Potential of a Medium Grade Low Heat Rejection Diesel Engine With Crude Tobacco Seed Oil

Author(s):  
M. V. S. Murali Krishna ◽  
P. Pavan Kumar ◽  
P. V. K. Murthy ◽  
D. Baswaraju

Investigations were carried out to evaluate the performance of a medium grade low heat rejection (LHR) diesel engine consisting of air gap insulated piston with 3-mm air gap, with superni (an alloy of nickel) crown and air gap insulated liner with superni insert with different operating conditions of crude tobacco seed oil with varied injection timing and injection pressure. Performance parameters of brake thermal efficiency (BTE), exhaust gas temperature (EGT), volumetric efficiency (VE), coolant load (CL) and sound intensity were determined at various values of brake mean effective pressure (BMEP) of the engine. Exhaust emissions of smoke and oxides of nitrogen (NOx) were noted at different values of BMEP of the engine. Combustion characteristics of peak pressure (PP), time of occurrence of peak pressure (TOPP), maximum rate of pressure rise (MRPR) and time of occurrence of maximum rate of pressure (TOMRPR) were measured with TDC (top dead centre) encoder, pressure transducer, console and special pressure-crank angle software-package at the peak load operation of the engine. Conventional engine (CE) showed deteriorated performance, while LHR engine showed improved performance with crude tobacco seed oil (CTSO) operation when compared with pure diesel operation at recommended injection timing and pressure. The optimum injection timing was found to be 32°bTDC (before top dead centre) with CE while it was 30°bTDC with LHR engine with vegetable oil operation. The performance of both version of the engine improved with advanced injection timing and higher injection pressure with test fuels. Peak brake thermal efficiency increased by 4%, volumetric efficiency decreased by 8%, smoke levels decreased by 4% and NOx levels increased by 37% with vegetable oil operation on LHR engine at its optimum injection timing, when compared with pure diesel operation on CE at manufacturer’s recommended injection timing of 27°bTDC.

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.


Author(s):  
M. V. S. Murali Krishna ◽  
C. M. Vara Prasad ◽  
Tandur Rajashekar ◽  
Supriya Tiwari ◽  
T. Sujani

Jatropha oil, a non-edible vegetable oil shows a greater potential for replacing conventional diesel fuel quite effectively, as its properties are compatible to that of diesel fuel. But low volatility and high viscosity of jatropha oil call for hot combustion chamber, which is provided by a low heat rejection diesel engine with threaded air gap piston and liner with superni-90 inserts. The performance of the engine with jatropha oil is obtained with different versions of the engine such as conventional engine and insulated engine at normal and preheat condition of the oil, with varying injection pressure and timing and compared to the engine with pure diesel operation at recommended injection pressure and timing. Increase of thermal efficiency of 18% and reduction of NOx levels by 5% are observed at optimized injection timing and at higher injection pressure with insulated engine at preheat condition of jatropha oil in comparison with pure diesel operation on conventional engine.


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.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Ch. Kesava Reddy ◽  
M. V. S. Murali Krishna ◽  
P. V. K. Murthy ◽  
T. Ratna Reddy

Investigations are carried out to evaluate the performance of a low heat rejection (LHR) diesel engine with ceramic coated cylinder head [ceramic coating of thickness 500 microns is done on inside portion of cylinder head] with different operating conditions [normal temperature and pre-heated temperature] of crude Pongamia oil (CPO) with varied injection pressure and injection timing. Performance parameters and pollution levels are determined at various magnitudes of brake mean effective pressure. Combustion characteristics at peak load operation of the engine are measured with special pressure-crank angle software package. Conventional engine (CE) showed deteriorated performance, while LHR engine showed improved performance with CPO operation at recommended injection timing and pressure and the performance of both version of the engine is improved with advanced injection timing and at higher injection pressure when compared with CE with pure diesel operation. The optimum injection timing is 31°bTDC for conventional engine while it is 29°bTDC with LHR engine with vegetable oil operation. Peak brake thermal efficiency increased by 5%, smoke levels decreased by 2% and NOx levels increased by 40% with CPO operation on LHR engine at its optimum injection timing, when compared with pure diesel operation on CE at manufacturer’s recommended injection timing.


Author(s):  
Srinath Pai ◽  
Abdul Sharief ◽  
Shiva Kumar

A single cylinder diesel engine upgraded to operate Common Rail Direct Injection (CRDI) system and employed in this investigation. Tests were conducted on this engine using High-Speed diesel (HSD) and Simarouba biodiesel (SOME) blends to determine the influence of Injection Pressure (IP) and Injection Timing (IT) on the performance and emissions. Four unique IP of 400 bar to 1000 bar, in steps of 200 bar and four differing ITs of 10°, 13°, 15° and 18° before Top Dead Center (bTDC) combinations were attempted for the 25% to full load. Compression Ratio (CR) of 16.5 and Engine speed of 1500 RPM was kept constant during all trails. Critical performance parameter like Brake Thermal Efficiency (BTE) and Brake Specific Fuel Consumption (BSFC) were analyzed, primary emission parameters of the diesel engine The NOx and Smoke opacity were recorded. Finally, the outcomes of each combination were discussed.


2015 ◽  
Vol 813-814 ◽  
pp. 830-835
Author(s):  
Akkaraju H. Kiran Theja ◽  
Rayapati Subbarao

The drawbacks associated with bio-fuels can be minimized by making modifications to combustion chamber. Modification of combustion chamber is achieved by providing an air gap in between the crown and the body of the piston with the top crown made of low thermal conductivity material. Experimentation is carried on a diesel engine with brass as piston crown material and karanja as test fuel, which is found to be a better alternative fuel based on the tests carried out prior to modification. Investigations are carried out on the performance of the engine with modified combustion chamber consisting of air gap insulated piston with 2 mm air gap with brass crown when fuelled with karanja oil. Comparative studies are made between the two configurations of engine with and without modification at an injection timing of 29obTDC. Performance, heat balance and emission plots are made with respect to brake power. Fuel consumption increased with modification. The mechanical and volumetric efficiencies are similar in both the cases. Indicated and brake thermal efficiencies got reduced with modification. But, it is good to see that HC and CO emissions are showing positive trend. Thus, the present investigation hints the possibility of improvements while making piston modification and providing air gap insulation.


2018 ◽  
Vol 15 (5) ◽  
pp. 562-566
Author(s):  
Vijaya K. ◽  
Shailesh Palaparty ◽  
Raghavan Srinivasa ◽  
Ravi Kumar Puli

Purpose Investigations are carried out with the aim of improving performance of a diesel engine with the design modification on piston crown to stimulate the uniform combustion by inducing turbulence in the incoming charge. Design/methodology/approach A stirrer is introduced at the top of the piston so as to inculcate more turbulence to the incoming charge by improving the rate of fuel vaporization. Whirling motion is created in the combustible mixture by providing rotating blades on the cavity/bowl of the reciprocating piston head. By putting a simple link mechanism, the oscillatory motion of connecting rod will rotate the blade by an angle of 60°. Findings The investigations are carried out with and without swirl piston at 17.5 compression ratio and 200 bar injection pressure by varying injection timings. Originality/value Finally, the result shows that by using the modified piston, nearly 3 per cent of efficiency increased and 31 per cent of NOx emissions are reduced compared to that of a normal piston with 80 per cent load at standard injection timing.


2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Pushpendra Kumar Sharma ◽  
Dilip Sharma ◽  
Shyam Lal Soni ◽  
Amit Jhalani

Excessive use of diesel engines and continuous increase in environmental pollution has drawn the attention of researchers in the area of the compression ignition engine. In this research article, an innovative investigation of the nonroad modified diesel engine is reported with the effective use of the hybrid Entropy-VIKOR approach. Hence, it becomes necessary to prioritize and optimize the performance defining criteria, which provides higher BTE along with lower emission simultaneously. The engine load, injection timing (Inj Tim), injection pressure (Inj Pre), and compression ratio (Com R) were selected as engine operating parameters for experimentation at the constant speed of 1500 rpm engine. The effect on engine performance parameters (BTE and BSEC) and emission (carbon monoxide (CO), total oxide of carbon (TOC), oxides of nitrogen (NOx), hydrocarbon (HC), and smoke) was studied experimentally. The optimum results were observed at load 10.32 kg, Inj Tim 20 deg btdc, Inj Pre 210 bar, and Com R 21:1 at which highest BTE of 22.24% and lowest BSEC of 16,188.5 kJ/kWh were obtained. Hybrid entropy-VIKOR approach was applied to establish the optimum ranking of the nonroad modified diesel engine. The experimental results and numerical simulation show that optimizing the engine operating parameters using the entropy-VIKOR multicriteria decision-making (MCDM) technique is applicable.


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