Article
Thermodynamics
Devendra Raut, Saurabh Lanjewar, Vilas R. Kalamkar
Summary: This study investigates the effect of geometric and operating parameters on the charging of phase change material (PCM) in a vertical helical coiled latent heat storage (LHS) system. The results show that increasing the coil spacing and HTF inlet temperature can improve the charging process, while varying the HTF flow rate has no significant impact on the charging rate of the PCM.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Green & Sustainable Science & Technology
Salwa Bouadila, Sara Baddadi, Tauseef-ur Rehman, Rabeb Ayed
Summary: This study explores the improvement of efficiency in evacuated tube solar collectors through the addition of reflectors and thermal storage units. The performance of different designs in various regions of Tunisia is evaluated, and an energy balance model is established. Future research directions are also recommended.
Article
Energy & Fuels
Mahdi Momeni, Amir Fartaj
Summary: This paper introduces a novel PCM-to-air and liquid heat exchanger for thermal energy storage, which can provide a hybrid heat source and improve thermal system performance. Numerical simulations are used to analyze the heat transfer characteristics and phase change process, and the effect of airflow variation on the thermal response is studied. Experimental results demonstrate that the PCM can store and release excess heat during charging and discharging processes, providing extra heating time for the airside.
JOURNAL OF ENERGY STORAGE
(2023)
Article
Energy & Fuels
Rejane De Cesaro Oliveski, Alexandre de Quadro Tacques Filho, Ionatan Anton Schroer
Summary: There are many advantages to using thermal storage with phase change materials (PCM) and incorporating fins for heat transfer optimization. This study analyzes the effects of fin aspect ratio and positioning on the melting and solidification processes in a rectangular cavity. It was found that higher fin aspect ratios result in higher melting and solidification rates, especially in lower cavity positions.
JOURNAL OF ENERGY STORAGE
(2022)
Article
Thermodynamics
Yang Tian, Xianglei Liu, Hangbin Zheng, Qiao Xu, Zhonghui Zhu, Qinyang Luo, Chao Song, Ke Gao, Haichen Yao, Chunzhuo Dang, Yimin Xuan
Summary: A bionic design of a PCM capsule inspired by mitochondrion is proposed for fast latent heat storage. The mitochondrion-shaped capsule has the fastest thermal storage rate and the lowest drag force among different PCM capsules, significantly reducing the melting time.
Article
Energy & Fuels
Andreas Koenig-Haagen, Moritz Faden, Gonzalo Diarce
Summary: Macro-encapsulation of phase change material is a promising solution for enhancing the thermal power of latent heat thermal energy storage systems. However, simulating the charging process using detailed CFD models is computationally expensive. This study presents a new approach to create a reduced order model using look-up tables, which significantly increases the accuracy of the system simulation.
JOURNAL OF ENERGY STORAGE
(2023)
Article
Thermodynamics
Dwi Rahmalina, Reza Abdu Rahman, Ismail
Summary: This study evaluates the application of form-stabilized phase change material (SSPCM) in active latent heat storage (ALHS) systems. It is found that using high-density polyethylene (HDPE) and styrene-butadiene-styrene (SBS) as supporting materials improves thermal conductivity and supercooling degree of SSPCM. Evaluation using a tube-in-shell heat exchanger shows that composite SSPCM has a lower temperature gradient and higher storage efficiency.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Green & Sustainable Science & Technology
Mohamed El Habib Amagour, Mounir Bennajah, Adil Rachek
Summary: This study presents a numerical investigation of heat transfer performance inside a compact finned-tube heat exchanger used in latent heat storage. The results show that adjusting operational and design parameters can significantly impact the charging and discharging performance.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Energy & Fuels
Yasser Harmen, Younes Chhiti, Fatima Ezzahrae M'Hamdi Alaoui, Fouad Bentiss, Mohamed El Khouakhi, Charafeddine Jama, Sophie Duquesne, Mohammed Bensitel, Laurent Deshayes
Summary: Thermal energy storage technology utilizing Phase Change Materials (PCM) is studied extensively in this paper to optimize energy resources and enhance energy recovery. The study focuses on analyzing multiphysics phenomena of different regenerator configurations and investigating parameters such as thermal properties and energy storage distribution. Experimental and numerical analysis are conducted to provide important insights into passive storage systems.
JOURNAL OF ENERGY STORAGE
(2021)
Article
Construction & Building Technology
Rok Kozelj, Urska Mlakar, Eva Zavrl, Uros Stritih, Rok Stropnik
Summary: In the building sector, a significant amount of energy is used for heating and cooling, with residential buildings accounting for a large portion. Utilizing efficient technologies and heat storage materials, such as phase change materials, can improve energy efficiency and enable a higher utilization of renewable energy sources like solar energy. This can help reduce energy consumption and address the challenge of energy demand temporal divergence.
ENERGY AND BUILDINGS
(2021)
Article
Engineering, Multidisciplinary
Mohamed Houcine Dhaou, Sofiene Mellouli, Faisal Alresheedi, Yassine El-Ghoul
Summary: In this study, the performance of a Solar Water Tank (SWT) integrated with Nano-enhanced Phase Change Material (Ne-PCM) and a Stirrer was experimentally assessed. Two configurations of SWT/Ne-PCMs, a spiral-type and a jacketed shell-type heat exchangers, were designed and developed. The experimental results showed that the completion time for the SWT/Ne-PCM charging and discharging processes was reduced by 12.5% and 23.51% respectively, when a stirrer and a coil were used.
ALEXANDRIA ENGINEERING JOURNAL
(2022)
Article
Energy & Fuels
Ashutosh Sharma, Ranga Pitchumani, Ranchan Chauhan
Summary: This article presents a comparative investigation of different horizontal shell and tube latent heat storage unit (ST-LHSU) designs for melting/solidification performances. The results show that Design-IV has a significantly faster melting rate than Design-III and Design-I, completing the process 25.5% and 37.4% faster, respectively. Furthermore, Design-I is the most effective design for solidification, achieving complete solidification 3.65%, 19.57%, and 45.02% faster than Designs-II, III, and IV. Additionally, modification in Design-I reduces the total thermal cycle time by 24.58%, 37.94%, and 40.21% compared to the original Design-I, Design-III, and Design-IV.
JOURNAL OF ENERGY STORAGE
(2023)
Review
Green & Sustainable Science & Technology
B. Lamrani, K. Johannes, F. Kuznik
Summary: This paper reviews the studies on phase change materials (PCMs) integrated in building walls over the past decade (2011-2020), highlighting their potential for reducing indoor air temperature fluctuations and energy consumption. However, further research is needed to consider factors such as occupant behavior, economic viability, and environmental impact.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2021)
Article
Thermodynamics
Madhu Agarwal, Brijesh Kuldeep, Annie P. John, Karishma Maheshwari, Rajeev Dohare
Summary: In this study, beeswax was used as a phase change material to store heat, and its thermal conductivity and melting point were improved by adding nanoparticles and other phase change materials. FeO nanoparticles were found to give the best result for enhancing thermal conductivity, and the addition of coconut oil helped lower the melting point of the beeswax. The composite of beeswax and coconut oil with FeO nanoparticles showed the best performance in terms of charging time reduction.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Review
Energy & Fuels
Debasree Ghosh, Joyjeet Ghose, Pulak Datta, Pallavi Kumari, Suraj Paul
Summary: The use of phase change materials (PCMs) is crucial for energy storage and meeting basic needs. Improving the thermal properties of PCMs through additives and encapsulation can enhance their storage capacity. Encapsulated PCMs and PCM composites have shown superior performance in latent heat thermal energy storage.
JOURNAL OF ENERGY STORAGE
(2022)
Article
Chemistry, Multidisciplinary
Danny Mueller, Christian Knoll, Georg Gravogl, Daniel Lager, Jan M. Welch, Elisabeth Eitenberger, Gernot Friedbacher, Andreas Werner, Werner Artner, Michael Harasek, Ronald Miletich, Peter Weinberger
Article
Energy & Fuels
Verena Halmschlager, Stefan Muellner, Rene Hofmann
Summary: The study developed a mechanistic grey-box model for sensible thermal energy storage, with the extended model II showing excellent performance among multiple models. Compared to data-driven and physical models, the grey-box models demonstrated higher accuracy and lower computational effort.
Article
Energy & Fuels
Verena Sulzgruber, Miriam Unterlass, Tobia Cavalli, Heimo Walter
Summary: This article presents a concept of micro encapsulated phase change material to improve the economic and technical aspects of high-temperature thermal energy storage. Through coating experiments and performance tests under different process conditions, the mechanical and thermal properties of the material are determined. Furthermore, a rough layout of a thermal energy storage system using the produced particles is presented and compared with a common sensible thermal energy storage.
JOURNAL OF ENERGY RESOURCES TECHNOLOGY-TRANSACTIONS OF THE ASME
(2022)
Article
Energy & Fuels
Daniel Halmschlager, Anton Beck, Sophie Knoettner, Martin Koller, Rene Hofmann
Summary: This paper presents a new combined optimization approach to support decision-making in retrofit scenarios of interlinked industrial energy systems. By linking models for optimal design of supply systems and heat recovery systems with operational constraints and formulating it as a single combined mixed-integer linear programming (MILP) problem, the approach provides a cost-effective solution for a transition to more efficient energy use and an increased share of renewable sources in a typical industrial process.
Article
Energy & Fuels
Leopold Prendl, Rene Hofmann
Summary: The use of mathematical optimization methods like HENS for integrating heat pumps and storage in energy-intensive industries can significantly reduce costs and external energy demand. The authors demonstrated this potential through four representative industrial processes, making a valuable contribution to future research in the field of HENS.
Article
Computer Science, Interdisciplinary Applications
Jan A. Stampfli, Benjamin H. Y. Ong, Donald G. Olsen, Beat Wellig, Rene Hofmann
Summary: An evolutionary two-level algorithm for heat exchanger network retrofit was proposed and successfully applied to an industrial case study, reducing its total annual cost significantly.
COMPUTERS & CHEMICAL ENGINEERING
(2022)
Article
Engineering, Chemical
Daniel Lager, Edith Haslinger, Robin Friedrich, Stefan Hoyer, Doris Rupprecht
Summary: Urban heat islands occur in inner-city areas due to small green areas, excess solar heat, and low air circulation. One solution is to harvest excess solar heat through shallow absorber ducts and store it for later use in borehole heat exchanger fields. Accurate knowledge of the subsurface's thermophysical properties is crucial in designing and configuring a thermal energy storage system using borehole heat exchangers.
Article
Engineering, Chemical
Anton Beck, Sophie Knoettner, Julian Unterluggauer, Daniel Halmschlager, Rene Hofmann
Summary: This article presents a new optimization model that allows for the simultaneous optimization of the design and operation of a supply and heat recovery system and production scheduling. The model was used to retrofit a small brewery's energy system and identify decarbonization measures for different future scenarios.
Article
Chemistry, Multidisciplinary
Lukas Kasper, Felix Birkelbach, Paul Schwarzmayr, Gernot Steindl, Daniel Ramsauer, Rene Hofmann
Summary: Digitalization and concepts like digital twins have great potential to improve efficiency in the energy sector, but there is currently a lack of standardized framework for implementing digital twins in industrial energy systems. This study proposes a platform based on a five-dimensional digital twin modeling concept that meets the requirements of industrial energy systems and addresses current technical implementation barriers.
APPLIED SCIENCES-BASEL
(2022)
Article
Energy & Fuels
Paul Schwarzmayr, Felix Birkelbach, Heimo Walter, Rene Hofmann
Summary: The waste heat potential from industrial processes is significant and can contribute to mitigating climate change. A packed bed thermal energy storage system is a low-cost technology that can store and utilize waste heat from industrial processes. By studying the standby mode characteristics, the efficiency of the system can be improved.
Article
Energy & Fuels
Carlotta Tubeuf, Felix Birkelbach, Anton Maly, Rene Hofmann
Summary: In this work, RL is utilized to control the blow-out process of a hydraulic machine during pump start-up and when operating in synchronous condenser mode. The concept of using a digital twin platform enables the safe and effective transfer of the algorithm's learning strategy. The successful implementation of RL in a test environment is presented and future research on the transfer to a model test rig is discussed.
Article
Computer Science, Information Systems
Dominik Pernsteiner, Verena Halmschlager, Alexander Schirrer, Rene Hofmann, Stefan Jakubek
Summary: This paper proposes a novel cooperation concept between hierarchical layers to achieve optimal expected operating costs by exchanging sensitivity information between optimization layers.
Article
Electrochemistry
Markus Koller, Johanna Unterkofler, Gregor Glanz, Daniel Lager, Alexander Bergmann, Hartmut Popp
Summary: The pipe method is commonly used to measure the radial thermal conductivity of cylindrical objects, but it can lead to high uncertainties. To verify the measurement uncertainties and show a possible range of results, an alternative method was introduced. By numerically calculating thermal conductivity and parameterizing a model, the uncertainties and issues inherent in the pipe method were revealed.
Article
Electrochemistry
Anish Raj Kathribail, Arlavinda Rezqita, Daniel Lager, Raad Hamid, Yuri Surace, Maitane Berecibar, Joeri Van Mierlo, Annick Hubin, Marcus Jahn, Juergen Kahr
Summary: Coating conducting polymers onto active cathode materials has been shown to improve electrochemical performance and cycling stability, particularly in nickel-rich NMC622. The impact of heat treatment on the performance was studied systematically, with a heat treatment at 400 degrees C leading to enhanced reversibility and capacity retention, resulting in nearly 50% increase in discharge capacity for carbon coated NMC at 10C compared to uncoated samples. This study highlights the synergistic effects of a furfuryl polymer coating and subsequent calcination on improving the electrochemical performance of nickel-rich NMC622.
Article
Computer Science, Information Systems
Leopold Prendl, Lukas Kasper, Markus Holzegger, Rene Hofmann
Summary: Increasing flexibility and efficiency in energy-intensive industrial processes is crucial for a decarbonized energy system, and accurate prediction of unit behavior is essential. A novel framework for automated data-driven model adaption improves storage output prediction and provides a foundation for live condition monitoring, fault prediction, predictive maintenance, and operation optimization.
Article
Energy & Fuels
Shitong Fang, Houfan Du, Tao Yan, Keyu Chen, Zhiyuan Li, Xiaoqing Ma, Zhihui Lai, Shengxi Zhou
Summary: This paper proposes a new type of nonlinear VIV energy harvester (ANVEH) that compensates for the decrease in peak energy output at low wind speeds by introducing an auxiliary structure. Theoretical and experimental results show that ANVEH performs better than traditional nonlinear VIV energy harvesters under various system parameter variations.
Article
Energy & Fuels
Wei Jiang, Shuo Zhang, Teng Wang, Yufei Zhang, Aimin Sha, Jingjing Xiao, Dongdong Yuan
Summary: A standardized method was developed to evaluate the availability of solar energy resources in road areas, which combined the Analytic Hierarchy Process (AHP) and the Geographic Information System (GIS). By analyzing critical factors and using a multi-indicator evaluation method, the method accurately evaluated the utilization of solar energy resources and guided the optimal location selection for road photovoltaic (PV) projects. The results provided guidance for the application of road PV projects and site selection for route corridors worldwide, promoting the integration of transportation and energy.
Article
Energy & Fuels
Chang Liu, Jacob A. Wrubel, Elliot Padgett, Guido Bender
Summary: The study investigates the effects of coating defects on the performance of the anode porous transport layer (PTL) in water electrolyzers. The results show that an increasing fraction of uncoated regions on the PTL leads to decreased cell performance, with continuous uncoated regions having a more severe impact compared to multiple thin uncoated strips.
Article
Energy & Fuels
Marcos Tostado-Veliz, Xiaolong Jin, Rohit Bhakar, Francisco Jurado
Summary: In this paper, a coordinated charging price mechanism for clusters of parking lots is proposed. The research shows that enabling vehicle-to-grid characteristics can bring significant economic benefits for users and the cluster coordinator, and vehicle-to-grid impacts noticeably on the risk-averse character of the uncertainty-aware strategies. The developed pricing mechanism can reduce the cost for users, avoiding to directly translate the energy cost to charging points.
Article
Energy & Fuels
Duan Kang
Summary: Building an energy superpower is a key strategy for China and a long-term goal for other countries. This study proposes an evaluation system and index for measuring energy superpower, and finds that China has significantly improved its ranking over the past 21 years, surpassing other countries.
Article
Energy & Fuels
Fucheng Deng, Yifei Wang, Xiaosen Li, Gang Li, Yi Wang, Bin Huang
Summary: This study investigated the synergistic blockage mechanism of sand and hydrate in gravel filling layer and the evolution of permeability in the layer. Experimental models and modified permeability models were established to analyze the effects of sand particles and hydrate formation on permeability. The study provided valuable insights for the safe and efficient exploitation of hydrate reservoirs.
Article
Energy & Fuels
Hao Wang, Xiwen Chen, Natan Vital, Edward Duffy, Abolfazl Razi
Summary: This study proposes a HVAC energy optimization model based on deep reinforcement learning algorithm. It achieves 37% energy savings and ensures thermal comfort for open office buildings. The model has a low complexity, uses a few controllable factors, and has a short training time with good generalizability.
Article
Energy & Fuels
Moyue Cong, Yongzhuo Gao, Weidong Wang, Long He, Xiwang Mao, Yi Long, Wei Dong
Summary: This study introduces a multi-strategy ultra-wideband energy harvesting device that achieves high power output without the need for external power input. By utilizing asymmetry, stagger array, magnetic coupling, and nonlinearity strategies, the device maintains a stable output voltage and high power density output at non-resonant frequencies. Temperature and humidity monitoring are performed using Bluetooth sensors to adaptively assess the device.
Article
Energy & Fuels
Tianshu Dong, Xiudong Duan, Yuanyuan Huang, Danji Huang, Yingdong Luo, Ziyu Liu, Xiaomeng Ai, Jiakun Fang, Chaolong Song
Summary: Electrochemical water splitting is crucial for hydrogen production, and improving the hydrogen separation rate from the electrode is essential for enhancing water electrolyzer performance. However, issues such as air bubble adhesion to the electrode plate hinder the process. Therefore, a methodology to investigate the two-phase flow within the electrolyzer is in high demand. This study proposes using a microfluidic system as a simulator for the electrolyzer and optimizing the two-phase flow by manipulating the micro-structure of the flow.
Article
Energy & Fuels
Shuo Han, Yifan Yuan, Mengjiao He, Ziwen Zhao, Beibei Xu, Diyi Chen, Jakub Jurasz
Summary: Giving full play to the flexibility of hydropower and integrating more variable renewable energy is of great significance for accelerating the transformation of China's power energy system. This study proposes a novel day-ahead scheduling model that considers the flexibility limited by irregular vibration zones (VZs) and the probability of flexibility shortage in a hydropower-variable renewable energy hybrid generation system. The model is applied to a real hydropower station and effectively improves the flexibility supply capacity of hydropower, especially during heavy load demand in flood season.
Article
Energy & Fuels
Zhen Wang, Kangqi Fan, Shizhong Zhao, Shuxin Wu, Xuan Zhang, Kangjia Zhai, Zhiqi Li, Hua He
Summary: This study developed a high-performance rotary energy harvester (AI-REH) inspired by archery, which efficiently accumulates and releases ultralow-frequency vibration energy. By utilizing a magnetic coupling strategy and an accumulator spring, the AI-REH achieves significantly accelerated rotor speeds and enhanced electric outputs.
Article
Energy & Fuels
Yi Yang, Qianyi Xing, Kang Wang, Caihong Li, Jianzhou Wang, Xiaojia Huang
Summary: In this study, a novel hybrid Quantile Regression (QR) model is proposed for Probabilistic Load Forecasting (PLF). The model integrates causal dilated convolution, residual connection, and Bidirectional Long Short-Term Memory (BiLSTM) for multi-scale feature extraction. In addition, a Combined Probabilistic Load Forecasting System (CPLFS) is proposed to overcome the inherent flaws of relying on a single model. Simulation results show that the hybrid QR outperforms traditional models and CPLFS exceeds the best benchmarks in terms of prediction accuracy and stability.
Article
Energy & Fuels
Wen-Jiang Zou, Young-Bae Kim, Seunghun Jung
Summary: This paper proposes a dynamic prediction model for capacity fade in vanadium redox flow batteries (VRFBs). The model accurately predicts changes in electrolyte volume and capacity fade, enhancing the competitiveness of VRFBs in energy storage applications.
Article
Energy & Fuels
Yuechao Ma, Shengtie Wang, Guangchen Liu, Guizhen Tian, Jianwei Zhang, Ruiming Liu
Summary: This paper focuses on the balance of state of charge (SOC) among multiple battery energy storage units (MBESUs) and bus voltage balance in an islanded bipolar DC microgrid. A SOC automatic balancing strategy is proposed considering the energy flow relationship and utilizing the adaptive virtual resistance algorithm. The simulation results demonstrate the effectiveness of the proposed strategy in achieving SOC balancing and decreasing bus voltage unbalance.
Article
Energy & Fuels
Raad Z. Homod, Basil Sh. Munahi, Hayder Ibrahim Mohammed, Musatafa Abbas Abbood Albadr, Aissa Abderrahmane, Jasim M. Mahdi, Mohamed Bechir Ben Hamida, Bilal Naji Alhasnawi, A. S. Albahri, Hussein Togun, Umar F. Alqsair, Zaher Mundher Yaseen
Summary: In this study, the control problem of the multiple-boiler system (MBS) is formulated as a dynamic Markov decision process and a deep clustering reinforcement learning approach is applied to obtain the optimal control policy. The proposed strategy, based on bang-bang action, shows superior response and achieves more than 32% energy saving compared to conventional fixed parameter controllers under dynamic indoor/outdoor actual conditions.
