Article
Energy & Fuels
Shouying Jin, Binyang Wu, Zhenyuan Zi, Puze Yang, Taifeng Shi, Junhong Zhang
Summary: As the greenhouse effect worsens, ammonia, a carbon-free fuel, is gaining attention. The ammonia-diesel dual-fuel (ADDF) engine can effectively overcome the drawbacks of ammonia's high auto-ignition temperature and slow flame speed, making it an effective solution for reducing greenhouse gas emissions. By studying the effects of ammonia energy ratio (AER) and injection strategy on combustion and emissions, it was found that increasing AER led to a decrease in gross indicated thermal efficiency (ITEg) and an increase in unburned ammonia emissions. Optimizing the injection strategy and combustion process can significantly improve ITEg and reduce greenhouse gas emissions.
Article
Energy & Fuels
Avinash Kumar Agarwal, Akhilendra Pratap Singh, Vikram Kumar
Summary: In this experimental investigation, the effects of different pilot injection techniques on reactivity-controlled compression ignition (RCCI) combustion were explored. The study found that both advanced and retarded start of diesel injection (SoIdiesel) timings resulted in combustion noise and misfire. The use of pilot injection was suitable for the RCCI mode, especially at lower premixed ratios (rp) of methanol. Optimizing the rp of methanol and adopting a suitable injection strategy can significantly improve the combustion, performance, and emissions characteristics of the RCCI mode.
Article
Energy & Fuels
Tie Li, Xinyi Zhou, Ning Wang, Xinran Wang, Run Chen, Shiyan Li, Ping Yi
Summary: Ammonia, as a carbon-free fuel, has great potential for decarbonization in marine engines. The dual-fuel mode can compensate for the poor combustion properties of ammonia. The study shows that in the low-pressure injection dual-fuel mode, the recommended maximum ammonia ratio is about 80% by energy, while the high-pressure injection dual-fuel mode has the potential to achieve a 97% diesel replacement ratio. Compared with the pure diesel mode, the high-pressure injection dual-fuel mode can reduce the equivalent CO2 emissions.
JOURNAL OF THE ENERGY INSTITUTE
(2022)
Article
Energy & Fuels
Ramakrishna Balijepalli, Ankit Kumar, Upendra Rajak, Mohamed Abdelghany Elkotb, Mamdooh Alwetaishi, Siva Kumar Y. Reddy, Abhishek Dasore, Tikendra Nath Verma, C. Ahamed Saleel, Asif Afzal
Summary: The study aimed to increase the combustion efficiency of diesel engine and reduce nitrogen-based emissions by adding natural gas. Findings suggest that optimizing spray angle at 150 degrees can ensure proper combustion with minimum emissions.
Article
Thermodynamics
Jose Antonio Velez Godino, Miguel Torres Garcia, Francisco Jose Jimenez-Espadafor Aguilar
Summary: Experimental study on a compression ignition engine using late direct injection of rapeseed biodiesel fuel blends shows a significant reduction in nitrogen oxides emissions without compromising performance, indicating an advanced combustion mode between traditional compression ignition engines and homogeneous charge compression ignition combustion mode.
Article
Energy & Fuels
Zhongshu Wang, Fangyuan Zhang, Ye Xia, Dan Wang, Yun Xu, Guizhi Du
Summary: This study investigated the impact of pilot diesel injection timing on combustion phases of diesel and natural gas in a dual fuel engine, showing that injection timing plays a crucial role in determining engine thermal efficiency and exhaust emissions level. The results revealed a clear correspondence between the lengths of combustion period of two fuels, with advancing pilot diesel injection resulting in shortened combustion durations and increased combustion overlap periods.
Article
Energy & Fuels
Deqing Mei, Qisong Yu, Zhengjun Zhang, Shan Yue, Lizhi Tu
Summary: The effects of two pilot injections on combustion and emissions in a diesel engine operating in PCCI mode were studied. The results showed that adjusting the timing of pilot injections had significant impacts on pressure, temperature, heat release rate, and NOx generation, with less effect on soot generation. By manipulating the timing and quantity of injections, it is possible to control emissions to some extent.
Article
Multidisciplinary Sciences
Minhoo Choi, Khawar Mohiuddin, Sungwook Park
Summary: The study revealed that increasing the methane mixture ratio in a single cylinder dual-fuel engine led to a transition from diesel combustion to pre-mixed combustion, resulting in reduced nitrogen oxides emissions and increased fuel conversion efficiency. However, this also led to a significant increase in hydrocarbon emissions. The fastest combustion speed was observed with methane mixture ratios between 40% and 80%.
SCIENTIFIC REPORTS
(2021)
Article
Energy & Fuels
Wenhui Tao, Tao Sun, Wenjun Guo, Kangbo Lu, Lei Shi, He Lin
Summary: Diesel fuel pilot injection timing, pilot mass percent, and methanol substitution rate were experimentally investigated to study their effects on the combustion and emissions of a diesel-methanol dual fuel engine. The results showed that adding pilot injection advanced the ignition time and increased the heat release rate. With the increase in pilot mass percent, the peak in-cylinder pressure and heat release rate increased. Furthermore, at high methanol substitution rates, advancing the pilot injection timing, increasing the pilot mass percent, and combining exhaust gas recirculation (EGR) were found to improve combustion performance and reduce emissions.
Article
Energy & Fuels
Xinlei Liu, Hu Wang, Zunqing Zheng, Mingfa Yao
Summary: A comprehensive numerical study on the combustion and emission characteristics of a NG-diesel dual-fuel engine operating at high load conditions was conducted, proposing a pathway to achieve highly efficient and clean combustion. It was found that utilizing at least a 40% EGR rate is necessary to meet NOx Euro VI regulation limits, while other parameters such as injection pressure and nozzle number also play important roles in promoting engine efficiency and reducing emissions.
Article
Thermodynamics
Mahdiar Khosravi, Gordon McTaggart-Cowan, Patrick Kirchen
Summary: This study evaluates the soot formation and oxidation processes in a high-pressure direct injection natural gas engine using pyrometry and chemiluminescence imaging techniques. It finds that fuel injection pressure, injection duration, and relative injection timings significantly influence soot formation and combustion processes.
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2021)
Article
Energy & Fuels
Xichang Wang, Chao Geng, Juntong Dong, Xiaodan Li, Teng Xu, Chao Jin, Haifeng Liu, Bin Mao
Summary: Polyoxymethylene dimethyl ethers (PODE) can enhance the miscibility of ethanol/diesel blends, while the pilot injection strategy can improve combustion noise and NOx emissions. The study shows that optimizing the pilot injection strategy can improve the thermal efficiency and reduce hazardous gas emissions of the blends.
Article
Energy & Fuels
Zhen Gong, Mingda Hu, Yuan Fang, Dong Zhang, Liyan Feng
Summary: Through experimental research, it was found that auto-ignition of lubricating oil can cause pre-ignition, and the burning residuals of oil droplet can act as an ignition source. Two factors, total combustion duration and maximum pressure rise rate (PRRmax), were identified as the main factors influencing the occurrence of LOAP in dual-fuel engines. Adjusting the reagent gas composition and thermodynamic conditions can reduce the total combustion duration and increase PRRmax. The volume of oil droplet has a slight effect on ignition timing but little effect on natural gas pre-ignition. The most influential factors in promoting pre-ignition are ranked as: reagent gases, thermodynamic conditions, and droplet volume.
Article
Thermodynamics
Jisoo Shin, Sungwook Park
Summary: Due to environmental regulations, the use of ammonia as a carbon-free fuel for internal combustion engines is gaining attention. This study investigated the combustion characteristics of an ammonia-diesel dual-fuel engine through numerical simulation. The results showed that advanced injection timing and high ammonia energy fraction can significantly improve efficiency and reduce greenhouse gas emissions.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Article
Energy & Fuels
Hyunwook Park, Euijoon Shim, Junsun Lee, Seungmook Oh, Changup Kim, Yonggyu Lee, Kernyong Kang
Summary: The combination of a double injection strategy and a large-squish piston significantly improved brake thermal efficiency and reduced methane emissions, mainly by improving combustion loss.
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.