Search Results

Many countries are developing strategies to curb the consumption of fossil fuels, and to increase the share of alternative fuels such as alcohols, natural gas, fuel cell and electricity in the energy pool in order to improve energy security and reduce atmospheric pollution. Alcohol fuels are promising one and it has been widely used in many countries as blending component for gasoline. Ethanol has a high-octane number but it has a lower calorific value than gasoline. The performance of engine may be affected with higher percentage of ethanol in gasoline due to demand for larger quantity of fuel that could not be supplied by vehicles which are tuned to run on gasoline only. In this study, a second electronic control unit (ECU) was installed in series with the existing commercial or primary ECU and an ethanol sensor was installed in the fuel line. This secondary ECU modulates the fuel injection pulse width of the primary ECU depending on ethanol concentration in the fuel.

In view of the depletion of energy and environmental pollution, dual fuel technology has caught the attention of researchers as a viable technology keeping in mind the increased availability of fuels like Compressed Natural Gas (CNG). It is an ecologically friendly technology due to lower particulate matter (PM) and smoke emissions and retains the efficiency of diesel combustion. Generally, dual fuel technology has been prevalent for large engines like marine, locomotive and stationary engines. However, its use for automotive engines has been limited in the past due to constraints of the limited supply of alternative fuels. CNG is a practical fuel under dual-fuel mode operation, with varying degree of success. The induction method prevents a premixed natural gas-air mixture, minimizes the volumetric efficiency and results in a loss of power at higher speeds.

Natural gas has been considered and implemented as alternative fuel to gasoline and diesel powered vehicles worldwide. Although natural gas belongs to petroleum fuel family, it has considerable recourses worldwide to ensure long energy security and comparatively lower carbon to hydrogen ratio that make it more environment friendly. This paper presents the effect of long duration endurance test on gas engine oil along with performance and emission characteristics of 5.8 L turbocharged heavy duty natural gas engine. The six cylinder engine was chosen due to its importance for urban bus transportation. The engine was subjected to long duration endurance test of 800 hrs with closed loop monitoring and controlled conditions as per 6 mode engine load cycle. During the complete endurance test of 800 hours, performance and emission characteristics of the engine were analyzed after completion of every 100 hours as per Full Throttle Performance Test and European Transient Cycle (ETC).

In the light of major research work carried out on the detrimental health impacts of ultrafine particles (<50 nm), Euro VI emission standards incorporate a limit on particle number, of which ultrafine particles is the dominant contributor. As Compressed Natural Gas (CNG) is a cheaper and cleaner fuel when compared to diesel, there has been a steady increase in the number of CNG vehicles on road especially in the heavy duty segment. Off late, there has been much focus on the nature of particle emissions emanating from CNG engines as these particles mainly fall under the ultrafine particle size range. The combustion of lubricant is considered to be the dominant source of particle emissions from CNG engines. Particle emission due to lubricant is affected by the oil transport mechanisms into the combustion chamber which in turn vary with engine operating conditions as well as with the physico chemical properties of the lubricant.

Advances in renewable energy sources and impact of green house gases on climate change have led intense research in the area of renewable energy for transport and power generation sectors. All over the world gaseous fuels have gained momentum as an ideal alternative fuel for meeting future energy needs. Hydrogen enriched compressed natural gas (HCNG) may be considered as an alternative automotive fuel which does not require any major modification in the existing CNG engine and infrastructure. Several studies of HCNG fuel were reported on small and light duty engines / vehicles, but limited reports are available on heavy duty engines. In this study, experimental investigations were carried out on a 6 cylinder heavy duty CNG engine which has been optimized for 18 percent HCNG. Initial performance of the engine on HCNG was compared vis-à-vis CNG and, thereafter, the engine was subjected to endurance test as per BIS 10000 norms for 100 hours (severe cycle) with HCNG.