Article
Thermodynamics
Yan Hua, Zhong Wang, Ruina Li, Shuai Liu, Yang Zhao, Lei Qu, Deqing Mei, Hui Lv
Summary: This study investigated the morphology, nanostructure, and oxidation reactivity of particles produced by the combustion of Fischer-Tropsch (F-T) diesel, biodiesel, and regular diesel through techniques such as HRTEM, RS, and TGA. The results showed that F-T diesel particles had smaller fractal dimension and fringe tortuosity, higher graphitization degree, and lower oxidation reactivity compared to regular diesel particles. Biodiesel particles exhibited the opposite characteristics and were more prone to oxidation. The application of exhaust gas recirculation (EGR) increased particle agglomeration, reduced graphitization degree and oxidation characteristic temperature, and enhanced particle oxidation reactivity.
Article
Environmental Sciences
Yachao Wang, Sheng Su, Yitu Lai, Wanyou Luo, Pan Hou, Tao Lyu, Yunshan Ge
Summary: Particles larger than 10 nm from engine exhaust are causing global concerns. This study investigated the impact of EGR on SPN10 (solid particles larger than 10 nm) emissions from gasoline vehicles. The results showed that vehicles with EGR were more likely to exceed the current limit if the cut-off size was reduced to 10 nm. Specifically, during the WLTC test, EGR increased SPN10 emission factors by 2-3 times depending on vehicle powertrains. Notably, active engagement of EGR resulted in a significant increase in SPN10 emissions, while a constant EGR rate led to a decrease. EGR and enriched fuel-air mixture were identified as critical factors contributing to the increased SPN10 emissions.
ENVIRONMENT INTERNATIONAL
(2023)
Article
Thermodynamics
G. D. Telli, G. Y. Zulian, T. D. M. Lanzanova, M. E. S. Martins, L. A. O. Rocha
Summary: Homogeneous charge compression ignition (HCCI), also known as Controlled Auto-Ignition (CAI), enables combustion with high fuel conversion efficiency and low NOX emissions. Water injection was used for combustion phasing control and load expansion in an ethanol HCCI engine, achieving significant improvements in maximum operational load and combustion efficiency.
APPLIED THERMAL ENGINEERING
(2022)
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
Thermodynamics
Somyeh Parsa, Elaheh Neshat
Summary: The study investigates the effect of exhaust gas recirculation technology on waste heat recovery from homogeneous charge compression ignition engines. It shows that lower contents of exhaust gas result in higher recoverable energy, increased engine output works, and higher efficiencies.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Energy & Fuels
Changming Gong, Xiankai Si, Yang Wang, Fenghua Liu
Summary: The experimental results indicate that the addition of CO2 in the intake charge of a GDI engine has a positive effect on combustion performance and emissions compared to adding EGR, with a more significant impact at low loads.
Article
Energy & Fuels
Jichao Liang, Quanchang Zhang, Zheng Chen, Zunqing Zheng, Chao Yang, Qixin Ma
Summary: The use of Tetrahydrofuran (THF) and ethanol as co-solvents for diesel fuel can increase combustion efficiency and reduce emissions, especially at low EGR rates, in diesel engine tests.
Article
Thermodynamics
M. M. Hasan, M. M. Rahman, M. G. Rasul
Summary: The study numerically investigated the thermal and auto-ignition performance of a HCCI engine fueled with diethyl ether and ethanol blends, showing that increasing ethanol proportion delayed combustion start and improved thermal efficiency.
APPLIED THERMAL ENGINEERING
(2021)
Article
Energy & Fuels
Aneesh Vijay Kale, Anand Krishnasamy
Summary: This study aims to extend the operating load range of a diesel engine in HCCI mode by using high volatile, optimum reactivity fuel. The results show that increasing the content of diisopropyl ether in fuel blends can improve the indicated thermal efficiency, but also increase the emissions of unburned hydrocarbon and carbon monoxide.
Article
Thermodynamics
Akihiro Takeshita, Yudai Yamasaki, Mitsuhiro Muto, Takayuki Hikita, Takuma Fujii, Saori Mizuno
Summary: This study developed a model for the gas exchange process in a rebreathing HCCI engine by combining discrete and continuous models to reduce computational load while maintaining prediction accuracy, confirming that the model's calculations were about half the time of one cycle and had a maximum error of about 10% compared to 1D engine simulation software results.
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2022)
Article
Energy & Fuels
Linghai Han, Jiaquan Duan, Dingchao Qian, Yanfeng Gong, Yaodong Wang, Fangxi Xie, Yan Su
Summary: The thermal efficiency of gasoline engines is only about 40% and they produce harmful emissions. In order to comply with low-carbon development and compete with electric vehicles, automobile engines need to reduce fuel consumption and emissions. Homogeneous charge compression ignition (HCCI) combustion combined with variable valve actuation (VVA) technology is an important way to improve engine emissions and economy. However, existing VVA mechanisms have poor valve response, so a cam driven hydraulic variable valve actuation (CDH-VVA) mechanism was designed to solve this problem. The CDH-VVA mechanism has fast valve response characteristics and can also form intake port exhaust gas recirculation (EGR).
Article
Environmental Studies
Yuzhe Zhao, Yujun Fan, Kjetil Fagerholt, Jingmiao Zhou
Summary: This study develops a model to analyze and select emission reduction technologies for ships. The results show that installing EGR without scrubbers is the optimal choice for risk-averse shipowners. Additionally, expanding the ban on open-loop scrubbers within territorial waters has minimal impact on technology choices for feeder services.
TRANSPORTATION RESEARCH PART D-TRANSPORT AND ENVIRONMENT
(2021)
Article
Thermodynamics
Aneesh Vijay Kale, Anand Krishnasamy
Summary: Reactivity controlled compression ignition (RCCI) and homogeneous charge compression ignition (HCCI) are alternative combustion strategies to improve diesel engine performance and reduce emissions. This study focused on using low reactivity, high volatile methanol-gasoline blends in HCCI engines and found that varying fuel composition is more effective than varying exhaust gas recirculation rate in improving efficiency and reducing emissions. Additionally, HCCI outperformed RCCI at mid to higher loads.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Article
Thermodynamics
Dominic Parsons, Simon Orchard, Nick Evans, Umud Ozturk, Richard Burke, Chris Brace
Summary: Exhaust gas recirculation (EGR) technology is crucial for controlling knock and improving efficiency. However, there is limited research on the impact of EGR gas source on EGR performance. This paper demonstrates a novel method to compare the effect of EGR catalysis on knock onset angle in an engine.
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2021)
Article
Energy & Fuels
Tanmay Kar, Toluwalase Fosudo, Anthony Marchese, Bret Windom, Daniel Olsen
Summary: This study investigates the effects of different LPG fuels and exhaust gas recirculation (EGR) on a spark-ignited cooperative fuel research (CFR) engine through experimental and numerical analysis. Results show that fuel composition has a significant impact on engine combustion characteristics, and the introduction of EGR helps reduce knock intensity.
Article
Chemistry, Multidisciplinary
Ahyun Ko, Youngmin Woo, Jinyoung Jang, Yongjin Jung, Youngdug Pyo, Hyun Jo, Ocktaeck Lim, Young Jae Lee
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2019)
Article
Energy & Fuels
Nguyen Xuan Khoa, Ocktaeck Lim
Article
Energy & Fuels
Bambang Wahono, Ardhika Setiawan, Ocktaeck Lim
Review
Energy & Fuels
Nguyen Ba Hung, Ocktaeck Lim
Article
Thermodynamics
Hyunwook Park, Junsun Lee, Narankhuu Jamsran, Seungmook Oh, Changup Kim, Yonggyu Lee, Kernyong Kang
Summary: Synthesis gas (syngas) serves as an intermediary fuel source between traditional carbon-based fuels and hydrogen-based fuels. The comparison between stoichiometric and lean combustion modes in a single-cylinder SI engine reveals the optimal combustion mode for a syngas engine generator. The study highlights the importance of optimizing factors such as compression ratio and intake boosting for improved engine performance. However, differences in power output and thermal efficiency exist between the two combustion modes, emphasizing trade-offs in engine design.
ENERGY CONVERSION AND MANAGEMENT
(2021)
Article
Energy & Fuels
Narankhuu Jamsran, Hyunwook Park, Junsun Lee, Seungmook Oh, Changup Kim, Yonggyu Lee, Kernyong Kang
Summary: HCCI combustion with different syngas compositions was studied, showing that higher H2 content in the fuel can facilitate fast burning and good combustion stability. The NOx emissions were very low due to the ultra-lean, diluted charge used for HCCI combustion.
Article
Engineering, Mechanical
Nguyen Ba Hung, Le Anh Tuan, Ocktaeck Lim
Summary: This study analyzes the operating characteristics of a gaseous fuel injection system for CNG fueled vehicles, focusing on the effects of changing parameters of the electric pressure regulator on the controlled gas pressure in the rail tube. The simulation results show that adjustments in coil resistance, inlet gas pressure, and set pressure can significantly impact the stability of the injection flow rate.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART D-JOURNAL OF AUTOMOBILE ENGINEERING
(2022)
Review
Chemistry, Multidisciplinary
Yanuandri Putrasari, Ocktaeck Lim
Summary: DME, a new generation fuel derived from natural gas and coal, can be used in conventional internal combustion engines without major modifications. Its main advantage lies in lower NOx and particulate emissions compared to fossil liquid fuels, offering potential improvements in engine efficiency and emissions reduction with minimal effort.
Article
Chemistry, Multidisciplinary
Nguyen Xuan Khoa, Ocktaeck Lim
Summary: In this research, the effects of combustion duration on the performance and emissions of a spark-ignition engine using methanol and ethanol fuels were estimated and summarized. The results showed that increasing combustion duration leads to a decrease in peak firing temperature and pressure, and an increase in trapped residual gas. The level of trapped residual gas is higher with ethanol fuel compared to methanol fuel. The indicated mean effective pressure and brake mean effective pressure initially increase and then decrease with increasing combustion duration, while the brake specific fuel consumption reaches a minimum and then increases. The optimal brake specific fuel consumption improved by 33.31% when ethanol fuel was used instead of methanol. Increasing combustion duration helps reduce NOx and HC emissions, but leads to an increase in CO emissions.
Article
Energy & Fuels
Narankhuu Jamsran, Hyunwook Park, Junsun Lee, Seungmook Oh, Changup Kim, Yonggyu Lee, Kernyong Kang
Summary: This study experimentally investigated the effects of various syngas compositions on combustion and emissions of a homogeneous charge compression ignition (HCCI) engine. The results showed that a syngas composition with high H2 content and low CO content was favorable for improving thermal efficiency and load extension of the engine.
Review
Chemistry, Physical
Muhammad Khristamto Aditya Wardana, Ocktaeck Lim
Summary: Diesel engines are widely used in commercial vehicles, but they emit harmful nitrogen oxides (NOx). Reducing NOx emissions is challenging due to issues such as solidification of urea particles, difficulty in spraying small urea particles, adherence of larger urea particles, and difficulty in evaporating urea droplets. Different treatments are used in light-duty, medium-duty, heavy-duty, and marine diesel engines to optimize the NOx conversion in the selective catalytic reduction system. This review analyzes studies aimed at increasing NOx conversion in various diesel engine types, providing a suitable starting point for future research.
Article
Energy & Fuels
Kyeonghun Jwa, Ardhika Setiawan, Ocktaeck Lim
Summary: This experimental study investigated the effect of fuel injection pressure and timing of the second start of injection (SOI2) on combustion and emission characteristics using a single-cylinder compression ignition (CI) engine with a pilot injection strategy. The results showed that increasing fuel injection pressure led to a longer ignition delay, while closer injection timing to TDC inhibited spray penetration. Additionally, 700-bar injection pressure resulted in the lowest CO2 emissions and the longest ignition delay. NOx emissions were identified as indicators of high temperature during combustion. Earlier injection timings initiated low thermal reaction (LTR) conditions, causing a temperature decrease during combustion due to incomplete combustion and fuel deposits in the cylinder vicinity.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2023)
Article
Thermodynamics
Nguyen Ba Hung, Ocktaeck Lim
Summary: A study was conducted to investigate the impact of design parameters on the operational performance of a compressed natural gas (CNG) injection system. Mathematical models were developed to depict the functioning of the system, including electrical and mechanical models for the solenoid pressure regulator and injector. A control model was implemented using proportional integral derivative (PID) algorithm to regulate rail tube gas pressure. Simulation results were compared with experimental data to validate the mathematical models. The study examined the effects of design parameters, such as rail tube volume, spring stiffness, and coil turns in the solenoid pressure regulator, on the performance of the CNG system. The results revealed that increasing rail tube volume and spring stiffness enhanced the stability of controlled gas pressure, while decreasing the coil turns in the solenoid pressure regulator improved the stability of both gas pressure and injection flow rate.
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2023)
Article
Green & Sustainable Science & Technology
Sunghun Kim, Youngjin Park, Seungbeom Yoo, Ocktaeck Lim, Bernike Febriana Samosir
Summary: Machine learning is applied to reduce the design period and improve the performance of the selective catalyst reduction system. This study identifies the factors affecting the design of the system and uses the Taguchi orthogonal array design to optimize the main design factors. Machine learning proves to be more efficient in determining the relationship between the factors and reduces processing time, leading to cost reduction and performance improvement.
Article
Chemistry, Multidisciplinary
Nguyen Van Tuan, Duong Quang Minh, Nguyen Xuan Khoa, Ocktaeck Lim
Summary: This study compared the prediction accuracy of Artificial Neural Network (ANN) and Support Vector Machine (SVM) machine learning models in forecasting ignition delays of diesel engines. The results showed that the SVM model outperformed the ANN model in predicting ignition delays.
