The work is devoted to research on the improvement of thermal energy production technologies in gas-consuming heating boiler installations while improving their environmental performance and increasing the operation reliability. The work purpose is to study the heat and humidity modes of the air-supply ducts of boiler plants with exhaust gases recirculation systems into the blown air. The main objectives of the study are: to determine the thermal parameters of a heating boiler with a 2 MW heating capacity with a exhaust gases recirculation system mixed with blown air into its furnace space under conditions of using heat recovery technologies and without them; determination and analysis the heat and humidity parameters of this mixture in different operating modes of boiler plants. Known thermal calculation methods of boiler plants and data from our own experimental studies of heat transfer during deep cooling of boiler plant exhaust gases were used. The thermal calculation results of the heating boiler with a system for exhaust gas recirculation into its furnace space mixed with blown air are presented. The regularities of changes in the adiabatic combustion temperature and heat-humidity characteristics of the above mixture depending on the boiler heat load in different its operation modes during the heating period and the share of flue gas recirculation from 10 to 20 % were established. The research results show that the introduction of recirculation gases leads to a decrease by 150 – 250 °С of the adiabatic combustion temperature tad due to the need to consume fuel heat for heating the introduced ballast and the greater of the recirculation share s the lower the level of the indicated temperature. The research results also showed that gas recirculation causes insignificant (in the range of 0.5 – 4.7 °С) changes in the temperature of the boiler exhaust gases. Based on the data obtained, the change regularities in the heat-humidity characteristics (temperature and dew point) of the mixture of recirculated gases and air in different boiler operating modes during the heating period and under the studied recirculation shares were established. It is shown that recirculation causes condensate formation on the surfaces of air ducts in all operating modes of boiler and in some modes their icing is possible. To prevent these negative phenomena, it is necessary to apply measures to increase the temperature of the gas-air mixture by a value not less than Δtsum = 15 – 35 °С.
{"title":"OPERATION FEATURES OF ENVIRONMENTALLY EFFICIENT BOILER PLANTS OF MUNICIPAL THERMAL POWER ENGINEERING","authors":"Марії Капніст","doi":"10.31472/ttpe.2.2023.6","DOIUrl":"https://doi.org/10.31472/ttpe.2.2023.6","url":null,"abstract":"The work is devoted to research on the improvement of thermal energy production technologies in gas-consuming heating boiler installations while improving their environmental performance and increasing the operation reliability. The work purpose is to study the heat and humidity modes of the air-supply ducts of boiler plants with exhaust gases recirculation systems into the blown air. The main objectives of the study are: to determine the thermal parameters of a heating boiler with a 2 MW heating capacity with a exhaust gases recirculation system mixed with blown air into its furnace space under conditions of using heat recovery technologies and without them; determination and analysis the heat and humidity parameters of this mixture in different operating modes of boiler plants. Known thermal calculation methods of boiler plants and data from our own experimental studies of heat transfer during deep cooling of boiler plant exhaust gases were used. The thermal calculation results of the heating boiler with a system for exhaust gas recirculation into its furnace space mixed with blown air are presented. The regularities of changes in the adiabatic combustion temperature and heat-humidity characteristics of the above mixture depending on the boiler heat load in different its operation modes during the heating period and the share of flue gas recirculation from 10 to 20 % were established. The research results show that the introduction of recirculation gases leads to a decrease by 150 – 250 °С of the adiabatic combustion temperature tad due to the need to consume fuel heat for heating the introduced ballast and the greater of the recirculation share s the lower the level of the indicated temperature. The research results also showed that gas recirculation causes insignificant (in the range of 0.5 – 4.7 °С) changes in the temperature of the boiler exhaust gases. Based on the data obtained, the change regularities in the heat-humidity characteristics (temperature and dew point) of the mixture of recirculated gases and air in different boiler operating modes during the heating period and under the studied recirculation shares were established. It is shown that recirculation causes condensate formation on the surfaces of air ducts in all operating modes of boiler and in some modes their icing is possible. To prevent these negative phenomena, it is necessary to apply measures to increase the temperature of the gas-air mixture by a value not less than Δtsum = 15 – 35 °С.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"3 2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78067057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Geletukha, T. Zheliezna, P. Kucheruk, S. Drahniev
The purpose of the work is a comprehensive assessment of Ukraine’s bioenergy potential. The task of the work is to develop recommendations for the practical implementation of promising directions for the potential utilisation. The research methods include calculations, study and analysis of literature, statistics and other data. The availability of considerable biomass potential for the production of various types of biofuel and energy is one of the main prerequisites for the successful development of bioenergy in Ukraine. Results of the assessment based on 2021 data show that the potential of biomass for energy in the country amounts to nearly 26 Mtoe/year. A comprehensive assessment of the potential was carried out for such components as solid biomass, biofuelі and biogas. Sources of solid biomass are various agricultural residues, various types of wood biomass and energy crops (provided they are grown on unused agricultural land). Solid biomass in the amount of more than 16 Mtoe/year is the largest component of the country's biomass energy potential accounting for 62% of the total. Expert assessments indicate the possibility of increasing this potential to about 44 Mtoe/year in the period until 2050. A scenario for the long-term use of the biomass potential for energy and biofuel production has been developed taking into account sustainability issues. To implement this scenario, it is necessary to overcome a number of barriers existing in the bioenergy sector, primarily the main ones. It also seems necessary to temporarily liberalize for Ukraine the strict sustainability criteria established by the EU RED II. This mitigation should include postponing the requirement to reduce greenhouse gas emissions (65% for biofuels and biogas for transport produced in installations that started operation from 01.01.2021); establishing a special limit for Ukraine until 2030 on the use of energy from first-generation biofuels in transport (up to 7%); expanding for Ukraine the list of feedstock for the production of advanced biofuels, including regulation of possibility to obtain raw material for biofuel production on polluted, unused, low-productivity and degraded lands.
{"title":"ANALYSIS OF PROSPECTIVE DIRECTIONS FOR USING UKRAINE’S BIOMASS POTENTIAL FOR ENERGY","authors":"G. Geletukha, T. Zheliezna, P. Kucheruk, S. Drahniev","doi":"10.31472/ttpe.2.2023.9","DOIUrl":"https://doi.org/10.31472/ttpe.2.2023.9","url":null,"abstract":"The purpose of the work is a comprehensive assessment of Ukraine’s bioenergy potential. The task of the work is to develop recommendations for the practical implementation of promising directions for the potential utilisation. The research methods include calculations, study and analysis of literature, statistics and other data. The availability of considerable biomass potential for the production of various types of biofuel and energy is one of the main prerequisites for the successful development of bioenergy in Ukraine. Results of the assessment based on 2021 data show that the potential of biomass for energy in the country amounts to nearly 26 Mtoe/year. A comprehensive assessment of the potential was carried out for such components as solid biomass, biofuelі and biogas. Sources of solid biomass are various agricultural residues, various types of wood biomass and energy crops (provided they are grown on unused agricultural land). Solid biomass in the amount of more than 16 Mtoe/year is the largest component of the country's biomass energy potential accounting for 62% of the total. Expert assessments indicate the possibility of increasing this potential to about 44 Mtoe/year in the period until 2050. A scenario for the long-term use of the biomass potential for energy and biofuel production has been developed taking into account sustainability issues. To implement this scenario, it is necessary to overcome a number of barriers existing in the bioenergy sector, primarily the main ones. It also seems necessary to temporarily liberalize for Ukraine the strict sustainability criteria established by the EU RED II. This mitigation should include postponing the requirement to reduce greenhouse gas emissions (65% for biofuels and biogas for transport produced in installations that started operation from 01.01.2021); establishing a special limit for Ukraine until 2030 on the use of energy from first-generation biofuels in transport (up to 7%); expanding for Ukraine the list of feedstock for the production of advanced biofuels, including regulation of possibility to obtain raw material for biofuel production on polluted, unused, low-productivity and degraded lands.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"66 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87751976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
One of the main problems of the modern world is the search for economy of energy resources that could compete with natural gas. High-temperature furnaces are one of the biggest consumers of fuel. The heat-technology installation (furnace unit) is a set of working space within which a high-temperature process is carried out, and the equipment that ensures its implementation. The upper part of the reactor enclosure (working space) is called the vault. The vault is an element that determines the stability of the unit in general and affects the technical and economic indicators of production. On furnaces with intensive blowing of the bath with oxygen, the stability of the vault is about 300 melts. In the course of the technological process, the furnace vault is affected by the following factors: uneven heating of the inner surface of the vault along the length and width due to the uneven temperature field of the torch when heating the unit; temperature fluctuations depending on technological periods; a change in the chemical and phase composition of the refractory vault material as a result of the influence of slag and metal splashes, smelting dust and the gas atmosphere of the working space of the furnace. The intensification of thermal and technological regimes contributes to strengthening and accelerating the action of the above-mentioned processes. Therefore, special attention should be paid to the issue of high-quality heating of the vault of the unit. The article presents the results of studies of factors affecting the stability of the vault of high-temperature aggregates. On the basis of calculations based on the heat balance equations of the high-temperature unit, as well as recommendations for heating refractory products. In this article has been developed a new rational heating mode. The new thermal mode of heating the vault of the furnace will ensure a uniform temperature gradient over the entire surface of the vault, as well as the space of the furnace: with exposure to 300°С and 800°С in the zones of increased linear expansion of directly bonded high-temperature products. And also increase the productivity of the unit due to faster entry into the working mode. The fuel reduction for the heating process is estimated about 10.7%.
{"title":"IMPROVEMENT OF THERMAL MODES OF WARMING UP HIGH-TEMPERATURE UNITS","authors":"O.A. Petryk, I. Nazarenko","doi":"10.31472/ttpe.2.2023.7","DOIUrl":"https://doi.org/10.31472/ttpe.2.2023.7","url":null,"abstract":"One of the main problems of the modern world is the search for economy of energy resources that could compete with natural gas. High-temperature furnaces are one of the biggest consumers of fuel. The heat-technology installation (furnace unit) is a set of working space within which a high-temperature process is carried out, and the equipment that ensures its implementation. \u0000The upper part of the reactor enclosure (working space) is called the vault. The vault is an element that determines the stability of the unit in general and affects the technical and economic indicators of production. \u0000On furnaces with intensive blowing of the bath with oxygen, the stability of the vault is about 300 melts. In the course of the technological process, the furnace vault is affected by the following factors: \u0000 \u0000uneven heating of the inner surface of the vault along the length and width due to the uneven temperature field of the torch when heating the unit; \u0000temperature fluctuations depending on technological periods; \u0000a change in the chemical and phase composition of the refractory vault material as a result of the influence of slag and metal splashes, smelting dust and the gas atmosphere of the working space of the furnace. The intensification of thermal and technological regimes contributes to strengthening and accelerating the action of the above-mentioned processes. Therefore, special attention should be paid to the issue of high-quality heating of the vault of the unit. \u0000 \u0000The article presents the results of studies of factors affecting the stability of the vault of high-temperature aggregates. \u0000On the basis of calculations based on the heat balance equations of the high-temperature unit, as well as recommendations for heating refractory products. In this article has been developed a new rational heating mode. \u0000The new thermal mode of heating the vault of the furnace will ensure a uniform temperature gradient over the entire surface of the vault, as well as the space of the furnace: with exposure to 300°С and 800°С in the zones of increased linear expansion of directly bonded high-temperature products. And also increase the productivity of the unit due to faster entry into the working mode. The fuel reduction for the heating process is estimated about 10.7%.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76574392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Skalozubov, O. Dorozh, V. Kondratyk, S. Kosenko, V.I. Konshin
The consequences of thermoacoustic instability of the coolant in the active zone of nuclear reactors can be high-amplitude, high-frequency dynamic loads on the internal structures and a violation of the tightness of the TVEL shells. However, until now, there are no reactor control/diagnostic systems and operational instructions for managing accidents in conditions of thermoacoustic instability of the coolant in the reactor core. The main reason for this situation is the lack of substantiated methods for modeling the criteria and conditions for the occurrence of thermoacoustic instability in the active zone. The purpose of the work is the development of a criterion method for modeling the conditions of thermoacoustic instability of the coolant in the active zone of the reactor to substantiate the appropriate reactor control systems and symptom-oriented emergency instructions. An original method of determining the criteria and conditions of thermoacoustic instability of the coolant in the active zone depending on the determining parameters of the thermodynamic state of the reactor plant has been developed.. Based on the thermodynamic approach, which takes into account the level of completion of interphase heat and mass transfer processes in acoustic pressure waves, the criteria and area of thermoacoustic instability of the coolant in the reactor core are determined. The established area of thermoacoustic instability of the coolant in the reactor core was verified on the basis of known experimental data obtained at the experimental installation, which meets the criteria of thermodynamic similarity to the core of the VVER-1000 core. Based on the developed criterion method, the main provisions and requirements for the relevant reactor control/diagnostic systems and symptom-oriented instructions for managing accidents in conditions of thermoacoustic instability of the coolant in the active zone of the reactors are defined.
{"title":"APPROACHES TO MODELING CONDITIONS OF THERMOACOUSTIC INSTABILITY IN NON-EQUILIBRIUM TWO-PHASE COOLANT OF NUCLEAR REACTORS","authors":"V. Skalozubov, O. Dorozh, V. Kondratyk, S. Kosenko, V.I. Konshin","doi":"10.31472/ttpe.2.2023.11","DOIUrl":"https://doi.org/10.31472/ttpe.2.2023.11","url":null,"abstract":"The consequences of thermoacoustic instability of the coolant in the active zone of nuclear reactors can be high-amplitude, high-frequency dynamic loads on the internal structures and a violation of the tightness of the TVEL shells. However, until now, there are no reactor control/diagnostic systems and operational instructions for managing accidents in conditions of thermoacoustic instability of the coolant in the reactor core. The main reason for this situation is the lack of substantiated methods for modeling the criteria and conditions for the occurrence of thermoacoustic instability in the active zone. The purpose of the work is the development of a criterion method for modeling the conditions of thermoacoustic instability of the coolant in the active zone of the reactor to substantiate the appropriate reactor control systems and symptom-oriented emergency instructions. An original method of determining the criteria and conditions of thermoacoustic instability of the coolant in the active zone depending on the determining parameters of the thermodynamic state of the reactor plant has been developed.. Based on the thermodynamic approach, which takes into account the level of completion of interphase heat and mass transfer processes in acoustic pressure waves, the criteria and area of thermoacoustic instability of the coolant in the reactor core are determined. The established area of thermoacoustic instability of the coolant in the reactor core was verified on the basis of known experimental data obtained at the experimental installation, which meets the criteria of thermodynamic similarity to the core of the VVER-1000 core. Based on the developed criterion method, the main provisions and requirements for the relevant reactor control/diagnostic systems and symptom-oriented instructions for managing accidents in conditions of thermoacoustic instability of the coolant in the active zone of the reactors are defined.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81481326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
докт. техн. наук, Целень Б.Я канд. техн. наук, канд. техн. наук Резакова Т.А, канд. техн. наук
Thousands of steam and water boilers of medium and low parameters operate in the country's industry, municipal energy, and agriculture. Their reliable work is largely determined by maintaining a rational water-chemical regime. Dissolved impurities that affect the operation of boiler equipment primarily include hardness salts. When using hard water, scale is formed on the surfaces, heat transfer deteriorates, and pipes are overheated from the heating side, which can lead to their destruction. The purpose of the work is to improve the quality of softened water, reduce the consumption of reagents, and accelerate the softening process due to the use of heat and mass exchange equipment. In the work, water desalination was carried out by the method of discrete-pulse energy input in a rotor-pulsation apparatus. Ammonia was used as a reagent for removing hardness salts. The water-ammonia mixture is processed in the rotor-pulsation apparatus at a flow pulsation frequency of 3-5 kHz and a pressure drop amplitude of 360-400 kPa until the temperature rises to 40ºС. The increase in temperature occurs due to the transition of mechanical energy into thermal energy. It was determined that the degree of softening of water is 99% at a mass concentration of ammonia of 0.022%, and the amplitude of the pressure drop is 400 kPa. As the amplitude of the pressure drop decreases to 380 and 360 kPa, the degree of water softening decreases to 90 and 95%, respectively. It is also determined that water desalination using the rotor-pulsation apparatus should be carried out in the mode of recirculation of ammonia solution with a concentration of 0.022%, with a flow pulsation frequency of 4 kHz and a pressure drop amplitude of 400 kPa. As a result of the work, the optimal technological parameters of water treatment were determined and the efficiency of its purification using the proposed equipment was proved in comparison with the conventional one.
{"title":"METHOD OF REDUCING WATER HARDNESS SALTS AND HEAT AND MASS EXCHANGE EQUIPMENT FOR ITS IMPLEMENTATION","authors":"докт. техн. наук, Целень Б.Я канд. техн. наук, канд. техн. наук Резакова Т.А, канд. техн. наук","doi":"10.31472/ttpe.2.2023.10","DOIUrl":"https://doi.org/10.31472/ttpe.2.2023.10","url":null,"abstract":"Thousands of steam and water boilers of medium and low parameters operate in the country's industry, municipal energy, and agriculture. Their reliable work is largely determined by maintaining a rational water-chemical regime. Dissolved impurities that affect the operation of boiler equipment primarily include hardness salts. When using hard water, scale is formed on the surfaces, heat transfer deteriorates, and pipes are overheated from the heating side, which can lead to their destruction. \u0000The purpose of the work is to improve the quality of softened water, reduce the consumption of reagents, and accelerate the softening process due to the use of heat and mass exchange equipment. \u0000In the work, water desalination was carried out by the method of discrete-pulse energy input in a rotor-pulsation apparatus. Ammonia was used as a reagent for removing hardness salts. The water-ammonia mixture is processed in the rotor-pulsation apparatus at a flow pulsation frequency of 3-5 kHz and a pressure drop amplitude of 360-400 kPa until the temperature rises to 40ºС. The increase in temperature occurs due to the transition of mechanical energy into thermal energy. \u0000It was determined that the degree of softening of water is 99% at a mass concentration of ammonia of 0.022%, and the amplitude of the pressure drop is 400 kPa. As the amplitude of the pressure drop decreases to 380 and 360 kPa, the degree of water softening decreases to 90 and 95%, respectively. It is also determined that water desalination using the rotor-pulsation apparatus should be carried out in the mode of recirculation of ammonia solution with a concentration of 0.022%, with a flow pulsation frequency of 4 kHz and a pressure drop amplitude of 400 kPa. As a result of the work, the optimal technological parameters of water treatment were determined and the efficiency of its purification using the proposed equipment was proved in comparison with the conventional one.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77758975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Удк, Плин Мастила, У Вузькій, КЛИНОПОДІбНІЙ Щілині, З Рухомою Стінкою
The article presents the results of a study of the lubricant flow in a narrow wedge-shaped slot with a movable wall. A solution to the problem with slip boundary conditions on the channel walls is obtained. The effect of slippage on the change in hydrostatic lift and hydraulic resistance in the slotted channel is shown. It was determined in the work that with an increase in the slip intensity (an increase in the value of the Knudsen number), the pressure variation weakens. This is due to the weakening of the interaction of the flow with the wall. As a result, the hydraulic resistance is reduced. The dependence of the relative hydrostatic lifting force on the Knudsen number and the opening angle of the channel is obtained. It is determined that with an increase in the Knudsen number, the magnitude of the hydrostatic lifting force decreases, since the influence of the flow on the wall weakens. The influence of slippage weakens with an increase in the opening angle of the channel.
{"title":"THE FLOW OF LUBRICANT IN A NARROW WEDGE-SHAPED SLOT WITH A MOVABLE WALL IS CONSIDERED","authors":"Удк, Плин Мастила, У Вузькій, КЛИНОПОДІбНІЙ Щілині, З Рухомою Стінкою","doi":"10.31472/ttpe.2.2023.2","DOIUrl":"https://doi.org/10.31472/ttpe.2.2023.2","url":null,"abstract":"The article presents the results of a study of the lubricant flow in a narrow wedge-shaped slot with a movable wall. A solution to the problem with slip boundary conditions on the channel walls is obtained. The effect of slippage on the change in hydrostatic lift and hydraulic resistance in the slotted channel is shown. \u0000 It was determined in the work that with an increase in the slip intensity (an increase in the value of the Knudsen number), the pressure variation weakens. This is due to the weakening of the interaction of the flow with the wall. As a result, the hydraulic resistance is reduced. \u0000The dependence of the relative hydrostatic lifting force on the Knudsen number and the opening angle of the channel is obtained. It is determined that with an increase in the Knudsen number, the magnitude of the hydrostatic lifting force decreases, since the influence of the flow on the wall weakens. The influence of slippage weakens with an increase in the opening angle of the channel.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75787412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Obodovych, V. Sydorenko, Y. Bulii, O. E. Stepanova
An analysis of TPP wastewater, as well as technologies and equipment for their treatment, for choosing a rational mode and determining the maximum permissible concentrations of harmful substances characteristic of the energy industry before discharge into reservoirs was carried out. The compositions of the listed effluents are different and are determined by the type of thermal power plants (TPP) and the main equipment, its capacity, type of fuel, composition of the source water, method of water treatment, etc. For example, water after cooling turbine condensers and air coolers usually carries so-called thermal pollution, since its temperature is 8...10 ºС higher than the temperature of water in the water source. In some cases, cooling water can introduce foreign substances into natural reservoirs. In order to reduce the level of soil and groundwater pollution, local wastewater treatment facilities were constructed at thermal power stations. The second method is the collection of waste water in specially created containers with subsequent purification using sedimentation tanks and filters, which have anthracite or activated carbon as a filter material. TPP waste water is diverse and the chemical composition of each of the effluents is different. Wastewater treatment technology is complex and multi-stage and requires a large amount of various equipment. The ITTF of the National Academy of Sciences has developed a multi-purpose rotor-type aeration and oxidation plant (AORT), which works according to the method of discrete-pulse energy input (DPEI). This installation makes it possible to speed up the rate of heat and mass exchange of chemical reactions in water and water systems by 25-30 %. It makes it possible to reduce the duration of cleaning processes, reduce energy consumption by 2-3 times and consumption of reagents by 20-25 %. The AORT installation is used to clean sewage from iron, manganese, hydrogen sulfide, carbon dioxide, sulfates, and nitrates.
{"title":"WASTEWATER TREATMENT OF THERMAL POWER PLANTS (TPP)","authors":"O. Obodovych, V. Sydorenko, Y. Bulii, O. E. Stepanova","doi":"10.31472/ttpe.2.2023.8","DOIUrl":"https://doi.org/10.31472/ttpe.2.2023.8","url":null,"abstract":"An analysis of TPP wastewater, as well as technologies and equipment for their treatment, for choosing a rational mode and determining the maximum permissible concentrations of harmful substances characteristic of the energy industry before discharge into reservoirs was carried out. The compositions of the listed effluents are different and are determined by the type of thermal power plants (TPP) and the main equipment, its capacity, type of fuel, composition of the source water, method of water treatment, etc. For example, water after cooling turbine condensers and air coolers usually carries so-called thermal pollution, since its temperature is 8...10 ºС higher than the temperature of water in the water source. In some cases, cooling water can introduce foreign substances into natural reservoirs. In order to reduce the level of soil and groundwater pollution, local wastewater treatment facilities were constructed at thermal power stations. The second method is the collection of waste water in specially created containers with subsequent purification using sedimentation tanks and filters, which have anthracite or activated carbon as a filter material. \u0000TPP waste water is diverse and the chemical composition of each of the effluents is different. Wastewater treatment technology is complex and multi-stage and requires a large amount of various equipment. \u0000The ITTF of the National Academy of Sciences has developed a multi-purpose rotor-type aeration and oxidation plant (AORT), which works according to the method of discrete-pulse energy input (DPEI). This installation makes it possible to speed up the rate of heat and mass exchange of chemical reactions in water and water systems by 25-30 %. It makes it possible to reduce the duration of cleaning processes, reduce energy consumption by 2-3 times and consumption of reagents by 20-25 %. The AORT installation is used to clean sewage from iron, manganese, hydrogen sulfide, carbon dioxide, sulfates, and nitrates.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90984849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yurii Sniezhkin, N.О. Dabizha, N. Dmytrenko, N. Malashchuk
The high demand for aromatic herbs in the biotechnological, cosmetic, pharmaceutical and food industries led to increased requirements for the technological processes of processing aromatic raw materials to preserve biologically active substances and essential oils. Peppermint (Mentha piperita L.) is a well-known medicinal essential oil crop that is widely distributed throughout Ukraine. It is widely used due to its beneficial properties and therapeutic effect on the human body. The purpose of the article is studies of sorption and thermodynamic properties of aromatic plants to determine technological parameters of drying and storage processes, which ensure minimum specific energy consumption and maximum preservation of essential oils. The results of study on sorption properties of peppermint leaves are presented. Adsorption moisture isotherms of peppermint leaves were determined at three different temperatures 30, 40 and 50 ºC, using the standard gravimetric static method. The net isosteric heat of adsorption was calculated from moisture isotherms, using the Clausius-Clapeyron equation. The specific heat consumption for drying peppermint leaves at temperatures of 40 and 50 ºС was obtained experimentally, using the differential microcalorimeter of evaporation. The effect of volatile substances of peppermint essential oil on the heat of vaporization was revealed. The choice of drying temperature of aromatic plants is primarily determined by the thermal sensitivity of essential oils. The study of the effect of drying temperature on the removal of volatile aromatic compounds from peppermint leaves showed that the maximum allowable temperature of the material during dehydration should not exceed the melting point of menthol at 42,5 ºС.
{"title":"SORPTION AND THERMODYNAMIC PROPERTIES OF AROMATIC PLANTS AS DRYING OBJECTS","authors":"Yurii Sniezhkin, N.О. Dabizha, N. Dmytrenko, N. Malashchuk","doi":"10.31472/ttpe.2.2023.1","DOIUrl":"https://doi.org/10.31472/ttpe.2.2023.1","url":null,"abstract":"The high demand for aromatic herbs in the biotechnological, cosmetic, pharmaceutical and food industries led to increased requirements for the technological processes of processing aromatic raw materials to preserve biologically active substances and essential oils. Peppermint (Mentha piperita L.) is a well-known medicinal essential oil crop that is widely distributed throughout Ukraine. It is widely used due to its beneficial properties and therapeutic effect on the human body. \u0000The purpose of the article is studies of sorption and thermodynamic properties of aromatic plants to determine technological parameters of drying and storage processes, which ensure minimum specific energy consumption and maximum preservation of essential oils. \u0000The results of study on sorption properties of peppermint leaves are presented. Adsorption moisture isotherms of peppermint leaves were determined at three different temperatures 30, 40 and 50 ºC, using the standard gravimetric static method. The net isosteric heat of adsorption was calculated from moisture isotherms, using the Clausius-Clapeyron equation. \u0000The specific heat consumption for drying peppermint leaves at temperatures of 40 and 50 ºС was obtained experimentally, using the differential microcalorimeter of evaporation. The effect of volatile substances of peppermint essential oil on the heat of vaporization was revealed. \u0000The choice of drying temperature of aromatic plants is primarily determined by the thermal sensitivity of essential oils. The study of the effect of drying temperature on the removal of volatile aromatic compounds from peppermint leaves showed that the maximum allowable temperature of the material during dehydration should not exceed the melting point of menthol at 42,5 ºС.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82558557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
One of the berry crops that has recently gained popularity among consumers is blueberry (Vaccinium corymbosum L.). The berry is a powerful antioxidant, and besides, it contains fructose in its composition, which automatically refers it to the products of the diabetic diet. Therefore, blueberries become an interesting colloidal capillary-porous drying object. Wax on the skin of berries performs a protective function in the process of ripening, harvesting and transportation, but is a negative factor for the implementation of technological processing by artificial dehydration. The latter causes significant energy costs for the processing process. Therefore, the aim of the work is to determine the effect of combined drying of blueberry on energy consumption. Experimental studies of the drying kinetics of blueberry were carried out on an experimental convective stand with forced recirculation of the coolant and infrared emitters, which was developed in ІEТ of NAS of Ukraine. The effect of pre-developed hygrothermal and infrared treatment of fresh blueberries on the kinetics and change in the drying speed of berries was investigated. The use of infrared radiation made it possible to reduce the total duration of the dehydration process by 1.2 times. The heat of evaporation of moisture from the samples and their heat capacity were investigated using the method created in ІEТ of NAS of Ukraine installations of synchronous thermal analysis DMKI-01, which is intended for the study of colloidal capillary-porous materials. Determination of specific heat capacity was carried out according to the standardized method of step-by-step scanning DSTU ISO 11357–4:2010 in the temperature range from 30 to 95℃. Experimental determination of heat capacity and heat of evaporation of moisture from pre-processed blueberry showed excess energy consumption for a possible phase transition of the waxy shell of the berry during drying and a decrease in the drying efficiency of the material at moisture values Wc ≤ 20%.
最近在消费者中流行的浆果作物之一是蓝莓(Vaccinium corymbosum L.)。这种浆果是一种强大的抗氧化剂，此外，它的成分中含有果糖，这自然意味着它是糖尿病饮食的产物。因此，蓝莓成为一种有趣的胶体毛细管多孔干燥对象。浆果皮上的蜡在成熟、收获和运输过程中起着保护作用，但对人工脱水工艺的实施却是一个不利因素。后者在加工过程中造成巨大的能源成本。因此，本研究的目的是确定蓝莓复合干燥对能量消耗的影响。在乌克兰NAS公司ІEТ研制的冷却剂和红外发射器强制再循环对流实验架上，对蓝莓的干燥动力学进行了实验研究。研究了新鲜蓝莓的预发育湿热和红外处理对蓝莓干燥动力学和干燥速度变化的影响。红外辐射的使用使脱水过程的总持续时间减少了1.2倍。使用乌克兰NAS同步热分析DMKI-01装置ІEТ中创建的方法研究样品中水分的蒸发热及其热容量，该装置用于研究胶体毛细管多孔材料。比热容的测定按照DSTU ISO 11357-4:2010分步扫描的标准化方法进行，温度范围为30 ~ 95℃。对预处理蓝莓的热容和水分蒸发热的实验测定表明，在干燥过程中，蓝莓蜡质壳可能发生相变所消耗的能量过多，水分Wc≤20%时材料的干燥效率下降。
{"title":"INFLUENCE OF COMBINED DRYING OF COLLOID CAPILLARY-POROUS MATERIALS ON ENERGY EXPENDITURES","authors":"Марії Капніст","doi":"10.31472/ttpe.2.2023.5","DOIUrl":"https://doi.org/10.31472/ttpe.2.2023.5","url":null,"abstract":"One of the berry crops that has recently gained popularity among consumers is blueberry (Vaccinium corymbosum L.). The berry is a powerful antioxidant, and besides, it contains fructose in its composition, which automatically refers it to the products of the diabetic diet. Therefore, blueberries become an interesting colloidal capillary-porous drying object. Wax on the skin of berries performs a protective function in the process of ripening, harvesting and transportation, but is a negative factor for the implementation of technological processing by artificial dehydration. The latter causes significant energy costs for the processing process. Therefore, the aim of the work is to determine the effect of combined drying of blueberry on energy consumption. \u0000Experimental studies of the drying kinetics of blueberry were carried out on an experimental convective stand with forced recirculation of the coolant and infrared emitters, which was developed in ІEТ of NAS of Ukraine. The effect of pre-developed hygrothermal and infrared treatment of fresh blueberries on the kinetics and change in the drying speed of berries was investigated. The use of infrared radiation made it possible to reduce the total duration of the dehydration process by 1.2 times. \u0000The heat of evaporation of moisture from the samples and their heat capacity were investigated using the method created in ІEТ of NAS of Ukraine installations of synchronous thermal analysis DMKI-01, which is intended for the study of colloidal capillary-porous materials. Determination of specific heat capacity was carried out according to the standardized method of step-by-step scanning DSTU ISO 11357–4:2010 in the temperature range from 30 to 95℃. \u0000Experimental determination of heat capacity and heat of evaporation of moisture from pre-processed blueberry showed excess energy consumption for a possible phase transition of the waxy shell of the berry during drying and a decrease in the drying efficiency of the material at moisture values Wc ≤ 20%.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"41 3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78015389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The purpose of the work is to establish the laws of isothermal flow and mixture formation of fuel and oxidizer in a new modification of microjet burners equipped with a three-row fuel jet system and oriented to operation at various values of the excess air coefficient. The proposed burners are designed to provide the ability to control the composition of the fuel mixture in the flame stabilization zone and, in general, high efficiency of fuel combustion under the conditions under consideration. As part of the work, the following tasks were to be solved: to establish the main characteristics of the flow and mixture formation in the these burners; to identify the effects of various factors on the structure of the flow and mixture formation in these burners; to determine the rational design parameters of the fuel gas supply system, which realize favorable conditions for the mixture formation of fuel and oxidizer in the flame stabilization zone of the proposed burners. Computer simulation using Fluent code was used as a research method. The main features of aerodynamics and mixture formation of fuel and oxidizer in the considered burner devices are revealed. The dependences of the characteristics of the processes under study on a number of design and operating parameters have been established. In particular, a comparative analysis of the patterns of flow and mixture formation during the operation of burner devices was performed for various values of the excess air coefficient corresponding to the supply of fuel gas to various fuel supply sections. Data have been obtained to determine the values of the geometric parameters of the fuel supply system, under which the necessary conditions for mixture formation in the flame stabilization zone are realized.1548
{"title":"AERODYNAMICS AND MIXTURE FORMATION IN BURNERS WITH A MULTI-ROW JET FUEL SUPPLY SYSTEM","authors":"Марії Капніст","doi":"10.31472/ttpe.2.2023.4","DOIUrl":"https://doi.org/10.31472/ttpe.2.2023.4","url":null,"abstract":"The purpose of the work is to establish the laws of isothermal flow and mixture formation of fuel and oxidizer in a new modification of microjet burners equipped with a three-row fuel jet system and oriented to operation at various values of the excess air coefficient. The proposed burners are designed to provide the ability to control the composition of the fuel mixture in the flame stabilization zone and, in general, high efficiency of fuel combustion under the conditions under consideration. As part of the work, the following tasks were to be solved: to establish the main characteristics of the flow and mixture formation in the these burners; to identify the effects of various factors on the structure of the flow and mixture formation in these burners; to determine the rational design parameters of the fuel gas supply system, which realize favorable conditions for the mixture formation of fuel and oxidizer in the flame stabilization zone of the proposed burners. Computer simulation using Fluent code was used as a research method. \u0000The main features of aerodynamics and mixture formation of fuel and oxidizer in the considered burner devices are revealed. The dependences of the characteristics of the processes under study on a number of design and operating parameters have been established. In particular, a comparative analysis of the patterns of flow and mixture formation during the operation of burner devices was performed for various values of the excess air coefficient corresponding to the supply of fuel gas to various fuel supply sections. Data have been obtained to determine the values of the geometric parameters of the fuel supply system, under which the necessary conditions for mixture formation in the flame stabilization zone are realized.1548","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"120 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76005386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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