Investigating the effect of the air inlet temperature on the combustion characteristics of a spark ignition engine fueled by biogas

Abstract

This work has conducted a numerical study using AVL‐Boost engine simulation utilizing biogas (CH4 and CO2)–air mixtures in a SI engine model. The effect of varying the air manifold temperature from 25 to 50°C on the combustion characteristics as well as engine performance under full load condition in a SI engine fueled by gasoline and biogas mixtures has been investigated. The performed tests involved using variable concentrations of CO2 from 10% to 40% by volume. The current model has been validated with experimental results and it was found that the error in predicting the P‐θ behavior of the engine is about 4.89%. The results showed that, as the air inlet temperature increases, the volumetric efficiency decreases and the brake specific fuel consumption (BSFC) increases for gasoline and all biogas compositions. However, the peak pressure, brake output power, maximum pressure rise rate, and maximum heat release rate were decreased slightly with the increase in air inlet temperature. The effect was only observed for gasoline and the 10%‐CO2 biogas, whereas the effect on the maximum heat release rate was detected on gasoline and biogas compositions up to 20%‐CO2 only. On the other hand, the existence and growth of CO2 content in the biogas reduced significantly the peak pressure, brake output power, maximum pressure rise rate, volumetric efficiency, and both net and maximum heat release rates, though its effect in reducing the volumetric efficiency stopped at 20%‐CO2 biogas. Furthermore, BSFC rises noticeably with the increase in CO2 ratio in biogas. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.

An experimental and numerical investigation of the effects of the diaphragm pressure ratio and its position on a heated shock tube performance

“…A variety of recent studies were conducted involved using shock tubes along with high‐density fuel/air mixtures to obtain combustion features of conventional and alternative fuels at conditions relevant to those used in internal combustion engines and gas turbine machines 5‐8 . Ignition delay time (IDT), particularly in internal combustion engines, is a vital combustion characteristic that directly affects engine efficiency and exhaust emissions 9‐13 . This property in ICE can be defined as the time required to detect heat release once the air–fuel mixture reaches the self‐ignition (autoignition) temperature and pressure or the time interval between the start of ignition (raising injector needle) and the beginning of combustion 14 .…”

“…[5][6][7][8] Ignition delay time (IDT), particularly in internal combustion engines, is a vital combustion characteristic that directly affects engine efficiency and exhaust emissions. [9][10][11][12][13] This property in ICE can be defined as the time required to detect heat release once the air-fuel mixture reaches the self-ignition (autoignition) temperature and pressure or the time interval between the start of ignition (raising injector needle) and the beginning of combustion. 14 The total delay period is due to a combination of physical and chemical delays.…”