Maximum Heat Release Rate Research Articles

Combustion Characteristics of Single Cylinder Diesel Engine Fueled with Blends of Thumba Biodiesel as an Alternative Fuel

The rapid rise in energy requirement and problem regarding atmosphere pollutions, renewable biofuels are the better alternative choice for the internal combustion engine to partially or totally replace the pollutant petroleum fuel. In the present work, thumba (Citrullus colocynthis) non-edible vegetable oil is used for the production of biodiesel and examine its possibility as diesel engine fuel. Transesterification process is used to produce biodiesel from thumba non-edible vegetable oil. Thumba biodiesel (TBD) is used to prepare five different volume concentration (blends) with neat diesel (D100), such as TBD5, TBD15, TBD25, TBD35 and TBD45 to run a single cylinder diesel engine. The diesel engine's combustion parameter such as in-cylinder pressure, rate of pressure rise, net heat release rate, cumulative heat release, mean gas temperature, and mass fraction burnt analyzed through graphs and compared all thumba biodiesel blends result with neat diesel fuel. The mass fraction burnt start earlier for thumba biodiesel blends compared to diesel fuel because of less ignition delay while peak in-cylinder pressure, maximum rate of pressure rise, maximum net heat release rate, maximum cumulative heat release, and maximum mean gas temperature has found decreased results up to 1.93%, 5.53%, 4.11%, 4.65%, and 1.73% respectively for thumba biodiesel.

Experimental study on the variation regimes of window ejecting flame height

The fast growth of window ejecting flame height has long been thought to be influenced by the vertical wall via partially blocking air entrainment on the by-wall side. In the present research, experiments were conducted by employing a reduced scale compartment-façade model to examine this view and study the factors leading to the fast flame height growth. The inner size of the compartment was 0.4 m (W) by 0.6 m (L) by 0.4 m (H). A 0.2 m by 0.2 m square propane burner was employed as a fire source. Flame height in cases with and without vertical wall were compared. It was shown that in cases both with and without vertical wall, the flame height underwent a rapid growth with increase of heat release rate (HRR) Q when 1.8≤Q/Qc≤2.5, where Qc is the theoretical maximum HRR inside the compartment and Q/Qc is a dimensionless HRR. The rapid growth of flame height was mainly caused by the increase of combustion efficiency rather than the vertical wall. The growth of flame height showed a power-law dependence on Q/Qc. The power index was 0.8, 2.5, and 0.8 for the ranges 1≤Q/Qc≤1.8, 1.8≤Q/Qc≤2.5, and Q/Qc≥2.5 respectively.

The effects of exhaust gas re-circulation and injection timing on combustion performance and emissions of biodiesel and its blends with 2-methylfuran in a diesel engine

In this study, the influences of injection timing and exhaust gas re-circulation on combustion and emissions characteristics of biodiesel/2-methylfuran blends are investigated on a modified water-cooled 4-cylinder four-stroke direct injection compression ignition engine. The experimental conditions are, respectively, to adjust injection timing and exhaust gas re-circulation ratio at 0.38 MPa break mean effective pressure with the engine speed at 1800 rpm constantly. With injection timing in advance, the peak cylinder pressure rose while maximum heat re-lease rate first decreased and next slightly raised. Ignition delay and brake specific fuel consumption reduced first and then raised while combustion duration and break thermal efficiency had the opposite trend. The NOx emissions in-creased, and HC emissions first reduced significantly and then slightly increased, while 1,3-butadiene and acetaldehyde emissions presented a reduction tendency. As exhaust gas re-circulation ratio increased gradually, ignition delay as well as combustion duration was prolonged. brake specific fuel consumption increased and break thermal efficiency declined. HC, CO, 1,3-butadiene, and acetaldehyde emissions raised while NOx emissions reduced significantly. Biodiesel could be-have well in a Diesel engine and thus a feasible alternative fuel for diesel. More-over, methylfuran addition into biodiesel could raise break thermal efficiency and the break thermal efficiency of BM20 is higher than BM10. However, both BM10 and BM20 appeared a combustion deterioration when injection timing at 2.5?CA before top head center.

Impact of Pentanol Addition and Injection Timing on the Characteristics of a Single-Cylinder Diesel Engine

In this study, first, the effects of addition of 10% (Pen10), 20% (Pen20), and 30% (Pen30) pentanol on the performance, combustion, and emissions of a diesel engine were investigated. Then, the effect of injection timing for Pen30 fuel was investigated by changing the original injection timing of 20 to 22 and 24° BTDC (before top dead center). The engine tests were performed under different loads at 2400 rpm. The results indicated that, with the advancing of the diesel injection timing and increasing the pentanol ratio in the fuel blends, the ignition delay increased and the start of combustion delayed. The maximum heat release rate and cylinder pressure values of pentanol blends were found to be higher than those of diesel fuel. Both the maximum cylinder pressure and the maximum heat release rate increased with the advancing of the diesel injection timing to 22 and 24° BTDC. Brake-specific fuel consumption value of Pen30 was higher than that of diesel fuel at the original injection timing, and it decreased as the injection timing was advanced to 22 and 24° BTDC as compared to that of the original injection timing. NOx emission decreased with the increasing pentanol fraction. Also, NOx emissions increased significantly at 24° BTDC injection timing but decreased slightly at 22° BTDC injection timing. Smoke emissions of the pentanol blends are lower than those of the diesel fuel under all operating conditions as well as decreased with the advancing injection timing.

Comparison of hydrogenated vegetable oil and biodiesel effects on combustion, unregulated and regulated gaseous pollutants and DPF regeneration procedure in a Euro6 car

The effects of traditional biodiesel (fatty acid methyl-esters, FAME) and a hydrotreated vegetable oil (HVO) were comprehensively investigated on a production Euro 6 diesel car, including fuel injection rate and timing, combustion analysis, emissions of regulated and unregulated pollutants, and regeneration of the diesel particle filter. The use of both biofuels is a part of the efforts to reduce emissions of greenhouse gases and health-relevant pollutants and to improve energy security and sustainability. HVO, albeit more expensive, offers benefits relative to FAME in terms of oxidation stability, injector fouling, energy content and cetane number. The car was fitted with an on-board instrumentation and subjected to a range of driving cycles on a chassis dynamometer. The fuel consumption calculated from instantaneous emissions data based on exhaust gas composition measured by an on-board FTIR and calculated exhaust flow matched directly measured fuel consumption within several percent on all fuels; differences in the consumption among the fuels correspond to different heating values. The combustion onset and maximum heat release rate were comparable for diesel and FAME but were advanced on HVO due to its higher cetane number, causing, at times, multiple distinct heat release peaks, suggesting that optimization of fuel injection timing for HVO might be beneficial. Emissions of methane and ammonia were negligible, of N2O were measurable and slightly lower for HVO than for other fuels, of formaldehyde were limited to cold engine accelerations and highest for FAME and negligible for HVO, of NO and NO2 were high on all fuels during all operating conditions except for the type approval test. The results confirm several relative advantages of HVO over RME, with penetration into engine lubricating oil during particle filter regeneration to be further investigated. The effects of HVO lubricity and other long-term effects were not evaluated here.

Effect of fuel injection pressure on the characteristics of single cylinder diesel engine powered by butanol-diesel blend

In the case of the use of an alternative fuel in an engine, some changes in engine operating parameters may be required to achieve the same or higher engine performance. Fuel injection pressure is one of the most important operating parameters effecting the characteristics of diesel engines. In this study, the impact of fuel injection pressure on combustion, engine performance and exhaust emission of a single cylinder diesel engine fueled with butanol-diesel fuel blend was examined. The test results indicated that butanol-diesel blend (Bu10) started injection earlier than diesel fuel and had a longer ignition delay and shorter combustion duration. Ignition delay and combustion duration decreased with the increasing of injection pressure. The higher cylinder pressure and heat release rate peaks for Bu10 were obtained due to the rapid burning of the accumulated fuel in the cylinder during longer ignition delay. With increasing injection pressure, the maximum cylinder pressure and heat release rate increased. As the engine speed increased, the maximum cylinder pressure and heat release rate decreased. Brake thermal efficiency increased while brake specific fuel consumption decreased as fuel injection pressure decreased. In addition, Bu10 blend caused slightly higher brake thermal efficiency and brake specific fuel consumption. Bu10 blend caused a decrease smoke emission while slight increase NOx emissions. As the fuel injection pressure increased, NOx emission increased while smoke emission decreased because of the smaller diameter of the injected fuel droplets and better mixing of air with fuel.

Experimental investigation the impacts of injection strategies coupled with gasoline/ethanol blend on combustion, performance and emissions characteristics of a GDI spark-ignition engine

The injection timing under single injection strategy and double injection strategy consisting of an optimal timing for the first injection and a later timing for the second injection were investigated on a turbocharged GDI engine fuelled with gasoline and ethanol blend under stoichiometric air/fuel ratio. The combustion phasing, performance and emissions characteristics were comprehensively analyzed. The results indicated that the peak combustion pressure, maximum heat release rate and maximum in-cylinder temperature first increased and then decreased with sweeping the injection timing from 340 °CA bTDC to 280 °CA bTDC, reaching a peak value at 300 °CA bTDC. While the peak combustion pressure, maximum heat release rate and the maximum in-cylinder temperature gradually decreased with decreasing the percentage of first fuel injection distribution. In addition, the 50% combustion location was gradually stayed away from the top dead center, the combustion duration was prolonged, and the gasoline equivalent brake thermal efficiency decreased with decreasing the percentage of the first fuel distribution. Moreover, the injection timing under single injection strategy had no apparent impact on the COVIMEP. However, the fuel distribution under double injection strategy remarkably affected the COVIMEP. Lastly, the concentration of the HC increased with decreasing the percentage of the first fuel injection distribution. While the NOX emissions decreased with decreasing the percentage of the first fuel injection distribution.

Numerical Investigation on Performance and Emission Characteristics of a Diesel Engine Fired With Methanol Blended Diesel Fuel

The effects of methanol and oleic acid blended diesel fuel on the performance and emissions of the diesel engine are evaluated numerically by commercial software Diesel-RK to simulate a single cylinder, naturally aspirated, direct injection, four-stroke diesel engine. The present study also resolves the problem of the immiscibility of methanol in diesel fuel, as to avoid immiscible nature an optimum percentage of oleic acid and n-butanol is added to make blends stable. The methanol blended diesel fuels are 7%, 12%, and 17% methanol in volume basis (D85M7NB1O7, D75M12NB1O12, and D65M17NB1O17). A drastic reduction in NOx emission is observed due to low combustion temperature however the PM emissions increases which can be controlled by using exhaust after-treatment techniques. The results indicate that: the brake specific fuel consumption increases and brake thermal efficiency decreases with an increase of methanol, oleic acid and n-butanol contents in the blended fuel whereas maximum heat release rate increases and exhaust temperature decreases.

Characterization of Engine Performance, Combustion Process and Emission of Diesel/CNG Dual Fuel Engines with Pilot Injection Timing Variation at Low Load

The use of CNG on dual fuel diesel engines causes a decrease in engine performance, combustion and increased emissions, especially at low loads, which is affected by the addition of ignition delay period so that the maximum of peak combustion away from the top dead center (TDC). Pilot injection timing acts as an ignition delay controller. This research was carried out using an experimental method on diesel/CNG dual fuel engine a single-cylinder to determine the engine performance, combustion process and emissions characteristics with a variation of pilot injection timing from 110 to 190 BTDC with an interval of 20. The results showed an increase in thermal efficiency of 3.006%, maximum cylinder pressure up to 4.78 MPa, maximum heat release rate of up to 52.05 kJ/m3/0CA, and decrease hydrocarbons (HC), carbon dioxide (CO) and particulate matter (PM) emissions at pilot injection timing 170 BTDC under low load. Likewise, combustion performance has increased marked by a reduction in combustion duration and maximum of peak combustion approaching TDC by advancing the pilot injection timing on diesel/CNGdual fuel engine.

Synthesis of carborane acrylate and flame retardant modification on silk fabric via graft copolymerization with phosphate‐containing acrylate

SummaryA novel carborane acrylate monomer (1‐acryloyloxyethyl carborane) was synthesized by addition reaction, hydrolysis, and esterification and characterized by proton nuclear magnetic resonance (1H NMR) spectroscopy and Fourier transform infrared spectroscopy (FT‐IR) analysis. Subsequently, the carborane monomer and a phosphate‐containing methacrylate monomer were applied on the modification of a silk fabric. The heat resistance and flame retardancy of the silk fabric before and after modification were compared. Energy‐dispersive X‐ray spectrometer (EDS) and FT‐IR showed that carborane monomer and phosphate‐containing methacrylate were grafted onto the surface of the fibers. The cross‐sectional morphology of silk fabrics after burning was observed by scanning electron microscope (SEM), and the flame‐retardant mechanism was analyzed. Thermal‐gravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis revealed that the thermal stability of the modified silk increased with the increase of the grafting yield. The MCC‐2 microcalorimeter (MCC) test showed that, when using 1‐acryloyloxyethyl carborane as monomer and blending with phosphate‐containing methacrylate, the maximum heat release rate (PHRR) of the modified silk fabric decreased from 97.6 W/g (before grafting) to 51.3 and 45.8 W/g, respectively, and the total heat release (THR) decreased from 10.2 kJ/g (before grafting) to 5.9 and 5.2 kJ/g, respectively. The limiting oxygen index (LOI) test revealed that using 1‐acryloyloxyethyl carborane and phosphate‐containing methacrylate as mixed monomers to modify the silk fabric obtained good flame retardancy, whose LOI value reached 29.8%.

Numerical investigation on the effects of valve timing on in-cylinder flow, combustion and emission performance of a diesel ignition natural gas engine through computational fluid dynamics

In the present study, a diesel engine was modified to a diesel pilot ignited natural gas engine and the influences of intake valve closing timing on in-cylinder flow, combustion and emission performance of engine were investigated by three-dimensional computational fluid dynamics simulation. Based on the geometric model and basic parameters of this engine, the simulation model was built under three operating conditions and then validated by experimental data. On this basis, the validated model was applied to investigate the effects of the intake valve closing timing strategy. The simulation results indicated that, the volumetric efficiency decreases with the retarding of intake valve closing timing in three cases while it increases as the intake valve closing timing is advanced by 10°CA at 1200 rpm. The in-cylinder turbulence kinetic energy decreases with the retarding of intake valve closing timing. The peak in-cylinder pressure decreases when the intake valve closing timing is either advanced or retarded at 50% load. Nevertheless, the maximum peak in-cylinder pressure occurs at advancing 10°CA intake valve closing timing at 1200 rpm and 100% load, which rises by 4.5 bar compared with that at the original intake valve closing timing. Additionally, the maximum heat release rate appears at advancing 10°CA intake valve closing timing at 100% load, which is 26 J/deg higher than that at the original intake valve closing timing. Simultaneously, the shortest combustion duration occurs at advancing 10°CA intake valve closing timing at 1200 rpm and 100% load. For the emissions, the NOx emissions decrease with the retarding of intake valve closing timing but the variation becomes unobvious with the advancing of the intake valve closing timing. Besides, the intake valve closing timing strategy has little effect on HC and CO emissions.

Combustion and emission characteristics investigation of diesel-ethanol-biodiesel blended fuels in a compression-ignition engine and benefit analysis

This study has investigated feasibility to use ethanol in a compression ignition engine by blending it with diesel fuel, called diesohol. Additionally, biodiesel, acting as a co-solvent, is mixed into diesohol to prevent phase separation. Three blended ratios including B3E5, B7E5 and B10E10 were selected to conduct fuel property analysis and the engine test. In addition, commercial diesel in Thailand (B7) was used as a referent fuel. A commercial diesel engine with common rail fuel system was used to measure engine performance, fuel consumption, exhaust gas emissions including aldehydes as well as combustion characteristics. Benefits of using the diesohol fuel in pickup truck were also investigated.The results showed that with increasing ethanol fraction, the biodiesel fraction needed to be increased to prevent phase separation. When ambient temperature was decreased the phase separation could easily occur. Engine torque and power decreased when percentage of ethanol increased. In-cylinder pressure analysis showed that pilot combustion was moderated and retarded due to higher heat of vaporization of ethanol. With ethanol fraction increasing, the blended fuels required more time to evaporate, induced to higher heat release rate due to long ignition delay. Hydrocarbon emission was increased with longer period of fuel vaporization and mixing processes while the nitrogen oxide increased with increasing of maximum heat release rate. However, the diesohol can help facilitate biofuel market management by increasing biofuel (both ethanol and biodiesel) from diesel sector. In addition, fossil fuel will be suppressed and global warming impacts will be mitigated with diesohol supported measures.

Numerical investigation of the effects of inlet valve closing temperature and exhaust gas recirculation on the performance and emissions of an RCCI engine

In this paper, the effects of inlet valve closing temperature (TIVC) and exhaust gas recirculation (EGR) on the emissions and the performance of a reactivity controlled compression ignition (RCCI) engine have been numerically investigated. The numerical results were obtained for TIVC variations from 293 to 353 K and the EGR variations from 0 to 25%. For this purpose, the natural gas was injected in inlet port as a low reactivity fuel, while the diesel fuel was directly injected in the cylinder as a high reactivity fuel. For the numerical simulation validation, the results were compared to the reference data. The comparison shows that the in-cylinder pressure, rate of heat release (RoHR), soot and nitrogen oxide (NOx) emissions results are in good agreement with the reference data. According to the results, with increasing the EGR, the maximum in-cylinder pressure and also the maximum RoHR will be decreased. Moreover, increasing the EGR can considerably reduce NOx and soot emissions. When EGR increases from 0 to 25%, the NOx emission decreases from 0.47 to 0.02 g kW−1 h−1, while soot decreases from 0.009 to 0.0005 g kW−1 h−1. Also, increasing the TIVC will significantly increase the maximum pressure, RoHR and NOx and soot emissions. When TIVC increases from 293 to 353 k, the NOx emission increases from 0.01 to 0.41 g kW−1 h−1 and also soot from 0.0005 to 0.011 g kW−1 h−1. Finally, the results show that both of the TIVC and the EGR play important roles in controlling the combustion phase of an RCCI engine.

Experimental Investigation on Large Scale Diesel Pool Fire in a Vertically Ventilated Compartment

An experiment was performed for pool diameter 1 m located at the center of a compartment which has a size of 4 m x 4 m x 4 m (l x w x h). The door size was 2 m x 1 m (Height x Width) which was fully open during the experiment. The purpose of experiment was to obtain a data of burning characteristic of diesel fuel within the compartment. The large scale heat release calorimeter measure the heat release rate (HRR) and concentration of O2, CO2& CO. The thermocouple arrays are installed at different places to measure the ceiling temperatures; centerline temperatures above the pool, doorway temperatures.The maximum HRR has found 1 MW and during steady period average hot gas layer temperature reaches to 400 0C. The average mass burning rate was maintained to 0.037 kg/m2s, which was compared with other previous conducted experiments for diesel pool fire.

Chemiluminescence usage in finding optimum operating range of multi-hole burners

In the present study, chemiluminescence analysis is used to determine the optimum range for equivalence ratio (Φ) in a multi-hole cylindrical burner. The premixed burner which uses natural gas is widely applied in gas condensing boilers and is examined here by Flame Emission Spectroscopy (FES). A spectrometry setup was implemented to capture emission of the burner, in order to detect OH*, CH*, C2*, and CO2* species by their chemiluminescence. The emission of OH* and CO2* was investigated for different equivalence ratios and burner power showing a peak in the lean ranges of Φ = 0.77–0.85 and 0.78–0.85 respectively, that corresponds to the maximum heat release rate. In addition, the OH*/CH* intensity ratio was investigated for range of Φ = 0.6–1.2 for all burner power, resulting in a power independent relation for OH*/CH*. It can be used as a tool to derive equivalence ratio from the OH*/CH* ratio. Moreover, the maximum surface temperature of the burner in power range occurred at Φ = 0.82 in a promising agreement with chemiluminescence peaks of OH* and CO2*. The main contribution is to find the optimum range of equivalence ratio corresponding to the maximum heat release rate.

Experimental study of the spray, combustion, and emission performance of a diesel engine with high n-pentanol blending ratios

n-Pentanol exhibits some advantageous fuel properties, such as a higher energy density, lubricity, viscosity, and low hygroscopicity, when compared to short-chain alcohols. It is miscible with pure diesel in large proportions and burns directly on diesel engines. Therefore, n-pentanol is considered to be a promising diesel fuel additive. However, the differences between the chemical and physical properties of n-pentanol and commercial diesel affect the spray, combustion, and emissions performance of commercial diesel engines. In this study, visualization and engine experimental test methods were used to study the spray, combustion, and emissions performance of diesel/n-pentanol mixtures. The results showed that the atomization characteristics of diesel/n-pentanol mixtures were better than those of diesel. As the engine load increased, the maximum in-cylinder pressure and heat release rate increased. The brake specific fuel consumption (BSFC), nitrogen oxide (NOX), hydrocarbons (HC), and carbon monoxide (CO) emissions decreased, but soot emissions increased. Compared to diesel fuel, adding n-pentanol to pure diesel resulted in a decrease in soot emissions, while the BSFC, HC, and NOX emissions increased. Upon adding 50% n-pentanol to pure diesel (P50), the soot emissions decreased by up to 77.15% and the brake thermal efficiency (BTE) decreased by 1.86%. In summary, P50 could be burned directly on the diesel engine without any modifications, which can significantly reduce soot emissions; in this case, the BTE experienced only a slight decrease.

Experimental Study on the Fire-Spreading Characteristics and Heat Release Rates of Burning Vehicles Using a Large-Scale Calorimeter

In this article, large-scale experimental studies were conducted to figure out the fire characteristics, such as fire-spreading, toxic gases, and heat release rates, using large-scale calorimeter for one- and two-vehicle fires. The initial ignition position was the passenger seat, and thermocouples were attached to each compartment in the vehicles to determine the temperature distribution as a function of time. For the analysis, the time was divided into sections for the various fire-spreading periods and major changes, e.g., the fire spreading from the first vehicle to the second vehicle. The maximum temperature of 1400 °C occurred in the seats because they contained combustible materials. The maximum heat release rates were 3.5 MW and 6 MW for one and two vehicles, respectively. Since the time to reach 1 MW was about 240 s (4 min) before and after, the beginning of the car fire appears to be a medium-fast growth type. It shows the effect on the human body depending on the concentration of toxic substances such as carbon monoxide or carbon dioxide.

Study of the Effects of Biofuel-Oxygen of Various Origins on a CRDI Diesel Engine Combustion and Emissions

The paper presents the effects made by a fossil diesel–HRD (Hydrotreated Renewable Diesel) fuel blend containing Ethanol (E) or Biodiesel (B) on the combustion process, Indicated Thermal Efficiency (ITE), smoke, and pollutant emissions when running a turbocharged Common Rail Direct Injection (CRDI) engine under medium (50% of full load), intermediate (80% of full load), and full (100%) loads at maximum torque speed of 2000 rpm. These loads correspond to the respective Indicated Mean Effective Pressures (IMEP) of 0.75, 1.20, and 1.50 MPa, developed for the most common operation of a Diesel engine. The fuel-oxygen mass content was identically increased within the same range of 0 (E0/B0), 0.91 (E1/B1), 1.81 (E2/B2), 2.71 (E3/B3), 3.61 (E4/B4), and 4.52 wt% (E5/B5) in both E and B fuel groups. Nevertheless, these fuels still possessed the same blended cetane number value of 55.5 to extract as many scientific facts as possible about the widely differing effects caused by ethanol or biodiesel properties on the operational parameters of an engine. Both quantitative and qualitative analyses of the effects made by the combustion of the newly designed fuels with the same fuel-oxygen mass contents of various origins on the engine operational parameters were conducted comparing data between themselves and with the respective values measured with the reference (‘baseline’), oxygen-free fuel blend E0/B0 and a straight diesel to reveal the existing developing trends. The study results showed the positive influence of fuel-oxygen on the combustion process, but the fuel oxygen enrichment rate should be neither too high nor too low, but just enough to achieve complete diffusion burning and low emissions. The Maximum Heat Release Rate (HRRmax) was 3.2% (E4) or 3.6% (B3) higher and the peak in-cylinder pressure was 4.3% (E3) or 1.1% (B5) higher than the respective values the combustion of the reference fuel E0/B0 develops under full load operation. Due to the fuel-oxygen, the combustion process ended by 7.3° (E4) or 1.5° crank angle degrees (CADs) (B4) earlier in an engine cycle, the COV of IMEP decreased to as low as 1.25%, the engine efficiency (ITE) increased by 3.1% (E4) or decreased by 2.7% (B3), while NOx emissions were 21.1% (E3) or 7.3% (B4) higher for both oxygenated fuels. Smoke and CO emissions took advantage of fuel-oxygen to be 2.9 times (E4) or 32.0% (B4) lower and 4.0 (E3) or 1.8 times (B5) lower, respectively, while THC emissions were 1.5 times (E4) lower or, on the contrary, 7.7% (B4) higher than the respective values the combustion of the fuel E0/B0 produces under full load operation. It was found that the fuel composition related properties greatly affect the end of combustion, exhaust smoke, and pollutant emissions when the other key factors such as the blended cetane number and the fuel-oxygen enrichment rates are the same in both fuel groups for any engine load developed at a constant (2000 rpm) speed.

Investigation of combustion and emission characteristics of n-hexane and n-hexadecane additives in diesel fuel

One of the most important basic requirements of diesel-powered vehicles that they have lower pollutant emissions and fuel consumption. In diesel engines, combustion and engine performance are influenced by the physical and chemical properties of the used fuel. Engine design studies are not enough to increase engine performance and reduce exhaust emissions alone. By adding fuel additives in diesel fuel, the physical and chemical properties of the fuel can be improved. Fuel additives affect engine performance, combustion and emissions positively by exerting catalyst effect during combustion. In this study, n-hexane and n-hexadecane were added in diesel fuel (D0) by volume of 4, 12 % and 20 %. With respect to D0 fuel, in DHD20 and DHX20 fuels engine torque increased by 1.60 % and 1.32 %, respectively, while the brake specific fuel consumption decreased by 3.12 % and 1.98 %, respectively. Maximum cylinder pressures and heat release rate values of the ingredient added fuels increased. It was seen that NOx emissions increased while HC, CO and soot emissions decreased with increasing contribution ratio.

Synthesis and comprehensive study on industrially relevant flame retardant waterborne polyurethanes based on phosphorus chemistry

A series of novel industrially relevant halogen-free flame retardant self-curable silanized waterborne polyurethane (WPU) coatings were successfully synthesized. The effect of reactive-type phosphorus flame retardant diol (Exolit® OP560) incorporation into PU structure was investigated. High limit oxygen index (LOI) value of 30.4% accompanied by V0 classification of UL-94 vertical burning test confirmed promising flame retardancy of the WPU film containing 8.7 wt% OP560. Furthermore, microscale combustion calorimeter (MCC) indicated the obvious decrease in the heat release rate (HRR), the temperature of maximum HRR, total HR, and HR capacity (HRC) of WPUs by adding phosphorus diol. TGA, SEM, MCC, and TG-IR studies revealed that great improvement in flame retardancy was due to not only integral char formation through the synergistic effect of phosphorus and silicon but also gas dilution effect. Moreover, bio-based polyol (castor oil) was added to the formulation to increase water contact angle and water resistance. High flame retardancy and enhanced mechanical properties make this formulation highly relevant for industrial applications.