Low-potential Thermal Energy Research Articles

ОБОСНОВАНИЕ ЭНЕРГОСБЕРЕГАЮЩЕЙ ФУНКЦИОНАЛЬНОЙ СХЕМЫ АККУМУЛЯЦИОННОЙ УСТАНОВКИ ДЛЯ НАГРЕВА ВОДЫ НА ФЕРМАХ КРС

Analysis of electric energy consumption on cattle farms has shown that hot water supply is one of the energy-intensive technological processes on such farms. In order to save energy resources when heating water, a functional scheme of an accumulator installation has been developed that allows heating water for watering cows and providing technological needs. The standard water temperature for drinking is 12-15 degrees Celsius, for technological needs - 55-65 degrees Celsius. (Research purpose) The research purpose is substantiating and developing a functional scheme of an energy-saving installation for heating water using solar radiation for technological needs and thermal energy of ventilation air removed from the premises for watering cows on cattle farms. (Materials and methods) Applied patent search on the websites of Rospatent and Yandex.Patents. The analysis of analytical calculation dependencies was performed to determine the main technical characteristics of water heating installations for animal watering and technological purposes. (Results and discussion) A functional scheme of the hot water supply installation was proposed, including a water heater for technological needs using solar radiation energy and a water heater for animal watering using a thermoelectric heat pump and the heat of the ventilation air removed from the farm premises. (Conclusions) Developed a functional scheme of an accumulative water heating unit for watering cows and technological needs on cattle farms. It has been shown that the proposed scheme allows using the heat of the air removed from the premises and the renewable heat of solar radiation as alternative sources to traditional methods of heating water. The possibility of using low-potential thermal energy of the removed ventilation air for hot water supply of the animal watering system using a thermoelectric heat pump and heat pipes, as well as a solar collector for heating water for the technological needs of the farm, was investigated.

A new concept for complex mining of mineral raw material resources from DTEK coal mines based on sustainable development and ESG strategy

Purpose. The research purpose is to develop a concept for complex mining of mineral resources from coal mines using the example of PJSC DTEK Pavlohradvuhillia mines with a transition to multi-product production of clean drinking water, utilization of methane, secondary coal from rock dumps and sludge reservoirs, low-potential thermal energy of mine groundwaters and associated raw materials from desalination waste. Methods. The research uses an integrated approach, which includes an analysis of existing experience and available complex coal mining technologies, laboratory studies of mine water desalination technology by the reverse osmosis method with thermal distillation of concentrated brine, and chemical analysis using ElvaX laboratory equipment. Findings. This paper presents the research results of a comprehensive analysis of mineral raw material resources related to coal mining. The technically achievable energy potential that can be produced from the secondary coal of rock dumps and sludge reservoirs has been determined, which in total is 183.3 TJ. The annual heat potential of methane gas utilization has been estimated, which in total of PJSC DTEK Pavlohradvuhillia’s mines reaches 7.1 PJ. The possibility of extracting up to 1.12 TJ/year of associated thermal energy from the water-drainage installation of mine complexes has been determined. For the conditions of the Zakhidno-Donbaska mine, the authors of the paper have developed a technological scheme for the water preparation process by the reverse osmosis with the desalination brine treatment by the method of multistage evaporation on adiabatic evaporators. Originality. For the first time, the energy flows related to coal mining technology have been comprehensively analyzed for the possibility of their joint use to cover the needs of the mine complex. The prospects for complex mining of mineral resources have been assessed based on the adaptation of the mine complex production facilities to the multi-product production of clean drinking water, utilization of methane gas, low-potential thermal energy from mine groundwaters and secondary raw materials of desalination waste. Practical implications. The proposed set of technological solutions will ensure the sustainable development and diversification of the production of PJSC DTEK Pavlohradvuhillia coal-mining enterprises, as well as the effective transformation of coal-mining cities during the period of transition from mono-product production to the creation of multi-business production complexes that comply with ESG principles. The creation of multi-product mine complexes capable of producing not only coal, but also heat and associated mineral raw material resources, should become a guarantee of stable social-economic development of coal-mining regions.

Сравнительная оценка энергетической и экономической эффективности парокомпрессионных тепловых насосов при модернизации крупного химического и нефтеперерабатывающего производства. Часть 2

The question of the expediency of increasing the energy efficiency of a large chemical and oil refining industry by using process heat carriers and raw materials as heaters of vapor compression heat pumps based on systems for recuperating heat process losses is considered. A feature of the energy system under consideration is the provision of the main circuit of the heat pump and its drive from a common source of thermal energy. The influence of the temperature parameters of the consumer of highpotential thermal energy, the source of low-potential thermal energy and the energy efficiency of the main functional elements of the energy system under consideration on the ratio of the amount of generated thermal energy supplied to the consumer to the amount of thermal energy losses used is analyzed. In addition, an assessment is made of the influence of the listed factors on the redistribution of low-potential thermal energy flows between the main circuit of the heat pump and its drive. The presented results reflect the fundamental possibility of increasing the temperature level of process heat carriers and raw materials without significant costs for additional external energy sources. The efficiency of reuse of heat losses in a closed technological cycle depends on the temperature conditions of the consumer and the source of thermal energy in the heat pump cycle, on the connection scheme of the thermal energy source and on the energy efficiency of the equipment used.

Impact of the natural temperature regime of the upper layers of Earth on efficiency of a hydrothermal heat pump system


 
 
 This article focuses on current issues of alternative geothermal heating development, by using low-potential thermal energy of upper aquifers by heat pumping technology. This type of heat supply is sustainable, does not require fossil fuel consumption and does not pollute the environment. In recent years, heat pumping technologies have become common. A lot of heating systems are implemented, using low potential energy in the air, open bodies of water or soil. Although, now, the heat of groundwater in upper aquifers is a more efficient and reliable source of energy for heat pumps. It was tested in this study. The purpose of this study is to impact assessment of the heat regime of the ground upper layers on efficiency of operation of heat pumping units, using groundwater of near-surface horizons. The factors founded, which form the natural heat mode within the studied area, also the correlation established between temperature changes in the horizon and the operation of the heat pump unit, based on the experimental heat pump unit, established by the Institute of Renewable Energy of the National Academy the Sciences of Ukraine. The article presents an experimental hydrothermal heat pump system developed and constructed at the Institute of Renewable Energy of the National Academy of Sciences of Ukraine, which consists of a heat pump and two wells through which water circulation from the underground horizon to the heat pump. The study describes the characteristics of measuring equipment installed on a hydrothermal heat pump system and described developed an interactive scheduling system based on the software product ESM (Engineering Systems Manager) using the programming language FBD (Function Block Diagram | Continuous Function Chart). This software product was used to create the visual system and archival data system that were obtained in the course of this work. The benefits of this study are that the experimental installation uses the thermal energy of groundwater of the Poltava-Kharkov aquifer as the primary energy source. The interval of the productive horizon is 32-57 m. The groundwater level in the horizon is set at about 40 m. In addition, the air temperature between the pipe space of the observation well and the groundwater temperature in the aquifer are monitored. The duration of regime observations was six months, the frequency of measurements – 5-15 seconds. The monitoring results indicate that despite the fact that the productive horizon is at a depth that significantly exceeds the usual depth of the neutral layer for the territory of Ukraine, the for- mation temperature is not stable and its amplitude is 2 oC. According to the authors, the increase in the depth of the surface of constant annual temperatures may be due to local features of the studied area, namely: increasing the absorption surface of solar radiation due to terrain, the presence of lateral heat inflow, the presence of water-saturated layers in the upper part. Consequently, based on the analysis of geological and hydrogeological conditions of the site, as well as technological processes occurring in the installation, the main factors that form the natural temperature of the upper layers of the earth are identified. As a result, the percentage of energy efficiency drop of the installation is calculated depending on the decrease in the temperature of the natural heat carrier in the aquifer. It is established that it is necessary to conduct additional research to assess the environmental impact of the use of aquifers for energy purposes and to ensure the optimal mode of operation of aquifers, which would be as close as possible to their natural regime.
 
 

ПОВЫШЕНИЕ ЭФФЕКТИВНОСТИ ПЕРВИЧНОЙ ОБРАБОТКИ МОЛОКА НА ФЕРМАХ

Technological processes of primary processing and storage of livestock products require large volumes of low-potential thermal energy. One of the effective ways to preserve the high quality of milk, reduce the energy consumption of primary processing and storage of livestock products is the use of alternative energy sources. The author has analyzed systems for primary processing and storage of milk based on the use of natural cold, vacuum and thermoelectric modules. The article shows the advantages of such systems as compared with traditional ones and gives the classification of equipment using natural cold. It is noted that when using natural cold, the cost of electricity for cooling milk is reduced to 10…12 kWh/t, and when using a hybrid vacuum-evaporation plant – up to 15…18 kWh/t. The article presents a technological scheme of a thermoelectric installation for milk cooling and pasteurization and recuperative heating of washing water on farms with milking robots. Based on the performed analysis the author makes recommendations on the use of alternative energy sources for milk pre-cooling on farms with milking robots. It is established that the use of alternative energy sources provides for environmentally safe, energy-saving and reliable primary processing and storage of livestock products in the places of its production, and contributes to a significant reduction in losses and preservation of high quality. Studies have proved the effectiveness of using combined cooling and storage systems for livestock products using natural cold in combination with thermoelectric, vacuum, and ground cooling.

Термодинамічна енергоефективність парокомпресійного теплового насоса на грунтових водах

The thermodynamic energy efficiency of a steam compression heat pump (PKTN) using natural sources of environmental heat, in particular groundwater, is considered in the article. The scheme of PKTN "water-water" for the heat supply system, temperature levels in the general system of PKTN "water-water" are presented and the example of work of the PKTN "water-water" cycle in the p-h diagram for propane (R290) is given. The results of a thermodynamic study of the energy efficiency of the use of PKTN when using groundwater as a source of low-potential thermal energy are presented. The article considers the use of pure hydrocarbons as working substances for PKTN, as well as a method for assessing energy efficiency by exergy analysis of thermodynamic energy conversion processes occurring in PKTN, the working fluid of which is the refrigerant R290. The energy efficiency of PКTN was estimated by the conversion coefficient of TH COP, it is calculated to be 4.5. The thermodynamic efficiency of PKTN in heat supply systems was considered using exergy efficiency depending on the average thermodynamic temperatures of heat carriers in the condenser and evaporator, which characterizes the perfection of energy conversion and is 44%. A thermodynamic study of the effectiveness of PKTN "water-water" for the space heating system using groundwater as a source of low-potential thermal energy. Evaluation of energy efficiency of thermodynamic processes of energy conversion occurring in PKTN "water-water" whose working fluid is a refrigerant R290 (propane) is performed by the method of exergetic analysis. It is shown that the exergetic efficiency of PKTN "water-water" depending on the average thermodynamic temperatures of evaporation and condensation is 44%.

ПОРІВНЯЛЬНИЙ АНАЛІЗ ГІДРОТЕРМАЛЬНИХ ТЕПЛОНАСОСНИХ УСТАНОВОК ЗАКРИТОГО ТА ВІДКРИТОГО ТИПУ З РІЗНИМИ ДЖЕРЕЛАМИ НИЗЬКОПОТЕНЦІЙНОЇ ЕНЕРГІЇ

The article is devoted to a new direction of using the waters of the upper aquifers and open reservoirs for heat and cold supply of residential and public buildings and structures. The theoretical analysis of technologies of construction and features of use of natural accumulators of thermal energy in aquifers is carried out. The general schemes of construction of hydrothermal power systems of closed and open type are described. The hydrothermal experimental heat pump power system developed and constructed at the Institute of Renewable Energy of the National Academy of Sciences of Ukraine consisting of a heat pump and two wells with a depth of 49.5 m and 57.5 m, through which water is pumped or pumped from the aquifer, is presented. The geomorphological, geological and hydrogeological conditions of the study site are analyzed. The peculiarities of the formation of groundwater reserves of the productive horizon are described. Further directions of hydrogeological observations have been determined. The efficiency of the hydrothermal heat pump energy system of the open type is scientifically substantiated. Research methods are described. The characteristics of the measuring equipment and the software which was used for archiving and visualization of the data received in the course of carrying out research work are resulted. The results of experimental researches are presented. A comparative analysis of the efficiency and investment attractiveness of the hydrothermal system of open and closed type, where low-potential thermal energy of water is used as a renewable primary source of thermal energy for the operation of the heat pump was carried out. It is established that the use of renewable low-potential ground energy for the operation of geothermal energy systems is widely used in environmentally safe and economically attractive energy systems. However, the use of hydropower potential in hydrothermal energy systems is not widely used, despite the high technical and economic performance. It is proved that the existing hydrothermal systems are not always adapted to the operating conditions and location of the facility. There is no method of designing open-type hydrothermal systems, methods of conducting preliminary hydrogeological studies of the area planned for the installation of these systems and methods of calculating the parameters of the storage medium. The data obtained during the study are of great scientific and applied importance in the design of hydrothermal energy heat pump systems. In addition, there are prospects for further research into the possibility and effectiveness of using the aquifer as a natural heat accumulator to stabilize the generation of energy from renewable sources, regardless of climatic conditions and time of year.

Experimental studies of energy efficiency of heat pump equipment for hot water supply and air conditioning systems in apartment buildings

Experimental studies of this article are aimed at solving the problem of reforming the housing and communal services of Russia through rational integration of non-traditional energy sources and secondary energy resources into the energy balance of buildings and structures. An important component of the work was the creation and development of industrial production of reliable competitive heat pump systems of a new generation, cogenerating heat energy and cold in an autonomous mode and providing energy savings of at least 50% due to the combined use of low-potential thermal energy of the soil, the atmospheric air and the exhaust air of ventilation systems for hot water supply and air conditioning systems of apartment buildings.

Використання теплових насосів для опалення та гарячого водопостачання будівель підприємств на прикладі установок Helioterm

Heat pump - a device for transferring thermal energy from a source of low potential thermal energy to a consumer with a higher temperature. The thermodynamic cycle of a heat pump is similar to a refrigerating machine. Depending on the principle of operation, heat pumps are divided into compression and absorption. The most commonly used compression heat pumps. In recent years, numerous publications on the use of heat pump technology in heating and hot water supply facilities of various spheres - from individual homes to residential neighborhoods have appeared in various media. The authors of the publication have many years of experience in joint scientific and technical cooperation with leading technical universities and industrial organizations in the field of development and practical use of heat pump technology. The authors analyze the possibilities of introducing heat pumps at enterprises and organizations of the State Reserve System of Ukraine. It has been shown that the amount of expenses in comparison with central heating or operation of gas and electric boilers of similar power is several times smaller. It is noted that the implementation of heat pumps is a promising direction in the use of alternative energy sources to meet the heating, ventilation and hot water supply needs of buildings. The payback period from the introduction of heat pumps at enterprises is 4-9 years, depending on the location of the object and the type of source of low-temperature heat. The article meets the requirements of the State Tax Code of Ukraine and can be recommended for publication.

Алгоритм расчета эксплуатационных характеристик паровой компрессорной холодильной установки с адсорбционным холодильным модулем

The work is focused on the development of an effective algorithm for calculating the operational characteristics of a steamcompressive chilling machine with an adsorptive chilling unit, which involves a cold box, an adsorber, an evaporator and a condenser, water being used as a refrigerant. An algorithm for calculating the operating parameters of the adsorptive chilling unit has been developed, which includes the determination of the cooling capacity of the steam compressor refrigeration unit, the heat load on the condenser, the power consumed by the compressor, the coefficient of performance of the steam compressor refrigeration unit, as well as the calculation of the mass of water, the mass of the adsorbent, the refrigerating capacity, the coefficient of performance of the adsorptive chilling unit and the coefficient of useful energy utilization of a steam compressive chilling machine with an adsorption chilling unit. The chilling capacity and the coefficient of performance of the adsorption chilling unit are estimated under the operating conditions of a typical steam compression chilling machine. The crucial factors affecting the efficiency of the adsorptive chilling unit are analyzed. It has been established that the chilling capacity, the coefficient of performance of the adsorption refrigeration module and the energy efficiency of the installation are determined by the thermal load on the condenser, and, therefore, by the mass of water that is desorbed and evaporated. The coefficient of performance of the adsorption chilling unit and the efficiency of the steam compressor chilling machine with the adsorptive chilling unit are estimated to be 0.878 and 4.64. The criteria for the selection of adsorbents for the adsorption module are analyzed. The temperature of regeneration is determined by the temperatures in the condenser, and the limit adsorption affects the mass of the adsorbent and the size of the adsorber. A comparison of the efficiency of adsorptive chi l l ing uni t based on silicoaluminophosphates and composite adsorbents «silica gel – sodium acetate» is carried out. The prospects of using composites «silica gel – СН3СООNa» are shown. The optimal composition of the composite was established, which corresponds to the minimal size of the adsorber, (80% sodium acetate and 20% silica gel). The prospects of using adsorptive conversion of thermal energy for utilization of low-potential thermal energy during the operation of steam compressive chilling machine are shown. Keywords: adsorptive conversion of heat energy, composite adsorbent, steam compressive chilling unit, adsorption, adsorptive capacity.

Ефективність циклу теплового насоса для теплопостачання

The aim of the article is to analyze the literature and scientific publications on the effectiveness of the heat pump in heat supply systems and to study the efficiency of using the steam compression cycle of a heat pump in a heat supply system. Тo conduct energy and exergy analysis of heat pump efficiency indicators, the working fluid of which is freon R134a, when using natural waters as a source of low-potential thermal energy. The article analyzes the literature sources and scientific publications on the effectiveness of the heat pump in heat supply systems. The results of research of efficiency of application of the heat pump in systems of heat supply at use of natural waters as a source of low-potential thermal energy are presented. Energy and exergy analysis of heat pump efficiency indicators, the working fluid of which is R134a freon, was performed. The energy efficiency of the heat pump cycle was determined by the conversion factor of the heat pump. The thermodynamic efficiency of the heat pump in heat supply systems was evaluated using exergetic efficiency, which is one of the main indicators of the efficiency of heat pump processes and cycles. The calculation of energy indicators of the heat pump, such as: specific heat load in the evaporator and condenser, as well as the conversion factor of the heat pump. The calculation of exergetic efficiency for ambient temperature from +10 to -10 ºC. Thus, the energy and exergy analysis of the efficiency of the heat pump, the working fluid of which is Freon R134a with a conversion factor = 4.8. This indicates that the heat pump is a reliable, highly efficient, environmentally friendly source of energy for use in heating systems. A heat pump heating system will always consume less primary energy than traditional heating systems if natural water is used as a low-temperature heat source for the heat pump. The efficiency of the steam compression cycle of the heat pump largely depends on the temperature of low-potential heat sources. The use of HV in heating systems reduces greenhouse gas emissions compared to conventional types of heat supply, which is relevant to the ecological state of the environment.

Decreasing cost of heat pump heat supply systemby changing first circuit collector

The aim of this work is to reduce the cost of the heat pump heating system by using a solar collector in the primary circuit of the heat pump. It is known that the price of material and installation of the primary circuit collector is 30% of the total cost of the heat pump heating system. The use of a solar collector in the primary circuit of a heat pump eliminates the need for drilling or underground installation of a low-potential thermal energy collector. The rejection of the classic types of collectors: horizontal collectors and vertical probes, also has a positive environmental effect on the soil. The combined use of a solar collector and a heat pump will add variability in the layout of the heat pump heating system. The article presents the results of a theoretical study of the feasibility of operating solar collectors at the latitudes of the Republic of Tatarstan. A comparative analysis of various types of heat pump and solar collector is given, based on which the main components of the combined system were selected. The work includes calculations of the required power and surface area of the absorption of the solar collector. The results of a comparative analysis of the performance of the solar collector are presented, depending on the angle of incidence of sunlight and the average level of insolation. As a result of the work, it was determined that the use of a solar collector in the primary circuit of a heat pump will be twice cheaper compared to horizontal collectors and 4 times compared to vertical probes.

ЭФФЕКТИВНАЯ «ЗЕЛЕНАЯ» ТЕХНОЛОГИЯ (SWEM) – ПРОИЗВОДСТВО ЭЛЕКТРОЭНЕРГИИ И ВОДЫ ИЗ АТМОСФЕРЫ

Thermal energy created by heating the Earth and the atmospheric air by sunlight exists in the Earth’s atmosphere in quantities many times greater than humanity’s energy needs. The authors formulated and patented the basic principles of concentration and use of this low-potential thermal energy scattered in the atmosphere. The SWEM technology proposed in the article is a way to convert this natural energy into usable electrical energy, in calculated quantities. SWEMtechnology isbasedonmechanisms that canbeobservedinsuchanaturalphenomenon as a hurricane. The SWEM module replicates the chain of transitions of aggregate states of atmospheric moisture, starting with heating the surface of the world’s oceans and evaporating water that saturates the air. The energy accumulated in the water of the sun, as a result of the chain of conversions, is converted into electricity. At the same time, as a by-product of enthalpy of cross-aggregation, fresh water is released, falling out of the air in the form of precipitation. Fresh water, like energy, is the most valuable and vital product for many people on the planet. TheSWEM water-electric module is versatile, lightweight, operationaland portable. The energy generation providing for energy or water consumption can be scaled up in the form of a synchronized battery of basic size SWEM modules or a mega-installation. SWEM modules can be placed on the ground or on the water surface, in steppe or urban landscape conditions. The technology does not require external energy sources and is absolutely green. The fundamental principles of concentration and management of the earth’s low-potential thermal energy, on which SWEM technology is based, can form the basis of a new, clean energy industry that exceeds current and future energy and water needs

ВИКОРИСТАННЯ ТЕПЛОВИХ НАСОСІВ ДЛЯ ОПАЛЕННЯ БУДІВЕЛЬ НА ПІДПРИЄМСТВАХ

Стаття присвячена висвітленню сутності та змісту такої проблеми, як використання установок, що працюють на альтернативних джерелах енергії для опалення, вентиляції та гарячого водопостачання будівель, а саме теплових насосів. Теплові насоси використовують для своєї роботи низькопотенційне тепло, яке береться з повітря, водойм та надр землі. Підприємства та організації мають різноманітні джерела низькопотенційної теплової енергії: пожежні водойми, вільні земельні ділянки на територіях.

The increasing of the energy efficiency of nuclear power plants with fast neutron reactors by utilizing waste heat using heat pumps

Today, an important task for the economy is to increase the efficiency of using primary fuel. At present, for nuclear power plants with VVER reactors, thermal efficiency is about 33%, with fast neutron reactors - more than 40%. This means that most of the heat produced is released into the atmosphere. In this paper, we consider methods to solve the problem of increasing energy efficiency by the example of NPPs with fast neutron reactors due to the utilization of low-grade waste heat. The results of practical implementation of utilization of low-potential thermal energy of thermal and nuclear power plants using heat pumps were generalized. The analysis of the utilization efficiency of waste heat from various NPP systems was performed.

Increasing the efficiency of energy generation at Krasnoyarsk CHP-2 by utilization of waste heat

The relevance of the work is due to the implementation of the Federal law “on energy saving and energy efficiency and on amendments to certain legislative acts of the Russian Federation” and is aimed at reducing environmental pollution from the production of electricity and heat at the CHP. The aim of the work is to increase the energy efficiency of electric energy generation by upgrading the coal thermal power plant, reducing environmental pollution from the enterprise by reducing the amount of fuel burned at the same capacity. Research methods are Analysis of existing technologies for utilization of low-potential thermal energy in the energy sector; Thermal, technical and economic analysis of technologies that allow converting low potential thermal energy into electrical energy; Simulation of installation parameters based on the organic Rankine cycle using the Smoweb software package; Analysis of modern manufacturers of organic Rankine cycle technology in order to select the most suitable. Results are a comparative analysis of existing technologies for utilization of low-potential heat energy was carried out and the most effective option for energy efficiency was chosen. Heat and techno-economic analysis of the application of technologies to convert low-grade thermal energy into electrical energy was performed; modeling installation using the principle of organic Rankine cycle utilizing heat energy from the boiler BKZ-420-140-PT1 was designed

Increase of energy efficiency of energy generation due to utilization of waste heat on district heating systems

The relevance of the work is due to the implementation of the Federal law “on energy saving and energy efficiency and on amendments to certain legislative acts of the Russian Federation” and is aimed at reducing the cost of production of electric and heat energy in the Northern regions of decentralized energy of Russia. The aim of the work is iimproving the energy efficiency of thermal energy production through the modernization of coal-fired boilers, the rationale for the choice of an alternative technology to convert thermal energy into electricity in the areas of decentralized energy. Creation of the installations competing with diesel power plants on development of thermal and electric energy, increase of economic efficiency of production of energy in Northern regions of Russia. Research methods is analysis of existing technologies for the production of thermal energy in the areas of decentralized energy; Thermal, technical and economic analysis of technologies that allow to convert low potential thermal energy into electrical energy; Simulation of installation parameters based on the organic Rankine cycle using the software package Smoweb software package. Results are a comparative analysis of the existing technologies for the production of thermal energy in the areas of decentralized energy and selected the most effective option for improving energy efficiency; was made thermal and technical and economic analysis of the use of technologies that allow to convert low potential thermal energy into electrical energy for the district heating systems DHS-22 of villages Podtesovo

Research of Snow-Melt Process on a Heated Platform

The article has shown the results of experimental researches of the snow-melt on a heated platform-near building heat-pump snow-melt platform. The near-building (yard) heat pump platforms for snow melt with the area up to 10-15 m2 are a basis of the new ideology of organization of the street cleaning of Moscow from snow in the winter period which supposes the creation in the megalopolis of the «distributed snow-melt system» (DSMS) using non-traditional energy sources. The results of natural experimental researches are presented for the estimation of efficiency of application in the climatic conditions of Moscow of heat pumps in the snow-melt systems. The researches were conducted on a model sample of the near-building heat-pump platform which uses the low-potential thermal energy of atmospheric air. The conducted researches have confirmed experimentally in the natural conditions the possibility and efficiency of using of atmospheric air as a source of low-potential thermal energy for evaporation of the snow-melt heat pump systems in the climatic conditions of Moscow. The results of laboratory researches of snow-melt process on a heated horizontal platform are presented. The researches have revealed a considerable dependence of efficiency of the snow-melt process on its piling mode (form-building) and the organization of the process of its piling mode (form-building) and the organization of the process of its (snow mass) heat exchange with the surface of the heated platform. In the process of researches the effect of formation of an «ice dome» under the melting snow mass called by the fact that in case of the thickness of snow loaded on the platform more than 10 cm the water formed from the melting snow while the contact with the heating surface don’t spread on it, but soaks into the snow, wets it due to capillary effect and freezes. The formation of «ice dome» leads to a sharp increase of snow-melt period and decreases the operating efficiency of the snow-melt platform as a whole.

Study of the Dependence Effectiveness of Low-potential Heat of the Ground and Atmospheric Air for Heating Buildings from Climatic parameters

The article represents the results of researches for division into districts of the territory of Russia and Europe by efficiency of using for the heat supply of buildings of low-potential thermal energy of ground and free air and their combination. While modeling of the heat regime of geothermal HPS in climatic conditions of different regions of the territory of Russia, the influence has been taken into account of the long-term extraction of geothermal heat energy on the ground heat regime as well as the influence of phase transitions of pore moisture in ground on the efficiency of operation of geothermal heat-pump heat-supply systems. While realization of the division into districts, the sinking of temperatures of ground massive was been taken into account which has been called by long-term extraction of the heat energy from the ground, and as calculation parameters of the heat energy from the ground, and as calculation parameters of ground massive temperatures, the ground temperatures were used which are waited for the 5-th year of operation of geothermal HPS.

Designing of the jet device as the element of the heat pump

The problems are examined of the effective functioning of the jet device as the main element of the heat pump allowing the recuperation of the low potential thermal energy. Regularities of the ejection, which are the basis for designing of the ejector and ejection apparatus, are described. It is shown that the effective ejection can be reached at developed regime of outflow of the liquid from the nozzle (Re>105). The common expression describing the coefficient of ejection for cases with cylindrical and flat nozzle on jet devices of various scales is presented. It is determined that flat nozzles can develop bigger values of Ke at the other equal conditions. The requirement for designing main elements of the ejector, which have to be followed for achievment of high values of coefficients of ejection, are formulated.