scholarly journals Experimental Studies of Ethyl Acetate Saponification Using Different Reactor Systems: The Effect of Volume Flow Rate on Reactor Performance and Pressure Drop

2019 ◽  
Vol 9 (3) ◽  
pp. 532
Author(s):  
Ekaterina Borovinskaya ◽  
Valentin Khaydarov ◽  
Nicole Strehle ◽  
Alexander Musaev ◽  
Wladimir Reschetilowski
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Volume Flow Rate ◽  
Experimental Studies ◽  
Chemical Processes ◽  
Volume Flow ◽  
Reactor Performance ◽  
Flow Rates ◽  
Flow Energy ◽  
Mass And Heat Transfer

Microreactors intensify chemical processes due to improved flow regimes, mass and heat transfer. In the present study, the effect of the volume flow rate on reactor performance in different reactors (the T-shaped reactor, the interdigital microreactor and the chicane microreactor) was investigated. For this purpose, the saponification reaction in these reactor systems was considered. Experimental results were verified using the obtained kinetic model. The reactor system with a T-shaped reactor shows good performance only at high flow rates, while the experimental setups with the interdigital and the chicane microreactors yield good performance throughout the whole range of volume flow rates. However, microreactors exhibit a higher pressure drop, indicating higher mechanical flow energy consumption than seen using a T-shaped reactor.

Identification of Design Criteria for Converter Cooling System of Permanent Magnet Direct-Drive Wind Turbine Generator

2016 ◽  
Author(s):  
Gerardo L. Augusto ◽  
Alvin B. Culaba ◽  
Laurence A. Gan Lim
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Cooling System ◽  
Volume Flow Rate ◽  
Volume Flow ◽  
Design Criteria ◽  
Direct Drive ◽  
Turbine Generator ◽  
Wind Turbine Generator ◽  
System Volume

The design criteria of converter cooling system for a 2.5 MW permanent magnet direct-drive wind turbine generator were investigated. Two (2) distribution networks with pipe sizes of DN40 and DN50 were used as basis for fluid flow analysis. The theoretical system pressure drop and system volume flow rate of converter cooling system were calculated using the governing equations of mass conservation, pump performance curve and distribution network characteristics. The system of nonlinear equations was solved using multivariable Newton-Raphson method with the solution vector determined using LU decomposition method. Numerical results suggest that the DN50 pipe provides a pressure drop limit of less than 300 Pa/m in the converter cooling system better than the pressure drop obtained from a DN40 pipe. The system volume flow rate of DN50 pipe was found to be above the operating limit of heat exchanger requirement of 135.30 L/min which needs to dissipate heat with a minimum of 50 kW.

scholarly journals Effects of Arterial Pco2 and Cerebrospinal Fluid Volume Flow Rate Changes on Choroid Plexus and Cerebral Blood Flow in Normal and Experimental Hydrocephalic Cats

1983 ◽  
Vol 3 (3) ◽  
pp. 369-375 ◽  
Author(s):  
S. Nakamura ◽  
G. M. Hochwald
Keyword(s):  
Blood Flow ◽  
Cerebrospinal Fluid ◽  
Cerebral Cortex ◽  
Choroid Plexus ◽  
Flow Rate ◽  
Volume Flow Rate ◽  
Volume Flow ◽  
Brain Blood Flow ◽  
Choroidal Blood Flow ◽  
Flow Rates

The effect of changes in brain blood flow on cerebrospinal fluid (CSF) volume flow rates, and that of changes in CSF volume flow rates on brain blood flow were determined in both normal and kaolin-induced hydrocephalic cats. In both groups of cats, blood flow in grey and white matter, cerebral cortex, and choroid plexus was measured with 105Ru microspheres during normocapnia, and again with 141Ce microspheres after arterial Pco2 was either increased by 300% or decreased by 50%. Blood flow measurements were also made during perfusion of the ventricular system with mock CSF and repeated during perfusion with anisosmotic mannitol solutions to alter CSF volume flow rate. In 30 normal and 26 hydrocephalic cats, blood flow to the cerebral cortex, white matter, and choroid plexus was similar; only blood flow to the caudate nucleus was greater in normal cats. The weight of the choroid plexus from hydrocephalic cats decreased by 17%. Blood flow in the choroid plexus of all cats decreased by almost 50% following hypercapnia or hypocapnia, without a change in the CSF volume flow rate. There was no change in cerebral or choroidal blood flow when CSF volume flow rate was either increased by 170% or decreased by 80%. These results suggest that choroid plexus blood flow does not limit or affect the volume flow rate of CSF from the choroid plexus. CSF volume flow rate can be altered without corresponding blood flow changes of the brain or choroid plexus. Choroid plexus blood flow and the reactivity of both brain and choroidal blood flow to changes in arterial Pco2 were not affected by the hydrocephalus. The lower CSF formation rate of hydrocephalic cats can be attributed in part to the decrease in the mass of choroid plexus tissue.

Influence of two-phase suction injection on performances of the scroll refrigeration compressor with a high-temperature shell

2021 ◽  
pp. 095440892110302
Author(s):  
Shuaihui Sun ◽  
Wang Zhe ◽  
Li Liansheng ◽  
Bu Gaoxuan
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Flow Rate ◽  
Volume Flow Rate ◽  
Volume Flow ◽  
Coefficient Of Performance ◽  
Two Phase ◽  
Flow Rates ◽  
Injection Volume ◽  
Discharge Temperature

The two-phase suction injection can reduce the discharge temperature of scroll refrigeration compressors, which work under a high-pressure ratio. The heat transfer along the pipe axis from the shell affects the two-phase suction injection significantly for the compressor with a high-temperature shell. In this paper, the suction mixing and heat transfer model was developed to calculate the heat transfer along the pipe axis from the high-temperature compressor shell. Then the model was coupled with the two-phase compressor model to obtain the compressor performance under different suction injection volume flow rates. The compressor with two-phase suction injection was tested under different injection volume flow rates to validate the model. The results indicated that the discharge temperature decreased by 2 °C when the mass injection ratio increased by 1%. As the injection volume flow rates increased, the total mass flow rate increased due to the reduction of the specific volume of the suction fluid; the input work decreased because of the reduction of specific work and the improvement of the motor's electric efficiency. The cooling capacity decreased since the cooling capacity of the injection refrigerant was wasted for cooling the suction process and the compressor shell, especially at high injection volume flow rates. The coefficient of performance reached the maximum value at the injection volume flow rate of 0.015 m3·h−1 and became lower than the coefficient of performance without injection when the injection volume flow rate raised to 0.035 m3·h−1. Hence, the two-phase suction injection can reduce the discharge temperature efficiently at low injection volume flow rates with a slight improvement of coefficient of performance.

scholarly journals Designing and Optimising the Parameters of Micro Channels

2020 ◽  
Vol 8 (2S12) ◽  
pp. 71-76
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Thermal Resistance ◽  
Flow Rate ◽  
Volume Flow Rate ◽  
Convective Heat Transfer Coefficient ◽  
Volume Flow ◽  
Micro Channel ◽  
Micro Channels ◽  
Good Agreement

This paper documents the optimization of different parameters of micro channel heat sink which enhance the heat transfer. The objective is to find the major thermal resistance in micro channel and its effect on other parameters. Water is used as a coolant and the initial values of convective heat transfer coefficient and volume flow rate are 30000 W/m2K and 1 lpm respectively. Different graph are plotted between pressure drop,heat transfer co-efficient, pressure drop,thermal resistance and flow rate to finally achieve the optimized valus of channel width and height, hydraulic diameter, thermal resistance and pressure drop. The result achieved are in good agreement with the previous researches.

Three-dimensional multiphase flow modeling of membrane humidifier for PEM fuel cell application

2019 ◽  
Vol 30 (1) ◽  
pp. 54-74
Author(s):  
Seyed Ali Atyabi ◽  
Ebrahim Afshari ◽  
Mohammad Yaghoub Abdollahzadeh Jamalabadi
Keyword(s):  
Flow Rate ◽  
Volume Flow Rate ◽  
Three Dimensional ◽  
Cross Flow ◽  
High Volume ◽  
Volume Flow ◽  
Dew Point ◽  
Multiphase Model ◽  
Flow Rates ◽  
Content Type

Purpose In this paper, a single module of cross-flow membrane humidifier is evaluated as a three-dimensional multiphase model. The purpose of this paper is to analyze the effect of volume flow rate, dry temperature, dew point wet temperature and porosity of gas diffusion layer on the humidifier performance. Design/methodology/approach In this study, one set of coupled equations are continuity, momentum, species and energy conservation is considered. The numerical code is benchmarked by the comparison of numerical results with experimental data of Hwang et al. Findings The results reveal that the transfer rate of water vapor and dew point approach temperature (DPAT) increase by increasing the volume flow rate. Also, it is found that the water recovery ratio (WRR) and relative humidity (RH) decrease with increasing volume flow rate. In addition, all mixed results decrease with increasing dry side temperature especially at high volume flow rates and this trend in high volume flow rates is more sensible. Although the transfer rate of water vapor and DPAT increases with increasing the wet inlet temperature, WRR and RH reduce. Increasing dew point temperature effect is more sensible at the wet side is compared with the dry side. The humidification performance will be enhanced with increasing diffusion layer porosity by increasing the wet inlet dew point temperature, but has no meaningful effect on other operating parameters. The pressure drop along humidifier gas channels increases with rising flow rate, consequently, the required power of membrane humidifier will enhance. Originality/value According to previous studies, the three-dimensional numerical multiphase model of cross-flow membrane humidifier has not been developed.

scholarly journals A Novel Non-Intrusive Vibration Energy Harvesting Method for Air Conditioning Compressor Unit

2021 ◽  
Vol 13 (18) ◽  
pp. 10300
Author(s):  
Chuan Choong Yang ◽  
Noor Fiqri Razqi Bin Noor Hanafi ◽  
Noor Hazrin Hany Bt Mohamad Hanif ◽  
Ahmad Faris Ismail ◽  
Hsueh-Hsien Chang
Keyword(s):  
Flow Rate ◽  
Air Conditioning ◽  
Volume Flow Rate ◽  
Piezoelectric Sensor ◽  
Volume Flow ◽  
Vibration Energy ◽  
Compressor Unit ◽  
Flow Rates ◽  
Air Volume ◽  
Custom Made

The purpose of harvesting vibration energy is to obtain clean and sustainable energy by converting vibration energy from ambient sources into a voltage output. In this work, a piezoelectric sensor, PZT-5H is attached to a 3D printed and custom-made mounting to be placed at an air conditioning condenser unit, to harvest vibration energy. The configuration of the harvester is non-intrusive, in which the harvester did not intrude into compressor unit operation. Temperature (20 °C, 22 °C, and 24 °C) and air volume flow rates (3 levels of air volume flow rate at 245 L/second, 274 L/second, and 297 L/second) were taken into consideration in this investigation. An accelerometer was first used to investigate the optimum vibration frequency in Hertz, and six locations were identified. Next, the piezoelectric sensor was mounted at these six locations, and the output root-mean-square (RMS) voltage from the piezoelectric sensor was obtained. The analysis of variance (ANOVA) indicated that temperature and air volume flow rates factors were significant. It was found that the location identified with the highest amount of vibration at 830.2 Hz from accelerometer measurement, was also the highest amount of RMS voltage, at 510.82 mV, harvested by the piezoelectric, from the temperature of 20 °C and air volume flow rates at high level (air flow volume flow rate at 297 L/second). From this work, it is feasible to utilize this novel method of harvesting waste vibration energy from the air conditioning compressor unit.

scholarly journals Experimental Studies of Droplet Formation Process and Length for Liquid–Liquid Two-Phase Flows in a Microchannel

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1341
Author(s):  
Li Lei ◽  
Yuting Zhao ◽  
Wukai Chen ◽  
Huiling Li ◽  
Xinyu Wang ◽  
...  
Keyword(s):  
Formation Mechanism ◽  
Flow Rate ◽  
Volume Flow Rate ◽  
Scaling Law ◽  
Experimental Studies ◽  
Droplet Formation ◽  
Continuous Phase ◽  
Volume Flow ◽  
Dispersed Phase ◽  
Two Phase

In this study, changes in the droplet formation mechanism and the law of droplet length in a two-phase liquid–liquid system in 400 × 400 μm standard T-junction microchannels were experimentally studied using a high-speed camera. The study investigated the effects of various dispersed phase viscosities, various continuous phase viscosities, and two-phase flow parameters on droplet length. Two basic flow patterns were observed: slug flow dominated by the squeezing mechanism, and droplet flow dominated by the shear mechanism. The dispersed phase viscosity had almost no effect on droplet length. However, the droplet length decreased with increasing continuous phase viscosity, increasing volume flow rate in the continuous phase, and the continuous-phase capillary number Cac. Droplet length also increased with increasing volume flow rate in the dispersed phase and with the volume flow rate ratio. Based on the droplet formation mechanism, a scaling law governing slug and droplet length was proposed and achieved a good fit with experimental data.

Thermal Analysis of Micro Capillary Pumped Loop System

2009 ◽  
Author(s):  
Chin-Tsan Wang ◽  
Tzong-Shyng Leu ◽  
Jui-Ming Yu ◽  
Yuh-Chung Hu
Keyword(s):  
Thermal Analysis ◽  
Flow Rate ◽  
Volume Flow Rate ◽  
Volume Flow ◽  
Capillary Pumped Loop ◽  
Two Phase ◽  
Flow Rates ◽  
Injection Volume ◽  
Micro Channels ◽  
System Temperature

A Capillary Pumped Loop is a sort of “two-phase heat transport device”. In this study, the micro capillary pumped loop (MCPL) and temperature sensors embedded in the micro-channels were fabricated using MEMS technology. An open type of MCPL was applied to determine the thermal analysis of MCPL corresponding to different injection volume flow rates under the condition of constant heating power 20W. A series of experiments yielded numerous results and are as follows: first, a larger injection volume flow rate results in a lower system temperature. Second, the thermal bubbles begin to degenerate into smaller bubbles at Q volume = 2 μl/min. In addition, the phenomenon of slug flow is observed with increasing injection volume flow rates, especially for the case of Q volume = 15 μl/min. Although the temperature of MCPL was reduced with the injection volume rate, the MCPL possessed an almost constant temperature difference regardless of injection volume flow rate. These findings will be useful in determining the optimal design of MCPL.

Novel epoxy/anhydride alternatives for biological electron microscopy: Physical and performance characteristis of embed 812 and LX 112 in combination with NSA/NMA/DMAE

1989 ◽  
Vol 47 ◽  
pp. 1000-1001
Author(s):  
Joe A. Mascorro ◽  
Gerald S. Kirby
Keyword(s):  
Electron Microscopy ◽  
Flow Rate ◽  
Succinic Anhydride ◽  
Volume Flow Rate ◽  
Mass Density ◽  
Uranyl Acetate ◽  
Volume Flow ◽  
Base Resin ◽  
And Performance ◽  
Acid Anhydrides

Embedding media based upon an epoxy resin of choice and the acid anhydrides dodecenyl succinic anhydride (DDSA), nadic methyl anhydride (NMA), and catalyzed by the tertiary amine 2,4,6-Tri(dimethylaminomethyl) phenol (DMP-30) are widely used in biological electron microscopy. These media possess a viscosity character that can impair tissue infiltration, particularly if original Epon 812 is utilized as the base resin. Other resins that are considerably less viscous than Epon 812 now are available as replacements. Likewise, nonenyl succinic anhydride (NSA) and dimethylaminoethanol (DMAE) are more fluid than their counterparts DDSA and DMP- 30 commonly used in earlier formulations. This work utilizes novel epoxy and anhydride combinations in order to produce embedding media with desirable flow rate and viscosity parameters that, in turn, would allow the medium to optimally infiltrate tissues. Specifically, embeding media based on EmBed 812 or LX 112 with NSA (in place of DDSA) and DMAE (replacing DMP-30), with NMA remaining constant, are formulated and offered as alternatives for routine biological work.Individual epoxy resins (Table I) or complete embedding media (Tables II-III) were tested for flow rate and viscosity. The novel media were further examined for their ability to infilftrate tissues, polymerize, sectioning and staining character, as well as strength and stability to the electron beam and column vacuum. For physical comparisons, a volume (9 ml) of either resin or media was aspirated into a capillary viscocimeter oriented vertically. The material was then allowed to flow out freely under the influence of gravity and the flow time necessary for the volume to exit was recored (Col B,C; Tables). In addition, the volume flow rate (ml flowing/second; Col D, Tables) was measured. Viscosity (n) could then be determined by using the Hagen-Poiseville relation for laminar flow, n = c.p/Q, where c = a geometric constant from an instrument calibration with water, p = mass density, and Q = volume flow rate. Mass weight and density of the materials were determined as well (Col F,G; Tables). Infiltration schedules utilized were short (1/2 hr 1:1, 3 hrs full resin), intermediate (1/2 hr 1:1, 6 hrs full resin) , or long (1/2 hr 1:1, 6 hrs full resin) in total time. Polymerization schedules ranging from 15 hrs (overnight) through 24, 36, or 48 hrs were tested. Sections demonstrating gold interference colors were collected on unsupported 200- 300 mesh grids and stained sequentially with uranyl acetate and lead citrate.

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