scholarly journals A comparative experimental study on engine operating on premixed charge compression ignition and compression ignition mode

2017 ◽  
Vol 21 (1 Part B) ◽  
pp. 441-449
Author(s):  
Girish Bhiogade ◽  
Jiwak Suryawanshi

New combustion concepts have been recently developed with the purpose to tackle the problem of high emissions level of traditional direct injection Diesel engines. A good example is the premixed charge compression ignition combustion. A strategy in which early injection is used causing a burning process in which the fuel burns in the premixed condition. In compression ignition engines, soot (particulate matter) and NOx emissions are an extremely unsolved issue. Premixed charge compression ignition is one of the most promising solutions that combine the advantages of both spark ignition and compression ignition combustion modes. It gives thermal efficiency close to the compression ignition engines and resolves the associated issues of high NOx and particulate matter, simultaneously. Premixing of air and fuel preparation is the challenging part to achieve premixed charge compression ignition combustion. In the present experimental study a diesel vaporizer is used to achieve premixed charge compression ignition combustion. A vaporized diesel fuel was mixed with the air to form premixed charge and inducted into the cylinder during the intake stroke. Low diesel volatility remains the main obstacle in preparing premixed air-fuel mixture. Exhaust gas re-circulation can be used to control the rate of heat release. The objective of this study is to reduce exhaust emission levels with maintaining thermal efficiency close to compression ignition engine.

Author(s):  
Bibhuti B. Sahoo ◽  
Niranjan Sahoo ◽  
Ujjwal K. Saha

Synthesis gas (Syngas), a mixture of hydrogen and carbon monoxide, can be manufactured from natural gas, coal, petroleum, biomass, and even from organic wastes. It can substitute fossil diesel as an alternative gaseous fuel in compression ignition engines under dual fuel operation route. Experiments were conducted in a single cylinder, constant speed and direct injection diesel engine fuelled with syngas-diesel in dual fuel mode. The engine is designed to develop a power output of 5.2 kW at its rated speed of 1500 rpm under variable loads with inducted syngas fuel having H2 to CO ratio of 1:1 by volume. Diesel fuel as a pilot was injected into the engine in the conventional manner. The diesel engine was run at varying loads of 20, 40, 60, 80 and 100%. The performance of dual fuel engine is assessed by parameters such as thermal efficiency, exhaust gas temperature, diesel replacement rate, gas flow rate, peak cylinder pressure, exhaust O2 and emissions like NOx, CO and HC. Dual fuel operation showed a decrease in brake thermal efficiency from 16.1% to a maximum of 20.92% at 80% load. The maximum diesel substitution by syngas was found 58.77% at minimum exhaust O2 availability condition of 80% engine load. The NOx level was reduced from 144 ppm to 103 ppm for syngas-diesel mode at the best efficiency point. Due to poor combustion efficiency of dual fuel operation, there were increases in CO and HC emissions throughout the range of engine test loads. The decrease in peak pressure causes the exhaust gas temperature to rise at all loads of dual fuel operation. The present investigation provides some useful indications of using syngas fuel in a diesel engine under dual fuel operation.


Author(s):  
Amir Ridhuan ◽  
Shahrul Azmir Osman ◽  
Mas Fawzi ◽  
Ahmad Jais Alimin ◽  
Saliza Azlina Osman

This introductory study comes up with an innovative idea of using Hydroxyl gas as a fuel performance enhancer to reduce the natural sources and the overuse of fossil fuel resulting in increased pollution levels. Many researchers have used HHO gas to analyze gasoline and diesel in internal combustion engines. The main challenges of using HHO gas in engines have been identified as system complexity, safety, cost, and electrolysis efficiency. This article focuses on different performance reports and the emission characteristics of a compression ignition engine. As opposed to general diesel, this study found that using HHO gas improved brake power and torque. In all cases, an increase in braking thermal efficiency can be observed. This was due to the presence of hydrogen in HHO gas with higher calorific value than fossil fuels. At the same time, the fuel consumption unit of the engine was reduced, and the combined impact of hydrogen and oxygen helped to achieve complete combustion and improved the combustion capacity of the fuel when HHO gas was injected. The addition of HHO gas also improved the Brake Power (BP), Brake Torque (BT), Brake Specific Fuel Consumption (BSFC), and thermal efficiency while simultaneously reducing CO and HC formation. The rise in CO2 emissions represented the completion of combustion. Therefore, the usage of HHO gas in the Compression Ignition (CI) engine improved the engine performance and exhaust emissions.


2020 ◽  
pp. 146808742095132
Author(s):  
José V Pastor ◽  
Antonio García ◽  
Carlos Micó ◽  
Felipe Lewiski

Considering the need of pollutant emissions reduction and the high cost of the after-treatment systems, in-cylinder solutions for pollutant reduction are becoming more and more relevant. Among different proposals, new piston geometries are considered an attractive solution for reducing both soot and nitrogen oxides emissions in compression ignition engines. For this reason, this paper evaluates the soot formation and combustion characteristics of a novel piston geometry proposal, called stepped lip-wave, for light-duty engines. It is compared with other two well-known bowl geometries: re-entrant and stepped lip. The study was performed in an optical single-cylinder direct injection compression ignition engine. Two optical techniques (2 color pyrometry and OH* chemiluminescence) were applied for analyzing soot formation in each piston geometry. Test were performed at different engine loads, fuel injection characteristics and exhaust gas recirculation configuration. The re-entrant piston presents higher soot formation and a slower late oxidation process in comparison with the other two geometries. Stepped lip and stepped lip-wave present similar soot formation levels. However, stepped lip-wave showed a more efficient and faster soot oxidation process during the final combustion stages. Results confirm the potential of the stepped lip-wave concept to reduce soot emissions and achieve a cleaner energy production system.


2018 ◽  
Vol 20 (1) ◽  
pp. 69-79 ◽  
Author(s):  
Jeongwoo Lee ◽  
Sanghyun Chu ◽  
Jaegu Kang ◽  
Kyoungdoug Min ◽  
Hyunsung Jung ◽  
...  

In this research, there are two major sections for analysis: the characteristics of gasoline and diesel dual-fuel combustion and their application to operating load extension with high thermal efficiency and low emissions. All the experiments were completed using a single-cylinder compression ignition engine with 395 cc displacement. In the first section, the dual-fuel combustion modes were classified into three cases by their heat release rate shapes. Staying at 1500 r/min with a total value of 580 J of low heat for each cycle condition, the diesel injection timing was varied from before top dead center with a 6–46 °crank angle with 70% of gasoline fraction based on the low heating value. Among the modes were two suitable dual-fuel combustion modes for a premixed compression ignition. The first suitable mode shows multiple peaks in the heat release rate (mode 2) and the second suitable mode shows a single peak with a “bell-shaped” heat release rate (mode 3). These two dual-fuel combustion types showed a high gross indicated thermal efficiency of up to 46%. Based on the results in the first section, the practical application of dual-fuel premixed compression ignition combustion was investigated considering a high thermal efficiency and a high-load condition. At a 1500 r/min/gross indicated mean effective pressure of 6.5 bar, 48% of the gross indicated thermal efficiency was obtained by using dual-fuel premixed compression ignition combustion mode 3. This mode was typical of a “reactivity controlled compression ignition,” while the nitrogen oxides and the particulate matter emissions satisfied the EURO-6 regulation (0.21 g/kW h and 2.8 mg/m3, respectively). In addition, a high thermal efficiency (45%) with low maximum pressure rise rate, NOx (nitrogen oxides), and particulate matter emissions was obtained at 2000 r/min/gross indicated mean effective pressure 14 bar condition by the adjustment of dual-fuel premixed compression ignition combustion mode 2. As a result, this research contributes to the understanding and practical application of dual-fuel combustion for a light-duty compression ignition engine.


2015 ◽  
Vol 163 (4) ◽  
pp. 47-56
Author(s):  
Łukasz KAPUSTA

In this study dual fuel direct injection was studied in terms of utilizing in compression ignition engines gaseous fuels with high octane number which are stored in liquid form, specifically liquid propane. Due to the fact that propane is not as much knock-resistant as natural gas, instead of conventional dual fuel system a system based on simultaneous direct injection of two fuel was selected as the most promissing one. Dual fuel operation was compared with pure diesel operation. The performed simulations showed huge potential of dual fuel system for burning light hydrocarbons in heavy duty compression ignition engines. However, further secondary fuel injection system optimization is required in order to improve atomization and lower the emissions.


Author(s):  
Gopal Kumar Deshmukh ◽  
Ammenur Rehman ◽  
Rajesh Gupta

Jatropha-curcas biodiesel has recently been considered as one of the potential renewable energy sources in Asia. This biodiesel is produced through the transesterification process of the non-edible oil obtained from Jatropha-curcas. The properties of this biodiesel are quite similar to those of diesel fuel. However, high viscosity of pure Jatropha-curcas biodiesel adversely affects engine performance. Hence, the percentage of Jatrophacurcas biodiesel that will not cause any adverse effect on the engine must be determined. In this context, this paper experimentally investigates the performance and exhaust emission characteristics of a direct injection compression ignition engine fuelled with 25%, 50% and 100% volume basis Jatropha-curcas biodiesel with diesel. Results showed that the Jatropha-curcas biodiesel and its blends demonstrated lower values for brake thermal efficiency and exhaust emission levels than diesel, but not for nitrogen oxide levels and brake specific fuel consumption. It was observed that the blend containing 25% Jatropha-curcas biodiesel (BD25) was the best alternative for diesel fuel based on engine emissions and overall performance. Therefore, BD25 could be considered a potential alternative fuel for compression ignition engines.


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