Effect of Load Level on the Performance of a Dual Fuel Compression Ignition Engine Operating on Syngas Fuels With Varying H2/CO Content

Author(s):  
B. B. Sahoo ◽  
U. K. Saha ◽  
N. Sahoo

Syngas, an environmentally friendly alternative gaseous fuel for internal combustion engine operation, mainly consists of carbon monoxide (CO) and hydrogen (H2). It can substitute fossil diesel oil in a compression ignition diesel engine through dual fuel operation route. In the present investigation, experiments were conducted in a constant speed single cylinder direct injection diesel engine fuelled with syngas-diesel in a dual fuel operation mode. The main contribution of this study is to introduce the new synthetic gaseous fuel (syngas) including the possible use of CO gas, an alternative diesel engine fuel. In this work, four different H2 and CO compositions of syngas were chosen for dual fuel study under different engine loading levels. Keeping the same power output at the corresponding tested loads, the engine performance of dual fuel operations were compared to that of diesel mode for the entire load range. The maximum diesel replacement in the engine was found to be 72.3% for 100% H2 fuel. This amount replacement rate was reduced for the low energetic lower H2 content fuels. The brake thermal efficiency was always found highest (about 21%) in the case of diesel mode operation. However, the 100% H2 syngas showed a comparative performance level with diesel mode at the expense of higher NOx emissions. At 80% engine load, the brake thermal efficiency was found to be 15.7% for 100% CO syngas. This value increased to 16.1%, 18.3% and 19.8% when the 100% CO syngas composition was replaced by H2 contents of 50%, 75% and 100%, respectively. At part loads (i.e., at 20% and 40%), dual fuel mode resulted a poor performance including higher emission levels. In contrast, at higher loads, syngas fuels showed a good competitive performance to diesel mode. At all the tested loads, the NOx emission was observed highest for 100% H2 syngas as compared to other fuel conditions, and a maximum of 240 ppm was found at 100% load. However, when the CO fractions of 25%, 50% and 100%, were substituted to hydrogen fuel, the emission levels got reduced to 175 ppm, 127 ppm, and 114 ppm, respectively. Further, higher CO and HC emission levels were recorded for 25%, 50%, and 100% CO fraction syngas fuels due to their CO content. Ignition delay was found to increase for the dual fuel operation as compared to diesel mode, and also it seemed to be still longer for higher H2 content syngas fuels. The peak pressure and maximum rate of pressure rise were found to decrease for all the cases of dual fuel operation, except for 100% H2 syngas (beyond 60% load). The reduction in peak pressure resulted a rise in the exhaust gas temperature at all loads under dual fuel operation. The present investigation provides some useful experimental data which can be applied to the possible existing engine parameters modifications to produce a competitive syngas dual fuel performance at all the loading operations.

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.


2020 ◽  
Vol 12 (3) ◽  
pp. 129-136
Author(s):  
Avinash MUTLURI ◽  
Radha Krishna GOPIDESI ◽  
Srinivas Viswanath VALETI

In the present research a diesel engine has been converted to dual fuel mode, injecting hydrogen and biogas as secondary fuel and the tests were conducted in dual fuel mode to evaluate the performance, emissions and combustion parameters of the engine. Diesel as a pilot fuel, hydrogen and biogas as a secondary fuel were injected from the inlet manifold. The hydrogen and the biogas which is a gaseous fuel were injected at 5 liters per minute (lpm) and the tests were conducted separately. From these tests, it was noted that there is an enhancement of 27.28% in brake thermal efficiency (BTE) and increment of 10.70% in NOX emissions for diesel with 5 lpm hydrogen compared with diesel fuel under single fuel mode. Also, it was noted that the reduction in BTE was around 36.50% and NOX emissions about 15.68 % for diesel with 5 lpm biogas when compared with diesel fuel under single fuel mode.


2011 ◽  
Vol 110-116 ◽  
pp. 1368-1373 ◽  
Author(s):  
Amar P. Pandhare ◽  
S. G. Wagholikar ◽  
R. B. Jadhav Sachin Musale ◽  
A. S. Padalkar

The heterogeneous catalyst are environment friendly and render the process simplified. A wide variety of solid bases have been examined for this process. The present work reports the use of hydrotalcite catalyst for the synthesis of Biodiesel from jatropha oil. An experimental investigation has been carried out to analyze the performance and emission characteristics of a compression ignition engine fuelled with Jatropha oil and its blends (10%, 20%, 40%, 50%, and 60 % ) with mineral diesel. The effect of temperature on the viscosity of Jatropha oil has also been investigated. A series of engine tests, have been conducted using each of the above fuel blends for comparative performance evaluation. The performance parameters evaluated include thermal efficiency, brake specific fuel consumption (BSFC), brake specific energy consumption (BSEC), and exhaust gas temperature whereas exhaust emissions include mass emissions of CO, HC, NO. These parameters were evaluated in a single cylinder compression ignition diesel engine. The results of the experiment in each case were compared with baseline data of mineral diesel. Significant improvements have been observed in the performance parameters of the engine as well as exhaust emissions. The gaseous emissions of oxide of nitrogen from all blends are lower than mineral diesel at all engine loads. Jatropha oil blends with diesel (up to 50% v/v) can replace diesel for operating the CI engines giving lower emissions and improved engine performance. More over results indicated that B20 have closer performance to diesel and B100 have lower brake thermal efficiency mainly due to its high viscosity compared to diesel.


Author(s):  
T. Lakshmanan ◽  
A. Khadeer Ahmed ◽  
G. Nagarajan

Gaseous fuels are good alternative fuels to improve the energy crisis of today’s situation due to its clean burning characteristics. However, the incidence of backfire and knock remains a significant barrier in commercialization. With the invention of latest technology, the above barriers are eliminated. One such technique is timed injection of water into the intake port. In the present investigation, acetylene was aspirated in the intake manifold of a single cylinder diesel engine, with a gas flow rate of 390 g/h, along with water injected in the intake port, to overcome the backfire and knock problems in gaseous dual fuel engine. The brake thermal efficiency and emissions such as NOx, smoke, CO, HC, CO2 and exhaust gas temperature were studied. Dual fuel operation of acetylene induction with injection of water results in lowered NOx emissions with complete elimination of backfire and knock at the expense of brake thermal efficiency.


Author(s):  
M. Senthil Kumar ◽  
A. Ramesh ◽  
B. Nagalingam

Different methods to improve the performance of a jatropha oil based compression ignition engine were tried and compared. A single cylinder water-cooled, direct injection diesel engine was used. Base data were generated with diesel and neat jatropha oil. Subsequently, jatropha oil was converted into its methyl ester by transesterification. Jatropha oil was also blended with methanol and orange oil in different proportions and tested. Further, the engine was modified to work in the dual fuel mode with methanol, orange oil, and hydrogen being used as the inducted fuels and the jatropha oil being used as the pilot fuel. Finally, experiments were conducted using additives containing oxygen, like dimethyl carbonate and diethyl ether. Neat jatropha oil resulted in slightly reduced thermal efficiency and higher emissions. Brake thermal efficiency was 27.3% with neat jatropha oil and 30.3% with diesel. Performance and emissions were considerably improved with the methyl ester of jatropha oil. Dual fuel operation with methanol, orange oil, and hydrogen induction and jatropha oil injection also showed higher brake thermal efficiency. Smoke was significantly reduced from 4.4 BSU with neat jatropha oil to 2.6 BSU with methanol induction. Methanol and orange oil induction reduced the NO emission and increased HC and CO emissions. With hydrogen induction, hydrocarbon and carbon monoxide emissions were significantly reduced. The heat release curve showed higher premixed rate of combustion with all the inducted fuels mainly at high power outputs. Addition of oxygenates like diethyl ether and dimethyl carbonate in different proportions to jatropha oil also improved the performance of the engine. It is concluded that dual fuel operation with jatropha oil as the main injected fuel and methanol, orange oil, and hydrogen as inducted fuels can be a good method to use jatropha oil efficiently in an engine that normally operates at high power outputs. Methyl ester of jatropha oil can lead to good performance at part loads with acceptable levels of performance at high loads also. Orange oil and methanol can be also blended with jatropha oil to improve viscosity of jatropha oil. These produce acceptable levels of performance at all outputs. Blending small quantity of diethyl ether and dimethyl carbonate with jatropha oil will enhance the performance. Diethyl ether seems to be the better of the two.


Author(s):  
Brandon J. Blizman ◽  
Darby B. Makel ◽  
J. Hunter Mack ◽  
Robert W. Dibble

A demonstration system has been developed intending to meet the California Energy Commission’s primary goal of improving California’s electric energy cost/value by providing a low-cost, high-efficiency distributed power generation system that operates on landfill gas as fuel. The project team led by Makel Engineering, Inc. includes UC Berkeley, CSU Chico and the Butte County Public Works Department. The team has developed a reliable, multi-cylinder Homogeneous Charge Compression Ignition (HCCI) engine by converting a Caterpillar 3116, 6.6 liter diesel engine to operate in HCCI mode. This engine utilizes a simple and robust thermal control system. Typically, HCCI engines are based on standard diesel engine designs with reduced complexity and cost based on the well known principles of engine dynamics. Coupled to an induction generator, this HCCI genset allows for simplified power grid connection. Testing with this HCCI genset allowed for the development of a control system to maintain optimal the inlet temperature and equivalence ratio. A brake thermal efficiency of 35.0% was achieved while producing less than 10.0 ppm of NOx and 30 kW of electrical power. Less than 5.0 ppm of NOx was recorded with a slightly lower brake thermal efficiency. Tests were conducted with both natural gas and simulated landfill gas as a fuel source. This demonstration system has shown that landfill gas fueled Homogeneous Charge Compression Ignition engine technology is a viable technology for distributed power generation.


Author(s):  
N. Janardhan ◽  
M.V.S. Murali Krishna ◽  
P. Ushasri ◽  
P.V.K. Murthy

Investigations were carried out to evaluate the performance of a low heat rejection (LHR) diesel engine consisting of air gap insulated piston with 3-mm air gap, with superni (an alloy of nickel) crown, air gap insulated liner with superni insert and ceramic coated cylinder head with different operating conditions of crude jatropha oil (CJO) with varied injection timing and injector opening pressure . Performance parameters [brake thermal efficiency, exhaust gas temperature, coolant load and volumetric efficienc and exhaust emissions [smoke and oxides of nitroge were determined at various values of brake mean effective pressure (BMEP). Combustion characteristics [ peak pressure, time of occurrence of peak pressure and maximum rate of pressure ris of the engine were at peak load operation of the engine. Conventional engine (CE) showed deteriorated performance, while LHR engine showed improved performance with vegetable operation at recommended injection timing and pressure. The performance of both versions of the engine improved with advanced injection timing and higher injector opening pressure when compared with CE with pure diesel operation. Relatively, peak brake thermal efficiency increased by 14%, smoke levels decreased by 27% and NOx levels increased by 49% with vegetable oil operation on LHR engine at its optimum injection timing, when compared with pure diesel operation on CE at manufacturers recommended injection timing.


2013 ◽  
Vol 388 ◽  
pp. 217-222
Author(s):  
Mohamed Mustafa Ali ◽  
Sabir Mohamed Salih

Compression Ignition Diesel Engine use Diesel as conventional fuel. This has proven to be the most economical source of prime mover in medium and heavy duty loads for both stationary and mobile applications. Performance enhancements have been implemented to optimize fuel consumption and increase thermal efficiency as well as lowering exhaust emissions on these engines. Recently dual fueling of Diesel engines has been found one of the means to achieve these goals. Different types of fuels are tried to displace some of the diesel fuel consumption. This study is made to identify the most favorable conditions for dual fuel mode of operation using Diesel as main fuel and Gasoline as a combustion improver. A single cylinder naturally aspirated air cooled 0.4 liter direct injection diesel engine is used. Diesel is injected by the normal fuel injection system, while Gasoline is carbureted with air using a simple single jet carburetor mounted at the air intake. The engine has been operated at constant speed of 3000 rpm and the load was varied. Different Gasoline to air mixture strengths investigated, and diesel injection timing is also varied. The optimum setting of the engine has been defined which increased the thermal efficiency, reduced the NOx % and HC%.


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