Study of Quasi‐Dimensional Combustion Model of Hydrogen‐ Enriched Compressed Natural Gas (HCNG) Engines

The reserves of the petroleum‐based fuels are directly correlated with the increasing demand of human mankind for energy production. With the growing world populations, industries, vehicles, and equipment, energy demand leads to the search for the substitute of petroleum fuels, which can cater for the need of people today. Considering the current global economic crisis, the interest in alternative fuels is extremely high. It is known that there is a limited amount of fossil‐based fuels as a sustainable energy source. The majority of the energy used today is obtained from the fossil fuels. Due to the continuing increase over the cost of fossil fuels, demands for clean energy have also been increasing. With this increasing demand for energy very soon the petroleum fuels will be depleted so researchers are focusing on to find the ways and means to generate cheap and abundant renewable and clean energy sources. Moving ahead with these plans, hydrogen‐enriched compressed natural gas (HCNG) engines have emerged as a future energy carrier for an internal combustion engine. Several countries are striving hard to bring down the pollution level by promoting hydrogen‐enriched compressed natural gas‐fueled vehicles in general by powering heavy vehicles like transportation buses as well as passenger cars. In general, under certain conditions, the indicated thermal efficiency of the HCNG engine is much better than CNG engines without compromising the high level of pollutant emissions. Even so, the hydrogen addition to CNG increases the NOx emission, due to high heat generated inside combustion chamber. This can be minimized by application of lean‐burn combustion or with three‐way catalyst

In-cylinder combustion analysis of a SI engine fuelled with hydrogen enriched compressed natural gas (HCNG): engine performance, efficiency and emissions

The main objective of this study was to investigate the effect of hydrogen addition on spark ignition (SI) engine’s performance, thermal efficiency, and emission using variable composition hydrogen/CNG mixtures. The hydrogen was used in amounts of 0%, 20%, 40% by volume fraction at each engine speed and load. Experimental analysis was performed at engine speed of 1200 rpm, load of 120 Nm corresponding BMEP = 0.24 MPa, spark timing 26 CAD BTDC, and at engine speed of 2000 rpm, load of 350 Nm corresponding BMEP = 0.71 MPa, spark timing 22 CAD BTDC. The investigation results show that increasing amounts of hydrogen volume fraction contribute to shorten ignition delay time and decrease of the combustion duration, that also affect main combustion phase. The combustion duration analysis of mass fraction burned (MFB) was presented in the article. Decrease of CO2 in the exhaust gases was observed with increase of hydrogen amounts to the engine. However, nitrogen oxides (NOX) were found to increase with hydrogen addition if spark timing was not optimized according to hydrogen’s higher burning speed