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Krishna M.V.S.M.,Chaitanya Bharathi Institute of Technology | Janardhan N.,Chaitanya Bharathi Institute of Technology | Murthy P.V.K.,Vivekananda Institute of Science and Information Technology | Ushasri P.,Osmania University | Sarada N.,JNTUH College of Engineering
Archive of Mechanical Engineering | Year: 2012

Investigations were carried out to evaluate the performance of a low heat rejection (LHR) diesel engine consisting of different versions, such as ceramic coated cylinder head engine-LHR-1-Air gap insulated piston and air gap insulated liner-LHR-2- and Ceramic coated cylinder head, air gap insulated piston and air gap insulated liner -LHR-3 with degrees of insulation with normal temperature condition of linseed oil with varied injection pressure. Performance parameters were determined at various magnitudes of brake mean effective pressure. Pollution levels of smoke and oxides of nitrogen (NOx) were recorded at the peak load operation of the engine. Combustion characteristics of the engine were measured with TDC (top dead centre) encoder, pressure transducer, console and special pressure-crank angle software package. Conventional engine (CE) showed deteriorated performance, while LHR engine showed improved performance at recommended injection timing of 27°bTDC and recommend injection pressure of 190 bar with vegetable oil operation, when compared with CE with pure diesel operation. Peak brake thermal efficiency increased by 14%, smoke levels decreased by 10% and NOx levels increased by 30% with LHR engine at an injection pressure of 270 bar when compared with pure diesel operation on CE at manufacturer's recommended injection timing. Source


Janardhan N.,Chaitanya Bharathi Institute of Technology | Murali Krishna M.V.S.,Chaitanya Bharathi Institute of Technology | Ushasri P.,Osmania University | Murthy P.V.K.,Vivekananda Institute of Science and Information Technology
International Journal of Engineering Research in Africa | Year: 2014

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 efficiency] and exhaust emissions [smoke and oxides of nitrogen] 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 rise] 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 manufacturer's recommended injection timing. ©(2014) Trans Tech Publications, Switzerland. Source


Murali Krishna M.V.S.,ChaitanyaBharathi Institute of Technology | DurgaPrasadaRao N.,Hindustan Aeronautics Ltd | Murthy P.V.K.,Vivekananda Institute of Science and Information Technology
International Journal of Renewable Energy Research | Year: 2013

Investigations were carried out to evaluate the performance of a medium grade low heat rejection (LHR) diesel engine with air gap insulated piston and air gap insulated liner with 3-mm air gap at different operating conditions [normal temperature and pre-heated temperature] of crude rice brawn oil (CRBO) with varied injection pressure and injection timing. Performance parameters of brake thermal efficiency, exhaust gas temperature, volumetric efficiency, coolant load and sound intensity were determined at various values of brake mean effective pressure (BMEP). Exhaust emissions of smoke and oxides of nitrogen (NOx) were recorded at various values of BMEP. Combustion characteristics at peak load operation of the engine were measured with TDC (top dead centre) encoder, pressure transducer, console and special pressure-crank angle software package. Conventional engine (CE) showed deteriorated performance, while LHR engine showed improved performance with CRBO operation at recommended injection timing and pressure and the performance of both version of the engine improved with advanced injection timing and at higher injection pressure when compared with CE with pure diesel operation. The optimum injection timing was 32obTDC for CE while it was 30°bTDC with LHR engine with CRBO operation. Compatible performance in terms of peak brake thermal efficiency, exhaust gas temperature, coolant load, smoke levels were observed with LHR engine with CRBO operation at recommended injection timing of 27°bTDC(Before top dead centre) in comparison with pure diesel operation. Source


Murali Krishna M.V.S.,Chaitanya Bharathi Institute of Technology | Kishor K.,Chaitanya Bharathi Institute of Technology | Gupta A.V.S.S.K.S.,University of Hyderabad | Murthy P.V.K.,Vivekananda Institute of Science and Information Technology | Narasimha Kumar S.,Chaitanya Bharathi Institute of Technology
Journal of Renewable and Sustainable Energy | Year: 2012

This paper reports performance evaluation of two-stroke, single cylinder spark ignition (SI) engine with methanol blended gasoline (80 gasoline, 20 methanol by volume) having copper coated engine (CCE) [copper (thickness, 300 m) coated on piston crown, and inner side of cylinder head] provided with catalytic converter with sponge iron as catalyst and compared with conventional SI engine with gasoline operation. Brake thermal efficiency increased with methanol blended gasoline with both versions of the engine. CCE showed improved performance when compared to conventional engine (CE) with both test fuels. Catalytic converter with air injection significantly reduced pollutants with both test fuels on both configurations of the engine. © 2012 American Institute of Physics. Source


Murali Krishna M.V.S.,Chaitanya Bharathi Institute of Technology | Kishor K.,Chaitanya Bharathi Institute of Technology | Murthy P.V.K.,Vivekananda Institute of Science and Information Technology | Gupta A.V.S.S.K.S.,University of Hyderabad | Narasimha Kumar S.,Chaitanya Bharathi Institute of Technology
Renewable and Sustainable Energy Reviews | Year: 2012

Aim: Investigations were carried out to evaluate the performance of a two-stroke, single cylinder, spark ignition (SI) engine, with alcohol blended gasoline (80% gasoline, 20% methanol by vol; 80% gasoline and 20% ethanol by volume) having copper coated engine [CCE, copper-(thickness, 300 μm) coated on piston crown, inner side of cylinder head] provided with catalytic converter with sponge iron as catalyst and compared with conventional SI engine (CE) with pure gasoline operation. Study design: Performance parameters of brake thermal efficiency, exhaust gas temperature and volumetric efficiency were determined at various values of brake mean effective pressure (BMEP). Methodology: A microprocessor-based analyzer was used for the measurement of carbon monoxide (CO) and un-burnt hydro carbons (UBHC) in the exhaust of the engine at various values of BMEP. Aldehydes were measured by dinitrophenyl hydrazine (DNPH) method at peak load operation of the engine. Brief results: CCE with alcohol blended gasoline considerably reduced pollutants in comparison with CE with pure gasoline operation. Catalytic converter with air injection significantly reduced pollutants with test fuels on both configurations of the engine. Gasohol improved the performance of the both versions of the engine in comparison with methanol blended gasoline. On the other hand, methanol blended gasoline effectively reduced the emissions when compared with gasohol in both versions of the engine. © 2012 Elsevier Ltd. Source

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