Measurement of Pressure Drop in a Liquid Metal Reactor Fuel Assembly

Author(s):  
Seok Ki Choi ◽  
Il Kon Choi ◽  
Kil Yong Lee ◽  
Ho Yun Nam ◽  
Jong Hyeun Choi ◽  
...  

An experimental study has been carried out to measure the pressure drop in a 271-pin fuel assembly of a liquid metal reactor. The rod pitch to rod diameter ratio (P/D) of the fuel assembly is 1.2 and the wire lead length to rod diameter ratio (H/D) is 24.84. Measurements are made for five different sections in a fuel assembly; inlet orifice, fuel assembly inlet, wire-wrapped fuel assembly, fuel assembly outlet and fuel assembly upper region. A series of water experiments have been conducted changing flow rate and water temperature. It is shown that the pressure drops in the inlet orifice and in the wire-wrapped fuel assembly are much larger than those in other regions. The measured pressure drop data in a wire-wrapped fuel assembly region is compared with the existing four correlations. It is shown that the correlation proposed by Cheng and Todreas fits the best with the present experimental data among the four correlations considered.

2003 ◽  
Vol 125 (2) ◽  
pp. 233-238 ◽  
Author(s):  
Seok Ki Choi ◽  
Il Kon Choi ◽  
Ho Yun Nam ◽  
Jong Hyeun Choi ◽  
Hoon Ki Choi

An experimental study has been carried out to measure the pressure drop in a 271-pin fuel assembly of a liquid metal reactor. The rod pitch to rod diameter ratio P/D of the fuel assembly is 1.2 and the wire lead length to rod diameter ratio H/D is 24.84. Measurements are made for five different sections in a fuel assembly; inlet orifice, fuel assembly inlet, wire-wrapped fuel assembly, fuel assembly outlet and fuel assembly upper region. A series of water experiments have been conducted changing flow rate and water temperature. It is shown that the pressure drops in the inlet orifice and in the wire-wrapped fuel assembly are much larger than those in other regions. The measured pressure drop data in a wire-wrapped fuel assembly region is compared with the existing four correlations. It is shown that the correlation proposed by Cheng and Todreas fits best with the present experimental data among the four correlations considered.


2008 ◽  
Vol 130 (5) ◽  
Author(s):  
T. A. Jankowski ◽  
E. N. Schmierer ◽  
F. C. Prenger ◽  
S. P. Ashworth

A simple model is developed here to predict the pressure drop and discharge coefficient for incompressible flow through orifices with length-to-diameter ratio greater than zero (orifice tubes) over wide ranges of Reynolds number. The pressure drop for flow through orifice tubes is represented as two pressure drops in series; namely, a pressure drop for flow through a sharp-edged orifice in series with a pressure drop for developing flow in a straight length of tube. Both of these pressure drop terms are represented in the model using generally accepted correlations and experimental data for developing flows and sharp-edged orifice flow. We show agreement between this simple model and our numerical analysis of laminar orifice flow with length-to-diameter ratio up to 15 and for Reynolds number up to 150. Agreement is also shown between the series pressure drop representation and experimental data over wider ranges of Reynolds number. Not only is the present work useful as a design correlation for equipment relying on flow through orifice tubes but it helps to explain some of the difficulties that previous authors have encountered when comparing experimental observation and available theories.


2016 ◽  
Vol 298 ◽  
pp. 218-228 ◽  
Author(s):  
E. Merzari ◽  
P. Fischer ◽  
H. Yuan ◽  
K. Van Tichelen ◽  
S. Keijers ◽  
...  

Author(s):  
Xianliang Lei ◽  
Huixiong Li ◽  
Shuiqing Yu ◽  
Yifan Zhang ◽  
Tingkuan Chen

With the development of supercritical (and even ultra-supercritical) pressure boilers (SCBs) with high capacities, and at the same time, with the consideration of supercritical pressure water-cooled reactors (SCWRs) as one of the six most promising reactor concepts accepted in the Generation IV International Forum (GIF), flow and heat transfer of supercritical water becomes more and more important for both the design and operation safety of the related facilities. Thermo-hydraulic characteristics are among the issues, which are of special significance for the SCBs and SCWRs. It has been found that at supercritical pressures, the hydraulic resistance of water exhibits special characteristics in regions near its pseudo-critical point, which is hereafter called the minimum drag coefficient phenomenon. Experimental investigation was carried out in the present study to investigate further the characteristics of drag coefficient of supercritical pressure water under different conditions. The total pressure drop characteristic of water flowing in smooth tube and internally ribbed tube under the supercritical pressures was measured in experiments with a wide range of operational parameters, such as the system pressures ranging from 23 to 28 MPa, the average heat fluxes varied from 100 kW/m2 to 500kW/m2, and the mass fluxes of water in a range of 600 ∼ 1050 kg/m2s. The experimental data were compared with prediction results calculated by existing common correlations for single phase pressure drops, and large discrepancies were observed between the experimental data and the prediction results. Furthermore, the pressure drops characteristics of supercritical pressure water in cases with different tube arrangement and test conditions were compared with each other, such as that in horizontal tubes and vertical tubes, and that in isothermal flows and in non-isothermal flows. Additionally, this phenomenon observed in the present studies was also analyzed by using computational fluid dynamics technology, and the mechanism of pressure drop variation was reasonably explained. It was found that the deviation appeared between the previously proposed drag coefficient correlations and the present experimental data was mainly owning to ignoring the variation of an existence of the minimum drag coefficient in the pseudo critical region in previous studies, and based on the data obtained in this study, a new correlation for drag coefficient for supercritical pressure water was presented.


1988 ◽  
Vol 110 (1) ◽  
pp. 68-76 ◽  
Author(s):  
R. S. Kistler ◽  
J. M. Chenoweth

A unique set of heat exchanger shellside pressure drop experimental data has become available from experiments at Argonne National Laboratory as a part of an ongoing research program in flow-induced vibration. These data provide overall pressure drop for a number of typical industrial heat exchanger configurations in addition to incremental pressure drop measurements along the shellside path. The test program systematically varied the baffle spacing, the tubefield pattern, and nozzle size for a series of isothermal water tests for segmentally baffled bundles. Also recently a comprehensive method has been published in the Heat Exchanger Design Handbook (HEDH) for the prediction of bundle shellside pressure drops. A search of the literature failed to reveal a complementary method for predicting the shellside nozzle pressure losses. This paper compares the predicted with the measured data and validates the adequacy and limitations of the HEDH method for full bundles of plain tubes. It further applies an extension to the method for no-tubes-in-the-window bundles. Adjustments were indicated to improve the predictions for finned tubes and methods were developed to predict shellside nozzle pressure drops. Overall pressure drop predictions were within plus or minus 20 percent.


Author(s):  
M. Mudasar Imam ◽  
Mehaboob Basha ◽  
S. M. Shaahid ◽  
Aftab Ahmad ◽  
Luai M. Al-Hadhrami

The pressure drop of liquids of different viscosities in multiphase flow is still a subject of research. This paper presents pressure drop measurements of water and oil single phase flow in horizontal and inclined 4 inch diameter stainless steel pipe at different flow rates. Potable water and Exxol D80 oil were used in the study. Experiments were carried out for different inclination angles including; 0°, 15°, 30° (upward and downward flows). Inlet liquid velocities were varied from 0.4 to 1.2 m/s and reference pressure was set at 1 bar. Water and Oil viscosities are 0.798 Pa.s and 1.56 Pa.s at 30°C, respectively. Pressure drop has been found to increase with increase in liquid velocity. Pressure drop has been observed to increase asymptotically with pipe inclination. Upward flows are associated with high pressure drop as compared to downward flows. The pressure drop of water is greater than that of oil for all inclinations. This difference can be attributed to the difference in fluid viscosities and densities. Measured pressure drops were compared with existing empirical relations and good agreement was noticed.


2012 ◽  
Vol 29 (2) ◽  
pp. 115 ◽  
Author(s):  
N.Z Aung ◽  
T Yuwono

Nine existing mixture viscosity models were tested for predicting a two-phase pressure drop for oil-water flow and refrigerant (R.134a) flow. The predicted data calculated by using these mixture viscosity models were compared with experimental data. Predicted data from using one group of mixture viscosity models had a good agreement with the experimental data for oil-water two-phase flow. Another group of viscosity models was preferable for gas-liquid flow, but these models gave underestimated values with an error of about 50%. A new and more reliable mixture viscosity model was proposed for use in the prediction of pressure drop in gas-liquid two-phase flow.


Author(s):  
SEUNG-HWAN SEONG ◽  
SEOP HUR ◽  
JAE-CHANGE PARK ◽  
SEONG-O KIM

2004 ◽  
Vol 127 (2) ◽  
pp. 388-392 ◽  
Author(s):  
Ho-Yun Nam ◽  
Jong-Man Kim ◽  
Kyung-Won Seo ◽  
Seok-Ki Choi

An experimental study has been carried out to measure the pressure loss at the side orifice of a liquid metal reactor fuel assembly. The characteristics of the pressure loss at the side orifice are investigated using the experimental data measured from 17 different types of side orifices that have different geometric shapes, dimensions, and arrangements of nozzles, and a correlation that covers the whole flow range by one equation is developed. The error range of the correlation is within ±10%, and most of the errors occurred in a region where the Reynolds number is small. The range of Reynolds numbers based on the hydraulic diameter of the orifice is 2000–350,000. It is found that the geometric factor is the most important parameter for the pressure loss when the Reynolds number is >30,000. As the Reynolds number becomes smaller, its effect becomes larger, and when the Reynolds number is small, it is the most important parameter for the pressure loss at the side orifices. The measured data shows a trend that the pressure loss coefficient increases as the number of orifices increases, and the effect of the longitudinal arrangement is small.


Author(s):  
Akiomi Ushida ◽  
Tomiichi Hasegawa ◽  
Takatsune Narumi ◽  
Toshiyuki Nakajima

Drag reduction effect for microbubble mixtures flows has been investigated and reported. However, few studies have focused on nanobubble mixtures, which have sub-micron meter size fine bubbles. In the present study, nanobubble mixtures for water and glycerol solution were passed through several sizes of micro-apertures, and the resultant pressure drops, as compared with water and glycerol solution alone, were evaluated. For small apertures, the experimentally measured pressure drop was less than that for water and glycerol alone. This phenomenon is considered in terms of interface behavior and attributed to the electric interaction between an electric double layer and fine bubbles. The results of the present study suggest that the addition of nanobubbles to a liquid results in excellent drag reduction.


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