scholarly journals Two-phase pump performance program: pump test facility description

1976 ◽  
Author(s):  
M. V. Couture ◽  
J. D. Fishburn ◽  
J. J. Klebauskas ◽  
H. M. Payne ◽  
E. Richardson ◽  
...  
Author(s):  
Mathew C. Jacob ◽  
Michael T. Coon ◽  
John A. Blaisdell ◽  
Ruben J. Espinosa

Emergency Core Cooling System (ECCS) analyses using Loss of Coolant Accident (LOCA) codes utilize two-phase Reactor Coolant Pump (RCP) performance models formulated on the basis of data from tests conducted on the Semi-scale pump (Reference 1) operating at 60 Hz frequency. In some PWRs, the RCPs operate at a frequency of 50 Hz. This paper presents the results of an evaluation performed to determine the applicability of RCP two-phase performance models developed on the basis of data from the Semi-scale tests for analyzing ECCS performance of new generation PWRs. The evaluation addressed two major issues: (1) the applicability of the two-phase RCP performance model developed using the data from the Semi-scale pump tests (Reference 1) for full scale Pressurized Water Reactor (PWR) LOCA simulations, and (2) the relevance of the two-phase RCP performance model developed on the basis of test data for the Semi-scale pumps running at 60 Hz frequency to PWR RCPs running at 50 Hz frequency with higher specific speeds. Reviews of pump performance test data available in the open literature identified two-phase performance data appropriate for use in substantiating the validity of current PWR pump performance models. These data supported the conclusion that the two-phase head performance degradation for the Semi-scale Mod-1 pump is conservative compared to the two-phase pump performance data generated from testing of pumps representative of full scale PWR RCPs. A review of ECCS analyses results available in the literature determined that the use of the current RCP two-phase performance model (developed using the Semi-scale Mod-1 pump test data) for a typical PWR plant resulted in about a 100 °F increase in the Peak Clad Temperature (PCT) for a Large Break LOCA (LBLOCA) in comparison to the PCTs calculated using the two-phase pump performance model developed on the basis of test data for pumps representative of full scale PWR RCPs. It was determined from the current study that the frequency (50 Hz vs. 60 Hz) of the electrical power that drives the pump motor is not of much consequence for two-phase RCP performance modeling, since (1) the RCP performance model is characterized via normalized pump performance parameters, and (2) for the LBLOCA analysis of interest, the RCPs are assumed to lose power at the start of the event.


2005 ◽  
Vol 127 (4) ◽  
pp. 755-762 ◽  
Author(s):  
Yasushi Tatebayashi ◽  
Kazuhiro Tanaka ◽  
Toshio Kobayashi

The authors have been investigating the various characteristics of screw-type centrifugal pumps, such as pressure fluctuations in impellers, flow patterns in volute casings, and pump performance in air-water two-phase flow conditions. During these investigations, numerical results of our investigations made it clear that three back flow regions existed in this type of pump. Among these, the back flow from the volute casing toward the impeller outlet was the most influential on the pump performance. Thus the most important factor to achieve higher pump performance was to reduce the influence of this back flow. One simple method was proposed to obtain the restraint of back flow and so as to improve the pump performance. This method was to set up a ringlike wall at the suction cover casing between the impeller outlet and the volute casing. Its effects on the flow pattern and the pump performance have been discussed and clarified to compare the calculated results with experimental results done under two conditions, namely, one with and one without this ring-type wall. The influence of wall’s height on the pump head was investigated by numerical simulations. In addition, the difference due to the wall’s effect was clarified to compare its effects on two kinds of volute casing. From the results obtained it can be said that restraining the back flow of such pumps was very important to achieve higher pump performance. Furthermore, another method was suggested to restrain back flow effectively. This method was to attach a wall at the trailing edge of impeller. This method was very useful for avoiding the congestion of solids because this wall was smaller than that used in the first method. The influence of these factors on the pump performance was also discussed by comparing simulated calculations with actual experiments.


2001 ◽  
Author(s):  
C. Frepoli ◽  
A. J. Ireland ◽  
L. E. Hochreiter ◽  
F. B. Cheung

Abstract The droplet injection experiments to be performed in a 7 × 7 rod bundle heat transfer test facility are being simulated using an advanced thermal hydraulics computer code called COBRA-TF. A current version of the code, which provides a three-dimensional, two-fluid, three-field representation of the two-phase flow, is modified to facilitate the simulation of the droplet field produced by the injection system in the test facility. The liquid phase is split into a continuous liquid field and droplet field where a separate momentum and mass equation is solved for each field, with the effects of spacer grids being properly accounted for. Pre-test analyses using the modified COBRA-TF code have been conducted for different injection conditions. Results indicate that there are specific ranges of conditions that can be simulated within the facility constraints to provide for validation of the dispersed flow film boiling models. The numerical results also show important effects of the spacer grids on the local heat transfer in the dispersed flow film boiling regime.


Author(s):  
Youjia Zhang ◽  
Weimin Ma ◽  
Shengjie Gong

This study is concerned with liquid film dynamics and stability of annular flow, which plays an important role in understanding film rupture and dryout in boiling heat transfer. The research work starts from designing and making a test facility which enables the visualization and measurement of liquid film dynamics. A confocal optical sensor is applied to track the evolution of film thickness. A horizontal rectangular channel made of glass is used as the test section. Deionized water and air are supplied into that channel in such a way that an initial stratified flow forms, with the liquid film on the bottom wall. The present study is focused on characterization of liquid film profile and dynamics in term of interfacial wave and shear force induced film rupture under adiabatic condition. Based on the experimental data and analysis, it is found that given a constant water flowrate, the average thickness of water film decreases with increasing air flowrate, while the interfacial wave of the two-phase flow is intensified. As the air flowrate reaches a critical value, a localized rupture of the water film occurs.


Author(s):  
Paul A. Feenstra ◽  
Victor P. Janzen ◽  
Bruce A. W. Smith

Tests are being planned which will use AECL’s MR-3 Freon test facility and a Multi-Span U-Bend (MSUB) test rig to investigate the dynamics of tube vibration in two-phase flow, in particular those mechanisms that can cause excessive damage to steam-generator tubes. In preparation for the tests, free- and forced-vibration tests were conducted to measure the vibration energy dissipation (damping) of a single U-bend tube in air, with dry and wet anti-vibration bars, under a variety of tube-support conditions. This paper presents the relevant damping mechanisms and documents methods used to conduct the tests and to analyze the energy dissipated at the supports. Results indicate that for in-plane motion without tube-to-support contact, viscous damping related to wet AV B supports is much smaller than guidelines based on other types of supports suggest. To begin to examine the effects of the tube coming into contact with its supports, such as friction-related energy dissipation, the results of tests with light tube-to-support preloads are also presented.


Author(s):  
Thuy Chu ◽  
Tan C. Nguyen ◽  
Jihoon Wang ◽  
Duc Vuong

AbstractElectrical Submersible Pump (ESP) is one of the major Artificial Lift methods that is reliable and effective for pumping high volume of fluids from wellbores. However, ESP is not recommended for applications with high gas liquid ratio. The presence of free gas inside the pump causes pump performance degradation which may lead to problems or even failure during operations. Thus, it is important to investigate effect of free gas on ESP performance under downhole conditions. At present, existing models or correlations are based on/verified with experimental data. This study is one of the first attempts to develop correlations for predicting two-phase gas–liquid pump performance under downhole conditions by using field data and laboratory data. Field data from three oil producing wells provided by Strata Production Company and Perdure Petroleum LLC. as well as experimental data obtained from experimental facility at Production and Drilling Research Project—New Mexico Tech were used in this study. Actual two-phase pump differential pressure per stage is obtained from experiments or estimated from field data and was normalized using pump performance curve. The values are compared to pump performance curve to study the relationships between pump performance and free gas percentage at pump intake. Correlations to predict ESP performance in two-phase flow under downhole and experimental conditions was derived from the results using regression technique. The correlation developed from field data presented in this study can be used to predict two-phase ESP performance under downhole conditions and under high gas fraction. The results from the experimental data confirm the reliability of the developed correlation using field data to predict two-phase ESP performance under downhole conditions. The developed correlation using the laboratory data predicts quite well the two-phase pump performance at the gas fraction of less than 15% while it is no longer reliable when free gas fraction is more than 15%. The findings from this study will help operating companies as well as ESP manufacturers to operate ESPs within the recommended range under downhole conditions. However, it is recommended to use the proposed correlation on reservoirs with conditions similar to those of the three presented wells.


Author(s):  
Yasushi Tatebayashi ◽  
Kazuhiro Tanaka ◽  
Toshio Kobayashi

The authors have been investigating the various characteristics of screw-type centrifugal pumps, such as pressure fluctuations in impellers, flow patterns in volute casings, and pump performance in air-water two-phase flow conditions. During these investigations, numerical results of our investigations made it clear that three back flow regions existed in this type of pump. Among these, the back flow from the volute casing toward the impeller outlet was the most influential on the pump performance. Thus the most important factor to achieve higher pump performance was to reduce the influence of this back flow. One simple method was proposed to obtain the restraint of back flow and so as to improve the pump performance. This method was to set up a Ring-like wall at the suction cover casing between the impeller outlet and the volute casing. Its effects on the flow pattern and the pump performance have been discussed and clarified to compare the calculated results with experimental results done under two conditions — namely, one with and one without this Ring-type wall. The influence of wall’s height on the pump head was investigated by numerical simulations. In addition, the difference due to the wall’s effect was clarified to compare its effects on two kinds of volute casing. From the results obtained it can be said that restraining the back flow of such pumps was very important to achieve higher pump performance. Furthermore, another method was suggested to restrain back-flow effectively. This method was to attach a wall at the trailing edge of impeller. This method was very useful for avoiding the congestion of solids because this wall was smaller than that used in the first method. The influence of these factors on the pump performance was also discussed by comparing simulated calculations with actual experiments.


2003 ◽  
Author(s):  
Y. Han ◽  
B. A. W. Smith ◽  
B. V. Luloff

A series of tests in a small-scale loop containing a centrifugal pump was carried out to develop practical acoustic test and analysis techniques to be used in a manufacturer’s pump test facility during pump qualification testing. To determine the pump transmission characteristics, the effect of high noise levels due to the flow was reduced by driving an external source repeatedly with a swept-frequency signal and performing synchronous, time-domain averaging. A new multi-sensor technique is shown to provide accurate estimates of the pump acoustic transfer matrix. Results confirm that the pump transfer matrix is similar whether the pump is running or not. This indicates that the full-scale pump transfer matrix may be determined with the pump off using a relatively weak external acoustic source and a pump loop system with no cavitation.


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