Study on combustion and emissions of a hydrous ethanol/gasoline dual fuel engine with combined injection. (1st February 2022)

• Record Type: Journal Article
• Authors: Li, Decheng; Yu, Xiumin; Du, Yaodong; Xu, Mingjia; Li, Yinan; Shang, Zhen; Zhao, Zhe
• Is Part Of: Fuel. Volume 309(2022)
• Publication Date: 2022-02-01
• Subjects: AFR air fuel ratio -- APmax crank angle corresponding to Pmax -- APN accumulation mode particle number -- BTDC before top dead center -- BMEP brake mean effective pressure -- BSHC brake specific hydrocarbons -- BSCO brake specific carbon monoxide -- BSNOx brake specific nitrogen oxides -- BSPN brake specific particle number -- BSTC best spark timing for COVimep -- C carbon -- CA crank angle -- CA 0–10 duration of crank angle from the spark timing to 10% of the energy of fuel released -- CA 10–90 duration of crank angle from 10% to 90% of the energy of fuel released -- CO carbon monoxide -- CO2 carbon dioxide -- COVimep coefficient of indicated mean effective pressure variation -- DI direct injection -- DIr direct injection ratio -- EDI ethanol direct injection -- GE gasoline/ethanol dual fuel -- GEW gasoline/hydrous ethanol dual fuel -- GEW5 gasoline/hydrous ethanol with 5%vol. water dual fuel -- GEW10 gasoline/hydrous ethanol with 10%vol. water dual fuel -- GEW15 gasoline/hydrous ethanol with 15%vol. water dual fuel -- GEW20 gasoline/hydrous ethanol with 20%vol. water dual fuel -- GPI gasoline port injection -- GPIr gasoline port injection ratio -- H hydrogen radical -- H2 hydrogen -- HC hydrocarbons -- HEDI hydrous ethanol direct injection -- H2O water -- IMEP indicated mean effective pressure -- MBT minimum advance for best torque -- Mport mass of gasoline when engine worked in combined injection mode -- Mgasoline mass of gasoline when engine worked in GPI mode -- NOx nitrogen oxides -- NPN nucleation mode particle number -- OH hydroxyl radical -- PN particle number -- PFI port fuel injection -- Pmax maximum value of the cylinder pressure curve -- SI spark ignition -- Tmax maximum average temperature in cylinder -- TDC top dead center -- Vwater volume of water -- Vanethanol volume of anhydrous ethanol -- ω water ratio in hydrous ethanol -- λ excess air ratio; Hydrous ethanol -- Combined injection -- Dual fuel -- Combustion -- Gasoline -- Emission; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2021.122004
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: The HEDI + GPI combined injection mode was proposed. Larger ω prolonged CA 0-10 and CA 10-90, decreased Tmax and Pmax. HEDI + GPI mode had better power performance than GPI and EDI + GPI mode. ω of 5% is best for CO and NOx emissions, 10% is best for PN emissions. Larger ω increased HC emissions and made the size of particles smaller. Abstract: Hydrous ethanol has lower cost and energy consumption during the production process than anhydrous ethanol. Many researchers used hydrous ethanol instead of anhydrous ethanol to manufacture hydrous ethanol-gasoline. The water ratio in hydrous ethanol (ω) determines the energy consumption in the production process of ethanol. However, no one researched the effects of different ω on combustion and emissions of hydrous ethanol-gasoline. So, we prepared five kinds of ethanol with different ω (0, 5%, 10%, 15%, 20% vol.) to research the effects of ω on combustion and emissions. This study adopted combined injection with hydrous ethanol direct injection plus gasoline port injection (HEDI + GPI). The engine speed was 1500 rpm, and λ was 1, the intake manifold absolute pressure was 48 kPa, the direct injection ratio was 20%, five spark timings varied from 5 °CA BTDC to 25 °CA BTDC. The results showed hydrous ethanol prolonged flame development and propagation duration, decreased Tmax and Pmax, delayed APmax. Water increased COVimep, but using hydrous ethanol at the reasonable spark timing would not significantly affect the stability. Meanwhile, when the spark timing was MBT, compared with GE (gasoline/anhydrous ethanol dual fuel) fuel, as ω in GEW (gasoline/hydrous ethanol dual fuel) fuels increased, torque and brake thermal efficiency improved by 1.69%, 1.13%, −0.01%, −0.77%; HC increased by 2.13%, 9.02%, 23.89%, 37.15%; CO decreased by 41.95%, 28.56%, 5.59%, 2.46%; NOx decreased by 10.10%, −0.75%, −0.17%, 4.18%; total PN emissions decreased by 24.07%, 69.57%, 36.34%, 32.45%. Meanwhile, more water caused the size of particles to drop, made particles smaller.