Injection Mode Research Articles

Experimental study on the fuel heating at the nozzle of the high pressure common-rail injector

In this study, an experimental and theoretical investigation of the fuel temperature increase at the nozzle of a common rail injector was conducted. The results showed that the temperature of the fuel at the nozzle began to increase rapidly with an increase in the injector working time and then stabilized. In the steady state, the temperature increase of the fuel at the nozzle holes only depended on the injection pressure drop rather than the discharge coefficient for the nozzle holes. The temperature increase of the fuel at the nozzle was not only related to the pressure drop but was also affected by the duty cycle of the injection pulse, which reflected the relative injection duration. The existing thermogenesis model for continuous flow is not suitable for the calculation of the temperature increase in the pulse injection mode of the common rail injector. A correction formula for the Joule–Thomson coefficient that considered the injection pulse and injection duration was proposed. The calculation results were in good agreement with the experimental data, which proved the accuracy of the model. These results and the mathematical model could be used to determine the thermodynamic boundary conditions inside a nozzle when using a three-dimensional method to calculate the thermodynamic state of the injector.

Hydraulically perfect modes of injection of grouting mixtures when isolating absorbing formations

The article deals with a mechanism of isolation of absorbing intervals during the construction of oil and gas wells. Research is based on systemic approaches to complex scientific and technical problems. The results of laboratory and technological experiments aimed at improving the hydromechanical processes of cementation of absorbing rocks are presented. Various technological schemes for injecting hardening solutions into intervals of absorbing formations, the mechanism of interaction between solutions and permeable rocks, hydraulically perfect modes of injection of backfill mixtures and quality and efficiency of insulation works are analyzed.

GRB spectrum from gradual dissipation in a magnetized outflow

ABSTRACT Modelling of many gamma-ray burst prompt emission spectra sometimes requires a (quasi) thermal spectral component in addition to the Band function that sometimes leads to a double-hump spectrum, the origin of which remains unclear. In photospheric emission models, a prominent thermal component broadened by sub-photospheric dissipation is expected to be released at the photospheric radius, $r_{\rm ph}\sim 10^{12}\,$ cm. We consider an ultra-relativistic strongly magnetized steady outflow with a striped-wind magnetic-field structure undergoing gradual and continuous magnetic energy dissipation at r < rs that heats and accelerates the flow to a bulk Lorentz factor Γ(r) = Γ∞min [1, (r/rs)1/3], where typically rph < rs. Similar dynamics and energy dissipation rates are also expected in highly variable magnetized outflows without stripes/field-reversals. Two modes of particle energy injection are considered: (a) power-law electrons, e.g. accelerated by magnetic reconnection, and (b) distributed heating of all electrons (and e±-pairs), e.g. due to magnetohydrodynamic instabilities. Steady-state spectra are obtained using a numerical code that evolves coupled kinetic equations for a photon-electron-positron plasma. We find that (i) the thermal component consistently peaks at $(1+z)E_{\rm pk}\sim 0.2-1\,$MeV, for a source at redshift z, and becomes sub-dominant if the total injected energy density exceeds the thermal one, (ii) power-law electrons cool mainly by synchrotron emission whereas mildly relativistic and almost monoenergetic electrons in the distributed heating scenario cool by Comptonization on thermal peak photons, (iii) both scenarios can yield a low-energy break, and (iv) the $\sim 0.5(1+z)^{-1}\,$ keV X-ray emission is suppressed in scenario (a), whereas it is expected in scenario (b). Energy-dependent linear polarization can differentiate between the two particle heating scenarios.

Synthesis of sodium nanoparticles for promising extraction of heavy oil

As reserves of conventional light oil become depleted, recovery of viscous oil is urgently needed to meet increasing energy demands worldwide before clean energy sources are fully developed. Current oil extraction technologies suffer from low efficiency, high cost, and environmental concerns. Attempts to use nanotechnology in this field have thus far been recognized to have only auxiliary effects, rather than playing a major role. Here we report a reactive sodium nanoparticle fluid able to in situ recover highly viscous crude oil very effectively even at room temperature. Its high recovery performance is based on a chemical reaction that allows the nanofluid to exhibit multiple benefits in displacing subsurface oil: heat, hydrogen gas, and sodium hydroxide. In addition, multi-stage nanofluid injection is found to be superior to a single injection mode. Thus, it opens a new way to extract and process crude oil.

Effect of Brown’s gas addition on combustion and emissions of homogeneous charge compression ignition engine

ABSTRACT The oxides of nitrogen (NO x ) and smoke emitted by widely used compression ignition (CI) engines of automobiles are among the major contributor to the environmental pollution. Several attempts are being made to reduce these exhaust emissions from automobiles. Low-temperature combustion (LTC) with homogeneous charge compression ignition (HCCI) is one of the strategies to reduce these engine exhaust emissions. The present work investigates the addition of Brown’s gas (HHO) in the intake manifold of a stationary common rail direct injection CI engine in HCCI mode. In the experiments, electronically assisted fuel injection system was used to maintain the injection pressure to 250 bars. The effect of HHO addition on the combustion and emissions was studied for different loads and injection advance. It was observed that the brake power, brake thermal efficiency, and brake-specific fuel consumption were improved by around 5% due to HHO addition. However, they were found to be decreased with increased injection advance. Moreover, a considerable reduction in NO x emission, i.e., 1–12 ppm was recorded for early injection mode. Thus, Brown’s gas addition with LTC strategy may result in reduced environmental pollution.

Effect of cavity-air injection mode on the performance of a trapped vortex combustor

The cavity has been widely used in subsonic and supersonic flows for flame stabilization. Moreover, significant efforts have been put on the combustion and flow characteristics of the cavity under a variety of cavity-air injection strategies. However, few attentions have been paid so far on the cavity-air injection mode. In this paper, experimental and numerical studies were conducted to investigate the effect of the cavity-air injection mode on the combustion and flow characteristics of a trapped vortex combustor (TVC). The present work was performed under atmospheric pressure with an inlet temperature of 473 K. The effects were directly explored in terms of ignition, lean blowout limit, combustion efficiency, cavity flow field, and turbulence intensity with an injection hole and an injection slit, respectively. The experimental results indicated that the ignition performance, lean blowout limit, and combustion efficiency depend highly on the cavity-air injection mode. The injection slit exhibited excellent advantages in terms of ignition performance and lean blowout limit as compared to those of the injection hole. However, the injection hole showed prominent superiority in combustion efficiency as compared to that of the injection slit. The simulation results based on Reynolds-averaged Navier-Stokes (RANS) showed that the significant discrepancies in combustion performance may mainly attribute to the different flow characteristics of the two injection modes.

Offline Selective Extraction Combined with Online Enrichment for Sensitive Analysis of Chondroitin Sulfate by Capillary Electrophoresis

A capillary electrophoresis (CE) method combined with online and offline enrichment for improving the detection sensitivity of chondroitin sulfate (CS) is established. The online enrichment method is based on the field-amplified sample stacking and large volume electrokinetic injection, and offline enrichment is based on the association between cetyltrimethylammonium chloride and CS. Experimental parameters affecting CE method such as the type and pH of background electrolyte, the injection mode and time and the steps of offline enrichment were optimized. Under optimum conditions, the calibration plot between CS concentration and peak area was linear in the range of 1~100μg/mL. The enrichment factor was 130 times and the limit of detection was 50ng/mL. The average recovery was 103.5% and the relative standard deviation of peak area was <2.0%. The method was successfully applied to the quantitative analysis of CS in drugs.

Heat transfer of flow past a cylinder with a slit

This study aimed to determines the heat transfer for flow past a cylinder with a slit. The flows past a cylinder with a slit at different angles of inclination were simulated to determine the effect of the inclination of the slit on the flow pattern and heat transfer. The results show that the slit increases the local Nusselt number and the average Nusselt number for a cylinder. At regimes of higher Reynolds number, there is a significant increase in heat transfer caused by the slit. In terms of increasing the local heat transfer coefficient, the injection mode is more effective than the blowing/suction mode However, the average heat transfer coefficient has a maximum value when the angle of inclination of the slit approaches a critical angle.

Transient model and its application to investigate the injection mode and periodical operation of transpiration cooling with liquid coolant phase change

To study the stability and reliability of transpiration cooling with phase change in complicated and changeable thermal environment, this paper suggests a transient mathematical model and numerically investigates the dynamic evolution of phase change and transient behavior of fluid–structure coupling heat transfer under three typical time-varying thermal environments. First, the feasibility and reliability of two coolant injection methods are analyzed and compared. The results indicates that the coolant injection based on pressure control is stable only when the heat flux imposed on transpiration cooling structure is relatively low and phase change occurs at hot side, while the coolant injection based on mass flow rate control is absolutely stable no matter how the external thermal environment changes. Then, the effects of fluctuated operation condition on the cooling performance of system and the transport characteristic of coolant are further studied. Although without affecting the stability of the transpiration cooling system in the long term, the fluctuation of coolant injection and external heat flux will result in the fluctuation of structure temperature and coolant driving force, and thereby cause significant deterioration of cooling performance, which will increase the ablation risk and coolant driving cost of transpiration cooling system.

Utilization of the Planar Laser-Induced Fluorescence Technique (PLIF) to Measure Temperature Fields in a Gas-Stirred Ladle

A 1/17th water physical model of a 200-ton steel ladle furnace with a single gas injection was used to simulate bath heating using a single burner to mimic the heat flux due to electric arcs in the industrial steel ladle. Two phases were considered, using water to simulate the molten steel and air to simulate the argon injection at a flow rate of 1.54 NL min−1. The planar Laser-Induced Fluorescence (PLIF) technique was for the first time experimentally implemented to measure temperature fields in a longitudinal plane of the gas-stirred ladle model. PLIF employs a laser source of 532-nm wavelength to light water seeded with rhodamine B, which emits fluorescence depending on its temperature, after a complex calibration is made. Next, the fluorescence is captured by a camera with a 550-nm wavelength filter. The PLIF measurements were validated by local thermocouple measurements at five different locations in the measurement plane. Temperature fields measured by PLIF are in good agreement with those obtained locally by thermocouples, so the PLIF technique can be used to measure temperature fields with the advantage of getting a complete temperature contour field, in contrast to point values of temperatures with thermocouples. Experiments were carried out to study the thermal mixing for two common tuyere positions, i.e., axisymmetric and eccentric (mid-radius) positions. Results on the injection mode show that axisymmetric gas injection is a more efficient heat transfer configuration between the burner and the liquid phase than is the symmetric injection mode for the particular heating configuration studied in this work.

Capillary liquid chromatography as an effective method for the determination of seven neonicotinoid residues in honey samples.

A new analytical method based on capillary liquid chromatography with diode array detection has been developed for the simultaneous quantification of seven neonicotinoid insecticides commercially available (imidacloprid, thiacloprid, clothianidin, thiamethoxam, acetamiprid, nitenpyram, and dinotefuran) in honey samples. The separation was achieved in a Zorbax XDB-C18 column (150×0.5mm id, 5μm), with a mobile phase consisting of ultrapure water (solvent A) and acetonitrile (solvent B) at a flow rate of 10 μL/min. Capillary column was thermostated at 25°C during the analysis and 254 or 270nm was established as detection wavelength, depending on the analyte. Furthermore, full loop injection mode (8 μL) was selected, using water as injection solvent. Finally, the optimized method was applied to the analysis of neonicotinoid residues in honey of different floral origins using dispersive liquid-liquid microextraction as sample treatment. Variables affecting the extraction efficiency were optimized, choosing methanol and dichloromethane as dispersive and extraction solvents, respectively. The method was characterized in terms of linearity ( ≥ 0.9948), repeatability, reproducibility (relative standard deviation below 4.5 and 6.3% respectively), and recoveries (≥80.5%). Detection and quantification limits were lower than 6.6 and 22.0μg/kg for the studied analytes, respectively.

A tube-in-tube membrane microreactor for tertiary treatment of urban wastewaters by photo-Fenton at neutral pH: A proof of concept

This work presents a disruptive approach to promote highly-efficient photo-Fenton process at neutral pH under continuous mode operation. The system consists of a tube-in-tube membrane reactor designed for continuous-flow titration of low iron doses to the annular reaction zone (ARZ). A concentrated acidic ferrous ion (Fe2+) solution is fed by the lumen-side of the membrane, permeating through the membrane pores (inside-out mode), being dosed and uniformly delivered to the membrane shell-side. Polluted water, containing amoxicillin (AMX) and oxidant (H2O2), flows continuously in the reactor annulus (space between the membrane shell-side and an outer quartz tube). The catalyst radial dispersion is enhanced by the helicoidal movement of water around the membrane shell-side, efficiently promoting its contact with H2O2 and UV light. The efficiency of photochemical and photocatalytic oxidation was evaluated as a function of catalyst dose, catalyst injection mode (radial permeation vs injection upstream from the reactor inlet), light source (UVA vs UVC) and aqueous solution matrix (synthetic vs real wastewater). At steady-state, photo-Fenton reaction with Fe2+ radial addition, driven by UVC light, showed the highest AMX removal for synthetic (∼65%, removal rate of 44 μMAMX/min, using [Fe2+]ARZ = 2 mg/L and [H2O2]inlet = 10 mg/L) and real municipal wastewaters (∼45%, removal rate of 31 μMAMX/min, with [Fe2+]ARZ = 5 mg/L and [H2O2]inlet = 40 mg/L), with a residence time of only 4.6 s.

HS-SPME-GC-MS as an alternative method for NDMA analysis in ranitidine products

N-nitrosodimethylamine (NDMA) is a carcinogenic contaminant that was accidentally discovered in drugs, such as valsartan and ranitidine, and more recently in metformin. Liquid chromatography tandem mass spectrometry (LC–MS/MS) is the method typically used for the analysis of NDMA in ranitidine. It seems that using gas chromatography (GC) for NDMA analysis is problematic as ranitidine is sensitive to high temperatures. In the present study, we assessed the usefulness of solid-phase microextraction (SPME) as a method of extraction and introduction into the GC. When using headspace (HS) and liquid injection modes in GC for NDMA analysis in ranitidine, higher NDMA levels were detected compared to using LC–MS/MS. Interestingly, using HS-SPME-GC–MS was advantageous because we could avoid the high temperature utilized in the liquid injection and HS modes. Moreover, the results obtained using HS-SPME-GC–MS provided a good match with those achieved using LC–MS/MS. The feasibility of using HS-SPME-GC–MS to successfully analyze NDMA in ranitidine opens new opportunities for the analysis of this contaminant in pharmaceuticals, specifically those that are heat-labile.

Abstract 5484: Influence of the thermal and electric properties of biological tissues on the maximum temperature during TTFields therapy

Abstract Tumor Treating Fields (TTFields) is a non-invasive technique used in the treatment of glioblastoma. It consists in applying an electric field with a frequency of 200 kHz in two perpendicular directions alternately. This technique has an anti-mitotic effect if the induced field is at least 1 V/cm at the tumor bed. The Optune device, used to deliver these fields in real subjects, controls the injected current to keep scalp's temperature below potentially harmful values by controlling the temperature of the transducers. The thermal impact of this technique was recently predicted by our group. In this work we aim to investigate how the uncertainties regarding both the electric and thermal properties of tissues, transducers and gel affect the maximum temperature reached by each tissue and might affect the time that the device is applying the fields due to its thermal restrictions. We used a realistic head model created from MR images to perform our studies and run the simulations in COMSOL Multiphysics. After an extensive literature review, we selected a reasonable range of values for each property and performed a one-way sensitivity analysis. To obtain the temperature distribution we solved Pennes' equation in frequency domain studies. We observed that the most significant electric parameters are scalp, skull and gel's conductivity values. In general, an increase in the conductivity led to higher temperatures, as expected. In terms of changes in the temperature reached by the transducers it was seen that it can vary between +1.3°C (when scalp's conductivity is increased by a factor of 80% to 0.45 S/m) and -1.7°C (scalp's conductivity decreased to 0.14 S/m). The thermal parameters that are more critical are the ones that can directly change how quickly heat is transferred to the environment, namely scalp's properties. Transducer temperature varied between -0.6°C and +1.3°C when scalp's thermal conductivity was increased by 46% and decreased by 53%, respectively. Furthermore, the sweat rate and the convection factor and emissivity of the medical tape that covers the arrays also led to significant temperature variations. The latter analysis can be used to study new types of materials that can be more appropriate to apply these fields. The remaining electric (relative permittivity) and thermal (metabolic heat, blood perfusion, blood density and specific heat and thermal conductivity of skull, CSF and brain) parameters did not lead to significant temperature variations. These results show the importance of precisely knowing the most crucial physical properties in TTFields modelling studies. Due to the very strict current control injection mode of Optune based on the temperature of the transducers, it would be beneficial to experimentally measure the properties here discussed. Citation Format: Nichal Gentilal, Pedro Cavaleiro Miranda. Influence of the thermal and electric properties of biological tissues on the maximum temperature during TTFields therapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5484.

Energy recovery enhancement from gas hydrate based on the optimization of thermal stimulation modes and depressurization

Natural gas hydrate is a potential and clean energy with abundant reserves in marine and permafrost areas. Efficient and safe extraction of the methane gas from gas hydrates has aroused worldwide attentions. In this work, the hydrate dissociation and gas production performances have been investigated in a high pressure reactor using two vertical wells by depressurization and its combinations with different injection modes, including warm water injection, room-temperature water flooding, and electric heating. The external heat supply rate is set identical in the cases with thermal stimulation. Results show that direct electrical heating combined with depressurization can dramatically increase the deposit temperature and eliminate the heat loss in the pipelines during fluid transportation, but a limited heat transfer radius exists in the vicinity of the heated wellbore due to the low thermal conductivity of the porous media. For the case with warm water injection, thermal convection becomes the key factor governing the heat transfer process, while the heat loss is inevitable during the transportation of the injected water in the pipelines. However, the heat can be more efficiently transferred to the hydrate-undissociated region through the water movement by enforced thermal convection than the electric heating. Comparatively, the novel tripartite strategy of electrical heating, room-temperature water flooding and depressurization shows the advantages of simultaneously reducing heat loss and enhancing heat transfer during hydrate exploitation, which results in the best energy recovery efficiency in this study. It suggests a good commercial exploitation value and shows important practical significance for future field studies.

Maxillary Lateral Incisor Injection Pain Using the Dentapen Electronic Syringe

IntroductionWhen patients express fear and anxiety about dentistry, 1 main source involves the administration of local anesthetic. The Dentapen (Septodont, Lancaster, PA) is a computer-controlled local anesthetic device that regulates the rate of anesthetic deposition to reduce pain associated with dental injections. The purpose of this study was to evaluate differences in perceived pain during the administration of local anesthesia of the maxillary lateral incisors using the ramp-up and continuous injection modes of the Dentapen. MethodsThis study used a randomized, controlled, double-blind, crossover, experimental design. The investigators randomly assigned the order of the teeth (#7 or #10) and the 2 delivery modes (continuous or ramp-up). Participants completed a Corah dental anxiety scale at each visit and were injected on 2 separate visits at least 2 weeks apart. After each injection, participants rated their perceived pain using a Heft-Parker visual analog scale at needle insertion, needle placement, and solution deposition. Repeated measures analysis of variance was used to determine differences in perceived pain between the 2 modes. ResultsThe data from 116 participants were analyzed. The perceived pain at deposition with the ramp-up mode (mean = 51.98, standard deviation = 30.04) was less than the continuous mode (mean = 59.98, standard deviation = 36.28) although not statistically significant (F1230 = 2.569, P > .05). Clinically, the perceived pain with the ramp-up mode was in the mild range (<54 mm), whereas the mean perceived pain with the continuous mode was in the moderate/severe range (>54 mm). ConclusionsFurther research should evaluate whether the ramp-up mode could be used to reduce the pain perceived with other dental injections.

Comparative study of different injection modes on combustion and particle emission of acetone-butanol-ethanol (ABE) and gasoline in a dual-injection SI engine

With the depletion of fossil energy and the aggravation of environmental pollution, using ABE as an alternative fuel in engines has become a research hotspot. In this paper, we conducted an experiment on a dual-injection spark ignition (SI) engine to compare three injection modes of ABE port injection plus gasoline direct injection (A + G), gasoline port injection plus ABE direct injection (G + A) and gasoline port injection plus gasoline direct injection (G + G) at different λ, engine speed, load and ignition timing. The results show that the torque of G + A mode is the highest at different engine speed, load and λ. CA0-90 of G + A and A + G are basically the same and lower than that of G + G mode, and CoVIMEP of G + A mode is lowest at each ignition timing. Besides, the G + A mode owns the highest BTE and is 0.2%, 0.4%, 0.02%, 0.05 and 0.6% higher than that of G + G mode at λ = 0.9 to 1.3, respectively. For gaseous emissions, NOx and HC emissions of G + A mode are the lowest under all the conditions. G + A mode owns the lowest CO emissions at λ = 0.9, 1.0 and 1.1, and all the CO values are lower than 0.1 vol% at λ = 1.2 and 1.3. For particle emissions, the G + A mode shows extremely low emissions under different engine speed, load and λ. The particle number of G + A shows unimodal distribution while the particle number of G + G and A + G modes shows the bimodal distribution. Overall, gasoline port injection plus ABE direct injection is the best injection approach for ABE/gasoline dual-fuel engine.

Design study of multi-charge low energy beams transport for BISOL post accelerator

Beijing Isotope-Separation-On-Line Neutron-Rich Beam Facility (BISOL) post accelerator is designed to accelerate RIBs extracted from Isotope Separation On-Line (ISOL) ion source and the beam energy will be upto 150 MeV/u for Stannum. The accelerated RIBs will be served as projectile to produce isotopes far from stable line. Multi-charge state beams transport is adopted to increase beam current, a low energy beam transport (LEBT) line is desired for selecting charge states, bunching beam from continuous wave (CW) ISOL beams and match the beam into a CW 81.25 MHz radio frequency quadrupole (RFQ). This paper mainly presents the design study of BISOL multi-charge LEBT line. The detailed optics design and beam dynamics simulation are presented. Due to lower beam energy (3 keV/u) and higher transverse emittance (0.2n,rπmmmrad), the longitudinal nonlinear effect in the bunching system cannot be ignored compared to existing LEBT bunching systems, we have investigated two novel bunching and injection modes (180∘@20.3125 MHz, 270∘@20.3125 MHz) as well as the traditional mode (180∘@40.625 MHz) to optimize the output longitudinal emittance. The beam dynamics analysis indicates that the output longitudinal rms emittance can be lowered by nearly 33% with the bunching mode of 270∘@20.3125 MHz compared to traditional mode. The detailed results are presented in this paper.

Influence of the technological mode of injection molding on the properties of nanocomposites based on linear low density polyethylene and natural minerals

The results of the study of the influence of temperature and pressure of injection molding on the properties and volume shrinkage of nanocomposites based on linear low-density polyethylene and natural mineral fillers are presented. A copolymer of ethylene with butylene, a copolymer of ethylene with hexene, and such natural Azerbaijan minerals as vesuvianite and clinoptilolite were used as raw materials.

IMPROVING THE EFFICIENCY INTO THE IMPACT FLUID FRACTURING BY ADAPTING IT TO THE PARAMETERS OF THE ENCLOSING ENVIRONMENT

The principle of formation of the oriented crack by displacement of a plastic substance from the well in the mode providing coincidence of frequency of influence on a plastic substance and natural frequency of oscillations of the host medium is discussed. The technical solution of adaptation of the mode of injection of a plastic substance into the formed crack to the changing parameters of the host medium is given. The means of implementation of this technical solution and the results of engineering calculations of their main components are presented.