Different exhaust temperature management technologies for heavy-duty diesel engines with regard to thermal efficiency. (5th March 2021)

• Record Type: Journal Article
• Authors: Wu, Binyang; Jia, Zhi; Li, Zhen guo; Liu, Guang yi; Zhong, Xiang lin
• Is Part Of: Applied thermal engineering. Volume 186(2021)
• Publication Date: 2021-03-05
• Subjects: VGT Variable Geometry Turbocharger -- RIVCT Retarded Intake Valve Closing Timing -- SCR Selective Catalytic Reduction -- DPF Diesel Particulate Filter -- BMEP Brake Mean Effective Pressure -- CA Crank Angle -- ATDC After Top Dead Center -- BSFC Brake Specific Fuel Consumption -- TDC Top Dead Center -- CA10 Crank Angle Of 10% Heat Release -- CA90 Crank Angle Of 90% Heat Release -- BTE Brake Thermal Efficiency -- ITEg Gross Indicated Thermal Efficiency -- WHTC World Harmonized Transient Cycle; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2020.116495
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: The effects of different technologies on exhaust temperature and fuel consumption are studied. Variable geometry turbocharger and variable valve actuation can improve the fuel efficiency by reducing the pumping losses. Thermal management technology can make SCR temperature reach 190 °C within 450 s in WHTC. Abstract: Driven by increasingly strict environmental protection regulations, advanced clean combustion and after-treatment technologies have been applied to diesel engines so as to achieve zero impact emissions. After-treatment systems can realize highly efficient conversion within a certain temperature range. Thermal management technology is important in rapidly improving the temperature in after-treatment systems. However, the traditional thermal management technology is characterized by the trade-off between thermal efficiency and exhaust gas temperature. On the basis of numerical simulations and experimental tests method on a heavy-duty diesel engine, this study investigated the potential of improving exhaust gas temperature from the aspects of fuel system and air system. Focus was directed toward the influence of intake throttle, exhaust throttle, intercooler cooling control, and variable geometry turbocharger (VGT)-coupled retarded intake valve closing timing technology (RIVCT) on exhaust gas temperature and thermal efficiency. Results showed that the VGT–RIVCT can improve thermal efficiency and exhaust gas temperature and effectively solve the trade-off problem of the traditional thermal management technology. In this study, we adopted thermal insulation, post-injection, and VGT–RIVCT, to achieve the temperature of selective catalytic reduction (SCR) system in the cold WHTC cycle reaching 190 °C in the 450th second, and significantly reduce NOx emissions.