Search

Steel underground gas pipelines occupy a significant share of the total length of gas distribution pipelines, and therefore their maintenance in proper condition is a constant and very urgent task. Due to its global nature, the main influencing factor affecting the technical condition of any steel underground pipelines, including gas pipelines, is corrosion, primarily soil corrosion. To protect against it on pipeline networks, along with insulating coatings, electrochemical protection (ECP) is applied, that is, following the definition of STO [Standard of Organization] 17330282.27.060.001–2008, protection of metal against corrosion in an electrolytic environment, carried out by establishing a protective potential on it or eliminating the anodic potential shift from the stationary potential. In the gas distribution industry of the country, methods and means of electrochemical protection have been applied since the beginning of gasification and the construction of the first gas pipelines. All gas supplying organizations of the State Production Association for Fuel and Gasification “Beltopgaz” (six regional and Minsk city), which operate gas distribution facilities, have specialized corrosion protection services. These services provide maintenance of available ECP equipment, conduct electrical measurements on gas pipelines and corrosion studies of soils, and have certified laboratories. This paper is devoted to the analysis of domestic experience in organizing electrochemical protection of steel underground gas distribution pipelines, searching for promising directions for its improvement and increasing efficiency through the implementation of a unified industry technical policy, automation and telemechanization of ECP equipment in the general context of digital transformation, optimization of the timing and volume of maintenance.

One of the main types of maintenance of steel underground gas distribution pipelines is periodic instrument inspection. This inspection is a kind of operational control, which includes detection of defects of insulation coating and gas leaks by instrumental methods, without opening the pipeline. This simultaneously controls two different levels of failure of the gas pipeline’s serviceability, one of which fully preserves its operability, but creates the possibility of a chain of events threatening to cause a failure in the future (insulation defect), while the other level of failure is, in fact, the case when the failure has already occurred (loss of tightness of the gas pipeline), but before the examination was not detected. All underground gas distribution pipelines are subjected to an instrument inspection with a certain regulatory frequency. The identified damages are subject to mandatory elimination, the serviceability and operability of the gas pipeline are being restored. Thus, periodic instrument inspection is a key technical measure that ensures the management of the technical condition of steel underground gas distribution pipelines. It should be mentioned that the work carried out during the inspection and further repair of gas pipelines is the most extensive and labor-consuming of all those performed on the linear part of the gas distribution system. Accordingly, adequate planning in this area is very important from the point of view of both the reliability and safety of the gas distribution network and the economic and economic one. At the same time, it is quite difficult to ensure the required adequacy of operational control planning and maintenance of engineering facilities in practice, since the maintenance process itself combines regulated and unregulated components and has significant inertia of management. The present article is devoted to the issues of reasonable forecasting of the scope of work on the instrument inspection of steel underground gas pipelines, taking into account a specially identified complex organizational and logistical factor reflecting the influence of existing production practices and management approaches in the field of gas distribution. The forecast is based on the currently relevant time series analysis methods.

At industrial CHP plants which are characterized, in particular, by steam supply to industrial consumers, in cases with significant condensate losses, it is proposed to develop a system of feed water regenerative heating by utilizing low-temperature waste heat flows those are available directly at the CHP plant. The regenerative use of low-temperature heat flows within the CHP that is proposed is possible only on the basis of heat pumps use. In this context, the use of electrically-driven heat pumps (EHP) and absorption heat pumps (AHP) is considered. It is shown that, despite the higher heating coefficient of the EHP, the thermodynamic (exergetic) efficiency and economic efficiency of the AHP are higher. Furthermore, the latter also has operational advantages. It is possible to use heat flows with various heat carriers as AHP drive, those are required for the transfer of thermal energy from a cold source to a hot receiver. In this paper, using the example of the “PT-60” steam turbogenerator unit, which is the most common type for CHP plants of the Belarusian power system, the indicators of the primary fuel use efficiency growth at the CHP plant for the AHP with a steam drive are determined. Three scenarios of the use of AHP as part of the thermal scheme of the CHP are considered, viz. with an increase in generation, with the maintenance of generation or with a decrease in the generation of electric energy. The latter is relevant in the current situation with the Unified Energy System of Belarus. In this case, while maintaining the minimum steam flow into the condenser of 12 t/h, the following increase in the plant efficiency has been obtained: electrical efficiency increased by 0.90 %, energy efficiency – by 0.55 %, and exergetic efficiency – by 0.23 %.

The energy system is a structure that is among the most complex artificial objects, the successful functioning and development of which is absolutely necessary to ensure the livelihoods of a modern state. In this regard, its continuous monitoring with obtaining reliable and objective performance indicators is undoubtedly in demand. Traditional key energy indicators (specific consumption of conventional fuel for electricity generation and heat release) do not give a complete picture of the operation of the power system for such complex structures and in some cases are calculated incorrectly. The present paper proposes to add a well-known, but practically unused exergetic efficiency coefficient to the range of traditional characteristics. Its application expands the monitoring capabilities and increases the objectivity of the evaluation. For the first time, the analysis of various periods (annual, heating and inter-heating) was carried out on the example of thermal power plants (CHP) of the Unified Energy System of Belarus. The relative power generation of the CHP before the commissioning of the Belarusian NPP was estimated at ≈45 %, and after commissioning it decreased to ≈39 %. More than half of the annual consumption of thermal energy in Belarus is accounted for by heat-generating sources, while thermal power plants provide up to 88 % of heat output. The installed electric capacity utilization factor, the extraction factor and the average annual specific generation of electricity on thermal consumption for each CHP separately have been determined. The results are presented graphically, which makes the content more informative and facilitates the perception. Solutions have been proposed to improve the efficiency of the CHP.

The energy system is one of the foundations of a modern state, so, the need for its successful development and functioning is beyond doubt. In this regard, an objective assessment based on a set of indicators (viz. economic, energy and thermodynamic) is relevant. However, the traditional assessment of the operation of the energy system is carried out on the basis of such characteristics as the specific consumption of conventional fuel for electricity generation and heat release, which does not provide a comprehensive picture and is not always applied correctly. In this article, for the first time on the basis of the exergetic method, the calculation of the exergetic efficiency is considered. The use of this indicator makes it possible to obtain an objective assessment of the thermodynamic efficiency of such a complex formation as the energy system of a modern country in the easiest way. As an example, the unified energy system of Belarus in general and condensing power plants in particular have been analyzed for a fairly long period (2000–2021) and in various characteristic time periods. The method of calculating the exergetic efficiency is described. The results obtained are presented graphically. Attention is paid to the issue of the acceptability of the error when generalizing data on the initial flows of primary energy resources and product flows of centralized generating sources of the energy system. The contribution of condensing power plants to the total volume of electricity generation is analyzed, the most advanced of them are determined from a thermodynamic point of view. The calculation of their energy and exergetic indicators was carried out; the changes associated with the commissioning of the Belarusian NPP were considered. The conclusion is made that further reconstruction of energy sources of the power system in order to reduce the relative weight of natural gas in the incoming part of the energy balance to 50 % is expedient. This can be achieved by increasing the thermodynamic efficiency.

In the present-day conditions, the issue of energy saving is becoming increasingly acute and permanently relevant. This situation is caused by rapid growth in prices for primary energy resources and by the need to reduce the share of natural gas in the incoming part of the energy balance of Belarus. According to available statistics, with the commissioning of the Belarusian NPP, the share of natural gas in the incoming part of the energy balance decreases from 97 to 59 %. In the economic complex, the share of this primary energy resource is projected at 70 %. The problem of energy saving is solved most rationally and with the least investment only by increasing the efficiency of natural gas use, especially due to the commissioning of the Belarusian NPP, the issue of preserving the possibility of using centralized heating facilities is acute. It is necessary to increase the thermodynamic efficiency of the cycles of steam turbine plants, both heating and condensing, which form the basis of the generation of the Belarusian power system, in order to restore the energy characteristics of the power system, which have somewhat decreased with the commissioning of the NPP. In the limit, the share of natural gas in the incoming part of the energy balance should be reduced to values not exceeding 50 %, in accordance with the requirements of energy security. The article considers examples of utilization of low-temperature secondary energy flows occurring at thermal power plants: the heat of the cooling processes of the generator, lubrication systems, as well as the heat of condensation of turbine exhaust steam and deeper cooling of flue gases. On the basis of this review, it is expected to identify promising areas of relevant research in relation to the energy system of Belarus.

. The results of numerical studies carried out on the basis on a mathematical model developed by the authors of this paper devoted to the investigation of the influence of various factors on the characteristics of the process of heat treatment of composite products in industrial heat technology installations in the presence of internal heat emissions distributed over the volume of individual layers of the product are presented. The formulation of boundary conditions for this model is proposed, considering the multilayer structure of products and the peculiar properties of the organization of their heat treatment process in a heat technology installation. A detailed description of the mathematical model was presented in the previous works. In this study, the functions of temperature distribution and the coefficient (degree) of hydration in the spatial regions that make up the product have been studied as characteristics of the heat treatment process. Model composite products of the same shape and structure but of different volume, consisting of two layers of material in which an exothermic hydration reaction takes place separated by a layer of expanded polystyrene were considered. The temperature-time regime of heat treatment was assumed to be close to that used in industrial conditions in the production of three-layer external wall panels. The boundary and initial conditions corresponded to the conditions of heat treatment on flat stands with water heating and sheltering products from above. It has been determined that the presence of a thermal insulation layer in the core of the product separating the layers that have an internal heat source, changes the distribution of temperature values and the hydration coefficient in the upper and lower layers significantly. An increase in the characteristic volume of the product leads to an increase in the influence of internal volumetric heat release on the processes of heating and hydration, while heat release caused by the course of the hydration reaction begins to have a decisive influence on them.

An assessment is given to the problems of urban wastewater sludge utilization in our country and abroad, with determination of formation and usage level. Global trends in the reduction of carbon dioxide emissions exacerbate the urgency of solving the designated tasks. At the same time, recently, in connection with the EU’s plans to introduce a cross-border carbon levy, it has become necessary to reduce the carbon footprint from burning traditional fuels, which is an urgent problem of modern society. One of the directions that provide a solution to this problem is the replacement of part of the hydrocarbon fuel by the consumption of multicomponent solid fuel based on the use of combustible waste that is part of the multicomponent fuel. This solid fuel can be used to meet the needs of small consumers, for example, in the autumn-summer period to generate a drying agent for the preparation of grain on the threshing-floor, in small boiler houses, in sand drying plants of locomotive depots, heat installations of hangars and workshops, as well as in other heat-generating installations operating on solid fuels. At the same time, solving the problem of reducing the carbon footprint for Belarus is closely related to another urgent task – reducing the energy component of industrial products and the environmental consequences of storing accumulated and generated waste. The paper presents the results of joint scientific research in the field of application of modern technologies and equipment using electrohydraulic treatment to reduce and minimize the level of anthropogenic and polluting substances in wastewater sludge. The described technological equipment, technology and post-treatment modes reduce the content of harmful substances in the wastewater sludge composition even with short-term treatment. An assessment of the effectiveness of the developed technology for the use of sewage sludge is given, using the method of wet multicomponent briquetting to obtain a multicomponent fuel. The presented process flow diagram of multicomponent briquetting using sewage sludge and plant-wood waste directly shows the undeniable advantages of using watered wastewater sludge as a raw material for the production of solid fuel. At the same time, the optimally selected ratio of components and moisture content of the briquetted composition solves a number of technologically difficult problems that cannot be realized using traditional briquetting technologies. The presented data of the conducted research and the developed technology make it possible to expand the area of using wastewater sludge as a secondary renewable material resource.

This article is the second part of the research devoted to the exergetic analysis of heat treatment processes of concrete products in heat technology installations. In the first part, the issues of calculating the exergy of a concrete mixture and hardening concrete have been considered, taking into account all the components of the exergy, viz. reaction, concentration and thermomechanical ones. In the present part of the study, exergetic criteria are proposed that make it possible to evaluate the energy efficiency of the operating modes of heat-technological equipment for the heat treatment of concrete products. These include the degree of thermodynamic perfection of a heat-power system, which is used to evaluate the completeness of the use of the exergetic input; thermodynamic efficiency of the system of heat treatment of concrete products in heat technology installations, representing the degree of thermodynamic perfection of the heat power system that is calculated without taking into account all the components of the sum of transit exergies; thermodynamic efficiency of the heat treatment system, taking into account the exergetic efficiency of the system of heat energy production and transportation; the degree of technological perfection that indicates at the portion of the exergy supplied to the heat technology installation for the heat treatment of concrete products is intended to obtain a technological result. To calculate the listed indicators and characteristics, a mathematical apparatus is proposed that takes into account the mass of the concrete product, the specific mass exergy of cement and hardening concrete, the specified degree of hydration of cement in concrete at the end of heat treatment, the exergetic flows supplied to the product in a heat technology installation during its heat treatment, and numerical indicators characterizing the incompleteness of the cement hydration process. The results obtained in this paper are discussed from the viewpoint of their applicability in the selection of heat treatment modes. They can be used in the selection of energy-saving modes of heat-technological equipment for industrial heat treatment of concrete products.

Having proven its effectiveness in finding the best options for energy supply and energy consumption the exergetic method of thermodynamic analysis of complex heat and power systems has been widely recognized in recent years. However, its application is hindered by the lack of appropriate scientific and methodological heat technology support, especially if their application involves not only transformation of energy, but also transformation of substances. Heat treatment of concrete and reinforced concrete products belongs to such technologies. This article presents new scientific results related to the development of exergetic balances of the processes of preparation of concrete mixture in a mixer and heat treatment of a concrete product in a heat-technological installation. For each of these cases, the analysis of exergetic flows was carried out, the structure of the exergy of the concrete mixture and the hardening concrete was determined. Based on the analysis of the literature data on the chemical composition of cement clinkers, cements, and hydration products, new dependences have been proposed for calculating the exergy of the concrete mixture flow and the exergy of concrete under its heat treatment, including all their components, viz. thermomechanical, reaction, and concentration constituents. Absolute energy indicators have been developed. The calculation of the mentioned values was performed on a specific example with the use of the developed scientific and methodological support. In the second part of this paper, the results of the study related to the determination of relative exergetic indicators that allow evaluating the energy efficiency of the processes of heat treatment of concrete products in heat technology installations will be published. The results obtained in this paper can be used for the selection of energy-saving modes of heat-technological equipment intended for industrial heat treatment of concrete products.

Production of concrete and reinforced concrete products in the conditions of the Republic of Belarus and in the countries with similar climatic conditions requires heat treatment in heat-technological installations in order to achieve the desired strength of the products at the appointed time, which consumes a great amount of thermal energy. In this case, the purpose of equipment operating modes is associated with a number of difficulties when it comes to new products of complex spatial configuration and structure. The optimality criteria of such modes are, as a rule, the duration and temperature limits of processing, providing the required strength with minimal energy consumption. In the conditions of serial production in the case of structurally simple objects, the assignment of heat treatment modes is carried out empirically. As the analysis shows, the modes obtained in this way do not meet the above criteria, especially from the standpoint of energy saving. The paper, using a mathematical model previously developed by the authors, proposes dependencies for calculating the optimal modes of heat treatment of concrete products that are distinguished by a complex spatial shape and multi-component structure. The method is based on three-dimensional transfer equations, taking into account internal sources of heat release due to the ongoing hydration reaction of the active components of the cement clinker, and the boundary conditions corresponding to the structure of the processed product, as well as the type of heat technology device for accelerated hydration. Equations are proposed for calculating the amount of heat energy supplied to the processed product providing a given strength at a specified time. On the example of a manufactured industrial concrete product and for the conditions of an actually used device for accelerated hydration, a comparison has been made between two limiting modes of heat treatment: with isothermal exposure and in its absence. As a result of the performed calculations, the dependences of energy consumption, temperature fields and the degree of hydration in the product for both modes have been obtained and an energy-saving mode of heat treatment corresponding to the case under consideration has been developed. It is shown that the used numerical method allows to solve problems of this type and to achieve thermal energy savings.

In the article the technique of an assessment of modes of operation of the heat engineering equipment used for heat treatment of concrete products in the conditions of programcontrolled heat supply according to the pattern of “heating – isothermal influence – cooling” has been developed. The method is based on the numerical solution of a non-stationary heat equation supplemented by equations describing the hydration process of a concrete product; also, it includes a system of initial and boundary conditions for its spatial structure. The method makes it possible to create tabulated functions of temperature and the degree of hydration of the time of heat treatment in any point of a 3D-product. The mathematical tools for calculating the functional dependencies of concrete hydration equipment with software-heated environment are presented. Numerical calculations of the concrete hydration process in the formwork are performed with respect to the symmetrical object. Based on the calculation of the temperature gradient across the minimal cross section of the product, a numerical analysis of the functions modeling heat supply mode depending on the processing time of a concrete product has been fulfilled. It is demonstrated that the maximum speed of the hydration process in a concrete product hardening is achieved at the maximum of time lag of isothermal cure. Additionally, with an increase in the duration of the product heating, the value of the maximum hydration rate decreases. It is concluded that the method of assessing the mode of heat treatment of concrete products being developed makes it possible to determine parameters for the calculation of the minimal useful heat required for the heat treatment of concrete products with spatially distributed parameters. The proposed method is applicable to calculate the temperature fields and the extent of hydration in the products of any geometric shape and volume in a software-controlled heating environment of industrial facilities for the accelerated hydration of concrete, and also affords the possibility of preliminary calibration prior to the assignment of relevant heat supply modes to the products being processed.

In industrial heat-technological installations for accelerated hydration of concrete, which are the main element of the thermal power system of enterprises of concrete products, the modes of heat treatment and the organization of heat supply to the product processed in them are due to the required temperature distribution in the volume of the concrete body, providing a given product quality. In order to optimize the processes occurring in such thermal device, a nonstationary mathematical model of the hardening process of the concrete product subjected to heat treatment has been developed, which allows calculating the spatial distribution of its volume temperature and degree of hydration of the active part of the cement clinker. The proposed model is based on the use of a non-stationary three-dimensional heat equation that takes into account the internal heat release due to the exothermic reaction in a concrete body and determines the degree of its hydration and hardening. For a given mode of heat treatment with the use of the finite volume method, numerical simulation of the hardening process of a symmetric concrete object of cubic shape is performed. In the selected points of the object under study, depending on the time of heat treatment, the rates of temperature change and the degree of hydration were calculated and their analysis was carried out. When analyzing the graphs of the temperature change rate, the characteristic inflections consistent with the given thermal mode of the heater were revealed. By a given mode of heat treatment of the form of “temperature rise – isothermal exposure – temperature decrease” in the selected points of the object there is an increase in temperature compared with the specified maximum temperatures of isothermal exposure, which is associated with the exothermic effect of the hydration reaction. A temperature shift relative to the specified thermal mode of the heater due to the non-equilibrium of the concrete hardening process is observed. The proposed mathematical model allows determining the time of reaching a preset temperature for any point of the internal space of the product subjected to heat treatment that can be used in the when designing of new and modernizing of existing thermal technological installations of accelerated hydration of concrete, as well as systems for automated control of the concrete hardening process in these devices. The results obtained during the study are in satisfactory agreement with the experimental data of other authors.

Thermo-technical installations consuming significant amounts of thermal energy are used in order to intensify precast and reinforced concrete production processes under industrial conditions. Despite significant progress in the study of concrete hardening in accelerated hydration devices, a prominent lack of reliable and cost-effective research and optimization methods of their operation is observed. The methods used in real production processes are mainly based on empirical dependences obtained for specific technological conditions. These methods can not always be applied for other modes and technologies. The present paper develops calculation methods based on fundamental laws that make it possible to obtain functions for evolution of concrete product hydration process. Methods of mathematical modeling permit to develop new ways directed on improvement of modes for heat treatment of concrete products and accelerated hydration technologies. The paper describes a mathematical model for calculating a hardening process of a concrete product that includes a transient three-dimensional heat conductivity equation, a function of internal heat release due to behavior of exothermic reactions of cement hydration and also a system of initial and boundary conditions. A numerical simulation for temperature and hydration coefficient of a concrete product having shape of a 0.1´0.1´0.1 m cube has been performed in the paper. Verification of the non-stationary mathematical model for calculating temperature fields and hydration degree while using experimental data on concrete product strength obtained under industrial conditions. Investigations on hydration degree function of time have shown that experimentally obtained values of compressive strength correlate with hydration coefficient and hydration rate functions of heat treatment time which are calculated on the basis of the proposed non-stationary mathematical model of concrete product hardening. Satisfactory agreement of experimental and calculated data confirms adequacy of the proposed non-stationary mathematical model for calculating temperature fields and hydration degree with accelerated heat treatment of concrete products.

Further improvement of natural gas usage in power industry is associated with transition to the combined-cycle gas technology, primarily at combined heat and power plants (CHP). Renovation of technology of conversion of fuel energy into heat and electricity flows is effective while it is performed simultaneously with the elaboration of thermal circuits of CHP by insertion heat accumulators and absorption lithium bromide heat pumps (ALBHP) in the structure of CHP; the mentioned insertion amends thermodynamic as well as economic and environmental indicators of CHP renovation and also develops CHP maneuverability. The ability of CHP to provide heat in required quantity, their capacity to change electricity generation output without excessive fuel consumption is extremely relevant for the energy system that incorporates thermal power plants as dominating component. At the same time the displacement of traditional electrical power regulators take place. Implementation of projects of this kind requires the elaboration of CHP flow diagram calculation methods and determining relevant indicators. The results of the numerical study of the energy characteristics of CHP with the aid of the topological models of the existing heat flow diagrams of CHP that incorporate ALBHP for recovery of low-temperature waste of heat flows of systems of cooling water circulating are presented in the article. An example of calculation, the results of the CHP thermodynamic efficiency evaluation, the change of the energy characteristics for different modes of operation of CHP caused by implementation of ALBHP are shown. The conditions for the effective application of lithium bromide absorption heat pumps are specified, as well as the rate of increase of thermodynamic efficiency; the changes of maneuverability of CHP with high initial parameters are identified, the natural gas savings in The Republic of Belarus are determined.

The paper considers organization of the industrial enterprise heat and power supply system (HPSS), to be rational from the structure and flow parameter standpoint. Developing HPSS is one of the main lines of implementing energy-saving potential in volumes complying with dictates of the time on reducing the production cost energy component, which is especially vital for the light industry enterprises of Belarus. To reduce the complexity of the task the authors employ the hierarchical structure of HPSS. With regard to textile and knitwear enterprises, they show the irregularity of energy supply on the one hand, and of energy use on the other. The finishing departments of the specified enterprises ensure their thermo-technological status. It is proverbial that accomplished in terms of energy thermo-technological enterprises should not consume the electric energy produced in condensation electric power plants. Instead, for their production needs, they should use thermal energy and electricity generated in the CHP. At the same time, steam turbine CHPs of low power, and consequently of low initial parameters, cannot provide the required electrical and heat energy flow generation balance. The indicated circumstance among others accounts for prevalence of condensation electric power plants in the scheme of electrogenerating capacities that provide work for the light industry enterprises. And this leads to irregularity of their energy supply. Transition to gas CHPs with required scheme of the energy flow generation is associated primarily with creation of inherent generating sources, which in its turn poses a number of challenges on modification of the thermal treatment schemes of technological flows. The problem is solved in package with developing energy consumption of the finishing department as well as the entire enterprise. The study shows the capability of utilizing low pressure hot water alongside with steam, which paves the way to the recuperative use of the secondary low-temperature heat flows – utilizing their energy by engaging lithium-bromide absorption heat pumps. The congruous development of energy utilization from the position of systems approach in the context of Belarus is the task of a higher priority than transition to cogeneration energy supply.

Road construction is one of the most material-intensive industrial production. In this context, the urgent task for this branch is the maximum reduction in consumption of materials through usage of effective local materials, decrease energy intensity of processes by using new materials. The developed network of local roads require constant care and maintenance, thus it is advisable to consider the use of protective coatings for such roads on the basis of contactcondensation hardening, which can be obtained on the basis of local raw materials. One of the representatives of such material is disperse hydrated calcium silicate, which found wide practical application as the main components in the production of building materials, glass, glass ceramics and ceramic products. For example, relatively cheap highly dispersed crystalline material is intermediate product of hydrochemical synthesis of wollastonite xonotlite Ca6(Si6O17)(OH)2. A variety of calcium and silicon-containing raw materials, suitable to obtain various types hydrated calcium silicate, as well as increasing requirements for physical and chemical properties, caused by actuality of problems of search and study the best ways of synthesis hydrated calcium silicate from man-made and natural materials. The theoretical basis of the proposed technology for material production for road pavement lower categories is the ability of silicate dispersed materials transferred in an unstable state, forming a rock-like waterproof body at the time of application of mechanical load. Disperse hydrated calcium silicate are the most typical representatives of contactcondensation hardening binders. It should be noted that the technology of obtaining these binders is not related to high-temperature processes and the synthesis of HCS realized when wet treatment of available cheap raw materials on the standard equipment, what determines their practical significance.

The paper offers the results of pinch analysis, thermodynamic analysis based on exergy method that determine the energy-supply efficacy enhancement variants for the processing equipment in the light industry finishing production as exemplified by the apparatuses of batch operation for textile dyeing. Scientifically substantiated improvement feasibility estimation for the Belarusian light industry enterprises thermo-technological production energy supply is of current concern and in demand in the existing economic situation. Exergy method allows obtaining the indicated estimation by the simplest and most logical way as against the other methods of thermodynamic analysis e.g. entropy method or employing the cycle theory. Pinch analysis employment not only allows verifying the estimation results but also points out the problem spots demanding cardinal changes and modernization. This complex approach renders possible outlining simple ways of energy saving in the existing technical systems of substance transformation, which is important under the conditions of operating production for successful handling the problem of lowering production costs. The example of the most widespread thermo-technological production of the light industry illustrates the above stated. For most enterprises of the republic, it remains problematic in many ways. The suggested ways of solving the problem are not exhaustive and offer evolutionary changes that secure economic indicators fitting the dictates of time and the enterprises capabilities. Another critical factor of the presented analysis and ways for thermo-technological energy supply improvement is that the proposed changes can realize on basis of the equipment that established a good reputation during continuous service in different productions and manufactured in the republic in working partnership with foreign design engineers.

The paper ascertains and presents alteration in the energy consumption as a consequence of utilizing the low-temperature waste streams commonly used in the lines of continuous dyeing at the finishing shops of textile enterprises of Belarus. The utilization realizes through the engagement of lithium-bromide absorption heat pumps with various energy characteristics such as the heating coefficient (relative conversion ratio COPhp = 1,15; 1,7; 2,2) and the heating capacity. The latter associates with the converted heat-flow energy utilization variant with the heat-transfer medium heating system scheme (one-, twoand multistage heating). The article considers transition to previously not applied service-water preheating due to the technological acceptance of feeding higher temperature water into the dyeing machine and widening specification of the heattransfer media. The authors adduce variants of internal and external energy use and their evaluation based on the relative energy and exergy characteristics. With results of the thermodynamic analysis of the modernized production effectiveness the researchers prove that alongside with traditional and apparent interior utilization of the energy associated with the stream heat recuperation, it is advisable to widen the range of applied heat-transfer media. The transition to the service water twoand multi-stage preheating is feasible. The study shows that the existing energy supply efficiency extremely low index-numbers improve by one or two degrees. Since they are conditioned, inter alia, by the machinery design, traditional approach to energy supply and heat-medium usage as well as the enterprise whole heating system answering requirements of the bygone era of cheap energy resources. The authors examine the continuous dyeing line modernization options intending considerable investments. Preliminary economic assessment of such inevitable modernization options for the enterprise entire heat-and-power system shows reality of meeting all going with the times requirements such as economic, environmental, energy for similar projects.

One of the main directions in construction material science is the development of next generation concrete that is ultra-dense, high-strength, ultra-porous, high heat efficient, extra corrosion-resistant. Selection of such direction is caused by extreme operational impacts on the concrete, namely: continuously increasing load on the concrete and various dynamics of such loads; the necessity in operation of concrete products in a wide temperature range and their exposure to various chemical and physical effects.The next generation concrete represents high-tech concrete mixtures with additives that takes on and retain the required properties when hardening and being used under any operational conditions. A differential characteristic of the next generation concrete is its complexity that presumes usage of various mineral dispersed components, two- and three fractional fine and coarse aggregates, complex chemical additives, combinations of polymer and iron reinforcement.Design strength and performance properties level of the next generation concrete is achieved by high-quality selection of the composition, proper selection of manufacturing techniques, concrete curing, bringing the quality of concrete items to the required level of technical condition during the operational phase. However, directed formation of its structure is necessary in order to obtain high-tech concrete.Along with the traditional methods for regulation of the next generation concrete structure, modification of concrete while using silica nanoparticles is also considered as a perspective one because the concrete patterning occurs due to introduction of a binder in a mineral matrix. Due to this it is possible to obtain nano-modified materials with completely new properties.The main problem with the creation of nano-modified concrete is a uniform distribution of nano-materials in the volume of the cement matrix which is particularly important in the cases of adding a modifier in micro-quantities. An additional environment is required in order to solve this problem and the environment will form a continuous phase in the composite. This function can be performed by liquid or dispersed phase.

The proposed paper is a continuation of the work, published in the previous issue. It is destined for specialists who are engaged in solution of problems pertaining to efficiency of light industry in Belarus which is considered as one of the branches being significantly involved in formation of national economy, its export potential and social climate. It is extremely relevant to reduce production costs in order to preserve and add strength to the branch positions in the markets. Production of natural, synthetic and knitted materials and their subsequent treatment are unreasonably power-consuming processes. Fundamental solution of the problem for reduction of production costs is to decrease its energy component and this can be achieved due to transition to modern heat and power systems in technological complexes of enterprises.The first part of the paper has considered a range of issues that served as a basis for obtaining statistical models in order to forecast the required production volume of main knitted and textile materials. Forecasting has been prepared for a period of more than 20 years because it has been predetermined by development horizon of comprehensive modernization of energy supply systems at enterprises of light industry. The production volumes essentially differ from those that have been stipulated in the programs of light industry.The present paper shows selection of statistical game-type for determination of build-up rate of the production volume for every textile enterprise. The so-called “Game with Nature” has been selected as a game which is widely used for solution of analogous demand problems. The statistical forecasting models of production obtained in the first part are applied in the second part of the paper which considers strategies for development of individual enterprises. JSC :Baranovichi Industrial Cotton Association” has been taken an example in the paper. Production volumes of any enterprise are determined on the basis of the development strategies with due account of risk minimization and obtaining maximum average expected profit. The average expected production of the enterprise is determined from these strategies in the light of minimizing risks and maximizing profits. Fundamental capacity of power consumption for designing their own cogeneration plants can be determined while using the concept of intensive energy saving. The concept prescribes implementation of a systematic approach that takes into account the necessity of maximum utilization of secondary low-temperature production flows, specificity in consumption and generation schedules of energy flows, conditions of an industrial unit that includes the enterprise, requirements of the power system of Belarus under conditions of NPP operation.основе концепции интенсивного энергосбережения можно установить базовую мощность энергопотребления для проектирования собственных когенерационных установок. Концепция предписывает реализацию системного подхода, учитывающего необходимость максимальной утилизации побочных низкотемпературных потоков производства, специфику графиков потребления и генерации энергопотоков, условия промышленного узла, в который входит предприятие, и требования энергосистемы Беларуси в условиях работы АЭС.

The paper deals with the structural specifics of the Belarus Consolidated Energy System capacities in view of their ongoing transfer to the combined-cycle technology, building the nuclear power plant and necessity for the generating capacity regulation in compliance with the load diagram. With the country’s economic complex energy utilization pattern being preserved, the generating capacities are subject to restructuring and the CHP characteristics undergo enhancement inter alia a well-known increase of the specific electricity production based on the heat consumption. Because of this the steam-turbine condensation units which are the traditional capacity regulators for the energy systems with heat power plants dominance are being pushed out of operation. In consequence of this complex of changes the issue of load diagram provision gains momentum which in evidence is relevant to the Consolidated Energy System of Belarus. One of the ways to alleviate acuteness of the problem could be the specific electric energy production cut on the CHP heat consumption with preserving the heat loads and without their handover to the heat generating capacities of direct combustion i.e. without fuel over-burning. The solution lies in integrating the absorption bromous-lithium heat pump units into the CHP thermal scheme. Through their agency low-temperature heat streams of the generator cooling, the lubrication and condensation heat-extraction of steam minimal passing to the condenser systems are utilized. As a case study the authors choose one of the CHPs in the conditions of which the corresponding employment of the said pumps leads to diminution of the fuel-equivalent specific flow-rate by 20−25 g for 1 kW⋅h production and conjoined electric energy generation capacity lowering. The latter will be handed over to other generating capacities, and the choice of them affects economic expediency of the absorption bromous-lithium heat pump-units installation decision.

The paper presents an interest for those specialists who are involved in solution of efficiency problems in light industry of Belarus as one of the significant industries that forms an economic situation in the Republic, its export potential and social climate. It is extremely relevant for the Belarusian enterprises to reduce production costs in order to preserve and strengthen positions in the light industry market. Operating capacities for production of natural, synthetic textile and knit-wear materials and their subsequent treatment are in many respects unjustifiably energy intensive. Nowadays the only acceptable solution of the problem for reduction of production costs is to decrease its energy component. Such approach requires transition to creation of modern heat and power supply systems at heat technology enterprises.The most important sub-system of the enterprises is own combined production of energy flows of secondary electrical and heat energy, freeze. There is a complex of problems that arise during designing process of tri-generation unit. One of the most important problems presupposes determination of a base load demand and capacity of every energy flow generated by an energy source. The solution is directly related to production output, which in its turn is determined by the requirements of sales markets. Due to various reasons the markets have their own specificity for the enterprises under consideration. It is proposed to use statistical methods for searching requirements. In this connection it is necessary to take into account industry development rate (pre-determined by State Programs, Plans, Governmental solutions, including directive instructions), production volumes of competitive goods and actual goods situation on the sales market.The paper presents the first part of the executed complex investigations which are directed on the development of scientifically-substantiated proposals for higher energy efficiency of the industry as a whole. It has become possible on the basis of the results obtained in the process of studying its power and heat engineering problems. The results of an analytical calculation analysis of statistical and obtained forecasting data are considered as a basis for the development of scientifically substantiated proposals for modernization of energy supply systems and power resource saving of the industry that fully corresponds to the investigation objective. The result of the executed investigations, that is a significant reduction of the energy component in the production costs will be presented in the follow-up publications.

The article presents solution for the task of evaluating exergy of the substance in the flow for textile and woven fabrics based on thermodynamic analysis of the corresponding technical systems. The exergy method allows estimating the energy effectiveness for the most problematic heat-technological systems of substance transformation and thus outlining the ways for decreasing the electric-power component in the production prime cost. The actuality of the issue stems from the renowned scenario alteration on the world energy market and is aggravated by necessity of retaining and building up the export potential of the light industry as an important component of the republic national-economic complex. The exergy method has been here for quite a long time and saw the interest fading and appearing again with periodicity of the research-generations alternation. Cooling down of every new generation towards the specified method is explained mostly by unresolved problem of the exergy evaluation for diverse materials, which poses a problem in the course of analysis of the substance transformation systems. The specified problem as a general rule does not create obstacles for energyconversion systems. However, the situation with substance-transformation systems is by far more complicated primarily due to diversity of the materials and respectively of the specification peculiarities of such component of the substance exergy in the flow as chemical component. Abeyance of conclusion in finding the chemical component of the substance exergy does not allow performing thermodynamic valuation of the energy provision for the heat-technological process in full measure. Which complicates the matters of decision-making and finding a medium for reduction of their energy consumption. All stated above relates to the textile industry and in the first instance to the finishing production departments.The authors present the exergy-evaluation problem solution for the substance in the flow for the most common fiber-types: natural animal and phytogenic ones as well as artificial fibers. Moreover, they present the solution for different colorants – basic, acid-type, dispersed. The paper considers the following components of substance exergy: reaction, concentration, and thermomechanical with presentation of their computation, correlation, and assessment deviation. The examples and exergy-computation results of the mentioned coloured fabrics are shown.

The paper proposes a technology for obtaining bricks on the basis of lime-silica mixtures where chemical interactions are practically completely realized in dispersive state at the stage of preparation of binding contact maturing and raw mixture as a whole. The role of forming operation (moulding) is changed in principle because in this case conversion of dispersive system into a rock-like solid occurs and due to this the solid obtains complete water-resistance in contact with water immediately after forming operation. Theoretical basis for the developed technology is capability of silicate dispersive substances (hydrated calcium silicate) to transit in non-stable state, to form a rock-like water-resistant solid in the moment of mechanical load application during forming process. Specific feature of the proposed method is an exclusion of additional operations for autoclaving of products from the process of obtaining a silicate brick.Synthetic hydrated calcium silicate in contrast to natural ones are more uniform in composition and structure, they contain less impurities and they are characterized by dispersive composition and due to the mentioned advantages they find wider practical application. Contact-condensation binders permit to manipulate product properties on their basis and ensure maximum correspondence to the requirements of the concrete application. Raw material sources for obtaining synthetic hydrated calcium silicates are practically un-limited because calcium-silicon containing substances are found as in various technogenic wastes so in natural compounds as well. So the problem for obtaining hydrated calcium silicates having contact-condensation ability for structure formation becomes more and more actual one. This transition is considered as dependent principally on arrangement rate of substance particles which determined the level of its instability.

Considers the current key energy problem – the rational and efficient use of energy resources, and the possibility of its solution, based on the concept of intensive energy conservation. As a result, the way of primary energy consumption reduction in Belarus is provided. The initial situation in the frame of program of further improvement of energy consumption until 2030 is estimated. It is shown, that for Belarus the first place in energy saving measures takes the efficiency improvement of natural gas consumption, what allows reducing the investment and saving energy resources.The possibility of usage of waste energy flows of medium-and low-temperature from industrial and municipal enterprises are discussed. To realize the described possibilities, some changes of heat supply system of enterprises and plants are required. Changes in heat supply system of the industrial enterprises, related with usage of low-temperature waste energy flows in a thermal energy generation process for heating, require the installation of additional equipment in existing heat energy supply system, such as absorption heat pumps, which are easily joint and successfully work at boiler Houses as well as at CHP. The numerous examples of fuel consumption reduction via heat industrial waste and sewage usage are shown in this article. It must be emphasized, that such an expansion of energy-saving framework not only reduce the primary energy consumption by heat generating sources, but also significantly improves the conditions of the Belarusian electrical grid operation under the conditions of nuclear power plant commissioning. The existing technical framework, that ensured the proposed changes, is also taking into account.

The development of methods for calculating the dynamics of the energy thermal characteristics of the accelerated hydration process is one of the most difficult tasks of heat power engineering. The article describes a new method of calculating the thermal characteristics of the process, focused on its application in the installations of accelerated hydration used for the production of 3D-reinforced concrete structures. The principles of cellular-automatic modeling of energy characteristics of concrete heat treatment process were used in the development of the method. The mathematical apparatus used in the method is based on the finite-difference three-dimensional heat equation, which allows taking into account, due to the system of boundary and initial conditions, the spatial dimensions of the concrete product, the spatial arrangement of the formwork, the spatial distribution of heating elements and other design features of the accelerated hydration system. The input parameters of the models used are the density, thermal conductivity, heat capacity of the concrete mixture and structural elements included in the tooling of the product. Boundary and initial conditions will make it possible to solve modeling problems for any 3D-design. The goal of the study is to develop a method for calculating the energy characteristics dynamics of the hardening of 3D-concrete products subjected to heat treatment, based on a grid non-equilibrium thermal model. The paper presents a mathematical equation apparatus that allows linking the geometric characteristics of the product and the finite-difference equations of thermal conductivity, including sources of heat. A numerical method for determining the energy characteristics of the hardening of 3D-concrete products subjected to heat treatment has been proposed consisting of, depending on the time of heat treatment, the calculation of the outside heat supplied to the concrete product, heat dissipated into the environment, the emitted heat of hydration and the heat accumulated in the concrete product during heat treatment, taking into account the geometry of the product. The method is based on a grid three-dimensional thermophysical model that takes into account the nonequilibrium and the system of boundary conditions that reflect the specifics of the process in the accelerated hydration of concrete. Calculations of the functions of the energy characteristics determining the heat treatment, depending on the time of heat treatment for cubic 3D-concrete products of different sizes have been performed. It is demonstrated that the rate of alteration of energy characteristics can be modeled for products of any spatial configuration.

Taking integrated power system of theRepublicofBelarusas an example the paper considers a possibility of heat accumulator use for TPP operation in accordance with the schedule of electric power consumption while maintaining daily supply of heat energy from turbine power takes-off and without involvement of peak-loader boilers used for covering energy loads.

The paper considers a decrease in consumption of natural gas by means of stabilization of the GTU power characteristics in summer when their degradation is observed due to higher ambient temperature and also the possibility to use an excess of thermal energy which occurs in a non-heating period for preservation of the GTU power and efficiency that provides sufficient economy of the initial fuel.

The paper considers a complex of measures directed on gross maximum realization of power saving potential while producing asphalt-concrete mixture.

The paper considers a creation of cogeneration complexes on the basis of the industrial heat technologies. The possibility of significant systematic decrease in need of primary energy resource has been shown.

The paper considers a new technology concerning the application of bitumen binder for production of asphalt concrete mixture. This technology radically changes the structure of asphalt and concrete production. The proposed technology has been elaborated in the process of modernization of thermal and power supply pertaining to asphalt concrete mixture production.

Determination of material exergy in a flow has been studied for asphalt concrete mix. Methodology for calculation of concentration component of asphalt concrete mix exergy has been proposed in the paper.

The possibility to utilize existing secondary energy resources for heat supply of an industrial enterprise has been proposed on the basis of the analysis on operation of compressor stations of a cross-country gas pipe-line. The paper considers an influence of waste heat recovery section on operational efficiency of gas turbine drive with regenerative heat utilization.

The paper considers complex approach to power technological modernization of asphalt concrete mix production. This modernization radically changes structure of asphalt concrete production.

The paper considers a potential, energy and economic efficiency of joint activities of enterprises of the Ministry of Energy sector and enterprises of the material sector of the economic complex of the Republic of Belarus on the basis of the methodology for intensive energy saving. Such calculated values as annual savings of natural gas in Belarus – up to 1 million tons of fuel equivalent, release investment for the Ministry of Energy – up to 1 billion USD, range for changes in electricity generation during a day - up to 1 GW with a specific consumption of fuel equivalent – 160 g/(kWh) have been determined while taking thermal technology of asphalt concrete mixture production and regulation of electricity generation as an example. Fuel saving system and investment return create preconditions for realization of the project by private investors.

The paper considers potential of power saving by the Belarusian industrial enterprises at transition to cogeneration power supply of heat technological processes.

The paper considers a potential of power saving at enterprises of consumer industry in theRepublicofBelaruswhile making transition to co-generation power supply of heat technological processes.

The paper presents test results of asphalt concrete samples which have been obtained with the help of new technology. In accordance with this technology new bitumen binder modified by polymer admixture which has made it possible to capsule bitumen in shell.