Impact of ammonia addition on knock resistance and combustion performance in a gasoline engine with high compression ratio

Liu, Shang; Lin, Zhelong; Zhang, Hao; Lei, Nuo; Qi, Yunliang; Wang, Zhi

doi:10.1016/j.energy.2022.125458

Cited by 48 publications

(6 citation statements)

References 36 publications

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“…The net ROP’s absolute value is negative, rising with the initial temperature. It is observed that all reactions are enhanced with increasing temperature, and the increasing pressure also leads to an enhancement of these reactions according to ref . Given that under engine-relevant pressures, thermal-type NO reactions (Zeldovich mechanism) occur at much lower rates than fuel-type NO reactions .…”

Section: Resultsmentioning

confidence: 85%

Optical Study on the Effects of Wall and Intake Temperatures on Ammonia Combustion and Emissions

Zhang,

Chen,

et al. 2024

Energy Fuels

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Ammonia (NH3) as an alternative carbon-free fuel suffers from poor combustion and emission performance, limiting its large-scale commercial utilization in the automobile industry. It has been shown that ammonia combustion is sensitive to operating boundary conditions of actual engines. In this work, the effects of thermodynamic boundary conditions (i.e., wall and intake temperature) on ammonia combustion and emissions were investigated using an optical spark-ignition engine with a high compression ratio. Wall and intake temperatures were regulated by a coolant and an intake heater, respectively. The results show that raising the wall temperature can significantly improve combustion stability, combustion efficiency, and thermal efficiency, while intake temperatures can enhance ammonia combustion only when the wall temperature reaches beyond some thresholds. Combustion visualization shows that the intake and wall temperature affect different stages of the combustion process. Specifically, the intake temperature might predominantly influence the early stages of combustion, whereas the wall temperature might have a more significant impact on the entire combustion process. Elevating the intake temperature increases the flame propagation speed, while there are no obvious changes in terms of the wall temperature. Flame analysis shows that a high wall temperature corresponds to a lower flame stretch sensitivity, indicating reduced cyclic variations in flame propagation and alleviating the possibility of flame quenching. While a high intake temperature features a stronger flame response to turbulence at the early stage of flame development. Besides, NH3 and N2O emissions are significantly reduced due to the improvement of flame propagation instability and incomplete combustion based on the crevice mechanism, but there is an increase in NO and NO2 emissions. The chemical kinetic analysis indicates that increasing NO x emissions mainly comes from the temperature and pressure sensitivities of fuel-type NO x .

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Section: Resultsmentioning

confidence: 85%

Optical Study on the Effects of Wall and Intake Temperatures on Ammonia Combustion and Emissions

Zhang,

Chen,

et al. 2024

Energy Fuels

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“…In contrast, NH 3 has a significantly low stoichiometric air fuel proportion than traditional hydrocarbon fuel. 74 Therefore more NH 3 can be burned using the same amount of air, and more NH 3 could compensate because of its low energy/mass content. 75…”

Section: Resultsmentioning

confidence: 99%

Optimization of ideal engine parameters to adopt ammonia and algae biodiesel for reactivity controlled compression ignition engine using response surface methodology

Elumalai,

Ravi

2023

Proceedings of the Institution of Mechanical Engineers, Part C:

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Renewable and green fuels like carbon-free ammonia and carbon neutral algal-biodiesel appear to be more promising alternatives. Reactivity controlled compression ignition offers a viable alternative to classical combustion. In current delving, compression ratio, injection timing and premixing ratio are established by investigating the combustion, performance, and emission parameters of reactivity-controlled compression ignition operation fueled with ammonia and algae biodiesel as low reactive and high reactive fuel. Primarily, different compression ratio (16, 17, and 18) for different ammonia energy premixing fractions (20%, 30%, 40%, and 50%) at 80% load with standard injection time (24° before top dead center) was evaluated to identify the ideal compression ratio. Next stage, different Injection timing (24°, 26°, and 28° before top dead center) was examined with that ideal compression ratio at 80% load utilizing combustion attributes. Finally, with the ideal compression ratio and injection timing (18° and 26°), the performance and emission for various ammonia energy premixing fractions (20%, 30%, 40%, and 50%) on the entire load ranges (20%, 40%, 60%, 80%, and 100%) were investigated and the optimal fuel fraction was arrived by multi objective optimization technique in response surface methodology by considering response weights. The multi objective optimization result enhances the 43% ammonia premixing combustion. The experimental validation of 43% ammonia premixing combustion achieved the best brake thermal efficiency of 34.02% whereas fuel consumption is 12.72 MJ/kWh. The maximum emission rate of hydrocarbon, carbon monoxide, carbon dioxide, oxides of nitrogen and smoke opacity is 47 ppm, 0.084% volume, 2.04% volume 593 ppm and 15.9%. In comparison to the Conventional biodiesel combustion, an increase in efficiency of 3.34% and a decrease in energy consumption of 3.72% are achieved for the 43% ammonia energy premixing combustion. Similarly, emissions were reduced by 45.35%, 44%, 46.25%, 23.44%, and 28.38% respectively than conventional biodiesel combustion.

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“…NH 3 's anti-knock properties enable NH 3 /gasoline SI engines to operate at higher pressures, resulting in improved work efficiency [33]. While a high CR can significantly enhance the combustion characteristics of NH 3 fuel, a CR of 12:1 or higher is not recommended due to the intersection of the minimum advance of the optimal torque detonation limit and rough limit crossover [36]. The schematic diagram of the ammonia and gasoline mixed-combustion test process as shown in Figure 4.…”

Section: Combustion and Emission Of Nh 3 /Gasoline Si Enginesmentioning

confidence: 99%

Application of NH3 Fuel in Power Equipment and Its Impact on NOx Emissions

Hu,

Liu,

et al. 2024

Energies

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Due to high greenhouse gas emissions, countries worldwide are stepping up their emission reduction efforts, and the global demand for new, carbon-free fuels is growing. Ammonia (NH3) fuels are popular due to their high production volume, high energy efficiency, ease of storage and transportation, and increased application in power equipment. However, their physical characteristics (e.g., unstable combustion, slow flame speed, and difficult ignition) limit their use in power equipment. Based on the structural properties of the power equipment, NH3 fuel application and emissions characteristics were analyzed in detail. Combustion of NH3 fuels and reduction measures for NOx emissions (spark plug ignition, compression ignition, and gas turbines) were analyzed from various aspects of operating conditions (e.g., mixed fuel, fuel-to-exhaust ratio, and equivalence ratio), structure and strategy (e.g., number of spark plugs, compression ratio (CR), fuel injection, and ignition mode), and auxiliary combustion techniques (e.g., preheating, humidification, exhaust gas recirculation, and secondary air supply). The performance of various NH3 fuel cell (FC) types was analyzed, with a focus on the maximum power achievable for different electrolyte systems. Additionally, the application and NOx emissions of indirect NH3 FCs were evaluated under flame and catalytic combustion conditions. The system efficiency of providing heat sources by burning pure NH3, anode tail gas, and NH3 decomposition gas was also compared. Based on a comprehensive literature review, the key factors influencing the performance and emissions of NH3-powered equipment were identified. The challenges and limitations of NH3-powered equipment were summarized, and potential strategies for improving efficiency and reducing emissions were proposed. These findings provide valuable insights for the future development and application of NH3 FCs.

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Impact of ammonia addition on knock resistance and combustion performance in a gasoline engine with high compression ratio

Cited by 48 publications

References 36 publications

Optical Study on the Effects of Wall and Intake Temperatures on Ammonia Combustion and Emissions

Optical Study on the Effects of Wall and Intake Temperatures on Ammonia Combustion and Emissions

Optimization of ideal engine parameters to adopt ammonia and algae biodiesel for reactivity controlled compression ignition engine using response surface methodology

Application of NH3 Fuel in Power Equipment and Its Impact on NOx Emissions

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