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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Energy Management and Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Exhaust emissions,DME Fuel,Engine Performance,piston bowl design,air-fuel mixing
- چکیده:
- چکیده انگلیسی: By development of industries, excessive consumption of the fossil fuels is becoming the worldwide crisis in the years ahead. Besides the proper thermal and power performance, the compression ignition engines make lower greenhouse-gas emissions compared to the spark-ignition engines. Using dimethyl-ether (DME) as an environmentally friendly fuel in a diesel engine can improve its advantages. In the present paper, the effects of the piston bowl geometry in a DME-burning direct injection (DI) engine have been numerically evaluated. In order to enhance combustion and emission characteristics, various piston bowls with different bowl volumes are designed and examined. Furthermore, the influences of engine speed and compression ratio are further investigated. The results showed that lower bowl volume led to more air-fuel mixing. Reduction of the bowl volume size from 6.446e-005 m3 to 1.5282e-005 m3 caused reduction in emissions of the soot, NO and CO by 91%, 9.3%, and 99%, respectively (the exhaust CO2 concentration was almost identical for each piston bowls). in addition, lower compression ratio caused reduction in temperature and NO emissions. It is determined that amount of exhaust emissions is affected by increasing the engine speed, and mean pressure of the engine cylinder reduced, dramatically. It is found that taking advantage of DME fuel in the ISM 370 diesel engine caused reduction in the NO, soot, CO and CO2 by 75%, 20%, 8%, and 44.43%, respectively, under 1200 rpm engine speed.
- انتشار مقاله: 21-07-1397
- نویسندگان: Kianoosh Shojae,Majid Mahdavian
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Performance,Injection timing,Hydrogen addition,ISM 370 diesel engine,engine speed
- چکیده:
- چکیده انگلیسی: Hydrogen fuel is the cleanest fuel available. This fuel can be used as an additive in the diesel engine. Diesel engines have the advantages of strong power, high thermal efficiency and low fuel costs. There have been extensive studies on the use of hydrogen fuel in diesel engines in recent years. However, the simultaneous effect of using gaseous hydrogen fuel and changing injection strategy needs further investigation specially for the Cummins ISM370 engine. This work considers almost all functional and emission parameters, simultaneously. This procedure can be effective to achieve balanced conditions when 6% H2 (by volume) is injected into the Cummins ISM 370 diesel engine (under different engines). In addition, due to changing fuel compound used in engine, injection timing and temperature of engine should be redesigned to better operating. For simulation of engine, a CFD code was used. In order to validity and verify the simulation predicted mean pressure and the rate of heat release are compered to experimental data and results gave appropriate accordance. Results show that most of exhaust emissions such as NO, CO, etc. are dramatically reduced by using gaseous hydrogen under various engine speeds. It is determined that with addition of 6% H2 within the engine, indicated thermal efficiency is increased by around 39%; and NO, soot, CO and CO2 emissions are reduced by 5%, 75%, 70%, and 30%, respectively, under 1600 rpm speed. It is also found that the best injection timing that makes a balance between exhaust emissions and performance parameters is 4 deg BTDC under 2000 rpm. Moreover, the best injection temperature is 330 K among of three considered injection temperatures.3
- انتشار مقاله: 13-04-1396
- نویسندگان: Kianoosh Shojae,Majid Mahdavian
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: HD diesel engine,EGR,DME Fuel,piston bowl geometry,injection strategy
- چکیده:
- چکیده انگلیسی: The amount of pollutant gases in the atmosphere has reached a critical state due to an increase in industrial development and the rapid growth of automobile industries that use fossil fuels. The combustion of fossil fuels produces harmful gases such as carbon dioxide, nitrogen monoxide (NO), soot, particulate matter (PM), etc. The use of Dimethyl Ether (DME) biofuel in diesel engines or other combustion processes have been highly regarded by researchers. Studies show that the use of pure DME in automotive engines will be possible in the near future. The present work evaluated the environmental and performance effects of changing the injection strategy (time and temperature), piston bowl geometry, and exhaust gas recirculation (EGR) composition for a DME-burning engine. The modification of piston bowl parameters and engine simulation were numerically performed by using AVL fire CFD code. For model validation, the calculated mean pressure and rate of heat released (RHR) were compared to the experimental data and the results showed a good agreement (under a 70% load and 1200-rpm engine speed). It was found that retarding injection timing (reduction in in-cylinder temperature, consequently) caused a reduction in NO emissions and increased soot formation, reciprocally; this occurred because of a reduction in temperature and a lower soot oxidation in the combustion chamber. It became clear that 3 deg before top dead center (BTDC) was the appropriate injection timing for the DME-burning heavy duty diesel engine running under 1200 rpm. Also, the parametrical modification of the piston bowl geometry and the simultaneous decrease of Tm (piston bowl depth) and R3 (bowl inner radius) lengths were associated with lower exhaust NO emissions. For the perfect utilization of DME fuel in an HD diesel engine, the suggested proper lengths of Tm and R3 were 0.008 and 0.0079 m, respectively. Furthermore, various EGR compositions for the reduction of exhaust NO were investigated. The simulation results showed that a 0.2 EGR composition led to a reduction in the exhaust NO by 37%.
- انتشار مقاله: 16-05-1395
- نویسندگان: Kianoosh Shojae,Majid Mahdavian
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: HD diesel engine,Exhaust emissions,EGR,Injection timing,Methanol biofuel
- چکیده:
- چکیده انگلیسی: Methanol as a biofuel is an environmentally friendly substitute for pure diesel and can be obtained from biomasses. The use of biofuels such as methanol for the combustion process is associated with positive impacts on the environment. Using pure methanol or a blend of diesel/methanol fuel in motorized vehicles has been proposed by researchers. In this paper, pure methanol was injected into the combustion chamber of a ISM 370 HD diesel engine and the exhaust emissions were evaluated by using AVL FIRE CFD code software at four engine speeds (1200, 1400, 1600 and 1800 rpm). Additionally, the influences of EGR mass fraction and various injection timings were investigated. In order to validate the simulation results, in-cylinder mean pressure and rate of heat release (RHR) were compared with experimental data, and the results gave an acceptable agreement. The obtained results from the conducted simulation showed that the use of methanol fuel in the combustion chamber dramatically reduced the amount of exhaust emissions such as NO, soot, CO, and CO2 to 90%, 75%, 40%, and 26%, respectively. In addition, a mass fraction of EGR (20%) caused a reduction in the amount of exhaust NO to about 12%. It was determined that when a system is equipped with a fueling system at 3 deg before top dead center (BTDC), the exhaust NO and soot are reduced by 5.8% and 3%.
- انتشار مقاله: 17-03-1395
- نویسندگان: Kianoosh Shojae,Majid Mahdavian
- مشاهده