Showing papers on "Thermal mass flow meter published in 2017"

Microparticle tracking velocimetry as a tool for microfluidic flow measurements

Abstract: The accurate measurement of flows in microfluidic channels is important for commercial and research applications. We compare the accuracy of flow measurement techniques over a wide range flows. Flow measurements made using holographic microparticle tracking velocimetry (µPTV) and a gravimetric flow standard over the range of 0.5–100 nL/s agree within 0.25%, well within the uncertainty of the two flow systems. Two commercial thermal flow sensors were used as the intermediaries (transfer standards) between the two flow measurement systems. The gravimetric flow standard was used to calibrate the thermal flow sensors by measuring the rate of change of the mass of liquid in a beaker on a micro-balance as it fills. The holographic µPTV flow measurements were made in a rectangular channel and the flow was seeded with 1 µm diameter polystyrene spheres. The volumetric flow was calculated using the Hagen–Pouiseille solution for a rectangular channel. The uncertainty of both flow measurement systems is given. For the gravimetric standard, relative uncertainty increased for decreasing flows due to surface tension forces between the pipette carrying the flow and the free surface of the liquid in the beaker. The uncertainty of the holographic µPTV measurements did not vary significantly over the measured flow range, and thus comparatively are especially useful at low flow velocities.

Measurement of the Flow Rate of Liquids and Gases by Means of Variable Pressure Drop Flow Meters with Flow Straighteners

Abstract: A model of the flow of liquid through measuring pipes that incorporate flow straighteners is proposed. A method of determining the flow rate of liquid by means of variable pressure drop flow meters is investigated. The parameters of flow straighteners that affect the process of measuring the flow rate of liquid are considered.

An implementation of ultrasonic water meter using dToF measurement

Abstract: A method of the ultrasonic transmission time difference (ToF) flow measurement is the one which is mainly applied to large diameter flow meters by incorporating high power digital signal processing...

The measurement of small flow

Abstract: The paper presents an electrochemical flow meter. It is based on a principle of measuring a response to chemical reaction which depends on the flow. The ferro/ferricyanide redox couple has reliable and robust electrochemical kinetics. The reaction consists of transfer of one electron and change of solvation structure without any change of complex structure. If the geometry of electrochemical cell is not changed the output current depends only on the flow through the cell. This device enables measurement of extremely low flows which is important in microsystem hydrodynamic studies. Measured flow limit of detection is 100 pl/min. The flow resolution is better than 1 pl/min. Time resolution of flow is better than 1 s. The device was used in study of peristaltic pump and movable piston pump flow. Sensitive measurement of flow and use of Fast Fourier Transform (FFT) has proved that noise generated by pump is periodic and correlates with the flow. The signal after pump pulsation elimination has white noise. The analysis of sensor signals with FFT in systems with peristaltic pumps or movable piston pumps enables to split the signal to periodic component correlating with the flow and non-periodic component correlating with the measured concentration.

Non-intrusive gas flow measurement using thermal signatures with online dynamic parameter estimation

Abstract: Fluid flow in pipes is a key component in many industrial systems, including process heating & cooling, building space conditioning, oil & gas production, and steam systems. When evaluating these systems for potential energy savings or health diagnostics, one of the critical measurements is the flow rate of the working fluid. Current methods for non-intrusive, non-invasive methods are expensive and often require time-consuming calibration. Research in the literature on potential low-cost flow rate measurement relies on knowledge of pipe parameters, pipe dimensions and fluid properties. This paper presents work on using dynamic parameter estimation using the gradient descent method with the thermal response of a pipe to measure flow. Using a constant heat flux and derived analytical model, the thermal conductivity, heat capacity, and internal flow rate are estimated online during data collection. Initial parameter estimates are dynamically determined to improve convergence by leveraging unique relationships in the thermal response. Simulation results show the potential of the method, along with preliminary experimental results from air flow in a steel pipe.

Numerical study of gas-liquid flow morphology in a vertical flowmeter nozzle

Abstract: Industrial multiphase flow measurement systems often contain meters based on Venturi principle. Those instruments deal with the differential pressure measurements whose accurate interpretation is possible when the flow morphology is known a-priori. The present paper reports the results of CFD-modelling of a gas-liquid flow through a vertical nozzle accompanied by a blind-T flow conditioner. The model is used for evaluation of the flow morphology in case the volume fractions of both phases are comparable. The model demonstrates high non-uniformities of the flow field after the blind-T, which indicates that this type of flow conditioners may lead to inaccurate results.

Thermal mass flow rate sensor, thermal mass flow rate sensor production method, and thermal mass flow meter using said thermal mass flow rate sensor

Abstract: For a thermal mass flow rate sensor 10 enclosed in a sealed container 11 having an inert atmosphere for the purpose of suppressing the loss of covering layers of sensor wires 13a, 13b associated with high-temperature use, an exhaust pipe 16 is further provided that causes the inner space of the sealed container 11 and the outside to be in airtight communication with each other via an exhaust hole 16a that is a through-hole formed in the outer wall of the sealed container 11. The end part on the opposite side of the exhaust pipe 16 from the exhaust hole 16a is sealed through plastic deformation so as to form a sealed part 16b. As a result, it is possible to airtightly close the internal space of a sealed container 11 after forming the sealed container 11 in a normal atmosphere. The sealed part 16b may be further sealed through welding. In this way, it is possible to assemble a sealed container 11 simply and with a high degree of accuracy and suppress reduction in the airtightness of the sealed container 11 associated with high-temperature use.

Mass flow measurement of two-phase carbon dioxide using coriolis flowmeters

Abstract: Carbon Capture and Storage (CCS) is considered as an important technology to reduce CO 2 emission from electrical power generation and other industrial processes. In the CCS chain, i.e. from capture to storage via transportation, it is essential to realize accurate measurement of CO 2 flows for the purpose of accounting and potential leakage detection. However, there are some significant challenges for the current flow metering technologies to achieve the specified 1.5% measurement uncertainty in the EU-ETS (European Union — Emissions Trading Scheme) for all expected flow conditions. Moreover, there are very few CO 2 flow test and calibration facilities that can recreate CCS conditions particularly two-phase CO 2 flow in pipelines together with accurate measurement standards. As one of the most potential flowmeters that may be used in the CCS chain, Coriolis flowmeters have the advantages of direct measurement of mass flow rate regardless of its state (liquid, gas, gas/liquid two-phase or supercritical) in addition to the measurement of temperature and density of CO 2 for the characterization of flow conditions. This paper assesses the performance of Coriolis flowmeters incorporating a soft-computing correction method for gas-liquid two-phase CO 2 flow measurement. The correction method includes a pre-trained backpropagation neural network. Experimental work was conducted on a purpose-built 25 mm bore two-phase CO 2 flow test rig for liquid mass flowrate between 300 kg/h and 3050 kg/h and gas mass flowrate from 0 to 330 kg/h under the fluid temperature of 19∼21 °C and pressure of 54∼58 bar. Experimental results suggest that the Coriolis flowmeters with the developed correction method are capable of providing the mass flow rate of gas-liquid CO 2 flow with errors mostly within ±2% and ±1.5% on horizontal and vertical pipelines, respectively.

Development of a computational tool to determine the flow regime in a rectangular hydraulic channel with experimental validation

Abstract: The hydraulic flow channels are open conduits at atmospheric pressure which flow along a free surface. The hydraulic channel is a flow in free conduit, subject to the atmospheric pressure and can be realized in two ways: permanent and uniform and not permanent. The hydraulic conditions of flow and flow are determined through a systematic set of calculations and mathematical operations that will define the variable characteristics involved in the system. The motivation of the study of this relevant topic can be increased with the use of mathematical software used in engineering. The aim of the research was to study a rectangular hydraulic flow channel with the use of a computational tool. In this work the development of the program was through the App Designer of Matlab. A Pitot tube was used to determine the average flow velocity as a method of experimental validation. These data were obtained from the use of an experimental unit equipment in the ESAMC Santos hydraulics laboratory. This channel allows to vary the flow through a scalar potentiometer and to change the slope with the aid of a hydraulic jack. The flow velocity data were obtained by calculation from the wet area and height of the water level of the channel. The software was developed to analyze the channel geometry, flow regimes and hydraulic conditions. The software also generated the mean velocity curves which enabled a more qualitative analysis of the flow profile. It has been shown that the velocity reduction towards the bed for the flows of 0.04855 to 0.001086 cubic meters per second and inclinations of 0 to 20 cm. The critical flow conditions indicate minimum values ​​of energy ranging from 0.063 to 0.027 meters, reaching a section of the channel of better hydraulic yield when the flow is adjusted for this condition. The software performed the simultaneous calculations that could determine the behavior of the flow regime for a range of flow and slope of the channel. Keywords Hydraulic channel. Matlab App Designer. Flow channel. Flow regime