Hydrogen-enriched Engine Research Articles

The Current State of Hydrogen-Enriched Engine Development

In recent years, with the further strengthening of environmental protection, researchers have paid extensive attention to the hydrogen-enriched engine. hydrogen-enriched mix hydrogen with conventional fuels and are designed to reduce exhaust emissions, improve combustion efficiency and enhance power performance. Proper hydrogen incorporation can reduce carbon emissions and nitrogen oxide emissions, and improve engine power output and combustion efficiency. In this paper, four kinds of hydrogen-enriched engines are introduced comprehensively, and the effects of hydrogen-enriched ratio on combustion and emission performance of engines are analyzed, as well as the effects of different technologies on hydrogen-enriched engines. The research results show that hydrogen-enriched engines have significant advantages in reducing emissions, improving combustion efficiency and enhancing power performance, and become one of the important technologies for the future automotive industry to transition to clean energy.

Effect of CO2 dilution on combustion and emissions characteristics of the hydrogen-enriched gasoline engine

CO2 (Carbon dioxide) dilution is a feasible way for controlling NOx (Nitrogen oxides) emissions and loads of the internal combustion engines. This paper investigated the effect of CO2 dilution on the combustion and emissions characteristics of a hydrogen-enriched gasoline engine. The experiment was conducted on a 1.6 L spark-ignition engine with electronically controlled hydrogen and gasoline injection systems. At two hydrogen volume fractions of 0 and 3%, the CO2 volume fraction in the intake was gradually increased from 0 to 4%. The fuel-air mixtures were kept at the stoichiometric. The experimental results demonstrated that brake mean effective pressure of the gasoline engine was quickly reduced after adopting CO2 dilution. Comparatively, Bmep (Brake mean effective pressure) of the 3% hydrogen-enriched engine was gently decreased with the increase of CO2 dilution level. Thermal efficiency of the 3% hydrogen-enriched gasoline engine was raised under properly increased CO2 dilution levels. However, thermal efficiency of the pure gasoline engine was generally dropped after the CO2 dilution. The addition of hydrogen could shorten flame development and propagation durations under CO2 diluent conditions for the gasoline engine. Increasing CO2 fraction in the intake caused the dropped NOx and raised HC (Hydrocarbon) emissions. Increasing hydrogen fraction in the intake could effectively reduce HC emissions under CO2 diluent conditions.

Emission characteristics of an hydrogen–CH4 fuelled spark ignition engine

Abstract Hydrogen has many excellent combustion properties for improving combustion and emissions performance of spark ignition (SI) engines. This article presents a comparative energy and exergy analyses of a hydrogen–methane blends fuelled direct injection diesel engine. The engine was modified to realize hydrogen port injection by installing hydrogen injectors in the intake manifolds. Engine was used to obtain the experimental data at full load conditions for constant 3100-rpm speed. It is shown that exhaust exergy is inversely proportional to the hydrogen addition as well as bio diesel. After hydrogen addition brake thermal efficiency was rised and reached almost a constant value in a wide range. Regarding emission levels, CO 2 and HC emissions were reduced with hydrogen addition but CO emission tended to increase when excess air ratio was approaching stoichiometric conditions. However, when the engine was gradually leaned out, CO emission from the hydrogen-enriched engine was reduced. NO x emissions increased with the increase of hydrogen addition due to the raised cylinder temperature. The data are also very useful for operational changes needed to optimize the hydrogen fuelled SI engine design. Thus it has been shown that hydrogen is a good choice as an alternative engine fuel.

Performance and combustion analysis of hydrogen-fuelled C.I. engine with EGR

Crisis of fossil fuel and environmental degradation shift around the world to cleaner and more convenient forms of energy and resulting efficiency gains help moderate the increase in commercial and residential demand. Particularly in developing countries, these gains are helping improve the quality of life, while mitigating health problems.Experimental results showed lower exhaust emissions and improved performance using dual fuel mode with hydrogen as substitute fuel. It was also found that hydrogen enriched engine gives maximum efficiency at around 70% of full load whereas when operated with diesel this values come close to 80% of full load. At 70% of full load, the brake thermal efficiency was increased by 10.71% with the supply of 120 g/h of hydrogen at optimum injection timing in comparison to neat diesel due to better combustion characteristics of hydrogen. However, at high flow rates of hydrogen the availability of oxygen in combustion got reduced so the thermal efficiency decreased. BSEC in case of hydrogen enrichment was 11.6% less compared to that of neat diesel operation at 70% load. The reason for reduction in BSEC may be the homogeneous mixing of hydrogen in the combustion chamber resulting in improved combustion. The overall performance of hydrogen is comparable to that of Diesel. It can therefore be concluded that hydrogen is a good alternate fuel for future.

Engine performance of optimized hydrogen-fueled direct injection engine

The world is presently confronted with the twin crisis of fossil fuel depletion and environmental degradation. Indiscriminate extraction and lavish consumption of fossil fuels have led to reduction in underground based carbon resources. The search for an alternative fuel, which promises a harmonious correlation with sustainable development, energy conservation, management, efficiency, and environmental preservation, has become highly pronounced in the present context. For the developing countries of the world, fuels of bio-origin can provide a feasible solution to the crisis.In the present investigation, hydrogen-enriched air was used as intake charge in a CI (compression ignition) engine. Experiments were conducted in a single-cylinder, four-stroke, air-cooled, stationary direct-injection diesel engine Kirlosker TAF1 with 1500 rpm and 4.4 kW capacity coupled to an electrical generator. The injection timings (18.5, 20, 21.5, 24.5, 27.5° CA) and flow rates of hydrogen were varied (80, 120, 150 g/hr) to find out the optimum condition for hydrogen enrichment to meet the best performance. Experiment results showed that hydrogen enriched engine gave maximum brake thermal efficiency and minimum brake specific energy consumption at 16.4% H2 or 120 g/h flow rate with 20° CA injection timing.

Numerical investigation on the combustion process in a spark-ignited engine fueled with hydrogen–gasoline blends

This paper numerically investigated the combustion process in a spark-ignited (SI) engine fueled with hydrogen–gasoline blends through the computational fluid dynamics (CFD) calculation. Satisfying agreement between the calculated and measured in-cylinder pressure traces was observed for all test cases. The calculation results demonstrated that, the hydrogen addition availed the increased flame propagation speed and the enhanced degree of flame wrinkling. Compared with the original engine, the peak flame propagation speed was raised by 37.18% and 60.47% at the hydrogen volume fractions of 3% and 6%, respectively. The peak average flame surface densities of the 3% and 6% hydrogen-enriched engines were 28.88% and 35.99% higher than that of the original engine, respectively.

Effect of hydrogen addition on combustion and emissions performance of a spark ignition gasoline engine at lean conditions

Hydrogen has many excellent combustion properties that can be used for improving combustion and emissions performance of gasoline-fueled spark ignition (SI) engines. In this paper, an experimental study was carried out on a four-cylinder 1.6 L engine to explore the effect of hydrogen addition on enhancing the engine lean operating performance. The engine was modified to realize hydrogen port injection by installing four hydrogen injectors in the intake manifolds. The injection timings and durations of hydrogen and gasoline were governed by a self-developed electronic control unit (DECU) according to the commands from a calibration computer. The engine was run at 1400 rpm, a manifold absolute pressure (MAP) of 61.5 kPa and various excess air ratios. Two hydrogen volume fractions in the total intake of 3% and 6% were applied to check the effect of hydrogen addition fraction on engine combustion. The test results showed that brake thermal efficiency was improved and kept roughly constant in a wide range of excess air ratio after hydrogen addition, the maximum brake thermal efficiency was increased from 26.37% of the original engine to 31.56% of the engine with a 6% hydrogen blending level. However, brake mean effective pressure (Bmep) was decreased by hydrogen addition at stoichiometric conditions, but when the engine was further leaned out Bmep increased with the increase of hydrogen addition fraction. The flame development and propagation durations, cyclic variation, HC and CO 2 emissions were reduced with hydrogen addition. When excess air ratio was approaching stoichiometric conditions, CO emission tended to increase with the addition of hydrogen. However, when the engine was gradually leaned out, CO emission from the hydrogen-enriched engine was lower than the original one. NO x emissions increased with the increase of hydrogen addition due to the raised cylinder temperature.

04/02511 Performance simulation of a four-stroke enginewith variable stroke-length and compression ratio: Yamin, J. A. A. and Dado, M. H. Applied Energy, 2004, 77, (4), 447–463

The world is presently confronted with the twin crisis of fossil fuel depletion and environmental degradation. Indiscriminate extraction and lavish consumption of fossil fuels have led to reduction in underground based carbon resources. The search for an alternative fuel, which promises a harmonious correlation with sustainable development, energy conservation, management, efficiency, and environmental preservation, has become highly pronounced in the present context. For the developing countries of the world, fuels of bio-origin can provide a feasible solution to the crisis.In the present investigation, hydrogen-enriched air was used as intake charge in a CI (compression ignition) engine. Experiments were conducted in a single-cylinder, four-stroke, air-cooled, stationary direct-injection diesel engine Kirlosker TAF1 with 1500 rpm and 4.4 kW capacity coupled to an electrical generator. The injection timings (18.5, 20, 21.5, 24.5, 27.5° CA) and flow rates of hydrogen were varied (80, 120, 150 g/hr) to find out the optimum condition for hydrogen enrichment to meet the best performance. Experiment results showed that hydrogen enriched engine gave maximum brake thermal efficiency and minimum brake specific energy consumption at 16.4% H2 or 120 g/h flow rate with 20° CA injection timing.