Investigation of Dual-Fuel Combustion by Different Port Injection Fuels (Neat Ethanol and E85) in a DE95 Diesel/Ethanol Blend Fueled Compression Ignition Engine

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Habib Gürbüz ◽  
Selim Demirtürk

Abstract This paper investigated the effect of different substitution ratios of neat ethanol (E100) and ethanol–gasoline blend E85 on in-cylinder combustion, engine efficiency, and exhaust emissions, in a dual-fuel diesel engine, using the ethanol–diesel blend (DE95). Experimental studies realized at 1400 rpm, 1600 rpm, and 1800 rpm engine speeds under constant engine load of 50% (20 Nm). For each engine speed, the injection timing of diesel and E95 fuels at 24 °CA bTDC kept constant while low-reactivity fuels (i.e., E100 and E85) substitution ratio changed in the range of 59–83%. The results showed that premixed fuels in different SRs have an impact on shaping engine emissions, ignition delay (ID), in-cylinder pressure, and heat-release rate. Also, at the dual-fuel experimental studies in all engine speeds, NOx about 47–67% decrease compared to single fuel conditions of reference diesel and DE95, and smoke opacity remained unchanged around 0.1 FSN, whereas HC and CO increased in the range of 20–50%. However, E85/DE95 and E100/DE95 dual-fuel combustion achieved lower brake thermal efficiency (BTE) and combustion efficiency compared to single diesel fuel combustion. On the other hand, in dual-fuel combustion conditions, despite the low combustion efficiency, premixed E85 fuel offered higher engine efficiency and lower exhaust emissions than E100.

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ismail Hakki Hakkı Akçay ◽  
Habib Gürbüz ◽  
Hüsameddin Akçay ◽  
Mustafa Aldemir

Purpose This study seeks the effect on static thrust, thrust specific energy consumption (TSEC) and exhaust emissions of euro diesel-hydrogen dual-fuel combustion in a small turbojet engine. Design/methodology/approach Experimental studies are performed in a JetCat P80-SE type small turbojet engine. Euro diesel and hydrogen is fed through two different inlets in a common rail distributing fuel to the nozzles. Euro diesel fuel is fed by a liquid fuel pump to the engine, while hydrogen is fed by a fuel-line with a pressure of 5 bars from a gas cylinder with a pressure of approximately 200 bars. Findings At different engine speeds, it is found that there is a decrease at the TSEC between a range of 1% and 4.8% by different hydrogen energy fractions (HEF). Research limitations/implications The amount of hydrogen is adjusted corresponding to a range of 0–20% of the total heat energy of the euro diesel and hydrogen fuels. The small turbojet engine is operated between a range of 35,000 and 95,000 rpm engine speeds. Practical implications On the other hand, remarkable improvements in exhaust emissions (i.e. CO, CO2, HC and NOx) are observed with HEFs. Originality/value This is through providing improvements in performance and exhaust emissions using hydrogen as an alternative to conventional jet fuel in gas turbine engines.


2021 ◽  
pp. 146808742110183
Author(s):  
Jonathan Martin ◽  
André Boehman

Compression-ignition (CI) engines can produce higher thermal efficiency (TE) and thus lower carbon dioxide (CO2) emissions than spark-ignition (SI) engines. Unfortunately, the overall fuel economy of CI engine vehicles is limited by their emissions of nitrogen oxides (NOx) and soot, which must be mitigated with costly, resource- and energy-intensive aftertreatment. NOx and soot could also be mitigated by adding premixed gasoline to complement the conventional, non-premixed direct injection (DI) of diesel fuel in CI engines. Several such “dual-fuel” combustion modes have been introduced in recent years, but these modes are usually studied individually at discrete conditions. This paper introduces a mapping system for dual-fuel CI modes that links together several previously studied modes across a continuous two-dimensional diagram. This system includes the conventional diesel combustion (CDC) and conventional dual-fuel (CDF) modes; the well-explored advanced combustion modes of HCCI, RCCI, PCCI, and PPCI; and a previously discovered but relatively unexplored combustion mode that is herein titled “Piston-split Dual-Fuel Combustion” or PDFC. Tests show that dual-fuel CI engines can simultaneously increase TE and lower NOx and/or soot emissions at high loads through the use of Partial HCCI (PHCCI). At low loads, PHCCI is not possible, but either PDFC or RCCI can be used to further improve NOx and/or soot emissions, albeit at slightly lower TE. These results lead to a “partial dual-fuel” multi-mode strategy of PHCCI at high loads and CDC at low loads, linked together by PDFC. Drive cycle simulations show that this strategy, when tuned to balance NOx and soot reductions, can reduce engine-out CO2 emissions by about 1% while reducing NOx and soot by about 20% each with respect to CDC. This increases emissions of unburnt hydrocarbons (UHC), still in a treatable range (2.0 g/kWh) but five times as high as CDC, requiring changes in aftertreatment strategy.


2020 ◽  
Vol 197 ◽  
pp. 06010
Author(s):  
Antonio Caricato ◽  
Antonio Paolo Carlucci ◽  
Antonio Ficarella ◽  
Luciano Strafella

In this paper, the effect of late injection on combustion and emission levels has been investigated on a single cylinder compression ignition engine operated in dual-fuel mode injecting methane along the intake duct and igniting it through a pilot fuel injected directly into the combustion chamber. During the tests, the amount of pilot fuel injected per cycle has been kept constant, while the amount of methane has been varied on three levels. Therefore, three levels of engine load have been tested, while speed has been kept constant equal to 1500rpm. Pilot injection pressure has been varied on three set points, namely 500, 1000 and 1500 bar. For each engine load and injection pressure, pilot injection timing has been swept on a very broad range of values, spanning from very advanced to very late values. The analysis of heat release rate indicates that MK-like conditions are established in dual-fuel mode with late pilot injection. In these conditions, pollutant species, and NOx levels in particular, are significantly reduced without penalization – and in several conditions with improvement – on fuel conversion efficiency.


2019 ◽  
Vol 21 (3) ◽  
pp. 484-496 ◽  
Author(s):  
Carlos Guardiola ◽  
Benjamín Pla ◽  
Pau Bares ◽  
Alvin Barbier

This work presents a closed-loop combustion control concept using in-cylinder pressure as a feedback in a dual-fuel combustion engine. At low load, reactivity controlled compression ignition combustion was used while a diffusive dual-fuel combustion was performed at higher loads. The aim of the presented controller is to maintain the indicated mean effective pressure and the combustion phasing at a target value, and to keep the maximum pressure derivative under a limit to avoid engine damage in all the combustion modes by cyclically adapting the injection settings. Various tests were performed at steady-state conditions showing good abilities to fulfil the expected operating conditions but also to reject disturbances such as intake pressure or exhaust gas recirculation variations. Finally, the proposed control strategy was tested during a load transient resulting in a combustion switching-mode and the results exhibited the closed-loop potential for controlling such combustion concept.


Sign in / Sign up

Export Citation Format

Share Document