Showing papers on "Thermal mass flow meter published in 2013"

Uncertainty analysis for a virtual flow meter using an air-handling unit chilled water valve

Abstract: A virtual water flow meter is developed that uses the chilled water control valve on an air-handling unit as a measurement device. The flow rate of water through the valve is calculated using the differential pressure (DP) across the valve and its associated coil, the valve command, and an empirically determined valve characteristic curve. Thus, the uncertainty in the measurements could be significantly greater than for conventional hardware flow meters. In this article, mathematical models are developed and used to conduct uncertainty analyses for the virtual flow meter, and the results from the virtual meter are compared to measurements made with an ultrasonic flow meter. Theoretical uncertainty analysis shows that the total uncertainty in flow rates from the virtual flow meter is 1.46% with 95% confidence; comparison of virtual flow meter results with measurements from an ultrasonic flow meter yielded an uncertainty of 1.46% with 99% confidence. The comparable results from the theoretical uncertainty a...

Compact Mass Flow Meter based on a Micro Coriolis Flow Sensor

Abstract: In this paper we demonstrate a compact ready-to-use micro Coriolis mass flow meter. The full scale flow is 1 g/h (for water at a pressure drop < 1 bar). It has a zero stability of 2 mg/h and an accuracy of 0.5% reading for both liquids and gases. The temperature drift between 10 and 50 °C is below 1 mg/h/°C. The meter is robust, has standard fluidic connections and can be read out by means of a PC or laptop via USB. Its performance was tested for several common gases (hydrogen, helium, nitrogen, argon and air) and liquids (water and isopropanol). As in all Coriolis mass flow meters, the meter is also able to measure the actual density of the medium flowing through the tube. The sensitivity of the measured density is ~1 Hz.m3/kg.

Thermal efficiency analysis of a single-flow solar air heater with different mass flow rates in a smooth plate

Abstract: This paper presents an experimental thermal efficiency analysis for a novel flat plate solar air heater with several mass flow rates. The aims are to review of designed and analyzed a thermal efficiency of flat-plate solar air heaters. The measured parameters were the inlet and outlet temperatures, the absorbing plate temperatures, the ambient temperature, and the solar radiation. Further, the measurements were performed at different values of mass flow rate of air in flow channel duct. After the analysis of the results, the optimal value of efficiency is higher level of mass flow rate equal to 0.0202 kg/s in flow channel duct for all operating conditions and the single-flow collector supplied with maximum mass flow rate appears significantly better than that another flow rate. At the end of this study, the thermal efficiency relations are delivered for different mass flow rates. Maximum efficiency obtained for the single pass air heater between the air mass flow rates from 0.0108 to 0.0184 kg/s; were 39.72% and 50.47 % respectively, with tilt angle equal 45° in location Biskra city of Algeria. The thermal efficiency correspondently the mass flow rates were 28.63, 39.69, 46.98, 55.70 and 63.61 %, respectively.

Multiphase flow metering system

Abstract: A multi-phase flow metering system for measuring a multi-phase fluid including oil, water, and gas, includes a Coriolis mass flow meter adapted to measure mass flow rate and density of the multi-phase fluid. The system has a water cut meter adapted to measure the water cut of the multi-phase fluid. A processor is configured to determine the oil mass flow rate of the oil, water mass flow rate of the water, and gas mass flow rate of the gas using the mass flow rate and density from the Coriolis meter and the water cut from the water cut meter. The processor is further configured to determine dynamic estimates of the uncertainty of each of the oil mass flow rate, water mass flow rate, and gas mass flow rate.

Non-invasive Thermal Dispersion Flow Meter with Chronometric Monitor for Fluid Leak Detection and Freeze Burst Prevention

Abstract: A non-invasive thermal dispersion flow meter with chronometric monitor for fluid leak detection includes a heater, an ambient temperature sensor and a flow rate sensor which are configured to sense the temperature of a fluid in a conduit, and then monitor the flow of that fluid through the conduit. The fluid flow sensor is incorporated into a Wheatstone bridge circuit which is used to provide increased sensitivity to the outputs of the sensors. Based upon the ambient temperature sensor readings, the flow rate sensor and heater may be adjusted to optimize the operation of the system to detect leaks. An alternative embodiment utilizes a single sensor and separate heater which work together to determine heat propagation times which in turn is used to calculate flow rate. Based on the sensor readings, the flow may be adjusted to prevent damage and leaks by relieving the system of excess pressure.

Ultrasonic flow metering using compensated computed temperature

Abstract: Apparatus and methods for verifying temperature measurements in an ultrasonic flow meter. An ultrasonic flow metering system includes a passage for fluid flow, a temperature sensor, an ultrasonic flow meter, and a flow processor. The temperature sensor is disposed to provide measured temperature of fluid flowing in the passage. The ultrasonic flow meter is configured to measure transit time of an ultrasonic signal through the fluid. The flow processor is configured to 1) compute speed of sound through the fluid based on the transit time; 2) calculate a computed temperature of the fluid based on the speed of sound; 3) apply compensation, based on a historical difference between the computed temperature and the measured temperature, to a temperature verification parameter; and 4) determine, based on the temperature verification parameter, whether a current difference between the measured temperature and the computed temperature is within a predetermined range.

Experimental and numerical design of a long-waist cone flow meter

Abstract: A long-waist cone flow meter is designed for steady differential pressure measurement and relatively small overall pressure drop. A constant-diameter annular flow channel is formed between cone element and pipe wall. The flow field of water flows through cone element is studied with 3-D CFD simulations. The constant-diameter annular channel is found being able to adjust the incoming fluid, and small rear angle of cone element could reduce flow separation and overall pressure difference. An optimized structure of long-waist cone flow meters, referred as LWC, is proposed based on the investigations on flow field analysis. A steady contracting differential pressure and an overall differential pressure can be tapped from a LWC. A set of LWCs was fabricated with diameter ratio β ranging from 0.55 to 0.75, and waist length L from 20 to 60 mm when β = 0.65 for experimental tests and CFD verifications. A decreasing trend of dimensionless differential pressure Δp* and δp* and an increasing trend of discharge coefficient Cd of LWCs under different Reynolds number are observed and analyzed, and flow rate prediction of different Newtonian single phase flow is experimentally studied. A case study of oil–water two-phase flow is then presented with a selected LWC and an average error below 5% is achieved when treating the mixture a homogeneous flow.

Optimal Micro-Vane Flow Control for Compact Air Vehicle Inlets

Abstract: The purpose of this study on micro-vane secondary flow control is to demonstrate the viability and economy of Response Surface Methodology (RSM) to optimally design micro-vane secondary flow control arrays, and to establish that the aeromechanical effects of engine face distortion can also be included in the design and optimization process These statistical design concepts were used to investigate the design characteristics of "low unit strength" micro-effector arrays "Low unit strength" micro-effectors are micro-vanes set at very low angles-of-incidence with very long chord lengths They were designed to influence the near wall inlet flow over an extended streamwise distance, and their advantage lies in low total pressure loss and high effectiveness in managing engine face distortion Therefore, this report examines optimal micro-vane secondary flow control array designs for compact inlets through a Response Surface Methodology

Three-Dimensional Flexible Thermal Sensor for Intravascular Flow Monitoring

Abstract: A novel design and assembly technology is developed for a three-dimensional (3-D) flexible thermal flow sensor based on convective heat transfer to reduce detection error caused by position variation of a sensor inside the flow of narrow and curved geometries, such as coronary artery. The 3-D sensor has three independent sensing elements equally distributed around the catheter tube. This arrangement introduces three independent information channels, and cross-comparisons are used to provide accurate flow measurement. The resistance of the sensing elements is measured at ~ 1-1.2 kΩ with the temperature coefficient of resistance at 0.086%/°C. Using a constant-current circuit, the three sensing elements are heated to ~ 10°C above ambient temperature. Flow testing is implemented in a pipe channel at two positions: on the wall and along the center line. Experimental results from these two positions are discussed and computational fluid dynamic simulation based on Newtonian fluid properties is implemented, showing comparable results within an acceptable range of experimental to simulation errors. Therefore, we demonstrate the capability of 3-D thermal flow sensor for detecting the position of the catheter in the flow channel, thereby providing an accurate flow measurement.

Reynolds number based verification for ultrasonic flow metering systems

Abstract: Apparatus and methods for monitoring operation of an ultrasonic flow meter. In one embodiment, an ultrasonic flow metering system includes a passage for fluid flow, an ultrasonic flow meter, and a condition monitor. The ultrasonic flow meter is configured to measure transit time of an ultrasonic signal through the fluid flowing in the passage. The condition monitor is coupled to the ultrasonic flow meter and is configured to monitor a parameter of ultrasonic meter operation with respect to Reynolds number. The condition monitor is further configured to determine whether a value of the parameter at a Reynolds number of the fluid flowing in the passage at a time associated with the value is within a predetermined range of values for the parameter at the Reynolds number.

Pressure type flow control system with flow monitoring, and method for detecting anomaly in fluid supply system and handling method at abnormal monitoring flow rate using the same

Abstract: A pressure type flow control system with flow monitoring includes an inlet, a control valve including a pressure flow control unit connected downstream of the inlet, a thermal flow sensor connected downstream of the control valve, an orifice installed on a fluid passage communicatively connected downstream of the thermal flow sensor, a temperature sensor provided near the fluid passage between the control valve and orifice, a pressure sensor provided for the fluid passage between the control valve and orifice, an outlet communicatively connected to the orifice, and a control unit including a pressure type flow rate arithmetic and control unit receiving a pressure signal from the pressure sensor and a temperature signal from the temperature sensor, and a flow sensor control unit to which a flow rate signal from the thermal flow sensor is input.

Viscometer for newtonian and non-newtonian fluids

Abstract: A viscometer comprises a plurality of capillary tubes connected in series with a mass flow meter. The capillary tubes are smooth, straight, and unimpeded, and each has a different known, constant diameter. Differential pressure transducers sense differential pressure across measurement lengths of each capillary tube, and the mass flow meter senses fluid mass flow rate and fluid density. A data processor connected to the mass flow meter and the differential pressure transducers computes viscosity parameters of fluid flowing through the viscometer using non-Newtonian fluid models, based on the known, constant diameters and measurement lengths of each capillary tube, the sensed differential pressures across each measurement length, the fluid mass flow rate, and the fluid density.

Ultrasonic flowmeter having pressure balancing system for high pressure operation

Abstract: A system is provided with an ultrasonic flow meter. The ultrasonic flow meter includes a first ultrasonic transducer disposed about a fluid flow path, and a pressure balancing system configured to pressure balance the first ultrasonic transducer relative to a fluid flow along the fluid flow path.

Non-invasive thermal dispersion flow meter with fluid leak detection and alert

Abstract: A non-invasive thermal dispersion flow meter with chronometric monitor for fluid leak detection includes a heater, an ambient temperature sensor and a flow rate sensor which are configured to sense the temperature of a fluid in a conduit, and then monitor the flow of that fluid through the conduit. The fluid flow sensor is incorporated into a Wheatstone bridge circuit which is used to provide increased sensitivity to the outputs of the sensors. Based upon the ambient temperature sensor readings, the flow rate sensor and heater may be adjusted to optimize the operation of the system to detect leaks. An alternative embodiment utilizes a single sensor and separate heater which work together to determine heat propagation times which in turn is used to calculate flow rate. Based on the sensor readings, the flow may be adjusted to prevent damage and leaks by relieving the system of excess pressure.

Experimental and Numerical Study on the Thermal Performance of a Water/Steam Cavity Receiver

Abstract: An experimental platform was designed and built for testing the thermal performance of a water/steam cavity receiver. The experimental platform was utilized to investigate the start-up performance and operation characteristics of the receiver. The electrical heating mode was chosen to simulate the non-uniform distribution of heat flux on the surface of absorber tubes inside the cavity. During start-up the temperature rise rate and the mass flow rate are considered as control variables. A couple of start-up curves under different working pressures were finally obtained. The results showed that the receiver performed at relatively low thermal efficiencies. The main reason for the low thermal efficiency was attributed to the low steam mass flow rate, which causes a high proportional heat loss. In order to study the relationship between thermal efficiency and mass flow rate, a computational model for evaluating the thermal performance of a cavity receiver was built and verified. This model couples three aspects of heat transfer: the radiative heat transfer inside the receiver, the flow boiling heat transfer inside the absorber tubes and the convection heat transfer around the receiver. The water/steam cavity receiver of the experimental platform was studied numerically. The curve of thermal efficiency versus mass flow rate was obtained to show that the thermal efficiency increases with increasing mass flow rate within a certain range, and the increase is more remarkable at low mass flow rates. The purpose of the present study was to determine an appropriate mass flow rate for the receiver of the experimental platform to ensure its efficient operation.

Ultrasonic flow metering system with an upstream pressure transducer

Abstract: Apparatus and method for monitoring operation of a flow metering system. In one embodiment, a flow metering system includes a flow meter, a first and second pressure sensors, a flow conditioner, and a condition monitor. The flow meter is configured to measure the volume of fluid flowing through the flow meter. The first pressure sensor is disposed proximate the flow meter to measure pressure of the fluid proximate the flow meter. The flow conditioner is disposed upstream of the flow meter. The second pressure sensor is disposed upstream of the flow conditioner to measure pressure of the fluid upstream of the flow conditioner. The condition monitor is coupled to the flow meter and the pressure sensors, and is configured to identify a potential discrepancy in operation of the flow metering system based on a difference between pressure measurements of the first and second pressure sensors.

Fuel supply system, fuel cell system, and method for running each

Abstract: The present invention enables the supply of an appropriate amount of gaseous fuel even if the composition of the gaseous fuel changes. A composition-independent flow rate meter (4) that can measure flow rate independently from the composition of gaseous fuel is disposed in series with a thermal flow rate meter (4) in the supply pathway of gaseous fuel. When the value measured by the thermal flow rate meter (3) and the value measured by the composition-independent flow rate meter (4) diverge by at least a certain amount, it is determined that there is an abnormal state, and a conversion factor with respect to the value measured by the thermal flow rate meter (3) is set. On the basis of the set conversion factor, the composition of the gaseous fuel is inferred, and on the basis of the inferred composition the target supply amount of gaseous fuel is corrected and controlled.

Effects of network pressure on water meter under-registration: an experimental analysis

Abstract: . In water supply systems, a considerable amount of apparent loss is caused by meter under-registration. Water meters are subject to intrinsic systemic error depending on the actual flow rates passing through them. Furthermore, the moving parts of the meter are subject to wear and tear that progressively reduce meter accuracy. The increase in systemic error is especially evident at low flow rates because of growing friction in the rotating mechanism, which requires a higher flow to start the meter (starting flow). The aim of this paper is to experimentally investigate metering error in an attempt to find a direct link between meter age, network pressure and apparent losses caused by the inability of the meter to accurately register the volume passing though it at low flow rates. The study was performed through laboratory experiments in which worn-out water meters were tested using a test bench. The results of the laboratory experiments show that ageing and pressure are both relevant parameters for determining meter starting flow. These results were then applied to assess the effects on apparent losses of the age of the meter, varying pressure values upstream of the meter (the pressure in the network where the meter is installed) and different patterns of flow rates passing through the device (the consumption pattern of the user). The presented results are useful for understanding the effects of operating conditions on water meter under-registration, which can aid water managers in implementing effective replacement campaigns.

System and method for using a rate of decay measurement for real time measurement and correction of zero offset and zero drift of a mass flow controller or mass flow meter

Abstract: The disclosed embodiments include a method, apparatus, and computer program product for providing a self-validating mass flow controller or mass flow meter. For example, in one embodiment, a self-validating mass flow controller is disclosed that does not require any software modification to a tool/tool controller in which the mass flow controller is being utilized. In other embodiments, a self-validating mass flow controller is disclosed that does not require any hardware or mechanical changes to an existing mass flow controller. Still, the disclosed embodiments further include a self-validating mass flow controller that is configured to determine valve leak and sensor offset simultaneously for performing real time in-situ correction of a mass flow controller's output for zero offset or zero drift in the presence of valve leak.

System and method for reducing flow perturbations and improving the accuracy of a rate of decay measurement in a mass flow controller

Abstract: A mass flow controller includes a fluid inlet, a fluid outlet, and a conduit defining a flow path along which the fluid flows through the mass flow controller. The mass flow controller includes an inlet block having an inlet aperture, an inlet channel fluidly coupled to the conduit, and one or more restrictors positioned along the flow path between the inlet aperture and inlet channel to minimize flow perturbations when a rate of decay measurement is taken or when flow the amount of pressure supplied to the valve inlet is otherwise interrupted.

System and method for improving the accuracy of a rate of decay (rod) measurement in a mass flow controller

Abstract: A mass flow controller includes at least one conduit having a fluid inlet and a fluid outlet, the conduit defining a flow path along which the fluid flows. The mass flow controller also includes a modified inlet block having an inlet aperture, an inlet channel, and a reservoir fluidly coupled to the inlet channel and the conduit that enhances flow through the controller and improves rate-of-decay measurements. The mass flow controller includes at least one flow sensor that generates a flow sensor signal that is proportional to the mass flow rate of the fluid through the conduit. The mass flow controller includes a control subsystem coupled to a flow sensor and a valve assembly to control flow through the conduit.

Flow meter with two temperature sensors in housing

Abstract: The present invention discloses a flow meter (1), such as a water meter, with integrated temperature reading of the supplied liquid. The flow meter comprises at least two temperature sensors arranged in a cavity (4) of the meter. A first temperature sensor (8) is arranged to measure a temperature of the cavity wall area, and a second temperature sensor (9) is arranged to measure an ambient temperature of the cavity. In this manner a flow meter is provided which is capable of measuring the temperature of the flowing liquid without penetrating the flow tube or the cavity.

Fluid meter device

Abstract: A gas meter device of the present invention comprises plural measurement fluid passages provided in parallel between an inlet into which a fluid flows, and an outlet from which the fluid flows out; flow value measuring sections provided in the measurement fluid passages, respectively, and configured to obtain flow values of fluids flowing through the measurement fluid passages, respectively; memories configured to store coefficient data which are values corresponding to the measurement fluid passages, respectively and indicating a relation between the flow values of the fluids flowing through the measurement fluid passages, respectively, and a total flow value of the fluid flowing from the inlet to the outlet; and total flow value estimation sections configured to estimate total flow values of the fluids based on the flow values obtained by the flow value measuring sections, respectively, and the coefficient data stored in the memories. This makes it possible to reduce time required for adjustment work in manufacturing steps of the fluid meter device assembled by connecting the plural measurement fluid passages in parallel.

Micro flow sensor

Abstract: A micro flow sensor includes: a flow path through which a fluid to be measured flows; a detection unit having a heater configured to heat the fluid to be measured in the flow path and temperature sensors configured to measure temperature of a fluid to be measured in the flow path; an arithmetic unit configured to measure a flow rate of the fluid to be measured flowing through the flow path based on the temperature of the fluid to be measured, measured by the temperature sensors; and a narrowed portion disposed on an upstream side of the detection unit in the flow path for narrowing the flow path.

Thermal, flow measuring apparatus and method for determining and/or monitoring flow of a medium

Abstract: A thermal, flow measuring apparatus for determining and/or monitoring flow of a measured medium through a measuring tube, comprising at least two temperature sensors, wherein a first temperature sensor is heatable, and a second temperature sensor serves to provide the temperature of the measured medium. According to the invention, the thermal, flow measuring apparatus has at least one measuring transducer for ascertaining the following properties of the medium: thermal conductivity, heat capacity, density and dynamic viscosity or thermal conductivity, thermal diffusivity, density and dynamic viscosity.

Advanced Noise Control Fan Aerodynamic Performance

Abstract: The Advanced Noise Control Fan at the NASA Glenn Research Center is used to experimentally analyze fan generated acoustics. In order to determine how a proposed noise reduction concept affects fan performance, flow measurements can be used to compute mass flow. Since tedious flow mapping is required to obtain an accurate mass flow, an equation was developed to correlate the mass flow to inlet lip wall static pressure measurements. Once this correlation is obtained, the mass flow for future configurations can be obtained from the nonintrusive wall static pressures. Once the mass flow is known, the thrust and fan performance can be evaluated. This correlation enables fan acoustics and performance to be obtained simultaneously without disturbing the flow.