ABSTRACT
A gas flowmeter for measuring low flow rate has been widely used in the field of medical, health, environmental protection, energy industry, aerospace, etc. To against Covid-2019, the requirement on the low flow rate has been increasing dramatically. At present, the typical standard devices for calibrating low gas flowmeter mainly include standard bell provers of gas flow, standard piston provers of low gas flow and standard laminar of low gas flow. Different measuring principles are adopted among these typical standard devices. To ensure the consistency of these typical standard devices, a comparison test is performed. The standard devices used in the comparison are of the same accuracy grade, with an extended uncertainty of 0.2%(k=2). The piston-type gas flow calibrator of grade 1.0 is selected as the transfer standard, and three flow points with high flow rate, medium flow rate and low flow rate are selected for test. The consistency of measurement results is evaluated by normalized deviation En. The comparison results are acceptable which show that three typical standard devices are accurate and reliable. © FLOMEKO 2022.All rights reserved
ABSTRACT
Mechanical ventilators and high-flow machines are medical devices with important measuring instruments for monitoring patients with respiratory failure. The most common monitoring parameters are lung proximal pressure, inspiratory flow, expiratory flow, inspiratory oxygen fraction, etc. The present work delves into the design, fabrication, and experimental measurement of a proximal flow sensor based on the theory of capillary tubes and stereolithography. The design was carried out in Inventor Professional 2020 software and then the computational study by CFD ANSYS to compare the dynamic pressure states of the geometric measurement points. The manufacturing was carried out using SLA 3D printing technology on an ANYCUBIC FHOTON MONO X.The fabricated FM SLA prototype has radially positioned latex tubing lines to achieve differential pressure measurement at two points separated by capillary tubes. These hoses are connected to a developmental embedded system based on a HONEYWELL 001PG7A5 differential pressure sensor and Arduino Uno Microcontroller. Finally, experimental tests of the Flow Meter Stereolithography (FM SLA) protype measurements were performed with flow rates from 0 to 44.5 lpm in 1 lpm increments. From the collected data we have an R2: 0.9983 in quadratic polynomial approximation with the actual measurement data. © 2022 IEEE.
ABSTRACT
Water distribution network (WDN) is a human-centered infrastructure that is indispensable for modern cities worldwide. In addition to optimizing the operation and management (O&M) of WDNs under the current state, water utilities should be able to manage uncertain and risk conditions for improving their O&M efficiency. Although the disintegration of large WDNs into permanent district metered areas (DMAs) is an O&M innovation based on water leakage monitoring and pressure management, its network redundancy and reliability diminish under anomalous conditions. Therefore, this study proposed a design and operation procedure to obtain optimal, self-adaptive DMA configurations for various plausible abnormal scenarios. The proposed method is based on multiscenario simulation and optimization, comprising two phases: (1) design of optimal DMA layout for each scenario using the pressure uniformity index to optimize the placement of flow meters and gate valves, and (2) dynamic transformation of the base DMA configuration into an adaptive DMA layout adapting to abnormal conditions and optimization of the locations and statuses of the control valves. Moreover, we used a real-world WDN to demonstrate the effectiveness of the proposed approach, and the obtained results revealed the efficiency and appropriate performance of the adaptive DMA layouts for sustainable adaptation of WDNs under anomalous conditions.