Pub Date : 2024-10-01DOI: 10.1016/j.ecmx.2024.100733
Valerio Mariani , Saverio Ottaviano , Davide Scampamorte , Andrea De Pascale , Giulio Cazzoli , Lisa Branchini , Gian Marco Bianchi
This study presents a new design tool for working fluid mixtures in organic Rankine cycles. The proposed tool comprises a blend model for the thermophysical properties of the formulated mixtures, an ORC model to predict the performance of the mixtures in a specific application, and an optimizer based on the Bayesian inference method to identify the optimal mixtures compositions to be assessed. The tool is programmed to optimize an objective function based on predefined optimization targets. Importantly, the targets and their respective weights within the objective function can be adjusted to meet the specific requirements of the application under analysis, making this approach adaptable to diverse research and industrial objectives. The algorithm is applied to a case study to demonstrate its ability to define a low-GWP blend that can replace HFC-134a in a micro-scale ORC with recuperator, while maintaining and potentially enhancing performance. The optimization targets specified for the case study are the net power output, the net efficiency, the GWP and the blend size. Power and efficiency are computed through a validated model of the low-temperature ORC system used as benchmark case. The results showed that the procedure was able to formulate several blends that comply with the targets of the assigned task. Amongst the high-scoring mixtures, the most used pure fluids are R32, R152a, R1234yf, and R1234ze(E). The presence of HCs is limited to fewer mixtures, playing the main role of GWP-limiter. A method to estimate the flammability classification of the blends has been also applied, obtaining that most of them belong to the ASHRAE class 2l, except when an HC is present, in which case the fluid is may result in class 3.
{"title":"Optimal mixture design for organic Rankine cycle using machine learning algorithm","authors":"Valerio Mariani , Saverio Ottaviano , Davide Scampamorte , Andrea De Pascale , Giulio Cazzoli , Lisa Branchini , Gian Marco Bianchi","doi":"10.1016/j.ecmx.2024.100733","DOIUrl":"10.1016/j.ecmx.2024.100733","url":null,"abstract":"<div><div>This study presents a new design tool for working fluid mixtures in organic Rankine cycles. The proposed tool comprises a blend model for the thermophysical properties of the formulated mixtures, an ORC model<!--> <!-->to predict the performance of the mixtures in a specific application, and an optimizer based on the Bayesian inference method to identify the optimal mixtures compositions to be assessed. The tool is programmed to optimize an objective function based on predefined optimization targets. Importantly, the targets and their respective weights within the objective function can be adjusted to meet the specific requirements of the application under analysis, making this approach adaptable to diverse research and industrial objectives. The algorithm is applied to a case study to demonstrate its ability to define a low-GWP blend that can replace HFC-134a in a micro-scale ORC with recuperator, while maintaining and potentially enhancing performance. The optimization targets specified for the case study are the net power output, the net efficiency, the GWP and the blend size. Power and efficiency are computed through a validated model of the low-temperature ORC system used as benchmark case. The results showed that the procedure was able to formulate several blends that comply with the targets of the assigned task. Amongst the high-scoring mixtures, the most used pure fluids are R32, R152a, R1234yf, and R1234ze(E). The presence of HCs is limited to fewer mixtures, playing the main role of GWP-limiter. A method to estimate the flammability classification of the blends has been also applied, obtaining that most of them belong to the ASHRAE class 2l, except when an HC is present, in which case the fluid is may result in class 3.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"24 ","pages":"Article 100733"},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, performance evaluation, drying kinetics modelling and economic analysis of locally manufactured rice husk-fueled mixed-flow rice dryer were investigated. The dryer had a size of 0.4 × 0.4 × 0.64 m (width, length, and height) with a holding capacity of 30 kg in a batch. The drying air used had a volume flow rate of 0.06 m3/s, with an average drying air velocity of 0.62 m/s within the drying section. The average temperature recorded during the experiment was 49.5 ± 3.1℃ at the dryer inlet, while the ambient air temperature was 26.4 ± 0.2℃. The dryer was able to reduce the moisture content of the sample rice from 20.9 % (wet bases) to 12 % (wet bases) in 3 h and 10 min, achieving an average drying rate of 0.076 kg water per minute or 0.016 kg water per kg dry matter per minute. In order to achieve this drying rate, the average energy consumption was 37.9 MJ with an average of 54.29 % dryer efficiency. The Modified Henderson & Pabis was the best drying model to predict the drying kinetics in this study among the different thin-layer drying models. The milling quality of the dry product was assessed using the Head Rice Yield (HRY). The HRY was found to be 57.4 ± 0.62 % for long and slender Nerica-4 rice cultivars, the result was above the required customer requirement which is 55 % and more. Furthermore, the economic analysis indicated that the payback period for the developed rice husk-fueled mixed-flow dryer for drying rice was 1.4 years. The dryer, which costs 64,213ETB (approximately USD 1,230) has the potential to significantly reduce postharvest loss and enhance food security and income of smallholder farmers in rural off-grid areas.
{"title":"Modeling the drying kinetics, performance evaluation, and economic analysis of rice drying using a rice husk-fueled mixed-flow dryer","authors":"Yabebal Chekole Mihret , Solomon Tekeste Hailemesikel , Aschale Getnet Alemu , Mulugeta Admasu Delele","doi":"10.1016/j.ecmx.2024.100774","DOIUrl":"10.1016/j.ecmx.2024.100774","url":null,"abstract":"<div><div>In this study, performance evaluation, drying kinetics modelling and economic analysis of locally manufactured rice husk-fueled mixed-flow rice dryer were investigated. The dryer had a size of 0.4 × 0.4 × 0.64 m (width, length, and height) with a holding capacity of 30 kg in a batch. The drying air used had a volume flow rate of 0.06 m<sup>3</sup>/s, with an average drying air velocity of 0.62 m/s within the drying section. The average temperature recorded during the experiment was 49.5 ± 3.1℃ at the dryer inlet, while the ambient air temperature was 26.4 ± 0.2℃. The dryer was able to reduce the moisture content of the sample rice from 20.9 % (wet bases) to 12 % (wet bases) in 3 h and 10 min, achieving an average drying rate of 0.076 kg water per minute or 0.016 kg water per kg dry matter per minute. In order to achieve this drying rate, the average energy consumption was 37.9 MJ with an average of 54.29 % dryer efficiency. The Modified Henderson & Pabis was the best drying model to predict the drying kinetics in this study among the different thin-layer drying models. The milling quality of the dry product was assessed using the Head Rice Yield (HRY). The HRY was found to be 57.4 ± 0.62 % for long and slender Nerica-4 rice cultivars, the result was above the required customer requirement which is 55 % and more. Furthermore, the economic analysis indicated that the payback period for the developed rice husk-fueled mixed-flow dryer for drying rice was 1.4 years. The dryer, which costs 64,213ETB (approximately USD 1,230) has the potential to significantly reduce postharvest loss and enhance food security and income of smallholder farmers in rural off-grid areas.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"24 ","pages":"Article 100774"},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.ecmx.2024.100760
István Lázár , István Hadnagy , Boglárka Bertalan-Balázs , László Bertalan , Sándor Szegedi
Exact knowledge of wind energy potential is a fundamental issue in wind energy utilization. The vertical changes in wind speeds, that is, the wind profile, have a predominant impact on the wind energy available at a location because the kinetic energy of moving air is proportional to the square of the wind speed. Roughness describes the resistance of a 3D surface to moving air. The exponent α of the power law of Hellmann and the roughness length (z0) are two parameters that describe the effects of the roughness of the surface on the wind profile. They can be used for the vertical extrapolation of wind speeds. The exponent α can be determined using multiple height level wind speed measurement data, whereas a reliable technique for the calculation of the roughness length requires detailed knowledge of the 3D geometry of the measurement site. In the present study, the exponent α was calculated based on SODAR wind speed measurements, while (z0) was determined using a combination of GIS and UAS-based aerial survey methods. Wind speeds measured at 50 m were extrapolated for height levels of 80, 90, 100, 110, and 120 m using dynamic power law exponent values. Wind power was determined using the power law (method V1), roughness length (method V2), frequency distribution (method W-RF), and gamma distribution (method W-G), and Windographer software was compared to the values calculated from the empirical (measured) wind speeds. A comparative statistical analysis of the datasets of the power law and roughness length methods on monthly/diurnal, annual/diurnal, and month/direction contexts showed no significant differences at all height levels. Differences can be detected in the distribution of the signs of the differences at heights of 80 and 120 m for the entire dataset. Underestimation was dominant with a significant frequency (over 70 %) in the case of both methods and heights. There were no significant differences between the wind power estimations provided by the different methods, and all the methods involved in the study underestimated the wind speeds and wind energy potential for each height level. Methods V1 and V2 can be used alternatively, depending on the input data available for analysis. The major advantage of method V2 is that it provides the same accuracy as V1, which requires a UAS-based aerial survey at the beginning, but continuous wind measurements must be performed at a lower height only. This means that there is no need for a high measurement tower, which makes the measurements simpler, more cost-effective, and causes much less disturbance to the environment. Another important advantage of the methods presented here is that they use a dynamic approach of power law exponent values that provide a more realistic estimation of wind speed and energy on a diurnal scale.
{"title":"Comparative examinations of wind speed and energy extrapolation methods using remotely sensed data – A case study from Hungary","authors":"István Lázár , István Hadnagy , Boglárka Bertalan-Balázs , László Bertalan , Sándor Szegedi","doi":"10.1016/j.ecmx.2024.100760","DOIUrl":"10.1016/j.ecmx.2024.100760","url":null,"abstract":"<div><div>Exact knowledge of wind energy potential is a fundamental issue in wind energy utilization. The vertical changes in wind speeds, that is, the wind profile, have a predominant impact on the wind energy available at a location because the kinetic energy of moving air is proportional to the square of the wind speed. Roughness describes the resistance of a 3D surface to moving air. The exponent α of the power law of Hellmann and the roughness length (z<sub>0</sub>) are two parameters that describe the effects of the roughness of the surface on the wind profile. They can be used for the vertical extrapolation of wind speeds. The exponent α can be determined using multiple height level wind speed measurement data, whereas a reliable technique for the calculation of the roughness length requires detailed knowledge of the 3D geometry of the measurement site. In the present study, the exponent α was calculated based on SODAR wind speed measurements, while (z<sub>0</sub>) was determined using a combination of GIS and UAS-based aerial survey methods. Wind speeds measured at 50 m were extrapolated for height levels of 80, 90, 100, 110, and 120 m using dynamic power law exponent values. Wind power was determined using the power law (method V1), roughness length (method V2), frequency distribution (method W-RF), and gamma distribution (method W-G), and Windographer software was compared to the values calculated from the empirical (measured) wind speeds. A comparative statistical analysis of the datasets of the power law and roughness length methods on monthly/diurnal, annual/diurnal, and month/direction contexts showed no significant differences at all height levels. Differences can be detected in the distribution of the signs of the differences at heights of 80 and 120 m for the entire dataset. Underestimation was dominant with a significant frequency (over 70 %) in the case of both methods and heights. There were no significant differences between the wind power estimations provided by the different methods, and all the methods involved in the study underestimated the wind speeds and wind energy potential for each height level. Methods V1 and V2 can be used alternatively, depending on the input data available for analysis. The major advantage of method V2 is that it provides the same accuracy as V1, which requires a UAS-based aerial survey at the beginning, but continuous wind measurements must be performed at a lower height only. This means that there is no need for a high measurement tower, which makes the measurements simpler, more cost-effective, and causes much less disturbance to the environment. Another important advantage of the methods presented here is that they use a dynamic approach of power law exponent values that provide a more realistic estimation of wind speed and energy on a diurnal scale.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"24 ","pages":"Article 100760"},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142539952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.ecmx.2024.100800
Karen Quintana , Andrés A. García Blanco , Lucile Bernadet , Daniel Ruiz , Marc Torrell , Jordi Guilera
Power-to-Liquid processes have the potential to decarbonize maritime transport by producing carbon–neutral electro-fuels. One example of a potential implementation of this process is the combined technology of co-electrolysis of carbon dioxide and water, along with Fischer–Tropsch Synthesis. Given the promising prospects of producing electro-fuels to achieve net-zero objectives by 2050, a critical question that arises is whether sufficient resources are available to replace the current demand for fossil marine gas oil (MGO). This study evaluates the requirements and availability of resources necessary for producing marine electro-fuel using the MGO demand at the Port of Barcelona as a case study. The results indicate that current supplies of renewable energy and biogenic CO2 are insufficient to fully replace the total fossil MGO demand. However, by 2050, it is expected that these resource limitations will be overcome, considering the current official projections for the growth of renewable electricity and the biogas industry. The deployment of renewable electricity generation and the rollout of biomethane industrial network as biogenic carbon source is found to be essential for the viability of the future substitution of fossil MGO with its electro-fuel equivalent.
{"title":"Resource availability for e-MGO adoption in maritime transport: A case study in the Port of Barcelona","authors":"Karen Quintana , Andrés A. García Blanco , Lucile Bernadet , Daniel Ruiz , Marc Torrell , Jordi Guilera","doi":"10.1016/j.ecmx.2024.100800","DOIUrl":"10.1016/j.ecmx.2024.100800","url":null,"abstract":"<div><div>Power-to-Liquid processes have the potential to decarbonize maritime transport by producing carbon–neutral electro-fuels. One example of a potential implementation of this process is the combined technology of co-electrolysis of carbon dioxide and water, along with Fischer–Tropsch Synthesis. Given the promising prospects of producing electro-fuels to achieve net-zero objectives by 2050, a critical question that arises is whether sufficient resources are available to replace the current demand for fossil marine gas oil (MGO). This study evaluates the requirements and availability of resources necessary for producing marine electro-fuel using the MGO demand at the Port of Barcelona as a case study. The results indicate that current supplies of renewable energy and biogenic CO<sub>2</sub> are insufficient to fully replace the total fossil MGO demand. However, by 2050, it is expected that these resource limitations will be overcome, considering the current official projections for the growth of renewable electricity and the biogas industry. The deployment of renewable electricity generation and the rollout of biomethane industrial network as biogenic carbon source is found to be essential for the viability of the future substitution of fossil MGO with its electro-fuel equivalent.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"24 ","pages":"Article 100800"},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142704501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Self-starting torque () presents a significant challenge for Darrieus vertical axis wind turbines (DVAWTs), often necessitating external assistance to initiate rotation. This study addresses the issue by optimizing airfoil design, employing embossed blades (EBs), and adjusting blade height (H) to reduce . From an analysis of 43 rotors at a chord-based Reynolds number () of 45,192, national advisory committee for aeronautics (NACA) 0015, NACA4412, and NACA4415 rotors were selected for their superior power coefficients (). These rotors were optimized using double-multiple streamtube theory (DMST) and particle swarm optimization (PSO), focusing on the thickness-to-chord ratio (TCR). Among them, the NACA0015-Opt rotor achieved the highest , demonstrating its effectiveness in enhancing DVAWT efficiency. This study also investigates the effect of H on the performance of EBs, comparing H of 35 cm and 75 cm. Experimental findings reveal that combining airfoil optimization with EBs, along with an increased H, leads to a substantial decrease in . Specifically, higher H enhance the aerodynamic performance of EBs by improving airflow over the blade surface, further reducing drag and contributing to a significant reduction in . At a H of 75 cm, the embossed blade Darrieus vertical axis wind turbine (EB-DVAWT) equipped with the optimized NACA0015-Opt rotor required 15.92 %, 17.04 %, 18.12 %, 21.23 %, 52.06 %, 49.23 %, 51.25 %, 35.20 %, 14.12 %, and 9.09 % less at wind velocities () of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 9.5 m/s, respectively, compared to the baseline smooth blade Darrieus vertical axis wind turbine (SB-DVAWT) with the original NACA0015 rotor.
{"title":"Blade height impact on self-starting torque for Darrieus vertical axis wind turbines","authors":"Hossein Seifi Davari , Ruxandra Mihaela Botez , Mohsen Seify Davari , Harun Chowdhury , Hasan Hosseinzadeh","doi":"10.1016/j.ecmx.2024.100814","DOIUrl":"10.1016/j.ecmx.2024.100814","url":null,"abstract":"<div><div>Self-starting torque (<span><math><msub><mi>T</mi><mrow><mi>Self</mi><mo>-</mo><mi>s</mi><mi>t</mi><mi>a</mi><mi>r</mi><mi>t</mi><mi>i</mi><mi>n</mi><mi>g</mi></mrow></msub></math></span>) presents a significant challenge for Darrieus vertical axis wind turbines (DVAWTs), often necessitating external assistance to initiate rotation. This study addresses the issue by optimizing airfoil design, employing embossed blades (EBs), and adjusting blade height (<em>H</em>) to reduce <span><math><msub><mi>T</mi><mrow><mi>Self</mi><mo>-</mo><mi>s</mi><mi>t</mi><mi>a</mi><mi>r</mi><mi>t</mi><mi>i</mi><mi>n</mi><mi>g</mi></mrow></msub></math></span>. From an analysis of 43 rotors at a chord-based Reynolds number (<span><math><msub><mrow><mi>Re</mi></mrow><mi>c</mi></msub></math></span>) of 45,192, national advisory committee for aeronautics (NACA) 0015, NACA4412, and NACA4415 rotors were selected for their superior power coefficients (<span><math><msub><mi>C</mi><mi>p</mi></msub></math></span>). These rotors were optimized using double-multiple streamtube theory (DMST) and particle swarm optimization (PSO), focusing on the thickness-to-chord ratio (TCR). Among them, the NACA0015-Opt rotor achieved the highest <span><math><msub><mi>C</mi><mi>p</mi></msub></math></span>, demonstrating its effectiveness in enhancing DVAWT efficiency. This study also investigates the effect of <em>H</em> on the performance of EBs, comparing <em>H</em> of 35 cm and 75 cm. Experimental findings reveal that combining airfoil optimization with EBs, along with an increased <em>H</em>, leads to a substantial decrease in <span><math><msub><mi>T</mi><mrow><mi>Self</mi><mo>-</mo><mi>s</mi><mi>t</mi><mi>a</mi><mi>r</mi><mi>t</mi><mi>i</mi><mi>n</mi><mi>g</mi></mrow></msub></math></span>. Specifically, higher <em>H</em> enhance the aerodynamic performance of EBs by improving airflow over the blade surface, further reducing drag and contributing to a significant reduction in <span><math><msub><mi>T</mi><mrow><mi>Self</mi><mo>-</mo><mi>s</mi><mi>t</mi><mi>a</mi><mi>r</mi><mi>t</mi><mi>i</mi><mi>n</mi><mi>g</mi></mrow></msub></math></span>. At a <em>H</em> of 75 cm, the embossed blade Darrieus vertical axis wind turbine (EB-DVAWT) equipped with the optimized NACA0015-Opt rotor required 15.92 %, 17.04 %, 18.12 %, 21.23 %, 52.06 %, 49.23 %, 51.25 %, 35.20 %, 14.12 %, and 9.09 % less <span><math><msub><mi>T</mi><mrow><mi>Self</mi><mo>-</mo><mi>s</mi><mi>t</mi><mi>a</mi><mi>r</mi><mi>t</mi><mi>i</mi><mi>n</mi><mi>g</mi></mrow></msub></math></span> at wind velocities (<span><math><msub><mi>U</mi><mi>∞</mi></msub></math></span>) of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 9.5 m/s, respectively, compared to the baseline smooth blade Darrieus vertical axis wind turbine (SB-DVAWT) with the original NACA0015 rotor.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"24 ","pages":"Article 100814"},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.ecmx.2024.100717
Bairi Levi Rakshith , Lazarus Godson Asirvatham , Appadurai Anitha Angeline , Bryan Lancy , J Perinba Selvin Raj , Jefferson Raja Bose , Somchai Wongwises
Flat heat pipes (FHPs) with rectangular groove wick structures fail to sufficiently uplift the working fluid’s liquid meniscus to cover the upper sides of the groove walls due to the vertically flat wall design. This results in the formation of non-evaporative zones, particularly in the evaporator region, leading to elevated wall temperatures at high heat loads. To address this issue, a novel FHP with elliptical grooves as wick is designed and tested across heat loads ranging from 30 to 360 W. Elliptical groove depths of 0.5 mm and 0.7 mm are evaluated and compared to FHPs with rectangular grooves. Results showed that at 360 W, the 0.7 mm depth elliptical grooves resulted in 6.5 % reduction in evaporator wall temperature and 27.8 % reduction in thermal resistance, along with 31.5 % enhancement in effective thermal conductivity compared to rectangular grooves. The curvature of the elliptical grooves, combined with enhanced surface tension effects of the working fluid, efficiently uplifted the liquid meniscus to cover the upper wall of the groove, minimizing non-evaporative zones. Additionally, FHPs with elliptical grooves demonstrated lower entropy generation, indicating higher thermal efficiency. Consequently, FHPs with elliptical groove designs are concluded to be an efficient and suitable solution for the thermal management of miniaturized electronic devices.
采用矩形槽芯结构的扁平热管 (FHP) 由于采用垂直扁平的管壁设计，工作流体的液体半月板无法充分上浮以覆盖槽壁的上侧。这就形成了非蒸发区，尤其是在蒸发器区域，导致在高热负荷下壁温升高。为了解决这个问题，我们设计了一种新型的全功率变流器，采用椭圆形凹槽作为灯芯，并在 30 到 360 W 的热负荷范围内进行了测试。结果表明，在功率为 360 W 时，与矩形凹槽相比，0.7 mm 深的椭圆形凹槽使蒸发器壁温降低了 6.5%，热阻降低了 27.8%，有效热传导率提高了 31.5%。椭圆形凹槽的弧度与工作流体表面张力效应的增强相结合，有效地将液体半月板提升到凹槽上壁，最大限度地减少了非蒸发区。此外，带有椭圆形凹槽的 FHP 产生的熵值较低，表明热效率较高。因此，采用椭圆形凹槽设计的 FHP 是微型电子设备热管理的一种高效、合适的解决方案。
{"title":"Thermal management performance of a novel elliptically grooved flat heat pipe system embedded with internally cooled condenser","authors":"Bairi Levi Rakshith , Lazarus Godson Asirvatham , Appadurai Anitha Angeline , Bryan Lancy , J Perinba Selvin Raj , Jefferson Raja Bose , Somchai Wongwises","doi":"10.1016/j.ecmx.2024.100717","DOIUrl":"10.1016/j.ecmx.2024.100717","url":null,"abstract":"<div><div>Flat heat pipes (FHPs) with rectangular groove wick structures fail to sufficiently uplift the working fluid’s liquid meniscus to cover the upper sides of the groove walls due to the vertically flat wall design. This results in the formation of non-evaporative zones, particularly in the evaporator region, leading to elevated wall temperatures at high heat loads. To address this issue, a novel FHP with elliptical grooves as wick is designed and tested across heat loads ranging from 30 to 360 W. Elliptical groove depths of 0.5 mm and 0.7 mm are evaluated and compared to FHPs with rectangular grooves. Results showed that at 360 W, the 0.7 mm depth elliptical grooves resulted in 6.5 % reduction in evaporator wall temperature and 27.8 % reduction in thermal resistance, along with 31.5 % enhancement in effective thermal conductivity compared to rectangular grooves. The curvature of the elliptical grooves, combined with enhanced surface tension effects of the working fluid, efficiently uplifted the liquid meniscus to cover the upper wall of the groove, minimizing non-evaporative zones. Additionally, FHPs with elliptical grooves demonstrated lower entropy generation, indicating higher thermal efficiency. Consequently, FHPs with elliptical groove designs are concluded to be an efficient and suitable solution for the thermal management of miniaturized electronic devices.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"24 ","pages":"Article 100717"},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.ecmx.2024.100779
Ghinwa Naeem , Muhammad Asif , Muhammad Khalid
The Fourth Industrial Revolution, driven by Industry 4.0 technologies, is rapidly transforming the Renewable Energy Sector (RES), offering significant benefits across the entire value chain of renewable energy systems. This study contributes to the literature by systematically investigating the role of 13 key Industry 4.0 digital technologies − Smart meters, Smart grids, Artificial Intelligence, Machine Learning, Digital Twin, 3D Printing, Big Data Analytics, Robotics, Sensors, Internet of Things, Cloud computing, Blockchain, and Cyber Security − in terms of their functions, applications, and potential in the RES. It further examines market dynamics, growth trajectories, and policy implications of Industry 4.0 technologies, highlighting the practical applications and challenges encountered in their adoption in RES. Utilizing a mixed-methods approach, which combines a systematic literature review adopting the PRISMA methodology with insights from industry reports and case studies, the study finds that Industry 4.0 technologies play a critical role in enhancing efficiency, cost-effectiveness, and sustainability in areas such as renewable energy systems’ operation, integration, energy production, management, and maintenance. For example, in the case of solar panels, AI-powered systems can optimize energy production and consumption, potentially leading to a 20% increase in efficiency and a 50% reduction in production cost. Furthermore, the study reflects on the challenges faced by the discussed technologies, including interoperability issues, cybersecurity risks, high implementation costs, and potential job displacement. It concludes that addressing these challenges through collaborative efforts and policy interventions is crucial to fully harness the transformative potential of digital technologies in the RES.
{"title":"Industry 4.0 digital technologies for the advancement of renewable energy: Functions, applications, potential and challenges","authors":"Ghinwa Naeem , Muhammad Asif , Muhammad Khalid","doi":"10.1016/j.ecmx.2024.100779","DOIUrl":"10.1016/j.ecmx.2024.100779","url":null,"abstract":"<div><div>The Fourth Industrial Revolution, driven by Industry 4.0 technologies, is rapidly transforming the Renewable Energy Sector (RES), offering significant benefits across the entire value chain of renewable energy systems. This study contributes to the literature by systematically investigating the role of 13 key Industry 4.0 digital technologies − Smart meters, Smart grids, Artificial Intelligence, Machine Learning, Digital Twin, 3D Printing, Big Data Analytics, Robotics, Sensors, Internet of Things, Cloud computing, Blockchain, and Cyber Security − in terms of their functions, applications, and potential in the RES. It further examines market dynamics, growth trajectories, and policy implications of Industry 4.0 technologies, highlighting the practical applications and challenges encountered in their adoption in RES. Utilizing a mixed-methods approach, which combines a systematic literature review adopting the PRISMA methodology with insights from industry reports and case studies, the study finds that Industry 4.0 technologies play a critical role in enhancing efficiency, cost-effectiveness, and sustainability in areas such as renewable energy systems’ operation, integration, energy production, management, and maintenance. For example, in the case of solar panels, AI-powered systems can optimize energy production and consumption, potentially leading to a 20% increase in efficiency and a 50% reduction in production cost. Furthermore, the study reflects on the challenges faced by the discussed technologies, including interoperability issues, cybersecurity risks, high implementation costs, and potential job displacement. It concludes that addressing these challenges through collaborative efforts and policy interventions is crucial to fully harness the transformative potential of digital technologies in the RES.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"24 ","pages":"Article 100779"},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Holistic strategies in energy, water, and environmental systems can enhance climate change mitigation efforts. Recent scientific innovations have opened up numerous pathways toward comprehensive human development. This editorial explores the 18th Conference on Sustainable Development of Energy, Water and Environment Systems (SDEWES), highlighting eight key topics from eight research articles that showcase the latest scientific advancements. The articles that addressed energy saving, energy efficiency, and clean energy, include (1) Bioethanol burner operating parameters optimization: Effects of burner opening area modulation on heat output and flue gas composition, (2) Integration of photovoltaic panels and biomass-fuelled CHP in an Italian renewable energy community, (3) AI-Driven Innovations in Greenhouse Agriculture: Reanalysis of Sustainability and Energy Efficiency Impacts, and (4) Methodology to assess the impact of urban vegetation on the energy consumption of residential buildings. A case study in a Mediterranean city. One article discussed infrastructure planning: (5) Dynamic Reduction of Network Flow Optimization Problem: Case of Waste-to-Energy Infrastructure Planning in Czech Republic. One article reviewed the effects of national policies on renewable energy communities: (6) How do national policies influence energy community development across Europe? A review on societal, technical, and economical factors. Additionally, other two articles discussed the method for projections of wind power: (7) A copula post-processing method for wind power projections under climate change, and comparative analysis on open/closed loop with thermal load in an elastocaloric device: (8) 2D thermo-fluidynamic rotary model of an elastocaloric cooling device: The energy performances.
{"title":"Technologies and strategies fostering the sustainable development of energy, water and environment systems","authors":"Davide Astiaso Garcia , Predrag Raskovic , Neven Duić , Moh’d Ahmad Al-Nimr","doi":"10.1016/j.ecmx.2024.100736","DOIUrl":"10.1016/j.ecmx.2024.100736","url":null,"abstract":"<div><div>Holistic strategies in energy, water, and environmental systems can enhance climate change mitigation efforts. Recent scientific innovations have opened up numerous pathways toward comprehensive human development. This editorial explores the 18th Conference on Sustainable Development of Energy, Water and Environment Systems (SDEWES), highlighting eight key topics from eight research articles that showcase the latest scientific advancements. The articles that addressed energy saving, energy efficiency, and clean energy, include (1) Bioethanol burner operating parameters optimization: Effects of burner opening area modulation on heat output and flue gas composition, (2) Integration of photovoltaic panels and biomass-fuelled CHP in an Italian renewable energy community, (3) AI-Driven Innovations in Greenhouse Agriculture: Reanalysis of Sustainability and Energy Efficiency Impacts, and (4) Methodology to assess the impact of urban vegetation on the energy consumption of residential buildings. A case study in a Mediterranean city. One article discussed infrastructure planning: (5) Dynamic Reduction of Network Flow Optimization Problem: Case of Waste-to-Energy Infrastructure Planning in Czech Republic. One article reviewed the effects of national policies on renewable energy communities: (6) How do national policies influence energy community development across Europe? A review on societal, technical, and economical factors. Additionally, other two articles discussed the method for projections of wind power: (7) A copula post-processing method for wind power projections under climate change, and comparative analysis on open/closed loop with thermal load in an elastocaloric device: (8) 2D thermo-fluidynamic rotary model of an elastocaloric cooling device: The energy performances.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"24 ","pages":"Article 100736"},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.ecmx.2024.100734
Noor Yusuf, Ahmed AlNouss, Roberto Baldacci, Tareq Al-Ansari
Despite the anticipated growth in the global demand for energy commodities, the frequently changing market dynamics imposed by environmental regulations and political sanctions create end-user demand uncertainties. This imposes the need for prompt quantitative decision-making approaches to understand how various market structures affect the planning of current natural gas projects. Agent-based modelling (ABM) emerges as a powerful approach to facilitate expedited and well-informed decisions amidst limited timeframes. This study deploys agent-based modelling to investigate natural gas allocation across various utilisation routes under diverse economic and environmental scenarios. Results from four main cases and two sub-scenarios imply that the allocation strategy is driven by utilisation routes considered in each case, followed by the allocation target (i.e., economic or environmental) and the operational bounds. The results reveal that cases prioritising natural gas monetisation for export outperform those meeting power requirements in average annual profitability. In case 4, considering a full network with power, the average annual profitability in the economic scenario reduces by approximately 47% compared to case 3, representing the optimal network configuration with $5.22 billion in average annual profitability. However, the economic scenario of case 3 demonstrates the second-highest rate of emissions (0.66 CO2-eq t/y), following the hydrogen-rich process routes in case 2. Overall, this study presents an innovative data-driven framework for enhancing strategic resource allocation in dynamic business environments. By integrating empirical evidence and technical data with an advanced technical tool (i.e., ABM), the framework provides decision-makers and policymakers with valuable insights for managing uncertainties and shifts in market structures, particularly in existing natural gas projects.
{"title":"Data-Driven Decision-Making for Flexible Natural Gas Allocation Under Uncertainties: An Agent-Based Modelling Approach","authors":"Noor Yusuf, Ahmed AlNouss, Roberto Baldacci, Tareq Al-Ansari","doi":"10.1016/j.ecmx.2024.100734","DOIUrl":"10.1016/j.ecmx.2024.100734","url":null,"abstract":"<div><div>Despite the anticipated growth in the global demand for energy commodities, the frequently changing market dynamics imposed by environmental regulations and political sanctions create end-user demand uncertainties. This imposes the need for prompt quantitative decision-making approaches to understand how various market structures affect the planning of current natural gas projects. Agent-based modelling (ABM) emerges as a powerful approach to facilitate expedited and well-informed decisions amidst limited timeframes. This study deploys agent-based modelling to investigate natural gas allocation across various utilisation routes under diverse economic and environmental scenarios. Results from four main cases and two sub-scenarios imply that the allocation strategy is driven by utilisation routes considered in each case, followed by the allocation target (i.e., economic or environmental) and the operational bounds. The results reveal that cases prioritising natural gas monetisation for export outperform those meeting power requirements in average annual profitability. In case 4, considering a full network with power, the average annual profitability in the economic scenario reduces by approximately 47% compared to case 3, representing the optimal network configuration with $5.22 billion in average annual profitability. However, the economic scenario of case 3 demonstrates the second-highest rate of emissions (0.66 CO<sub>2</sub>-eq t/y), following the hydrogen-rich process routes in case 2. Overall, this study presents an innovative data-driven framework for enhancing strategic resource allocation in dynamic business environments. By integrating empirical evidence and technical data with an advanced technical tool (i.e., ABM), the framework provides decision-makers and policymakers with valuable insights for managing uncertainties and shifts in market structures, particularly in existing natural gas projects.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"24 ","pages":"Article 100734"},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142437803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.ecmx.2024.100749
R.S.R.M. Hafriz , S.H. Habib , N.A. Raof , M.Y. Ong , C.C. Seah , S.Z. Razali , R. Yunus , N.M. Razali , A. Salmiaton
Green diesel derived from sustainable biomass is an alternative and potential energy source to petroleum fossil fuel replacement in response to reducing carbon footprint and achieving a circular economy, which has sparked public interest and concern in advancing renewable energy development. Catalytic deoxygenation (CDO) is a promising method because it can process a wide variety of feedstocks and produce a diverse range of fuels. The CDO of soybean oil (SO) was executed using a modified low-cost dolomite catalyst denoted as NiO-CD catalyst and its performance has been compared with commercial zeolite heterogeneous-based catalysts such as ZSM-5, HY-zeolite and FCC. The NiO-CD catalyst exhibited exceptional deoxygenation ability, attaining an 88.6 % removal efficiency of oxygenated compounds, markedly surpassing all commercially available zeolite catalysts. The highest degree of CDO of SO via decarboxylation/decarbonylation (deCOx) reaction was achieved due to improvement in particle size, mesoporous structure and the presence of the synergistic effect of modified bi-functional acid-base properties of NiO-CaO/MgO catalyst. To investigate the effect of NiO-CD catalyst loading ranging from 1 to 7 wt%, a One Factor At a Time (OFAT) optimisation study was performed. The current study found that an optimised NiO-CD catalyst loading of 5 wt% yielded the highest green diesel (50.5 wt%) with an 88.63 % hydrocarbon composition. The influence of catalyst loading on deoxygenation activity is significant in green diesel production using NiO-CD catalyst.
{"title":"Soybean oil-based green diesel production via catalytic deoxygenation (CDO) technology using low-cost modified dolomite and commercial zeolite-based catalyst","authors":"R.S.R.M. Hafriz , S.H. Habib , N.A. Raof , M.Y. Ong , C.C. Seah , S.Z. Razali , R. Yunus , N.M. Razali , A. Salmiaton","doi":"10.1016/j.ecmx.2024.100749","DOIUrl":"10.1016/j.ecmx.2024.100749","url":null,"abstract":"<div><div>Green diesel derived from sustainable biomass is an alternative and potential energy source to petroleum fossil fuel replacement in response to reducing carbon footprint and achieving a circular economy, which has sparked public interest and concern in advancing renewable energy development. Catalytic deoxygenation (CDO) is a promising method because it can process a wide variety of feedstocks and produce a diverse range of fuels. The CDO of soybean oil (SO) was executed using a modified low-cost dolomite catalyst denoted as NiO-CD catalyst and its performance has been compared with commercial zeolite heterogeneous-based catalysts such as ZSM-5, HY-zeolite and FCC. The NiO-CD catalyst exhibited exceptional deoxygenation ability, attaining an 88.6 % removal efficiency of oxygenated compounds, markedly surpassing all commercially available zeolite catalysts. The highest degree of CDO of SO via decarboxylation/decarbonylation (deCOx) reaction was achieved due to improvement in particle size, mesoporous structure and the presence of the synergistic effect of modified bi-functional acid-base properties of NiO-CaO/MgO catalyst. To investigate the effect of NiO-CD catalyst loading ranging from 1 to 7 wt%, a One Factor At a Time (OFAT) optimisation study was performed. The current study found that an optimised NiO-CD catalyst loading of 5 wt% yielded the highest green diesel (50.5 wt%) with an 88.63 % hydrocarbon composition. The influence of catalyst loading on deoxygenation activity is significant in green diesel production using NiO-CD catalyst.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"24 ","pages":"Article 100749"},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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