Showing papers on "Thermal mass flow meter published in 2014"

System for and method of monitoring flow through mass flow controllers in real time

Abstract: A mass flow controller comprises: a first flow meter constructed and arranged to measured flow rate of mass through the mass flow controller; a second flow meter constructed and arranged to measure flow rate of mass through the mass flow controller; a control valve constructed and arranged so as to control the flow rate of mass through the mass flow controller in response to a control signal generated as a function of the flow rate as measured by one of the flow meters; and a system controller constructed and arranged to generate the control signal, and to provide an indication when a difference between the flow rate of mass as measured by the first flow meter and the flow rate of mass as measured by the second flow meter exceeds a threshold.

A dynamic thermal flow sensor for simultaneous measurement of thermal conductivity and flow velocity of gases

Abstract: Through finite element modeling and experiments, we describe individual influences of gas flow velocity (v) and thermal conductivity (λ) on temperature amplitude and phase measurements from a dynamic MEMS thermal flow sensor that employs AC heating at 200 Hz. We further describe the relationships among the temperature phase, time-of-flight, and time-of-diffusion proposing a new boundary layer definition based on the existing flow and thermal boundary layer theories. The sensor has five primary thermistors made of amorphous germanium for high sensitivity. Four of these are symmetrically distributed around four central heater elements on a thermally isolating diaphragm where the fifth is in the center. Simulations and experimental results show that phase shifts (time lags) of temperature between thermistors primarily depend on λ, and negligibly on v below a velocity limit. Simulation results also suggest that the influences of density (ρ) and specific heat capacity (cP) on these phase shifts are relatively small or even negligible. Thus, λ can be accurately determined independent of the flow velocity for gases of similar ρ · cP product, up to 1 m/s under the set flow boundary conditions. Hence, simultaneous determination of thermal conductivity and flow velocity is expected to be feasible with this sensor under these circumstances, which, in turn, allows medium-independent flow sensing for a such selected set of gases. Experimental results show that the measurement resolution and maximum inaccuracy of λ within the prescribed flow conditions are approximately equal to 2.445% and 3.18 + 4.20% (nonlinearity + velocity dependence) of the actual thermal conductivity, respectively.

Nonintrusive performance measurement of a gas turbine engine in real time

Abstract: Performance of a gas turbine engine is monitored by computing a mass flow rate through the engine. Acoustic time-of-flight measurements are taken between acoustic transmitters and receivers in the flow path of the engine. The measurements are processed to determine average speeds of sound and gas flow velocities along those lines-of-sound. A volumetric flow rate in the flow path is computed using the gas flow velocities together with a representation of the flow path geometry. A gas density in the flow path is computed using the speeds of sound and a measured static pressure. The mass flow rate is calculated from the gas density and the volumetric flow rate.

CFD Aided Investigation of Multipath Ultrasonic Gas Flow Meter Performance Under Complex Flow Profile

Abstract: This paper presents a systematic investigation of the influence of complex flow profiles on the performance of multipath ultrasonic gas flow meter by using computational fluid dynamics (CFDs) simulation. To guarantee the overall agreement between the CFD predictions and the measurements, the meshing approaches, generation of boundary layers, turbulence models, and wall treatment methods for CFD simulation are elaborated carefully. The performances of a multipath ultrasonic gas flow meter under complex flow profiles, regarding to an out-plane double-elbow with a half-moon block and an out-plane double-elbow with a half-moon block equipped with a Spearman conditioner, are investigated. The simulation results demonstrate that for complex flows with strong asymmetric and swirling velocity profiles inside an out-plane double-elbow pipeline with a half-moon block, a four-path ultrasonic flow meter located at 20-D right after the second elbow together with a Spearman conditioner installed 16-D upstream the meter is of providing a flow velocity estimation that the error is within ±0.5%, while the Reynolds number ranges from 3.25×103 to 3.25×105. The effect of sound path orientation on the performance of flow meter is also discussed.

Integrated multi-parameter flow measurement system

Abstract: We have designed and realized an integrated multiparameter flow measurement system, consisting of an integrated Coriolis and thermal flow sensor, and a pressure sensor. The integrated system enables on-chip measurement, analysis and determination of flow and several physical properties of both gases and liquids. With the system, we demonstrated the feasibility to measure the flow rate, density, viscosity, specific heat capacity and thermal conductivity of hydrogen, helium, nitrogen, air, argon, water and IPA.

Ultrasonic flow metering with laminar to turbulent transition flow control

Abstract: Apparatus and method for ultrasonic flow metering of viscous fluids. In one embodiment, an ultrasonic flow metering system includes an ultrasonic flow meter, a flow conditioner, and a reducer. The ultrasonic flow meter includes a pair of ultrasonic transducers arranged to exchange ultrasonic signals through a fluid stream flowing between the transducers. The flow conditioner is disposed upstream of the ultrasonic flow meter. The reducer is disposed between the flow conditioner and the ultrasonic flow meter to reduce the cross sectional area of the fluid stream flowing from the flow conditioner to the ultrasonic flow meter.

System for and method of providing pressure insensitive self verifying mass flow controller

Abstract: A mass flow controller comprises: a pressure-based flow meter, a thermal-based flow meter, a control valve, and a system controller. The pressure-based flow meter and thermal-based flow meter each measure flow rate of mass through the mass flow controller. The control valve controls the flow rate in response to a control signal generated as a function of the flow rate as measured by thermal-based flow meter when the measured flow rate is relatively low, and as a function of the flow rate as measured by the pressure-based flow meter when the flow rate is relatively high. A comparison of the flow measurements of the two flow meters can be used to (a) sense pressure disturbances at low flow rates, and (b) sense when the thermal-based flow meter is out of calibration so that a zero offset signal can be applied to the thermal-based flow meter.

A Method for Gas Identification in Thermal Dispersion Mass Flow Meters

Abstract: A novel measurement method for identifying the type of gas in a thermal dispersion mass flow meter is presented. The physical background of the gas-identification method is discussed by employing a simple, one-dimensional, mathematical model of a thermal flow sensor. For a practical realization of the gas-identification method, the thermal dispersion mass flow meter has to contain two thermal flow sensors with different constructional or operational parameters. A thermal dispersion mass flow meter containing two thermal flow sensors with circular and square cross-sections was developed and calibrated for five different gases in order to experimentally validate the gas-identification method. If the measurement characteristics for the improper gas are employed, the mass flow readings of the thermal flow sensors will generally differ. The absolute value of the relative difference in the mass flow readings can be used as an objective function for identifying the type of gas from a defined set of gases with known compositions. In addition, the normalized error is proposed as an objective function to consider the dispersion that could be reasonably attributed to the difference in the mass flow readings.

Apparatus and method for wellhead testing

Abstract: A wellhead test system comprising: i) a Coriolis mass flow meter configured to receive a flow of a liquid; ii) a water analyzer configured to receive the flow of the liquid; and iii) a controller coupled to the Coriolis mass flow meter and the water analyzer. The controller receives from the Coriolis mass flow meter at least one of: mass flow measurement data, mass density measurement data, and drive gain and also receives from the water analyzer at least one of water frequency measurement data, oil frequency measurement data, and insertion loss measurement data. The controller determines a gas volume fraction (GVF) value and modifies the operation of the Coriolis mass flow meter and the water analyzer based on the GVF value.

Enhanced differential thermal mass flow meter assembly and methods for measuring a mass flow using said mass flow meter assembly

Abstract: A differential thermal mass flow meter assembly (1) for measuring a mass flow of a gas or liquid is disclosed, wherein it comprises: a flow channel (2), in which the gas or liquid is flowing, at least two heating elements (4, 4', 4'') arranged in the flow direction on the inside wall (3) of said flow channel (2), at least one thermal sensor (5) arranged in the flow direction up-stream said heating elements (4, 4', 4'') on the inside wall (3) of said flow channel (2), at least one thermal sensor (6'') arranged in the flow direction down-stream said heating elements (4, 4', 4'') on the inside wall (3) of said flow channel (2), as well as a method of measuring the mass flow of a gas or liquid using said differential thermal mass flow meter assembly.

A sensor for monitoring rheologically complex flows

Abstract: Flow sensors, systems, and methods for continuous in situ monitoring of a rheologically complex fluid flow within a vessel, such as particulate and multiphase media for ascertaining certain fluid flow parameters, such as flow rate, dynamic viscosity, fluid density, fluid temperature, particle density and particle mass, from flow sensor measurements. The system involves a fluid flow sensor having a body member with internalized strain gauges configured to measure the deformation of certain segments of the body member. Based, at least in part, on these deformation measurements, the system is used to compute the fluid flow parameters.

Thermal mass flow meter

Abstract: To provide a thermal mass flow meter that makes enhanced gas flow rate measurement accuracy possible while securing thermal mass flow meter reliability (while preventing degradation and damage resulting from droplet adhesion), a thermal mass flow meter according to the present invention is characterized by having a heat-generating element that generates heat by having electric current passed therethrough, a temperature detection bridge circuit that detects the temperature of the heat generating element, and a sensor element drive circuit unit that is connected to the heat generating element and the temperature detection bridge circuit and controls the passing of electric current through the heat generating element; in that the sensor element drive circuit unit has an output mechanism and an output impedance adjustment mechanism; and in that the output impedance adjustment mechanism is provided between the output mechanism and the heating-generating element and has an output impedance that is higher than the electrical resistance value of the heat-generating element and is less than 1 MΩ.

Cfd simulation on different geometries of venturimeter

Abstract: This paper describe an analytical approach for comparison of four different models to describe the velocity, pressure, turbulence and mass flow rate taken place in the venturimeter and graph are plotted. Venturimeter are most commonly used for flow meters for measuring volumetric or mass flow rate and velocity of fluid flowing through the venturimeter. Hence are also know as variable head meters. Variable head meters work on the principle that a variation of the flow rate through a constriction with a constant cross-sectional area causes a pressure drop suffered by the fluid as it flows through the constriction. The pressure drop is related to the flow rate, and hence variations of the pressure drop can be used to measure variations in the flow rate. Fluent soft ware was used to plot the characteristics of the flow of fluid through the flow meter and gambit software was used to design the 2D model. Two phase computational fluid dynamic calculation, using K-Epsilon model were employed. The numerical results were validated against experimental data from the literature and were found to be in good agreement. The pressure recovery is better in the venturi meter.

Magnetic inductive flow meter and method for operating a magnetic inductive flow meter

Abstract: The invention relates to a magnetic field generating device (1) associated with a magnetic inductive flow meter for generating an alternating magnetic field that extends at least also perpendicular to the longitudinal axis of a measuring tube (not illustrated). In the illustrated embodiment, the magnetic field generating device (1) comprises at least one field coil (2), a current regulator (3), a switching bridge (4), and a microcontroller (5). According to the invention, two different coil voltages are provided for the coil current supply, namely, an initial voltage and a lower operating voltage, and a voltage selector switch (6) for switching from the initial voltage to the operating voltage - and vice versa - is provided.

Thermal mass flow meter

Abstract: A thermal mass flow meter includes a housing, a control module, a plurality of probes, a flow calculation circuit, and a heating module. The control module is installed in a containing space. The probes are connected to one terminal of the housing. The flow calculation circuit is connected to the control module, and has a plurality of circuit boards installed in the probes and a plurality of temperature sensing units connected to the circuit boards. The heating module is connected on one of the circuit boards, and connected to the control module. The control module controls the heating module to heat a working fluid in a pipeline; the flow calculation circuit senses the temperature inside the pipeline to acquire temperature change values, and transmits the temperature change values to the control module; and the control module measures the fluid velocity of the working fluid.

Thermal flow meter, temperature measurement device, and thermal flow meter program

Abstract: In order to provide a thermal flow meter capable of correcting, more accurately than conventional thermal flow meters, zero error and span error that change according to environmental temperature, capable of easily calculating correction amounts used in correction, by using the same calculation formula and regardless of the type of fluid, and capable of reducing identification work, the thermal flow meter comprises: a flow path through which a fluid to be measured flows; an upstream-side electric resistance element provided on the upstream side of the flow path; a downstream-side electric resistance element provided on the downstream side of the flow path; and a flow rate calculation unit that calculates the flow rate for the fluid to be measured, on the basis of an upstream side voltage being voltage applied to the upstream-side electric resistance element, a downstream-side voltage being voltage applied to the downstream-side electric resistance element, and the thermal conductivity of the fluid to be measured.

Thermal mass flow meter

Abstract: To provide a thermal mass flow meter that makes enhanced gas flow rate measurement accuracy possible while securing thermal mass flow meter reliability (while preventing degradation and damage resulting from droplet adhesion), a thermal mass flow meter according to the present invention is characterized by having a heat-generating element that generates heat by having electric current passed therethrough, a temperature detection bridge circuit that detects the temperature of the heat generating element, and a sensor element drive circuit unit that is connected to the heat generating element and the temperature detection bridge circuit and controls the passing of electric current through the heat generating element; in that the sensor element drive circuit unit has an output mechanism and an output impedance adjustment mechanism; and in that the output impedance adjustment mechanism is provided between the output mechanism and the heating-generating element and has an output impedance that is higher than the electrical resistance value of the heat-generating element and is less than 1 M[Ohm]

Method for calibrating mass flow controllers in a printing apparatus for dispensing a liquid composition on a backplane

Abstract: A method for calibrating liquid flow measurements in a printing apparatus that includes a liquid flow line having a flow meter therein comprises the steps of: (a) using a positive displacement liquid pump operable while connected in fluid communication with the flow meter, pumping a liquid at a directly measured, precisely dispensed flow rate through the flow meter; (b) using the flow meter, measuring the volumetric flow rate of a liquid passed through the flow meter; (c) comparing the volumetric flow rate dispensable by the pump to a volumetric flow rate measurable by the flow meter; and (d) modifying the calibration parameters of the flow meter in accordance with the flow rate dispensed from the pump.

Flow sensor with improved linear output

Abstract: A flow sensor assembly includes a flow sensor for sensing a flow parameter. The flow sensor may provide a flow sensor output signal that is related to the sensed parameter. A control block operatively connected to the flow sensor may receive a measure related to the flow rate of the fluid stream and drive the heater of the flow sensor to a heater temperature, such that the heater temperature may be dependent on the flow rate of the fluid stream, which causes the analog output of the flow sensor to be relatively linear over an expected operating range of flow rates.

Device and method for multiphase flow meter calibration using a closed loop multiphase flow system

Abstract: Calibration of a multiphase flow meter to be used in a production process can be achieved by using a closed multiphase flow loop. In the device and method of the invention, the flow rates of each phase, oil and water, are individually measured after their separation using a separation vessel, and used as a reference for the calibration of a multiphase flow meter. Flow loop control is achieved by combining an oil-water interface position control and an oil level control in the separation vessel.

Swirl flow measurement sensor and swirl flow measurement meter for measuring the flow velocity of a fluid

Abstract: The invention relates to a swirl flow meter for measuring the flow velocity of a fluid flowing in a measurement pipe and to a swirl flow sensor for the swirl flow meter. The swirl flow sensor (1) has a main housing body (2) having a center axis (A). A shoulder (2a) having a contact surface (2c) is formed on a connecting section of the main housing body. A membrane (3) is arranged in a plane of the shoulder (2a), an edge of which is positioned over the contact surface (2c) and is axially spaced from the contact surface. The swirl flow sensor also has a flange-shaped supporting device (8), which has a radial edge segment (8c) and a cylindrical axial segment (8d), wherein the radial edge segment (8c) lies against the shoulder (2a) of the main body (2) by means of a surface (8e) of the radial edge segment and the cylindrical axial segment (8d) extends parallel to the center axis (A), such that the membrane (3) is supported against the supporting device (8) when a predetermined pressure is applied to the membrane.

Temperature control apparatus and test apparatus

Abstract: Increase in number of valves complicates the configuration and control. A temperature control apparatus for controlling a temperature of a device, includes; a heat exchange section exchanging heat with the device; a main flow path causing a fluid to flow; a sub flow path causing, to flow, a fluid having a temperature different from a temperature of the fluid flowing through the main flow path; a mixture flow path merging the fluids from the main flow path and the sub flow path and causing the merged fluids to flow to the heat exchange section; and a flow rate adjusting section adjusting an amount of a fluid flowing from the sub flow path to the mixture flow path, in relation to the fluid flowing through the main flow path.