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Recently, many problems, such as the energy crisis and environmental pollution, have made the use of alternative energy in the production of electrical and thermal energy relevant. Because alternative energy sources are environmentally friendly, accessible and inexhaustible. In the most advanced and developed countries, heat pump systems are used for heating, ventilation and cooling of buildings. The article examines the efficiency of operating modes of collector-type geothermal heat pumps in the Karabakh economic zone. The heat supply scheme and all characteristic parameters associated with this scheme were calculated using the GeoTSol modeling program. The GeoTSol simulation program is one of the modern simulation programs for planning and designing heat pump systems. As an example, a private residential building located in the city of Khojavend was studied. A monovalent collector-type heat pump system provides hot water supply and heating for a private home. For comparison, a diagram of 4 types of collector-type heat pump systems is proposed. Seasonal performance coefficients, energy consumption, losses, solar energy share, efficiency, etc. were calculated by computer simulation of the entire heat pump system for each cycle and compared with each other. A circuit operating in the most efficient mode has been determined. [ABSTRACT FROM AUTHOR]

Automation of industrial heat supply points using serial domestic automatic regulators, sensors, microprocessor devices and computer programs is considered. A technological scheme for automating an open heat supply system of an enterprise with a corrective mixing pump and a network water flow regulator are developed. [ABSTRACT FROM AUTHOR]

To design and analyze structures and materials that are subjected to changing thermal environments, it is essential to take into account thermal shock events, which are characterized by rapid and dramatic changes in temperature. In this study, a new thermal conductivity model was used to consider the thermal response of an isotropic thermoelastic medium heated by a moving heat source. This model uses memory-dependent higher derivatives and the concept of the Moore–Gibson–Thompson equation. Using the vector-matrix differential equation form, the basic equations are formulated. The model was applied to consider the thermomechanical behavior of a semi-infinite thermoelastic solid. In the field of the Laplace transform, the technique known as the eigenvalue approach deals with the mathematical formulation and solution of the problem. The inversions of Laplace transforms are found numerically using the Honig and Hirdes approximation approach. A graphical representation is provided showing the fluctuation in temperature, displacement, and stress distributions with changing values of kernel functions and higher orders, as well as the velocity of the heat source. Tables are also included to show comparisons and a full analysis of thermomechanical responses and how they affect the way system variables behave. [ABSTRACT FROM AUTHOR]

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The article presents the scientific results of a study assessing agroclimatic resources in agricultural landscapes located in various natural zones of the Turkestan region of the RK (Republic of Kazakhstan). The research methods included classical and modern methods of mathematical statistics using digital technology and time series graphs to develop a mathematical model for climatic and hydrological indicators. Assessment of changes in indicators of agroclimatic resources in agricultural landscapes for 1941-2020 showed that the sum of air temperature, evaporation from the water surface and radiation balance of the daytime surface, characterising the energy resources of landscapes, increased by 10-15%, which contributes to increase in the total water consumption of agricultural land by 10-12%. Meanwhile, the decreasing tendency of the amount of precipitation by 5-10% in all natural climatic zones of the region has become one of the factors leading to a decrease in the natural moisture supply of the soil and vegetation cover of landscapes by 10-15%, acting as important environment-forming and ecological functions. The combined impact of these environment-forming factors has become the key reason for the increase in the deficit of agricultural land water consumption by 15-20%, the reduction of solar energy costs for the soil-forming process by 10-15% and the increase of the climate aridisation, and has become a signal for the need in the safety of agricultural activities, requiring the development of a set of adaptive measures to mitigate this process in the region. [ABSTRACT FROM AUTHOR]

In the process of solving the tasks of extracting low-potential environmental heat from open bodies of water when using heat pump systems with collectors immersed in the body of water, there is a need to obtain information about the depth of temperature changes in the body of water, which determines the layer of water that actively interacts with the Earth's atmosphere. In the cold season, the temperature in it drops, and in the warm season it rises. It is known that the efficiency of the heat pump system depends on both the temperature difference at the outlet of the heat pump condenser and the inlet to its evaporator, and the stability of the temperature of the heat energy source. The temperature at the inlet to the heat pump evaporator is determined by the temperature of the medium at the place of installation of the thermal energy collector. And taking into account the fact that the collector of the hydrothermal system usually sinks to the bottom of the reservoir, the task of determining not so much the change in water temperature in the reservoir itself as the temperature at the watersoil boundary, at the bottom of the reservoir, that is, the study of thermo physical processes occurring in water under the influence of both exogenous and and endogenous factors. The main feature of the hydrothermal thermal energy production system is the combination of technical and natural elements of such systems. At the same time, the natural source of thermal energy is located in an environment that is not easily accessible for observation. The paper provides a description of the developed experimental hydrothermal heat pump system and the research methodology. Field studies were conducted to analyze the influence of bottom heat flows on the daily regime of a small open water body. Changes in the temperature of water and the bottom of open water bodies in the city where the experimental system is located are practically determined. It is shown that as a result of taking into account the heat exchange with the bottom, the temperature at the depth of the reservoir increases and decreases near the surface. This leads to an increase in the turbulent flow from the atmosphere and a decrease in heat output due to long-wave radiation, as a result of which the average temperature of the reservoir increases. The mathematical apparatus for analytical calculation of the depth of temperature wave propagation in water during the construction of hydrothermal heat pump systems is described. The basic mathematical apparatus for describing such processes includes differential equations that take into account the dependence of temperature on time and spatial coordinates. [ABSTRACT FROM AUTHOR]

Depletion of the world's fuel and energy resources, which causes an inevitable increase in energy prices, both on the world market and in Ukraine, has exacerbated the problem of the introduction of energysaving technologies and put research aimed at the effective use of renewable energy sources for the purposes of energy supply into a number of strategic tasks state. The paper analyzes existing heat supply systems and ways to increase the efficiency of using existing energy resources and reduce emissions of harmful substances into the environment. The expediency of a comprehensive approach to the implementation of energy-efficient technologies in the heat supply system, taking into account the peculiarities of the operating modes of buildings and engineering life support systems, is shown. Based on the analysis of existing mathematical models and methods of calculating the operating modes of various elements of the combined heat supply system using renewable energy sources (solar collectors, heat pumps, heat accumulators, etc.), mathematical models of the operating modes of the specified systems are given. On the example of a separate building of public purpose (educational building), the calculation of the operation modes of the microclimate engineering systems was carried out taking into account the operating modes of the building, and on the basis of the available pilot plant, a study of the operation of the combined heat supply system using renewable energy sources and the use of heat accumulators was carried out to coordinate the generation modes and heat consumption by the building. On the basis of the conducted research, the distribution of the shares of energy savings from each stage of modernization of microclimate engineering systems and general thermal modernization of the building using both external thermal insulation and internal shielding of massive walls was obtained. [ABSTRACT FROM AUTHOR]

Copyright of Deutsches Institut für Wirtschaftsforschung: DIW-Wochenbericht is the property of DIW Berlin and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper considers the use of exhaust gas heat in modular power plants. In this regard, fuel consumption at power plants will decrease, efficiency of power plant will increase the emission of harmful gases into the atmosphere and environmental burden will reduce. [ABSTRACT FROM AUTHOR]

Energy sources and mechanisms supplying energy to the oscillating system of an ejector pulsejet engine that supports gas acoustic self-oscillations, are researched. The study is carried out using experimental, numerical, and analytical methods. [ABSTRACT FROM AUTHOR]

Copyright of Renewable Energy / Vidnovluvana Energetyka is the property of Institute of Renewable Energy of NAS of Ukraine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The work analytically investigates a new recuperative-transformer system with subcooling of the recirculation flow of furnace cooling, which increases the heat-technological and energy efficiency of furnace units, expanding the technical and economic efficiency of industrial heat supply. The basis of the research is the conclusion that the application of heat pump technologies for energy saving in the production of building materials in rotating furnaces with the utilization of low-temperature gas-air flows is very promising. It is noted that the stabilization of the thermal mode of furnace cooling during the year is an important technical and economic task aimed at improving the thermal process and energy saving, primarily for the firing zone. An analytical study of the recuperative transformer system with subcooling of the recirculation flow was conducted. The equation of the heat balance of the heat extraction system of the gas-air circuit in the process of furnace cooling is presented. The transfer of heat absorbed from the surface of the furnace in recuperative heat exchangers, as well as in the evaporator of the thermotransformer circuit of the vapor compression heat pump is described. A generalized dependence was obtained for the heat flow of furnace cooling and a low-potential source in the gas-air circulation circuit of the heat supply system. The dependence for the real conversion factor is determined. A graphical interpretation of the dependence of the effective conversion factor on the ratio of the consumption of the heating medium and the heated medium is presented. It is emphasized that the results of the study of the rational interrelationship of the initial and mode parameters create a basis for the engineering development of the proposed heat supply systems based on the stabilizing cooling of the rotating furnace. [ABSTRACT FROM AUTHOR]

It is found that the problem of boundary layer stability with a diffusion flame under the conditions of a constant molecular weight over the boundary layer in the inviscid approximation and in the Dunn–Lin approximation with identical Schmidt numbers can be reduced to a similar problem for a single-component gas. Approximately, this conclusion is also valid for different Schmidt numbers. Calculations of the steady-state parameters of the boundary layer show that there are two generalized inflection points testifying to a necessary condition of the "inviscid" Rayleigh instability. Simulations show that the boundary layer with a diffusion flame is most unstable to two-dimensional disturbances. As the frequency is increased, the phase velocity of the growing wave tends to the value at the generalized inflection point. Despite sufficiently large growth rates, the degree of spatial enhancement of the wave is equal with high accuracy to the ratio of the time degree of enhancement to the group velocity. [ABSTRACT FROM AUTHOR]

Observations of the Earth climate for the last 100−150 years have revealed that the atmospheric air temperature in the ground level shows quite a rapid growth. Megalopolises and other settlements behave as large sources producing thermal pollution of the Earth air basin. Transport facilities, heated buildings, and heat and electric networks release a significant amount of energy, which accumulates in the air medium of cities and then dissipates into the surrounding space. The most rapid change in the air temperature has been noted for the last 50 years. The greatest increase of the outdoor air temperature, e.g., in St. Petersburg, is observed in the cold period of the year. It has been determined that the average air temperature in the cold period of the year (from October to April) has increased by 1.51°С, whereas the average air temperature increased by 0.72°С for the same interval of time but in the warm period of the year (from May to September), i.e., half as much as in the cold period. It has been found from studies of regulatory and reference documents that the standard climatic data specified in them lag significantly from the currently occurring climate changes. The article presents an analysis of the outdoor air temperatures in St. Petersburg for the period from 1992 to 2021 and an assessment of air temperatures in the coldest day and the coldest 5-day spell with reliabilities of 0.92 and 0.98 and also the absolute minimal air temperature for the considered 30-year interval of time. It is pointed out that the actual climatic indicators derived from statistical processing of daily data arrays are by 3–4°С higher than those specified in the relevant standards. As a result, when buildings are designed for the standard conditions specified by the existing regulations, the contractual loads turn out to be overestimated essentially in comparison with the actual ones, which is revealed in designing the configurations of settlement heat-supply systems. The consideration of actual climatic indicators opens up the possibility to decrease the contractual heat loads of consumers on a sound basis and, as a consequence, to achieve thermal energy saving without degrading the heat-supply quality. [ABSTRACT FROM AUTHOR]

An urgent task in the design of complex local energy supply systems (cluster) using renewable energy sources (RES) is to take into account the experience of operating specific types of equipment in real conditions. The paper considers the possibility of effective use as an element of the energy cluster of the buffer storage system of the heat pump system as a thermal energy accumulator to provide multi-purpose objects with thermal energy. The buffer storage is a part of the low-capacity system for obtaining heat energy, which is part of the general system (unit), which consists of a buffer storage of the heat carrier, a heat pump and fan coils. The structural diagram of the energy cluster and the place of the low-capacity thermal energy production system in it are given. The working layout of the experimental hydrothermal heat pump system developed and constructed at the Institute of Renewable Energy of the National Academy of Sciences of Ukraine, which includes a buffer storage device, is presented. The research methodology is described. The characteristics of the measuring equipment installed on the experimental setup, which was used to obtain data in the process of conducting research, are given. The results of research work, obtained in the course of theoretical calculations and conducted experimental studies of the effectiveness of the buffer storage of the hydrothermal heat pump system as a thermal energy accumulator, are outlined. The calculation of the conversion factor of the "water-to-water" heat pump in the heating system of a room with an area of up to 100 m2 with the use of fan coils and buffer storage of thermal energy of different capacities is given. The calculation of the required volume of the heat carrier and the capacity of the buffer storage, per one kilowatt of produced thermal energy, was performed to ensure the autonomous operation of the heat pump system, where it performs the function of a battery and a collector of thermal energy at the same time. A sufficient volume of coolant and battery capacity per kilowatt of thermal energy produced by the heat pump to ensure stable operation of the hydrothermal heat pump system as a whole was determined. It has been experimentally confirmed and theoretically substantiated that the buffer storage of the heat pump system is a necessary element of the system, it performs both the function of a shock absorber and significantly increases the efficiency of the heat pump system as a whole. Including the buffer storage device, depending on the thermal load, it can work independently as an autonomous source of low-potential thermal energy. Conclusions were made that further research on the possibility of use as a source to maintain the necessary energy potential in the buffer storage of the heat pump system, the solar system for heating water, has a perspective. But it is relevant to carry out research on the comparison of the efficiency of the complex operation of the solar system for heating water and the heat pump, where the heat exchange takes place: first, in the circuit of the evaporator of the heat pump; secondly, in the circuit of the condenser of the heat pump. The work was carried out as part of the scientific research work: "Development of energy clusters to provide multi-purpose objects with electric and thermal energy using renewable and hydrogen energy technologies (code: "Energy-guarantor")" [ABSTRACT FROM AUTHOR]

Methane hydrates found in the sediments of deep sea and permafrost regions draw global interest. The rate of gas production from a depressurized well is governed by the effective permeability of the hydrate-bearing sediments around the wellbore. During depressurization, a decrease in pore pressure leading to soil compaction and hydrate dissociation results in a dynamic change in the effective permeability. To describe the change in the effective permeability in detail, in this study, a simple coupled compressibility–permeability analysis method is proposed to identify the conditions under which the effective permeability increases or decreases after depressurization. An analytical solution is derived for the effective permeability change with pore pressure and temperature, considering hydrate dissociation and soil compaction. We found that when there is a sufficient heat supply, hydrate dissociation dominates the effective permeability during hydrate dissociation, but after hydrate dissociation, soil compaction is the governing factor for permeability change. When there is an insufficient heat supply, however, compaction mainly determines the permeability, and the effect of hydrate dissociation is limited. This work will be helpful for rapid reservoir assessment. [ABSTRACT FROM AUTHOR]

Energy efficiency is one of the critical areas of ensuring sustainable development. One of the promising technologies in this context is heat pump technology for heat supply. Such technologies have been widely implemented in the EU for several decades. At the same time, very few projects with powerful heat pumps have been implemented in Ukraine, which is explained by their high cost. However, given the current energy resource prices, Ukraine's heat pumps are already becoming competitive. The paper examines the Levelized cost of heat energy from systems with heat pumps of the "soil-water" and "air-water" types and a gas boiler house at various discount rates and prices for electricity and natural gas. It is shown that domestically produced ground source heat pumps are primarily competitive. [ABSTRACT FROM AUTHOR]

The problem of stability of a subsonic boundary layer is solved under the conditions of heat supply inside the boundary layer with injection of a homogeneous gas through a porous plate that partially simulates the problem of stability of a boundary layer with diffuse combustion. Two-dimensional waves are the most growing waves over the entire range of investigated parameters. It is found that in the case of a fixed norm of heat supply the maximum temperature in the boundary layer increases with the Reynolds number, i.e., with increase in the distance from the leading plate edge. This is in agreement with available experiments and calculations of parameters of the boundary layer with diffuse combustion. In this case the dependence of the degrees of amplification on the Reynolds number, which are maximum in the frequency, is nonmonotonic. It is shown that gas injection with heat supply destabilizes the boundary layer, as it occurs without heat supply. On the other hand, the stabilizing role of heat supply is also shown under the conditions of gas injection through a porous wall. As the frequency of growing wave increases, the phase velocity tends to the velocity at the generalized inflection point. Despite fairly large degrees of growing, the Gaster relation is valid. In accordance with this relation the spatial degree of amplification is equal to the temporal degree of amplification divided by the group velocity. [ABSTRACT FROM AUTHOR]

The use of solar energy in current conditions is one of the most affordable and popular energy-saving technologies that allows to significantly increase the efficiency of heat supply due to the fact that the energy obtained from the Sun is the cheapest and technologically available. The work considers the issue of using solar heat supply systems for heating needs of private houses, office premises and industrial premises. A classification of existing types of solar collectors is provided. A general analysis of the construction, principle of operation and composition of flat and vacuum solar collectors is given. The main thermophysical parameters that determine the efficiency of the solar system are substantiated. An analysis of the efficiency of flat and vacuum solar collectors for heating water in the hot water supply and heating system of buildings was performed. A patent search and systematized innovative solutions that increase the efficiency of the solar system have been conducted. General shortcomings of all heliosystem designs and directions of efforts of inventors are established. It is concluded that in order to improve the efficiency of solar heat conversion systems, work algorithms and high-quality adjustment of control controllers and their use by regulators must play a significant role. Their main function is to control the thermophysical parameters of the heliosystem and automatically make a decision on the control of electronic valves in order to ensure the optimal temperature of the coolant in all circuits. It is justified that further research into the implementation of multi-circuit systems for obtaining thermal energy from solar radiation in combination with other sources of obtaining thermal energy and an effective system for accumulating the received heat has a perspective. [ABSTRACT FROM AUTHOR]

An increase in the share of renewables in heat supply systems is a promising direction to reach sustainable development goals and decarbonization. Decision makers should consider various factors, including energy market prices, the availability of biofuels, boiler and auxiliary equipment costs, logistic costs, and the taxation system. In the European Union, the energy crisis causes a rapid increase in fossil fuel prices. Moreover, the use of fossil fuels results in greenhouse gas emissions, which threatens the achievement of sustainable development goals. We studied the influence of the delivery cost and the value of environmental tax rates on the levelized cost of heat. Low-capacity boilers (up to 1 MW) and different fossil and renewable fuels were analyzed. An analysis was carried out on the example of Ukraine. The European trends were factored in. The obtained results showed that biofuel boilers had lower levelized costs of heat than fossil fuel boilers. Delivery costs and environmental taxes have a significant impact on heat energy costs. [ABSTRACT FROM AUTHOR]

The purpose of the article is to substantiate the feasibility of an integrated approach to the implementation of measures for the restoration and modernization of housing stock and heat supply objects. On the conditional example of heat supply of a heated quarter (which means a small number of residential buildings to be heated, a local boiler room and local distribution heat networks), various modernization options are considered: separate thermal modernization of buildings, modernization of heating networks, modernization of the boiler room, and options for simultaneous modernization of all elements of the chain: production-supply-consumption of heat energy (complex modernization of the heated district). It is proved that precisely a comprehensive modernization, which involves a simultaneous production, coordinated in terms of time and volumes, supply and consumption of heat, is an effective instrument for improving efficiency in the sphere of heat supply and heat consumption. The complexity of modernization in this example involves thermal modernization of buildings in the heated district (with a decrease in heat consumption by 40%) with the simultaneous modernization of heat transmission networks (with a decrease in heat loss when supplied from 20% to 5%) and modernization of the boiler room (with an increase in the efficiency quotient of boiler equipment from 88% to 93%). The implementation of such a project is economically feasible for all participants: consumers reduce the cost of paying for heat supply services by 49%, and the supplier and producer of heat with a slight (up to 6%) increase in heating tariffs provide break-even activities and receive a larger investment resource in the form of a larger amount of depreciation. At the national level, the proposed mass complex modernization of heated districts can almost halve the consumption of natural gas by municipal heat and power engineering and to the same extent reduce emissions of harmful substances into the atmosphere. In addition, it becomes possible to significantly reduce the amount of subsidies from the budget for the payment of housing and communal services by the population. [ABSTRACT FROM AUTHOR]

The aim of the study is to define the essential characteristics of startups, identify the features, trends and prospects for their development in the global energy sector as well as development opportunities in Ukraine. Based on the carried out research, it is shown that today startups are a catalyst for economic development, the processes of their creation in the world are developing dynamically. The importance of the energy sector in the development of startups due to the importance for states and humanity aiming at achieving the goals of the transition to clean energy, also the need to ensure energy independence and security of the countries of the world, and their national security in particular, is determined. An understanding of the essence of the concept of «startup» has been formed. It is found that startups are based on low-tech, high-tech and deep-tech innovations, their features are examined. Specific features of the energy sector that determine the processes of technological changes in the sector and affect the peculiarities of creating and implementing startups, the dynamics of their development and risks are highlighted. Quantitative indicators of the development of startups (including those connected with energy sector), as at the global level so by individual countries, their structure according to the directions, features of the development of startups in the fields of «clean» and «digital» energy are researched. The experience of individual countries in building an effective startup ecosystem is considered. It is substantiated that in the current conditions the development of the country requires the use of various instruments on the part of national policy for the formation and development of an ecosystem of startups, ensuring the appropriate institutional environment. This will create the basis for economic growth, which is extremely important for Ukraine in the context of post-war economic recovery. It is determined that large-scale destruction in the energy sector substantiates the high importance of the development of startups in it, which can be helpful in covering certain needs, for example, in liquid fuel, efficient heat supply, etc. [ABSTRACT FROM AUTHOR]

The paper presents a model of a solid fuel boiler with the improvement of the locking mechanism to increase its efficiency, which in turn will increase the savings and ecological safety of such a boiler. The given calculation of the volume of dry gases, theoretical volume of nitrogen and the volume of water vapor, which makes it possible to determine the content of oxygen in the air and other elements in the fuel. Given a 3-D model of solid fuel boiler by means of FlowSimulation software. Based on the test results, the amount of combustion products leaving the chamber was shown. The research results show that, depending on the size of the boiler elements, there is no ventilation in the room where the boiler is located, and after an hour of operation, a long stay of a person may cause health problems. t has been shown that the excess air factor depends on the type of combustible fuel, the method of its combustion and the structure of the boiler combustion chamber. A construction of the closing mechanism of the combustion chamber of a solid fuel boiler is proposed. Based on experimental and computational research, a model of the boiler door handle was constructed, when automatic opening would be impossible. Such a design of the mechanism closing the combustion chamber of a solid fuel boiler allows to increase its efficiency as a result of the stability of the gas mixture composition and to reduce the risk of carbon monoxide falling into the room. [ABSTRACT FROM AUTHOR]

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This article considers a wide range of issues concerning the heat supply system in Novosibirsk Oblast and the Russian Federation as a whole. Concession agreements can be used as a tool to increase the efficiency and reliability of the heat supply, especially in population centers that are not attractive for large energy companies. Concession agreements also have their drawbacks. Based on a study of concessions in the Novosibirsk heat supply industry and interviews conducted with the initiators and participants of such projects, we describe the preliminary results and related problems of such concession agreements. In our study, we consider the use of concessions to modernize district heating systems in the urban type of settlement of Maslyanino and the town of Ob. The preliminary results of these projects showed that federal and regional budgetary investment made it possible to greatly reduce the subsidization of heat supply organizations. However, the possibility of replicating these results is limited due to a number of institutional and economic factors. The greatest risks for potential concessionaires are associated with tariff regulation based on "economically justified costs" and the high transaction cost of privatizing the district heating systems formerly operated by municipal unitary enterprises. We argue in favor of new mechanisms for financing concessions in the heat supply industry. These can significantly increase the attractiveness of such projects for private investors and reduce the need for regional and local budgets to subsidize unprofitable heat supply organizations. [ABSTRACT FROM AUTHOR]

As part of the long tradition of EKO, we try to supplement the work of academic researchers with that of experts working in the field. This set of articles concerns the challenges facing the Russian heat supply system. We have asked S.V. Bukharov, a representative of the energy sector, to take part in the discussion. S.V. Bukharov has more than 15 years of experience in the financial and economic management of the energy sector (including with the Novosibirskenergo group, OJSC TGK-13, and the Association NP Market Council et al.). As a consultant, S.V. Bukharov has helped prepare materials for an appeal to the Russian government to classify the urban-type settlement of Linyovo (Iskitimsky District, Novosibirsk Oblast) as a heat supply price zone. This article describes the possible effects for the industry and consumers resulting from the transition to the "alternative boiler plant" model, including a description of the mechanisms for equalizing the price effects for consumers after the transition. S.V. Bukharov concludes by providing an assessment of the applicability of the new alternative boiler plant method. [ABSTRACT FROM AUTHOR]

The article discusses several models and methods for managing the supply of heat to consumers inside a market economy. The main organizational forms of heating systems are described via the models of a "unified heat supply organization" and a "single buyer," which can be implemented in the population centers of the Russian Federation. We offer an analysis of various types of competition in the thermal energy market and describe the effects that can be achieved when they are implemented. Based on the example of Russia's large district heating systems, we show the negative consequences resulting from the introduction of the "alternative boiler plant" method, which is a new target model for the Russian thermal energy market. [ABSTRACT FROM AUTHOR]

A rational explanation of the reasons for the widespread practice of significant noncompliance with the design values of the temperature of mains water and coolant in heating devices in cold periods of the year is given. The process of forming the design load of heating systems is analyzed. It is shown that the term in the heating load, due to the heating of the supply air, should take into account different modes of operation of the premises during the day. Failure to take this fact into account leads to an overestimation of the design load of heating and all parts of the heat-supply system by up to 30%. The modes of operation of heat-supply systems with dependent connection of heating systems with elevator mixing and with their independent connection through heat exchangers at low temperatures of direct mains' water are considered. It is shown that it is possible under these conditions, with proper consideration of the standard average daily air exchange of premises for existing heat-supply systems, to switch to a reduced temperature schedule. For an overestimated estimated capacity of heat losses of buildings by 30% while maintaining high-quality regulation, examples of switching to a temperature schedule of 114–58°C for a heating system with both elevator mixing and with its independent connection to the heating network are given. [ABSTRACT FROM AUTHOR]

The issue of using heat pumps for the needs of autonomous heat supply of private houses, office premises and produc- tion premises is considered. The analysis of efficiency of work of the compression heat pump with fan coil for heat supply of buildings is given. The current model of the experimental heat pump system developed and constructed in IVE of NASU is presented. The method of conducting research is described. The characteristics of the measuring equipment installed on the experimental setup, which was used to obtain data in the process of research, are given. The results of scientific work obtained in the course of theoretical calculations and experimental studies of the efficiency of the heat pump system are presented. The conversion factor of the air-to-water heat pump in the heating system of a residential building with an area of up to 100 m is calculated. The dependences of the heat pump transformation coefficient on the type of renewable source of low-potential heat energy are given. The dependences of the efficiency of the heat pump system on the parameters of the primary source of low-potential heat and design features of the heat supply system are substantiated. It has been experimentally confirmed and theoretically substantiated that the fan coil is an effective space heating device when working in conjunction with a heat pump. It is substantiated that further studies of heat pump systems implementation are promising, where low-potential energy of natural surface layers of the Earth and water of open reservoirs and aquifers and improvement of heat extraction systems from low-potential renewable energy sources are used as primary sources. [ABSTRACT FROM AUTHOR]

An assessment of the wind potential in the western sector of Russia's arctic zone is given, which testifies that there is high wind intensity in the Barents Sea and White Sea coastal regions. According to the meteorological stations data, the annual average wind velocities in this zone are in the range from 5 to 8 m/s at a height of around 10 m, which is an obvious prerequisite for using windmills in the power and heat-supply systems of remotely located consumers in the north. Another important prerequisite is that there is a winter maximum of wind intensity, which coincides with the winter maximum of energy demand for space heating needs. This helps incorporate the wind energy into the space heating load schedule, decrease the heating boiler house operation time, and achieve essential fuel saving. Based on the results from synchronous observations of the outdoor air temperature and wind velocity in the Kola Peninsula's northern coast, which determine the heat consumption amounts, the annual heating load schedule of coastal consumers is considered, and the possible participation of a boiler house and windmills in covering this schedule is shown. Based on the study results, it has been evaluated whether it is feasible to supplement the heat-supply scheme with heat accumulators that can store energy surpluses in the strong wind periods and then produce them, in the periods of low wind power, for covering the heating load schedule, as necessary. The incorporation of heat accumulators makes it possible to utilize the wind energy to a fuller extent, to minimize its idle rejections, decrease the boiler house operation time, and achieve lower fuel consumption and operation costs. [ABSTRACT FROM AUTHOR]

The article considers the main factors influencing the annual economic gain from decreasing the payment for the water use by a thermal power plant (TPP) in the case of applying heat pumps in the steam turbine condenser cooling system. For the conditions of Russia, an expected variation range of tax rates for withdrawal of water resources from a source is established depending on the TPP service cooling water system's location and type, and the potential decrease in the amounts of water use by a TPP is determined. With reference to combined cycle technologies, the maximal power capacity of the heat pump that can be installed at a combined cycle TPP is estimated subject to the condition of plant lossless operation in the Russian wholesale market of electricity and power. A tentative variation range of the heat pump unit's operation time in using thermal energy both in the TPP production processes and for heating purposes is estimated. For the conditions of Russia, the territorial distribution of the maximal expected economic gain from decreased amounts of water use owing to heat pump application in the TPP condenser cooling system is estimated. The effect the economic gain obtained from decreasing the amounts of water use has on the key indicators of an investment project on introducing a heat power unit with a thermal capacity of 50 MW at a TPP under the conditions of St. Petersburg is analyzed for different service cooling water-supply systems. The integral economic gain obtained from decreasing the amounts of water use in implementing such a project for the entire service life of the heat pump used as part of the TPP equipment is expected to be 182.7 million rubles with a once-through water-supply system, 2.6 million rubles with a circulation water system with a cooling tower, and 2.0 million rubles with a circulation water system with a pond. [ABSTRACT FROM AUTHOR]

An analysis of the contractual loads of heat-consumption objects connected to one of the boiler houses of the Fuel and Energy Complex of St. Petersburg is presented. The analysis was carried out on the basis of the results of processing the readings of heat-metering devices installed at the subscriber inputs of apartment buildings located on the territory of St. Petersburg. The analysis was carried out of the consumption of heat energy for heating during the heating period of 2018/2019, and a comparison was made of the calculated and contractual loads of heat-consumption objects located in the area of operation of the considered source of heat energy. Change in the specific indicators of thermal energy in apartment buildings for heating depending on the series/types of buildings, their number of stories (taking into account the number of entrances), construction periods, and their heated area is shown. Examples of determining the calculated heat load for heating- and hot-water supply of heat-consumption objects according to the data array of general house heat meters, including within the schedule for regulating the supply of heat at the source. The coefficients showing the ratio of the calculated heat load of heat consumption subscribers to the contractual load were obtained. The reserve of thermal power for existing consumers of thermal energy and the source to which these consumers are connected has been identified. The average value of the coefficient, which is the ratio of the calculated heat load for heating to the contractual one, is 0.66, the averaged value of the coefficient, which is the ratio of the calculated heat load for hot-water supply to the contractual one, is 0.82. [ABSTRACT FROM AUTHOR]

A description of the energy-saving technology for the generation of electrical energy is presented in the superstructure of steam boiler houses with turbine-generator units (TGU) with backpressure turbines operating in parallel with reduction cooling units. The characteristics and description of a TGU for distributed energy, developed at OAO KTW, with backpressure turbines and condensing turbines with and without steam extraction, surface and air condensers, and mini-CHPP with built-in boilers for heating network water are given. TGUs are described for geothermal energy with turbine exhaust to the atmosphere or to a heat-supply station with condensing turbines with air condensers. The technical characteristics of TGUs of various types, the number of units produced, and the place of their operation are given. The design features of TGUs manufactured at OAO KTW are noted: block layout, 100% factory readiness, high degree of automation, and reliability during operation. Prospects for further developing the direction of turbine-generator sets for distributed energy are shown: development and delivery of condensing and backpressure turbine-generating sets with a capacity increased to 8 MW; expanding the range of a "connected-in" TGU operating on steam from the extraction or exhaust of the main turbines, which make it possible to compensate for seasonal or technological fluctuations in heat energy consumption and ensure more efficient operation of the main turbines; and development of binary plants using low-grade heat and operating on low-boiling organic heat carriers. High efficiency of distributed power generation in combination with cogeneration is noted. [ABSTRACT FROM AUTHOR]

In production and in everyday life, various heating systems are used. Alternative heating methods have also been used in recent years. One of the sources for the heating system is the Sun. The use of solar energy is of great importance for objects cut off from centralized heat and power supply systems: small villages and auls, farm formations, distant pasture breeding, mobile houses. Heating from the sun, created on the basis of solar panels, is carried out by installing an electric heater. Currently, more and more attention of consumers is drawn to the electrically conductive carbon-based fuel material (carbon). The aim of the study was to study the use of an alternative energy source in the form of solar radiation and carbon thermal flexible material as a heater for heating mobile living quarters of farmers. To carry out the research, a solar station and a heater with a carbon fiber heat-emitting flexible material were installed on the farmer's mobile house. Studies have shown that the proposed system is efficient and in comparison with other systems, such as solar collectors, the system has a number of advantages. [ABSTRACT FROM AUTHOR]

The paper presents a study of a supersonic boundary layer while heat supply to the layer's narrow internal region. Calculations were performed for a flow with Mach number M = 2 and the dimensionless temperature (normalized to the temperature at a layer boundary edge Tw = 3.9 (630 K). It was demonstrated that heat supply causes a twofold increase in the 2D disturbance increments, while the frequency range expands by factor of three with a heat-insulated plate (zero heat input) taken as a reference. For a heated plate (with Tw = 3.9), the heat input into this layer delays the disturbance growth; that is, this facilitates the boundary layer stabilization and the disturbance increments reduce by almost four times. Along with 2D waves, the oblique waves were investigated in this paper. It was found that for low-frequency disturbance, we observe an intense growth of 3D (oblique) waves. Meanwhile, 2D disturbances enhance for a high-frequency range. These facts comply with the numerous data on boundary layer stability. However, these factors for boundary layer stability become less significant in the case of heat input to the supersonic boundary layer (compared with the zero heat input). The study also observes the longitudinal structures with a downstream decay. The heat supply makes these structures decrement lower in the supersonic boundary layer (meaning a slower decay). The results for the study of boundary layer disturbance are compared to similar data for the flow with M ≪ 1. [ABSTRACT FROM AUTHOR]

In modern realities, developing the centralized heat-supply system in Russia is associated with a constant search for reserves for saving heat energy, its rational use, and a constant increase in the reliability and energy efficiency of heat supply to consumers. The solution to the problem of increasing the reliability of the operation of heating networks and maintaining their operability and durability is not limited to the replacement, reconstruction, and modernization of actually worn out, emergency, sections of heating networks that have not passed hydraulic tests. It is equally important during the operation of pipelines to maintain the regulatory conditions that determine their durability. The statistically most significant reason for the failure of heating networks is external corrosion of the metal, which, in turn, is most often caused by the pipe being in a humid environment or simply in water when the channel is flooded. The paper considers the possibility of increasing the reliability of heating networks by timely detection of deviations from the standard of the actual operating conditions of the heating network sections, which are in a humid environment that intensifies the processes of external metal corrosion. The rapid growth in the number of thermal energy meters installed at the facilities of district heating networks and facilities for consumers of thermal energy, together with the use of modern measuring instruments and systems for remote transmission of meter readings, creates the prerequisites for the development of a software product. It is proposed to use a software product that analyzes the operating conditions of heating networks in real time and notifies about their deviation from the standard values. A technique has been developed for the automated calculation of the coolant temperature's standard values. [ABSTRACT FROM AUTHOR]

To solve the problems of saving thermal energy, instead of the currently used cumbersome methods or complex mathematical models, for example, in the form of partial differential equations, it is proposed to use simpler models of time series for the supply and production of thermal energy. The data of a specific heat supply organization on a city scale and the website of the Ministry of Energy of the Russian Federation were used as initial data. The proposed approach is based on a comparison of various mathematical models for predicting the production and supply of heat energy according to the criterion of adequacy (average relative error and coefficient of determination). The results of research carried out using the Matlab software package are presented. A substantiated comparison of the possibility of using different models is carried out. Models have been developed that take into account the seasonal component and higher accuracy. The possibility of using the following time series models is investigated: regression models with a seasonal component, triple exponential smoothing Holt–Winters, multiplicative seasonal autoregression model of the integrated moving average SARIMA (seasonal autoregression integrated moving average), and nonparametric model SSA (singular spectrum analysis). Multiplicative models containing a trend in the form of a linear or autoregression model with the calculation of the seasonality index, as well as additive models with a trend in the form of a linear or autoregression model with a seasonal component in the form of a Fourier series or sum of sines, were compared. In the Holt–Winters model, fminsearch, a function of the Matlab software package, was used to determine the tuning parameters. In the multiplicative SARIMA model, the orders of autoregression and moving average were fitted according to the autocorrelation and partial autocorrelation function. The nonparametric SSA model was used for comparison with the listed parametric models. An opportunity has been obtained to make reasonable forecasts of the production and supply of heat energy It is shown that the best results (average relative error 6.52%) were obtained using the SARIMA multiplicative model. [ABSTRACT FROM AUTHOR]

Problems associated with the development of heat-supply systems for large- and medium-size cities in Russia are analyzed. To this end, the approved heat-supply schemes of almost forty cities are reviewed and briefly analyzed taking into account their key territorial features. The main features of heat-supply systems for cities are analyzed, including the state of heat networks, excess capacities of sources, parameters of combined heat and power plants operating in the forced generation mode, and also the possibilities of using secondary and renewable energy sources for heat generation. The specific indicators characterizing heat consumption are calculated with taking into account, among other factors, the heating season degree days. The dependences of specific fuel consumption and energy generation efficiency on the climatic parameters, population density, and other factors are considered. For estimating the potential efficiency improvement reserves, consolidated data on the total installed capacity and heat-supply modes in cities are given. The aim of the study was to reveal the key problems and main trends associated with the development of heat-supply systems for cities. Large- and medium-size cities of Russia were distributed into a few typological groups, and their analysis has shown similarity of the problems occurring in them along with possible sets of typical measures and methods for solving them. The effectiveness of heat-supply systems as a whole for some cities depending on the population density and number and in different climatic zones is estimated. It is found that the obtained indicators characterizing the resulting efficiency of heat-supply systems are not directly linked with the fraction of industrial load, population density, and climate. In elaborating the heat-supply schemes, it is proposed to use the energy and environmental effectiveness indicators for revealing the key reserves for sustainable development of the most important life-support infrastructures of cities in Russia's different climatic zones. [ABSTRACT FROM AUTHOR]

The article presents own four stage methodology for calculating stresses and elongations in Pre-insulated Pipe Systems (PiPS) for heat transmission networks, taking into account the changes in diameter in the considered section. The application of this methodology leads to systematization and automation of data processing related to PiPS, which reduces the effort and costs required for the design and ensures compliance with the conditions for maximum load. The developed approach can be used to build an Information System based on Software Design Patterns. [ABSTRACT FROM AUTHOR]

The integration of thermal energy storage systems enables improvements in efficiency and flexibility for numerous applications in power plants and industrial processes. By transferring such technologies to the transport sector, existing potentials can be used for thermal management concepts and new ways of providing heat can be developed. For this purpose, technology developments for solid media high-temperature thermal energy storage systems are taking place for battery-electric vehicles as part of the DLR Next Generation Car (NGC) project. The idea of such concepts is to generate heat electrically, to store it efficiently and to discharge it through a bypass concept at a defined temperature level. The decisive criterion when using such solutions are high systemic storage densities which can be achieved by storing heat at a high temperature level. However, when storing high temperature heat increasing dimensions for thermal insulation are required, leading to limitations in the achievable systemic storage density. To overcome such limitations, an alternative thermal insulation concept is presented. Up to now, conventional thermal insulations are based on sheathing the storage containment with efficient thermal insulation materials, whereby the thickness results from safety restrictions with regard to the permitted maximum surface temperature. In contrast, the alternative concept enables through the integration of the external bypass into the thermal insulation systemic advantages during the charging and discharging period. During discharging, previously unused amounts of heat or heat losses within the thermal insulation can be integrated into the bypass path and the insulation thickness can be reduced during loading through active cooling. Using detailed models for both the reference and the alternative thermal insulation concept, systematic simulation studies were conducted on the relevant influencing variables and on the basis of defined specifications. The results confirm that the alternative thermal insulation concept achieves significant improvements in systemic storage densities compared to previous solutions and high potentials to overcome existing limitations. [ABSTRACT FROM AUTHOR]

Stability of a subsonic boundary layer with heat supply into its narrow band is studied. The maximum length of the stable boundary layer in the case of heat supply is found to be approximately three times smaller as compared to the case of a thermally insulated wall without heat supply. The frequency range of disturbances and their growth rates are approximately doubled. In contrast to the case without heat supply, three-dimensional disturbances are the most rapidly growing disturbances. In the case of a heated wall, the growth rate of disturbances decreases after heat supply into the boundary layer, which may lead to an increase in the length of the laminar region of the boundary layer. [ABSTRACT FROM AUTHOR]

The result of improving the pasteurizer is a 6-fold decrease in the specific metal consumption by the device, in comparison with the basic design (26 kg/m2 versus 160 kg/m2). The duration of heating and pasteurization of drinking milk at a temperature of 73...77 °C while aging over 15...20 s is 27.5 s, which is 1.8 times less. A reduction in the heat consumption for heating the apparatus is achieved, which is 1,372.8 kJ (CPiPPU - Continuous "pipe in pipe" pasteurization unit), in comparison to the consumption by the basic pasteurizer, 8,448 kJ. The uniformity of flow heating was established when its speed changes from 0.03 to 0.40 m/s for various heat supply techniques; under the condition =0.4 m/s, a temperature drop is ensured: at internal heating - 1.4 °C; in the basic design with external heating by a hot heat carrier - 2.7 °C; and in the proposed CPiPPU with double-sided heating - 0.5 °C. The comparison of heat supply techniques confirms the heat exchange efficiency of raw material processing by CPiPPU while ensuring a minimum temperature drop. The improved continuous pipe-inpipe pasteurization unit based on the double-sided heating by a flexible film resistive electric heater of the radiating type (FFREHRT) is resource-efficient and can be used to heat food raw materials in the temperature range 15...110 °C [ABSTRACT FROM AUTHOR]

Copyright of Revista Espacios is the property of Talleres de Impresos Oma and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In Russia, the legislative support for the construction and operation of heating systems is permanently developing and improving. The Federal law "On heat supply" adopted in 2010 is the basic and most important document that regulates the work of heating systems. Moreover, the country has more than 10 additional documents that regulate this industry, and a great number of documents that establish rules for building and operating energy systems. The paper presents the main documents that regulate the heat supply industry in the Russian Federation, and a brief description of the main stages of heating system life cycle and problems solved in each of them. Despite the national policy of energy conservation and energy efficiency enhancement, there are still problems related to heat supply management due to large extension, complexity and a variety of types and structures of the systems. The main cause of the poor heat supply efficiency in Russia is explained by a considerable change in the structure of heat loads that has occurred of late years, a decrease in the loading of the main generating equipment and heat networks, which amid other things is fostered by an increasing wear of the systems. Upgrading of generating capacities and heat networks is considered in the framework of long-term investment projects for their modernization and expansion. The obtained solutions are reflected in the Schemes of urban heat supply. This paper proposes solutions aimed at enhancing the effectiveness of decisions made in the field of heat supply. It formulates the proposals on organization and regulation of the activities of all the participants in heat supply in the stage of long-term planning of heating system expansion, because well-founded and rational planning of construction and expansion of the systems is a basis for their efficient operation. [ABSTRACT FROM AUTHOR]

For estimating the reliability of existing and newly developed circuit diagrams of heat networks, a special procedure is applied. By applying this procedure, which uses such input data as the length and operation time of pipeline segments, it is possible to determine the availability factors and probabilities of failure-free operation for a heat network. The aims of this study are to reveal and consider additional factors in determining the failure rate of heat network pipelines and to develop a new procedure for calculating indicators characterizing the reliability of heat supply to consumers. The failure rate of heat network elements depends, apart from the time they have been in operation, on the pipeline wall residual thickness, corrosion activity of soil, pipeline material, failure of a pipeline batch, other (previous) bursts in the considered segment, conduit flooding (flooding traces), and intersections with other utility lines. Additional factors significantly influencing the heat supply reliability, which, however, have not been included in the currently used procedure, are revealed, and an algorithm for calculating the heat network reliability is developed. The influence of the additional factors on the reliability of heat network operation is evaluated proceeding from the field data presented by regional heat supply companies. The influence of additional factors is taken into account in elaborating the new procedure and algorithm for calculating the heat supply's reliability indicators. The results from numerical and experimental investigations confirmed the possibility of using the obtained functional dependencies for elaborating a procedure of calculating heat network's reliability taking external factors into account. [ABSTRACT FROM AUTHOR]

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The aim of the research was to explore the proposed solar installation, which consisting of a solar wall, storage tank, radiation sources and measuring equipment. The solar installation was tested in a circulating mode, which is an important point in energy conservation. Planning the installation of the collector heating system is still at the stage of building the house. Therefore, it remains relevant to replace the traditional boiler on the solar wall in quality of the solar collector, which will be used to heat water in the system and/or the pool completely free of charge. Proposed construction of the solar wall is effective for the solar heat supply system, at the same time the results of research confirm not only the efficiency of the system, but also allow for the design stage to take into account the practical efficiency of the system. Solar wall in circulation mode has a sufficiently effective coefficient for combined hot water supply or preheating of the heating medium of the heating system. The main theses of this work also would like to mark the affordability for the consumer, since the following design does not require a separate installation, and has the ability to mount in the existing wall. [ABSTRACT FROM AUTHOR]

The current state of exploitation of low-potential thermal waters of the East Ciscaucasia Artesian Basin has been evaluated. Low-potential waters, which are the only source of water supply for a considerable number of consumers in the North Caucasus, are being exploited in an extremely inefficient way with at most 20% of the allocated resources being utilized to the fullest extent. Abusive exploitation of the wells resulted in the bogging of large areas around them, depletion of water resources, and deterioration of the latter as a consequence of backflow of low-quality water from adjacent horizons into those being exploited. The quality of the water has drastically deteriorated; in most wells, contaminants, such as arsenic and various organic compounds, have been detected in quantities that considerably exceed the maximum permissible concentrations set for potable water. These thermal waters are not being used for generation of heat and power since their temperature is too low for heat and hot-water supply purpose. However, the resources of low-potential waters are sufficient to solve the problems of heat and hot-water supply and to provide a considerable number of consumers in the region with potable and process water provided that these resources are exploited in a sensible way using new complex technologies. Complex engineering systems comprise a system of heat pump plants in which the low-potential heat of thermal waters is utilized and a chemical treatment plant in which the cooled water is purified from contaminants, thus raising its quality to the potable water standard. The designs and technological parameters of the chemical treatment plants differ depending on the composition and amount of contaminants. The complex systems allow utilization of the product of thermal artesian wells to the fullest possible extent and large-scale introduction of such systems will facilitate the solution of environmental and economic problems in the region and improve sanitary, hygienic, social, and living conditions of people. [ABSTRACT FROM AUTHOR]

Copyright of Renewable Energy / Vidnovluvana Energetyka is the property of Institute of Renewable Energy of NAS of Ukraine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)