Vertical Tube Passive Condenser Under Secondary Pool Water Level Transient

2010 ◽  
Author(s):  
Shripad T. Revankar ◽  
Wenzhong Zhou
Keyword(s):  
Water Level ◽  
Cooling System ◽  
Vertical Tube ◽  
Test Facility ◽  
Flow Mode ◽  
Scaling Analysis ◽  
Water Level Change ◽  
Level Change ◽  
Pool Water ◽  
System Pressure

An experimental work was carried out on a passive containment cooling system (PCCS) test facility where the effect of PCCS pool water level change on the PCCS heat transfer characteristics was investigated. The specific design of condensing tube was based on scaling analysis from the PCCS design of Economic Simplified Boiling Water Reactor (ESBWR). The annulus between the primary condensing tube and the secondary boiling tube is filled with water and serves as water pool. During the test, steam generated in the pool is discharged through three steam exit nozzles located symmetrically at the top of the secondary boiling tube. Transient tests carried out with secondary pool water level change show that the system pressure for complete condensation mode increases with decrease in water level, however rate of condensation is almost constant. However, if the PCCS is operated in through flow mode the system pressure (primary side pressure) is constant, however, the condensate rate decreases indicating that some of the steam does not condense.

Evaluation of the Scaling Analysis Model of the EU-APR1400 Core Catcher Cooling System Test Facility

2014 ◽  
Author(s):  
Bo W. Rhee ◽  
K. S. Ha ◽  
R. J. Park ◽  
J. H. Song
Keyword(s):  
Performance Test ◽  
Cooling System ◽  
Reactor Core ◽  
Test Facility ◽  
Scaling Analysis ◽  
Analysis Model ◽  
System Pressure ◽  
Test Loop ◽  
Core Catcher ◽  
The Eu

This paper describes the basic design features of the EU-APR1400 reactor core catcher cooling system and its test facility, and the associated scaling analysis model. An assessment of the validity of the scaling analysis using the preliminary performance test result of the test facility is described. This includes comparison of the predicted mass flow rate of the test loop as a function of the heat load to the facility, inlet flow subcooling and system pressure to the experimental results.

Experimental Study of Effects of Non-Condensable on Condensation in a Vertical Tube Bundle

2009 ◽  
Author(s):  
Wenzhong Zhou ◽  
Gavin Henderson ◽  
Shripad T. Revankar
Keyword(s):  
Heat Transfer ◽  
Cooling System ◽  
Tube Bundle ◽  
Condensation Heat Transfer ◽  
Forced Flow ◽  
Test Facility ◽  
Flow Mode ◽  
Scaling Analysis ◽  
Condenser Tube ◽  
Air Concentration

One of the engineered safety systems in the advanced boiling water reactor is a passive containment cooling system (PCCS) which is composed of a number of vertical heat exchanger. After a loss of coolant accident, the pressurized steam discharged from the reactor and the noncondensable (NC) gases mixture flows into the PCCS condenser tube. The PCCS condenser must be able to remove sufficient energy from the reactor containment to prevent containment from exceeding its design pressure. The efficient performance of the PCCS condenser is thus vital to the safety of the reactor. In PCCS condenser tube three flow conditions are expected namely the forced flow, cyclic venting and complete condensation modes. The PCCS test facility consists of steam generator (SG), instrumented condenser with secondary pool boiling section, condensation tank, suppression pool, storage tank, air supply line, and associated piping and instrumentation. The specific design of condensing tube is based on scaling analysis from the PCCS design of ESBWR. The scaled PCCS is made of four tubes of diameter 52.5mm and height 1.8 m arranged in square pitch. Steam air mixture condensation tests were carried out in a through flow mode of operation where the mixture flows through the condenser tube with some steam condensation. Data on condensation heat transfer were obtained for two nominal pressures, 225 kPa and 275 kPa and for air concentration fraction from 0 to 13%. Test results showed that with increase in pressure the condensation heat transfer increased. The presence of the air in the steam decreased the condensation heat transfer coefficient from 10 to 45% depending on air fraction in the steam.

Field relations among coseismic ground motion, water level change and liquefaction for the 1999 Chi-Chi (Mw= 7.5) earthquake, Taiwan

2003 ◽  
Vol 30 (17) ◽  
pp. n/a-n/a ◽  
Author(s):  
Chi-Yuen Wang ◽  
Douglas S. Dreger ◽  
Chung-Ho Wang ◽  
Daniel Mayeri ◽  
James G. Berryman
Keyword(s):  
Water Level ◽  
Ground Motion ◽  
Water Level Change ◽  
Level Change

scholarly journals Climate change or regional human impacts? remote sensing tools, artificial neural networks, and wavelet approaches aim to solve the problem

2020 ◽  
Author(s):  
Ehsan Foroumandi ◽  
Vahid Nourani ◽  
Elnaz Sharghi
Keyword(s):  
Remote Sensing ◽  
Neural Networks ◽  
Time Series ◽  
Artificial Neural Networks ◽  
Water Level ◽  
Positive Trend ◽  
Water Level Change ◽  
Lake Urmia ◽  
Level Change ◽  
Artificial Neural

Abstract Lake Urmia, as the largest lake in Iran, has suffered from water-level decline and this problem needs to be investigated accurately. The major reason for the decline is controversial. The current paper aimed to study the hydro-environmental variables over the Lake Urmia basin using remote sensing tools, artificial neural networks, wavelet transforms, and Mann–Kendall trend tests from 1995 to 2019 in order to determine the primary reason of the decline and to find the most important hydrologic periodicities over the basin. The results indicated that for the monthly-, seasonally-, and annually-based time series, the components with 4-month and 16-month, 24- and 48-month, and 2- and 4-year, respectively, are the most dominant periodicities over the basin. The agricultural increase according to the vegetation index and evapotranspiration and their close relationship with the water-level change indicated that human land-use is the main reason for the decline. The increasing agriculture, in the situations that the precipitation has not increased, caused the inflow runoff to the lake to decline and the remaining smaller discharge is not sufficient to stabilize the water level. Temperature time series, also, has experienced a significant positive trend which intensified the water-level change.

Spatiotemporal change of water level in ungauged high-altitude tropical lakes: a DInSAR approach

2021 ◽  
Author(s):  
Sebastián Palomino-Ángel ◽  
Raúl F. Vázquez ◽  
Henrietta Hampel ◽  
Jesús A. Anaya-Acevedo ◽  
Pablo V. Mosquera ◽  
...  
Keyword(s):  
High Altitude ◽  
Water Level ◽  
Mountain Range ◽  
Similar Data ◽  
Water Level Change ◽  
Level Change ◽  
Water Level Changes ◽  
Basin Scale ◽  
High Altitude Lake ◽  
Lake Systems

<p>Spatiotemporal characteristics of physical responses of lakes to external and environmental changes are still largely unknown due to the consistent lack of monitoring of water level and corresponding changes in water storage in lakes. Understanding these changes is a fundamental step in advancing regional management of natural and anthropogenic systems that depend on the water resources of lakes. As an illustrative example, we here report a case study involving lakes of the headwater topical Andes mountain range, which, despite guaranteeing water security to millions of downstream inhabitants, still remain significantly ungauged. We present a novel evaluation of the potential of Differential Interferometric Synthetic Aperture Radar DInSAR techniques for the spatiotemporal analysis of patterns of water level change in lakes such as the ones comprising these ungauged high-altitude lake systems. Time series of Sentinel-1B data for the years 2017 and 2018 were used to generate continuous interferograms representing water level changes in twenty-four lakes of the Cajas National Park, Ecuador. The relation of these water level changes with climatic and topographical factors were analyzed to validate the methodology, and determine any patterns of change and response to climatic drivers. We found relatively high Pearson correlation coefficients between regional precipitation and water level change as estimated from the interferograms. Furthermore, we found an important negative relationship between water level change, as obtained from the DInSAR phase, and lake surface area. The study revealed a spatial trend of this correlation in terms of the altitude of the lakes at the basin scale; that is, lower correlation values were found in the headers of the basins, whilst higher correlation values were found at lower basin altitudes. The results of the present study demonstrate the potential of DInSAR techniques based on Sentinel-1 data for the monitoring of hydrologic changes in open water surfaces, and the possible validation of the DInSAR results with precipitation when gauged water level data is missing. These results are a basis to propose monitoring strategies in ungauged high-altitude lake systems in regions with similar data gauging constraints. Future work will encompass the integration of ongoing water level gauging for further validation of the herein depicted lake water level estimation approach.</p>

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