Pub Date : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012099
G. R. Pedrosa, H. L. Ong, A. R. Villagracia
In the current landscape of increasing focus on green technology, hydrogen fuel emerges as a pivotal alternative energy source. While existing technology facilitates hydrogen use in fuel cells, the practicality of this fuel could be significantly enhanced with a more efficient and safer storage approach. Researchers are actively exploring one-dimensional systems as potential hydrogen storage solutions, yielding promising outcomes. A notable study delved into the hydrogen storage capacity and performance of a Ti-decorated carbyne ring using density functional theory calculations. The researchers observed a robust, non-deforming bond between the Ti adatom and the carbyne ring, displaying characteristics akin to ionic bonding. Detailed analyses of electronic properties, including density of states and band structure, highlighted a strong interaction through the alignment of p-orbitals with the Ti atom. Upon the adsorption of H2 onto the decorated carbyne ring, it was noted that the Ti-decorated systems could each adsorb up to six H2 molecules, exhibiting weak physisorption energies within the Van der Waals range. The charge density profile indicated a dipole-dipole interaction, affirming the potential of the material as a viable H2 storage medium. In conclusion, as green technology advances, hydrogen fuel, especially when stored innovatively with materials like the Ti-decorated carbyne ring, emerges as a crucial component in the pursuit of sustainable energy solutions.
当前，人们越来越关注绿色技术，氢燃料成为一种关键的替代能源。虽然现有技术有利于氢在燃料电池中的使用，但如果采用更高效、更安全的储存方法，这种燃料的实用性将大大提高。研究人员正在积极探索一维系统作为潜在的氢储存解决方案，并取得了可喜的成果。一项值得注意的研究利用密度泛函理论计算深入研究了钛装饰碳环的储氢能力和性能。研究人员观察到，钛金刚原子和碳炔环之间形成了稳固的非变形键，显示出类似于离子键的特性。对电子特性（包括状态密度和能带结构）的详细分析突出显示了通过 p 轨道与钛原子的排列产生的强烈相互作用。在装饰的卡宾环上吸附 H2 时，发现每个钛装饰系统最多可吸附六个 H2 分子，在范德华范围内表现出微弱的物理吸附能。电荷密度曲线显示出偶极子-偶极子相互作用，肯定了该材料作为一种可行的 H2 储存介质的潜力。总之，随着绿色技术的发展，氢燃料，尤其是使用钛装饰的碳炔环等创新材料储存氢燃料，已成为追求可持续能源解决方案的关键组成部分。
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Pub Date : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012009
K H Wong, C T J Lim, J. H. Ng, A. Fazlizan, X H Wang
Increasing amounts of study and research on vertical axis wind turbines (VAWTs) have shown that they are a competitive option in wind energy power generation. However, the VAWT’s primary drawback is low power efficiencies. Although there are several studies on the effects of solidity on Darrieus VAWT performances, few focus on the effect of the aerofoil chord length. Hence, in the present study, 2D numerical simulations are performed to explore the effects of different aerofoil chord lengths on the performance of a Darrieus VAWT. The simulation was first validated with the experimental data from the literature. The studied turbine is a 4-bladed VAWT fitted with NACA0021 blades with an original chord length, c of 85.8 mm and another with an increased chord length of 1.2 c (102.96 mm). Additionally, a modified rotor geometry with mixed chord lengths of c and 1.2 c to improve turbine performance is proposed and investigated. The coefficients of power (C P) and torque (C T) for tip speed ratios (TSRs) between 1.4 and 3.3 for each of the turbines are evaluated and comparatively analysed. All the data was obtained using the computational fluid dynamics (CFD) software ANSYS Fluent in conjunction with the shear stress transport (SST) k−ω turbulence model. The findings show that the turbine with 1.2 c chord length and hence larger solidity outperforms those with smaller chord lengths at low TSRs. However, their performances decrease significantly at TSRs above 2.5, resulting in up to 86.1% lower C P values. The mixed chord lengths case was successful at achieving significantly higher C P values at both TSR ranges with only a decrease of 3.03% in maximum C P at its optimum TSR.
对垂直轴风力涡轮机 (VAWT) 越来越多的研究表明，垂直轴风力涡轮机是风能发电中一种具有竞争力的选择。然而，垂直轴风力涡轮机的主要缺点是发电效率低。虽然有一些研究涉及固体对达里厄斯 VAWT 性能的影响，但很少有人关注气膜弦长的影响。因此，本研究进行了二维数值模拟，以探讨不同气膜弦长对达里厄斯 VAWT 性能的影响。模拟结果首先与文献中的实验数据进行了验证。所研究的涡轮机是一个 4 翼 VAWT，配备 NACA0021 叶片，原始弦长 c 为 85.8 毫米，另一个弦长增加了 1.2 c（102.96 毫米）。此外，还提出并研究了弦长为 c 和 1.2 c 混合的改进转子几何形状，以提高涡轮机的性能。对每种涡轮机在 1.4 和 3.3 之间的叶尖转速比 (TSR) 下的功率系数 (C P) 和扭矩系数 (C T) 进行了评估和比较分析。所有数据均使用计算流体动力学（CFD）软件 ANSYS Fluent 和剪应力传输（SST）k-ω 湍流模型获得。研究结果表明，在低 TSR 条件下，弦长为 1.2 c 的涡轮机性能优于弦长较小的涡轮机。然而，当 TSR 超过 2.5 时，它们的性能明显下降，导致 C P 值降低达 86.1%。弦长混合的情况在两个 TSR 范围内都成功地获得了明显较高的 C P 值，在其最佳 TSR 下，最大 C P 值仅降低了 3.03%。
{"title":"Numerical investigation of the effects of increased and mixed chord lengths for a 4-bladed darrieus vertical axis wind turbine","authors":"K H Wong, C T J Lim, J. H. Ng, A. Fazlizan, X H Wang","doi":"10.1088/1755-1315/1372/1/012009","DOIUrl":"https://doi.org/10.1088/1755-1315/1372/1/012009","url":null,"abstract":"\u0000 Increasing amounts of study and research on vertical axis wind turbines (VAWTs) have shown that they are a competitive option in wind energy power generation. However, the VAWT’s primary drawback is low power efficiencies. Although there are several studies on the effects of solidity on Darrieus VAWT performances, few focus on the effect of the aerofoil chord length. Hence, in the present study, 2D numerical simulations are performed to explore the effects of different aerofoil chord lengths on the performance of a Darrieus VAWT. The simulation was first validated with the experimental data from the literature. The studied turbine is a 4-bladed VAWT fitted with NACA0021 blades with an original chord length, c of 85.8 mm and another with an increased chord length of 1.2 c (102.96 mm). Additionally, a modified rotor geometry with mixed chord lengths of c and 1.2 c to improve turbine performance is proposed and investigated. The coefficients of power (C\u0000 P) and torque (C\u0000 T) for tip speed ratios (TSRs) between 1.4 and 3.3 for each of the turbines are evaluated and comparatively analysed. All the data was obtained using the computational fluid dynamics (CFD) software ANSYS Fluent in conjunction with the shear stress transport (SST) k−ω turbulence model. The findings show that the turbine with 1.2 c chord length and hence larger solidity outperforms those with smaller chord lengths at low TSRs. However, their performances decrease significantly at TSRs above 2.5, resulting in up to 86.1% lower C\u0000 P values. The mixed chord lengths case was successful at achieving significantly higher C\u0000 P values at both TSR ranges with only a decrease of 3.03% in maximum C\u0000 P at its optimum TSR.","PeriodicalId":506254,"journal":{"name":"IOP Conference Series: Earth and Environmental Science","volume":"26 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141690376","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 : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012044
D. Cuevas, C. Pescos, L. Carrillo, A. Sibal, N. Guevarra
Clean water is an essential component for human survival. However, the growing global population and the relentless pace of industrial development have resulted in an alarming increase in water contamination. This renders many bodies of water as unfit for consumption or usage. In order to safeguard our natural resources, it is imperative that wastewater should be treated to follow a standard set by environmental specialists. In the Philippines, the enactment of the DAO 2021-19 has updated the requirements for release to more stringent standards. Because of this, a tertiary treatment, such as a phytoremediation bed, can be employed as an additional step in a wastewater treatment process. This study involves a comprehensive approach that consists of a phytoremediation setup, which includes the use of three plant species and specialized soil matrices, and a vortex system. The three plant species, Phragmites australis, Vetiveria zizanioides, and Canna indica are known for their capability for removal of the three pollutants, nitrates, phosphates and ammonia. The phytoremediation-vortex system was able to remove the pollutants and effectively reduce the pollutant concentration that the treated wastewater passes the standards for release. The predictive model, artificial neural network (ANN), was employed to assess the results. By using this technique, the study aimed to not only understand the intricate workings of the vortex system but also to optimise its performance for the effective reduction of pollutants, such as, nitrates, phosphates and ammonia, in wastewater. This research represents a critical step towards developing sustainable and efficient solutions for addressing the pressing challenges posed by water pollution, thereby fostering the availability of clean and potable water for human consumption and various industrial purposes.
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Pub Date : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012013
A. M. Fathoni, P. A. Hendrayanto, M. S. Aliefiansyah, N. Putra
The usage of electric vehicles has significantly reduced emissions of greenhouse gases and other pollutants. However, the high heat release generated by the electric vehicle batteries poses a challenge. To solve this problem, scientists have created a passive cooling thermal management system specifically for electric vehicle based on heat pipes, particularly loop heat pipes. A battery pack often consists of several battery modules, which results in multiple heat sources being dispersed according to their power capacity. Startup behavior of loop heat pipe has been investigated extensively in the literature. However, most of the studies use only one heat source. This paper aims to fill the research gap, particularly when the system is implemented in dual heat sources managed by only one evaporator. To achieve the research objectives, a custom loop heat pipe was constructed. This cooling system’s design is briefly described. The evaporator is made of copper, deionized water was selected as the working fluid because of its high merit number, which indicates strong performance as a heat pipe working fluid and the stainless-steel wire mesh serves as the porous wick. Battery simulator was built using aluminum material and a cartridge heater to mimic the heat produced by the battery. Two case studies were done. First, only one battery simulator was used. Second, two battery simulators were placed on both sides of the evaporator. A type-K thermocouple attached to the NI DAQ 9214 module was used to measure the temperature while the electric heat load varied between 10 W and 50 W. The study investigated the interaction between the heat load distribution and the startup behavior of the loop heat pipe. Startup behavior is crucial for the performance of the loop heat pipe. Based on the experimental results, the loop heat pipe demonstrates outstanding startup performance. It can effectively initiate operation even at a minimal heat load as low as 30 W for the first and second case study. The findings of the study indicate that the dual heat source arrangement effectively mitigates overshoot temperatures and enhances heat transfer performance by increasing the contact area.
电动汽车的使用大大减少了温室气体和其他污染物的排放。然而，电动汽车电池产生的高热量释放却带来了挑战。为了解决这个问题，科学家们利用热管，特别是环形热管，专门为电动汽车设计了一种被动冷却热管理系统。一个电池组通常由多个电池模块组成，这就导致多个热源根据其功率容量分散。文献中对环形热管的启动行为进行了广泛研究。然而，大多数研究只使用了一种热源。本文旨在填补这一研究空白，尤其是当系统采用仅由一个蒸发器管理的双热源时。为实现研究目标，我们建造了一个定制的环形热管。本文简要介绍了该冷却系统的设计。蒸发器由铜制成，去离子水被选为工作流体，因为它的优点数很高，表明其作为热管工作流体的性能很强，不锈钢丝网被用作多孔芯。使用铝材料和筒式加热器制作了电池模拟器，以模拟电池产生的热量。进行了两项案例研究。首先，只使用了一个电池模拟器。其次，在蒸发器的两侧放置了两个电池模拟器。当电热负荷在 10 W 和 50 W 之间变化时，使用连接到 NI DAQ 9214 模块的 K 型热电偶测量温度。启动行为对环形热管的性能至关重要。实验结果表明，环形热管具有出色的启动性能。在第一个和第二个案例研究中，即使热负荷低至 30 W，它也能有效地启动运行。研究结果表明，双热源布置可有效降低过冲温度，并通过增加接触面积提高传热性能。
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Pub Date : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012098
A. R. Villagracia
Hydrogen’s promise as a clean energy carrier is tempered by the challenges of efficient storage and safety concerns. While it offers an alternative to finite fossil fuel resources, current hydrogen storage methods, like cryo-compression and liquefaction, are often economically impractical. To tackle these issues, researchers are turning to nanotube materials (NTMs), crystalline substances with unique attributes ideal for hydrogen storage. Structural adaptability - NTMs can be precisely engineered for optimized hydrogen adsorption. These materials boast significant porosity, providing ample room for hydrogen molecules. NTMs offer a large surface area, enhancing their hydrogen adsorption capacity. NTMs employ weak van der Waals forces for hydrogen adsorption, enabling easy release via heat or pressure. Efforts are underway to enhance NTMs’ surface area and hydrogen uptake capabilities, along with a focus on mechanisms like the hydrogen spill-over for achieving high-density storage. NTMs go beyond storage; they can act as proton exchange membranes and fuel cell electrodes, making them versatile components in hydrogen-based energy systems. One strategy for improving NTM hydrogen storage involves introducing dopants or defects. Transition metals, due to their ability to attract and store hydrogen molecules in NTMs, are commonly explored. However, this addition may reduce the material’s gravimetric density, a critical practical consideration. In summary, research into NTMs and their potential for hydrogen storage via density functional theory is ongoing. This work explores strategies to enhance hydrogen storage, especially through transition metal doped NTMs. While these metals can improve hydrogen adsorption, the trade- offs in gravimetric density must be carefully weighed. Overall, this research contributes to the broader goal of harnessing hydrogen’s potential as a clean energy carrier, addressing the world’s growing energy needs.
{"title":"A comprehensive bibliometric review and analysis on the evolution of nanotube-based hydrogen storage materials via DFT simulations","authors":"A. R. Villagracia","doi":"10.1088/1755-1315/1372/1/012098","DOIUrl":"https://doi.org/10.1088/1755-1315/1372/1/012098","url":null,"abstract":"\u0000 Hydrogen’s promise as a clean energy carrier is tempered by the challenges of efficient storage and safety concerns. While it offers an alternative to finite fossil fuel resources, current hydrogen storage methods, like cryo-compression and liquefaction, are often economically impractical. To tackle these issues, researchers are turning to nanotube materials (NTMs), crystalline substances with unique attributes ideal for hydrogen storage. Structural adaptability - NTMs can be precisely engineered for optimized hydrogen adsorption. These materials boast significant porosity, providing ample room for hydrogen molecules. NTMs offer a large surface area, enhancing their hydrogen adsorption capacity. NTMs employ weak van der Waals forces for hydrogen adsorption, enabling easy release via heat or pressure. Efforts are underway to enhance NTMs’ surface area and hydrogen uptake capabilities, along with a focus on mechanisms like the hydrogen spill-over for achieving high-density storage. NTMs go beyond storage; they can act as proton exchange membranes and fuel cell electrodes, making them versatile components in hydrogen-based energy systems. One strategy for improving NTM hydrogen storage involves introducing dopants or defects. Transition metals, due to their ability to attract and store hydrogen molecules in NTMs, are commonly explored. However, this addition may reduce the material’s gravimetric density, a critical practical consideration. In summary, research into NTMs and their potential for hydrogen storage via density functional theory is ongoing. This work explores strategies to enhance hydrogen storage, especially through transition metal doped NTMs. While these metals can improve hydrogen adsorption, the trade- offs in gravimetric density must be carefully weighed. Overall, this research contributes to the broader goal of harnessing hydrogen’s potential as a clean energy carrier, addressing the world’s growing energy needs.","PeriodicalId":506254,"journal":{"name":"IOP Conference Series: Earth and Environmental Science","volume":"28 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141709413","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 : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012094
M Li, J G Gao, T Li, G D Liu, C C Hu, Y Q Liu
Window operating behaviour can improve indoor air quality, human thermal comfort, and building energy efficiency. Studies on occupants’ window opening behaviour in hot summer and warm winter region of China are limited and influencing factors and prediction models are not clear. Another limitation is the large number of proposed machine learning-based window opening behaviour models. However, the applicability and stability of these models in different datasets has not been proven. In response to these questions, modelling and field measurements were conducted in Quanzhou, China. Two different types of window-opening behaviour were noticed in the tested households. The first type was the all-closed windows, which had an average daily window-opening rate of 0.03%. The second type was the low-intensity window opening. The average daily window-opening rate was 10.6% and 9.1%, respectively. Then, the analysis of point biserial correlation coefficients revealed different reasons for closing windows in low-intensity households. One household closed the windows due to high outdoor humidity and the other mainly due to high outdoor wind speed and outdoor temperature. Furthermore, the suitable hyperparameters were screened for the support vector machine (SVM) model by K-fold cross-validation and grid search. The prediction model achieved an accuracy of 98.5% on the test set. Finally, the SVM model was trained and tested to verify the robustness of the model using data from the published literature. The prediction accuracy was improved from 0.7% to 7.4% compared to the different models used in the published literature.
{"title":"Modeling and analyzing patterns of residential manual window operation","authors":"M Li, J G Gao, T Li, G D Liu, C C Hu, Y Q Liu","doi":"10.1088/1755-1315/1372/1/012094","DOIUrl":"https://doi.org/10.1088/1755-1315/1372/1/012094","url":null,"abstract":"\u0000 Window operating behaviour can improve indoor air quality, human thermal comfort, and building energy efficiency. Studies on occupants’ window opening behaviour in hot summer and warm winter region of China are limited and influencing factors and prediction models are not clear. Another limitation is the large number of proposed machine learning-based window opening behaviour models. However, the applicability and stability of these models in different datasets has not been proven. In response to these questions, modelling and field measurements were conducted in Quanzhou, China. Two different types of window-opening behaviour were noticed in the tested households. The first type was the all-closed windows, which had an average daily window-opening rate of 0.03%. The second type was the low-intensity window opening. The average daily window-opening rate was 10.6% and 9.1%, respectively. Then, the analysis of point biserial correlation coefficients revealed different reasons for closing windows in low-intensity households. One household closed the windows due to high outdoor humidity and the other mainly due to high outdoor wind speed and outdoor temperature. Furthermore, the suitable hyperparameters were screened for the support vector machine (SVM) model by K-fold cross-validation and grid search. The prediction model achieved an accuracy of 98.5% on the test set. Finally, the SVM model was trained and tested to verify the robustness of the model using data from the published literature. The prediction accuracy was improved from 0.7% to 7.4% compared to the different models used in the published literature.","PeriodicalId":506254,"journal":{"name":"IOP Conference Series: Earth and Environmental Science","volume":"22 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141702734","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 : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012107
Y. Luo, M. A. H. Ali, N. N. N. Ghazali, W. T. Chong, H. C. Liu, H Chen, S. K. Zhang
The stable output of power and the effective control of stack temperature play a very important role in the durability and stability of fuel cell hybrid vehicles. In actual working conditions, energy management of power system and thermal management of Proton Exchange Membrane Fuel Cells (PEMFCs) need to be coordinated with each other to jointly ensure the efficient and stable operation of vehicles, however, most of the research in these two directions is independent. In response to the research gaps mentioned above, the concept of adaptability has been proposed for the first time with the aim of combining these two systems for research. This paper takes the fuel cell hybrid vehicle as the research object and establishes the energy management system and thermal management system model based on Matlab/Simulink software. In order to investigate the adaptability of energy management strategies to the temperature control system, two representative types of rule-based and optimization-based energy management strategies (power-following strategy, PFS, and adaptive equivalent hydrogen consumption minimization strategy, A-EHMS) are designed to be numerically simulated in the driving cycle condition of the UDDS, and then combined with the temperature control system of the fuel cell to comparatively analyze the above two types of energy management strategies from the perspectives of power allocation and the impact on the thermal management system. The results show that the PFS provides better protection for the battery under the same operating conditions. And from the perspective of fuel economy and adaptability to the temperature control system, the fuel consumption of A-EHMS is reduced by 12.5% and the adaptability to the temperature control system is improved by about 13.5% compared to PFS.
{"title":"Research on the adaptability of energy management to thermal management of PEMFCs","authors":"Y. Luo, M. A. H. Ali, N. N. N. Ghazali, W. T. Chong, H. C. Liu, H Chen, S. K. Zhang","doi":"10.1088/1755-1315/1372/1/012107","DOIUrl":"https://doi.org/10.1088/1755-1315/1372/1/012107","url":null,"abstract":"\u0000 The stable output of power and the effective control of stack temperature play a very important role in the durability and stability of fuel cell hybrid vehicles. In actual working conditions, energy management of power system and thermal management of Proton Exchange Membrane Fuel Cells (PEMFCs) need to be coordinated with each other to jointly ensure the efficient and stable operation of vehicles, however, most of the research in these two directions is independent. In response to the research gaps mentioned above, the concept of adaptability has been proposed for the first time with the aim of combining these two systems for research. This paper takes the fuel cell hybrid vehicle as the research object and establishes the energy management system and thermal management system model based on Matlab/Simulink software. In order to investigate the adaptability of energy management strategies to the temperature control system, two representative types of rule-based and optimization-based energy management strategies (power-following strategy, PFS, and adaptive equivalent hydrogen consumption minimization strategy, A-EHMS) are designed to be numerically simulated in the driving cycle condition of the UDDS, and then combined with the temperature control system of the fuel cell to comparatively analyze the above two types of energy management strategies from the perspectives of power allocation and the impact on the thermal management system. The results show that the PFS provides better protection for the battery under the same operating conditions. And from the perspective of fuel economy and adaptability to the temperature control system, the fuel consumption of A-EHMS is reduced by 12.5% and the adaptability to the temperature control system is improved by about 13.5% compared to PFS.","PeriodicalId":506254,"journal":{"name":"IOP Conference Series: Earth and Environmental Science","volume":"75 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141690765","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 : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012090
W. C. Yan, C J Yang, Y L Liu, L W Jin, X Cui, X. Z. Meng
The escalating energy consumption of data centers has led to a pressing need for energy-efficient cooling solutions. This paper presents a countercurrent dew point evaporative cooler (DPEC) for data center refrigeration. We developed and experimentally validated a numerical model for DPEC, then formulated regression models using the response surface method. These models link eight key design factors, including geometrical and operational factors, to three performance indices: cooling capacity per unit volume, coefficient of performance, and outlet primary air temperature. We assessed the extent of factor influence on these indices. By using these regression models as objective functions, we used the genetic algorithm for design optimization under two climatic conditions, resulting in various optimal parameter combinations. Our findings highlight the strong predictive accuracy of these models. In comparison to the original design, the optimal design achieved an improvement of 104.8%, an increase of 23.9%, and a reduction of 13.8% in the three indices.
{"title":"Optimizing a dew point evaporative cooler in data center applications","authors":"W. C. Yan, C J Yang, Y L Liu, L W Jin, X Cui, X. Z. Meng","doi":"10.1088/1755-1315/1372/1/012090","DOIUrl":"https://doi.org/10.1088/1755-1315/1372/1/012090","url":null,"abstract":"\u0000 The escalating energy consumption of data centers has led to a pressing need for energy-efficient cooling solutions. This paper presents a countercurrent dew point evaporative cooler (DPEC) for data center refrigeration. We developed and experimentally validated a numerical model for DPEC, then formulated regression models using the response surface method. These models link eight key design factors, including geometrical and operational factors, to three performance indices: cooling capacity per unit volume, coefficient of performance, and outlet primary air temperature. We assessed the extent of factor influence on these indices. By using these regression models as objective functions, we used the genetic algorithm for design optimization under two climatic conditions, resulting in various optimal parameter combinations. Our findings highlight the strong predictive accuracy of these models. In comparison to the original design, the optimal design achieved an improvement of 104.8%, an increase of 23.9%, and a reduction of 13.8% in the three indices.","PeriodicalId":506254,"journal":{"name":"IOP Conference Series: Earth and Environmental Science","volume":"181 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141708376","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 : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012095
I. A. Dharma, M. G. Z. Haikal, M. Ridlwan, S. A. Dewanto, M. A. Rahman
The tray dryer for the cocoa bean drying process is a solution to overcome conventional drying methods that rely on solar heat. The tray dryer is expected to facilitate the cocoa farmers to dry cocoa beans because it is faster and does not depend on weather conditions. However, even though the current condition of the tray dryer can reduce the energy consumption of drying cocoa beans (from Gunung Kidul, Yogyakarta, Indonesia) compared to the solar heat method, it remains unknown whether the cocoa beans drying quality is good enough. Therefore, this research analyzed the heat transfer phenomena of the cocoa drying process using the computational simulation method to re-design the current tray dryer design so that the new design can fit the drying characteristic of the cocoa bean and reduce energy consumption. As a result, for the air velocity of 25.91 m/s and the ½ opening of the gas valve in 10 minutes, which is already at steady-state conditions, the temperature distribution in the existing tray dryer is not suitable with the characteristics of the cocoa beans drying process. The temperature can be increased by reducing the airflow velocity or increasing the heating value by opening the valve. However, with a new design, the temperature can be increased by up to 37.00% at a velocity of 25.91 m/s with a ½ gas valve opening. Furthermore, the new design can achieve the same conditions as the existing design by only using an opening for a 1/8 gas valve. Thus, using the new design, the tray dryer can achieve the drying characteristics of cocoa beans and reduce energy consumption.
用于可可豆烘干过程的托盘式烘干机是克服依赖太阳热能的传统烘干方法的一种解决方案。托盘式烘干机预计将方便可可种植农烘干可可豆，因为它速度更快，而且不依赖天气条件。然而，尽管与太阳能加热法相比，托盘式烘干机目前的状况可以减少烘干可可豆（产自印度尼西亚日惹的 Gunung Kidul）的能耗，但可可豆的烘干质量是否足够好仍然是个未知数。因此，本研究利用计算模拟方法分析了可可烘干过程中的传热现象，以重新设计当前的托盘式烘干机设计，使新设计既能符合可可豆的烘干特性，又能降低能耗。结果表明，在气流速度为 25.91 米/秒、气体阀门在 10 分钟内打开 1/2（这已经是稳态条件）的情况下，现有托盘式干燥机中的温度分布与可可豆干燥过程的特点不相适应。可以通过降低气流速度或打开阀门增加热值来提高温度。然而，采用新设计后，在气流速度为 25.91 米/秒、气阀开度为 ½ 的情况下，温度最高可提高 37.00%。此外，新设计只需使用 1/8 气阀开口，就能达到与现有设计相同的条件。因此，采用新设计的托盘式干燥机既能达到可可豆的干燥特性，又能降低能耗。
{"title":"Heat transfer simulation for re-design of tray dryer to reduce the energy consumption in the cocoa bean drying process","authors":"I. A. Dharma, M. G. Z. Haikal, M. Ridlwan, S. A. Dewanto, M. A. Rahman","doi":"10.1088/1755-1315/1372/1/012095","DOIUrl":"https://doi.org/10.1088/1755-1315/1372/1/012095","url":null,"abstract":"\u0000 The tray dryer for the cocoa bean drying process is a solution to overcome conventional drying methods that rely on solar heat. The tray dryer is expected to facilitate the cocoa farmers to dry cocoa beans because it is faster and does not depend on weather conditions. However, even though the current condition of the tray dryer can reduce the energy consumption of drying cocoa beans (from Gunung Kidul, Yogyakarta, Indonesia) compared to the solar heat method, it remains unknown whether the cocoa beans drying quality is good enough. Therefore, this research analyzed the heat transfer phenomena of the cocoa drying process using the computational simulation method to re-design the current tray dryer design so that the new design can fit the drying characteristic of the cocoa bean and reduce energy consumption. As a result, for the air velocity of 25.91 m/s and the ½ opening of the gas valve in 10 minutes, which is already at steady-state conditions, the temperature distribution in the existing tray dryer is not suitable with the characteristics of the cocoa beans drying process. The temperature can be increased by reducing the airflow velocity or increasing the heating value by opening the valve. However, with a new design, the temperature can be increased by up to 37.00% at a velocity of 25.91 m/s with a ½ gas valve opening. Furthermore, the new design can achieve the same conditions as the existing design by only using an opening for a 1/8 gas valve. Thus, using the new design, the tray dryer can achieve the drying characteristics of cocoa beans and reduce energy consumption.","PeriodicalId":506254,"journal":{"name":"IOP Conference Series: Earth and Environmental Science","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141712137","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 : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012039
A. Zandberga, J. Gušča, D. Blumberga, S. Kalniņš
The growing impact of the healthcare sector and its environmental consequences (energy-intensive processes, material consumption and waste generation) require rapid actions to be implemented widely. To meet the environmental and climate change challenges faced by the healthcare sector, this review paper discusses how circularity frameworks can be applied to medical textile waste. This review paper explores existing circularity frameworks to address the challenges resulting from textile waste in the healthcare sector. Textile waste, primarily originating from medical garments (scrubs, isolation gowns), patient apparel and bedding, surgical textiles, wound care textiles, personal protective equipment (masks, gowns and aprons), textiles for diagnostic purposes (medical imaging), and textiles for hygiene and sanitation, present an environmental impact due to their non-biodegradability and energy-intensive production processes. This paper conducts a thorough mini review of those circularity frameworks applied to healthcare textile waste along the product’s life cycle within hospitals. The review focuses on the current waste management practices of the hospitals and evaluates innovative circular economy interventions. Case studies and pilot projects that have successfully operated circularity frameworks for managing healthcare textiles waste are included in the review to provide practical insight.
{"title":"Mini review on circularity framework for textile waste in healthcare","authors":"A. Zandberga, J. Gušča, D. Blumberga, S. Kalniņš","doi":"10.1088/1755-1315/1372/1/012039","DOIUrl":"https://doi.org/10.1088/1755-1315/1372/1/012039","url":null,"abstract":"\u0000 The growing impact of the healthcare sector and its environmental consequences (energy-intensive processes, material consumption and waste generation) require rapid actions to be implemented widely. To meet the environmental and climate change challenges faced by the healthcare sector, this review paper discusses how circularity frameworks can be applied to medical textile waste. This review paper explores existing circularity frameworks to address the challenges resulting from textile waste in the healthcare sector. Textile waste, primarily originating from medical garments (scrubs, isolation gowns), patient apparel and bedding, surgical textiles, wound care textiles, personal protective equipment (masks, gowns and aprons), textiles for diagnostic purposes (medical imaging), and textiles for hygiene and sanitation, present an environmental impact due to their non-biodegradability and energy-intensive production processes. This paper conducts a thorough mini review of those circularity frameworks applied to healthcare textile waste along the product’s life cycle within hospitals. The review focuses on the current waste management practices of the hospitals and evaluates innovative circular economy interventions. Case studies and pilot projects that have successfully operated circularity frameworks for managing healthcare textiles waste are included in the review to provide practical insight.","PeriodicalId":506254,"journal":{"name":"IOP Conference Series: Earth and Environmental Science","volume":"243 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141711539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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