Analysis of Orifice Plate Differential Pressure Noise in Horizontal and Vertical Rising Gas-Water Two-Phase Flow

2010 ◽  
Author(s):  
Xianfa Li ◽  
Shuoping Zhong ◽  
Yanfei Sun
Keyword(s):  
Flow Rate ◽  
Two Phase Flow ◽  
Water Flow Rate ◽  
Differential Pressure ◽  
Orifice Plate ◽  
Vapor Flow ◽  
Phase Flow ◽  
Square Root ◽  
Two Phase ◽  
The Difference

It is an important achievement of modern techniques to determine the mass flow rate and the phase fraction of wet steam by measuring the orifice plate differential pressure noise. The orifice plate differential pressure noise of air-water two-phase flow in horizontal and vertical rising pipelines were analyzed. Kinds of calculation methods were tried to get the differential pressure noise. From the difference waveform of the differential pressure square root that the acquisition card got and the mean square root of the sample that got before, the first in first out (FIFO) principle was used to get the differential pressure noise. Result shows that the differential pressure noise has different level at different vapor flow rate with the same water flow rate, conclusions show that the two-parameter measurement by using orifice plate differential pressure noise may be possibly used in vertical rising gas-water two phase flow.

Influences of Impeller Diameter and Diffuser Blades on Air-Water Two-Phase Flow Performance of Centrifugal Pump

2005 ◽  
Author(s):  
Naoki Matsushita ◽  
Akinori Furukawa ◽  
Kusuo Okuma ◽  
Satoshi Watanabe
Keyword(s):  
Centrifugal Pump ◽  
Water Flow ◽  
Flow Rate ◽  
Rotational Speed ◽  
Flow Condition ◽  
High Performance ◽  
Two Phase Flow ◽  
Water Flow Rate ◽  
Phase Flow ◽  
Two Phase

A tandem arrangement of double rotating cascades and single diffuser cascade, proposed as a centrifugal pump with high performance in air-water two-phase flow condition, yields lower head due to the smallness of the impeller outlet in comparison with a impeller with large outlet diameter and no diffuser. Influences of impeller diameter change and installation of diffuser blades on two-phase flow performance were experimentally investigated under the case of the same volute casing. As the result, the similarity law of the diameter of impeller having the similar blade geometry and the rotational speed is satisfied even in two-phase flow condition. Comparing pump performances between a large impeller without diffuser blades and a small one with diffuser blades, higher two-phase flow performance is obtained by controlling the rotational speed of a small impeller with diffuser blades in the range of small water flow rates, while a large impeller with no diffuser gives high performance in the range of high water flow rate and small air flow rate.

Wet Gas Flow Metering Based on Differential Pressure and BSS Techniques

2011 ◽  
Vol 383-390 ◽  
pp. 4922-4927
Author(s):  
Peng Xia Xu ◽  
Yan Feng Geng
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Liquid Flow Rate ◽  
Differential Pressure ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Metering ◽  
Wet Gas

Wet gas flow is a typical two-phase flow with low liquid fractions. As differential pressure signal contains rich information of flow parameters in two-phase flow metering, a new method is proposed for wet gas flow metering based on differential pressure (DP) and blind source separation (BSS) techniques. DP signals are from a couple of slotted orifices and the BSS method is based on time-frequency analysis. A good relationship between the liquid flow rate and the characteristic quantity of the separated signal is established, and a differential pressure correlation for slotted orifice is applied to calculate the gas flow rate. The calculation results are good with 90% relative errors less than ±10%. The results also show that BSS is an effective method to extract liquid flow rate from DP signals of wet gas flow, and to analysis different interactions among the total DP readings.

Visual Criteria for Measuring Two-phase Flow Rate in Venturi with Flow Homogenizer

2015 ◽  
Vol 137 (8) ◽  
Author(s):  
Sangho Sohn ◽  
Jaebum Park ◽  
Dong-Wook Oh
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Two Phase Flow ◽  
Volume Fraction ◽  
Differential Pressure ◽  
Phase Flow ◽  
Two Phase ◽  
3 Dimensional ◽  
Lower Amplitude ◽  
Gas Volume

A simple use of Venturi might be used to measure two-phase flow rate within relatively low GVF(gas volume fraction). Upstream flow entering Venturi can be improved with installed flow homogenizer which is easily fabricated by 3-dimensional printer with multiple holes. Simultaneous measurement between high-speed flow visualization and dynamic differential pressure measurement was made to find visual criteria for two-phase flow rate measurement with different GVF ranged from 0% to 30%. It was observed that the two-phase flow rate can be reliably measured up to 15% of GVF using flow homogenizer. FFT(Fast-Fourier Transform) results proved that the long flow homogenizers (type 2 and 4) showed a lower amplitude of differential pressure (Δp) than the short flow homogenizers (type 1 and 3) respectively. So the optimized flow homogenizer can be useful to measure two-phase flow rate at low GVF.

Development of Air/Water Two-Phase Flow Centrifugal Pump and Its Operating Characteristics

2003 ◽  
Author(s):  
Akinori Furukawa ◽  
Satoshi Ohshita ◽  
Kusuo Okuma ◽  
Satoshi Watanabe
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Two Phase Flow ◽  
Air Flow ◽  
Water Flow Rate ◽  
Phase Flow ◽  
Air Flow Rate ◽  
Operating Characteristics ◽  
Two Phase ◽  
Flow Pump

A centrifugal impeller, the pumping action of which could be highly kept even at an air-water two-phase flow condition of inlet void fraction more than 30% in the region of relatively high water flow rate, has been developed. In the present paper, the design concept of two-phase flow impeller is described, at first, with experimental results. The short bladed forward impeller with high outlet blade angle was decided to keep theoretical head higher even in two-phase flow condition and to disperse the air accumulating region on the suction blade surface by the water jet flow coming from the pressure side. Furthermore, the tandem arrangement of outer and inner rotating cascades with the same blade numbers was adopted to suppress the rotating stall phenomena appearing in the case of a single stage of outer cascade. It should be noted that these results were obtained with operating a boost pump installed upstream of mixing section of air and water, that is not an actual operation of two-phase flow pump. Secondly, the operating characteristics of this two-phase flow pump with change of air flow rate were investigated experimentally without operating the boost pump. As the trajectory of operating point with increasing air flow rate appears along the resistance curve of piping system, the impossibility of pumping occurs at lower air flow rate even though pump head takes a positive value at high air flow rate with increasing water flow rate. It is recognized that it is necessary to improve two-phase flow head characteristic curves in the region of low water flow rate to operate in wider two-phase flow conditions.

Experimental Study on the Void Fraction of Siphon Breaking Process

2017 ◽  
Author(s):  
Lei Xing-lin ◽  
Huang Shan-fan ◽  
Guo Zhong-xiao ◽  
Guo Xiao-yu
Keyword(s):  
Void Fraction ◽  
Flow Rate ◽  
Nuclear Power ◽  
Two Phase Flow ◽  
Water Flow Rate ◽  
Experimental Results ◽  
Physical Parameters ◽  
Phase Identification ◽  
Phase Flow ◽  
Two Phase

As a safety device to alleviate the loss of reactor coolant, the siphon breaking system is widely used in nuclear power plant. Researchers are very interested in this technique for its “passive” characteristic. Vertical downward air-water two-phase flow is encountered in the siphon breaking process. Previous researches have been more focused on some physical parameters, such as water flow rate, air flow rate, pressure drop and the undershooting height. Void fraction, as a key parameter in multiphase flow, should be studied in the siphon breaking phenomenon. Therefore, a needle-contact capacitance probe is used for flow-phase identification and a single-wire capacitance for obtaining the average value of gas distribution along the straight line. Experimental results show that the flow pattern during the vertical downward air-water two-phase flow is mostly annular flow. With the gas entering the pipeline, void fraction profile against time can be divided into three stages. The slope in the first stage is similar to that in the third. However, the slope slows down in the middle stage. The experimental results also show that the real duration time to break the siphon flow is as short as about 6 s. The void fraction at the end of the siphon breaking process is about 0.38. During this stage, a large amount of gas is sucked into the downcomer and little water is inhaled. The gas phase results in a convergent effect, where the air intake is the direct and fundamental reason of siphon breaking.

Model analysis for differential pressure two-phase flow rate meter in intermittent flow

2021 ◽  
pp. 102017
Author(s):  
S.P. Pellegrini ◽  
A.N. Wrasse ◽  
M.J. da Silva ◽  
R.E.M. Morales ◽  
F.C. Trigo ◽  
...  
Keyword(s):  
Flow Rate ◽  
Two Phase Flow ◽  
Model Analysis ◽  
Differential Pressure ◽  
Intermittent Flow ◽  
Phase Flow ◽  
Two Phase

Study on Characteristics of Gas-Liquid Two Phase Flow Distribution in Vertical Manifolds

2010 ◽  
Author(s):  
Cheng Sheng ◽  
Tao Zhou ◽  
Liping Pang ◽  
Yanping Huang
Keyword(s):  
Flow Pattern ◽  
Flow Rate ◽  
Working Condition ◽  
Two Phase Flow ◽  
Water Flow Rate ◽  
Flow Distribution ◽  
Phase Flow ◽  
Two Phase ◽  
Rate Distribution ◽  
Two Phases

This paper shows the experiments of the flow rate distribution measurements of air-water two-phase flow in vertical multi-branch carried out on the Gas-liquid two-phase flow fluid and flow rate distribution experimental platform, and discusses the laws and the Characteristics of two phase flow distribution in the multi-branch by changing the water flow rate or the air flow rate under the condition of fix the flow rate of the other phase, then analyzes the degree of the flow deviation of both two phases in branches by calculating the standard deviations of each working condition. The experiments show that the flow distributions of both two phases are very uneven. There was much air but little water flows into the branches which were close to the inlets of the distributor, but in the branches which were far away from the inlets of the distributor, the situation was opposite to the previous one. The types of the flow pattern in each branch in every working condition were obtained through the Hewitt-Robert flow pattern picture. As the flow rate of air increased, the annular pattern would spread from the branches which are close to the inlets of the distributor to the ones which are far away from the inlets of the distributor.

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