Pub Date : 2023-12-04DOI: 10.24425/ather.2023.147540
{"title":"Investigation of thermal-flow characteristics of the minichannel heat exchanger of variable louvers height","authors":"","doi":"10.24425/ather.2023.147540","DOIUrl":"https://doi.org/10.24425/ather.2023.147540","url":null,"abstract":"","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":"6 16","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138603592","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}
Improvement in the exegetic efficiency of a solar air heater (SAH) can be done by enhancing the rate of heat transfer. In this work, the exergetic efficiency optimization of an artificially roughened solar air heater having an inverted L-shape rib has been performed. The numerical analysis of the exergetic performance of the solar air heater was carried out at a constant heat flux of 1000 W/m 2 . The study was conducted to investigate the effect of different relative roughness pitch (7.14–17.86) on the exergy losses, under the Reynolds number range of 3000 to 18 000. The roughness parameter of this geometry has been optimized and found to be among functional operating parameters like average solar intensity and temperature rise across the collector. The optimized value of relative roughness pitch is 17.86 at the isolation of 1000 W/m 2 , and the parameter of temperature rise ranges from 0.005 to 0.04.
{"title":"Exergetic performance analysis of solar air heater with inverted L-shape ribs as roughness element","authors":"Manmohan Chaudhari, Sohan Lal, Sharma, Ajoy Debbarma","doi":"10.24425/ather.2023.147546","DOIUrl":"https://doi.org/10.24425/ather.2023.147546","url":null,"abstract":"Improvement in the exegetic efficiency of a solar air heater (SAH) can be done by enhancing the rate of heat transfer. In this work, the exergetic efficiency optimization of an artificially roughened solar air heater having an inverted L-shape rib has been performed. The numerical analysis of the exergetic performance of the solar air heater was carried out at a constant heat flux of 1000 W/m 2 . The study was conducted to investigate the effect of different relative roughness pitch (7.14–17.86) on the exergy losses, under the Reynolds number range of 3000 to 18 000. The roughness parameter of this geometry has been optimized and found to be among functional operating parameters like average solar intensity and temperature rise across the collector. The optimized value of relative roughness pitch is 17.86 at the isolation of 1000 W/m 2 , and the parameter of temperature rise ranges from 0.005 to 0.04.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":"77 7","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138604504","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 : 2023-12-04DOI: 10.24425/ather.2023.147544
{"title":"Off-grid power supply – the future of district heating","authors":"","doi":"10.24425/ather.2023.147544","DOIUrl":"https://doi.org/10.24425/ather.2023.147544","url":null,"abstract":"","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":"11 10","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138603139","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 : 2023-12-04DOI: 10.24425/ather.2023.147536
Raman Kumar, Singh, Prakash Chandra
The present work is aimed at geometrical optimization and optical analysis of a small-sized parabolic trough collector (PTC). Improving the performance of parabolic trough collectors can greatly justify the use of solar energy. An optimized curvature geometry, the location of the absorber tube, and the heat flux distribution along the circumference of the absorber tube are major features in the geometric optimization and optical modelling of parabolic trough collectors. Rim angle, aperture width, the diameter of the absorber tube, receiver position, and the optimum value of heat flux are the major parameters considered in this work for geometrical and optical analysis. The Monte Carlo ray tracing method has been adopted for analysis. The non-uniform heat flux distribution profile obtained from optical analysis of the proposed parabolic trough collector has been compared with the profile available in the literature, and good agreement has been obtained, which proves the feasibility and reliability of the model and method used for this study. An experimental new small-sized parabolic trough collector has been fabricated for the optimized rim angle of 90 deg after a successful laser light feasibility test. The effect of the absorber tube position along the optical axis on the heat flux profile was analysed and found to be substantial. Furthermore, the sensitivity analysis of the parabolic trough collector using the software applied has been discussed separately.
{"title":"Geometrical and optical analysis of small-sized parabolic trough collector using ray tracing tool SolTrace","authors":"Raman Kumar, Singh, Prakash Chandra","doi":"10.24425/ather.2023.147536","DOIUrl":"https://doi.org/10.24425/ather.2023.147536","url":null,"abstract":"The present work is aimed at geometrical optimization and optical analysis of a small-sized parabolic trough collector (PTC). Improving the performance of parabolic trough collectors can greatly justify the use of solar energy. An optimized curvature geometry, the location of the absorber tube, and the heat flux distribution along the circumference of the absorber tube are major features in the geometric optimization and optical modelling of parabolic trough collectors. Rim angle, aperture width, the diameter of the absorber tube, receiver position, and the optimum value of heat flux are the major parameters considered in this work for geometrical and optical analysis. The Monte Carlo ray tracing method has been adopted for analysis. The non-uniform heat flux distribution profile obtained from optical analysis of the proposed parabolic trough collector has been compared with the profile available in the literature, and good agreement has been obtained, which proves the feasibility and reliability of the model and method used for this study. An experimental new small-sized parabolic trough collector has been fabricated for the optimized rim angle of 90 deg after a successful laser light feasibility test. The effect of the absorber tube position along the optical axis on the heat flux profile was analysed and found to be substantial. Furthermore, the sensitivity analysis of the parabolic trough collector using the software applied has been discussed separately.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":"54 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138602064","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}
Conventional fuels are the primary source of pollution. Switching towards clean energy becomes increasingly necessary for sustainable development. Electric vehicles are the most suitable alternative for the future of the automobile industry. The battery, being the power source, is the critical element of electric vehicles. However, its charging and discharging rates have always been a question. The discharge rate depends upon various factors such as vehicle load, temperature gradient, surface inclination, terrain, tyre pressure, and vehicle speed. In this work, a 20 Ah, 13S-8P configured lithium-ion battery, developed specifically for a supermileage custom vehicle, is used for experimentation. The abovementioned factors have been analyzed to check the vehicle’s overall performance in different operating conditions, and their effects have been investigated against the battery’s discharge rate. It has been observed that the discharge rate remains unaffected by the considered temperature difference. However, overheating the battery results in thermal runaway, damaging and reducing its life. Increasing the number of brakes to 15, the impact on the discharge rate is marginal; however, if the
{"title":"Performance analysis of a lithium-ion battery of an electric vehicle under various driving conditions","authors":"Shreya Dhawan, Aanchal Sabharwal, Rupali Prasad, Shreya Shreya, Aarushi Gupta, Yusuf Parvez","doi":"10.24425/ather.2023.147541","DOIUrl":"https://doi.org/10.24425/ather.2023.147541","url":null,"abstract":"Conventional fuels are the primary source of pollution. Switching towards clean energy becomes increasingly necessary for sustainable development. Electric vehicles are the most suitable alternative for the future of the automobile industry. The battery, being the power source, is the critical element of electric vehicles. However, its charging and discharging rates have always been a question. The discharge rate depends upon various factors such as vehicle load, temperature gradient, surface inclination, terrain, tyre pressure, and vehicle speed. In this work, a 20 Ah, 13S-8P configured lithium-ion battery, developed specifically for a supermileage custom vehicle, is used for experimentation. The abovementioned factors have been analyzed to check the vehicle’s overall performance in different operating conditions, and their effects have been investigated against the battery’s discharge rate. It has been observed that the discharge rate remains unaffected by the considered temperature difference. However, overheating the battery results in thermal runaway, damaging and reducing its life. Increasing the number of brakes to 15, the impact on the discharge rate is marginal; however, if the","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":"14 6","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138603461","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 : 2023-12-04DOI: 10.24425/ather.2023.147547
Jelena Bošnjak, Natalia Bodrozic, Coko Miso, Jurcevic Branko Klarin, Sandro Nižetić
The design of suitable thermophysical properties of reinforced ice as well as employing the novel material in feasible ways represent key aspects towards alternative building sustainability. In this overview research studies dealing with reinforced ice structures have been presented with an emphasis on construction parameters and reinforcement materials of the structures. The main focus of the study is directed to the identification of the main issues related to the construction of reinforced ice structures as well as the environmental and economic impact of such structures. Obtained research data shows that the compressive, tensile, and bending strength of reinforced ice can be increased up to 6 times compared to plain ice. The application of reinforcement materials decreases creep rate, enhances ductility, and reduces brittle behaviour of ice. Assessed reinforced ice structures were mainly found to be environmentally friendly and economically viable. However, in most of the analysed studies construction parameters and physical properties were not defined precisely. The conducted overview indicates the necessity for more comprehensive and more accurate data regarding reinforced ice construction, applied methods, and processes, and preparation of ice composites in general.
{"title":"Use of reinforced ice as alternative building material in cold regions: an overview","authors":"Jelena Bošnjak, Natalia Bodrozic, Coko Miso, Jurcevic Branko Klarin, Sandro Nižetić","doi":"10.24425/ather.2023.147547","DOIUrl":"https://doi.org/10.24425/ather.2023.147547","url":null,"abstract":"The design of suitable thermophysical properties of reinforced ice as well as employing the novel material in feasible ways represent key aspects towards alternative building sustainability. In this overview research studies dealing with reinforced ice structures have been presented with an emphasis on construction parameters and reinforcement materials of the structures. The main focus of the study is directed to the identification of the main issues related to the construction of reinforced ice structures as well as the environmental and economic impact of such structures. Obtained research data shows that the compressive, tensile, and bending strength of reinforced ice can be increased up to 6 times compared to plain ice. The application of reinforcement materials decreases creep rate, enhances ductility, and reduces brittle behaviour of ice. Assessed reinforced ice structures were mainly found to be environmentally friendly and economically viable. However, in most of the analysed studies construction parameters and physical properties were not defined precisely. The conducted overview indicates the necessity for more comprehensive and more accurate data regarding reinforced ice construction, applied methods, and processes, and preparation of ice composites in general.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":"31 47","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138601276","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}
For the sake of exploring the thermodynamic characteristics of hybrid ceramic bearings with metal inner rings in the application process, we established the mathematical model of bearings with metal inner rings based on the thermodynamics of bearings. The heat of the bearings, inner and outer raceway, and the deformation of bearings were calculated by the thermodynamic model. We used the bearing life testing machine to test the bearing load and speed. The consequences indicate that the temperature stability time of a hybrid ceramic bearing with the metal inner ring is about 6 hours after loading, and its temperature is about 1–2 ◦ C higher than that of a metal bearing. Under the condition of a certain speed, the stable temperature of bearing operation improves with the enlargement of the load. Under the condition of a certain load, the bearing temperature also improves with the enlargement of bearing speed. The overall temperature trend of the bearing outer ring is unanimous with the overall temperature value calculated by the model. The maximum error is between 2.2 and 2.4 ◦ C. The thermodynamic analysis of hybrid bearings with metal inner rings is conducive to a better study of the effect of bearing material characteristics on bearing performance.
{"title":"Thermodynamic analysis of hybrid ceramic bearings with metal inner rings","authors":"Jian Sun, Guangxiang Zhang, Junxing Tian, Yusheng Zhu","doi":"10.24425/ather.2023.147538","DOIUrl":"https://doi.org/10.24425/ather.2023.147538","url":null,"abstract":"For the sake of exploring the thermodynamic characteristics of hybrid ceramic bearings with metal inner rings in the application process, we established the mathematical model of bearings with metal inner rings based on the thermodynamics of bearings. The heat of the bearings, inner and outer raceway, and the deformation of bearings were calculated by the thermodynamic model. We used the bearing life testing machine to test the bearing load and speed. The consequences indicate that the temperature stability time of a hybrid ceramic bearing with the metal inner ring is about 6 hours after loading, and its temperature is about 1–2 ◦ C higher than that of a metal bearing. Under the condition of a certain speed, the stable temperature of bearing operation improves with the enlargement of the load. Under the condition of a certain load, the bearing temperature also improves with the enlargement of bearing speed. The overall temperature trend of the bearing outer ring is unanimous with the overall temperature value calculated by the model. The maximum error is between 2.2 and 2.4 ◦ C. The thermodynamic analysis of hybrid bearings with metal inner rings is conducive to a better study of the effect of bearing material characteristics on bearing performance.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":"34 27","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138601393","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 : 2023-12-04DOI: 10.24425/ather.2023.147549
{"title":"Effect of artificial coarseness on the performance of rectangular solar air heater duct: a comparative study","authors":"","doi":"10.24425/ather.2023.147549","DOIUrl":"https://doi.org/10.24425/ather.2023.147549","url":null,"abstract":"","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":"28 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138602751","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 : 2023-12-04DOI: 10.24425/ather.2023.147539
Asmaa Ali, Hussein
The present work comprises a numerical analysis using the Ansys program to solve the problem of combined free-forced convection around a circular cylinder located in a horizontal lid-driven trapezoidal en-closure. The enclosure is filled with water. The upper moving wall and lower fixed wall are cold at a constant temperature, whereas the inclined walls are adiabatically insulated. The uniformly heated cylinder is located at different positions in the cavity. The study covers three values of Richardson number (0.01, 1, and 10). The results show that the streamlines and isotherms in the enclosure, the Nusselt number and friction factor in the moving wall, hot wall and bottom wall are strongly dependent on the position of the inner hot cylinder. The results are validated with previous work, and the comparison gives good agreement.
{"title":"Mixed convection heat transfer in trapezoidal lid-driven cavity with uniformly heated inner circular cylinder","authors":"Asmaa Ali, Hussein","doi":"10.24425/ather.2023.147539","DOIUrl":"https://doi.org/10.24425/ather.2023.147539","url":null,"abstract":"The present work comprises a numerical analysis using the Ansys program to solve the problem of combined free-forced convection around a circular cylinder located in a horizontal lid-driven trapezoidal en-closure. The enclosure is filled with water. The upper moving wall and lower fixed wall are cold at a constant temperature, whereas the inclined walls are adiabatically insulated. The uniformly heated cylinder is located at different positions in the cavity. The study covers three values of Richardson number (0.01, 1, and 10). The results show that the streamlines and isotherms in the enclosure, the Nusselt number and friction factor in the moving wall, hot wall and bottom wall are strongly dependent on the position of the inner hot cylinder. The results are validated with previous work, and the comparison gives good agreement.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":"23 3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138602784","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 : 2023-12-04DOI: 10.24425/ather.2023.147537
Maja Kaszuba
The paper presents a thermodynamic analysis of the integration of a cryogenic air separation unit into a negative CO 2 emission gas power plant. The power cycle utilizes sewage sludge as fuel so this system fits into the innovative idea of bioenergy with carbon capture and storage. A cryogenic air separation unit integrated with the power plant was simulated in professional plant engineering and thermodynamic process analysis software. Two cases of the thermodynamic cycle have been studied, namely with the exhaust bleed for fuel treatment and without it. The results of calculations indicate that the net efficiencies of the negative CO 2 emission gas power plant reach 27.05% (combustion in 95.0% pure oxygen) and 24.57% (combustion in 99.5% pure oxygen) with the bleed. The efficiencies of the cycle without the bleed are 29.26% and 27.0% for combustion in 95.0% pure oxygen and 99.5% pure oxygen, respectively. For the mentioned cycle, the calculated energy penalty of oxygen production was 0.235 MWh/kgO 2 for the lower purity value. However, for higher purity namely 99.5%, the energy penalty of oxygen production for the thermodynamic cycle including the bleed and excluding the bleed was indicated 0.346 and 0.347 MWh/kgO 2 , respectively. Additionally, the analysis of the oxygen purity impact on the carbon dioxide purity at the end of the carbon capture and storage installation shows that for the case with the bleed, CO 2 purities are 93.8% and 97.6%, and excluding the bleed they are 93.8% and 97.8%, for the mentioned oxygen purities respectively. Insertion of the
{"title":"Performance of cryogenic oxygen production unit with exhaust gas bleed for sewage sludge gasification and different oxygen purities","authors":"Maja Kaszuba","doi":"10.24425/ather.2023.147537","DOIUrl":"https://doi.org/10.24425/ather.2023.147537","url":null,"abstract":"The paper presents a thermodynamic analysis of the integration of a cryogenic air separation unit into a negative CO 2 emission gas power plant. The power cycle utilizes sewage sludge as fuel so this system fits into the innovative idea of bioenergy with carbon capture and storage. A cryogenic air separation unit integrated with the power plant was simulated in professional plant engineering and thermodynamic process analysis software. Two cases of the thermodynamic cycle have been studied, namely with the exhaust bleed for fuel treatment and without it. The results of calculations indicate that the net efficiencies of the negative CO 2 emission gas power plant reach 27.05% (combustion in 95.0% pure oxygen) and 24.57% (combustion in 99.5% pure oxygen) with the bleed. The efficiencies of the cycle without the bleed are 29.26% and 27.0% for combustion in 95.0% pure oxygen and 99.5% pure oxygen, respectively. For the mentioned cycle, the calculated energy penalty of oxygen production was 0.235 MWh/kgO 2 for the lower purity value. However, for higher purity namely 99.5%, the energy penalty of oxygen production for the thermodynamic cycle including the bleed and excluding the bleed was indicated 0.346 and 0.347 MWh/kgO 2 , respectively. Additionally, the analysis of the oxygen purity impact on the carbon dioxide purity at the end of the carbon capture and storage installation shows that for the case with the bleed, CO 2 purities are 93.8% and 97.6%, and excluding the bleed they are 93.8% and 97.8%, for the mentioned oxygen purities respectively. Insertion of the","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":"21 15","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138603265","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：