Pub Date : 2022-04-12DOI: 10.32347/2409-2606.2022.41.55-60
V. Vakhula
In order to preserve complex historical objects with unique architectural, engineering solutions and monumental art that are of cultural and historical value, the task of maintaining the microclimate parameters determined by museum specialists is relevant. The object of the study is St. Sophia Cathedral – a monument of architecture, history and monumental painting of national importance, which is a UNESCO World Cultural Heritage Site. The location of it in the city centre determines the influence of adverse outdoor conditions, in particular, high air pollution, and the attraction of the site – a high level of attendance and, as a result, dynamic changes in the indoor parameters of the air environment. The existing regime of heat, moisture and gases in the St. Sophia Cathedral is periodic with characteristic maxima of temperature and relative humidity values in different areas of the building when people visit it. Three series of natural studies of the air environment parameters in the Cathedral were carried out. The first series was held on 02 October 2019 at an outdoor temperature of plus 18.9 °C and a relative humidity of 47.5 % with the ventilation system turned off and on before the start of the heating season. The second series of measurements was carried out on 12-14 November 2019 at an outside air temperature of plus 8.9 °C and a relative humidity of 73 % with the ventilation turned off and the heating turned on. The third series of measurements was carried out on 08 February 2020 at an outside air temperature of minus 3.2 °C and a relative humidity of 56.2 % with ventilation off and heating on. An analysis of the results indicates the need for reconstruction and modernization of the engineering microclimate systems and heat supply of the Cathedral. Currently, the physical deterioration of heating and ventilation systems is 75-85%. They need immediate reconstruction and change of operating mode. Taking into account the performed field studies, a project for the modernization of heating, ventilation and air conditioning systems was developed.
{"title":"Energy-efficient microclimate formation in a historical religious monument building with wall paintings","authors":"V. Vakhula","doi":"10.32347/2409-2606.2022.41.55-60","DOIUrl":"https://doi.org/10.32347/2409-2606.2022.41.55-60","url":null,"abstract":"In order to preserve complex historical objects with unique architectural, engineering solutions and monumental art that are of cultural and historical value, the task of maintaining the microclimate parameters determined by museum specialists is relevant. The object of the study is St. Sophia Cathedral – a monument of architecture, history and monumental painting of national importance, which is a UNESCO World Cultural Heritage Site. The location of it in the city centre determines the influence of adverse outdoor conditions, in particular, high air pollution, and the attraction of the site – a high level of attendance and, as a result, dynamic changes in the indoor parameters of the air environment. The existing regime of heat, moisture and gases in the St. Sophia Cathedral is periodic with characteristic maxima of temperature and relative humidity values in different areas of the building when people visit it. Three series of natural studies of the air environment parameters in the Cathedral were carried out. The first series was held on 02 October 2019 at an outdoor temperature of plus 18.9 °C and a relative humidity of 47.5 % with the ventilation system turned off and on before the start of the heating season. The second series of measurements was carried out on 12-14 November 2019 at an outside air temperature of plus 8.9 °C and a relative humidity of 73 % with the ventilation turned off and the heating turned on. The third series of measurements was carried out on 08 February 2020 at an outside air temperature of minus 3.2 °C and a relative humidity of 56.2 % with ventilation off and heating on. An analysis of the results indicates the need for reconstruction and modernization of the engineering microclimate systems and heat supply of the Cathedral. Currently, the physical deterioration of heating and ventilation systems is 75-85%. They need immediate reconstruction and change of operating mode. Taking into account the performed field studies, a project for the modernization of heating, ventilation and air conditioning systems was developed.","PeriodicalId":23499,"journal":{"name":"Ventilation, Illumination and Heat Gas Supply","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87655505","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}
Pub Date : 2022-04-12DOI: 10.32347/2409-2606.2022.41.39-49
V. Popov, V. Mileikovskyi, O. O. Tryhub
The WWER-1000 reactor is operated at 13 of the 15 operating power units of Ukraine's nuclear power plants (NPPs). Ensuring long-term and safe operation of such reactors is the basis for reliable operation of all 13 Ukrainian nuclear power plants units and the guarantor of Ukraine's energy security. The determining and leading factor influencing the safety and proper residual life of the WWER-1000 reactor vessel is the radiation embrittlement of the reactor steel. The consequences of radiation embrittlement of reactor steel are negatively manifested in emergencies with cooling of the core. This process itself – radiation embrittlement – accumulates constantly and gradually. Therefore, it is important to monitor it by periodically performing ongoing rapid assessments of the brittle strength of the WWER-1000 reactor vessel (along with other factors, including cyclic damage, as discussed in a previous publication). Therefore, it is important to use the calculated express methods of periodic assessment of the brittle strength of the WWER-1000 reactor vessel with guaranteed accuracy. The effectiveness of the approach is supported by low cost of resources – engineering staff, fast and relatively simplified use of computers and software. As an example and confirmation of the applicability of the proposed approach, an expert rapid assessment of the fragile strength and residual life of the reactor vessel of Unit № 1 of the South-Ukrainian Nuclear Power Plant was performed. This takes into account the actual, passport characteristics of its metal. The negative impact of the rigid regime with cooling of the WWER-1000 reactor of Unit № 1, not taken into account by the operating organization (South-Ukrainian Nuclear Power Plant) when extending its designated resource / service life, is shown. timely to clarify complex factors, technical aspects and parameters, as well as – their possible negative effects on the safe operation of systems and elements of nuclear power plants.
{"title":"Expert express assessment of the impact of heat and mass transfer processes on the residual life of the WWER-1000 reactor vessel due to metal embrittlement","authors":"V. Popov, V. Mileikovskyi, O. O. Tryhub","doi":"10.32347/2409-2606.2022.41.39-49","DOIUrl":"https://doi.org/10.32347/2409-2606.2022.41.39-49","url":null,"abstract":"The WWER-1000 reactor is operated at 13 of the 15 operating power units of Ukraine's nuclear power plants (NPPs). Ensuring long-term and safe operation of such reactors is the basis for reliable operation of all 13 Ukrainian nuclear power plants units and the guarantor of Ukraine's energy security. The determining and leading factor influencing the safety and proper residual life of the WWER-1000 reactor vessel is the radiation embrittlement of the reactor steel. The consequences of radiation embrittlement of reactor steel are negatively manifested in emergencies with cooling of the core. This process itself – radiation embrittlement – accumulates constantly and gradually. Therefore, it is important to monitor it by periodically performing ongoing rapid assessments of the brittle strength of the WWER-1000 reactor vessel (along with other factors, including cyclic damage, as discussed in a previous publication). Therefore, it is important to use the calculated express methods of periodic assessment of the brittle strength of the WWER-1000 reactor vessel with guaranteed accuracy. The effectiveness of the approach is supported by low cost of resources – engineering staff, fast and relatively simplified use of computers and software. As an example and confirmation of the applicability of the proposed approach, an expert rapid assessment of the fragile strength and residual life of the reactor vessel of Unit № 1 of the South-Ukrainian Nuclear Power Plant was performed. This takes into account the actual, passport characteristics of its metal. The negative impact of the rigid regime with cooling of the WWER-1000 reactor of Unit № 1, not taken into account by the operating organization (South-Ukrainian Nuclear Power Plant) when extending its designated resource / service life, is shown. timely to clarify complex factors, technical aspects and parameters, as well as – their possible negative effects on the safe operation of systems and elements of nuclear power plants.","PeriodicalId":23499,"journal":{"name":"Ventilation, Illumination and Heat Gas Supply","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72838472","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}
Pub Date : 2022-01-17DOI: 10.32347/2409-2606.2022.40.50-56
Y. Franchuk
Gas produced at different deposits has different compositions, namely different amounts of methane, propane, nitrogen and so on. Different gas composition determines different physical and chemical characteristics of the gas, its heat of combustion, dew points on water and hydrocarbons, and Wobbe number. Previously, when using gas, little attention was paid to its characteristics, which are guided by the requirements of GOST 5542-87. With the restoration of Ukraine's independence and the transition to market conditions, attitudes toward gas have changed. Gas is a commodity and has a price. With the integration into the European Union, there was not only the implementation of European legislation but also the widespread use of advanced equipment and technologies in these countries. Gas will be metered in units of energy, not volume as before. This forces us to pay more attention to the quality of gas, set stricter requirements for its component composition, and monitor compliance with regulatory requirements in the process of transporting and supplying gas to the final consumer. GOST 5542-87 defined only a few quality parameters. Currently, the Code of Gas Transmission and Gas Distribution Systems, the Technical Regulation of Natural Gas and other regulations determine the quality of gas by more than 20 parameters that meet European standards. The methane content in the composition of natural gas must be at least 90 %, and other components of the gas are regulated. However, different deposits have different methane compositions. These limits range from 85 % to 99 % of methane. Different composition of natural gas affects not only its properties but also the reliability of the gas transmission and distribution system and affects the work of individual end-users. This problem is especially relevant when using gas appliances with high efficiency. The problem of gas quality is important for its metering in Ukraine and in settlements with other countries. The analysis of gas composition and quality during its transportation from the field to the consumer is carried out. It is determined that in the distribution part of the gas transmission system of Ukraine there are deviations in gas quality from regulatory requirements. This reduces the efficiency of some gas appliances and throttling equipment.
{"title":"Changes in the composition and quality of gas during its movement in the gas supply system","authors":"Y. Franchuk","doi":"10.32347/2409-2606.2022.40.50-56","DOIUrl":"https://doi.org/10.32347/2409-2606.2022.40.50-56","url":null,"abstract":"Gas produced at different deposits has different compositions, namely different amounts of methane, propane, nitrogen and so on. Different gas composition determines different physical and chemical characteristics of the gas, its heat of combustion, dew points on water and hydrocarbons, and Wobbe number. Previously, when using gas, little attention was paid to its characteristics, which are guided by the requirements of GOST 5542-87. With the restoration of Ukraine's independence and the transition to market conditions, attitudes toward gas have changed. Gas is a commodity and has a price. With the integration into the European Union, there was not only the implementation of European legislation but also the widespread use of advanced equipment and technologies in these countries. Gas will be metered in units of energy, not volume as before. This forces us to pay more attention to the quality of gas, set stricter requirements for its component composition, and monitor compliance with regulatory requirements in the process of transporting and supplying gas to the final consumer. GOST 5542-87 defined only a few quality parameters. Currently, the Code of Gas Transmission and Gas Distribution Systems, the Technical Regulation of Natural Gas and other regulations determine the quality of gas by more than 20 parameters that meet European standards. The methane content in the composition of natural gas must be at least 90 %, and other components of the gas are regulated. However, different deposits have different methane compositions. These limits range from 85 % to 99 % of methane. Different composition of natural gas affects not only its properties but also the reliability of the gas transmission and distribution system and affects the work of individual end-users. This problem is especially relevant when using gas appliances with high efficiency. The problem of gas quality is important for its metering in Ukraine and in settlements with other countries. The analysis of gas composition and quality during its transportation from the field to the consumer is carried out. It is determined that in the distribution part of the gas transmission system of Ukraine there are deviations in gas quality from regulatory requirements. This reduces the efficiency of some gas appliances and throttling equipment.","PeriodicalId":23499,"journal":{"name":"Ventilation, Illumination and Heat Gas Supply","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80549584","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}
Pub Date : 2022-01-17DOI: 10.32347/2409-2606.2022.40.43-49
Y. Burda, Y. Pivnenko, I. Redko, A. Cherednik, О. Priymak
Hybrid power plants were first proposed in the development of geothermal deposits in Kamchatka in 1964-66. The unit consists of two circuits, which use a steam turbine with a temperature of up to 200 ° C, with a degree of dryness of water vapor is 5% and a turbine on R12 refrigerant with a capacity of 5 MW. Electric power is 12 MW. Hybrid power plants are also used in metallurgy, cement and glass industries where the heat of exhaust gases with temperatures up to 350 ° C is used. A feature of the design calculations is the uncertainty of changes during the future life of some of the initial data, in particular, specific cost indicators. The available experience and the analysis of approaches to development of flowing parts of turbines have shown that depending on degree of expansion and expenses of working bodies the corresponding type of flowing part is chosen. The calculated studies of the three-circuit thermal circuit (at a discharge temperature of 350 ° C) showed that increasing the parameters of the working fluids is not always rational. Increasing the heat drop on the turbine leads to an increase in the number of turbine stages, but the cost of the working fluid is not enough to abandon the partial drive. The one-dimensional calculation does not show a complete picture of the flow in the flowing part of the turbine, which will have large losses from secondary flows and flows of the working fluid due to the low height of the blades and a high degree of partiality. The results also allow us to conclude that the most appropriate is the implementation of a double-circuit thermal scheme and increase the consumption of working fluids. Increasing the number of circuit elements and possible combinations of their connections, expanding the range of changes in the initial data, factors of systemicity and uncertainty significantly complicate the choice of the final version of the thermal circuit.
{"title":"Numerical simulation of parameters of the thermal scheme of the waste heat recovery system","authors":"Y. Burda, Y. Pivnenko, I. Redko, A. Cherednik, О. Priymak","doi":"10.32347/2409-2606.2022.40.43-49","DOIUrl":"https://doi.org/10.32347/2409-2606.2022.40.43-49","url":null,"abstract":"Hybrid power plants were first proposed in the development of geothermal deposits in Kamchatka in 1964-66. The unit consists of two circuits, which use a steam turbine with a temperature of up to 200 ° C, with a degree of dryness of water vapor is 5% and a turbine on R12 refrigerant with a capacity of 5 MW. Electric power is 12 MW. Hybrid power plants are also used in metallurgy, cement and glass industries where the heat of exhaust gases with temperatures up to 350 ° C is used. A feature of the design calculations is the uncertainty of changes during the future life of some of the initial data, in particular, specific cost indicators. The available experience and the analysis of approaches to development of flowing parts of turbines have shown that depending on degree of expansion and expenses of working bodies the corresponding type of flowing part is chosen. The calculated studies of the three-circuit thermal circuit (at a discharge temperature of 350 ° C) showed that increasing the parameters of the working fluids is not always rational. Increasing the heat drop on the turbine leads to an increase in the number of turbine stages, but the cost of the working fluid is not enough to abandon the partial drive. The one-dimensional calculation does not show a complete picture of the flow in the flowing part of the turbine, which will have large losses from secondary flows and flows of the working fluid due to the low height of the blades and a high degree of partiality. The results also allow us to conclude that the most appropriate is the implementation of a double-circuit thermal scheme and increase the consumption of working fluids. Increasing the number of circuit elements and possible combinations of their connections, expanding the range of changes in the initial data, factors of systemicity and uncertainty significantly complicate the choice of the final version of the thermal circuit.","PeriodicalId":23499,"journal":{"name":"Ventilation, Illumination and Heat Gas Supply","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87501449","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}
Pub Date : 2022-01-17DOI: 10.32347/2409-2606.2022.40.23-27
R. Dzhyoev
Cyclonic-vortex technology of solid fuel combustion allows to reduce the furnace volume of the boiler unit, dimensions and weight. Mixing of fuel particles and air in a swirling stream provides intensive heat exchange and fuel combustion in a limited furnace volume. The results of improving the thermal scheme of combustion of pulverized fuel (wood waste) in a circulating fluidized bed are presented. The results of numerical calculations showed the possibility of burning sawdust with a particle diameter of 25 μm to 750 μm. When the air-fuel mixture is supplied from the bottom of the furnace, and the secondary air from the top of the furnace, ash is removed in liquid form through a slot in the lower part of the furnace. It was found that with a sawdust moisture content of 10%, ash content Ac = 0.6%, a higher combustion heat of 17.7 MJ / kg, particle entrainment is 19.2 %, the degree of particle burnout is 92.5%, which requires afterburning of entrainment in a circulating boiling layer. One of the ways to improve Ukraine's fuel and energy balance is to use alternative sources of heat to natural gas, namely solid fuels or wood industry waste. It is necessary to involve specialized technologies for burning solid fuels. Currently, there is an incomplete theoretical and practical knowledge about the processes of burning wood waste.The use of natural gas as a source of thermal energy occupies a significant part of Ukraine's fuel and energy balance. To increase the share of solid fuels, it is necessary to study in more detail the processes of their combustion and the use of methods of intensification of heat transfer processes in the furnaces of solid fuel boilers. The results of numerical calculations showed that the use of vortex furnace instead of direct flow in the scheme CKS increases the residence time of particles in the furnace, which reduces the multiplicity of fuel circulation, reduce the size and weight of the furnace
{"title":"Scheme of incineration of wood waste in a furnace with a circulating boiling bed","authors":"R. Dzhyoev","doi":"10.32347/2409-2606.2022.40.23-27","DOIUrl":"https://doi.org/10.32347/2409-2606.2022.40.23-27","url":null,"abstract":"Cyclonic-vortex technology of solid fuel combustion allows to reduce the furnace volume of the boiler unit, dimensions and weight. Mixing of fuel particles and air in a swirling stream provides intensive heat exchange and fuel combustion in a limited furnace volume. The results of improving the thermal scheme of combustion of pulverized fuel (wood waste) in a circulating fluidized bed are presented. The results of numerical calculations showed the possibility of burning sawdust with a particle diameter of 25 μm to 750 μm. When the air-fuel mixture is supplied from the bottom of the furnace, and the secondary air from the top of the furnace, ash is removed in liquid form through a slot in the lower part of the furnace. It was found that with a sawdust moisture content of 10%, ash content Ac = 0.6%, a higher combustion heat of 17.7 MJ / kg, particle entrainment is 19.2 %, the degree of particle burnout is 92.5%, which requires afterburning of entrainment in a circulating boiling layer. One of the ways to improve Ukraine's fuel and energy balance is to use alternative sources of heat to natural gas, namely solid fuels or wood industry waste. It is necessary to involve specialized technologies for burning solid fuels. Currently, there is an incomplete theoretical and practical knowledge about the processes of burning wood waste.The use of natural gas as a source of thermal energy occupies a significant part of Ukraine's fuel and energy balance. To increase the share of solid fuels, it is necessary to study in more detail the processes of their combustion and the use of methods of intensification of heat transfer processes in the furnaces of solid fuel boilers. The results of numerical calculations showed that the use of vortex furnace instead of direct flow in the scheme CKS increases the residence time of particles in the furnace, which reduces the multiplicity of fuel circulation, reduce the size and weight of the furnace","PeriodicalId":23499,"journal":{"name":"Ventilation, Illumination and Heat Gas Supply","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88847950","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}
Pub Date : 2022-01-17DOI: 10.32347/2409-2606.2022.40.16-22
V. Norchak
Ukraine ranks seventh in the international list of countries by the number of coal reserves in the country. Optimal use of this natural resource is the key to active industrial development and the basis for increasing the country's energy independence. There are large deposits of coal on the territory of Ukraine, so historically this type of fuel has been the basis of the energy sector of the economy. Despite extensive experience, the optimal way to burn coal has not been established. Even minor changes in the design of solid fuel furnaces significantly affect the efficiency of the heat transfer process inside the boilers. Therefore, the study of various design features of furnaces is relevant and promising. The results of numerical calculation of the parameters of the process of burning brown coal in a vortex furnace with counter-swirling flows are presented. The fractional composition of the fuel varies from 25 μm to 250 μm. A comparison of fuel and air mixture supply schemes from the bottom of the furnace and from the top of the furnace is performed. It has been shown that the supply of fuel from the bottom of the furnace removes solid ash at the top of the furnace, leads to a more even distribution of flue gas temperatures within the furnace volume and reduces coke content in fuel particles during lignite combustion. The results of numerical simulation of brown coal combustion processes in a vortex furnace with counterflows show that among the three schemes considered, the third scheme with lower fuel supply and removal of solid ash from the top of the furnace has the best characteristics. In this case, 99.4% of the capture of particles is provided, the particles do not accumulate in the furnace volume due to the extraction of ash. However, the mechanical underburning of coke particles with a diameter of 25 μm to 250 mm, which is captured, is 8.1% and requires afterburning. The second scheme does not provide efficient combustion of coal due to the accumulation of particles in the furnace volume.
{"title":"Technological parameters of the combustion process of brown coal in a vortex furnace","authors":"V. Norchak","doi":"10.32347/2409-2606.2022.40.16-22","DOIUrl":"https://doi.org/10.32347/2409-2606.2022.40.16-22","url":null,"abstract":"Ukraine ranks seventh in the international list of countries by the number of coal reserves in the country. Optimal use of this natural resource is the key to active industrial development and the basis for increasing the country's energy independence. There are large deposits of coal on the territory of Ukraine, so historically this type of fuel has been the basis of the energy sector of the economy. Despite extensive experience, the optimal way to burn coal has not been established. Even minor changes in the design of solid fuel furnaces significantly affect the efficiency of the heat transfer process inside the boilers. Therefore, the study of various design features of furnaces is relevant and promising. The results of numerical calculation of the parameters of the process of burning brown coal in a vortex furnace with counter-swirling flows are presented. The fractional composition of the fuel varies from 25 μm to 250 μm. A comparison of fuel and air mixture supply schemes from the bottom of the furnace and from the top of the furnace is performed. It has been shown that the supply of fuel from the bottom of the furnace removes solid ash at the top of the furnace, leads to a more even distribution of flue gas temperatures within the furnace volume and reduces coke content in fuel particles during lignite combustion. The results of numerical simulation of brown coal combustion processes in a vortex furnace with counterflows show that among the three schemes considered, the third scheme with lower fuel supply and removal of solid ash from the top of the furnace has the best characteristics. In this case, 99.4% of the capture of particles is provided, the particles do not accumulate in the furnace volume due to the extraction of ash. However, the mechanical underburning of coke particles with a diameter of 25 μm to 250 mm, which is captured, is 8.1% and requires afterburning. The second scheme does not provide efficient combustion of coal due to the accumulation of particles in the furnace volume.","PeriodicalId":23499,"journal":{"name":"Ventilation, Illumination and Heat Gas Supply","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83068537","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}
Pub Date : 2022-01-17DOI: 10.32347/2409-2606.2022.40.28-36
G. Ratushniak, L. Lialiuk, O. Horiun
The use of innovative energy-saving structural units at the construction site will increase the energy efficiency of multi-storey residential buildings and reduce the cost of paying for energy consumed for heating in the cold season. The reliability of any system depends on the design, manufacture and operation. The durability and reliability of structures can be increased at the design stage, that is, during research, design, calculations and design development. A hierarchy of factors of influence on the reliability of ensuring energy efficiency of enclosing structures in the junction nodes has been developed. A tree of logical inference of hierarchical links has been built. The root of the tree of logical conclusions, as an integral indicator, allows, at the expert level, to provide intellectual support for the decisions made to choose a heat-insulating material and the design of the junction nodes. The analysis of the influence of factors on the reliability of ensuring the energy efficiency of the enclosing structures at thee junctions points using linguistic variables. In order to assess the reliability of thermal insulation material, expert knowledge bases were formed and fuzzy logical equations were written, as well as the response surface was constructed. Matrices of paired comparisons of scientific and technical design solutions for the terms “low”,”medium”, “high” have been created. Based on the solution of matrices of pairwise comparisons, accessory functions were obtained for all terms. The obtained results of membership functions are normalized by one by dividing by the highest degree of membership. The mathematical assessment of the process was carried out using out the Matlab software. The surfaces of the expert system for decision-making based on fuzzy inference are built.
{"title":"Analysis of the influence of factors on the reliability of energy efficiency of enclosing structures of adjustment units using linguistic variables","authors":"G. Ratushniak, L. Lialiuk, O. Horiun","doi":"10.32347/2409-2606.2022.40.28-36","DOIUrl":"https://doi.org/10.32347/2409-2606.2022.40.28-36","url":null,"abstract":"The use of innovative energy-saving structural units at the construction site will increase the energy efficiency of multi-storey residential buildings and reduce the cost of paying for energy consumed for heating in the cold season. The reliability of any system depends on the design, manufacture and operation. The durability and reliability of structures can be increased at the design stage, that is, during research, design, calculations and design development. A hierarchy of factors of influence on the reliability of ensuring energy efficiency of enclosing structures in the junction nodes has been developed. A tree of logical inference of hierarchical links has been built. The root of the tree of logical conclusions, as an integral indicator, allows, at the expert level, to provide intellectual support for the decisions made to choose a heat-insulating material and the design of the junction nodes. The analysis of the influence of factors on the reliability of ensuring the energy efficiency of the enclosing structures at thee junctions points using linguistic variables. In order to assess the reliability of thermal insulation material, expert knowledge bases were formed and fuzzy logical equations were written, as well as the response surface was constructed. Matrices of paired comparisons of scientific and technical design solutions for the terms “low”,”medium”, “high” have been created. Based on the solution of matrices of pairwise comparisons, accessory functions were obtained for all terms. The obtained results of membership functions are normalized by one by dividing by the highest degree of membership. The mathematical assessment of the process was carried out using out the Matlab software. The surfaces of the expert system for decision-making based on fuzzy inference are built.","PeriodicalId":23499,"journal":{"name":"Ventilation, Illumination and Heat Gas Supply","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74731373","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}
Pub Date : 2022-01-17DOI: 10.32347/2409-2606.2022.40.6-15
A. Makarov, M. Senchuk, A. Khodos, M. Kirienko
Two typical schemes of air heating in gas-oil air heaters (heat generators) are analyzed, the structural difference of which is characterized by the mutual location of the fire tube - combustion chamber and convective heating surface (chimneys). The improved constructive scheme of the developed high - temperature air heater - heat generator with air heating for technological processes of drying is described. The main technical and operational advantages of the accepted scheme of heating of air which differs in high economy and reliability are noted. New technical solutions in the developed design of the TG heat generator are considered for the purpose of increase of its efficiency and reliability at long operation. The adoption of these decisions on the basis of laboratory and computational research is substantiated. The scheme of the fire stand on studying the process of heat removal from heat-stressed heating surfaces by radiation-convective heat transfer with the use of heat-absorbing screens is given. Designed cooling systems for heat pipes of heat generators are described on the basis of bench researches and the calculation model is developed. The calculated dependences of the change in the temperature of the metal of the heated walls on the velocity of the air flow in a single channel and on the width of the double air channel with a heat-absorbing screen are given. The results of calculation researches for the purpose of optimization of a convective surface of heating and entrance sites of chimneys in the form of dependences of change are shown: length of convective packages depending on speed of flue gases; temperature of gases, metal of walls and air on the initial section of chimneys at various options of its configuration. Patented technical solutions in the designs of industrially implemented high-temperature air heaters - gas heat generators TG-0.95-200, TG-1.9-200 and ТГ-2,4-200 with an air heating temperature of 200 oC have been implemented. Their high efficiency and reliability during many years of operation as a part of drying installations at the enterprises of the food industry of Ukraine, Belarus, the Russian Federation, Azerbaijan, Uzbekistan, Turkmenistan, Kyrgyzstan, Poland are confirmed.
{"title":"Improving the efficiency of the technological scheme of industrial high-temperature air heater","authors":"A. Makarov, M. Senchuk, A. Khodos, M. Kirienko","doi":"10.32347/2409-2606.2022.40.6-15","DOIUrl":"https://doi.org/10.32347/2409-2606.2022.40.6-15","url":null,"abstract":"Two typical schemes of air heating in gas-oil air heaters (heat generators) are analyzed, the structural difference of which is characterized by the mutual location of the fire tube - combustion chamber and convective heating surface (chimneys). The improved constructive scheme of the developed high - temperature air heater - heat generator with air heating for technological processes of drying is described. The main technical and operational advantages of the accepted scheme of heating of air which differs in high economy and reliability are noted. New technical solutions in the developed design of the TG heat generator are considered for the purpose of increase of its efficiency and reliability at long operation. The adoption of these decisions on the basis of laboratory and computational research is substantiated. The scheme of the fire stand on studying the process of heat removal from heat-stressed heating surfaces by radiation-convective heat transfer with the use of heat-absorbing screens is given. Designed cooling systems for heat pipes of heat generators are described on the basis of bench researches and the calculation model is developed. The calculated dependences of the change in the temperature of the metal of the heated walls on the velocity of the air flow in a single channel and on the width of the double air channel with a heat-absorbing screen are given. The results of calculation researches for the purpose of optimization of a convective surface of heating and entrance sites of chimneys in the form of dependences of change are shown: length of convective packages depending on speed of flue gases; temperature of gases, metal of walls and air on the initial section of chimneys at various options of its configuration. Patented technical solutions in the designs of industrially implemented high-temperature air heaters - gas heat generators TG-0.95-200, TG-1.9-200 and ТГ-2,4-200 with an air heating temperature of 200 oC have been implemented. Their high efficiency and reliability during many years of operation as a part of drying installations at the enterprises of the food industry of Ukraine, Belarus, the Russian Federation, Azerbaijan, Uzbekistan, Turkmenistan, Kyrgyzstan, Poland are confirmed.","PeriodicalId":23499,"journal":{"name":"Ventilation, Illumination and Heat Gas Supply","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84849886","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}
Pub Date : 2022-01-17DOI: 10.32347/2409-2606.2022.40.37-42
B. Basok, B. Davydenko, V. Novikov, M. Novitska
In the heat balance of buildings, the main heat loss occurs through enclosing structures. Determining the heat transfer coefficients on the exterior facades of buildings is not an easy procedure, as they depend on a wide range of parameters: wind speed in the surface atmosphere, wind direction relative to the orientation of facades, surface orientation relative to wind, surface angle relative to the ground plane, type terrain, the impact of adjacent buildings, surface texture, surface and air temperature differences, surface size and aspect ratio, etc. The paper presents the results of a numerical study of heat transfer from the outer surfaces of separately located structures in the surface layer of the atmosphere. Schematic models of the building have the same heat transfer surface area, but different heights and lengths. CFD-modeling of heat transfer of buildings in the wind flow in a three-dimensional setting allowed to establish some features of heat transfer of enclosing structures depending on the height of the building and the characteristics of the wind flow. In particular, it is shown that the average surface values of heat flux density increase with increasing building height. The results of the calculation of the average heat flux density on the surface of buildings indicate its dependence on the height of this building. This dependence is observed only for houses with a height of less than 30 m. For taller houses, this dependence is insignificant. The local values of heat transfer coefficients on the windward and leeward facades of the building obtained as a result of modeling indicate incorrect application of heat transfer coefficient values αк = 23 W / (m2 ∙ K) for construction practice for external surfaces of enclosing structures. For windward facades, a polynomial model for the heat transfer coefficient is more suitable, and for leeward ones, the Frank formula for αk.
在建筑物的热平衡中，主要的热损失是通过围护结构发生的。确定建筑物外立面的传热系数并不是一个简单的过程，因为它们取决于一系列参数:地面大气中的风速、相对于立面朝向的风向、相对于风的表面朝向、相对于地面平面的表面角度、地形类型、相邻建筑物的影响、表面纹理、表面和空气温差、表面尺寸和宽高比等。本文介绍了大气表层中不同位置结构的外表面传热的数值研究结果。该建筑的示意图模型具有相同的传热表面积，但高度和长度不同。在三维环境中对建筑物在气流中的传热进行cfd建模，可以根据建筑物的高度和气流的特征建立封闭结构的传热特征。特别是，热流密度的平均表面值随着建筑高度的增加而增加。计算结果表明，建筑物表面平均热流密度与建筑物高度有关。这种相关性仅在高度小于30米的房屋中观察到。对于较高的房屋，这种依赖是微不足道的。通过建模得到的建筑物迎风面和背风面局部传热系数值表明，在围护结构外表面的施工实践中，传热系数值α _ (_) = 23 W / (m2∙K)的应用是不正确的。对于迎风立面，换热系数的多项式模型更合适，对于背风立面，αk的Frank公式更合适。
{"title":"Influence of architectural features of buildings on heat losses from their facades","authors":"B. Basok, B. Davydenko, V. Novikov, M. Novitska","doi":"10.32347/2409-2606.2022.40.37-42","DOIUrl":"https://doi.org/10.32347/2409-2606.2022.40.37-42","url":null,"abstract":"In the heat balance of buildings, the main heat loss occurs through enclosing structures. Determining the heat transfer coefficients on the exterior facades of buildings is not an easy procedure, as they depend on a wide range of parameters: wind speed in the surface atmosphere, wind direction relative to the orientation of facades, surface orientation relative to wind, surface angle relative to the ground plane, type terrain, the impact of adjacent buildings, surface texture, surface and air temperature differences, surface size and aspect ratio, etc. The paper presents the results of a numerical study of heat transfer from the outer surfaces of separately located structures in the surface layer of the atmosphere. Schematic models of the building have the same heat transfer surface area, but different heights and lengths. CFD-modeling of heat transfer of buildings in the wind flow in a three-dimensional setting allowed to establish some features of heat transfer of enclosing structures depending on the height of the building and the characteristics of the wind flow. In particular, it is shown that the average surface values of heat flux density increase with increasing building height. The results of the calculation of the average heat flux density on the surface of buildings indicate its dependence on the height of this building. This dependence is observed only for houses with a height of less than 30 m. For taller houses, this dependence is insignificant. The local values of heat transfer coefficients on the windward and leeward facades of the building obtained as a result of modeling indicate incorrect application of heat transfer coefficient values αк = 23 W / (m2 ∙ K) for construction practice for external surfaces of enclosing structures. For windward facades, a polynomial model for the heat transfer coefficient is more suitable, and for leeward ones, the Frank formula for αk.","PeriodicalId":23499,"journal":{"name":"Ventilation, Illumination and Heat Gas Supply","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89294102","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}
Pub Date : 2021-12-06DOI: 10.32347/2409-2606.2021.39.53-60
V. Cherednikov, O. Cherednikova, D. Guzyk
The article discusses the need to solve the problem of increasing the temperature limits of the operation of the cooling system of the internal combustion engine (ICE) of the helicopter. This issue arose from the fact that during the operation of the helicopter on the territory of African countries with a hot climate, the engine overheated. The use of helicopters in these conditions was due to the demand in the aviation market. To solve the problem, new elements of the cooling system were selected, i.e. radiator and two types of fans. The research was aimed at increasing the heat transfer from the radiators of the cooling system by increasing the size of the radiator and increasing the air flow rate through the radiator. 3D modeling, design of a new cooling system (CO), and then design of CO in two versions with TEMIC and SPAL fans were done. First, ground and flight tests for two prototypes in a temperate climate were done, as a result of which a prototype with the best performance parameters was determined. During the tests the equipment and measuring instruments were used: voltmeter, ammeter, voltmeter; shunt; motor tester with the ability to transfer data via Bluetooth; smartphone with OpenDiag software installed, which is included and connected to the motor tester via Bluetooth, helicopter objective control system, flight data registration system, equipment and devices normally installed on the helicopter. For flight tests in hot climates, a new cooling system with a SPAL fan was used, these tests lasted three days. This article describes the final stage of a series of tests for the effectiveness of the cooling system of a helicopter and an analysis of the results obtained with confirmation of the final achievement of the set goals, i.e. raising the upper temperature limit of the outside air for the safe operation of the helicopter.
{"title":"Testing the cooling system of the helicopter internal combustion engine in hot climates","authors":"V. Cherednikov, O. Cherednikova, D. Guzyk","doi":"10.32347/2409-2606.2021.39.53-60","DOIUrl":"https://doi.org/10.32347/2409-2606.2021.39.53-60","url":null,"abstract":"The article discusses the need to solve the problem of increasing the temperature limits of the operation of the cooling system of the internal combustion engine (ICE) of the helicopter. This issue arose from the fact that during the operation of the helicopter on the territory of African countries with a hot climate, the engine overheated. The use of helicopters in these conditions was due to the demand in the aviation market. To solve the problem, new elements of the cooling system were selected, i.e. radiator and two types of fans. The research was aimed at increasing the heat transfer from the radiators of the cooling system by increasing the size of the radiator and increasing the air flow rate through the radiator. 3D modeling, design of a new cooling system (CO), and then design of CO in two versions with TEMIC and SPAL fans were done. First, ground and flight tests for two prototypes in a temperate climate were done, as a result of which a prototype with the best performance parameters was determined. During the tests the equipment and measuring instruments were used: voltmeter, ammeter, voltmeter; shunt; motor tester with the ability to transfer data via Bluetooth; smartphone with OpenDiag software installed, which is included and connected to the motor tester via Bluetooth, helicopter objective control system, flight data registration system, equipment and devices normally installed on the helicopter. For flight tests in hot climates, a new cooling system with a SPAL fan was used, these tests lasted three days. This article describes the final stage of a series of tests for the effectiveness of the cooling system of a helicopter and an analysis of the results obtained with confirmation of the final achievement of the set goals, i.e. raising the upper temperature limit of the outside air for the safe operation of the helicopter.","PeriodicalId":23499,"journal":{"name":"Ventilation, Illumination and Heat Gas Supply","volume":"207 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76537063","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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