Article
Construction & Building Technology
Chandan Swaroop Meena, Amit Nandan Prajapati, Ashwani Kumar, Manoj Kumar
Summary: This manuscript presents a study on flow escalation for a Solar Assisted Heat Pump Water Heater (SAHPWH) based on experimental data, aiming to increase building energy efficiency. The experiments showed that using single glazing can achieve the same heat gains, and a specific solar assisted heat pump system was tested to supply a large amount of hot water in a short time. The study also found a relationship between the collector efficiency factor, absorber, and tube spacing.
Article
Energy & Fuels
Chandan Swaroop Meena, Binju P. Raj, Lohit Saini, Nehul Agarwal, Aritra Ghosh
Summary: In this study, parametric optimization was performed on a solar-assisted heat pump system for water heating in colder climates with minimal solar radiation. Results showed that double glazing is more efficient than single glazing, and positioning the evaporator tube below the absorber plate increases the COP. This energy-saving system is particularly suitable for areas abundant in solar radiation.
Review
Energy & Fuels
Kutbay Sezen, Afsin Gungor
Summary: Solar assisted heat pump (SAHP) systems have gained popularity due to their improved performance by utilizing solar energy. This study reviews 77 recent studies to compare SAHP systems in terms of performance, structure, and cost, and recommends direct expansion systems for optimal utilization of solar and air as heat sources under solar irradiation below 400 W/m2.
Article
Chemistry, Multidisciplinary
Evangelos Bellos, Panagiotis Lykas, Dimitrios Tsimpoukis, Dimitrios N. Korres, Angeliki Kitsopoulou, Michail Gr. Vrachopoulos, Christos Tzivanidis
Summary: The investigation aims to thoroughly analyze and optimize a solar-assisted heat pump heating unit in Athens, Greece, which uses a high-temperature heat pump for radiative terminal units and achieves high thermal comfort standards. The system consists of solar thermal collectors, a thermal storage tank, auxiliary electrical thermal resistance, and a high-temperature heat pump. Economic optimization reveals that the optimal design includes 35 m(2) of solar thermal collectors and a 2 m(3) storage tank to meet a total heating demand of 6785 kWh. The life cycle cost is calculated at 22,694 EUR with a system coefficient of performance of 2.95 and a mean solar thermal efficiency of 31.60%. On the other hand, multi-objective optimization indicates that the optimum design is a solar field of 50 m(2) connected to a 3 m(3) thermal tank, resulting in a life cycle cost of 24,084 EUR, a system coefficient of performance of 4.07, and a mean solar thermal efficiency of 25.33%.
APPLIED SCIENCES-BASEL
(2023)
Article
Green & Sustainable Science & Technology
Marco Noro
Summary: This paper evaluates the possibility of using evacuated tube collectors to drive an absorption heat pump as a chiller, considering both energy and economic aspects. The results show that the best plant configuration achieves a primary energy ratio of 4.75 in a cold and cloudy climate, and 5.9 in a warmer and clearer sky climate. An economic analysis on the actual investment costs is also presented, taking into account cost reduction based on recent price lists.
Article
Thermodynamics
Minwoo Lee, Changho Han, Soonbum Kwon, Yongchan Kim
Summary: This study investigates the heat trading between two massive prosumers using solar and ground energy systems in Korea. The simulation results show that heat trading can increase the share of renewable energy provision and reduce total costs for prosumers. Increasing the size of solar collectors and ground-source heat pumps can further enhance the effectiveness of the trading. However, determining the heat sales cost between the prosumers is crucial to ensure the benefits for both parties.
Article
Energy & Fuels
Shengqing Xiao, Dimitri Nefodov, Mark O. O. McLinden, Markus Richter, Thorsten Urbaneck
Summary: In the context of global energy transition, solar energy has great potential as a sustainable heat source. Combining renewable energy sources and heat pump technology, solar district heating systems can transform existing residential areas into zero-emission districts. However, the use of high GWP commercial working fluids in future refrigeration systems is restricted. A study in Germany evaluated refrigerant candidates for heat-pump-based solar district heating systems and found that R1234ze(E) exhibits the best combination of thermodynamic, environmental, and safety properties.
Article
Thermodynamics
Shahab Eslami, Younes Noorollahi, Mousa Marzband, Amjad Anvari-Moghaddam
Summary: This study presents an effective model for planning and utilizing a district heating system and applies it to a province in Turkey. It predicts the heating load and evaluates suitable regions for establishing district heating systems using machine learning and geographic information system methods. Different scenarios are analyzed to determine the most effective heating solution in terms of economic and environmental aspects.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Chemistry, Physical
Chuanhui Zhu, Shubin Yan, Xiaodong Dong, Wei Zhang, Biyi Huang, Yang Cui
Summary: With the rapid development of industrialization, the excessive use of fossil fuels has caused issues like increased greenhouse gas emissions and energy shortages, leading to a shift towards the development and utilization of renewable energy. Solar heat pump heating technology has become the development direction for clean heating in northern regions in winter, but faces challenges due to the intermittent nature of solar energy and the impact of low-valley electricity policies.
Article
Thermodynamics
Lin Fu, Yonghong Li, Yanting Wu, Xiaoyin Wang, Yi Jiang
Summary: The study introduces a low carbon district heating system that is suitable for large cities in Northern China, aiming to reduce energy consumption, emissions, and improve the economics of the heating systems.
Article
Energy & Fuels
Daniel Zinsmeister, Thomas Licklederer, Franz Christange, Peter Tzscheutschler, Vedran S. Peric
Summary: This paper investigates the influence of different system configurations in prosumer-based district heating networks on network operation and provides decision guidance for selecting the most suitable configuration through simulation analysis.
Article
Environmental Sciences
Yue Li, Yuzhou Tang, Liang Qiao, Mengyue Liu, Leping Chen, Xueliang Yuan, Qingsong Wang, Qiao Ma
Summary: Solar heating is considered a clean and low-carbon heating method, but its high initial investment hinders its promotion in economically underdeveloped areas. The Chinese government proposes to widely adopt solar heating to meet the heating demands of rural residents. However, the research findings suggest that solar heating may not be the best solution for rural clean heating, as other projects with equal investment can bring more benefits.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Thermodynamics
Sameh Agrebi, Ridha Chargui, Bourhan Tashtoush, AmenAllah Guizani
Summary: This study presents a comparative investigation of a solar-assisted heat pump and a conventional heat pump heating system, utilizing numerical and experimental studies. Results show that the solar collector significantly affects the performance of the water-water heat pump, providing sufficient heating for greenhouse in winter.
INTERNATIONAL JOURNAL OF REFRIGERATION
(2021)
Article
Thermodynamics
Natasa Nord, Mohammad Shakerin, Tymofii Tereshchenko, Vittorio Verda, Romano Borchiellini
Summary: The study focused on developing data-informed physical models for simulating district heating (DH) grids with heat prosumers. Analysis on different configurations revealed pressure imbalances with increased renewable heat share. Variable speed pump control led to significant electricity savings, while lowering temperature levels reduced heat losses in DH networks.
Review
Environmental Sciences
Santanu Malakar, Vinkel Kumar Arora, Prabhat K. Nema, Vikrant Yadav
Summary: The growing demand for solar energy as a replacement for fossil fuels is leading to reduced carbon emissions and global warming. Evacuated tube solar collectors (ETSC) are used in various sectors for air heating, water heating, and drying, and several factors such as fin arrangement, integration of phase change material, and solar radiation influence their performance. This review paper discusses the thermal performance parameters of ETSC-based solar air heaters and dryers, including collector efficiency, dryer efficiency, energy and exergy efficiency, and heat loss during operations. The potential of using solar air heaters (SAH) for food commodity drying is also explored, along with the use of nanofluids and phase change materials to improve thermal performance. Additionally, CO2 mitigation analysis and global standards for ETSC-based air heaters and dryers are compiled.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
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.