected depending on the overall alkalinity of water fed into a deaerator. A self-contained mathematical description of the water decarbonization processes in deaerators has been obtained. The proposed model precision has been proven to agree with the specified metrological characteristics of the potentiometric and alkalimetric methods for measuring pH and the free carbonic acid concentration in water. This allows us to recommend the obtained model for the solution of practical problems of forming a specified amount of deaerated water via the selection of the structural and regime parameters of deaerators during their design and regime adjustment.

Modeling the water decarbonization processes in atmospheric deaerators

The lack of reliable information on the status of fixed assets of medical institutions located in rural areas complicates the development of management systems for the material and technical resources of rural health care. Given that modern information technologies are widely used in health care, a topical solution of this problem is the automatic collection, processing, storage and analysis of data on material and technical equipment of rural health care. The aim of the research is to develop an automated information system that provides the collection of indicators of the material and technical equipment of rural health care for monitoring purposes. To achieve this goal, methods to collect, process and analyze information on the equipment of feldsher-midwife stations and outpatient clinics were used. Automated system "Monitoring of material and RESUMEN: La falta de información confiable sobre el estado de los activos fijos de las instituciones médicas ubicadas en áreas rurales complica el desarrollo de sistemas de gestión de los recursos materiales y técnicos de la atención de salud rural. Dado que las modernas tecnologías de la información son ampliamente utilizadas en el cuidado de la salud, una solución tópica de este problema es la recolección, procesamiento, almacenamiento y análisis automáticos de datos sobre el material y el equipo técnico de la atención médica rural. El objetivo de la investigación es desarrollar un sistema de información automatizado que proporcione la recopilación de indicadores del material y el equipo técnico de la atención de salud rural para fines de monitoreo. Para lograr este objetivo, se utilizaron métodos para recopilar, procesar y analizar información technical management of rural health care" was developed as a result of the study.

Modernization of accounting of material and technical management of rural health care through information technology

The results obtained from combined numerical and experimental investigations of the water decarbonization process carried out in atmospheric-pressure deaerators without subjecting water to steam bubbling in the deaerator tank are presented. More exact values of the hydrocarbonate thermal decomposition rate have been obtained, and the hypothesis about a change of the process governing mechanism in shifting to low total alkalinity values of deaerated water has been proven in the course of these investigations. A procedure for predicting the indicators characterizing the water decarbonization efficiency in using deaerators is proposed based on the obtained study results. The developed procedure features the maximally possible accuracy that can be achieved at the metrological characteristics of the standard alkalinity measurement methods.

Predicting the indicators characterizing the water decarbonization efficiency when using atmospheric-pressure thermal deaerators without subjecting water to steam bubbling in the deaerator tank

The article deals with the problem of the correct calculation of energy efficiency indicators for the operation of CHP plants in the combined production of heat and electric energy. The authors review traditional methods, which are more often used in Russia and in the countries with developed markets of electricity and heat. They develop a new method for calculating energy efficiency indicators for the operation of cogeneration steam turbines using mathematical models based on the actual power and flow characteristics of turbine stages and compartments. The problem solutions are based on generalized experimental data and theoretical positions of technical thermodynamics, the theory of heat and mass transfer, gas dynamics, the theory of turbomachines and mathematical modeling of thermal power plants, numerical and physical experiments and proven techniques of technical and economic research in the energy sector under market conditions. The authors compare the proposed method for calculating variable operating conditions of steam turbines using formulated principles and calculation results based on regulatory characteristics, and the most effective methods are identified. The proposed approach can be implemented and used to optimize the operation of CHP plants in the Russian wholesale electricity and capacity market.

Comparative and Optimizing Calculations of Energy Efficiency Indicators for Operation of CHP Plants Using the Normative Characteristics and Mathematical Models

Analysis of dynamic characteristics of marine deaerator

The problem of striking material and energy balances from the data received by thermal power plant computerized automation systems from the technical accounting systems with the accuracy determined by the metrological characteristics of serviceable calibrated instruments is formulated using the mathematical apparatus of ridge regression method. A graph theory based matrix model of material and energy flows in systems having an intricate structure is proposed, using which it is possible to formalize the solution of a particular practical problem at the stage of constructing the system model. The problem of striking material and energy balances is formulated taking into account different degrees of trustworthiness with which the initial flow rates of coolants and their thermophysical parameters were determined, as well as process constraints expressed in terms of balance correlations on mass and energy for individual system nodes or for any combination thereof. Analytic and numerical solutions of the problem are proposed in different versions of its statement differing from each other in the adopted assumptions and considered constraints. It is shown how the procedure for striking material and energy balances from the results of measuring the flows of feed water and steam in the thermal process circuit of a combined heat and power plant affects the calculation accuracy of specific fuel rates for supplying heat and electricity. It has been revealed that the nominal values of indicators and the fuel saving or overexpenditure values associated with these indicators are the most dependent parameters. In calculating these quantities using different balance striking procedures, an error may arise the value of which is commensurable with the power plant thermal efficiency margin stipulated by the regulatory-technical documents on using fuel. The study results were used for substantiating the choice of stating the problem of striking material and fuel balances, as well as the method for solving it. With the problem statement and the solution method implemented in the real thermal power plant computerized automation systems, less biased calculation of actual thermal efficiency indicators of equipment is obtained.

Algorithms for striking material and energy balances in calculating the technical-and-economic indicators of thermal power plant equipment based on the ill-posed problem regularization method

This paper presents the results of calculation-based and experimental investigations into static and kinematic conditions of removing free and chemically bonded carbon dioxide from water in jet-type open deaerators.

Special features of the water decarbonation in thermal jet-type open deaerators

The problem of optimal generation and transmission of energy in a system of heat and electric networks is formulated. An analytical solution to the problem is obtained using the Lagrange indeterminate multipliers method. An example of solving a practical problem is given.

Optimal generation and transmission of energy in heat and electric networks

A cellular matrix approach is proposed for calculating transients that occur during thermal deaeration with possible variations in the level of system decomposition due to the available support by empirical data. Matters relating to optimal control of the process are discussed.

E. V. Barochkin

Papers

Predicting the indicators characterizing the water decarbonization efficiency when using atmospheric-pressure thermal deaerators without subjecting water to steam bubbling in the deaerator tank

Algorithms for striking material and energy balances in calculating the technical-and-economic indicators of thermal power plant equipment based on the ill-posed problem regularization method

Special features of the water decarbonation in thermal jet-type open deaerators

Optimal generation and transmission of energy in heat and electric networks

Simulation and optimization of transients in thermal deaerators