Injection Valve Research Articles

REAL-TIME PARAMETRIC DIAGNOSTICS OF MARINE DIESEL ENGINES

Using modern high-performance microcontrollers with wireless interfaces, built-in ADC and low overall consumption, it is possible to develop a portable real-time parametric diagnostic system for marine engines. The system is based on the use of modern Android/iOS gadgets that receive information from sensors via Bluetooth and then make the necessary calculations and display charts and data in real time. The system being developed uses a combination of a gas pressure sensor in the working cylinder and a vibroacoustic sensor, which expands the diagnostic capabilities of marine diesel engines under operating conditions. This solution makes it possible to diagnose the fuel injection system, the valves control mechanism, as well as some other engine systems. In order to develop a portable diagnostic system for marine diesel engines, it is first necessary to solve the problem of analytically determining TDC, since such a system does not involve the use of special sensors for this. Parameters of irregular engine operation are considered, which can be calculated in real time using time diagrams of pressure and vibration. Methods for expressly assessing the stability of the functioning of the main engine systems by monitoring and analyzing a number of successive operating cycles are considered. To assess the unevenness of engine operation, a dispersion estimate of deviations of the main parameters is used. For a comprehensive assessment of engine stability in real time, the CII (cycle’s irregularity index) criterion is proposed. The assessment of fuel injection irregularity in the engine cylinder can be carried out by analyzing the phase fronts of the vibration signal of the injector. Coefficients for assessing the irregularity of fuel injection and gas distribution valves timing are also proposed, using dispersion analysis of vibrograms fronts. The data processing methods proposed in the article will make it possible to analyze the stability of operating cycles, as well as to perform optimal tuning of engine systems and monitor the results during operation.

Enhanced after-treatment warm up in diesel vehicles through modulating fuel injection and exhaust valve closure timing

Enhanced after-treatment warm up in diesel vehicles through modulating fuel injection and exhaust valve closure timing

Effect of silicon dioxide nanoparticles on the rheology properties of fresh and mechanically degraded hydrolyzed polyacrylamide polymer solutions

AbstractPartially hydrolyzed polyacrylamide is extensively utilized in enhanced oil recovery operations. However, its efficacy is compromised by mechanical degradation during transport through injection lines, valves, and reservoir, which leads to a reduction in the average molecular weight, diminishing the solution's viscosity and viscoelastic properties, critical for efficient oil displacement. In this investigation, we characterized the degree of mechanical degradation in HPAM solutions by evaluating shear and extensional rheological parameters preand post‐degradation. Mechanical degradation was induced by subjecting them to controlled flow through a valve featuring varying degrees of constriction and flow rates. Our results demonstrate a significant reduction in zero‐shear viscosity and high‐strain extensional viscosity of mechanically degraded solutions, with reductions of up to 64%. To mitigate this issue, we explored the incorporation of silica nanoparticles as a potential remedy for mechanical degradation. These nanoparticles strengthen the network structure of HPAM, thereby reducing its susceptibility to mechanical degradation. Our findings reveal that shear and extensional viscosities of mechanically degraded NPs‐HPAM solutions experienced only minimal reductions, dropping to 12% and 0%, respectively. This underscores the effectiveness of the nanoparticle‐enhanced HPAM solutions in preserving viscosity and viscoelasticity under mechanical stress, presenting a promising avenue for improving the robustness of EOR processes.

Experimental investigation on the potential of passive prechambers for use in 2S engines

Design improvement of Internal Combustion Engines (ICEs) is required by the continuous update of European exhaust emission standards and vehicle registration protocols. This has pushed research and industry efforts towards the development of Low Temperature Combustion (LTC) systems. Among various LTC technologies, the so called “jet ignition” is claimed to be well-suited for light engines, since it provides a more uniform and rapid combustion while ensuring the mixture ignition process. In this context, the adoption of prechambers was found well-suited for two-stroke engines, for which low-pressure direct injection technologies have been developed in the last decade to reduce the fuel short circuit phenomenon. The present paper experimentally investigates the use of different passive combustion prechambers in a Low-Pressure Direct Injection (LPDI) 2-stroke engine, with the main purpose to understand the relationship between prechamber geometrical parameters and engine performance. A 50-cc single cylinder LPDI motorcycle engine is chosen as the test case and it is re-arranged to run in jet ignition mode. The experimental analysis focuses on the evaluation of benefits provided by jet ignition combustion compared to the baseline LPDI propulsion unit at different engine operating points. Design criteria for prechambers development and the tuning process of engine combustion parameters (such as start of injection, ignition time and throttle valve opening) are described in detail. The results of experimental activity are finally shown and critically discussed, highlighting advantages and disadvantages of this application in terms of engine performance, efficiency and cycle-to-cycle variation.

Badania turbulentnego przepływu płynu w pompach głębinowych w celu poprawy bezpieczeństwa środowiskowego

When the plunger moves downwards, the local hydraulic resistance in the injection system causes a hydraulic force from the bottom upwards, which prevents the plunger from falling freely in the cylinder and is the source of the bending of the pump rod column. For this reason, the plunger takes an eccentric position in the cylinder and presses against it, delaying the plunger fall from the head of the balancer of the rocking machine and disturbing coaxial connection of the stock-discharge valve-plunger. These complications lead to increased wear of the plunger-cylinder pair, breakage of the injection valve cell, broken pump rod column, loss of the plunger stroke, etc. It should be noted, however, that in these tests, the flow factor μ is taken as the hydraulic resistance for determining the pressure loss in the valve assembly, and the valve seat cross-section is calculated. When calculating the friction force in the plunger-pressure valve system, the loss of pressure in it is taken to be equal to the loss of pressure of the valve unit. As is known, the downhole pump suction and injection system is a complex system of local resistance, as it consists of different combinations of elements that strongly affect the overall hydraulic resistance of the unit. It is therefore advisable to adopt the local hydraulic resistance coefficient as the hydraulic resistance of the respective unit. The reliability of downhole pumps in general and their individual components is ensured during their design and manufacture and depends on the design features, the quality of manufacturing of components thereof, assembly of the downhole pump in general and their components, as well as a number of other process indicators.

High-pressure liquid refrigerant injection for reciprocating compressors

Isentropic (adiabatic) compression of superheated vapor in vapor compression refrigeration cycles usually results in some discharge superheat, i.e. the discharge temperature exceeding the condensing temperature. Large discharge superheat reduces both operating range and compression efficiency. Sub-isentropic compression with heat rejection to the heat sink is therefore superior to adiabatic compression, as it results in lower discharge superheat and improved efficiency. However, significant temperature reduction by heat transfer through the working chamber walls is difficult to facilitate in common refrigeration compressors, particularly reciprocating compressors. Refrigerant and oil injection is a well-established method for reducing temperatures and increasing efficiency in screw and scroll compressors, as well as multi-stage systems. In comparison, effective methods for temperature reduction in single-stage reciprocating compressors are fairly limited. Therefore, a concept for high-pressure liquid injection is proposed. By means of a pump and injection valve, high-pressure liquid refrigerant is injected into the working chamber and atomized. The compressed gas is cooled through the evaporation of the injected liquid. The injection valve allows for control over the injection timing and quantity, enabling adjustment of the temperature profile, which is a major distinction from existing refrigerant injection methods. The coupled compression-injection process is evaluated for various refrigerants using an energetic chamber model. The injection is found to be particularly suitable for refrigerants with a large evaporation heat and a shallow dew line slope. For the example of ammonia, a theoretical reduction in compression work of 8.9% at an evaporation temperature of −10 °C and a condensing temperature of 45 °C is found.

High-Throughput Capillary Liquid Chromatography Using a Droplet Injection and Application to Reaction Screening.

The cycle time of a standard liquid chromatography (LC) system is the sum of the time for the chromatographic run and the autosampler injection sequence. Although LC separation times in the 1-10 s range have been demonstrated, injection sequences are commonly >15 s, limiting throughput possible with LC separations. Further, such separations are performed on relatively large bore columns requiring flow rates of ≥5 mL/min, thus generating large volumes of mobile phase waste when used for large scale screening and increasing the difficulty in interfacing to mass spectrometry. Here, a droplet injector system was established that replaces the autosampler with a four-port, two-position valve equipped with a 20 nL internal loop interfaced to a syringe pump and a three-axis positioner to withdraw sample droplets from a well plate. In the system, sample and immiscible fluid are pulled alternately from a well plate into a capillary and then through the injection valve. The valve is actuated when sample fills the loop to allow sequential injection of samples at high throughput. Capillary LC columns with 300 μm inner diameter were used to reduce the consumption of mobile phase and sample. The system achieved 96 separations of 20 nL droplet samples containing 3 components in as little as 8.1 min with 5-s cycle time. This system was coupled to a mass spectrometer through an electrospray ionization source for high-throughput chemical reaction screening.

A Numerical Simulation Approach for Superheated Steam Flow during Multipoint Steam Injection in Horizontal Well

Superheated steam flow during multipoint steam injection technology has a good effect on improving the steam absorption profile of heavy oil thermal recovery wells, enhancing the production degree of horizontal section of thermal recovery wells, and enhancing oil recovery. Based on the structure of multipoint steam injection horizontal string, considering the characteristics of variable mass flow, pressure drop of steam-liquid two-phase flow, and throttling pressure difference of steam injection valve in the process of steam injection, this paper establishes the calculation model of various parameters of multipoint steam injection horizontal wellbore and calculates the distribution of steam injection rate, temperature, pressure gradient, and dryness along the section of multipoint steam injection in horizontal wellbore. The results show that the temperature and pressure decrease gradually from heel to toe, and the steam dryness decreases gradually. Considering the influence of throttle pressure difference of steam injection valve and pressure drop of gas-liquid two-phase flow in the wellbore, the traditional calculation model of steam injection thermodynamic parameters is optimized, and the optimization of wellbore structure and steam injection parameters is an effective method to achieve uniform steam injection in horizontal wells. The steam injection uniformity of horizontal wells can be effectively improved by adjusting the steam injection valve spacing and steam injection parameters. When the steam injection volume is 200 m3/d and the steam injection valve spacing is 20 m, a more stable steam injection effect can be obtained. The findings of this study can help for better understanding of improving the uniformity of steam injection and enhancing the recovery factor.

Optimization of Structural Parameters of Piezoelectric Injection Valve Based on Model Experiment and CFD Simulation

The miniaturization of electronic devices requires a decreasing quality of adhesive points. In order to obtain the minimum defect free adhesive point for injection, this paper uses a combination of Taguchi experiment and CFD method to systematically study the influence of structural changes in the needle nozzle on the mass size of the adhesive point of the piezoelectric injection valve. The results indicate that the structural changes of the needle nozzle have a significant impact on the quality of the sprayed adhesive point. For the five types of needle and nozzle structures studied, when the nozzle size is 0.05mm and the needle size is 1.0mm, the adhesive produced by the injection valve is the smallest, and the minimum adhesive mass is 13.3% of the original injection valve (APJ1500) injection mass. Through CFD simulation, it was found that due to the smaller nozzle diameter of the optimal parameter combination during the valve opening stage, and the higher reflux ratio of the nozzle combination during the needle lowering stage, it can produce smaller adhesive mass.

Minimize Precolumn Band Broadening with Immiscible Solvent Sandwich Injection.

We investigated the possibility of reducing the effect of precolumn band broadening (PreCBB) by sandwiching the sample between two small plugs of an immiscible liquid. It has been found that in cases of severe PreCBB, improvements in peak efficiency can amount up to 20 times for the early-eluting compounds. For smaller degrees of PreCBB, the gain on the efficiency of early-eluting compounds is smaller (order of 50%), yet it is still significant. It has been verified that the presence of the immiscible fluid sandwich does not affect the repeatability of the analysis nor the linearity of the calibration curves used for analyte quantitation. It is also shown that the main effect of the two sandwich plugs is the minimization of the dispersion in the precolumn transfer tubing itself, which makes the method fundamentally different from pure on-column focusing methods such as the performance optimizing injection sequence (POISe) method. It is further demonstrated that both halves of the sandwich are needed, since the beneficial effect is clearly much smaller when only one plug is present. A drawback of the method is that some of the late-eluting peaks are slightly adversely affected by the presence of the sandwich liquid in the case where 127 μm i.d. tubing was used. The mechanism for this peak deterioration effect is at present still unclear but only occurs under gradient conditions and is clearly linked to the size of the sandwich plugs (the smaller the plugs, the smaller the adverse effect) and the internal diameter of the tubing used between the injection valve and the column.

Research on Surface Flaw Detection of Industrial Components Based on Deep Learning Algorithm

This paper primarily focuses on the research of industrial component surface defect detection algorithms using deep learning techniques. Taking the example of defect detection in the injector valve seat of automotive engine components, currently, the inspection of such small components heavily relies on manual visual inspection or traditional machine vision methods. Manual visual inspection is inefficient and cannot guarantee the speed and accuracy of detection. Traditional machine vision methods, while efficient, are sensitive to harsh environmental conditions and can be influenced by factors such as lighting, camera positioning, and background, resulting in poor robustness and limited feature extraction capabilities. To address these issues, this paper conducts research on a deep learning-based surface defect detection algorithm for injector valve seats.

Dew pressure point and liquid dropout of CH4 + alcohol (methanol or ethanol) system with high gas content at high-pressure and high-temperature

Hydrate inhibitor injection through gas-lift flow is used in production fields. The gas + inhibitor system's phase behavior provides essential information regarding monophasic regions and operational safety conditions. Methane is the main constituent of natural gas and is commonly used as a model component to represent gas reservoir fluids. However, pressure variation during a gas-lift injection can cause liquid dropout at valve injection. Therefore, phase behavior knowledge of methane + alcohol mixtures is potentially interesting in the oil and gas industry. In this work, dew pressure and liquid dropout data were experimental measured for methane + methanol (96.60 mol % CH4) and methane + ethanol (96.50 mol % CH4) systems in the temperature domain of 313.15 to 366.65 K and pressure up to 70 MPa. The CPA equation of state was used to correlate dew pressure and liquid dropout data for all systems, presenting a dew pressure absolute relative deviation of 6.89 and 5.22 % for methane + methanol (96.60 mol % CH4) and methane + ethanol (96.50 mol % CH4), respectively.

Combustion Process of the Compound Supply CNG Engine

Objective: In order to study the lean combustion process of a natural gas engine by separating the combustor, a spark ignition natural gas engine with separated combustors was retrofitted from a S195 single-cylinder diesel engine. Methods: The electronic control system controlled the gas supply and the spark plug ignition. A low pressure injection valve was set in the inlet pipe to form a lean mixture while a high pressure injection valve was placed in the subsidiary chamber to create a rich mixture, which was then ignited and injected into the main combustor, where the lean mixture was subsequently ignited again to achieve stratified combustion. Results: The test results showed that steady ignition is feasible in the system and verified the impact of the shape of the main combustor on HC, the impact of channel diameter on NOX production, and the impact of the ratios of high-pressure gas and low-pressure gas on HC and NOX. The combustion conditions of high-pressure gas and low-pressure gas in the engine combustor vary greatly. Our results signify that the shape of the main combustor has a great impact on the performance of the engine, that is, a shorter propagation distance can reduce the generation of HC. Conclusion: The best ignition advance angle under different conditions was determined using a spark ignition natural gas engine. The ratios of high-pressure gas and low-pressure gas greatly impact the performance and emission of the engine. The reduced diameter of the channels between the main and subsidiary combustors can enhance the stratification and facilitate the secondary ignition.

New Design Valve in Flow Injection System for the Determination of Pb(II) in Biological and Environmental Samples

A strategy to design an injection valve for a streamlined flow injection technique is described as speed and low-cost materials available in the environment for the determination of Pb(II) ion using the organic reagent 4-((4-methoxyphenyl)diazenyl)benzene-1,3-diol at a wavelength of 498 nm. The scope of the study is to find the optimal conditions, including the flow rate of the carrier, the dispersion coefficient, the length of the reaction coil, and the calibration drawing. The results showed that the optimum length of the reaction coil is 20 cm, and the optimum flow rate is 9.1 mL/min, which is equivalent to the pumping rate of 70 F/min. The range of linearity of the study was revealed by a calibration curve of 0.5–27 mg/L, slope = 1.507, correlation coefficient = 0.9995, the limit of quantitative (LOQ) = 0.088 mg/L, and limit of detection (LOD) = 0.026 mg/L. The system under study has a characteristic efficiency. The dispersion coefficient was calculated for concentrations of 10–15 mg/L Pb(II) ion. Furthermore, the accuracy of the flow injection technique in the estimation process was studied and compared with the Flame Atomic Absorption Spectroscopy (FAAS) technique.

Validation of analytical HPLC with post-column injection as a method for rapid and precise quantification of radiochemical yields

Accurate assessment of isolated radiochemical yields (RCYs) is a prerequisite for efficient and reliable optimization of labeling reactions. In practice, radiochemical conversions (RCCs) determined by HPLC analysis of crude reaction mixtures are often used to estimate RCYs. However, incomplete recovery of radioactivity from the stationary phase can lead to significant inaccuracies if RCCs are calculated based on the activity eluted from the column (i.e. the summed integrals of all peaks). Here, we validate a simple and practical method that overcomes problems associated with retention of activity on the column by determination of the total activity in the sample using post-column injection. Post-column injections were carried out using an additional injection valve, which was placed between the outlet of the HPLC column and the inlet of the detectors. 2-[18F]Fluoropyridine ([18F]FPy) and 8-cyclopentyl-3-(3-[18F]fluoropropyl)-1-propylxanthine ([18F]CPFPX) were prepared with radiochemical purities of > 99.8% and mixed with [18F]fluoride at a ratio of 1:1 to simulate reaction mixtures obtained by radiolabeling reactions with an RCC of 50%. The samples were analyzed on three different C18 HPLC columns using neutral and acidic mobile phases. RCCs determined using the summed area of all peaks in the chromatograms were compared with those determined using post-column injection. Additionally, RCCs determined by post-column injection were corrected for activity losses before, during and after radiosyntheses to afford analytical RCYs, which were compared with isolated RCYs. Determination of RCCs based on the summed area of all peaks gave correct results under certain chromatographic conditions, but led to overestimation of the actual RCCs by up to 50% in other cases. In contrast, determination of RCCs using post-column injection provided precise results in all cases, and often significantly reduced analysis time. Moreover, analytical RCYs calculated from RCCs determined by post-column injection showed excellent agreement with isolated RCYs (<3% deviation). In conclusion, HPLC analysis using post-column injection enables reliable determination of RCCs independent of the chromatographic conditions and, together with a simple activity balance, rapid and accurate prediction of isolated RCYs.

Fault Diagnosis in Gas Lift System Using PDF Data

Fault detection and isolation in the gas lift system were implemented assuming the gas lift variables are stochastic. Injection valve coefficient (Civ), production choke coefficient (Cpc), annulus pressure (Pa), and wellhead pressure (Pwh) were observed to show variations with faults presence. By simulating these gas lift variables as stochastic, the probability density function (PDF) data were used to generate decision functions for both the detection and isolation of the gas lift valve faults. The scheme accurately detected and isolated faults in the injection valve coefficient (Civ) and production choke coefficient (Cpc). The result of this diagnosis will aid the proper implementation of fault tolerant control in the gas lift system which will lead to its optimal operation.

Data-Driven Prediction of Key Combustion Parameters Based on an Intelligent Diesel Fuel Injector for Large Engine Applications

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;Digital technologies are capable of making a significant contribution to improving large internal combustion engine technology. In particular, methods from the field of artificial intelligence are opening up new avenues. So-called “intelligent” engine components rely on advanced instrumentation and data analytics to create value-added data, which in turn can serve as the basis for applications such as condition monitoring, predictive maintenance and controls. For related components and systems, these data may also allow for novel condition monitoring approaches. This paper describes the use of value-added data from an intelligent diesel fuel injection valve that give detailed information about the injection process for real-time prediction of key combustion parameters such as indicated mean effective pressure, maximum cylinder pressure and combustion phasing. These parameters are usually involved in combustion controls and power unit condition monitoring and normally acquired using in-cylinder pressure indication systems, which are costly and prone to wear. On the one hand, a data-driven model for key combustion parameters based on an intelligent fuel injection valve could replace an indication system. On the other hand, such a model may enable backup functionality and mutual condition monitoring of the fuel injection valve and the indication system. The data required for model building were acquired from a medium-speed four-stroke single-cylinder research engine with a displacement of approximately 15.7 dm&lt;sup&gt;3&lt;/sup&gt;. Different machine learning methods are compared to obtain an accurate yet reliable model for each of the desired combustion parameters. In addition to the value-added injection data, readily available parameters on production engines serve as model inputs (e.g., engine speed, charge air and exhaust gas pressures). Based on the results, the quality of the model predictions is evaluated, and it is assessed whether the approach might be useful for series engine applications.&lt;/div&gt;&lt;/div&gt;

Experimental Research and Numerical Simulation of Laser Welding of 303Cu/440C-Nb Stainless-Steel Thin-Walled Natural-Gas Injector for Vehicles.

This paper presents the results of research on laser lap welding technology of heterogeneous materials and a laser post-heat treatment method to enhance welding performance. The purpose of this study is to reveal the welding principle of austenitic/martensitic dissimilar stainless-steel materials (3030Cu/440C-Nb) and to further obtain welded joints with good mechanical and sealing properties. A natural-gas injector valve is taken as the study case where its valve pipe (303Cu) and valve seat (440C-Nb) are welded. Experiments and numerical simulations were conducted where the welded joints' temperature and stress fields, microstructure, element distribution, and microhardness were studied. The results showed that the residual equivalent stresses and uneven fusion zone tend to concentrate at the joint of two materials within the welded joint. The hardness of the 303Cu side (181.8 HV) is less than the 440C-Nb side (266 HV) in the center of the welded joint. The laser post-heat treatment can reduce the residual equivalent stress in the welded joint and improve the mechanical and sealing properties. The results of the press-off force test and the helium leakage test showed that the press-off force increased from 9640 N to 10,046 N and the helium leakage rate decreased from 3.34 × 10-4 to 3.96 × 10-6.

Hybrid Gas-Lifting Method Optimizes High-GOR Production

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 209721, “Hybrid Artificial Lift-SRP/Gas Lift for Oil Production in High-GOR Environments,” by Kuldeep Chanchlani, SPE, Ranjit Gogoi, and Sukumar Awasthi, SPE, ONGC, et al. The paper has not been peer reviewed. _ The casing gas-pressure-operated rod-lift (CGPORL) system described in the complete paper consists of a sucker rod, pump, gas-lift valves, downhole gas anchor, and tubing string. The completion was invented to save workover rig cost, reduce production deferments, and increase production efficiency in high-gas/oil-ratio (GOR) environments in marginal fields. CGPORL System Description The hybrid-lift system includes gas-lift and rod-lift modes, allowing operators to switch between two modes of artificial lift without costly workovers (Fig. 1). The key factor is the ability to isolate or communicate between the tubing and the annulus without pulling the tubing string out of the hole. Gas lift requires that the annulus should isolate tubing in order to inject gas through valves installed inside pocket mandrels, whereas rod pumps need communication between the tubing and annulus for passage of liberated free gas. Mechanism The gas-lift valve opens once annulus pressure develops over the valve-closing pressure. Once free gas is released into the tubing and the injection valve is closed, the annulus becomes a closed system. The free gas released from the downhole gas anchor gradually pressurizes the annulus until the valve opens for the next cycle. This mechanism indicates an intermittent gas-lift process in a cycle. When the well ceases to flow because of rod-lift failure, the well When the well ceases to flow because of rod-lift failure, the well will continue to flow through the annulus by keeping open the annulus valve connected to the nonreturn valve. Because of the nondevelopment of annulus pressure in case of rod-lift the CGPORL system. failure, a mobile air compressor can be used for valve unloading until the rod pump can be serviced. As the solution gas is recombined with liquid above the pump-setting depth, the hydrostatic head is relatively decreased. If the gas-lift valve is placed at a shallower depth, the drilled well length contributing to the reduction of fluid density is short. If the pump is placed at a deeper depth, annulus pressure can be high, so the gas-lift valve can be placed in a low position. Optimization for the point-of-pump setting and gas-lift-valve setting depth is required. These effects are related directly to the frequency of injection and rate, which must be examined along with economic and safety factors.

A hydrodynamic injection approach for capillary electrophoresis using rotor-stator valves.

Sample injection is a critical step in a capillary electrophoresis (CE) analysis. Electrokinetic injection is the simplest approach and is often selected for implementation in portable CE instruments. However, in order to minimize the effect of sample matrix upon the results of a CE analysis, hydrodynamic injection is preferred. Although portable CE instruments with hydrodynamic injection have been reported, injection has always been performed at the grounded end of the capillary. This simplifies fluidic handling but limits coupling with electrochemical detectors and electrospray ionization-mass spectrometry (ESI-MS). We demonstrated previously that injection at the high-voltage (HV) end of the capillary could be performed using an HV-compatible rotary injection valve (fixed-volume injection). However, the mismatch between the bore sizes of the channels on the rotor-stator valve and the separation capillary caused peak tailing and undesired mixing, impairing analytical performance. In this work, we present an HV-compatible hydrodynamic injection approach that overcomes the issues associated with the fixed-volume injection approach reported previously. The performance of the CE instrument was demonstrated by analyzing a mixture of 13 amino acids by CE coupled to laser-induced fluorescence, which showed relative standard deviations for peak area and migration time below 5% and 1%, respectively, for triplicate analysis. Additionally, replicate measurements of a mixture of amino acids, peptides, nucleobases, and nucleosides by CE coupled to electrospray ionization-mass spectrometry (CE-ESI-MS) were performed to evaluate peak tailing, and results were similar to those obtained with a commercial CE-ESI-MS setup.