ANALYSIS OF THE THERMAL EFFICIENCY OF A DIESEL ENGINE OPERATING IN DIESEL AND ETHANOL DUAL-FUEL MODE

Author(s):  
Lucindo Soares Pereira ◽  
Paulo Roberto Wander ◽  
Josimar Souza Rosa
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):  
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.


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%.


2019 ◽  
Vol 8 (2) ◽  
pp. 1902-1905

The present energy scenario hydrogen fuel plays a dominant role in the power generation. Due to its unique characteristics of an extensive range of flammability, high flame speed, and diffusivity. In this present investigation, the diesel engine is converted into dual-fuel mode devoid of major conversions of the engine. The tests are performed on a dual-fuel mode and investigated the efficiency, emissions, and combustion features of the diesel engine. In the present context, hydrogen and biogas are injected from the inlet manifold as subsidiary fuel and diesel are injected as pilot fuel. The gaseous fuel injected in two different flow rates they are, 3 litres per minute (lpm), and 4lpm. The results from the experimentation revealed that the diesel with 4 lpm of hydrogen shows the 31.11 % enhancement of brake thermal efficiency but it shows 4.14% higher NOX emissions when compared with the pure diesel. But it shows. At the same time diesel with 4 lpm of Biogas exhibits 15.90% enhancement of brake thermal efficiency and 8.96% decrease in the NOX emissions in contrast to that of the single-mode of fuel with diesel.


Author(s):  
C. V. Sudhir ◽  
Vijay Desai ◽  
Y. Suresh Kumar ◽  
P. Mohanan

Reducing the emissions and fuel consumption for IC engines are no longer the future goals; instead they are the demands of today. People are concerned about rising fuel costs and effects of emissions on the environment. The major contributor for the increased levels of pollutants is the Diesel engines. Diesel engine finds application in almost in all fields, including transportation sector such as buses, trucks, railway engines, etc. and in industries as power generating units. In the present work an attempt is made for effective utilization of diesel engine aiming for reduction in fuel consumption and smoke density. This is achieved by some minor modifications in diesel engine, so as to run the existing diesel engine as a LPG-Diesel dual-fuel engine with LPG (Liquefied Petroleum Gas) induction at air intake. The important aspect of LPG-Diesel dual-fuel engine is that it shows significant reduction in smoke density and improved brake thermal efficiency with reduced energy consumption. An existing 4-S, single cylinder, naturally aspirated, water-cooled, direct injection, CI engine test rig was used for the experimental purpose. With proper instrumentation the tests were conducted under various LPG flow rates, loads, and injection timings. The influence of the diesel replacement by LPG on smoke density, brake specific energy consumption and brake thermal efficiency were studied. The optimal diesel replacement pertaining to the maximum allowable LPG gas flow limits could be assessed with these experiments. The influence of the injection timing variation on the engine performance and smoke density were analyzed form the experimental results. It was also observed that beyond half load operation of the dual-fuel engine, the brake thermal efficiency increases with diesel replacement, and at full load up to 4% improvement was observed compared to full diesel operation. At full load reduction in smoke density up to 25–36% was observed compared to full diesel operation. At advance injection timing of 30°btdc the performance was better with lower emissions compared to normal and retarded injection timings.


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.


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):  
N. Kapilan ◽  
Chandramohan Somayaji ◽  
P. Mohanan ◽  
R. P. Reddy

In the present work, an attempt has been made for the effective utilization of Compressed Natural Gas (CNG) in diesel engine. A four stroke, single cylinder diesel engine was modified to work on dual fuel mode. The effect of CNG flow rate and Exhaust Gas Recirclulation (EGR) on the performance and emissions of the dual fuel engine was studied. The variables considered for the tests were different CNG flow rates (0.2, 0.3, 0.4, 0.5, 0.6 and 0.7 kg/hr), EGR (0 %, 4.28 %, 6.63 % and 8.12 %) and loads (25 %, 50 %, 75 % and 100 % of full load). From the test results, it was observed that the EGR rate of 4.28 % results in better brake thermal efficiency and lower CO and NOx emissions than other ERG rates at 25 %, 50% and 75% of full loads. At full load, EGR rate of 8.12 % results in higher brake thermal efficiency and lower NOx emissions.


2021 ◽  
pp. 146808742110516
Author(s):  
Enrico Mattarelli ◽  
Carlo Alberto Rinaldini ◽  
Stefano Caprioli ◽  
Francesco Scrignoli

Dual Fuel (DF) combustion can help to reduce the environmental impact of internal combustion engines, since it may provide excellent Brake Thermal Efficiency (BTE) combined with ultra-low emissions. This technique is particularly attractive when using biofuels, or fuels with a low Carbon content, such as Natural Gas (NG). Unfortunately, as engine load decreases and the homogeneous NG-air mixture tends to become very lean, the high chemical stability of NG can be a serious obstacle to the completion of combustion. As a result, BTE drops and UHC and CO emissions become very high. A possible way to address this problem could be the addition of hydrogen (H2) to the NG-air mixture. In this paper, a numerical study has been carried out on an automotive Diesel engine, modified by the authors in order to operate in both conventional Diesel combustion and DF NG-diesel mode. A previous experimental characterization of the engine is the basis for the CFD-3D modeling and calibration of the DF combustion process, using a commercial software. The effects on combustion stability and emissions of different NG-H2 mixtures (six blends with 5%, 10%, 15%, 20%, 25%, and 30% by volume of hydrogen) are numerically investigated at a low load (BMEP = 2 bar, engine speed 3000 rpm). The results of the CFD-3D simulations demonstrate that NG-H2 blends are able to decrease strongly CO, UHC, and CO2 emissions at low loads. Advantages are also found in terms of thermal efficiency and NOx emissions.


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