Ignition delay of dual fuel engine operating with methanol ignited by pilot diesel

Abstract

An investigation on the ignition delay of a dual fuel engine operating with methanol ignited by pilot diesel was conducted on a TY1100 direct-injection diesel engine equipped with an electronic controlled methanol lowpressure injection system. The experimental results show that the polytropic index of compression process of the dual fuel engine decreases linearly while the ignition delay increases with the increase in methanol mass fraction. Compared with the conventional diesel engine, the ignition delay increment of the dual fuel engine is about 1.5u at a methanol mass fraction of 62%, an engine speed of 1600 r/min, and full engine load. With the elevation of the intake charge temperature from 20uC to 40uC and then to 60uC, the ignition delay of the dual fuel engine decreases and is more obvious at high temperature. Moreover, with the increase in engine speed, the ignition delay of the dual fuel engine by time scale (ms) decreases clearly under all engine operating conditions. However, the ignition delay of the dual fuel engine increases remarkably by advancing the delivery timing of pilot diesel, especially at light engine loads.

Investigations on the combustion duration and ignition delay period of a dual fuel diesel engine with hydrogen and producer gas as secondary fuels

“…As a result, small time is required to form a stoichiometric mixture and hence ignition delay is small [11]. Further, for higher concentration of the gaseous fuel mixture at high load condition, the propagation of flame from various ignition centers of the pilot fuel is fast and consumes the largest part of the cylinder gaseous fuel-air mixture resulted in higher residual gas temperature [28]. Hence, ignition delay period reduces.…”

“…This may be due to the use of a large amount of cylinder gaseous fuel-air mixture by the flame initiated from the various ignition centers of the pilot fuel propagates at a faster rate which results in higher residual gas temperature [28].…”

Experimental investigations on combustion, performance and emissions characteristics of compression ignition engine powered by B100/ethanol blend

“…Ignition delay period consist of physical delay and chemical delay which occur simultaneously. In the physical delay takes place atomization, vaporization and mixing of air fuel, and in the chemical delay attributed pre-combustion reactions [25]. In Fig.…”

“…The highest THC emission was indicated for 35% of EF fraction in blend and it was higher of about 30% compared to pure B100 powering. In the literature it has also been observed that the presence of alcohol in the blends contributes the increase in THC emission [25]. The THC emission is higher since temperature is lower due to the higher heat of evaporation of ethanol fuel thus combustion poor.…”

Ignition Delay of Reactivity Controlled Compression Ignition (Rcci) for the Mixture of Diesel Fuel and Ethanol in a Rapid Compression Machine

“…Therefore, the start of pilot diesel injection and the start of combustion must be known to determine the ignition delay of dual fuel operated engine [14]. The start of pilot diesel injection can be defined as the time when the injector needle is lifted off its seat by the needle-lift indicator.…”