scholarly journals Each-Phase Metering with Gas-Liquid Stratified Flow Based on the Multi-Frequency Coriolis Principle

2020 ◽  
Vol 10 (21) ◽  
pp. 7747
Author(s):  
Chenquan Hua ◽  
Yixiang Yin ◽  
Shuning Sun ◽  
Hao Zhu ◽  
Lanchang Xing
Keyword(s):  
Resonance Effect ◽  
Stratified Flow ◽  
Single Frequency ◽  
Total Density ◽  
Vibrational Modes ◽  
Third Order ◽  
Two Phase ◽  
Mass Flowrate ◽  
Measuring Tube ◽  
Frequency Correction

Gas-liquid two-phase flows generally have the characteristics of complex and variable flow patterns and flow rate uncertainty of each phase. The entrainment of gas increases errors of the existing non-separated multiphase metering. A novel metering method based on the multi-frequency Coriolis principle is proposed to solve the above problems. Compared to the conventional Coriolis mass flowmeter, the third-order mode of the measuring tube is used to improve the accuracy of the measurement. The influences of bubble effect and resonance effect on vibration responses in different vibrational modes were studied to determine the deviations of the apparent values of total density and mass flowrate by simulation. Simulation results with a single-frequency Coriolis flowmeter show that the maximum relative deviations of total density and total mass flowrate are −37.3% and −9.3%, respectively. Driven by different frequencies, the same two phase fluid in the measuring tube can have different responses of the primary mode and the higher vibrational modes. The vibrational responses characteristics corresponding to the first-order and third-order modes of measuring tube were selected and analyzed. Combined with advantages of high precision and multi-parameter measurement of traditional single-frequency Coriolis flowmeters, a multi-frequency correction model suitable for stratified flow was proposed. The results show that the corrected total density and mass flow deviations of gas-containing fluid are within ±4% and ±3%, respectively, which are significantly reduced. Corrected flowrate deviations of the gas-phase and liquid-phase are ±9.1% and ±7.2%, correspondingly, which also meet the metering requirements of the wellhead.

Excess vibrational modes and high thermoelectric performance of the quenched and slow-cooled two-phase alloy Cu0.2Ag2.8SbSeTe2

2011 ◽  
Vol 23 (13) ◽  
pp. 135305
Author(s):  
F R Drymiotis ◽  
S Lindsey ◽  
J Capps ◽  
J C Lashley ◽  
D Rhodes ◽  
...  
Keyword(s):  
Thermoelectric Performance ◽  
Vibrational Modes ◽  
Two Phase

Effect of Variable Heating Load on the Refrigerant Distribution of a Dual Cold-Plate System

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Cheng-Wei Tien ◽  
Kun-Huang Yu ◽  
Wen-Junn Sheu ◽  
Chi-Chuan Wang
Keyword(s):  
Phase Distribution ◽  
Cold Plate ◽  
Two Phase ◽  
Nominal Capacity ◽  
Mass Flowrate ◽  
Heating Load ◽  
Cold Plates ◽  
The Difference ◽  
R 134A ◽  
Plate System

This study examines the refrigerant distribution of a dual cold-plate system subject to the influence of heating load, using a R-134a based vapor compression system with a nominal capacity ranging from 50 W to 250 W. The cold plate is of identical configuration. Initially, test is performed under an equal heating load for each cold plate (70 W), which then gives rise to a uniform distribution and equal outlet superheat condition. For an unequal heating load, it is found that the distribution of mass flowrate subject to the influence of heating load is strongly related to the outlet states of the two cold plates. For the condition where one of the cold plates is in superheated state while the other is in saturated state, the mass flowrate for the fixed heating load is lower than that of smaller heating load, and the difference increases when the heating load gets smaller due to the influence of accelerational pressure drop. A maximum of 17% difference is seen at a loading ratio of 0.571 (40 W/70 W). For the condition where both outlet states of the cold plate are at superheated states, the mass flowrate for the fixed heating load is marginally higher than that of the smaller heating load, and the difference is insensitive to the increase in heating load. For this situation, the effect of accelerational pressure is negligible, and it is mainly attributed to two-phase/single-phase distribution pertaining to the effect of heating load.

Quantification of the RELAP5 Model Uncertainty for Application to the Loss-of-RHR Event During the Mid-Loop Operation

2009 ◽  
Author(s):  
Ikuo Kinoshita ◽  
Hiroichi Nagumo ◽  
Minoru Yamada ◽  
Yasuhiro Sasaki ◽  
Yoshitaka Yoshida
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Model Uncertainty ◽  
Stratified Flow ◽  
Condensation Heat Transfer ◽  
Analysis Method ◽  
Gas Distribution ◽  
Two Phase ◽  
Model Parameter ◽  
Best Estimate

Best estimate analysis method for the loss of Residual Heat Removal (loss-of-RHR) event during the mid-loop operation is being conducted along the Code Scaling, Applicability and Uncertainty (CSAU) evaluation methodology. The analysis method uses RELAP5/MOD3.2 as a best estimate analysis code. One of the important processes in the CSAU methodology is the development of the Phenomena Identification and Ranking Table (PIRT) which identifies thermal-hydraulic phenomena during the event and ranks the identified phenomena from the view point of influence on the safety evaluation parameters. The safety parameters for evaluation are Reactor Coolant System (RCS) pressure and reactor vessel water level. The PIRT for the reflux cooling of the loss-of-RHR event during the mid-loop operation was developed based on existing integral test results, plant analysis results and related papers considering influence on coolant distribution, non-condensible gas distribution and heat transfer. Referenced integral tests are ROSA-IV/LSTF, BETHSY, PKL and IIST. Uncertainty of RELAP5/MOD3.2 physical models related to high ranked phenomena identified in the PIRT for the reflux cooling is quantified using the related experimental data for application to PWR plant statistical analysis based on the developed verification matrix. Uncertainty quantified models are void model, horizontal stratified flow criteria and SG condensation heat transfer. These models are related to the following phenomena respectively. Void model (interfacial friction factor in bubbly and slug flow regimes): - Two phase expansion in core and upper plenum due to core boiling. - Two phase flow to Steam Generator (SG) inlet plenum and U-tubes. Horizontal stratified flow criterion: - Stratification of flow in hot leg. - Water transportation from hot leg to SG by steam flow. SG condensation heat transfer model: - Heat transfer in SG U-tube under presence of non-condensable gas. Distribution of model parameter multiplier which represents model uncertainty was obtained by either experiment analysis by RELAP5 or comparison of separate RELAP5 model prediction to experimental data. Mean value and standard deviation are calculated for distribution of model parameter multiplier.

Graphical Determination of Optimum Trajectories for Third-Order Systems

1970 ◽  
Vol 92 (2) ◽  
pp. 271-278
Author(s):  
Yousri M. Abd-El-Fattah
Keyword(s):  
Control Function ◽  
Maximum Error ◽  
Control Signal ◽  
Graphical Solution ◽  
Third Order ◽  
Two Phase ◽  
State Trajectory ◽  
Optimum Trajectories ◽  
Initial States

The present paper explains the use of two phase planes in the graphical determination of optimum trajectories for third-order systems, depending on the sign of a single control function. The control function is defined on these planes by means of different contours. Accordingly, the control signal is known at the different points on these planes. Once the control signal is found, the state trajectory is determined. Most of the arbitrary initial states are treated and, in particular, the cases of separate steps in each of the error and its first as well as second time derivatives. This work also explains the use of the graphical solution in obtaining the maximum error and switching times.

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