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With the development of new energy, hydrogen fuel engines have become a research boom in the automotive field. But there are abnormal problems such as backfire and pre-ignition during the combustion of hydrogen engines. This paper is based on the Ant Colony Optimization-Back Propagation (ACO-BP) algorithm to study the influence of different speed and load conditions on the ignition advance angle, so as to optimize the control of the hydrogen engine. The experimental system is established on a hydrogen engine converted from a 492Q gasoline engine. The prediction of the optimal ignition advance angle was obtained through experiments, and the optimal ignition MAP diagram of the hydrogen engine is constructed. The optimal ignition advance angle under different working conditions can effectively avoid the occurrence of hydrogen engine pre-ignition. The accuracy reaches 0.0018209 when the training reaches 14 times, the fitness between the actual value and the predicted value of ACO-BP training is 0.99921, the verification accuracy reaches 0.99913, and the test accuracy reaches 0.99932. Compared with the three optimization methods, the convergence speed and error accuracy of ACO-BP are significantly better than the BP neural networks and Genetic Algorithm-Back Propagation (GA-BP). This method realized the model of the nonlinear mapping model from hydrogen engine speed and load to optimal ignition advance angle, which is of great significance for solving the problem of abnormal combustion in hydrogen engine. • Research carried out by the 492Q hydrogen engine, close to actual conditions. • The dataset is original, collected under different speed and load conditions. • ACO-BP can be applied in abnormal combustion of hydrogen fuel engines. • Less relevant dataset, we will publish the dataset for future research. [ABSTRACT FROM AUTHOR]

Abstract The effect of the addition of hydrogen (H 2) on the combustion process and nitric oxide (NO) formation in a H 2 -diesel dual fuel engine was numerically investigated. The model developed using AVL FIRE as a platform was validated against the cylinder pressure and heat release rate measured with the addition of up to 6% (vol.) H 2 into the intake mixture of a heavy-duty diesel engine with exhaust gas recirculation (EGR). The validated model was applied to further explore the effect of the addition of 6%–18% (vol.) H 2 on the combustion process and formation of NO in H 2 -diesel dual fuel engines. When the engine was at N = 1200 rpm and 70% load, the simulation results showed that the addition of H 2 prolonged ignition delay, enhanced premixed combustion, and promoted diffusion combustion of the diesel fuel. The maximum peak cylinder pressure was observed with addition of 12% (vol.) H 2. In comparison, the maximum peak heat release rate was observed with the addition of 16% (vol.) H 2. The addition of H 2 was a crucial factor dominating the increased NO emissions. Meanwhile, the addition of H 2 reduced soot emissions substantially, which may be due to the reduced diesel fuel burned each cycle. Furthermore, proper combination of adding H 2 with EGR can improve combustion performance and reduce NO emissions. Highlights • Numerical model used to explore effect of H 2 addition on diesel engine performance. • H 2 addition improves combustion, reduces soot, but increases NOx emissions. • Combined H 2 addition/EGR improves combustion performance, reduces NOx emissions. [ABSTRACT FROM AUTHOR]

Recycling and reusing of exhaust gas from solid oxide fuel cell (SOFC) could enhance the fuel utilization of methane. In the present work, the effects of two main components of exhaust gas, viz. hydrogen and carbon dioxide, on the performance of exhaust gas reforming methane fueled cell were investigated. The cell with Ni/8 mol% Y 2 O 3 doped zirconia (Ni/YSZ) as the anode was exposed to H 2 CO 2 CH 4 atmospheres at 800 °C. DC techniques and impedance spectroscopy was used for characterization. Two kinds of cells with different fuel utilization factors ( U f ) were used in experiments, which represented different relationship of power density/voltage with current density. The results indicated that electrooxidation of H* dominated the electrochemical reaction on the anode of the cell at low U f value, while electrooxidation of C* becomes important at high U f value. In the case of CO 2 H 2 mixtures, CO 2 improved the exchange current density, raised the value of U f , and depressed anodic activation polarization. As for H 2 CH 4 CO 2 system, H 2 , partly replacing CH 4 , reduced the heat loss in dry reforming, improved the exchange current density, raised U f value, and depressed the activation and concentration polarization resistances of Ni/YSZ anode. But it had limited effect on the power density of the cell with high U f value. [ABSTRACT FROM AUTHOR]

La-doped Sr 2-x La x Fe 1.5 Mo 0.5 O 6-δ perovskite oxides are synthesized and used as a symmetric electrode to evaluate the effect of La on the crystal structure, conductivity, and catalytic activity for O 2 reduction and H 2 oxidation reaction. The electronic doping effect dominates the oversize effect in Sr 2-x La x Fe 1.5 Mo 0.5 O 6-δ oxide, resulting in unit cell volume expansion and decreased conductivity in air. In addition, the introduction of La increases the chemical structural stability of Sr 2 Fe 1.5 Mo 0.5 O 6-δ in reducing condition due to the higher La–O bond compared with Sr–O bond, leading to high catalytic activity for the H 2 oxidation reaction. At 800 °C, the R p values of Sr 1.9 La 0.1 Fe 1.5 Mo 0.5 O 6-δ symmetric cell in air and wet H 2 are as low as 0.075 and 0.21 Ω cm2, respectively. Moreover, the peak power densities of 769, 561, 439, and 653 mW cm−2 at 850 °C are obtained when wet H 2 , CO, CH 4, and C 3 H 8 are used as fuels on Sr 1.9 La 0.1 Fe 1.5 Mo 0.5 O 6-δ /LSGM/Sr 1.9 La 0.1 Fe 1.5 Mo 0.5 O 6-δ cell. The symmetric cell also shows excellent stability (>100 h) in wet H 2 /air, implying Sr 1.9 La 0.1 Fe 1.5 Mo 0.5 O 6-δ oxide is a promising symmetric electrode material. [Display omitted] • The substitution of La improves the stability of Sr 2 Fe 1.5 Mo 0.5 O 6-δ in reducing atmosphere. • La enhances the catalytic activity for H 2 oxidization reaction (HOR). • High electrochemical performance is obtained for SLFM symmetric cell under carbon-based fuels. [ABSTRACT FROM AUTHOR]