Large-scale air/water flow tests for separate effects during LOCAs in PWRs

1987 ◽  
Vol 102 (2) ◽  
pp. 171-176 ◽  
Author(s):  
Harri Tuomisto
Keyword(s):  
Water Flow ◽  
Large Scale

scholarly journals Ethylene Yield from Pyrolysis Cracking in Olefin Plant Utilizing Regression Analysis

2021 ◽  
Vol 287 ◽  
pp. 03004
Author(s):  
Mohamad Hafizi Zakria ◽  
Mohd Ghazali Mohd Nawawi ◽  
Mohd Rizal Abdul Rahman
Keyword(s):  
Regression Analysis ◽  
Water Flow ◽  
Large Scale ◽  
Nox Emission ◽  
Feed Water ◽  
Yield Model ◽  
Liquid Feed ◽  
The Impact ◽  
Steam Drum ◽  
Boiler Feed Water

Ethylene yield is significant in showing the performance of the steam cracker furnace in the olefin plant. This study was conducted in the actual large-scale olefin plant to see the impact of various variables towards the ethylene yield. The analysis was conducted utilizing Regression Analysis in Minitab Software Version 18 to develop a reliable ethylene yield model. The model concluded that ethylene yield in the studied plant was contributed by the factor of -0.000901, 0.02649, -0.282, 0.16, -0.0834, 0.1268, and 0.0057 of Hearth Burner Flow, Integral Burner Flow, Steam Drum Pressure, Super High-Pressure Steam (SHP) Boiler Feed Water Flow, SHP Flow, Naphtha Feed Flow, and Stack NOx Emission respectively. The Response Optimizer tool also showed that the ethylene yield from naphtha liquid feed utilizing pyrolysis cracking can be maximized at 32.55% with control setting at 9,476.41 kg/hr of Hearth Burner Flow, 608.56 kg/hr of Integral Burner Flow, 112.93 Barg of Steam Drum Pressure, 109.11 t/hr of SHP Boiler Feed Water Flow, 86.42 t/hr of SHP Flow, 63.49 t/hr of Naphtha Feed Flow and 126.23 mg/m3 of Stack NOx Emission.

Variable discharge alters habitat suitability for benthic algae and cyanobacteria in a forested Mediterranean stream

2010 ◽  
Vol 61 (4) ◽  
pp. 441 ◽  
Author(s):  
Elisabet Tornés ◽  
Sergi Sabater
Keyword(s):  
Water Flow ◽  
Large Scale ◽  
Light Availability ◽  
Benthic Algae ◽  
High Water ◽  
Algal Community ◽  
Small Scale ◽  
Low Velocity ◽  
Substratum Type ◽  
Mediterranean Stream

Large-scale algal community patterns can be understood by studying organisation within patches. Spatial heterogeneity in light and substratum type may affect the biomass and community composition of benthic algae and cyanobacteria. We compared the effects of these factors at the species level in two reaches differing in canopy cover in a forested Mediterranean stream in winter (high water flow) and late spring (low water flow). Partial redundancy analyses revealed that the major determinants of species distribution were strongly associated with variations in measured environmental variables. Light availability, the Reynolds number and substratum type were the main factors accounting for the algal and cyanobacterial distribution. Factors affecting algal distribution varied between hydrological periods, suggesting that some species had specific requirements whereas others had a wider tolerance to environmental conditions. Our results demonstrated that the hydraulic conditions (low velocity v. high velocity) influence small-scale heterogeneity in streams, and that this affects benthic community distribution.

scholarly journals EDDA: integrated simulation of debris flow erosion, deposition and property changes

2014 ◽  
Vol 7 (6) ◽  
pp. 7267-7316
Author(s):  
H. X. Chen ◽  
L. M. Zhang
Keyword(s):  
Debris Flow ◽  
Yield Stress ◽  
Water Flow ◽  
Large Scale ◽  
Limit Equilibrium ◽  
Flow Density ◽  
Catchment Scale ◽  
Flow Process ◽  
One Dimensional ◽  
Property Changes

Abstract. Debris flow material properties change during the initiation, transportation and deposition processes, which influences the runout characteristics of the debris flow. A quasi-three-dimensional depth-integrated numerical model, EDDA, is presented in this paper to simulate debris flow erosion, deposition and induced material property changes. The model considers changes in debris flow density, yield stress and dynamic viscosity during the flow process. The yield stress of debris flow mixture is determined at limit equilibrium using the Mohr–Coulomb equation, which is applicable to clear water flow, hyper-concentrated flow and fully developed debris flow. To assure numerical stability and computational efficiency at the same time, a variable time stepping algorithm is developed to solve the governing differential equations. Four numerical tests are conducted to validate the model. The first two tests involve a one-dimensional dam-break water flow and a one-dimensional debris flow with constant properties. The last two tests involve erosion and deposition, and the movement of multi-directional debris flows. The changes in debris flow mass and properties due to either erosion or deposition are shown to affect the runout characteristics significantly. The model is also applied to simulate a large-scale debris flow in Xiaojiagou Ravine to test the performance of the model in catchment-scale simulations. The results suggest that the model estimates well the volume, inundated area, and runout distance of the debris flow. The model is intended for use as a module in a real-time debris flow warning system.

Towing Resistance Calculation of the Cylindrical Drilling Platform

2010 ◽  
Vol 43 ◽  
pp. 142-146
Author(s):  
Yun Wang ◽  
Chao Jun Yang ◽  
Chun Song Guan ◽  
Yan Tu ◽  
Zhen Gang Wang
Keyword(s):  
Water Flow ◽  
Large Scale ◽  
Meteorological Factors ◽  
Air Flow ◽  
Deep Drilling ◽  
Cylindrical Structures ◽  
And Performance

Towing the large-scale drilling platform without self-propulsion is difficult. Towing resistance calculation is necessary for safe pilotage. The tug power decision and the fleet arrangement should be confirmed according to the features and performance of towed vessel, water flow, air flow and other meteorological factors in towing route. The resistance calculations of towed vessel and tugboats are carried out. Whether it is suitable to be towed by the fleet will be verified in accordance with the calculations of the hauling power of tugboats. In this paper, the towing resistance of the cylindrical ultra-deep drilling platform without self-propulsion capability is studied, which could provide reference for other cylindrical structures on the implementation of towing plans.

scholarly journals A Systematic Review of Ontology-Based River Streamflow and Flood Data Management Challenges

2021 ◽  
Vol 19 (1) ◽  
pp. 40-50
Author(s):  
Muhammad H. Mughal ◽  
Zubair A. Shaikh ◽  
Zahid H. Khand ◽  
Asif Rajput ◽  
Faheem Akhtar
Keyword(s):  
Systematic Review ◽  
Water Flow ◽  
Water Distribution ◽  
Large Scale ◽  
Knowledge Integration ◽  
Limiting Factors ◽  
Contextual Knowledge ◽  
Domain Specific ◽  
Management Perspective ◽  
Spatio Temporal

The management of the riverine water has always remained an open challenge. The variation of water flow creates hurdles to determine the exact time and the quantity of water flow caused by the spatio-temporal complex streamflow and flood risk reduction domain. From a management perspective, irregular flow patterns generate various challenges and the development of irrigation water distribution schemes without contextual knowledge integration adversely affect the relevant community. The river streamflow and flood mitigation domains are interdisciplinary that require coordination from the various stakeholders. Coordination limiting factors includes native data acquisition methodology of each stakeholder for their specific needs, the complexity of the domain involving a heterogeneous group of managers, spatio-temporal context, region-specific terminologies, data sharing, and reusability support. Earlier proposed research and developed ontologies by the esteemed researchers focused to address these challenges in a domain-specific context. In this research, we review the challenges of a large scale spatio-temporal system for streamflow of watersheds and flood disaster management based on the ontological semantic models. This research also examines the proposed ontological models for streamflow and/or flood domain, and how they address such challenges. Furthermore, a systematic review of the last two decades’ research articles is conducted and the findings are presented to assess the mappings of the challenges to proposed solutions through ontological modeling for streamflow and flood domain.

scholarly journals Methods of determination of morphological indicators in hydrological calculations in the design of roads and road structures

2021 ◽  
Vol 264 ◽  
pp. 02014
Author(s):  
Barno Salimova ◽  
Abdukhaxxor Tulyaganov ◽  
Raykhan Khakimova ◽  
Pokizakhon Muslimova
Keyword(s):  
Water Flow ◽  
Large Scale ◽  
Main Channel ◽  
Methods Of Determination ◽  
Engineering Problems ◽  
Maximum Water ◽  
Basin Area

In solving the engineering problems in the practice of different specialties, in the design of roads and roads, structures, determining the physiographic conditions of the same regional areas: basin area (F), height (Z), average square difference of basin height (s), slope (J), parameters such as the length of the main channel in the basin (L), the width of the maximum water flow in the basin (V) and its depth (h), that is the determination of the calculated values of morphological indicators, performed using a large-scale map. It allows to estimate the amount of physical-geographical and morphological indicators, analyze their interrelationships, reveal the regions' physical-geographical laws, use them in hydrological calculations in the basin, and determine their values, to apply them in solving engineering problems.

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