Article
Thermodynamics
Eshan Singh, David Vuilleumier, Namho Kim, Magnus Sjoberg
Summary: Mixed-Mode Combustion (MMC) is a method to improve the efficiency of stoichiometric spark-ignition engines by using a lean working fluid and controlled end-gas autoignition. This study investigated the effects of intake conditions and residual gas composition on the autoignition tendency of different fuels, and obtained the applicable conditions and requirements for different fuels.
COMBUSTION AND FLAME
(2022)
Article
Chemistry, Physical
Gu Xin, Changwei Ji, Shuofeng Wang, Hao Meng, Ke Chang, Jinxin Yang
Summary: This experimental study investigates the suppression of heat release rate in a hydrogen-fueled engine through the addition of ammonia. The results show that adding small amounts of ammonia decreases the combustion rate, prolongs flame development and propagation durations, reduces pressure and heat release rate peaks, and increases peak effective pressure and thermal efficiency. However, it also leads to increased nitrogen oxide emissions.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Thermodynamics
Xue-Qing Fu, Bang-Quan He, Si-Peng Xu, Tao Chen, Hua Zhao, Yan Zhang, Yufeng Li, Honglin Bai
Summary: Lean-burn combustion is effective in reducing fuel consumption of gasoline engines, but faces challenges such as unstable ignition and high emissions. Multi-point micro-flame-ignited hybrid combustion can extend the lean burn limit and improve thermal efficiency.
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2021)
Article
Thermodynamics
Mortadha K. Mohammed, Hyder H. Balla, Zaid Maan H. Al-Dulaimi, Zaid S. Kareem, Mudhaffar S. Al-Zuhairy
Summary: The negative effects of traditional engine fuels on climate change have led to a high level of competition in finding alternative fuels that are more environmentally friendly. Alcohol fuels, particularly ethanol, have been found to be practical for blending with traditional engine fuels like gasoline. Research has shown that blending ethanol with gasoline can increase power, efficiency, and reduce harmful exhaust gases. However, ethanol may have a negative impact on volumetric efficiency, while also improving power and efficiency as its concentration increases.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Energy & Fuels
Changzhao Jiang, Chongming Wang, Hongming Xu, Haoye Liu, Xiao Ma
Summary: The study found that employing the stratified lean-burn mode in spark-ignition engines can significantly improve fuel economy, with up to a 16% increase if the second injection timing is optimized. The second injection timing also has significant impacts on IMEP, combustion duration, COV, gaseous emission, and particulate number emissions.
Article
Energy & Fuels
You Zhou, Wei Hong, Fangxi Xie, Yan Su, Zhongshu Wang, Yu Liu
Summary: In order to address the energy and environmental issues, the development of new technologies and alternative fuels has gained attention. This study investigated the impact of different valve lift adjustment strategies on engine performance when fueled with methanol/gasoline blending. The results showed that adjusting intake and exhaust valve lifts could improve economy performance and reduce emissions. The optimal valve strategy varied depending on the fuel composition. The blending of methanol with gasoline extended the lean burn limit and further improved engine performance.
Article
Engineering, Chemical
Mahdi Aghahasani, Ayat Gharehghani, Amin Mahmoudzadeh Andwari, Maciej Mikulski, Apostolos Pesyridis, Thanos Megaritis, Juho Konno
Summary: This study investigates the effects of hydrogen direct injection with different hydrogen energy shares (HES) on the performance and emissions characteristics of a gasoline port-injection SI engine using reactive computational fluid dynamics. Results show that different injection timings and HES can significantly impact NOX, HC, soot, CO, CO2, and particulate matter emissions.
Article
Chemistry, Physical
Devunuri Suresh, Ekambaram Porpatham
Summary: This paper investigates the effects of ethanol-gasoline-hydrogen blends with different proportions in a lean-burn SI engine. The results show that the E10 blend is optimal, and the addition of ethanol enhances brake power and efficiency. Further, adding hydrogen to the E10 mixture significantly improves the combustion process and reduces emissions. The study also finds that the lean limit is extended with ethanol compared to pure gasoline.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Thermodynamics
Qimeng Duan, Tao Li, Dong Liu, Xiaojun Yin, Ke Zeng, Long Wang
Summary: The study demonstrates that using multiple-injection strategies can improve the combustion efficiency and stability of methanol engines, while reducing cycle-to-cycle variations. In experimental evaluations, the triple-injection strategy shows superior performance, especially in terms of thermal efficiency and nitrogen oxide emissions.
APPLIED THERMAL ENGINEERING
(2024)
Article
Chemistry, Physical
Jianbing Gao, Guohong Tian, Chaochen Ma, Yuanjian Zhang, Shikai Xing, Phil Jenner
Summary: Lean-burn was adopted as an effective method in this study to reduce NOx emissions from hydrogen combustion in ORP engines. The equivalence ratio has a significant impact on combustion and NOx emission characteristics, with effects varying with engine speeds. High NOx emissions were observed under low engine speed conditions due to hydrogen combustion near stoichiometric ratio.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Energy & Fuels
Aneesh Vijay Kale, Anand Krishnasamy
Summary: Recent research has shown that homogeneous charge compression ignition (HCCI) engines can enhance traditional compression-ignition engines. Gasoline-like fuels with higher octane number and vapor pressure are better suited for port fuel-injected HCCI engines. By adding ignition promoters, intake charge preheating or turbocharging requirements can be eliminated, and cyclic variations in combustion can be reduced. Suitable diluents can prevent knocking and enable higher load extension. This study investigated various ignition promoters and diluents to achieve constant combustion phasing in gasoline-fueled HCCI combustion.
Article
Energy & Fuels
Ze Liu, Xiumin Yu, Ping Sun, Sichuan Xu
Summary: The study aims to improve the performance of gasoline SI engines under lean burn conditions through dual-injection mode GPI + NDI, leading to increased efficiency and reduced emissions. The GPI + NDI mode achieves stable combustion at lambda = 1.4, broadening the lean burn limit of the gasoline engine at low load.
Article
Energy & Fuels
Xinlei Liu, Hammam Aljabri, Mickael Silva, Abdullah S. AlRamadan, Moez Ben Houidi, Emre Cenker, Hong G. Im
Summary: The combustion of hydrogen in engines produces few harmful emissions, with the exception of nitric oxides (NOx), which can be reduced under lean-burn conditions. This study investigated the feasibility of hydrogen pre-chamber combustion in a heavy-duty diesel engine using CFD modeling. The results showed that the pre-chamber combustion effectively controlled heat release and reduced NOx emissions, but also decreased complete combustion and combustion stability. The engine operating range could be extended by introducing fuel into the pre-chamber and adjusting the pre-chamber throat diameter to control the pressure rise rate.
Article
Engineering, Aerospace
Ufaith Qadiri, D. Siva Krishna Reddy, Amjad Ali Pasha, Mohammad Irfan Alam
Summary: This research work applies novel state-of-the-art technology on a multi-cylinder SI engine fueled by compressed natural gas, emulsified fuel, and hydrogen as dual fuel. It predicts the performance, combustion, and exhaust emissions of these fuels using simulation technology. The results show that hydrogen has higher brake power and lower fuel consumption compared to CNG and emulsified fuel. Additionally, all the alternative fuels lead to improved emissions compared to traditional fuels, with hydrogen producing zero CO and HC emissions.
CHINESE JOURNAL OF AERONAUTICS
(2023)
Article
Chemistry, Multidisciplinary
Xuejiao Dai, Aqian Li, Zhaolei Zheng
Summary: In this study, numerical simulation is used to investigate the effects of different water injection pressures on knock combustion of turbocharged direct injection gasoline engines. The results show that direct water injection significantly reduces knock intensity, with complete suppression observed at water injection pressures above 40 bar. The study also explores the impacts of water injection pressure on water evaporation, in-cylinder combustion, and the knocking mechanism.
Article
Thermodynamics
Qi Liu, Tao Guo, Jianqin Fu, Hongliang Dai, Jingping Liu
Summary: Injection pressure has significant effect on emissions, while injection timing influences maximum combustion pressure, and a lower EGR rate of 7% reduces NOx emissions significantly, improving overall ACE performance.
Article
Chemistry, Physical
Yaorui Shen, Mingke Xie, Xiaoqi Wu, Jingping Liu, Huanhuan Bao, Jianqin Fu
Summary: This study investigated the effects of CO2/H2O dilution on the ignition delay time (IDT) of methane under different conditions using sensitivity analysis, mole fraction analysis, and reaction path analysis. The results showed that the IDT increases with increasing CO2/H2O ratios at high temperatures. At an equivalence ratio of 2.0 and low to medium temperatures, the diluent gas with a CO2/H2O ratio of 0.4/0.6 had the strongest suppression effect on methane ignition.
INTERNATIONAL JOURNAL OF CHEMICAL KINETICS
(2022)
Article
Environmental Sciences
Mingke Xie, Qingyu Li, Jianqin Fu, Huiyong Yang, Xun Wang, Jinping Liu
Summary: This study investigates the NOx formation mechanism and the influence of parameters in ethanol-gasoline blends used in a GDI SI engine through experiments and chemical kinetic simulation. The results show that in addition to the thermal pathway, pathways involving N2O and NNH have a significant impact on NOx emissions under high engine speed conditions. Initial temperature exacerbates NOx emissions, while initial pressure and ethanol fraction inhibit it. The equivalence ratio (ER) initially promotes NOx formation, but then resists it, with the highest emission occurring at an ER of 0.85. In lean burn conditions, the thermal pathway is highly inhibited, while the N2O pathway is accelerated.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Engineering, Chemical
Huiyong Yang, Xun Wang, Jianqin Fu, Jingping Liu
Summary: This study investigates the influence of CO2 and H2O as diluents on laminar burning velocity (LBV) of CH4/air/CO2/H2O mixtures. The chemical effects of CO2 and H2O were separated using a decoupling method. The results show that the initial temperature promotes the chemical effects, while the initial pressure has the opposite effect. The inhibiting effect of CO2 on LBV is stronger than that of H2O. Furthermore, the chemical effects of adding CO2 and H2O separately are greater than adding equal amounts of CO2 and H2O simultaneously.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2023)
Review
Chemistry, Physical
Xun Wang, Jianqin Fu, Zhen Liu, Jingping Liu
Summary: Hydrogen has garnered significant attention as a clean energy source due to its high thermal conversion efficiency, recyclability, and non-polluting properties. The increasing number of hydrogen fuel cell vehicles and refueling stations globally underscores their research prominence. However, the rapid increase in internal temperature caused by high-pressure hydrogen filling poses a major challenge. This review systematically elucidates the temperature rise principle, summarizes the impact of refueling parameters on tank state, and proposes mitigation measures and solutions to limit or mitigate temperature rise effects, such as pre-cooling hydrogen, reducing initial hydrogen content, and maintaining low ambient and initial tank temperatures. Furthermore, safe refueling strategies and methods are presented. The comprehensive study in this paper refines the crucial relationship between refueling parameters and tank temperature rise, providing valuable insights for advancing new refueling strategies and hydrogen fuel cell vehicles.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Thermodynamics
Shuo Yuan, Wenbin Lei, Qi Liu, Runze Liu, Jingping Liu, Jianqin Fu, Yubo Han
Summary: This study predicts the potential distribution of global microalgae biomass energy using a mathematical model and provides reference for the development and site selection of microalgal biomass energy. The global potential biomass is estimated to be substantial, indicating its significant energy value.
Article
Thermodynamics
Renhua Feng, Guanghua Li, Zhengwei Sun, Xiulin Hu, Banglin Deng, Jianqin Fu
Summary: In this study, a non-road diesel engine was tested under different operating conditions, and improvement measures were applied to optimize the engine and reduce emissions. The results showed significant reduction in particulate matter emissions at medium-high speed and low load, but higher nitrogen oxide emissions under low load conditions. However, at medium-high speed and load, nitrogen oxide emissions were reduced. Unburned hydrocarbon and carbon monoxide emissions were maintained at extremely low levels, and fuel consumption remained constant under all operating conditions.
Article
Thermodynamics
Qi Liu, Jianqin Fu, Jingping Liu, Huiyong Yang
Summary: This study conducted sweeping tests on a heavy-duty truck liquid methane engine to investigate the combustion characteristics under different compression ratios, ignition timing, and hydrogen addition. The results showed that compression ratio had minimal impact on ignition delay, while ignition timing and hydrogen addition significantly affected the start of combustion. Increasing hydrogen addition reduced ignition delay and elongated the CA50-90 stage, leading to improved combustion performance.
INTERNATIONAL JOURNAL OF GREEN ENERGY
(2023)
Article
Thermodynamics
Mingke Xie, Jianqin Fu, Cheng Sun, Xilei Sun, Jingping Liu
Summary: Researching the combustion instability of ACE is important for both HEV development and combustion control of the Atkinson cycle. Sweeping tests are conducted on a gasoline ACE with EGR, and thermodynamics time series are obtained. Analysis methods like PSR, RP, and RQA are employed to study the chaotic characteristics and combustion instability. The influence of EGR on ACE combustion instability is studied, and new quantitative indicators are proposed to quantify fluctuation property.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Xilei Sun, Jianqin Fu, Huiyong Yang, Mingke Xie, Jingping Liu
Summary: To effectively manage the energy of plug-in hybrid electric vehicles (PHEVs), an energy management strategy (EMS) based on deep learning and improved model predictive control was proposed. Various prediction models were compared and analyzed, and a long short-term memory based improved model predictive control algorithm (LSTM-IMPC) was developed. The results show that the LSTM-IMPC-based EMS has a significant fuel-saving performance and robustness, with fuel-saving rates close to the global optimal solution.
Article
Energy & Fuels
Xilei Sun, Mingke Xie, Feng Zhou, Jianqin Fu, Jingping Liu
Summary: This study investigates the effects of injection timing, injection pressure, and exhaust gas recirculation (EGR) rate on the combustion, thermodynamic, and emission characteristics of the Atkinson cycle engine (ACE), and performs multi-objective optimization to improve overall performance. Experimental tests were conducted, and machine learning models (CART, RF, AdaBoost) were developed to analyze the data and make predictions. The multi-objective optimization using the AdaBoost model and NSGA II algorithm successfully reduces CO, BSFC, NOx, and PN emissions.
Article
Energy & Fuels
Renhua Feng, Xiulin Hu, Guanghua Li, Banglin Deng
Summary: In this paper, the emission characteristics and catalytic reactors interactions of a non-road diesel engine are studied under non-road transient cycle (NRTC) through experiment and simulation. The results show high emission conversion efficiencies for HC, CO, NOX, and PM. The interactions of each catalytic converter are obtained, revealing the effectiveness of DOC in reducing CO and HC emissions and converting NO to NO2. The SCR and ASC also contribute to NOx reduction, and the DPF plays a crucial role in PM collection and oxidation.
Article
Chemistry, Applied
Xun Wang, Feng Zhou, Jianqin Fu, Jingping Liu
Summary: The study of the theory of multi-fuel mixed combustion is crucial for improving power machines. Adding ethanol to gasoline accelerates its combustion process, and the maximum pressure of ethanol-gasoline mixtures increases with higher ethanol ratio and initial temperature, while decreases with higher initial pressure. Ethanol addition also increases the production of intermediates and reactive radicals in the system, promoting the design of ethanol-gasoline power engines and the development of alternative fuels.
FUEL PROCESSING TECHNOLOGY
(2023)
Article
Green & Sustainable Science & Technology
Renhua Feng, Guanghua Li, Zhichao Zhao, Banglin Deng, Xiulin Hu, Jianxiong Liu, Shaoyang Wang
Summary: Energy flow analysis is an effective method for assessing and improving vehicle efficiency. In this study, an energy flow experiment of a series-parallel hybrid electric vehicle (HEV) is conducted, and two optimized control strategies are employed to reduce fuel consumption. The results show that the fuel consumption is reduced by 7.1% to 7.5% compared to the original vehicle.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Thermodynamics
Yong Cheng, Fukai Song, Lei Fu, Saishuai Dai, Zhiming Yuan, Atilla Incecik
Summary: This paper investigates the accessibility of wave energy absorption by a dual-pontoon floating breakwater integrated with hybrid-type wave energy converters (WECs) and proposes a hydraulic-pneumatic complementary energy extraction method. The performance of the system is validated through experiments and comparative analysis.
Article
Thermodynamics
Jing Gao, Chao Wang, Zhanwu Wang, Jin Lin, Runkai Zhang, Xin Wu, Guangyin Xu, Zhenfeng Wang
Summary: This study aims to establish a new integrated method for biomass cogeneration project site selection, with a focus on the application of the model in Henan Province. By integrating Geographic Information System and Multiple Criterion Decision Making methods, the study conducts site selection in two stages, providing a theoretical reference for the construction of biomass cogeneration projects.
Article
Thermodynamics
Mert Temiz, Ibrahim Dincer
Summary: The current study presents a hybrid small modular nuclear reactor and solar-based system for sustainable communities, integrating floating and bifacial photovoltaic arrays with a small modular reactor. The system efficiently generates power, hydrogen, ammonia, freshwater, and heat for residential, agricultural, and aquaculture facilities. Thermodynamic analysis shows high energy and exergy efficiencies, as well as large-scale ammonia production meeting the needs of metropolitan areas. The hybridization of nuclear and solar technologies offers advantages of reliability, environmental friendliness, and cost efficiency compared to renewable-alone and fossil-based systems.
Editorial Material
Thermodynamics
Wojciech Stanek, Wojciech Adamczyk
Article
Thermodynamics
Desheng Xu, Yanfeng Li, Tianmei Du, Hua Zhong, Youbo Huang, Lei Li, Xiangling Duanmu
Summary: This study investigates the optimization of hybrid mechanical-natural ventilation for smoke control in complex metro stations. The results show that atrium fires are more significantly impacted by outdoor temperature variations compared to concourse/platform fires. The gathered high-temperature smoke inside the atrium can reach up to 900 K under a 5 MW train fire energy release. The findings provide crucial engineering insights into integrating weather data and adaptable ventilation protocols for smoke prevention/mitigation.
Article
Thermodynamics
Da Guo, Heping Xie, Mingzhong Gao, Jianan Li, Zhiqiang He, Ling Chen, Cong Li, Le Zhao, Dingming Wang, Yiwei Zhang, Xin Fang, Guikang Liu, Zhongya Zhou, Lin Dai
Summary: This study proposes a new in-situ pressure-preserved coring tool and elaborates its pressure-preserving mechanism. The experimental and field test results demonstrate that this tool has a high pressure-preservation capability and can maintain a stable pressure in deep wells. This study provides a theoretical framework and design standards for the development of similar technologies.
Article
Thermodynamics
Aolin Lai, Qunwei Wang
Summary: This study assesses the impact of China's de-capacity policy on renewable energy development efficiency (REDE) using the Global-MSBM model and the difference-in-differences method. The findings indicate that the policy significantly enhances REDE, promoting technological advancements and marketization. Moreover, regions with stricter environmental regulations experience a higher impact.
Article
Thermodynamics
Mostafa Ghasemi, Hegazy Rezk
Summary: This study utilizes fuzzy modeling and optimization to enhance the performance of microbial fuel cells (MFCs). By simulating and analyzing experimental data sets, the ideal parameter values for increasing power density, COD elimination, and coulombic efficiency were determined. The results demonstrate that the fuzzy model and optimization methods can significantly improve the performance of MFCs.
Article
Thermodynamics
Zhang Ruan, Lianzhong Huang, Kai Wang, Ranqi Ma, Zhongyi Wang, Rui Zhang, Haoyang Zhao, Cong Wang
Summary: This paper proposes a grey box model for fuel consumption prediction of wing-diesel hybrid vessels based on feature construction. By using both parallel and series grey box modeling methods and six machine learning algorithms, twelve combinations of prediction models are established. A feature construction method based on the aerodynamic performance of the wing and the energy relationship of the hybrid system is introduced. The best combination is obtained by considering the root mean square error, and it shows improved accuracy compared to the white box model. The proposed grey box model can accurately predict the daily fuel consumption of wing-diesel hybrid vessels, contributing to operational optimization and the greenization and decarbonization of the shipping industry.
Article
Thermodynamics
Huayi Chang, Nico Heerink, Junbiao Zhang, Ke He
Summary: This study examines the interaction between off-farm employment decisions between couples and household clean energy consumption in rural China, and finds that two-paycheck households are more likely to consume clean energy. The off-farm employment of women is a key factor driving household clean energy consumption to a higher level, with wage-employed wives having a stronger influence on these decisions than self-employed ones.
Article
Thermodynamics
Hanguan Wen, Xiufeng Liu, Ming Yang, Bo Lei, Xu Cheng, Zhe Chen
Summary: Demand-side management is crucial to smart energy systems. This paper proposes a data-driven approach to understand the relationship between energy consumption patterns and household characteristics for better DSM services. The proposed method uses a clustering algorithm to generate optimal customer groups for DSM and a deep learning model for training. The model can predict the possibility of DSM membership for a given household. The results demonstrate the usefulness of weekly energy consumption data and household socio-demographic information for distinguishing consumer groups and the potential for targeted DSM strategies.
Article
Thermodynamics
Xinglan Hou, Xiuping Zhong, Shuaishuai Nie, Yafei Wang, Guigang Tu, Yingrui Ma, Kunyan Liu, Chen Chen
Summary: This study explores the feasibility of utilizing a multi-level horizontal branch well heat recovery system in the Qiabuqia geothermal field. The research systematically investigates the effects of various engineering parameters on production temperature, establishes mathematical models to describe their relationships, and evaluates the economic viability of the system. The findings demonstrate the significant economic feasibility of the multi-level branch well system.
Article
Thermodynamics
Longxin Zhang, Songtao Wang, Site Hu
Summary: This investigation reveals the influence of tip leakage flow on the modern transonic rotor and finds that the increase of tip clearance size leads to a decline in rotor performance. However, an optimal tip clearance size can extend the rotor's stall margin.
Article
Thermodynamics
Kristian Gjoka, Behzad Rismanchi, Robert H. Crawford
Summary: This paper proposes a framework for assessing the performance of 5GDHC systems and demonstrates it through a case study in a university campus in Melbourne, Australia. The results show that 5GDHC systems are a cost-effective and environmentally viable solution in mild climates, and their successful implementation in Australia can create new market opportunities and potential adoption in other countries with similar climatic conditions.
Article
Thermodynamics
Jianwei Li, Guotai Wang, Panpan Yang, Yongshuang Wen, Leian Zhang, Rujun Song, Chengwei Hou
Summary: This study proposes an orientation-adaptive electromagnetic energy harvester by introducing a rotatable bluff body, which allows for self-regulation to cater for changing wind flow direction. Experimental results show that the output power of the energy harvester can be greatly enhanced with increased rotatory inertia of the rotating bluff body, providing a promising solution for harnessing wind-induced vibration energy.
