Indian Journal of Science and Technology

Abstract

Background/Objectives: With the huge increase of fuel price, shortage of cured oil supply and air pollutions due to engine exhaust emission has made the authors to focus on the utilization of alternative fuels in SI engine, improving engine fuel economy and reducing the exhaust emission. The main objectives of this work is to utilize the alternative fuel, increase the performance, and to reduce the engine exhaust emissions like HC, CO, CO2 and NOx produced by the hydrogen fueled SI engine. Methods/Statistical Analysis: The SI engine was designed and modified to supply hydrogen manifold injection by using gaseous hydrogen injector installed in the intake manifold. The ignition timing maintained at optimum spark timing for best torque of the engine. The equivalence ratio was varied from 0.82 to 1.27 and 0.57 to 1.03 for gasoline and hydrogen operations respectively. The comparison of the fuel consumption, brake thermal efficiency and engine emissions running on gasoline and hydrogen fuel was done separately at a constant speed of 3000 rpm and at variable load conditions. Findings: For hydrogen operation, a lean equivalence ratio of around 0.6 was attained, whereas it was 0.82 with gasoline operation. The Brake-Specific Fuel Consumption (BSFC) lowers than gasoline as compared with hydrogen fuel at the higher thermal efficiency point. HC, CO, and CO2 emissions were negligible with hydrogen fuel. NOx is the only major regulatory emission present in the pure hydrogen fuel operation. NOx emission is very low at lower equivalence ratios. However, it was significantly higher than gasoline fuel at an equivalence ratio of 0.99 due to increased cylinder temperature. HC, CO, and CO2 emissions are negligible. Application/Improvements: This paper presents the experimental study conducted on a single cylinder, low power, SI engine fueled with hydrogen to evaluate its performance and emissions characteristics. The test results showed that the improved brake thermal efficiency was achieved at a lean equivalence ratio with hydrogen fuel. For hydrogen fuel operation, there is an increase of 3.59% brake thermal efficiency than the gasoline fuel at 1.44 kW power. However, there is an 18% reduction in the peak output power of the engine when operated with the hydrogen fuel. HC, CO, and CO2 emissions were very low for hydrogen operations when compared with gasoline.
Keywords: Emission Characteristics, Hydrogen Injector, Hydrogen Fuel, Manifold Injection, SI Engine, Thermal Efficiency