Effects Of Intake Air Temperature Research Articles

Effects of intake air temperature on energy, exergy and sustainability analyses in an RCCI engine fueled with iso-propanol and n-heptane

In this study, performance and emission tests were carried out in a diesel engine operating with RCCI combustion mode by varying the amount of fuel taken into the cylinder and the air temperature in one cycle. Thermodynamic performance was determined by making energy, exergy and sustainability analyzes using the data obtained in the tests. The effects of change in intake air temperature on thermal efficiency, exergy efficiency, exhaust exergy, exergy destruction, and sustainability index were calculated. As the temperature of the air taken into the cylinder increases, the lost exergy decreases and the exergy efficiency increases. At 2500 rpm engine speed, when the amount of fuel taken into the cylinder is 20 mg/cycle, if the inlet temperature is 30°C, 50°C and 70°C, the exergy destruction is 9.873 kW, 9.760 kW and 9.394 kW, respectively. The highest thermal and exergy efficiencies were calculated as 31.58 % and 28.7 %, respectively, at an engine speed of 2000 rpm, when the fuel taken into the cylinder per cycle was 20 mg and the intake air temperature was 70°C. Moreover, the sustainability index was found to be 1.4 under the same conditions. The thermodynamic results show that RCCI mode can be used as alternative combustion mode.

Investigate The Effects of Intake Air Temperature on The Performance and Emissions of The IC Engine Fuelled by Biodiesel B30

The study included the use of biofuel to reduce the percentage of environmental pollution caused by other environmentally polluting fuels that used in other studies. The current study presents investigations of CI engine performance and emissions at various engine speeds under constant engine load. The fuel under consideration in this work is biodiesel B30. A 2.4-liter, 16-valve, 4-cylinder engine with a compression ratio of 15.5:1 is used. Various inlet air temperatures (10 to 35°C with an increment of 5 degrees) are chosen to study their effects on engine performance and emissions. The results show that increasing the inlet air temperature increases brake explicit fuel feasting (BEFF) beside to nitrogen oxide (NOx), while decreasing the brake power and torque. In this scientific revision, a tentative analysis was conducted on a CI engine at various engine speeds and inlet air temperatures., The results were obtained at engine speeds of 2100 rpm at various engine loads and revealed an increase in BSFC of biodiesel blends (B20, B50, and B100) as injection pressure was increased.

Influence of intake air temperature on the performance of gasoline engines using a different type of fuel

The aim of the present study is to investigate the effect of Intake air temperature on the performance of gasoline engines. Various factors are taken that affect the performance of four-stroke gasoline engines. Changes in air intake temperature have a significant impact on the performance of a petrol engine. Consequently, an increase or decrease in the global ambient temperature will impact the performance and air quality of gasoline engines in particular. therefore, this investigation will discover the hot value of intake air temperatures that effects engine performance. This study tested two Kurdistan-Iraq gasoline kinds at different intake temperatures (25Co, 35Co, 45Co, and 50Co). Experiments utilized a four-stroke spark ignition _engine that operated at various rates of speeds (1300, 1500, 1800, 2000, 2300 and 2500 revolutions per minute) under a half load with a 50% throttle opening. The experimental outcomes were compared with Ricardo Wave software simulations. The Ricardo Wave's theoretical outcomes were in good agreement with the experiment data it showed a near 5% to 10% variance between simulation and practical data. Additionally, utilizing fuels having higher RON increases brake power owing to gasoline's greater hydrogen content and the engine's high octane fuel requirement. Also, lower inlet air temperatures would be denser (more oxygen) and offer a larger mass flow during each piston cycle. Hence, due to those factors, brake power was enhanced by reducing intake temp and raising RON. Generally, the experiment results demonstrated that utilizing higher octane number gasoline under lower intake temperature improved engine performance which demonstrates higher power, torque, and efficiency with lower bsfc compared to utilizing higher intake temperature and lower octane gasoline.

Effect of Intake Air Temperature and Premixed Ratio on Combustion and Exhaust Emissions in a Partial HCCI-DI Diesel Engine

Homogeneous charge compression ignition (HCCI) is considered an advanced combustion method for internal combustion engines that offers simultaneous reductions in oxides of nitrogen (NOx) emissions and increased fuel efficiency. The present study examines the influence of intake air temperature (IAT) and premixed diesel fuel on fuel self-ignition characteristics in a light-duty compression ignition engine. Partial HCCI was achieved by port injection of the diesel fuel through air-assisted injection while sustaining direct diesel fuel injection into the cylinder for initiating combustion. The self-ignition of diesel fuel under such a set-up was studied with variations in premixed ratios (0–0.60) and inlet temperatures (40–100 °C) under a constant 1600 rpm engine speed with 20 Nm load. Variations in performance, emissions and combustion characteristics with premixed fuel and inlet air heating were analysed in comparison with those recorded without. Heat release rate profiles determined from recorded in-cylinder pressure depicted evident multiple-stage ignitions (up to three-stage ignition in several cases) in this study. Compared with the premixed ratio, the inlet air temperature had a greater effect on low-temperature reaction and HCCI combustion timing. Nonetheless, an increase in the premixed ratio was found to be influential in reducing nitric oxides emissions.

Biodiesel fueled combustion performance and emission characteristics under various intake air temperature and injection timing conditions

Abstract The purpose of this investigation is to clarify the combustion performance and exhaust emissions characteristics of biodiesel fueled compression ignition diesel engine under various intake air temperature and injection timing conditions. In order to clearly figure out the effect of intake air temperature, the flow rate of intake air was controlled at constant value before heating air. In addition, the engine speed and fuel injection quantity were fixed. Hence, the charging efficiency is constant even if the intake air temperature changes. At the injection timing BTDC 6° and 9°, high IMEPnet occurred and less NOX and HC were emitted. Here, as the intake air temperature increased, the vaporization characteristics of the fuel were improved and the ignition timing advanced close to TDC. Also, it was confirmed that the combustion duration prolonged. As a result, when the intake air temperature increases from 20 °C to 100 °C, IMEPnet increased slightly (0.39 → 0.41 MPa) owing to decreasing negative work and THC (0.85 → 0.51 g/kWh) and CO (3.72 → 1.34 g/kWh) emissions decreased, but NOX emission increased slightly (3.69 → 4.82 g/kWh). In addition, although the diameter of the most emitted PM increased relatively, the number decreased.

Effects of high intake-air temperature on emission characteristics under constant charging efficiency

The purpose of study is to analyze effect of intake air temperature in accordance with injection timings on combustion and emission characteristics. The operating conditions were fixed engine speed was 1800 rpm, and injection quantity was 17 mg. The injection timing was advanced from BTDC 6° to BTDC 24° at intervals of 3°. When the intake air flow rate was fixed before controlling intake air temperatures, the charging efficiency did not change with intake air temperature. Hence, the effect of only the intake air temperature was analyzed. When the intake air temperature was 100 °C compared to 20 °C, the IMEPnet increased by about 14.5% (0.55 MPa → 0.63 MPa) at the optimum injection timing (BTDC 6°, 9°). Because this high temperature reduced the ignition delay and advanced the ignition timing close to the TDC resulting in reducing negative work. In addition, the difference in NOx emission for different intake air temperatures was insignificant. When the intake air temperature was 100 °C compared to 20 °C, the high intake air temperature reduced the emissions of THC by about 41.3% (0.196 g/kWh → 0.115 g/kWh) and nanoparticles by about 60.5% (1188 μg/m3 → 468.6 μg/m3) by improving the evaporability of the fuel. In addition, carbon monoxide (CO) emissions decreased by about 45.3% (3.86 g/kWh → 2.11 g/kWh) in the case of 80 °C compared to 20 °C. Thus, the increase in the intake air temperature under constant intake air mass flow rate improved the combustion efficiency and reduced emission of THC, CO, and nanoparticles without increasing NOX emissions.

Exergy loss analysis on diesel methanol dual fuel engine under different operating parameters

In order to reveal the mechanism of high thermal efficiency of diesel methanol dual fuel (DMDF) engine, the exergy loss of DMDF engine under different operating parameters is investigated by using experimental and calculative methods based on the second law of thermodynamics. It has been found that DMDF has lower heat transfer exergy loss under all engine loads due to the high latent heat of vaporization of methanol which reduces the temperature in-cylinder. The exhaust exergy loss of DMDF under high load is relatively low compared with that of pure diesel fuel, while it is opposite to that under medium-low load. This is due to the influence of different temperatures on the incomplete combustion of methanol, which also indicates the main cause for the high thermal efficiency of DMDF under high load. Then studies on exergy analysis of DMDF under different temperatures were carried out. The studies covers the effect of intake air temperature on exergy efficiency, the heat transfer exergy loss and the exhaust physical exergy loss increase with rising intake air temperature as well. The results shows that the exhaust chemical exergy loss decreases significantly with the increase of intake air temperature and higher intake air temperature helps to improve exergy efficiency. Additionally, it is concluded that higher methanol temperature and cooling water temperature can improve exergy efficiency by decreasing exhaust exergy loss and combustion irreversible exergy loss. Finally, some feasible measures are proposed to further improve DMDF engine’s performance.

The Effect of Intake Air Temperature on Spark Ignition Engine Performance

The Effect of Intake Air Temperature on Spark Ignition Engine Performance

Compression Ratio and Intake Air Temperature Effect on the Fuel Flexibility of Compression Ignition Engine

<div class="section abstract"><div class="htmlview paragraph">The effect of compression ratio (CR) and intake air temperature on the combustion characteristics of fuels with different octane ratings were investigated on a single-cylinder heavy duty engine. The study focused on Primary Reference Fuels (PRFs) and commercial grade diesel with octane numbers ranging from 0 to 100. The engine was configured at a CR of 11.5:1, which is lower than typical heavy-duty compression ignition CI engines. This aims to compare the fuels’ burning regime with recently reported measurements at CR17:1. Experiments were performed at different intake air temperatures of 20 to 80 °C and net indicated mean effective pressure (IMEP<sub>Net</sub>) of 5 to 20 bar. The injection rates have been characterized to determine the hydraulic delay of the injector and thus define the actual ignition delay time. At low loads, diesel-like fuels were found to burn in partially premixed combustion (PPC) mode whereas high octane fuels did not ignite. At high loads, fuels combustion becomes diffusion driven regardless of their RON or MON values. The effect of intake air temperature on the combustion characteristics depended on the combination of the octane ratings and the engine load. At high loads, fuels with low octane numbers were insensitive to the change of the intake air temperature. The ignition delay time was short enough to maintain a diffusion driven combustion. At lower loads, it is more challenging to reach conditions where the combustion characteristics are invariant regardless of the fuel’s RON and MON values (Fuel Flexible). At the low tested compression ratio of 11.5:1, the extent of fuel flexibility is limited to only high loads (IMEP<sub>Net</sub> = 20 bar) whereas it is extended to intermediate loads (IMEP<sub>Net</sub> = 10 and 15 bar) at CR17:1.</div></div>

Experimental investigation on the effect of charge temperature on ethanol fueled HCCI combustion engine

In this investigation, an attempt has been made to study by varying the charge temperature on the ethanol fueled Homogeneous charge compression ignition (HCCI) combustion engine. Ethanol was injected into the intake manifold by using port fuel injection technique while the intake air was heated for achieving stable HCCI operation. The effect of intake air temperature on the combustion, performance, and emissions of the ethanol HCCI operation was compared with the standard diesel operation and presented. The results indicate that the intake air temperature has a significant impact on in-cylinder pressure, ringing intensity, combustion efficiency, thermal efficiency and emissions. At 170°C, the maximum value of combustion efficiency and brake thermal efficiency of ethanol are found to be 98.2% and 43%, respectively. The NO emission is found to be below 11 ppm while the smoke emission is negligible. However, the UHC and CO emissions are higher for the HCCI operation.

Effect of intake air temperature and common-rail pressure on ethanol combustion in a single-cylinder light-duty diesel engine

Gasoline compression ignition (GCI) engines have a great potential to achieve the simultaneous reduction of smoke and nitrogen oxides (NOx) emissions via partially premixed combustion (PPC) using low cetane number fuel for the extended pre-combustion mixing time. The premixed combustion realised in high compression ratio engines also improves the engine efficiency with previous studies often reporting 50% brake efficiency or higher. The ability to control the combustion phasing by the fuel injection timing differentiates this new regime from widely investigated homogenous charge compression ignition (HCCI) or its variants making it a practical alternative to conventional gasoline or diesel combustion. In this study, ethanol produced from biomass has been selected as a GCI fuel, considering its higher octane number (i.e. lower cetane number), evaporative cooling and oxygen contents than gasoline, all of which could further improve the GCI combustion. The ethanol-fuelled GCI, or in short ECI, was investigated in a single-cylinder automotive-size diesel engine connected to an Eddy Current (EC) dynamometer. The focus is the engine start-up conditions and the influence of intake air temperature and common-rail pressure on ECI combustion. From the experiments, it is found that the engine can be successfully started by ECI combustion using a conventional start motor at low engine speed of 1000rpm when the intake air temperature is higher than 60°C. For higher engine speed of 2000rpm and stable operations, however, a double injection strategy and increased intake air temperature of 80°C are required suggesting the important role of wall wetting on ECI combustion. From the intake air temperature variations up to 100°C, it is observed that both the peak in-cylinder pressure and heat release rate increase, leading to the improved engine efficiency. The measured engine-out emissions of unburnt hydrocarbon and carbon monoxide also show a decreasing trend with increasing intake air temperature, likely due to the reduced wall wetting. The smoke and NOx emissions of ECI combustion are much lower than those of a conventional diesel, regardless of the intake air temperature. The common-rail pressure variations at fixed brake power conditions show that the friction loss increases with increasing common-rail pressure, leading to the increased brake specific fuel consumption. This suggests that the common-rail pressure for ECI applications should remain low for the efficiency gain. The engine-out emissions also exhibit an increasing trend with increasing common-rail pressure although the smoke and NOx levels are always lower than that of a conventional diesel. Compared to the diesel reference case, the optimised engine operating conditions of this study achieves 50% higher fuel conversion efficiency, 5% lower brake specific fuel consumption and 27% lower NOx emissions while smoke emissions are kept at a negligible level.

The impact of intake air temperature on performance and exhaust emissions of a diesel methanol dual fuel engine

To better understand how the intake air temperature and methanol fumigation affect the performance and emissions of diesel engine, a parametric study concerned with methanol mass fraction and intake air temperature was conducted. In this study, methanol port injection was used for preparing homogenous charge for diesel methanol dual fuel operation on a 6-cylinder turbocharged intercooler heavy duty (HD) diesel engine. The testing work was operated at a constant load and constant engine speed of 1500r/min. The experimental results show that there was a strong coupling between the intake air temperature and the methanol fraction to performance and emissions of the engine. At dual fuel operation mode, decreasing intake air temperature reduced the indicated thermal efficiency and exhaust gas temperature and the trend was more evidently as methanol energy fraction increased. Decreasing of intake air temperature also prolonged the ignition delay, which caused a later combustion phasing and smaller peak cylinder pressure. By the induction of methanol, NOX, NO and smoke emissions decreased markedly, while NO2, CO, total hydrocarbon (THC), formaldehyde and methanol emissions increased. However, increasing the intake air temperature would inhibit the NO2, THC, CO, formaldehyde and methanol emissions and increase NO, NOX and soot emissions. The effect of intake air temperature and methanol fraction on emissions is more remarkably at a larger methanol fraction (30% or more) and higher intake air temperatures such as 60–70°C.

Effects of intake air temperature on homogenous charge compression ignition combustion and emissions with gasoline and n-heptane

In a port fuel injection engine, Optimized kinetic process (OKP) technology is implemented to realize HCCI combustion with dual-fuel injection. The effects of intake air temperature on HCCI combustion and emissions are investigated. The results show that dual-fuel control prolongs HCCI combustion duration and improves combustion stability. Dual-fuel HCCI combustion needs lower intake air temperature than gasoline HCCI combustion, which reduces the requirements on heat management system. As intake air temperature decreases, air charge increases and maximum pressure rising rate decreases. When intake air temperature is about 55?C, HCCI combustion becomes worse and misfire happens. In fixed dual fuel content condition, HC and CO emission decreases as intake air temperature increases. The combination of dual-fuel injection and intake air temperature control can expand operation range of HCCI combustion.

Effects of intake air temperature on combustion, performance and emission characteristics of a HCCI engine fueled with the blends of 20% n-heptane and 80% isooctane fuels

In this study, the effects of intake air temperature on the cylinder pressure, heat release rate, start of combustion, combustion duration, engine performance and exhaust emissions were investigated in a HCCI gasoline engine fueled with the blends of 20% n-heptane and 80% isooctane fuels. Intake air temperature was changed from 40°C to 120°C. The experiments were performed with a single-cylinder, four-stroke HCCI gasoline engine at two different excessive air coefficients at 1200rpm. The results showed that in-cylinder pressure and heat release rate increased with the increase of intake air temperature. The increase of intake air temperature caused combustion to advance and the combustion duration to decrease. At 70°C intake air temperature, brake torque decreased by 3.1% when the engine operated with λ=0.6 compared to λ=0.7. The specific fuel consumption and NO emissions tend to increase at higher intake air temperatures of 100°C and 120°C. It was also found that CO and HC emissions firstly increased and then started to decrease after the 90 °C intake air temperature.

Effect of Intake Air Temperature on the Performance and Emissions Characteristics of SI Engine

Effect of Intake Air Temperature on the Performance and Emissions Characteristics of SI Engine

Combustion and Emission Characterization of n-Butanol Fueled HCCI Engine

Biofuels are attracting global attention as alternate transportation fuels due to advantages of their being produced from locally available renewable resources, lower pollution potential, and biodegradable nature. Butanol is fast emerging as one of the competitive biofuels for use in transportation engines. Homogeneous charge compression ignition (HCCI) engines have shown great potential for higher engine efficiency and ultralow NOx and particulate matter (PM) emissions. This experimental study is therefore carried out to combine the advantages of biofuels and HCCI engines, both. Detailed performance, combustion, and emission characteristics of n-butanol fueled HCCI engine are investigated experimentally. The study is conducted on a four cylinder diesel engine, whose one cylinder was modified to operate in HCCI combustion mode. Port fuel injection technique was used for homogeneous charge preparation in the intake manifold. Auto-ignition of fuel in the engine cylinder was achieved by intake air preheating. In-cylinder pressure-crank angle data acquisition with subsequent heat release analyses and exhaust emission measurements were done for combustion and emission characterization. In this paper, the effect of intake air temperature and air–fuel ratio on the combustion parameters, thermal and combustion efficiency, ringing intensity (RI), and emissions from n-butanol fueled HCCI engine were analyzed and discussed comprehensively. Empirical correlations were derived to fit the experimental data for various combustion parameters.

Experimental investigations of performance, combustion and emission characteristics of ethanol and methanol fueled HCCI engine

Homogeneous charge compression ignition (HCCI) engines have potential to provide both diesel like efficiencies and very low NOx and particulate matter (PM) emissions. There is growing global interest in using alternative biofuels in order to reduce the reliance on conventional fossil fuels. Therefore this experimental study was carried out to investigate performance, combustion and emission characteristics of HCCI engine fueled with ethanol and methanol and compare it with baseline gasoline fuel. The experiments were conducted on a modified four-cylinder four-stroke engine at different engine speeds using port fuel injection technique for preparing homogeneous charge. To achieve auto-ignition of air–fuel mixture in the combustion chamber, intake air pre-heater was used. In-cylinder pressure data acquisition with subsequent heat release analysis and exhaust emission measurements were done for combustion and emission diagnostics. In this paper, effect of intake air temperature and air–fuel ratio on combustion parameters, thermal efficiency, combustion efficiency, ringing intensity and emissions in HCCI engine is analyzed and discussed. Results show that methanol and ethanol are good replacements to gasoline in HCCI combustion mode.

Effect of intake air temperature and air–fuel ratio on particulates in gasoline and n-butanolfueled homogeneous charge compression ignition engine

An experimental study was conducted to investigate the effect of engine operating parameters on exhaust particulate size–number distribution in a homogeneous charge compression ignition engine fueled with gasoline and n-butanol. In this investigation, portfuel injection was done for preparing homogeneous charge, and intake air preheating was used for auto-ignition of the charge. Engine exhaust particle sizer was used for measuring size–number distribution of particulate matter emitted from the homogeneous charge compression ignition engine. Experiments were conducted at different engine speeds by varying intake air temperature and air–fuel ratio of the charge. Effect of engine operating parameters on particulate size–number distribution, size–surface area distribution, and total particulate number concentration was investigated. Most significant particle numbers were in the range of 6–150 nm mobility diameter for all test conditions. n-Butanol showed relatively higher peak number concentration and lower mobility diameter corresponding to the peak concentrations as compared to baseline gasoline. On increasing intake air temperature, mobility diameters corresponding to peak number concentration of particles moved towards lower mobility diameters. Count mean diameter of particles was in the range of 35–80 nm and 20–65 nm for gasoline and n-butanol, respectively, for all test conditions in homogeneous charge compression ignition operating range.

Effects of intake air temperature on SI engine emissions during a cold start

This paper presents the concept of preheating the intake air to reduce cold-start emissions from gasoline engines. The effects of intake air temperature on emissions from a gasoline engine were studied by using an air heater based on spark ignition. A light-duty vehicle test of cold-start emissions was carried out at an ambient temperature of−7°C according to New European Driving Cycle for Euro 3 and Euro 4 exhaust emission legislations. The results showed that preheating the intake air could effectively reduce both hydrocarbon (HC) and carbon monoxide (CO) emissions and improve fuel economy during a cold start. During idling conditions, the key phase of the HC and CO emissions was the first 40 s. With the aid of the air heater, cold-start HC and CO emissions from the vehicle were lower than the limit values in the Euro 3 and Euro 4 regulations.

Experimental investigation on the effect of intake air temperature and air–fuel ratio on cycle-to-cycle variations of HCCI combustion and performance parameters

Combustion in HCCI engines is a controlled auto ignition of well-mixed fuel, air and residual gas. Since onset of HCCI combustion depends on the auto ignition of fuel/air mixture, there is no direct control on the start of combustion process. Therefore, HCCI combustion becomes unstable rather easily, especially at lower and higher engine loads. In this study, cycle-to-cycle variations of a HCCI combustion engine fuelled with ethanol were investigated on a modified two-cylinder engine. Port injection technique is used for preparing homogeneous charge for HCCI combustion. The experiments were conducted at varying intake air temperatures and air–fuel ratios at constant engine speed of 1500 rpm and P- θ diagram of 100 consecutive combustion cycles for each test conditions at steady state operation were recorded. Consequently, cycle-to-cycle variations of the main combustion parameters and performance parameters were analyzed. To evaluate the cycle-to-cycle variations of HCCI combustion parameters, coefficient of variation (COV) of every parameter were calculated for every engine operating condition. The critical optimum parameters that can be used to define HCCI operating ranges are ‘maximum rate of pressure rise’ and ‘COV of indicated mean effective pressure (IMEP)’.