Pub Date : 2024-01-02DOI: 10.18186/thermal.1448578
Adnan M. Hussein, Afrah Awad, Hussein Hayder Mohammed Ali
In this research, flat plate solar collectors (FPSC) were studied due to their simplicity, low maintenance, and cost-effectiveness. The study focused on comparing FPSC thermal performance using CuO/H2O nanofluids. Experiments were conducted over three months during the Iraqi weather conditions (January, February, and March) with carefully selected nanoparticle concentrations. Data was collected from 9 A.M. to 3 P.M., using various mass flow rates (ranging from 0.003 to 0.076 kg/s). Results showed a direct correlation between temperature and nanoparticle concentrations, with the highest outlet temperature (50°C) observed at 3 P.M. for 1% CuO-water nanofluid. Notably, at 1 P.M. in March, the 1% CuO-water nanofluid exhibited a 32% increase in collector thermal efficiency, surpassing pure water by 11.3%. This would improve the performance of FPSC by achieving higher efficiency increments. These improvements were attributed to the unique physical properties of nanoparticles, their increased surface area, and higher thermal conductivity. The study determined that the optimum nanofluid concentration for superior collector efficiency was 1%.
{"title":"Evaluation of the thermal efficiency of nanofluid flows in flat plate solar collector","authors":"Adnan M. Hussein, Afrah Awad, Hussein Hayder Mohammed Ali","doi":"10.18186/thermal.1448578","DOIUrl":"https://doi.org/10.18186/thermal.1448578","url":null,"abstract":"In this research, flat plate solar collectors (FPSC) were studied due to their simplicity, low maintenance, and cost-effectiveness. The study focused on comparing FPSC thermal performance using CuO/H2O nanofluids. Experiments were conducted over three months during the Iraqi weather conditions (January, February, and March) with carefully selected nanoparticle concentrations. Data was collected from 9 A.M. to 3 P.M., using various mass flow rates (ranging from 0.003 to 0.076 kg/s). Results showed a direct correlation between temperature and nanoparticle concentrations, with the highest outlet temperature (50°C) observed at 3 P.M. for 1% CuO-water nanofluid. Notably, at 1 P.M. in March, the 1% CuO-water nanofluid exhibited a 32% increase in collector thermal efficiency, surpassing pure water by 11.3%. This would improve the performance of FPSC by achieving higher efficiency increments. These improvements were attributed to the unique physical properties of nanoparticles, their increased surface area, and higher thermal conductivity. The study determined that the optimum nanofluid concentration for superior collector efficiency was 1%.","PeriodicalId":45841,"journal":{"name":"Journal of Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140515598","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 : 2023-10-17DOI: 10.18186/thermal.1372390
Swati MOR, Niraj KUMAR, Gulshan SACHDEVA
In this study, roughness in the form of multi-V ribs having trapezoidal slots were crafted over the surface of absorber plate for enhancing the heat transfer rate in a solar air heater. An ex-perimental setup was designed and fabricated for demonstrating the performance of this plate with respect to smooth absorber plate. The setup has a double glazed-double pass air flow arrangement. The experiments were conducted under Indian climatic conditions (Latitude = 28.53˚N and Longitude = 77.39˚E) in September and October 2021 at various rates of air flow through the duct. The results of the roughened absorber plate were compared with the smooth absorber plate. It shows that the multi-V ribs with trapezoidal slots have higher efficacy as compared to smooth absorber plate in the order of 10.42% at an air flow rate of 0.078 kg/s. In addition, the present data of proposed roughness were also compared with data of various roughness available in the literature. It was found that the maximum thermo-hydraulic perfor-mance parameter of the proposed roughness texture is higher than other shapes of roughness texture. It was also found that the combination of double-glass cover and double-pass arrange-ment with the proposed roughness geometry increases the efficiency of the solar air heater at least by one order of the present solar air heating system.
{"title":"Experimental investigation of double-glazed double-pass solar airheater (DG-DPSAH) with multi-v ribs having trapezoidal roughness geometry","authors":"Swati MOR, Niraj KUMAR, Gulshan SACHDEVA","doi":"10.18186/thermal.1372390","DOIUrl":"https://doi.org/10.18186/thermal.1372390","url":null,"abstract":"In this study, roughness in the form of multi-V ribs having trapezoidal slots were crafted over the surface of absorber plate for enhancing the heat transfer rate in a solar air heater. An ex-perimental setup was designed and fabricated for demonstrating the performance of this plate with respect to smooth absorber plate. The setup has a double glazed-double pass air flow arrangement. The experiments were conducted under Indian climatic conditions (Latitude = 28.53˚N and Longitude = 77.39˚E) in September and October 2021 at various rates of air flow through the duct. The results of the roughened absorber plate were compared with the smooth absorber plate. It shows that the multi-V ribs with trapezoidal slots have higher efficacy as compared to smooth absorber plate in the order of 10.42% at an air flow rate of 0.078 kg/s. In addition, the present data of proposed roughness were also compared with data of various roughness available in the literature. It was found that the maximum thermo-hydraulic perfor-mance parameter of the proposed roughness texture is higher than other shapes of roughness texture. It was also found that the combination of double-glass cover and double-pass arrange-ment with the proposed roughness geometry increases the efficiency of the solar air heater at least by one order of the present solar air heating system.","PeriodicalId":45841,"journal":{"name":"Journal of Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135944145","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}
Solar air collectors have been used in a variety of industrial applications, prompting a study and summary of various studies on the topic. Solar collectors’ exceptional energy conversion and storage outputs have piqued curiosity in the field of energy research. The current review study focuses on solar thermal application advancements and provides an overview of thermal energy storage devices and solar collectors. This paper presents and discusses a variety of solar collectors, both concentrating and non-concentrating. The energy storage media utilized in these plants, phase change material with melting temperatures exceeding 300°C, was exam-ined. The goal of this study is to provide the necessary information for advanced investiga-tions in the development of cost-effective high-temperature thermal storage systems. Finally, a summary of the presentation, as well as potential solar power plants are reviewed.
{"title":"Heat transfer enhancement and applications of thermal energy storage techniques on solar air collectors: A review","authors":"Kafel AZEEZ, Riyadh Ibraheem AHMED, Zain Alabdeen OBAID, Itimad DJ AZZAWI","doi":"10.18186/thermal.1377246","DOIUrl":"https://doi.org/10.18186/thermal.1377246","url":null,"abstract":"Solar air collectors have been used in a variety of industrial applications, prompting a study and summary of various studies on the topic. Solar collectors’ exceptional energy conversion and storage outputs have piqued curiosity in the field of energy research. The current review study focuses on solar thermal application advancements and provides an overview of thermal energy storage devices and solar collectors. This paper presents and discusses a variety of solar collectors, both concentrating and non-concentrating. The energy storage media utilized in these plants, phase change material with melting temperatures exceeding 300°C, was exam-ined. The goal of this study is to provide the necessary information for advanced investiga-tions in the development of cost-effective high-temperature thermal storage systems. Finally, a summary of the presentation, as well as potential solar power plants are reviewed.","PeriodicalId":45841,"journal":{"name":"Journal of Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135944355","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 : 2023-10-17DOI: 10.18186/thermal.1370699
Yunis KHAN, Radhey Shyam MISHRA, Roshan RAMAN, Abdul Wahab HASHMI
In this study, the performance of the organic Rankine cycle combined with the partial cooling supercritical CO2 cycle as the bottoming cycle for recovering the low grade heat powered by a solar power tower was evaluated. Ecofriendly fluids were taken into consideration. To simulate the model under consideration, a computer programme was created in engineering equation solver software. The impacts of solar radiation, concentration ratio, solar incidence angle, CO2 turbine inlet temperature, heat exchanger effectiveness and main compressor inlet tempera-ture were investigated. Based on working fluid R1224yd(Z), it was determined that the com-bined cycle’s thermal efficiency, exergy efficiency, and power output improved from 35.16% to 55.43%, 37.73% to 59.42%, and 188 kW to 298.5 kW, respectively, as solar irradiation raised from 0.4 kW/m2 to 0.95 kW/m2. Lower the solar incidence angle and higher the concentration ratio can enhance the combined system’s performance. Amongst the working fluids that were taken into account, R1224yd(Z) was suggested as having superior performance.
{"title":"Parametric evaluation of solar integrated combined partial cooling supercritical CO2 cycle and Organic Rankine Cycle using low global warming potential fluids","authors":"Yunis KHAN, Radhey Shyam MISHRA, Roshan RAMAN, Abdul Wahab HASHMI","doi":"10.18186/thermal.1370699","DOIUrl":"https://doi.org/10.18186/thermal.1370699","url":null,"abstract":"In this study, the performance of the organic Rankine cycle combined with the partial cooling supercritical CO2 cycle as the bottoming cycle for recovering the low grade heat powered by a solar power tower was evaluated. Ecofriendly fluids were taken into consideration. To simulate the model under consideration, a computer programme was created in engineering equation solver software. The impacts of solar radiation, concentration ratio, solar incidence angle, CO2 turbine inlet temperature, heat exchanger effectiveness and main compressor inlet tempera-ture were investigated. Based on working fluid R1224yd(Z), it was determined that the com-bined cycle’s thermal efficiency, exergy efficiency, and power output improved from 35.16% to 55.43%, 37.73% to 59.42%, and 188 kW to 298.5 kW, respectively, as solar irradiation raised from 0.4 kW/m2 to 0.95 kW/m2. Lower the solar incidence angle and higher the concentration ratio can enhance the combined system’s performance. Amongst the working fluids that were taken into account, R1224yd(Z) was suggested as having superior performance.","PeriodicalId":45841,"journal":{"name":"Journal of Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135944814","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 : 2023-10-17DOI: 10.18186/thermal.1374673
R. YUVARAJ, D. SENTHILKUMAR
Heat transfer models for condensation on hydrophobic and superhydrophobic interfaces are broadly available based on thermal resistance correlations. In the previous studies, very few models are presented based on the scaling factor or Nusselt number, and no model is available that directly correlates Biot number. This study develops a heat transfer model for dropwise condensation underneath a horizontal surface. The present model correlates with the Biot number to predict the heat transfer, temperature variation at the interfaces, solid-liquid, and liquid-vapor, and the growth rate of droplet condensate on the hydrophobic and superhydro-phobic interfaces by using Archimedes’ hat-box theorem. The present model is validated with analytical and experimental results against hydrophobic and superhydrophobic contact angles of similar working parameters made excellent agreements. The analytical model for dropwise condensation produces inaccurate results due to discrepancies and discontinuities due to mul-tiple correlations in the modeling. The present model is modified to obtain a continuous result using experimental data. The modified model is used for analyzing heat transfer by varying Biot numbers from 0.0001 to 1000 using Python 3.6.1 with an accuracy of 10-4. Simulation of the present model results in constant heat transfer at Bi = 4, irrespective of the contact angle. A negligible amount of coating resistance and interface resistance when Bi > 0.1, curvature effect when Bi > 0.04, droplet resistance when Bi < 0.02, the maximum liquid-vapor interface tem-perature at Bi ≈ 10, and maximum solid-liquid interface temperature at Bi ≈ 5, are presented.
基于热阻相关性的疏水和超疏水界面冷凝传热模型广泛可用。在以往的研究中，基于比例因子或Nusselt数的模型很少，也没有与Biot数直接相关的模型。本研究建立了水平面下水滴凝结的传热模型。该模型利用阿基米德帽盒定理与Biot数相关联，预测了疏水和超疏水界面上的传热、界面温度变化、固液界面和汽液界面以及液滴凝结水的生长速率。用分析和实验结果对模型进行了验证，对疏水和超疏水接触角的相似工作参数进行了很好的验证。由于建模过程中多重相关的差异和不连续性，水滴状冷凝的解析模型产生了不准确的结果。利用实验数据对模型进行了修正，得到了连续的结果。利用Python 3.6.1对Biot值在0.0001 ~ 1000范围内变化的传热模型进行了分析，精度为10-4。本模型的模拟结果表明，在Bi = 4时，无论接触角如何，传热都是恒定的。当Bi >0.1, Bi >时的曲率效应;0.04, Bi <时液滴阻力;得到了Bi≈10时的最大液-汽界面温度为0.02,Bi≈5时的最大固-液界面温度为0.02。
{"title":"Heat transfer model for dropwise condensation on hydrophobic and superhydrophobic interfaces","authors":"R. YUVARAJ, D. SENTHILKUMAR","doi":"10.18186/thermal.1374673","DOIUrl":"https://doi.org/10.18186/thermal.1374673","url":null,"abstract":"Heat transfer models for condensation on hydrophobic and superhydrophobic interfaces are broadly available based on thermal resistance correlations. In the previous studies, very few models are presented based on the scaling factor or Nusselt number, and no model is available that directly correlates Biot number. This study develops a heat transfer model for dropwise condensation underneath a horizontal surface. The present model correlates with the Biot number to predict the heat transfer, temperature variation at the interfaces, solid-liquid, and liquid-vapor, and the growth rate of droplet condensate on the hydrophobic and superhydro-phobic interfaces by using Archimedes’ hat-box theorem. The present model is validated with analytical and experimental results against hydrophobic and superhydrophobic contact angles of similar working parameters made excellent agreements. The analytical model for dropwise condensation produces inaccurate results due to discrepancies and discontinuities due to mul-tiple correlations in the modeling. The present model is modified to obtain a continuous result using experimental data. The modified model is used for analyzing heat transfer by varying Biot numbers from 0.0001 to 1000 using Python 3.6.1 with an accuracy of 10-4. Simulation of the present model results in constant heat transfer at Bi = 4, irrespective of the contact angle. A negligible amount of coating resistance and interface resistance when Bi > 0.1, curvature effect when Bi > 0.04, droplet resistance when Bi < 0.02, the maximum liquid-vapor interface tem-perature at Bi ≈ 10, and maximum solid-liquid interface temperature at Bi ≈ 5, are presented.","PeriodicalId":45841,"journal":{"name":"Journal of Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135945149","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}
This research gives an experimental investigation of the scroll compressor, with an emphasis on the effect of leakage on performance enhancement. The effect of gas leakage losses on com-pressor performance is studied both experimentally and conceptually. In the present study, we have modified the scroll compressor to bypass the refrigerant through an orifice called leakage and experimentally investigate the effect of valve opening area and angle to observe the effect of leak gas on compressor performance, compressor capacity loss, discharge line temperature rise, and discharge gas temperature. Experimental results indicated that the maximum per-centage rise in suction superheat is observed to be 7.13% at a maximum effective valve open-ing area of 0.33 m2, whereas the rise in discharge line temperature lies in the range of 0.8% to 2.75% over the entire range of effective leak area. In addition, based on experimentation the 8.9 % maximum compressor capacity loss is observed.
{"title":"Experimental evaluation of the effect of leakage in scroll compressor","authors":"Niyaj Dilavar SHIKALGAR, Shivalingappa Nagappa SAPALI","doi":"10.18186/thermal.1372348","DOIUrl":"https://doi.org/10.18186/thermal.1372348","url":null,"abstract":"This research gives an experimental investigation of the scroll compressor, with an emphasis on the effect of leakage on performance enhancement. The effect of gas leakage losses on com-pressor performance is studied both experimentally and conceptually. In the present study, we have modified the scroll compressor to bypass the refrigerant through an orifice called leakage and experimentally investigate the effect of valve opening area and angle to observe the effect of leak gas on compressor performance, compressor capacity loss, discharge line temperature rise, and discharge gas temperature. Experimental results indicated that the maximum per-centage rise in suction superheat is observed to be 7.13% at a maximum effective valve open-ing area of 0.33 m2, whereas the rise in discharge line temperature lies in the range of 0.8% to 2.75% over the entire range of effective leak area. In addition, based on experimentation the 8.9 % maximum compressor capacity loss is observed.","PeriodicalId":45841,"journal":{"name":"Journal of Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135944146","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 : 2023-10-17DOI: 10.18186/thermal.1376850
Rajendra PRASAD K S, Vijay KRISHNA, Sachin BHARADWAJ
Drastic variation in the thermodynamic properties of supercritical fluids near the pseudo critical point hinders the use of commercial computational fluid dynamics (CFD) software. However, with the increase in computational abilities, along with the use of Artificial Neu-ral Networks (ANN), turbulence heat transfer characteristics of supercritical fluids can be very accurately predicted. In the present work, heat transfer characteristics for a vertically downward flow of carbon dioxide in a pipe are studied for a wide range of heat flux and mass flux values. Firstly, six different turbulent models available in the commercial CFD software - Ansys Fluent are validated against the experimental results. The k- ω Standard model with enhanced wall treatment is found to be the best-suited turbulence model. When experimental results were validated in CFD, an average error of 1% in the bulk fluid temperature and 2% in the wall temperature were recorded. Further, K- ω Standard Turbulence Model is used in CFD for parametric analysis to generate the data for ANN studies. Mass flux range of 238 to 1038 kg/m2s, and heat flux range of 26 kW/m2 to 250 kW/m2 are used to generate 81,432 data sam-ples. These samples were fed into the ANN program to develop an equation that can predict the heat transfer coefficient. It was found that ANN can predict the heat transfer coefficient for the considered range of values within the absolute average relative deviation of 2.183 %.
{"title":"Effect of heat flux and mass flux on the heat transfer characteristics of supercritical carbon dioxide for a vertically downward flow using computational fluid dynamics and artificial neural networks","authors":"Rajendra PRASAD K S, Vijay KRISHNA, Sachin BHARADWAJ","doi":"10.18186/thermal.1376850","DOIUrl":"https://doi.org/10.18186/thermal.1376850","url":null,"abstract":"Drastic variation in the thermodynamic properties of supercritical fluids near the pseudo critical point hinders the use of commercial computational fluid dynamics (CFD) software. However, with the increase in computational abilities, along with the use of Artificial Neu-ral Networks (ANN), turbulence heat transfer characteristics of supercritical fluids can be very accurately predicted. In the present work, heat transfer characteristics for a vertically downward flow of carbon dioxide in a pipe are studied for a wide range of heat flux and mass flux values. Firstly, six different turbulent models available in the commercial CFD software - Ansys Fluent are validated against the experimental results. The k- ω Standard model with enhanced wall treatment is found to be the best-suited turbulence model. When experimental results were validated in CFD, an average error of 1% in the bulk fluid temperature and 2% in the wall temperature were recorded. Further, K- ω Standard Turbulence Model is used in CFD for parametric analysis to generate the data for ANN studies. Mass flux range of 238 to 1038 kg/m2s, and heat flux range of 26 kW/m2 to 250 kW/m2 are used to generate 81,432 data sam-ples. These samples were fed into the ANN program to develop an equation that can predict the heat transfer coefficient. It was found that ANN can predict the heat transfer coefficient for the considered range of values within the absolute average relative deviation of 2.183 %.","PeriodicalId":45841,"journal":{"name":"Journal of Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135944496","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 : 2023-10-17DOI: 10.18186/thermal.1377230
Udayvir SINGH, Harshit PANDEY, Naveen Kumar GUPTA
The current study reviews the research on nanosuspension-enhanced heat pipe technologies. The reviewed studies are categorized based on the nanosuspension type incorporated in the heat pipe i.e., mono & hybrid. The study attempts to identify the heat transport modes in heat pipes and explore their dominance among each other. The dominance of the identified mech-anisms was found to be a strong function of the heat pipe type investigated and get signifi-cantly influenced by the operating conditions. The current review paper will aid in properly understanding the thermal mechanisms prevalent in heat pipes filled with nanosuspensions and to further optimizing their thermal response.
{"title":"An exploratory review on heat transfer mechanisms in nanofluid based heat pipes","authors":"Udayvir SINGH, Harshit PANDEY, Naveen Kumar GUPTA","doi":"10.18186/thermal.1377230","DOIUrl":"https://doi.org/10.18186/thermal.1377230","url":null,"abstract":"The current study reviews the research on nanosuspension-enhanced heat pipe technologies. The reviewed studies are categorized based on the nanosuspension type incorporated in the heat pipe i.e., mono & hybrid. The study attempts to identify the heat transport modes in heat pipes and explore their dominance among each other. The dominance of the identified mech-anisms was found to be a strong function of the heat pipe type investigated and get signifi-cantly influenced by the operating conditions. The current review paper will aid in properly understanding the thermal mechanisms prevalent in heat pipes filled with nanosuspensions and to further optimizing their thermal response.","PeriodicalId":45841,"journal":{"name":"Journal of Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135944357","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 : 2023-10-17DOI: 10.18186/thermal.1376802
Seyyed Alireza MOSTAFAVI, Hamed SAFIKHANI, Hasan KÖTEN, Yasin KARAGOZ
In the World, in many of the large and industrial cities air quality is in a dire situation, and air pollution is considered a major problem. The first step in reducing the level of pollutants is to acquire enough detailed information about these pollutants, including the type, amount, and the rate of annual occurrence. In this study, the data obtained from the existing air quality measuring stations throughout the city of Arak in Iran have been used to conduct an accurate investigation and to perform hourly, daily, monthly, and annual analyses of various pollutants. The hourly analysis of the data collected from the Shariati square station at the downstream of the prevailing wind, which include the collective pollutions of the refinery, petrochemical plant, thermal power plant and the pollution generated by the vehicles in a high-traffic area, with regards to the annual calendar and the variation of pollutants during official holidays, indicates the determining share of vehicles in the air pollution of the city of Arak. Considering the effective role of vehicles in the extensive air pollution of this city, some policies have been suggested for reducing the level of air pollution. As a result of this study, using the stated transportation model the level of pollution in this city is considered to reduce, correcting the city streets and routes from engineering per-spective. Also, results showed that the role of industry and vehicles on the air pollution and the pollution points in Arak city in ratio. The levels of all the pollutants like CO, NOx, PM2.5, O3 and SO2 measured by a station at the downstream and resulted about 3ppm, 20ppb, 10, 40ppb and 4 as a ratio respectively. Lastly, result of model was reported at the end of this paper in term of the optimization of the Arak city residential area.
{"title":"Experimental investigation for the decisive role of vehicles in the air pollution of arak city in Iran and presenting the related solutions to reduce the air pollution","authors":"Seyyed Alireza MOSTAFAVI, Hamed SAFIKHANI, Hasan KÖTEN, Yasin KARAGOZ","doi":"10.18186/thermal.1376802","DOIUrl":"https://doi.org/10.18186/thermal.1376802","url":null,"abstract":"In the World, in many of the large and industrial cities air quality is in a dire situation, and air pollution is considered a major problem. The first step in reducing the level of pollutants is to acquire enough detailed information about these pollutants, including the type, amount, and the rate of annual occurrence. In this study, the data obtained from the existing air quality measuring stations throughout the city of Arak in Iran have been used to conduct an accurate investigation and to perform hourly, daily, monthly, and annual analyses of various pollutants. The hourly analysis of the data collected from the Shariati square station at the downstream of the prevailing wind, which include the collective pollutions of the refinery, petrochemical plant, thermal power plant and the pollution generated by the vehicles in a high-traffic area, with regards to the annual calendar and the variation of pollutants during official holidays, indicates the determining share of vehicles in the air pollution of the city of Arak. Considering the effective role of vehicles in the extensive air pollution of this city, some policies have been suggested for reducing the level of air pollution. As a result of this study, using the stated transportation model the level of pollution in this city is considered to reduce, correcting the city streets and routes from engineering per-spective. Also, results showed that the role of industry and vehicles on the air pollution and the pollution points in Arak city in ratio. The levels of all the pollutants like CO, NOx, PM2.5, O3 and SO2 measured by a station at the downstream and resulted about 3ppm, 20ppb, 10, 40ppb and 4 as a ratio respectively. Lastly, result of model was reported at the end of this paper in term of the optimization of the Arak city residential area.","PeriodicalId":45841,"journal":{"name":"Journal of Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135944498","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 : 2023-10-17DOI: 10.18186/thermal.1374686
Ernest C. NWOSU, Kelechi NSOFOR, Godswill N. NWAJI, Chibuike ONONOGBO, Ikechi OFONG
In this work, an experiment-based study of a double-effect, single-slope active solar still (SSASS) is presented. The system comprises an upper and a lower basin incorporated with a paraffin wax acting as a phase change material (PCM). The use of phase change materials is very important due to their high storage density and the isothermal nature of the storage pro-cess. Paraffin wax was selected based on its attractive thermo-physical properties. The thermal behaviours of the system during the diurnal and nocturnal phases in both compartments were explored. Experimental results showed that the upper basin’s yield contributed more to the overall distillate production over a 24-hour cycle while that of the lower basin predominated the diurnal production. Though the PCM served as an energy source during the nocturnal phase, it did not translate to significant improvement in the yield of the lower basin. The heat retention ability of the lower glazing retarded the condensation of the humid air in the lower compartment during the off-sunshine period. Thus, the nocturnal yield of the system was largely driven by the improved temperature difference between the upper saline water and the upper glazing, as well as the stored thermal energy in the saline water mass before sunset. The system achieved a maximum yield of 2,450 ml/day and a yield rate of 232.5 ml/h. A maximum monthly average yield of 1,787 ml/day was realized in May and a minimum of 692 ml/day in July. Nocturnal distillate production accounted for an average of 55% of the total distillate recovered from the still daily. The system achieved an efficiency range of 12.20 - 32.21%. The cost of freshwater production from the system is estimated at 0.0508 $/L with a payback period of 267 days. Thus, this system is economically viable and suitable particularly, for low-income earners.
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