Single-Cylinder Testing of a High-Pressure Electronic Pilot Fuel Injector for Low NOx Emission Dual Fuel Engines: Part II—Optimization, Startability, and Inflammability Testing

1990 ◽  
Vol 112 (3) ◽  
pp. 422-430 ◽  
Author(s):  
J. Workman ◽  
G. M. Beshouri
Keyword(s):  
Fuel Consumption ◽  
Fuel Injection ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Single Cylinder ◽  
Percent Improvement ◽  
Wide Range ◽  
Pilot Fuel ◽  
Dual Fuel Engines ◽  
Low Nox Emission

Single-cylinder testing of an Electronic Pilot Fuel Injection (EPFI) system (reported in Part I) indicated that a 45 percent reduction in NOx emissions could be obtained with a 3 percent improvement in fuel consumption by replacing the mechanical system, delivering 6 percent pilot, with the EPFI at 2.9 percent delivery. Further optimization testing of this system at pilot levels down to 0.7 percent over a wide range of timings and air/fuel ratios resulted in even further reductions in NOx emissions without fuel penalty. The EPFI system can yield NOx emissions levels significantly below 2 g/BHP-h with an improvment in fuel consumption of at least 3–4 percent, and probably yield emissions level as low as 0.5 g/BHP-h without substantial penalties in efficiency or operability.

Single Cylinder Testing of a High-Pressure Electronic Pilot Fuel Injector for Low NOx Emission Dual Fuel Engines: Part I—Baseline, Feasibility, and Comparative Testing

1990 ◽  
Vol 112 (3) ◽  
pp. 413-421 ◽  
Author(s):  
J. Workman ◽  
G. M. Beshouri
Keyword(s):  
Fuel Injection ◽  
Waste Water Treatment ◽  
Injection System ◽  
Dual Fuel ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Pilot Fuel ◽  
Dual Fuel Engines ◽  
Current Minimum ◽  
Feasibility Test

Current dual fuel engines utilizing standard mechanical (Bosch type) fuel injection systems set to 5–6 percent pilot delivery do not appear capable of reducing NOx emissions much below the current minimum of 4 g/bhp-h without incurring substantial penalties in efficiency and operability. A prototype Electronic Pilot Fuel Injector (EPFI) was designed that overcomes the shortcomings of the mechanical injection system, consistently delivering 3 percent or less pilot at pressures as high as 20,000 psi. The EPFI was installed and tested in one cylinder of a standard production dual fuel engine operating at a waste water treatment facility. A feasibility test confirmed that the engine would indeed operate satisfactorily at 2.9 percent pilot. Comparisons with baseline data revealed the EPFI yielded a 45 percent reduction in NOx emissions with a 3 percent or greater improvement in efficiency. Further optimization of the system, discussed in Part II, indicates that even greater reductions in NOx emissions can be obtained without incurring a penalty in fuel consumption.

Influence of Fuel Injection Location in a Small Radial Swirler Low NOx Combustor for Micro Gas Turbine Applications

2019 ◽  
Author(s):  
Gordon E. Andrews ◽  
Su Kim
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Fuel Injection ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Micro Gas Turbine ◽  
Optimum Position ◽  
Pilot Fuel ◽  
Wall Injection ◽  
Injection Location

Abstract The influence of fuel injection location in a low NOx (1) micro-gas turbine [MGT] in the ∼50kWe (kW electric) size range was investigated, for NG and propane, to extend the power turn down using a pilot fuel injector. The low NOx main combustor (1) was a radial swirler with vane passage fuel injection and had ultra-low NOx emissions of 3ppm at 15% O2 at 1800K with natural gas, NG at a combustion intensity of 11.2 MW/m2bara (MW thermal). This was a 40mm diameter outlet eight bladed radial swirler in a 76mm diameter combustor, investigated at 740K air temperature at atmospheric pressure. However, power turn down was poor and the present work was undertaken to determine the optimum position of pilot fuel injection that would enable leaner mixtures to be burned at low powers. Central injection of pilot fuel was investigated using 8 radial outward holes. This was compared with pilot fuel injected at the 76mm wall just downstream of the 40mm swirler outlet. It was show that the central injection pilot was poor with a worse weak extinction than for radial passage fuel injection. The 76mm outlet wall injection was much more successful as a pilot fuel location and had a weak extinction of 0.18Ø compared with 0.34Ø for vane passage fuel injection. NOx emissions were higher for wall fuel injection, but were still relatively low at 16ppm at 15% oxygen for natural gas. This indicates that wall fuel injection could be combined with vane passage fuel injection to improve the micro-gas turbine low NOx performance across the power range.

Effects of Fuel Injection Timing in the Combustion of Biofuels in a Diesel Engine at Partial Loads

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
A. J. Sequera ◽  
R. N. Parthasarathy ◽  
S. R. Gollahalli
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Fuel Injection ◽  
Pollutant Emissions ◽  
Injection Timing ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Single Cylinder ◽  
Fuel Injection Timing ◽  
Partial Loads

Methyl and ethyl esters of vegetable oils have become an important source of renewable energy with convenient applications in compression-ignition (CI) engines. While the use of biofuels results in a reduction of CO, particulate matter, and unburned hydrocarbons in the emissions, the main disadvantage is the increase of nitrogen oxides (NOx) emissions. The increase in NOx emissions is attributed to differences in chemical composition and physical properties of the biofuel, which in turn affect engine operational parameters such as injection delay and ignition characteristics. The effects of fuel injection timing, which can compensate for these changes, on the performance and emissions in a single cylinder air-cooled diesel engine at partial loads using canola methyl ester and its blends with diesel are presented in this study. The engine is a single cylinder, four stroke, naturally aspirated, CI engine with a displacement volume of 280 cm3 rated at 5 HP at 3600 rpm under a dynamometer load. It was equipped with a pressure sensor in the combustion chamber, a needle lift sensor in the fuel injector, and a crank angle sensor attached to the crankshaft. Additionally, the temperature of the exhaust gases was monitored using a thermocouple inside the exhaust pipe. Pollutant emissions were measured using an automotive exhaust gas analyzer. Advanced, manufacturer-specified standard, and delayed injection settings were applied by placing shims of different thicknesses under the injection pump, thus, altering the time at which the high-pressure fuel reached the combustion chamber. The start of injection was found to be insensitive to the use of biofuels in the engine. The late injection timing of the engine provided advantages in the CO and NO emissions with a small penalty in fuel consumption and thermal efficiency.

scholarly journals Investigation on Blending Effects of Gasoline Fuel with N-Butanol, DMF, and Ethanol on the Fuel Consumption and Harmful Emissions in a GDI Vehicle

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1845 ◽  
Author(s):  
Haifeng Liu ◽  
Xichang Wang ◽  
Diping Zhang ◽  
Fang Dong ◽  
Xinlu Liu ◽  
...  
Keyword(s):  
Steady State ◽  
Fuel Consumption ◽  
Large Fraction ◽  
Direct Injection ◽  
Transient State ◽  
Gasoline Direct Injection ◽  
Nox Emissions ◽  
Fuel Blends ◽  
Wide Range ◽  
Oxygenated Fuel

The effects of three kinds of oxygenated fuel blends—i.e., ethanol-gasoline, n-butanol-gasoline, and 2,5-dimethylfuran (DMF)-gasoline-on fuel consumption, emissions, and acceleration performance were investigated in a passenger car with a chassis dynamometer. The engine mounted in the vehicle was a four-cylinder, four-stroke, turbocharging gasoline direct injection (GDI) engine with a displacement of 1.395 L. The test fuels include ethanol-gasoline, n-butanol-gasoline, and DMF-gasoline with four blending ratios of 20%, 50%, 75%, and 100%, and pure gasoline was also tested for comparison. The original contribution of this article is to systemically study the steady-state, transient-state, cold-start, and acceleration performance of the tested fuels under a wide range of blending ratios, especially at high blending ratios. It provides new insight and knowledge of the emission alleviation technique in terms of tailoring the biofuels in GDI turbocharged engines. The results of our works showed that operation with ethanol–gasoline, n-butanol–gasoline, and DMF–gasoline at high blending ratios could be realized in the GDI vehicle without any modification to its engine and the control system at the steady state. At steady-state operation, as compared with pure gasoline, the results indicated that blending n-butanol could reduce CO2, CO, total hydrocarbon (THC), and NOX emissions, which were also decreased by employing a higher blending ratio of n-butanol. However, a high fraction of n-butanol increased the volumetric fuel consumption, and so did the DMF–gasoline and ethanol–gasoline blends. A large fraction of DMF reduced THC emissions, but increased CO2 and NOX emissions. Blending n-butanol can improve the equivalent fuel consumption. Moreover, the particle number (PN) emissions were significantly decreased when using the high blending ratios of the three kinds of oxygenated fuels. According to the results of the New European Drive Cycle (NEDC) cycle, blending 20% of n-butanol with gasoline decreased CO2 emissions by 5.7% compared with pure gasoline and simultaneously reduced CO, THC, NOX emissions, while blending ethanol only reduced NOX emissions. PN and particulate matter (PM) emissions decreased significantly in all stages of the NEDC cycle with the oxygenated fuel blends; the highest reduction ratio in PN was 72.87% upon blending 20% ethanol at the NEDC cycle. The high proportion of n-butanol and DMF improved the acceleration performance of the vehicle.

Effects of Swirler Configurations on Flow Structures and Combustion Characteristics

2004 ◽  
Author(s):  
Guoqiang Li ◽  
Ephraim J. Gutmark
Keyword(s):  
Fuel Injection ◽  
Vortex Breakdown ◽  
Swirling Flow ◽  
Combustion Characteristics ◽  
Pollutant Emissions ◽  
Flow Structures ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
Atmospheric Conditions ◽  
Fuel Injector

Modern gas turbine combustion technologies are driven by stringent regulations on pollutant emissions such as CO and NOx. A combustion system of multiple swirlers coupled with distributed fuel injection was studied as a new concept for reducing NOx emissions by application of Lean Direct Injection (LDI) combustion. The present paper investigates the effects of swirler configurations on the flow structures in isothermal flow and combustion cases using a multiple-swirlers fuel injector at atmospheric conditions. The swirling flow field within the combustor was characterized by a central recirculation zone formed after vortex breakdown. The differences between the tangential and axial velocity profiles, the shape of the recirculation zones and the turbulence intensity distribution for the different fuel injector configurations impacted the flame structure, the temperature distribution and the emission characteristics both for gaseous and liquid fuels. Co-swirling configuration was shown to have the lowest NOx emission level compared with the counter-swirling ones for both types of fuels with lower inlet temperature. In contrast to this, the swirl configuration had less effect on the combustion characteristics in the case of gaseous fuel with high air inlet temperature. The differences in NOx emissions were shown to be closely related to the Damkohler number or the degree to which the flame resembled well-mixed combustion, which is the foundation for LDI combustion.

High Turndown Ratio Low NOx Gas Turbine Combustion

2001 ◽  
Author(s):  
G. E. Andrews ◽  
M. C. Mkpadi
Keyword(s):  
Equivalence Ratio ◽  
Recirculation Zone ◽  
Fuel Injection ◽  
Single Point ◽  
Inlet Temperature ◽  
Fuel Injector ◽  
Main Burner ◽  
Pilot Fuel ◽  
Stage System ◽  
Gas Fuel

The aim of this work was to show that a two-stage system of pilot and main burner could be used to extend the range of minimum to maximum power (turndown) under low NOx conditions. All the combustion air was admitted to the first stage where the natural gas fuel was split between the pilot and the main swirler. The main swirler was a counter-rotating radial swirler, with only the upstream passage fuelled, using a single point fuel injector on the centre of each radial vane passage inlet. Two pilot fuel injector locations were investigated: central radial outward injection and injection into the dump expansion recirculation zone. It was shown at 600K inlet temperature and atmospheric pressure, that with the central pilot fuelled at a constant 0.18 equivalence ratio the main fuel could be increased to 0.7 equivalence ratio with the NOx increasing from 4 to 6 ppm at 15% oxygen. The use of the outer dump expansion recirculation zone for the pilot resulted in excellent turndown, but higher NOx emissions than for the central pilot fuel injection. This gave a very compact low NOx combustor with a high turndown and no acoustic problems.

Unsteady Simulations of a Low NOx LDI Combustor for Environmentally Responsible Aviation Engines

2015 ◽  
Author(s):  
Scott A. Drennan ◽  
Gaurav Kumar ◽  
Erlendur Steinthorsson ◽  
Adel Mansour
Keyword(s):  
Experimental Data ◽  
Complex Geometry ◽  
Mesh Refinement ◽  
Operating Conditions ◽  
Design Parameters ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Cfd Simulations ◽  
Wide Range ◽  
Environmentally Responsible

A key objective of NASA’s Environmentally Responsible Aviation (ERA) research program is to develop advanced technologies that enable 75% reduction of LTO NOx emissions of N+2 aviation gas turbine engines relative to the CAEP 6 standard. To meet this objective, a new advanced multi-point fuel injector was proposed and tested under the NASA ERA program. The new injector, called the three-zone injector, or 3ZI, uses fifteen spray cups arranged in three zones. Swirling air flows into each cup and fuel is introduced via pressure swirl atomizers within the cup. Multiple design parameters impact the performance of the injector, such as the location of the atomizer within the spray cup, the spray angle and cup-to-cup spacing. To fully understand the benefits and trade-offs of various injector design parameters and to optimize the performance of the injector, detailed CFD simulations are an essential tool. Furthermore, the CFD methodology must allow easy changes in design parameters and guarantee consistent and comparable accuracy from one design iteration to the next. This paper investigates the use of LES in reacting and non-reacting flows and compares against the NOx experimental data for the multi-point atomization strategy of the injector. The CFD simulations employ an automatically generated Cartesian cut-cell meshing approach with mesh refinement applied near complex geometry and spray regions. Adaptive Mesh Refinement (AMR) is used to refine mesh in regions of high gradients in velocity and temperature. The CFD simulations use boundary and operating conditions based on experimental data for air flow and spray atomization obtained from LDV and PDPA characterizations of the spray respectively. The results are extended to reacting flow using a detailed reaction mechanism and predictions of NOx emissions are compared to experimental data. Overall NOx predictions were consistently less than experimental values. However, the NOx prediction trends showed excellent agreement with experimental data across the wide range of equivalence ratios investigated.

The NOx and N2O Emission Characteristics of an HCCI Engine Operated With N-Heptane

2007 ◽  
Author(s):  
Hailin Li ◽  
W. Stuart Neill ◽  
Hongsheng Guo ◽  
Wally Chippior
Keyword(s):  
N2o Emission ◽  
Combustion Efficiency ◽  
N2o Emissions ◽  
Emission Characteristics ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Incomplete Combustion ◽  
Hcci Combustion ◽  
Wide Range ◽  
Combustion Phase

This paper presents the NOx and N2O emission characteristics of a Cooperative Fuel Research (CFR) engine modified to operate in Homogeneous Charge Compression Ignition (HCCI) combustion mode using an air-assist port fuel injector. The single-cylinder engine was fuelled with n-heptane for these experiments. The parameters examined include intake air temperature and pressure, air/fuel ratio, compression ratio, and exhaust gas recirculation (EGR) rate. The parameters were varied in order to change the combustion phasing from advanced (knocking) to retarded (incomplete combustion) conditions. NOx emissions were less than 5 ppm for a fairly wide range of combustion phases, except when knocking or incomplete combustion occurred, and were largely unaffected by the parameter varied when the combustion phase was within the acceptable range. It was also found that NOx emissions increased significantly when retarded and incomplete combustion was observed even though lower combustion temperatures were expected. The increased N2O and unburned hydrocarbon (THC) emissions usually observed with retarded combustion phasing, as well as the deteriorated combustion efficiency, may contribute to this unexpected increase in NOx emissions. It was also shown that N2O emissions were extremely low (less than 0.5 ppm) except when incomplete combustion was observed.

Damping of Combustion Instabilities Through Pseudo-Active Control

2018 ◽  
Author(s):  
Jesús Oliva ◽  
Ennio Luciano ◽  
Javier Ballester
Keyword(s):  
Combustion Chamber ◽  
Active Control ◽  
Gas Turbines ◽  
Fuel Injection ◽  
Pressure Oscillation ◽  
Practical Reasons ◽  
Fuel Injector ◽  
Secondary Fuel ◽  
Pilot Fuel ◽  
Instability Control

Active instability control techniques have demonstrated very good capabilities to correct combustion oscillations but, due to high costs and other practical reasons, have not achieved the success expected in gas turbines engines. A different approach, named here as ‘pseudo-active instability control’, has been explored and the first results are presented in this work. In this case, the flow of non-premixed pilot fuel is modulated by passive methods: the pressure oscillation in the combustion chamber induces a velocity fluctuation at the secondary fuel injector. In principle, damping of the instability may be achieved if the heat release oscillations due to the secondary fuel are out of phase with those of the main flame. This work reports a first exploration of this strategy, aimed mainly at performing a proof of the concept. An experimental study has been carried out in a laboratory premixed combustor with pilot fuel injection. The relationship between the fluctuations of pressure in the combustion chamber and those of velocity at the injector was studied both experimentally (hot wire anemometry) and theoretically (1-D acoustic model of the injection line). Combustion tests in limit cycle conditions demonstrated that modifications in the geometry of the secondary injection affected the pressure fluctuations inside the combustion chamber. Depending on the geometry (and, hence, acoustic impedance), the instability was enhanced or damped. This demonstrates that the proposed ‘pseudo-active control’ can produce similar effects (at least, qualitatively) to those of active control, but only using passive means, as initially postulated.

Experimental and Simulation Study of Fuel Injection Timing, Pressure and EGR for Lower Exhaust Emissions From Diesel HCCI Combustion

2009 ◽  
Author(s):  
S. Juttu ◽  
S. S. Thipse ◽  
N. V. Marathe ◽  
M. K. Gajendra Babu
Keyword(s):  
Simulation Study ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Exhaust Emissions ◽  
Injection Timing ◽  
Nox Emissions ◽  
Hcci Combustion ◽  
Fuel Injection Timing ◽  
Start Of Injection ◽  
Wide Range

The objective of this work is to study the effect of different control parameters viz. EGR, fuel injection pressure and start of injection timing on exhaust emissions from diesel fueled HCCI combustion concept. A 4-cylinder LCV engine has been selected for experiments and FIRE 3D CFD software was used for simulation study. The basic idea of the simulation study is to find the suitable EGR ratio to run the engine on HCCI combustion mode so as to avoid any damage to the engine during testing. From simulation study, it was observed that the minimum EGR required for running the engine at 5.6 bar BMEP @ 2500 rpm in HCCI mode is approximately 45%. The trends of simulation results viz. soot and NOx emissions are closely following the experiments. The experiments were conducted at different loads at 2500 rpm and EGR varied from 0% to 60%. With increased EGR ratio, soot bump was observed at 50%, 75% and 100%. The BTE dropped to 24.5% from 33.5%. The effect of fuel injection pressures (750bar, 1000bar and 1500bar) were studied to improve the BTE and to control soot bump over a wide range injection timings EGR ratio. Detailed experiments were conducted at 2.8 bar BMEP @ 2500 rpm to study simultaneous reduction of NOx, SOOT, UHC and CO emissions from diesel HCCI combustion. At injection pressure (1500 bar), advanced fuel injection timing and high EGR ratio, the soot CO and THC emissions were reduced significantly without penalty on NOx emissions. The BTE was improved from 24.5% to 31% against 33.5% of convention diesel combustion.

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