Article
Energy & Fuels
Changming Gong, Jingzhen Sun, Yulin Chen, Fenghua Liu
Summary: Numerical simulations showed that a medium compression ratio direct-injection twin-spark plug synchronous ignition engine fueled with methanol had better performance and shorter ignition delay period during cold start compared to a single-spark plug ignition engine. The best cold start compromise was achieved at ignition timing of 21 degrees CA BTDC, injection timing of 70 degrees CA BTDC, and equivalence ratio of 0.9. Twin-spark plug ignition also resulted in lower unburned methanol and soot emissions, but higher NOX emissions at equivalence ratio of 1.0 compared to single-spark plug ignition.
Article
Energy & Fuels
Shuo Zhang, Zhenfeng Zhao, Chuncun Yu, Zhao Geng, Zhenhuan Yang, Shangxue Wang
Summary: This study aims to solve the cold-start problem of heavy fuel piston engines and develop a cold-start control strategy. The experiments show that the engine can start quickly and smoothly within a specific range of control parameters, and the cold-start time and IMEP are most sensitive to the injection advance angle.
Article
Energy & Fuels
Hao Feng, Kaichang Lai, Zunqing Zheng, Sicong Lin, Xiang Wu, Qinglong Tang
Summary: The high octane number and high latent heat of vaporization of methanol are beneficial for suppressing knock and increasing compression ratio in spark ignition engines, leading to improved thermal efficiency. This study investigated the potential of high compression ratio and methanol direct injection (MDI) on the performance of a 1.5-liter spark ignition passenger car engine. The results showed that integrating a high compression ratio of 15.3 and MDI improved brake thermal efficiency (BTE) compared to low CR with gasoline, but also resulted in extended combustion durations and increased THC and CO emissions.
Article
Thermodynamics
M. H. Dinesh, Jayashish Kumar Pandey, G. N. Kumar
Summary: The experimental study showed that using methanol/LPG dual fuel can significantly improve the performance of an SI engine, with increased brake power, brake thermal efficiency, and volumetric efficiency. The flame development period decreases, while the flame propagation period and total combustion duration depend on the compression ratio and LPG fraction.
Article
Energy & Fuels
Fang Liang, Lou Diming, Hu Zhiyuan, Tan Piqiang, Zhang Yunhua, Yang Rong
Summary: Cold-start performance is a significant problem for diesel engines in high-altitude and cold areas. The First-Firing-Cycle (FFC) plays a crucial role in determining cold-start performance, and it is affected by altitude and ambient temperature. Control parameters should take altitude into consideration to improve future cold-start performance.
Article
Chemistry, Applied
Qimeng Duan, Hailiang Kou, Tao Li, Xiaojun Yin, Ke Zeng, Long Wang
Summary: Experimental investigations were conducted to study the effects of intake pressure and injection timing on combustion, performance, and emissions characteristics of a high compression ratio DI SI methanol engine. It was found that retarding injection timing could reduce ignition delay and burn duration, but decreased volumetric efficiency and combustion efficiency. Delaying spark timing could mitigate NO and CO emissions, but led to deterioration in heat release rate, thermal efficiency, and methanol/formaldehyde emissions. Overall, an injection timing range of -270 to -240 degrees CA aTDC would be optimal for good performance.
FUEL PROCESSING TECHNOLOGY
(2023)
Article
Thermodynamics
Binbin Wang, Hechun Wang, Chuanlei Yang, Deng Hu, Baoyin Duan, Yinyan Wang
Summary: This study investigates the impact of diesel-ignited ammonia/methanol engines on combustion and emission performance. It reveals that mixing methanol improves combustion efficiency, reduces ammonia escape, and decreases N2O emissions. The optimal mixing ratio is determined to be 8:2.
APPLIED THERMAL ENGINEERING
(2024)
Article
Energy & Fuels
Jianan Wei, Hongqing Feng, Haifeng Liu, Hongyan Zhu, Zongyu Yue, Mingfa Yao
Summary: The study showed that adding 10% ethanol to iso-octane can accelerate combustion speed with higher heat release rate and pressure rise rate after knocking onset. Additionally, blending methanol with iso-octane enhances knock intensity, particularly at a 30% blend ratio. The new parameter I, measuring the interaction between flame core and pressure wave, revealed that methanol induces more intense knock compared to iso-octane and ethanol.
Article
Energy & Fuels
Haoye Liu, Rafiu Olalere, Chongming Wang, Xiao Ma, Hongming Xu
Summary: 2-Methylfuran (MF) is considered a promising second-generation biofuel for spark ignition engines due to its better anti-knock ability and close lower heating value to conventional fuels. The study investigates the effects of engine control parameters on MF combustion at typical DISI engine operating conditions, showing that MF has a wider achievable spark timing range and more robustness to lean burn compared to gasoline and ethanol at high load. The combustion characteristics and heat release of MF are less sensitive to injection timings variations, but longer injection durations are required compared to gasoline to achieve the same engine load.
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
Thermodynamics
Junhao Qiao, Jingping Liu, Jichao Liang, Dongdong Jia, Rumin Wang, Dazi Shen, Xiongbo Duan
Summary: The novelty of using the asynchronous intake valve in the Miller cycle was proposed and tested in an SI engine. The effects of this novelty on engine performance were analyzed and compared to the results of the Otto cycle. The results showed that the use of the asynchronous intake valve reduced pumping mean effective pressure and increased engine efficiency.
Review
Energy & Fuels
Anh Tuan Hoang, Sandro Nizetic, Van Viet Pham, Anh Tuan Le, Van Ga Bui, Van Vang Le
Summary: This paper discusses the production process and properties of DMF derived from biomass, as well as the oxidation, pyrolysis mechanisms, and combustion characteristics of DMF in engines. DMF could potentially become a fuel for both SI and CI engines, but optimization of the production process is necessary before application.
Article
Energy & Fuels
Lker Ors, Savas Yelbey, Halil Erdi Gulcan, Bahar Sayin Kul, Murat Ciniviz
Summary: This study analyzes the combustion behavior of an SI engine and evaluates its thermodynamic performance through energy and exergy analysis. The addition of small amounts of ethanol and methanol to gasoline is compared with gasoline as the reference fuel. The study demonstrates that the addition of ethanol and methanol increases the maximum in-cylinder pressure, while reducing the average in-cylinder gas temperature and increasing the pressure increase rates. The volumetric addition of ethanol/methanol to gasoline has a decreasing effect on thermal and exergetic efficiency values.
Article
Chemistry, Multidisciplinary
Adrian Irimescu, Simona Silvia Merola, Bianca Maria Vaglieco
Summary: Spark ignition (SI) engines are commonly used for distributed power generation applications, providing quick deployment and cost-effective electricity. Fixed ignition timing is often employed for small size engines, utilizing wasted spark systems with two spark events per cycle. However, more complex control systems are being applied to improve efficiency and reduce emissions. This study proposes a method for identifying top dead center (TDC) phasing in real-time using current measurements in the secondary ignition circuit. The algorithm was tested on a 50 cm^3 SI unit connected to a 1 kW power generator, achieving a TDC identification success rate over 99.8%.
APPLIED SCIENCES-BASEL
(2023)
Article
Chemistry, Applied
Suleyman Simsek, Samet Uslu, Hatice Simsek, Gonca Uslu
Summary: The study aimed to optimize the use of liquefied petroleum gas (LPG) in gasoline-LPG blends for an SI engine, focusing on performance and emissions. Response surface methodology (RSM) was utilized to determine the optimal LPG ratio, with findings showing significant effects on various responses, particularly BSFC and BTE. Verification study revealed low error rates in modeling the SI engine with RSM.
FUEL PROCESSING TECHNOLOGY
(2021)
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.