Water Volumetric Flow Rate Research Articles

Influence of corrugated tube structure and flow rate on the hydrogen absorption performance of metal hydride reactor and structural optimization

The metal hydride bed (MHB) reactor is an effective instrument for storing hydrogen. However, thermal stress causes the cooling tube expansion inside the MHB. The long-term effects will lead to the failure of the cooling tube. To absorb the thermal stress and reduce the deformation of the cooling tubes, this article establishes an MHB reactor with corrugated cooling tubes to study its hydrogen absorption performance. The results prove that some parameters are adversarial and flow rate patterns are complex (such as extreme flow rate and insufficient flow rate) in the hydrogen absorption process of the corrugated tube MHB reactor, which makes it impossible to optimize the structure of the corrugated tube through the gradient method. Under the condition of a fixed corrugated tube volume of 3×10−6m3 and a cooling water volumetric flow rate of 0.5×10−4m3/s, the structural parameters of the corrugated tube are optimized by the Monte Carlo algorithm. According to the optimized results (N=8, ro=4.25 mm, ri=3.98 mm, do=3.17 mm, di=4.33 mm), the hydrogen absorption efficiency of the corrugated tube MHB reactor (reaction fraction 0.758) is 1.36 times that of the straight tube (reaction fraction 0.557) at 560 s. Thus, the corrugated tube can reduce thermal stress and improve the heat transfer effect. This research is beneficial in improving long-term stability, enhancing operational efficiency, and reducing the volume and weight of large MHB reactors.

Numerical modelling and experimental validation of dripping, jetting and whipping modes of gas dynamic virtual nozzle

PurposeThis study aims to develop an experimentally validated three-dimensional numerical model for predicting different flow patterns produced with a gas dynamic virtual nozzle (GDVN).Design/methodology/approachThe physical model is posed in the mixture formulation and copes with the unsteady, incompressible, isothermal, Newtonian, low turbulent two-phase flow. The computational fluid dynamics numerical solution is based on the half-space finite volume discretisation. The geo-reconstruct volume-of-fluid scheme tracks the interphase boundary between the gas and the liquid. To ensure numerical stability in the transition regime and adequately account for turbulent behaviour, the k-ω shear stress transport turbulence model is used. The model is validated by comparison with the experimental measurements on a vertical, downward-positioned GDVN configuration. Three different combinations of air and water volumetric flow rates have been solved numerically in the range of Reynolds numbers for airflow 1,009–2,596 and water 61–133, respectively, at Weber numbers 1.2–6.2.FindingsThe half-space symmetry allows the numerical reconstruction of the dripping, jetting and indication of the whipping mode. The kinetic energy transfer from the gas to the liquid is analysed, and locations with locally increased gas kinetic energy are observed. The calculated jet shapes reasonably well match the experimentally obtained high-speed camera videos.Practical implicationsThe model is used for the virtual studies of new GDVN nozzle designs and optimisation of their operation.Originality/valueTo the best of the authors’ knowledge, the developed model numerically reconstructs all three GDVN flow regimes for the first time.

Numerical Analysis of the Boiling Heat Transfer Coefficient in the Flow in Mini-Channels

Abstract This paper deals with boiling heat transfer in the flow of water through an asymmetrically heated horizontal rectangular mini-channel. The mini-channel was made by gluing three transparent glass plates and a copper block. Through the glass window, the variable along the length of the mini-channel two-phase flow structures were recorded to determine local values of the void fraction. Four resistance heaters were attached to the copper block, powered by direct current, generating the heat initiating the flow boiling inside the channel. During the experiment, the following were measured: water volumetric flow rate, inlet pressure with pressure drop, inlet and outlet water temperature, copper block temperatures at three points inside its body, voltage and current supplied to the heaters. Stationary and laminar fluid flow with low Reynolds numbers were assumed in the mathematical model of heat transfer in selected elements of the measuring module. The temperature distributions in the copper block and flowing water were described by the appropriate energy equations: the Laplace equation for the copper block and the Fourier–Kirchhoff equation with parabolic fluid velocity for the flowing water. These equations were supplemented with a set of boundary conditions based on measurement data; moreover, data from experimental studies were the basis for numerical calculations and their verification. Two-dimensional temperature distributions of the copper block and water were calculated with the Trefftz method (TM). The main objective of this study was to determine the heat transfer coefficient on the contact surface of the copper block and water, which was calculated from the Robin boundary condition. The results of the calculations were compared with the results of numerical simulations performed using the Simcenter STAR-CCM+ software, obtaining consistent values. Computational fluid dynamics (CFD) simulations were verified based on experimental data including void fraction and temperature measurements of the copper block and flowing water.

Closed loop liquid cooling of high-powered CPUs: A case study on cooling performance and energy optimization

This case study presents an experimental investigation of closed loop liquid cooling of CPUs. The cooling system implements a pumped liquid supplying a cold plate fixed to the emulated CPU heat source and a remote Air-Cooled Heat Exchanger (ACHE). The Hybrid Liquid-Air (HLA) system employs 25% v/v Arteco-Freecor with distilled water solution as the primary coolant, and air as the secondary coolant. The thermal-hydraulic performance of the system is characterized over a range of operating conditions, including CPU heat loads (12–72 W/cm2), water volumetric flow rates (0.5–8 L/min), and air velocities (1–3 m/s). In order to provide a performance frame of reference, evaluations were also conducted with a conventional air-based fan-fin CPU cooling system. The results indicate that the HLA system significantly outperforms the traditional air-cooled fan-fin system, with much lower CPU temperatures and feasible power levels exceeding 300 W. Additionally, the study highlights the importance of the liquid flow rate and fan speed on the overall cooling performance. Finally, an optimal combination of liquid and air flow rates is identified for minimum energy consumption. Overall, these findings support the conclusion that conventional air-cooling is reaching its theoretical limit and closed loop liquid cooling has the potential keep pace with the escalating power levels of modern CPUs. However, the additional energy cost of the cooling system should be carefully managed in order to maximize overall system Coefficient of Performance.

Numerical Investigation of the Hydrothermal Characteristics of Water Flow in Compound Microchannel Heat Sinks

In the present work, three-dimensional numerical simulations of laminar forced convection flow of water in unique compound microchannel heat sinks (MCHSs) were investigated using computational fluid dynamics (CFD) modeling. The newly proposed MCHS is made up of circular microchannels slotted from the top within a trapezoidal shape, and its cooling effectiveness was compared to that of traditional rectangular MCHS. Each MCHS under consideration has the same hydraulic diameter and heat transfer surface area. Water volumetric flow rates (Qin) with a wide range of values are used, ranging from 40 to 90 ml/min, with the fluid inlet temperature set to 20 oC. A constant heat flux boundary condition of 100 W/cm2 is supplied on the MCHS bottom. The results demonstrated that the inclusion of reentrant trapezoidal shapes can disrupt both hydrodynamic and thermal boundary layers, as well as accelerate fluid flow and mixing in the main flow, resulting in a significant heat transfer enhancement. Furthermore, at Qin=90 ml/min, the average Nusselt number (Nuavg) of compound MCHS increased by 2.16%, while total pressure drop and total thermal resistance decreased by 1.73% and 1.57%, respectively, when compared to the straight rectangular counterpart.

Steady-state interconnected cycle modeling and experimental results of a lab-scale ORC

ORC is one of the mature technologies for power generation from low temperature heat sources. In this study, the aim is to develop an accurate ORC model which is validated using reliable steady-state data. For this purpose, tests are carried out at four different heat source temperatures ranging from 80 to 110 °C to obtain data in a repeatable manner. The proposed model considers pressure drop and heat transfer correlations to improve the accuracy of model predictions. Using the refrigerant pump mass flow rate, thermal oil pump volumetric flow rate, cooling water inlet temperature, cooling water volumetric flow rate, the throttle valve outlet set pressure, and refrigerant pump outlet pressure as input, the model predicts the pressure, temperature, and mass flow rate in the cycle. The results show that the steady-state ORC model is significantly accurate, with ±1% deviations in pressure and ±1 °C in temperature, and ±5% in mass flow rate, heat transfer rate and refrigerant pump power predictions. The novel iterative model presented in this study includes pipe losses and significantly improves the simulation accuracy of ORCs with long pipes.

Performance Evaluation of a Triple Concentric Tube Heat Exchanger Using Deionized Water and Oil-40

This study examines experimentally the performance of a horizontal triple concentric tube heat exchanger TCTHE made of copper metal using water as cooling fluid and oil-40 as hot fluid. Hot fluid enters the inner annular tube of the TCTHE in a direction at a temperature of 50, 60 and 70 oC and a flow rate of 20 l/hr. On the other hand, the cooling fluid enters the inner tube and the outer annular tube in the reverse direction (counter current flow) at a temperature of 25 oC and flow rates of 10, 15, 20, 25, 30 and 35 l/hr. The TCTHE is composed of three copper tubes with outer diameters of 34.925 mm, 22.25 mm, and 9.525 mm, and thicknesses of 1.27 mm, 1.143 mm, and 0.762 mm, respectively. TCTHE tube's length was 670 mm. Nusselt number, overall heat transfer coefficient, convective heat transfer coefficient (CHTC), friction factor and pressure drop were measured from the obtained experimental results and plotted in graphs against Reynold number and volumetric flow rate of water. These parameters appeared good results in the cooling process. Nusselt numbers increased linearly with DIW flow rate for both C1 and C2 reaching maximum values of 38.25 and 14.64 respectively. CHTC increased linearly with the DIW flow rate for both C1 and C2 reaching maximum values of 2934.3 and 871.7 respectively. Overall heat transfer coefficient of DIW reached maximum values of 296.36 and 251.4 at 35 l/hr for C1 and C2, respectively. Friction factor DIW in C1 and C2 decreased with the volumetric flow rate increases, reaching minimum values of 0.04 and 0.25 respectively. Pressure drop of DIW increased linearly with flow rate reaching maximum values of 81.4 and 4.31 for C1 and C2 respectively. This in turn leads to reduced TCTHE length and size leading to a decrease in the construction cost of the heat exchanger.

Pressure Drop in Horizontal Two-Phase Flow

In an artificial environment, the most important key in the process equipment design is determining gas-liquid two-phase flow frictional pressure drop of pipes. To achieve this, an experimental investigation was carried out in this study to analyze the pressure drops of air-water two-phase flow in a 30mm internal diameter horizontal pipe with a length of 6m at different flow conditions. The study was carried out at 20Co using tap water and air. To cover the slug flow pattern, the volumetric flow rate of water varied from 30 to 80 LPM, and the volumetric flow rate of air from 40 to 200 LPM. Pressure transmitters were used to measure pressure at four different points along the test section, each 2m apart. The results of the experiments were compared to 8 models using 3 distinct methods: Mean Absolute Percentage Error (MAPE), Relative Performance Factor (RPF), and the percentage of data included in the range of the 30% error band. All methods produced similar results, with the Sun-Mishima model being the most accurate.

Laboratory Experiments on Performance Evaluation of Geocomposite Drainage Materials

Method of geocomposite drainage systems (GCDs) is relatively new and has been used as an alternative drainage system for geotechnical applications. The advantages of this system are cost- and time efficiency, environmentally sustainable, and at the same time, having comparable or higher drainage capability compared to current practices. However, the geocomposite materials, which is the main products of the GCD systems, need to meet certain criteria that are required for the sufficient drainage systems. These criteria are mainly related to their hydraulic and mechanical parameters that control the systems’ drainage capacity and durability during/after the construction. In this study, laboratory testing and evaluation of five different commercially available geocomposite products are conducted to improve the understanding of their physical, hydraulic and mechanical properties. Physical properties are defined by measuring their thicknesses and apparent opening sizes. Hydraulic parameters; permittivity (volumetric flow rate of water in normal direction) under various hydraulic head was measured using a constant-head equipment. Additional transmissivity and flow rate are defined under various hydraulic gradient and normal compressive stresses using in-plane flow rate testing apparatus. A number of strength testing; compressive strength, grab tensile strength, elongations, trapezoidal and puncture strength are conducted to evaluate the mechanical behavior of the geocomposite products. Results show that the parameters defined for each product are in the same order of magnitude in corresponding testing program, yet some differences are observed when compared with the manufacturer values. The reason of differences and recommendations on the selection of standard testing methods are discussed. Use of a factor of safety (FS) was suggested in the design of geocomposite drainage system when selecting the geocomposite materials.

Recovery of Spent Sulphuric Acid by Diffusion Dialysis Using a Spiral Wound Module.

In this study, we assess the effects of volumetric flow and feed temperature on the performance of a spiral-wound module for the recovery of free acid using diffusion dialysis. Performance was evaluated using a set of equations based on mass balance under steady-state conditions that describe the free acid yield, rejection factors of metal ions and stream purity, along with chemical analysis of the outlet streams. The results indicated that an increase in the volumetric flow rate of water increased free acid yield from 88% to 93%, but decreased Cu2+ and Fe2+ ion rejection from 95% to 90% and 91% to 86%, respectively. Increasing feed temperature up to 40 °C resulted in an increase in acid flux of 9%, and a reduction in Cu2+ and Fe2+ ion rejection by 2–3%. Following diffusion dialysis, the only evidence of membrane degradation was a slight drop in permselectivity and an increase in diffusion acid and salt permeability. Results obtained from the laboratory tests used in a basic economic study showed that the payback time of the membrane-based regeneration unit is approximately one year.

Analysis of Performance of the Wind-Driven Pulverizing Aerator Based on Average Wind Speeds in the Conditions of Góreckie Lake

In the introduction to this paper, the characteristics of Góreckie lake and the construction and operation of the wind-driven pulverizing aerator are presented. The purpose of this manuscript is to determine the efficiency of the pulverizing aerator unit in the windy conditions of Góreckie Lake. The efficiency of the pulverization aerator depends on the wind conditions at the lake. It was necessary to conduct thorough research to determine the efficiency of water flow through the pulverization segment (water pump). It was necessary to determine the rotational speed of the paddle wheel, which depended on the average wind speed. Throughout the research period, measurements of hourly average wind speed were carried out. It was possible to determine the efficiency of the machine by developing a dedicated mathematical model. The latest method was used in the research, consisting of determining the theoretical volumetric flow rates of water in the pulverizing aerator unit, based on average hourly wind speeds. Pulverization efficiency under the conditions of Góreckie Lake was determined based on 6600 average wind speeds for spring, summer and autumn, 2018. Based on the model, the theoretical efficiency of the machine was calculated, which, under the conditions of Góreckie Lake, amounted to 75,000 m3 per year.

The multivariable inverse artificial neural network combined with GA and PSO to improve the performance of solar parabolic trough collector

This work focused on presenting a multivariate inverse artificial neural network (ANNim) by developing two functions coupled to metaheuristic algorithms to increase a parabolic trough collector (PTC). This work aims to provide a new method capable of improving the thermal efficiency of a PTC by determining multiple optimal input variables. At first, two ANN models carried out to predict the PTC thermal efficiency (ηt), validated, and compared in detail. For that, six input parameters rim-angle (φr), inlet-temperature (Tin), ambient-temperature (Tamb), water volumetric flow rate (Fw), direct-solar-radiation (Gb) and wind-speed (Vv) considered as variables in the input layer. Two non-linear transfer functions (TANSIG and LOGSIG) in the hidden layer, a linear function (PURELIN) in the output layer, and the Levenberg-Marquardt training algorithm were applied. The results showed that both ANN models achieved satisfactory results with a coefficient of determination of 0.9511 and a root mean square error of 0.0193. Then, to get the variable's optimal values: rim-angle, inlet-temperature, and water volumetric flow rate, both ANN models inverted to acquire the multivariable objective function that could be resolved with genetic-algorithms (GA) and particle-swarm-optimization (PSO). The TANSIG function demonstrated better adaptation to the ANNim model by finding all the input variables in a random test with an error of 3.96% with a computational time of 14.39 s applying PSO. The results showed that by using the ANNim methodology, it is feasible to improve the performance of the PTC by optimizing from one, two, and three variables at the same time. In optimizing one variable at a time, it was possible to increase a random test's performance up to 54.78%, 27.62%, and 51.92% by finding the rim-angle inlet-temperature and water volumetric flow rate, respectively. In optimizing two variables simultaneously, it was possible to increase a random test's performance up to 36.73% by finding the appropriate inlet-temperature and water volumetric flow rate. In optimizing three variables simultaneously, it was possible to increase a random experimental test of up to 67.12%. Finally, the new ANNim method proposed may increase the thermal efficiency of a PTC in real-time because of the coupling of metaheuristic algorithms that allow obtaining optimal variables in the shortest possible time. Therefore, it can be a promising and widely used method for optimizing and controlling thermal processes.

An Experimental Study on New Multistage Solar Parabolic Trough Collector

Solar parabolic collector is a clean a promising traditional technique due to the deficiency in energy resources. A new designed multistage solar parabolic trough collector was proposed and its thermal performance was investigated in this study. The collector width and length are 1m with a copper receiver tube outside and inside diameters of 2.54cm, 2.46cm, respectively. Four buses tube receiver were proposed inside the parabolic collector fitted in a thermocouple at the entrance and exit regions of each bus. A solar tracker with a solar sensor for maximum collecting incident sun rays from the sun rise to sun set. The test section is covered with a glass sheet for easy cleaning and to protect the system from losing heat to the surrounding. To evaluate the thermal performance of the new collector, several variables were studied which are: temperature difference between the fluid inlet and outlet regions, heat absorbed by the collector, convective heat transfer rate, and collector thermal efficiency. All the studied variables show that minimum water volumetric flow rates will give max temperature difference between the fluid inlet and outlet regions, heat absorbed by the collector, convective heat transfer rate, and collector thermal efficiency respectively.

Testing Novel New Drip Emitter with Variable Diameters for a Variable Rate Drip Irrigation

This research presents a new variable rate drip irrigation (VRDI) emitter design that can monitor individual water drops. Conventional drip systems cannot monitor the individual water flow rate per emitter. Application uniformity for conventional drip emitters can be decreased by clogged emitters, irregular emitter orifices, and decreases in pressure. A VRDI emitter can overcome the irrigation challenges in the field by increasing water application uniformity for each plant and reducing water losses. Flow rate is affected by the diameter of the delivery pipe and the pressure of the irrigation delivery system. This study compares the volumetric water flow rate for conventional drip emitters and new VRDI emitters with variable diameters inner (1 mm, 1.2 mm, 1.4 mm, and 1.6 mm) and outside (3 mm, 3.5 mm, 4 mm, and 4.5 mm) with three pressures (34 kPa, 69 kPa, and 103 kPa). The tests revealed that the new VRDI emitter had flow rates that increased as the operating pressure increased similar to a conventional drip tube. The flow rate was slightly increased in the VRDI with pressure, but even this increase did not show large changes in the flow rate. The flow rate of the conventional drip tube was 88% larger than the VRDI emitter for all pressures (p < 0.05). However, operating pressure did not affect the drop sizes at the VRDI emitter, but the generalized linear mixed models (GLM) results show that volume per drop was impacted by the outside diameter of the VRDI outlet (p < 0.05). The interaction between the inner and outside diameter was also significant at p < 0.01, and the interaction between outside diameter and pressure was statistically significant at p < 0.01. The electronic components used to control our VRDI emitter are readily compatible with off-the-shelf data telemetry solutions; thus, each emitter could be controlled remotely and relay data to a centralized data repository or decision-maker, and a plurality of these emitters could be used to enable full-field scale VRDI.

Numerical and experimental analysis of a tube-and-fin cross-flow heat exchanger with a controlled non-uniform inflow of gas

The paper presents results of numerical and experimental analyses of a fin-and-tube air-water heat exchanger. The analysed device is a one-row heat exchanger with finned elliptical tubes. The aim of the analyses is to investigate the impact of a controlled non-uniform inflow of air on the heat exchanger performance. The heat exchanger was modelled numerically using the ANSYS Fluent program. The developed model was applied to simulate the heat exchanger operation in the conditions of the uniform inflow of air. Cases of an uncontrolled non-uniform inflow of gas were investigated experimentally, using a purpose-designed test station. On the experimental test station the effect of a controlled non-uniform air inflow was also achieved by placing appropriately shaped inserts in the air inlet duct, directing the air partially to the region of the water inlet header. By controlling the gas inflow, it was possible to significantly enhance the heat exchanger performance. The results of the multivariate numerical analyses conducted for the adopted parameters of the mediums (air and water volumetric flow rates and water temperature) show that the heat exchanger performance can be improved by up to almost 5% compared to a variant with a natural non-uniform air inflow taking place in the exchanger under consideration.

Influence of Pressure on Gas/Liquid Interfacial Area in a Tray Column

The influence of pressure on the gas/liquid interfacial area is investigated in the pressure range of 0.2–0.3 MPa by using a tray column test rig. A simulated waste gas, which consisted of 30% CO2 and 70% air, was used in this study. Distilled water was employed as an absorbent. The temperature of the inlet water was 19 °C. The inlet volumetric flow rate of water was 0.17 m3/h. Two series of experiments were performed; the first series was performed at inlet gas flow rate 15 Nm3/h, whereas the second series was at 20 Nm3/h of inlet gas flow rate. The results showed that the gas/liquid interfacial area decreases when the total pressure is increased. The effect of pressure on the gas/liquid interfacial area at high inlet volumetric gas flow rates is more significant than at low inlet volumetric gas flow rates. The authors studied the effect of decreasing the interfacial area on the performance of a tray column for CO2 capture.

OPTIMIZATION OF THE PERFORMANCE OF VAPOUR COMPRESSION CYCLE USING LIQUID SUCTION LINE HEAT EXCHANGER

One of the most commonly used refrigeration systems is vapour compression refrigeration system. As saving energy remains a challenge, researchers are putting a lot of efforts into finding efficient solution to improve the performance of vapour compression refrigeration systems. Mechanical subcooling and Liquid Suction Line Heat Exchanger (LSLHX) are approaches that have shown to improve the performance of Vapour Compression Cycle (VCC) systems. This experimental study is conducted to achieve two objectives. First objective is to optimize the heat source and heat sink water volumetric flow rate combination that results in the best performance. In order to evaluate the effect of using subcooling cycle and LSLHX cycle, different flow rate combinations are studied and analysed. Then, to optimize the heat source and heat sink water volumetric flow rate combination that outcome in the optimum performance. Second objective is to optimize the system performance through implementing subcooling and LSLHX. At the optimum water flow rates, the basic VCC performance of the designed system showed better performance compared to the published data. The system performance was improved by 10% at the optimum flow rate when solely subcooling was used while deteriorated by 47.5% at full LSLHX.

Analysis of the Theoretical Performance of the Wind-Driven Pulverizing Aerator in the Conditions of Góreckie Lake—Maximum Wind Speed Method

The eutrophication of surface waters is a natural process; however, anthropogenic activities significantly accelerate degradation processes. Most lakes in Poland and in the world belong to the poor and unsatisfactory water quality class. It is therefore necessary to limit negative anthropogenic impacts and introduce restoration methods, in particular those that are safe for the aquatic ecosystem. One of these is a pulverizing aeration Podsiadłowski method that uses only wind energy. The method allows for the moderate oxygenation of hypolimnion water, which maintains the oxygen conditions in the overlying water zone in the range of 0–1 mg O2·dm-1. The purpose of the work was to develop a new method of determining the efficiency of the aerator pulverization unit in the windy conditions of the lake. The method consists in determining the volumetric flow rates of water in the aerator pulverization unit, based on maximum hourly wind speeds. The pulverization efficiency in the conditions of Góreckie Lake was determined based on 6600 maximum hourly wind speeds in 2018. Based on the determined model, the theoretical performance of the machine was calculated, which in the conditions of Góreckie Lake in 2018 amounted to less than 79,000 m3 per year (nine months of the effective aerator operation).

Experimental testing for metrological traceability and accuracy of liquid microflows and microfluidics

Micro-flows are growing more important and useful for a wide variety of scientific and engineering fields such as bioanalysis, drug development and administration, Organ-on-a-Chip, etc, but accurate and reliable measurements traceable to the International System of Units can be challenging in micro-to-femto flow operating ranges. In this paper a gravimetric method has been used to quantify the measurement error of the volumetric flow rate of water from 1000 μL/h to 1 μL/h delivered by a syringe pump in different experimental conditions that replicate the current microfluidics setups. Several sources of error have been determined such as the mass measurement, the fluid evaporation dependent on the gravimetric methodology implemented and the repeatability, believed to be closely related to the operating mode of the stepper motor and drive screw pitch of the syringe pump. The elastic deformability of the medical grade 1 mL polypropylene syringes commonly used in micro-flows has greatly affected the volumetric flow rate, unlike the glass syringes tested. Finally, testing the gravimetric method while adding PDMS microfluidic channels to the flow circuit served to demonstrate that material, dimensions and shape of the microchannels did not show significant influence on the volumetric flow rate error for the flow rates imposed, important to establish well defined methodologies for microfluidics.

Effect of the Volumetric Flow Rate of Reaction Mixture Components on Nonoxidative Reforming of Methane with Admixed Water in Dielectric-Barrier Discharge

The effect of the volumetric flow rate of reaction mixture components on the nonoxidative reforming of methane with admixed water in dielectric-barrier discharge has been studied. An increase in the volumetric flow rate of water from 1.3 to 6 cm3/h did not exert a noticeable effect on the conversion of methane and on the concentrations of hydrogen and ethane in gaseous reaction products. An increase in the concentration of propane and butanes was observed, whereas the total ethylene and propylene content of the products decreased. An increase in the volumetric flow rate of methane from 5 to 60 cm3/min led to a decrease in the conversion of methane from 29.3 to 6.2 vol % and a decrease in energy consumption for its reforming from 88.3 to 34.7 eV/molecule, and it was also accompanied by a decrease in the rate of formation of gaseous alkanes and olefins. The experimental data confirmed previous conclusions on the reaction mechanism and kinetics of the nonoxidative reforming of methane in dielectric-barrier discharge, which were made using a mathematical model.