Guowei Liang

A New Method for the Flowrate Measurement of Gas-Liquid Two-Phase Flow

A new method for the flowrate measurement of the gas-liquid two-phase flow is proposed. A multi-circle flowmeter is designed based on the measurement principle of the conventional loop flowmeter. Four differential pressure signals are obtained from the multi-circle sensor at different positions. Multi-parameters of the two-phase flow are obtained. The total flowrate measurement models of the two-phase flow are established using the average values of the differential pressure signals. Four measurement models are compared and the optimal ones are selected to calculate the density and the volume fraction of the mixture. The measurement of the liquid flowrate and the gas flowrate is realized associated with the volume fraction. Experimental results show that the measurement accuracy is satisfactory.

Design of low-power consumption ultrasonic open channel flow meter

The measurement principle of ultrasonic sensor in an open channel flow meter is introduced. A new low-power consumption ultrasonic flow meter, which is based on the MCU of MSP430, is designed for the flowrate measurement of open channels. The measurement characteristics of the Parshall flume are analyzed. The experimental data agree with the relationship between the flowrate and the liquid level in Parshall flume. In order to reduce the power consumption, the running time of CPU is minimized. The algorithm in the program is optimized to avoid floating-point calculation. The operating mode of MSP430 is set to be reasonable. Through the flow calibration experiment, the relevant flowrate measurement model is established. The experiments indicate that electric current is 100uA at working state and that is 10uA at sleeping state. The results show that the error of the instantaneous flow is less than 1.654% and the error of the accumulated flow is less than 1%.

Development of thermal gas mass flowmeter

The measurement principle of thermal gas mass flowmeter was explained in the paper. Design of the thermal gas mass flowmeter based on the MSP430 microcontroller. The flowmeter using assembled platinum-film probe as its sensor, and its flow measuring circuit has the function of temperature compensation. The flow measuring experiment of the flowmeter was tested on Sonic Nozzle. The results of experimental data processing proved that the flowmeter has a wide measuring range, high accuracy and repeatability. The measuring range was 100∶1. From 0.1 Qmax to Qmax, the relative error was less than ±1.5%

Numerical Simulations of Fluidic Flowmeter with Large Measurement Range

A fluidic flowmeter with new structure is designed in this work on the basis of the traditional ones in order to obtain wide measurement range. This fluidic flowmeter has the diffuser wall with polygonal line and it has the performance of adaptability and stability. The CFD software FLUENT is employed to the numerical simulations of the fluidic flowmeter. The linear-relationship of oscillation frequency flowrate is obtained in the wide measurement range through the analysis of the data. The simulation results show that the oscillation of this fluidic flowmeter is stable and reliable. The formula of the flowrate and the oscillation frequency is obtained. The lower limit of the measurement and the pressure loss of the oscillator are also analyzed. Some useful theoretical information can be provided for the design of fluidic flowmeter in this work.

Development of the Multi-point Thermal Gas-mass Flowmeter

A multi-point thermal gas-mass flowrate measurement method is designed. The meter has four hot-film sensoring elements. Four often-used arrangements of the sensing elements are studied and the optimal disposition is selected. The temperature characteristics of the hot-film probe are analyzed under different surrounding temperature conditions and different currents passing through the hot-film probe. The relationship between the resistance of the probe and the ambient temperature is obtained. The automatic compensation method is applied to the temperature compensation. The curve fitting method is employed to calibrate the multi-point thermal gas-mass flowmeter. The gas flowrate is measured according to the output of the sensing elements array through curve fitting. The test results show that the multi-point method is satisfactory

Simulation and design of ultrasonic flow sensor

In order to solve the pipeline influence on measurement accuracy, the software Fluent was introduced to simulate the flow condition of the ultrasonic sensor. Through the simulation of different kinds of pipeline, the ultrasonic signal was analyzed and compared. The final form of the pipeline was obtained and the ultrasonic sensor was designed. The water experiments proved the design is valid.

The study on Measurement Characteristics of fluidic flowmeters sensors with CFD

CFD technology is employed to simulate the fluidic flowmeters. A modified structure, that with double-target and polygonal surface, is proposed. The Measurement Characteristics are compared with the other two fluidic flowmeters, named in the paper meter with single-target, meter with double-target and straight surface. The flow fields are illustrated. The performance and the relationship between the flowrate and the oscillation frequency for each meter are obtained. Some useful theoretical information can be provided for the design and optimization of fluidic flowmeters in this work.

The gas mass flow measurement base on multi-sensor information fusion

In order to solve the problem of the gas flow measurement in large scale pipeline, a multi-sensor measurement based on thermal principle is introduced. The weighted data fusion and temperature fusion algorithms are designed and the mass flow model is established. The four sensorspsila experiments show the precision is improved and the project is valid.

Analysis on Dynamic Differential Pressures of Multi‐Loop Flowmeter for the Measurement of Gas‐Liquid Two‐Phase Flow

A multi‐loop flow sensor with new structure is designed for the parameters measurement of gas‐liquid two‐phase flow. The dynamical differential pressure signals of gas‐liquid two‐phase flow captured from the rising section at the horizontal diameter of the multi‐loop sensor are analyzed. A characteristic value related to the root‐mean‐square of the dynamical differential pressure signals is obtained. The relationship between the characteristic value of differential pressures and the volumetric void fraction is established. The gas density is introduced for the correction of this mode. The experiments were carried out on the horizontal multi‐phase flow loop. The non‐dimensional method was applied to analyze the data. The relationship between the volumetric void fraction and the non‐dimensional value are achieved. The online measurement of the volumetric void fraction of gas‐liquid two‐phase is realized through the multi‐loop flow sensor. The experiments showed that the results are satisfactory.

A Vehicle Platinum-film Air Flow-Sensor Based on Heat Transfer

Based on the heat transfer principle, a new platinum-film air flow-sensor applied to automobiles was developed. The influence of the sensor structure on the heat transfer was analyzed quantitatively. The temperature characteristics of the sensor were studied under different currents through the sensor and different environmental conditions. The relationship between the outputs of the sensor and gas flowrate was obtained. The Experimental research had been carried out to investigate the temperature-compensation performance of the sensor. The results indicated that the design of the temperature-compensation unit and the response speed of the circuit are the crucial factors influencing outputs of the flow-sensor. The gas flowrate based on the designed platinum-film sensor had been applied to vehicle control system successfully. It can meet the requirement of the practical applications