Article
Thermodynamics
Hakan Aygun, Mehmet Kirmizi, Ulas Kilic, Onder Turan
Summary: The application of small turbojet engines is increasing due to their high power to weight ratio and reliability. This study analyzes the effects of different design variables on the performance metrics of small turbojet engines. By using multi-objective genetic algorithm, particle swarm optimization, and grey wolf optimization, the study considers several performance metrics of the engines. The findings show that increasing turbine inlet temperature improves net thrust but increases specific fuel consumption, while increasing compressor pressure ratio decreases net thrust but reduces specific fuel consumption. The optimization results suggest that different optimization methods can be utilized depending on the specific mission of the turbojet engine.
Article
Energy & Fuels
Mustafa Deniz Altinkurt, Menno Merts, Martin Tuner, Ali Turkcan
Summary: Accelerated by the harms and depletion risk of fossil fuels, transition to low-carbon or renewable fuels have become an urgent need for combustion engines to decarbonize transport sectors. Natural gas-diesel dual-fuel combustion is a promising method to achieve these goals by allowing the usage of natural gas in diesel engines. However, this concept has drawbacks of low combustion efficiency, high unburned hydrocarbon (HC) emissions and high cyclic variations at low engine loads. To find solutions to these drawbacks, split diesel injections with variable injection timings and mass split ratios were investigated experimentally and numerically. The results showed that split injection had the potential to reduce HC emissions and cyclic variations, improve combustion efficiency, and decrease NOx emissions. Furthermore, simulations demonstrated that early single injection dual-fuel cases contributed to a more homogeneous temperature distribution and better oxidization of methane near the cylinder wall and central region above the piston crown.
Article
Thermodynamics
Yazan S. M. Altarazi, Abd Rahim Abu Talib, Ezanee Gires, Jianglong Yu, John Lucas, Talal Yusaf
Summary: Researchers studied the performance and emissions rate of the KingTech K180 turbojet engine running on dual biodiesel and its blend with Jet-A fuel, finding that the B10-Jet blend performed the best in terms of specific fuel consumption and emissions rate.
Article
Energy & Fuels
Mads Carsten Jespersen, Thomas Osterby Holst Rasmussen, Anders Ivarsson
Summary: This study investigates the lean-burn characteristics of ammonia in a pre-mixed SI engine and the influence of spark energy and discharge characteristics on engine performance and emissions. The results show that by optimizing the spark ignition system, the need for an ignition improver can be mitigated. The emissions of unburned ammonia and NOx are kept at low levels, and the balance between NH3 and NOx emissions is achieved by advancing the ignition timing.
Article
Multidisciplinary Sciences
Sehmus Altun, Mujdat Firat, Mutlu Okcu
Summary: This study investigates the effect of hydrogen addition on combustion characteristics in a diesel engine operated in RCCI mode. The results show that adding hydrogen can improve thermal efficiency and reduce fuel consumption, but it also leads to higher NOx emissions.
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
(2023)
Article
Engineering, Aerospace
Ismail Hakki Hakki Akcay, Habib Gurbuz, Husameddin Akcay, Mustafa Aldemir
Summary: This study investigates the impact of euro diesel-hydrogen dual-fuel combustion on static thrust, thrust specific energy consumption (TSEC) and exhaust emissions in a small turbojet engine. Experimental studies show a decrease in TSEC between 1% and 4.8% with different hydrogen energy fractions. The use of hydrogen as an alternative fuel shows improvements in performance and exhaust emissions in gas turbine engines.
AIRCRAFT ENGINEERING AND AEROSPACE TECHNOLOGY
(2021)
Article
Energy & Fuels
Seyed Morteza Mousavi, Hesameddin Fatehi, Xue-Song Bai
Summary: This paper presents a numerical study on flow, reactions, and NOx emissions from a biomass boiler, utilizing detailed reaction mechanisms and CFD simulations. The study identifies different pathways for NOx formation and evaluates the performance of the Selective Non-Catalytic Reduction (SNCR) method, showing a reduction of up to 63% in NOx emissions.
Article
Energy & Fuels
Zhijie Zhu, Xingyu Liang, Lei Cui, Kun Wang, Xiaohui Wang, Shihao Zhu
Summary: Currently, most ships still rely on fossil fuels as the main source for marine engines. However, diesel as a fuel for marine engines is no longer sufficient to meet the economic requirements of shipping and emission restrictions imposed by regulations. This research examined the viability of employing hydrogen-carrying fuel ammonia (NH3) in marine engines to develop a low-carbon combustion technology, to address the carbon emission problem of marine diesel engines.
Article
Energy & Fuels
Habib Gurbuz, Husameddin Akcay, Mustafa Aldemir, Ismail Hakki Akcay, Uemit Topalci
Summary: This study investigates the effects of euro diesel-hydrogen dual-fuel combustion on the performance and environmental-economic indicators of a small turbojet engine suitable for UAV propulsion systems. The results show that with the increase of hydrogen energy fractions, there is a decrease in specific energy consumption, CO and CO2 emissions, but an increase in HC and NOx emissions.
Article
Energy & Fuels
Limin Geng, Leichao Bi, Qi Li, Hao Chen, Yuantao Xie
Summary: The study found that adding ethanol to biodiesel improves spray characteristics and combustion performance in diesel engines. At low loads, peak cylinder pressures (PCPs) of BE blends are higher than diesel, while peak heat release rates (PHRRs) are also higher. However, at medium-high loads, PHRRs decrease and emissions decrease with increasing ethanol blending ratio.
Article
Energy & Fuels
Soner Sen
Summary: The aim of this study is to investigate the effects of using CSP and Jet-A blended fuel on the performance of the GasTurb Details-6 engine. The results show that the blended fuel reduces the thrust and increases the fuel consumption and CO2 emission. However, it also has a positive effect on reducing the CO emission and accelerates the formation of NOx.
ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS
(2023)
Article
Mechanics
Guangyao Rong, Miao Cheng, Yunzhen Zhang, Zhaohua Sheng, Jianping Wang
Summary: Numerical simulations were conducted to investigate the flow field characteristics and performance of a carbon-hydrogen/oxygen-rich air rotating detonation engine (RDE). The results showed that reducing the hydrogen equivalence ratio and particle diameter contributed to the transition from gas-phase single-front detonation to gas-solid two-phase double-front detonation. The effects of the solid fuel particle diameter and hydrogen equivalence ratio on the flow field characteristics and performance were revealed. Reducing the particle diameter enhanced the speed of the detonation wave and improved the pressure gain and specific impulse. Decreasing the hydrogen equivalence ratio reduced the detonation wave speed, enhanced the stability of the flow field, increased the pressure gain and thrust. The optimal operational conditions for stable and high-performance RDE were discussed.
Article
Energy & Fuels
Jicang Si, Guochang Wang, Ziyun Shu, Xiangtao Liu, Mengwei Wu, Rong Zhu, Jianchun Mi
Summary: This study investigates the effects of different diluents and oxygen concentrations on MILD oxy-combustion, finding that CO2 and H2O dilutions are more beneficial for flameless combustion, while N2 is superior for stable combustion at low oxygen levels. N2 dilution leads to high NOx emissions, while CO2 and H2O dilutions result in lower emissions and more uniform heat transfer characteristics. Additionally, the criteria for flameless MILD combustion proposed by Cavaliere and de Joannon and Wiinning and Wiinning are found to apply under CO2 and H2O dilutions but not under N2 dilution for high oxygen concentrations.
Review
Chemistry, Applied
Anh Tuan Hoang
Summary: The addition of CeO2 nanoparticles into biodiesel has shown positive effects on improving fuel performance and emissions of diesel engines. However, further research is needed to investigate the impacts of CeO2 nanoparticles on particulate matter emissions, human health, and the environment.
FUEL PROCESSING TECHNOLOGY
(2021)
Article
Energy & Fuels
Raphael Hatz, Alexander Lukas, Andreas Zepf, Malte Jaensch
Summary: This paper describes a simulative approach to calibrate a highly turbocharged industrial diesel engine for higher low-speed torque. The engine aims to achieve close to 30 bar effective mean pressure through suitable calibration between compression ratio, piston-bowl shape and injection strategy. The simulations involve the use of 3D CFD software for in-cylinder calibration and a 1D full-engine model for prediction. The results show that with maximum increase in fuel mass and boost pressure, the effective mean pressure could be increased up to 28 bar, while specific consumption only slightly increased. Depending on the geometry, emissions such as NOx or CO and UHC could be reduced.
Article
Thermodynamics
Pengcheng Zhao, Jingang Wang, Liming Sun, Yun Li, Haiting Xia, Wei He
Summary: The production of green hydrogen through water electrolysis is crucial for renewable energy utilization and decarbonization. This research explores the optimal electrode configuration and system design of compactly-assembled industrial electrolyzer. The findings provide valuable insights for industrial application of water electrolysis equipment.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
V. Baiju, P. Abhishek, S. Harikrishnan
Summary: Thermally driven adsorption desalination systems (ADS) have gained attention as an eco-friendly solution for water scarcity. However, they face challenges related to low water productivity and scalability. To overcome these challenges, integrating ADS with other desalination technologies can create a small-scale hybrid system. This study proposes integrating ADS with a Thermo Electric Dehumidification (TED) unit to enhance its performance.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
C. X. He, Y. H. Liu, X. Y. Huang, S. B. Wan, Q. Chen, J. Sun, T. S. Zhao
Summary: A decentralized centroid multi-path RC network model is constructed to improve the temperature prediction accuracy compared to traditional RC models. By incorporating multiple heat flow paths and decentralizing thermal capacity, a more accurate prediction is achieved.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Chaoying Li, Meng Wang, Nana Li, Di Gu, Chao Yan, Dandan Yuan, Hong Jiang, Baohui Wang, Xirui Wang
Summary: There is an urgent need to shift away from heavy dependence on fossil fuels and embrace renewable energy sources, particularly in the energy-intensive oil refining process. This study presents an innovative concept called the Solar Oil Refinery, which applies solar energy in oil refining. A solar multi-energies-driven hybrid chemical oil refining system that utilizes solar pyrolysis and electrolysis has been developed, significantly improving solar utilization efficiency, cracking rate, and hydrogen yield.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Chao Ma, Guanghui Wang, Dingbiao Wang, Xu Peng, Yushen Yang, Xinxin Liu, Chongrui Yang, Jiaheng Chen
Summary: This study proposes a bio-inspired fish-tail wind rotor to improve the wind power efficiency of the traditional Savonius rotor. Through transient simulations and orthogonal experiments, the key factors affecting the performance are identified. A response surface model is constructed to optimize the power coefficient, resulting in an improvement of 9.4% and 6.6% compared to the Savonius rotor.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Sina Bahmanziari, Abbas-Ali Zamani
Summary: This paper proposes a new framework for improving electrical energy harvesting from piezoelectric smart tiles through a combination of magnetic plucking, mechanical impact, and mechanical vibration force mechanisms. Experimental results demonstrate a significant increase in energy yield and average energy harvesting time compared to other mechanisms.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Nanjiang Dong, Tao Zhang, Rui Wang
Summary: This study establishes a multiobjective mixed-variable configuration optimization model for a comprehensive combined cooling, heating, and power energy system, and proposes an efficient generating operator to optimize this model. The experimental results show that the proposed algorithm performs better than other state-of-the-art algorithms.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Ahmed E. Mansy, Eman A. El Desouky, Tarek H. Taha, M. A. Abu-Saied, Hamada El-Gendi, Ranya A. Amer, Zhen-Yu Tian
Summary: This study aims to convert office paper waste into bioethanol through a sustainable pathway. The results show that physiochemical and enzymatic hydrolysis of the waste can yield a high glucose concentration. The optimal conditions were determined using the Box-Behnken design, and a blended membrane was used for ethanol purification.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Sven Klute, Marcus Budt, Mathias van Beek, Christian Doetsch
Summary: Heat pumps are crucial for decarbonizing heat supply, and steam generating heat pumps have the potential to decarbonize the industrial sector. This paper presents the current state, technical and economic data, and modeling principles of steam generating heat pumps.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Le Zhang, To-Hung Tsui, Yen Wah Tong, Pruk Aggarangsi, Ronghou Liu
Summary: This study investigates the effectiveness of a current-carrying-coil-based magnetic field in promoting anaerobic digestion of chicken manure. The results show that the applied magnetic field increases methane yield, decreases carbon dioxide production, and reduces the concentration of ammonia nitrogen. Microbial community analysis reveals the enrichment of certain methanogenic genera and enhanced metabolic pathways. Pilot-scale experiments confirm the technical effectiveness of the magnetic field assistance in enhancing anaerobic digestion of chicken manure.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Bo Chen, Ruiqing Ma, Yang Zhou, Rui Ma, Wentao Jiang, Fan Yang
Summary: This paper presents an advanced energy management strategy for fuel cell hybrid electric heavy-duty vehicles, focusing on speed planning and energy allocation. By utilizing predictive co-optimization control, this strategy ensures safe inter-vehicle distance and minimizes energy demand. Simulation results demonstrate the effectiveness of the proposed method in reducing fuel cell degradation cost and overall operation cost.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Fabio Fatigati, Roberto Cipollone
Summary: Organic Rankine Cycle-based microcogeneration systems that use solar sources to generate electricity and hot water can help reduce CO2 emissions in residential energy-intensive sectors. The adoption of a recuperative heat exchanger in these systems improves efficiency, reduces thermal power requirements, and saves on electricity costs.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Lipeng He, Renwen Liu, Xuejin Liu, Xiaotian Zheng, Limin Zhang, Jieqiong Lin
Summary: This research proposes a piezoelectric-electromagnetic hybrid energy harvester (PEHEH) for low-frequency wave motion and self-sensing wave environment monitoring. The PEHEH shows promising power output and the ability to self-power and self-sense the wave environment.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Shangling Chu, Yang Liu, Zipeng Xu, Heng Zhang, Haiping Chen, Dan Gao
Summary: This paper studies a distributed energy system integrated with solar and natural gas, analyzes the impact of different parameters on its energy utilization and emissions reduction, and obtains the optimal solution through an optimization algorithm. The results show that compared to traditional separation production systems, this integrated system achieves higher energy utilization and greater reduction in carbon emissions.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Qingpu Li, Yaqi Ding, Guangming Chen, Yongmei Xuan, Neng Gao, Nian Li, Xinyue Hao
Summary: This paper proposes and studies a piston-type thermally-driven pump with a structure similar to a linear compressor, aiming to eliminate the high-quality energy consumption of existing pumps and replace mechanical pumps. The coupling mechanism of working fluid flow and element dimension is analyzed based on force analysis, and experimental data analysis is used to determine the pump operation stroke. Theoretical simulation is conducted to analyze the correlation mechanism of the piston assembly. The research shows that the thermally-driven pump can greatly reduce power consumption and has potential for industrial applications.
ENERGY CONVERSION AND MANAGEMENT
(2024)