scholarly journals Parametric Study of Injection Rates With Solenoid Injectors in an Injection Quantity and Rate Measuring Device

2014 ◽  
Author(s):  
Stephen Busch ◽  
Paul C. Miles
Keyword(s):  
Single Injection ◽  
Injection Rate ◽  
Physical Parameters ◽  
Fuel Injector ◽  
Mixture Formation ◽  
Measuring Device ◽  
Multiple Injections ◽  
Injection Quantity ◽  
Main Injection ◽  
Injection Rates

The rate at which fuel is injected into the cylinder of a direct injection Diesel engine has significant implications for the ensuing mixture formation and combustion processes. Advances in fuel injector technology enable a variety of advanced injection strategies, particularly very closely coupled injection events. In this work, a Moehwald HDA injection quantity and rate measuring unit is used to investigate the injection rates obtained with a pre-production solenoid injector with a fast acting, pressure-balanced control valve using a blend of n-hexadecane and heptamethylnonane (DPRF58). The effects of digital signal filtering on the rate shape and injected mass are investigated for a single injection. Additionally, the effects of physical parameters such as fuel and measurement chamber temperature, axial clamping force on the injector, high pressure line length, and solenoid current pull up time on the rate shape are investigated. The primary purpose of these simple parameter variations is to establish whether or not they have an impact on the measured injection rate traces and/or total measured injected masses. At each dwell time, the rates of injection are compared between the three injectors tested. These results show that these pre-production injectors can operate with very short dwell times while the injection rate curves indicate distinct pilot and main injection events and an influence of dwell on the rate shape of the main injection. Testing with PRF, a blend of n-heptane and isooctane, shows that while rates of injection are comparable to those obtained with the DPRF for a single injection, they are dramatically different for multiple injections. This has significant implications for the optical diagnostic techniques that may be employed to study the effects of multiple injections on the mixture formation process.

scholarly journals Parametric Study of Injection Rates With Solenoid Injectors in an Injection Quantity and Rate Measuring Device

2015 ◽  
Vol 137 (10) ◽  
Author(s):  
Stephen Busch ◽  
Paul C. Miles
Keyword(s):  
Parametric Study ◽  
Single Injection ◽  
Injection Rate ◽  
Hydraulic Pressure ◽  
Measuring Device ◽  
Injection Quantity ◽  
Main Injection ◽  
Fast Acting ◽  
Measuring Unit ◽  
Injection Rates

A Moehwald HDA (HDA is a German acronym: Hydraulischer Druckanstieg: hydraulic pressure increase) injection quantity and rate measuring unit is used to investigate injection rates obtained with a fast-acting, preproduction diesel solenoid injector. Experimental parametric variations are performed to determine their impact on measured injection rate traces. A pilot–main injection strategy is investigated for various dwell times; these preproduction injectors can operate with very short dwell times with distinct pilot and main injection events. Dwell influences the main injection rate shape. A comparison between a diesel-like fuel and a gasoline-like fuel shows that injection rates are comparable for a single injection but dramatically different for multiple injections with short dwells.

scholarly journals Effects of multiple injections on combustion and emissions in a heavy-duty diesel engine at high load and low speed

2020 ◽  
Vol 12 (12) ◽  
pp. 168781402098462
Author(s):  
Yingying Lu ◽  
Yize Liu
Keyword(s):  
Diesel Engine ◽  
Single Injection ◽  
High Load ◽  
Post Injection ◽  
Heavy Duty ◽  
Low Speed ◽  
Multiple Injections ◽  
Heavy Duty Diesel Engine ◽  
Main Injection ◽  
Heavy Duty Diesel

Advanced multiple injection strategies have been suggested for compression ignition engines in order to meet the increasingly stringent emission regulations. Experiments and simulations were used to study effects of the main-injection mode (times), the post-injection proportion, and timing on combustion and emissions in a heavy-duty diesel engine at high load and constant low speed. The results reveal the following. The NOx emissions of 1main+1post, 2main+1post, and 3main+1post injections are all lower than those of single injection; the higher the number of main-injection pluses, the lower the NOx emissions. Enough main-post injection interval is needed to ensure post and main injections are relatively independent to entrain more fresh air to decrease the soot. Over-retarded post-injection timing tends to increase the soot due to the lower in-cylinder temperature. The combined effects of formation and oxidation determine the final soot. To gain the best trade-off of NOx and soot, compared with single injection, for the three multiple injections, the lowest soot emissions are gained at post-injection proportions of 15% and post-injection timings of 25°, 30°, and 35° CA ATDC, with soot reductions of 26.7%, −34.5%, and −112.8%, and NOx reductions of 5.88%, 21.2%, and 40.3%, respectively, for 1main+1post, 2main+1post, and 3main+1post injections.

Study on the Transient Injection Rate of Each Nozzle Hole in the Combustion Process of Diesel Engine

2020 ◽  
Vol 143 (7) ◽  
Author(s):  
Liying Zhou ◽  
Yu Liang
Keyword(s):  
Diesel Engine ◽  
Exothermic Reaction ◽  
Combustion Process ◽  
Injection Rate ◽  
Dynamics Simulation ◽  
Ratio Distribution ◽  
Fuel Distribution ◽  
Injection Quantity ◽  
Nozzle Hole ◽  
Injection Rates

Abstract Based on the measured injection rates obtained from the spray momentum experiment, the three-dimensional computational fluid dynamics simulation study on the effect of injection rate from each nozzle hole on spray characteristics and combustion process was conducted for a one-cylinder diesel engine. The simulation model was successfully verified by the data of the experiment. The results show that at the beginning and mid-stages of injection, the nozzles with a higher transient injection rate exhibit higher jet velocity, bigger spray penetration distance, and wider equivalence ratio distribution. Besides, the disturbance induced by fuel injection on their surrounding gas is higher. Due to the difference in injection rates from each nozzle hole in the cylinder, gas–fuel mixtures are non-uniform. In the case of measured injection rates from each nozzle hole, Hole 4 records the highest instantaneous injection rate. This results in the injection of more fuel during ignition delay. More heat generated from thermal chain reactions raises fuel spray temperatures and quicker ignition of mixtures. In the case of uniform simulated injection rate (injection quantity values are the same as in the previous case), more uniform flow fields and stronger small swirl motions were generated that enhance fuel atomization and mixture formations. At the later stages of injection and combustion, quicker diesel fuel burning rate with a centralized exothermic reaction process occurs due to in-cylinder uniform fuel distribution and air motion. In the case of simulating uniform injection rate from three holes and non-injection from one (same injection quantity values as previous cases), uneven fuel distribution that occurs in the cylinder will result in poor mixture formations and subsequently poor combustion, and more afterburning will occur.

Effect of split injection on mixture formation and combustion processes of diesel spray injected into two-dimensional piston cavity

2017 ◽  
Vol 232 (8) ◽  
pp. 1121-1136 ◽  
Author(s):  
Kang Yang ◽  
Hirotaka Yamakawa ◽  
Keiya Nishida ◽  
Youichi Ogata ◽  
Yusuke Nishioka
Keyword(s):  
Soot Formation ◽  
Single Injection ◽  
Injection Pressure ◽  
Diesel Spray ◽  
Two Dimensional ◽  
Mixture Formation ◽  
Split Injection ◽  
Main Injection ◽  
Combustion Processes ◽  
Injection Strategies

The objective of this study is to obtain an enhanced understanding of the effect of split injection on mixture formation and combustion processes of diesel spray. A two-dimensional (2D) piston cavity of the same shape as that used in a small-bore diesel engine was employed to form the impinging spray flame. The fuel was injected into a high pressure, high temperature constant volume vessel through a single-hole nozzle with a hole diameter of 0.11 mm. The injection process comprised a pre-injection followed by the main injection. The main injection was carried out either as a single injection of injection pressure 100 MPa (Pre+S100), or by two types of split injection of injection pressure 160 MPa. The latter two types were defined by mass fraction ratios 1:1 and 3:1 (Pre+D160_1-1, Pre+D160_3-1). In order to observe the spray mixture formation process, the tracer laser absorption scattering (LAS) techique was adopted. Tracer LAS fuel with 97.5 vol% of n-tridecane and 2.5 vol% of 1-methylnaphthalene (α-MN) was employed. The spatial distributions of the vapor and liquid phases and the spray mixture formation characteristics in the 2D piston cavity for the three injection strategies were investigated. The diesel spray combustion and soot formation processes were studied using a high-speed video camera. The flame structure and soot formation process were examined using two-color pyrometry. The experimental results revealed that the split-injection vapor distribution was significantly more homogeneous than that of the single injection. The main injection fuel caught up with the pre-injection fuel and provided the spray tip with substantial additional momentum, enabling it to advance further. A high soot concentration and low temperatures appeared near the cavity wall region under the three injection strategies. The soot reduction rate for split injection was higher than that for single injection. The second main injection caught up with the previous injection’s flame, which deteriorated the combustion and resulted in higher soot generation. The effect of split injection on the process of soot evolution finished at the same time as that of single injection.

Investigation of the Optimal Injection Conditions for a PCCI Diesel Engine

2012 ◽  
Author(s):  
Yungjin Kim ◽  
Sangki Park ◽  
Kihyung Lee
Keyword(s):  
Combustion Process ◽  
Injection Rate ◽  
Homogeneous Mixture ◽  
Injection Timing ◽  
Emission Characteristics ◽  
Split Injection ◽  
Multiple Injections ◽  
Indicated Mean Effective Pressure ◽  
Main Injection ◽  
Optimal Injection

Premixed charge compression ignition (PCCI) engines have the potential with their attractive advanced combustion process to achieve a more homogeneous mixture and a lower peak combustion temperature resulting in both lower nitrogen oxides (NOx) and diesel particulate matter (PM) emissions. In this study, the spray characteristics for a PCCI engine according to various injection conditions were introduced and then the effects of injection strategies such as injection angles, injection timings and times on combustion and emissions were studied for a single cylinder PCCI engine using early multiple injections first. Add more, a method of early-main type split injection was used for a 4-cylinder PCCI engine and the effects of injection conditions on the combustion and emission characteristics were investigated. Finally flame visualization tests were performed to validate the result obtained from the engine test. The experimental results showed that the mixture formation, indicated mean effective pressure (IMEP), and emission characteristics were dominantly affected by the injection conditions and the multiple injection method resulted in higher IMEP and still low smoke level characteristics. It appeared that more homogeneous mixture could be formed with decreasing of spray penetration and increasing of fuel evaporation rate for the early multiple injections. In case of the split injection, both injection timing and injected fuel ratio of the early and main injection largely affected engine combustion and emission characteristics. From the results, as the early injection rate increased premixed combustion was activated, on the other hand, as the main injection rate increased conventional diesel combustion was activated, therefore suitable split injection conditions could be selected for the 4-cylinder PCCI engine.

CALCULATION OF OPTIMAL INJECTION RATE FOR DISPERSED WATERFLOODING SYSTEM

2017 ◽  
pp. 63-67
Author(s):  
L. A. Vaganov ◽  
A. Yu. Sencov ◽  
A. A. Ankudinov ◽  
N. S. Polyakova
Keyword(s):  
Injection Rate ◽  
Oil Field ◽  
Injection Well ◽  
Water Migration ◽  
Mutual Location ◽  
Optimal Injection ◽  
Technical Measures ◽  
Injection Rates

The article presents a description of the settlement method of necessary injection rates calculation, which is depended on the injected water migration into the surrounding wells and their mutual location. On the basis of the settlement method the targeted program of geological and technical measures for regulating the work of the injection well stock was created and implemented by the example of the BV7 formation of the Uzhno-Vyintoiskoe oil field.

scholarly journals Capillary processes increase salt precipitation during CO2 injection in saline formations

2018 ◽  
Vol 852 ◽  
pp. 398-421
Author(s):  
Helena L. Kelly ◽  
Simon A. Mathias
Keyword(s):  
High Salinity ◽  
Volume Fraction ◽  
Injection Rate ◽  
Injection Well ◽  
Co2 Injection ◽  
Salt Precipitation ◽  
Injection Wells ◽  
Tenfold Increase ◽  
Entry Pressure ◽  
Injection Rates

An important attraction of saline formations for CO2 storage is that their high salinity renders their associated brine unlikely to be identified as a potential water resource in the future. However, high salinity can lead to dissolved salt precipitating around injection wells, resulting in loss of injectivity and well deterioration. Earlier numerical simulations have revealed that salt precipitation becomes more problematic at lower injection rates. This article presents a new similarity solution, which is used to study the relationship between capillary pressure and salt precipitation around CO2 injection wells in saline formations. Mathematical analysis reveals that the process is strongly controlled by a dimensionless capillary number, which represents the ratio of the CO2 injection rate to the product of the CO2 mobility and air-entry pressure of the porous medium. Low injection rates lead to low capillary numbers, which in turn are found to lead to large volume fractions of precipitated salt around the injection well. For one example studied, reducing the CO2 injection rate by 94 % led to a tenfold increase in the volume fraction of precipitated salt around the injection well.

scholarly journals Optimal injection rate of water in the Guide Basin hot dry rock mining project

2018 ◽  
Vol 37 (2) ◽  
pp. 721-735 ◽  
Author(s):  
Xiaoxue Yan ◽  
Yanguang Liu ◽  
Guiling Wang ◽  
Yaoru Lu
Keyword(s):  
Injection Rate ◽  
Heat Extraction ◽  
Qinghai Province ◽  
Hot Dry Rock ◽  
Rock Mining ◽  
Optimal Injection ◽  
Production Stages ◽  
Reservoir Simulator ◽  
Guide Basin ◽  
Injection Rates

The energy reserves of hot dry rock resources are huge, thus a model to predict engineering production for efficient and stable development and utilization is sought. Based on the geological characteristics of dry rock resources in Guide Basin, Qinghai Province, China, the fully coupled wellbore–reservoir simulator—T2Well—is used to model a production system using water as a heat transfer medium and simulate the system’s operation to analyze the influence of different injection rates on heat extraction. In later production stages, output temperature and reservoir pressure decrease by 10–30°C and 0.5–30 MPa, depending on injection rate; this occurs earlier and to a greater extent at higher injection rates; thermal breakthrough also occurs earlier (7–10 years). The heat extraction rate is 1–20 MW and the cumulative heat extracted is 2.1–24.2 × 105 J. Lower injection rates result in relatively low heat extraction rates. For maximum economic benefit, an injection rate of 50–75 kg/s is ideal.

An Experimental Study on Smoke Reduction Effect of Post Injection in Combination With Pilot Injection for a Diesel Engine

2013 ◽  
Vol 136 (4) ◽  
Author(s):  
Long Liu ◽  
Naoto Horibe ◽  
Tatsuya Komizo ◽  
Issei Tamura ◽  
Takuji Ishiyama
Keyword(s):  
Diesel Engine ◽  
Injection Pressure ◽  
Injection Timing ◽  
Nox Emissions ◽  
Pilot Injection ◽  
Post Injection ◽  
Spray Flames ◽  
Injection Quantity ◽  
Main Injection ◽  
Reduction Effect

With the universal utilization of the common-rail injection system in automotive diesel engines, the multistage injection strategies have become typical approaches to satisfy the increasingly stringent emission regulations, and especially the post injection has received considerable attention as an effective way for reducing the smoke emissions. Normally the post injection is applied in combination with the pilot injection to restrain the NOx emissions, smoke emissions, and combustion noise simultaneously, and the pilot injection condition affects the combustion process of the main injection and might affect the smoke reduction effect of the post injection. Thus this study aims at obtaining the post injection strategy to reduce smoke emissions in a diesel engine, where post injection is employed in combination with pilot injection. The experiments were performed using a single-cylinder diesel engine under various conditions of pilot and post injection with a constant load at an IMEP of 1.01 MPa, fixed speed of 1500 rpm, and NOx emissions concentration of 150 ± 5 ppm that was maintained by adjusting the EGR ratio. The injection pressure was set at 90 MPa at first, and then it was varied to 125 MPa to evaluate the effects of post injection on the smoke reduction in the case of higher injection pressure. The experimental results show that small post injection quantity with a short interval from the end of main injection causes less smoke emissions. And larger pilot injection quantity and later pilot injection timing lead to higher smoke emissions. And then, to explore and interpret the smoke emissions tendencies with varying pilot and post injection conditions, the experimental results of three-stage injection conditions were compared to those of two reference cases, which only included the pilot and main injection, and the interaction between main spray flames and post sprays was applied for analysis. Based on the comparative analysis, the larger smoke reduction effect of post injection was observed with the larger pilot injection quantity, while it is not greatly influenced by pilot injection timing. In addition, the smoke emissions can be reduced considerably by increasing the injection pressure, however the smoke reduction effect of post injection was attenuated. And all of these tendencies were able to be interpreted by considering the intensity variation of the interaction between main spray flames and post sprays.

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