Showing papers on "Thermal mass flow meter published in 2015"

Mass flow meter hardware

Abstract: Microprocessor-based thermal dispersion mass flow meters (i.e., thermal anemometers) are described that use temperature sensing elements in its flow sensor probe(s) in addition to the two elements commonly used. Such systems allow for automatically managing changes in gas selection, gas temperature, gas pressure, and outside temperature. One mass flow meter described has a flow sensor with four temperature sensing elements, wherein one pair is provided in a temperature sensor probe and another pair in a velocity sensor probe. Another variation operates without a separate temperature sensor probe and integrates all function into a single three-sensor probe. Such a device may also be used in conjunction with a one- or two-sensor temperature probe.

Measurement of oil-water flow via the correlation of turbine flow meter, gamma ray densitometry and drift-flux model

Abstract: The flow rate of the oil-water horizontal flow is measured by the combination of the turbine flow meter and the single-beam gamma ray densitometry. The emphasis is placed on the effects of the pipe diameter, the oil viscosity and the slip velocity on the measurement accuracy. It is shown that the mixture flow rate measured by the turbine flow meter can meet the application requirement in the water continuous pattern (o-w flow pattern). In addition, by introducing the developed drift-flux model into the measurement system, the relative errors of measurements for component phase flow rates can be controlled within +/- 5%. Although more accurate methods for the flow rate measurement are available, the method suggested in this work is advantageous over other methods due to its simplicity for practical applications in the petroleum industry.

Determining the gas permeability coefficient of a porous medium by means of the bubble-counting flow meter

Abstract: In this paper the conception of a low-cost device to determine the coefficient of permeability was presented. In the apparatus a non-typical source of gas and gas flow meter has been used. A used flow meter allows us to measure very low gas flow rates. The upper measurement range limit of the constructed device was about 20 cm3 min−1, whereas the lower measurement range limit was estimated to be approximately 0.01 cm3 min−1.

Thermal mass-flow meter and mass-flow control device using same

Abstract: A thermal mass-flow meter and mass-flow controller using the mass-flow meter are disclosed. The mass flow meter includes a base having an installation surface, a passage for fluid, and a bypass in the middle of the passage. The mass-flow meter also includes a case in contact with the installation surface of the base and housing a sensor tube and sensor wires. The mass flow sensor also includes a sensor circuit including a bridge circuit including the sensor wires and other resistive elements. A heat-transfer block is positioned adjacent to the case and in contact with the installation surface of the base. A bottom surface of the heat-transfer block and the installation surface of the base are in surface contact with each other, and at least one lateral surface of said heat-transfer block and a lateral surface of said case are in surface contact with each other.

Effect of gas temperature on flow rate characteristics of an averaging pitot tube type flow meter

Abstract: The flow rate characteristics passing through an averaging Pitot tube (APT) while constantly controlling the flow temperature were studied through experiments and CFD simulations. At controlled temperatures of 25, 50, 75, and 100°C, the flow characteristics, in this case the upstream, downstream and static pressure at the APT flow meter probe, were measured as the flow rate was increased. The flow rate through the APT flow meter was represented using the H-parameter (hydraulic height) obtained by a combination of the differential pressure and the air density measured at the APT flow meter probe. Four types of H-parameters were defined depending on the specific combination. The flow rate and the upstream, downstream and static pressures measured at the APT flow meter while changing the H-parameters were simulated by means of CFD. The flow rate curves showed different features depending on which type of H-parameter was used. When using the constant air density value in a standard state to calculate the H-parameters, the flow rate increased linearly with the H-parameter and the slope of the flow rate curve according to the H-parameter increased as the controlled target air temperature was increased. When using different air density levels corresponding to each target air temperature to calculate the H-parameter, the slope of the flow rate curve according to the H-parameter was constant and the flow rate curve could be represented by a single line. The CFD simulation results were in good agreement with the experimental results. The CFD simulations were performed while increasing the air temperature to 1200 K. The CFD simulation results for high air temperatures were similar to those at the low temperature ranging from 25 to 100°C.

Coriolis flow meter having flow tube with equalized pressure differential

Abstract: A Coriolis flow meter for a drilling system measures flow from a wellbore and/or from at least one pump into the wellbore. The meter can be disposed upstream of at least one choke used for controlling backpressure, and/or the meter can be disposed between at least one pump and the wellbore. The meter has at least one flow tube adapted to vibrate and conducts the flow at a first pressure level from an inlet side to an outlet side. A vessel encloses the at least one flow tube at least between the inlet and outlet sides and holds a second pressure level therein about the at least one flow tube. The second pressure level can be equal to or nearly equal to the first pressure level to reduce or nearly eliminate a pressure differential across the at least one flow tube. For example, the second pressure level can be elevated above environmental relative to the first pressure level to reduce a pressure differential across the at least one flow tube. Alternatively, the second pressure level can be less than the first pressure level.

Development of a flow rate monitoring method for the wearable ventricular assist device driver

Abstract: Our research institute has been working on the development of a compact wearable drive unit for an extracorporeal ventricular assist device (VAD) with a pneumatically driven pump. A method for checking the pump blood flow on the side of the drive unit without modifying the existing blood pump and impairing the portability of it will be useful. In this study, to calculate the pump flow rate indirectly from measuring the flow rate of the driving air of the VAD air chamber, we conducted experiments using a mock circuit to investigate the correlation between the air flow rate and the pump flow rate as well as its accuracy and error factors. The pump flow rate was measured using an ultrasonic flow meter at the inflow and outflow tube, and the air flow was measured using a thermal mass flow meter at the driveline. Similarity in the instantaneous waveform was confirmed between the air flow rate in the driveline and the pump flow rate. Some limitations of this technique were indicated by consideration of the error factors. A significant correlation was found between the average pump flow rate in the ejecting direction and the average air flow rate in the ejecting direction (R2 = 0.704-0.856), and the air flow rate in the filling direction (R2 = 0.947-0.971). It was demonstrated that the average pump flow rate was estimated exactly in a wide range of drive conditions using the air flow of the filling phase.

Proportional Control Valves Integrated in Silicon Nitride Surface Channel Technology

Abstract: We have designed and realized two types of proportional microcontrol valves in a silicon nitride surface channel technology process. This enables on-die integration of flow controllers with other surface channel devices, such as pressure sensors or thermal or Coriolis-based (mass) flow sensors, to obtain a proportional gas flow control system on a single chip. One valve design is implemented with inlet and outlet channels in the plane of the chip, which allows on-chip flow control between several fluidic components and allows up to 70 mgh $^{-1}$ of flow at 200 mbar. The other valve design operates out-of-plane between surface channels and a fluidic inlet, offering a flow range up to 1250 mgh $^{-1}$ at 600 mbar, smaller footprint, and low-leakage closure. Measured flow behavior agrees well with laminar flow models created for both valve types. [2015-0060]

Effects of flow measurement on sloped pipes using ultrasonic flowmeter

Abstract: Precision in flow measurement has economic consequences and also necessitates fulfillment of stipulated requirement of straight length upstream and downstream of flow meter However, many times, the site constraints do not permit to fulfill this requirement IEC 41(1991) recommends use of ultrasonic flow meter as a complimentary to other flow measuring techniques for hydro turbines The motivation of the study is drawn from the typical water conductor system of hydro plants where the penstocks are generally sloped conduit in nature The experimental investigation presented in this paper is to highlight and simulate the variation in accuracy for flow rate measurement for Reynolds number ranging from 08 ×105 to 10 ×105 with clamp-on ultrasonic flow meter with different sloped straight length considering upstream and downstream length as per the standards The error in flow measurement by ultrasonic flow meter in straight length varied from −10% to +10% to the reference flow as per the acceptable level Whereas, the increase of slope straight angle the percentage of shift in error is increases The error in flow measurement of 6° degree pipe line was in the range of 40% Similarly, the conduit of 12° degrees pipe line was up to 8% The velocity distortion of the sloped pipes is also validated using commercial CFD Fluent solver These findings are useful in selecting suitable location for the installation Presently ultrasonic flow meters do not address the use at site conditions like sloped pipes Therefore the existing ultrasonic flow metering techniques need attention for up gradation

Characteristics of Flow Meters with Sediment Laden Flow - A Review

Abstract: Measurement of flow is an important aspect in the field of hydraulic engineering, both in case of open channel as well as pipe or conduits. In case of pipe conduits various flow meters are used for flow estimation; out of which venturimeter and orifice meter are most commonly used and conventional means. Pipes or conduit carrying sediment laden flow or slurry-water mixture is very common in most of the industries, sewage carrying system etc. Suitability of flow meters i.e. venturimeter and flow meter need to be analyzed for sediment laden flow. Due to the presence of slurry or sediments, coefficient of discharge of flow meter will vary. In the present paper, various works that have been carried out till now in the analysis of characteristics of venturimeter and orifice meter with sediment laden flow are described.

Method for calibrating flow meters for fluid media

Abstract: A method for calibrating flow meters for fluid media comprises the steps of guiding a medium (102) through a reference measuring section (101-1) and a test measuring section (101-2) which has a flow meter to be calibrated, establishing at least approximately identical and constant pressure and flow conditions for the medium (102) in both measuring sections (101-1, 101-2), detecting a reference throughflow of the medium (102) through the reference measuring section (101-1) and throughflow values which correspond temporally thereto and are measured by the flow meter (125) to be calibrated of the test measuring section at a preset medium temperature, comparing the detected reference throughflow through the reference measuring section (101-1) with the throughflow values which correspond temporally thereto of the flow meter (125) to be calibrated, in order, based on this, to determine at least one correction value for the calibration of the flow meter (125) at the preset medium temperature, and determining of the respective correction value for the flow meter (125) for different medium temperatures of the medium (102), in order to determine a calibrating function using the temperature-dependent correction values as grid points.

Gaseous fuel control device for engines

Abstract: A fuel control device or fuel valve assembly includes a valve for metering flow of gaseous fuel to an engine, a drive device associated with the valve to adjust the effective flow area of the valve, a flow meter with at least one fixed area orifice located upstream of the valve, and one or more sensors to measure predetermined parameters of the fuel flowing through the flow meter. A controller receives input from the flow sensor or sensors and a fuel demand signal from the engine control, calculates current flow rate based on the sensor inputs, and controls the drive device to adjust the valve flow area up or down depending on the difference between the calculated flow rate and current fuel demand signal.

Thermal mass flow rate measurement method, thermal mass flow meter using said method, and thermal mass flow controller using said thermal mass flow meter

Abstract: By supplying a pulse signal to sensor wires to make the sensor wires generate heat, instead of applying DC electric voltage to the sensor wires, an amount of energy supplied to the sensor wires is decreased while maintaining a signal intensity supplied to the sensor wires, or the signal intensity supplied to the sensor wires is increased while maintaining the amount of energy supplied to the sensor wires Thereby, a method for measuring a mass flow rate by a thermal type mass flow meter, which can reduce heat generation from the sensor wires while suppressing decrease in measurement accuracy, or can improve measurement accuracy while suppressing increase in heat generation from the sensor wires, is provided

Determination of fluid composition in a mass flow controller

Abstract: A method for determining a fluid composition parameter, e.g., a fluid identifier, a mixing ratio or a parameter describing heat transfer properties, of an unknown fluid in a mass flow controller is disclosed. A control valve of the mass flow controller is set so as to establish a constant flow, preferably zero flow, through the mass flow controller. A heating element of the flow sensor is heated, and at least one temperature value is measured with temperature sensors arranged on both sides of the heater while the fluid contacts the flow sensor. First calibration data (LUT1) are retrieved. The first calibration data have, as input values, temperature values measured with the flow sensor at the previously established constant flow and have, as output values, values of the fluid composition parameter. The first calibration data are used to determine the fluid composition parameter from the measured temperature value.

Mass flow meter configured with computational modeling for use with different fluids

Abstract: Microprocessor-based thermal dispersion mass flow meters (i.e., thermal anemometers) are described that use temperature sensing elements in its flow sensor probe(s) in addition to the two elements commonly used. Such systems allow for automatically managing changes in gas selection, gas temperature, gas pressure, and outside temperature. One mass flow meter described has a flow sensor with four temperature sensing elements, wherein one pair is provided in a temperature sensor probe and another pair in a velocity sensor probe. Another variation operates without a separate temperature sensor probe and integrates all function into a single three-sensor probe. Such a device may also be used in conjunction with a one- or two-sensor temperature probe.

A beam-membrane structure micromachined differential pressure flow sensor.

Abstract: A beam-membrane structure micromachined flow sensor is designed, depending on the principle of differential pressure caused by the mass flow, which is directly proportional to the square flow rate. The FSI (fluid structure interaction) characteristics of the differential pressure flow sensor are investigated via numerical analysis and analog simulation. The working mechanism of the flow sensor is analyzed depending on the FSI results. Then, the flow sensor is fabricated and calibrated. The calibration results show that the beam-membrane structure differential pressure flow sensor achieves ideal static characteristics and works well in the practical applications.

Distributed thermal flow metering

Abstract: A distributed flow metering system using a heating component and a temperature measuring system is disclosed. The rate of temperature change in the cable is related to a flow rate through the wellbore. The system includes a combination fiber optic and heating element cable configured to measure flow using temperature and without a direct flow measuring component.

Mass flow meter with self-diagnostic function and mass flow controller using the same

Abstract: In a mass flow meter comprising two flow sensor units with identical specifications, flow rate deviations between these two flow sensor units are initially measured at various mass flow rates under a circumstance having the same fluctuating factors as those when a mass flow is actually measured. Subsequently, based on these flow rate deviations, a correction value for matching the values of the mass flow rates measured by these two flow sensor units is calculated and stored in a data storage device. Thereafter, when measuring a mass flow rate, a flow rate deviation, from which the influence by the individual difference in the response to a fluctuating factor between these two flow sensor units has been removed, is calculated by correcting a measured value based on the correction value. The existence or non-existence of an occurrence of a malfunction is judged based on whether the flow rate deviation exceeds a predetermined threshold value t or not.

Mass flow rate measurement method, thermal mass flow meter using said method, and thermal mass flow controller using said thermal mass flow meter

Abstract: In a capillary heating type thermal type mass flow meter comprising a sensor configured to detect temperature and pressure of a fluid and a correction means configured to correct a mass flow rate based on said temperature and said pressure, change rates of the mass flow rate of the fluid with respect to temperature and pressure have been previously acquired, and the mass flow rate is corrected based on said temperature and said pressure as well as these change rates. Thereby, the mass flow rate can be measured accurately and simply even when the temperature and/or pressure of the fluid, whose mass flow rate is to be measured, change.

Meters and Valves

Abstract: In this chapter, we discuss the more commonly used devices for the measurement of liquid pipeline flow rates. The variable head flow meters, such as the venturi tube, flow nozzle, orifice meter, and the equations for calculating the velocities and flow rate from the pressure drop, are explained. The importance of the discharge coefficient and how it varies with the Reynolds number and the beta ratio are also discussed. A trial-and-error method for calculating the flow rate through an orifice meter is illustrated using an example. In the gas pipeline section, we cover the topics of valves and flow measurement as it relates to gas pipeline transportation. The various types of valves used and their functions are reviewed. The importance of flow measurement in natural gas pipeline transaction is explained. The predominantly used measuring device known as orifice meter is discussed in detail. The calculation methodology based on American Gas Association Report No. 3 is reviewed. The venturi meter and the flow nozzle are also discussed.