Experimental investigation of the combustion characteristics and the emission characteristics of biogas–diesel dual fuel in a common-rail diesel engine

2017 ◽  
Vol 231 (14) ◽  
pp. 1900-1912 ◽  
Author(s):  
Yong Qian ◽  
Yahui Zhang ◽  
Xiaole Wang ◽  
Xingcai Lu
Keyword(s):  
Carbon Monoxide ◽  
Heat Release ◽  
Nitrogen Oxide ◽  
Release Rate ◽  
Exhaust Gas Recirculation ◽  
Dual Fuel ◽  
Emission Characteristics ◽  
Exhaust Gas ◽  
Nitrogen Oxide Emissions ◽  
Gas Recirculation

An experimental study on biogas–diesel dual-fuel compression ignition was conducted in which biogas and diesel are used as the port-injected fuel and the directly injected fuel respectively. The effects of the total lower heating values QLHVs per cycle and the premixed ratio on the combustion characteristics and the emission characteristics are discussed in detail. The results show that, for constant QLHVs, the peak values of the heat release rate curves first decrease and then increase with increasing premixed ratio. Furthermore, the combustion phase is delayed. For a constant premixed ratio, with increasing QLHVs, the heat release rate curves change from a unimodal distribution to a bimodal distribution, and the ignition delay decreases constantly. With higher QLHVs, the nitrogen oxide emissions and the smoke emissions are relatively higher. In addition, the impacts of biogases with different components on the combustion and emissions were also researched. With increasing hydrogen, the combustion becomes increasingly concentrated, which leads to higher nitrogen oxide emissions. The proportion of carbon monoxide in the biogas has a great effect on the carbon monoxide emissions. Also, the influence of exhaust gas recirculation was also studied. With 60% exhaust gas recirculation, the nitrogen oxide emissions can be inhibited effectively.

Gasoline engine performance simulation of water injection and low-pressure exhaust gas recirculation using tabulated chemistry

2020 ◽  
Vol 21 (10) ◽  
pp. 1857-1877 ◽  
Author(s):  
Tim Franken ◽  
Fabian Mauss ◽  
Lars Seidel ◽  
Maike Sophie Gern ◽  
Malte Kauf ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Nitrogen Oxide ◽  
Water Injection ◽  
Exhaust Gas Recirculation ◽  
Low Pressure ◽  
Exhaust Gas ◽  
Nitrogen Oxide Emissions ◽  
Direct Water Injection ◽  
Tabulated Chemistry ◽  
Gas Recirculation

This work presents the assessment of direct water injection in spark-ignition engines using single cylinder experiments and tabulated chemistry-based simulations. In addition, direct water injection is compared with cooled low-pressure exhaust gas recirculation at full load operation. The analysis of the two knock suppressing and exhaust gas cooling methods is performed using the quasi-dimensional stochastic reactor model with a novel dual fuel tabulated chemistry model. To evaluate the characteristics of the autoignition in the end gas, the detonation diagram developed by Bradley and co-workers is applied. The single cylinder experiments with direct water injection outline the decreasing carbon monoxide emissions with increasing water content, while the nitrogen oxide emissions indicate only a minor decrease. The simulation results show that the engine can be operated at λ = 1 at full load using water–fuel ratios of up to 60% or cooled low-pressure exhaust gas recirculation rates of up to 30%. Both technologies enable the reduction of the knock probability and the decrease in the catalyst inlet temperature to protect the aftertreatment system components. The strongest exhaust temperature reduction is found with cooled low-pressure exhaust gas recirculation. With stoichiometric air–fuel ratio and water injection, the indicated efficiency is improved to 40% and the carbon monoxide emissions are reduced. The nitrogen oxide concentrations are increased compared to the fuel-rich base operating conditions and the nitrogen oxide emissions decrease with higher water content. With stoichiometric air–fuel ratio and exhaust gas recirculation, the indicated efficiency is improved to 43% and the carbon monoxide emissions are decreased. Increasing the exhaust gas recirculation rate to 30% drops the nitrogen oxide emissions below the concentrations of the fuel-rich base operating conditions.

Investigation of a Generic Gas Turbine Combustor With Exhaust Gas Recirculation

2013 ◽  
Author(s):  
Sebastian Ulmer ◽  
Franz Joos
Keyword(s):  
Heat Release ◽  
Gas Turbine ◽  
Co2 Capture ◽  
Release Rate ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Nitric Oxides ◽  
Gas Turbine Combustor ◽  
A Minor ◽  
Gas Recirculation

On the topic of CO2 capture from gas turbines, exhaust gas recirculation (EGR) is a commonly discussed method to increase CO2 concentration at a gas turbine outlet to make the CO2 capture process more efficient. This paper presents the influence of the recirculation on heat release rate and emissions. The investigation is made using the commercial RANS solver ANSYS CFX coupled with an in-house code for a hybrid transported PDF/RANS simulation using detailed chemistry of GRI 3.0. Initially an investigation on reactivity was made using numerical calculation of laminar flame speed. It is found that exhaust gas recirculation has only a minor effect on reactivity in lean premixed combustion. Therefore, the operation point of the combustor can be kept constant with and without EGR. Simulations of the combustor with exhaust gas recirculation using the hybrid PDF/RANS with GRI 3.0 show a minor influence of NO and NO2 doping of the vitiated air on the flame speed and the doping delays heat release slightly. CO doping has no effect on heat release rate. CO emissions at combustor exit remain unaffected by NO, CO or NO2 doping. Seeding the vitiated air with 50ppm nitric oxides reveal that any NO2 present in the vitiated air is reduced to NO in the flame. NO2 emissions increase with NO2 doping but are still 2 magnitudes lower than NO emissions. It is found that NO is reduced by 3% due to of NO reburn. Based on literature data it is concluded that there is a deficit of the GRI 3.0 reaction mechanism. Experimental data taken from literature reveal of NO reburn by approximately 20%. Therefore emission data of nitric oxides of flames that should show a considerable reburn effect should be used with caution, while heat release and CO emissions are predicted more accurately. It is shown, that with the model created for the generic gas turbine combustor it is possible to study the effects of exhaust gas recirculation on the combustion process in detail and resolve detailed kinetic effects.

scholarly journals Effect of air preheating, exhaust gas recirculation and hydrogen enrichment on biodiesel/methane dual fuel engine

2020 ◽  
pp. 146-146
Author(s):  
Kavin Mohanasundaram ◽  
Nagarajan Govindan
Keyword(s):  
Carbon Monoxide ◽  
Thermal Efficiency ◽  
Exhaust Gas Recirculation ◽  
Waste Cooking Oil ◽  
Dual Fuel ◽  
Exhaust Gas ◽  
Oxides Of Nitrogen ◽  
Cooking Oil ◽  
Energy Share ◽  
Gas Recirculation

An experimental study was carried out to investigate the effect of intake air preheating, exhaust gas recirculation and hydrogen enrichment on performance, combustion and emission characteristics of Methane/waste cooking oil biodiesel fuelled compression ignition engine in dual fuel mode. Methyl ester derived from waste cooking oil was used as a pilot fuel which was directly injected into the combustion chamber at the end of the compression stroke. Methane/hydrogen-enriched methane was injected as the main fuel in the intake port during the suction stroke using a low pressure electronic port fuel injector which is controlled by an electronic control unit. The experiments were conducted at a constant speed and at the maximum load. Experimental results indicated that the increase in energy share of gaseous fuel extends the ignition delay. With air preheating the thermal efficiency increased to 49% and 55% of methane and hydrogen-enriched methane energy share respectively. Carbon monoxide and hydrocarbon emissions were higher in methane combustion with biodiesel when compared to the conventional diesel operation at full load and a reduction in carbon monoxide and hydrocarbon was observed with air preheating. Lower oxides of nitrogen were observed with gaseous fuel combustion and it further reduced with exhaust gas recirculation but oxides of nitrogen increased by preheating the intake air. Improvement in thermal efficiency with a reduction in hydrocarbon and carbon monoxide was observed with hydrogen-enriched methane.

A Detailed Study of the Effects of Biodiesel Addition and Exhaust Gas Recirculation on Diesel Engine PCCI Combustion, Performance and Emission Characteristics by KIVA–CHEMKIN Coupling

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Alborz Zehni ◽  
Rahim Khoshbakhti Saray ◽  
Elahe Neshat
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Exhaust Gas Recirculation ◽  
Emission Characteristics ◽  
Exhaust Gas ◽  
Performance And Emission ◽  
Combustion Performance ◽  
Temperature Heat ◽  
Dilution Effects ◽  
Gas Recirculation

In this study, a numerical study is performed by KIVA–CHEMKIN code to investigate the effects of biodiesel addition and exhaust gas recirculation (EGR) on diesel engine premixed charge compression ignition (PCCI) combustion, performance, and emission characteristics. The studies are performed for neat diesel fuel and mixture of 10–40% biodiesel addition at 67%, 50%, and 40% EGR. For this purpose, a multichemistry surrogate mechanism using methyl decanoate (MD) and methyl-9-decenoate (MD9D) is used. The main innovation of this work is analyzing the chemical, thermodynamic, and dilution effects of biodiesel addition as well as different EGR ratios on PCCI combustion behavior. The results show that the main effect of EGR on PCCI combustion of biodiesel blend is related to the high temperature heat release (HTHR), and its effect on low temperature heat release (LTHR) is low. With increasing biodiesel addition, the role of the chemical effect is increased compared to the thermodynamic and dilution effects. Rate of production analysis (ROPA) indicate that for the different biodiesel ratios, the effect of reaction nC7H16 + HO2 = C7H15-2 + H2O2 is more effective on the start of combustion (SOC) compared to the other reactions. For a defined biodiesel addition, with decreasing EGR, total (unburned) hydrocarbon (THC) and CO are decreased, while NOx and indicated specific fuel consumption (ISFC) are increased.

Performance, Combustion and Emission Characteristics of a Common Rail Direct Injection Diesel Engine Fueled by Diesel/n-Amyl Alcohol Blends with Exhaust Gas Recirculation Technique

2021 ◽  
pp. 1-27
Author(s):  
Ramachander J ◽  
Santhosh Kumar Gugulothu
Keyword(s):  
Nitrogen Oxide ◽  
Diesel Fuel ◽  
Direct Injection ◽  
Exhaust Gas Recirculation ◽  
Amyl Alcohol ◽  
Common Rail ◽  
Exhaust Gas ◽  
Nitrogen Oxide Emissions ◽  
Gas Recirculation ◽  
Conventional Diesel Fuel

Abstract Biofuels are considered as one of the best viable and inexhaustible alternatives to conventional diesel fuel. Alcohols have become very important and popular in the present scenario due to their peculiar fuel properties and production nature. This study examines the effect of n-amyl alcohol and exhaust gas recirculation of 10% and 20% on various engine characteristics of Common Rail Direct Injection (CRDI) compression ignition engine. The proportion of n-amyl alcohol varies from 5% to 25% in 5% step (by volume). The obtained results show that diesel/n-amyl alcohol blends decrease the mean gas temperature and cylinder pressure, which is 1.88% and 4.25% less at 75% load for n-amyl alcohol (25%) with conventional diesel fuel. The duration of combustion has shown a hike of 4.66°CA for 25% n-amyl alcohol (at 75% load) compared to conventional diesel fuel. However, the cumulative heat release rate improved by 12.95% higher for 25% n-amyl alcohol at 75% load, the reason for the same is due to the extended delay in ignition. While n-amyl alcohol was used, the emission of nitrogen oxide emissions decreased considerably. However, the hydrocarbon (HC) (7-9%) and carbon monoxide (CO) (6-8%) emissions are increased due to inferior fuel properties like high latent heat evaporation of n-amyl alcohol. Compared with other blends, n-amyl alcohol (5%) produced results comparable to conventional diesel fuel, which is 3.6% higher in BSFC, 2.37 % higher BTE, and 33.33% higher CO emissions 18.18% more in HC emission, and 17.55% less NOx emission. Without further modification, we can use 25% n-amyl alcohol in the combustion ignition engines. From this evidence, we can summarize that n-amyl alcohol is a biofuel that is both renewable and sustainable, and also it considerably reduces harmful nitrogen oxide emissions. The performance, if needed, can be improved by changing the parameters of the engine.

Advantages of using a cooler bypass in the low-pressure exhaust gas recirculation line of a compression ignition diesel engine operating at cold conditions

2020 ◽  
pp. 146808742091472
Author(s):  
José Galindo ◽  
Vicente Dolz ◽  
Javier Monsalve-Serrano ◽  
Miguel Angel Bernal Maldonado ◽  
Laurent Odillard
Keyword(s):  
Diesel Engine ◽  
Nitrogen Oxide ◽  
Low Temperatures ◽  
Cold Start ◽  
Exhaust Gas Recirculation ◽  
Low Pressure ◽  
Exhaust Gas ◽  
Nitrogen Oxide Emissions ◽  
Warm Up ◽  
Gas Recirculation

The low efficiency of the after-treatment systems during the cold start period of the internal combustion engines leads to excessive pollutant emissions levels. To reduce the nitrogen oxide emissions at these conditions, it could be necessary to use the high- and low-pressure exhaust gas recirculation strategies, even operating at low temperatures. This article evaluates the impact of using a low-pressure exhaust gas recirculation cooler bypass in a Euro 6 turbocharged diesel engine running under cold conditions (–7 °C). A new compact line fitted with a bypass system for the cooler is used with the aim of accelerating the engine warm-up process as compared to the original low-pressure exhaust gas recirculation line. The system is evaluated following two strategies, first performing exhaust gas recirculation without bypass and then performing exhaust gas recirculation bypassing the cooler. The results show that the activation the low-pressure exhaust gas recirculation from the engine cold start leads to a significant nitrogen oxide emissions reduction. Moreover, the bypass activation leads to increase the engine intake temperature, reducing the engine warm-up time and the CO emissions due to better combustion efficiency. However, the activation of the low-pressure exhaust gas recirculation at low temperatures could produce condensation and fouling deposits on the engine components affecting their life span. These phenomena are visualized using endoscope cameras in order to identify the condensation time and the final conditions of the elements. In addition, a chemical analysis of some condensates collected during the experiments and a comparison versus other species found in the literature is presented.

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