Preliminary Performance Test of Mechanical Pump for a Stella-1

2013 ◽  
Author(s):  
Ji-Woong Han ◽  
Bock Seong Ko ◽  
Sang-Jun Park ◽  
YoonSang Lee ◽  
Ji-Young Jeong ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Performance Test ◽  
Scaling Law ◽  
Water Environment ◽  
Test Loop ◽  
Integral Effect ◽  
Scaling Parameters ◽  
Mechanical Pump ◽  
Two Stages

In the process of sodium-cooled fast reactor (SFR) design, it is very important to verify thermo-hydraulic performance of each component in the sodium environment. In KAERI (Korea Atomic Energy Research Institute) STELLA (Sodium Integral Effect Test Loop for Safety Simulation and Assessment) project is under a Mid- and Long-term Nuclear R&D Program. The STELLA project is composed of two stages. In the 1st stage the performance for heat exchangers such as DHX (Decay heat exchanger) and AHX (Air heat exchanger) and for PHTS (Primary heat transport system) mechanical pump will be evaluated. The detailed design of each component is based on that of a 600MWe demonstration reactor. Since full-scale components could not be installed in STELLA-1 [1], the model pump is designed to be scaled-down based on the scaling law. Various pump tests have been done in water environment by using model pump. In this study the design features of model pump were described and the scaling parameters were examined. The results of pump performance tests have been also introduced which is essential to perform safety analysis.

Construction of a High Temperature Grade 91 Sodium Component Test Loop

2010 ◽  
Vol 654-656 ◽  
pp. 416-419
Author(s):  
Hyeong Yeon Lee ◽  
Jae Han Lee ◽  
Tae Ho Lee ◽  
Jae Hyuk Eoh Lee ◽  
Tae Joon Kim ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Fast Reactor ◽  
Large Scale ◽  
Performance Test ◽  
Heat Removal ◽  
Test Facility ◽  
Decay Heat ◽  
Test Loop ◽  
Intermediate Heat Exchanger ◽  
Grade 91

A large scale sodium test facility of ‘CPTL’(Component Performance Test Loop) for simulating thermal hydraulic behavior of the Korean demonstration fast reactor components such as IHX(Intermediate Heat Exchanger), DHX(Decay Heat Removal Heat Exchanger) and sodium pump under development by KAERI is to be constructed. The design temperature of this test loop is 600°C and design pressure is 1MPa. The three heat exchangers are made of Grade 91 steel. Another sodium test facility of the ‘STEF’(Sodium Thermal-Hydraulic Experimental Facility) will be constructed next to the CPTL facility to simulate the passive decay heat removal behavior in the sodium cooled fast reactor. In this paper, the overall facility features of the CPTL and STEF are introduced and preliminary conceptual design of the facilities are carried out.

Analysis of Long-Term and Thermal Cycling Tests for a Commercial Solid Oxide Fuel Cell

2017 ◽  
Vol 14 (4) ◽  
Author(s):  
Dustin Lee ◽  
Jing-Kai Lin ◽  
Chun-Huang Tsai ◽  
Szu-Han Wu ◽  
Yung-Neng Cheng ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Thermal Cycling ◽  
Solid Oxide Fuel Cell ◽  
Coefficient Of Thermal Expansion ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Flow Rates ◽  
Degradation Rates ◽  
Two Stages

The effects of isothermally long-term and thermal cycling tests on the performance of an ASC type commercial solid oxide fuel cell (SOFC) have been investigated. For the long-term test, the cells were tested over 5000 h in two stages, the first 3000 h and the followed 2000 h, under the different flow rates of hydrogen and air. Regarding the thermal cycling test, 60 cycles in total were also divided into two sections, the temperature ranges of 700 °C to 250 °C and 700 °C to 50 °C were applied for the every single cycle of first 30 cycles and the later 30 cycles, respectively. The results of long-term test show that the average degradation rates for the cell in the first 3000 h and the followed 2000 h under different flow rates of fuel and air are 1.16 and 2.64%/kh, respectively. However, there is only a degradation of 6.6% in voltage for the cell after 60 thermal cycling tests. In addition, it is found that many pores formed in the anode of the cell which caused by the agglomeration of Ni after long-term test. In contrast, the vertical cracks penetrating through the cathode of the cell and the in-plane cracks between the cathode and barrier layer of the cell formed due to the coefficient of thermal expansion (CTE) mismatch after 60 thermal cycling tests.

Upgrade and Shakedown Test of a High Temperature Fluoride Salt Test Loop

2018 ◽  
Author(s):  
Xiangbo Kong ◽  
Yuan Fu ◽  
Jianyu Zhang ◽  
Huiju Lu ◽  
Naxiu Wang
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Heat Exchanger ◽  
Flow Rate ◽  
Storage Tank ◽  
Base Alloy ◽  
High Vacuum ◽  
Electric Heater ◽  
Batch Mode ◽  
Test Loop

A FLiNaK high temperature test loop, which was designed to support the Thorium Molten Salt Reactor (TMSR) program, was constructed in 2012 and is the largest engineering-scale fluoride loop in the world. The loop is built of Hastelloy C276 and is capable of operating at the flow rate up to 25m3/h and at the temperature up to 650°C. It consists of an overhung impeller sump-type centrifugal pump, an electric heater, a heat exchanger, a freeze valve and a mechanical one, a storage tank, etc. Salt purification was conducted in batch mode before it was transferred to and then stored in the storage tank. The facility was upgraded in three ways last year, with aims of testing a 30kW electric heater and supporting the heat transfer experiment in heat exchanger. Firstly, an original 100kW electric heater was replaced with a 335kW one to compensate the overlarge heat loss in the radiator. A pressure transmitter was subsequently installed in the inlet pipe of this updated heater. Finally, a new 30kW electric heater was installed between the pump and radiator, the purpose of which was to verify the core’s convective heat transfer behavior of a simulator design of TMSR. Immediately after these above works, shakedown test of the loop was carried out step by step. At first the storage tank was gradually preheated to 500°C so as to melt the frozen salt. Afterwards, in order to make the operation of transferring salt from storage tank to loop achievable, the loop system was also preheated to a relatively higher temperature 530°C. Since the nickel-base alloy can be severely corroded by the FLiNaK salt once the moisture and oxygen concentration is high, vacuum pumping and argon purging of the entire system were alternatively performed throughout the preheating process, with the effect of controlling them to be lower than 100ppm. Once the salt was transferred into the loop, the pump was immediately put into service. At the very beginning of operation process, it was found that flow rate in the main piping could not be precisely measured by the ultrasonic flow meter. Ten days later, the pump’s dry running gas seal was out of order. As a result, the loop had to be closed down to resolve these issues.

scholarly journals Cost Effectual Distributed Cooperative Cluster based Communication Protocol in Wireless Sensor Network

2020 ◽  
Vol 8 (6) ◽  
pp. 5652-5656
Keyword(s):  
Communication Protocol ◽  
Wireless Sensor ◽  
Team Leaders ◽  
Great Strength ◽  
Second Stage ◽  
Remote Sensor ◽  
Channel Distortion ◽  
Two Stages ◽  
Intense Research

Theoretical energy recognition in remote sensor systems has received intense research interest in the late years. Radio variation, channel distortion, and blockage bring great strength and responsiveness to packets broadcast over a remote channel. A twin innovation is effective communication that can drastically increase the channel range and reduce transmission vigor consumption in disrupting channel. Growth in the direct range brings with it a reduced fault rate. In this paper, an acceptable correspondence method is proposed for each tab with active sending and receiving clusters. It consists of two stages, the precise routing phase, the selective and transmitting stage. In the routing phase, the basic route between the source and the sink hub is started. In the second stage, centers of fundamental development toward flattering team leaders select additional touch centers with minimal biomass costs from their surroundings, and then spread from bundle to cluster to the recently established endurance cluster. Reductions in error rate and regeneration are proven by the fact that malpractice funds become long-term obligation systems.

scholarly journals Competitiveness analysis of Czech agrarian foreign trade in the context of world agrarian market and agrarian trade of EU-27 countries

2010 ◽  
Vol 58 (6) ◽  
pp. 503-514
Author(s):  
Miroslav Svatoš ◽  
Luboš Smutka
Keyword(s):  
World Market ◽  
View Point ◽  
Eu Countries ◽  
Bcg Matrix ◽  
The World ◽  
Comparative Advantages ◽  
Two Stages ◽  
Balassa Index ◽  
The Eu

This paper analyses the commodity structure of Czech (CR) agrarian trade in relation to the EU countries. An emphasis is put on comparative advantages of particular aggregations from the view-point of their application on the EU internal market. This analysis is based on an evaluation of comparative advantages by means of a modified Balassa index. It is studied in two stages, for the internal EU market and the world market. The analysis results are then shown in a graph. Subsequently, the authors implement an idea arising from a BCG matrix on the results of the graphic presentation. The aim is to identify those aggregations (SITC, rev. 3) which are or have a potential to be a pillar of agri-business (ie, the “cash cows” and “stars”), and vice versa to show the aggregation which are non-prospective in the long term or problematic (ie, the “dogs” and “problem children”). As start are identified as those aggregations which are characterised by the highest growth rate of comparative advantage value. From the analysis results, changes are apparent if we compare the CR trade commodity structure in relation to the EU countries. Findings also concern the development of comparative advantages and following CR specialisation on trade with certain aggregations.

scholarly journals Slow-release fertilizers and possibilities of their utilizing in nursery

2004 ◽  
Vol 52 (2) ◽  
pp. 155-164
Author(s):  
Petr Salaš
Keyword(s):  
Slow Release ◽  
Ornamental Plants ◽  
Woody Species ◽  
Soil Surface ◽  
Berberis Thunbergii ◽  
Slow Release Fertilizers ◽  
Picea Omorika ◽  
One Year ◽  
Two Stages

Reserve, slow-release fertilizers (SRF) enable to simplify the whole system of plant nutrition and fertilisation. Tabletted fertilizers of the Silvamix series represent a prospective product of Czech provenience. At our university, these fertilizers have been tested and used since the year 1991. Ornamental woody species grown in containers were investigated in two stages. Experiments with ornamental plants were established using one-year-old cuttings and seedlings of the following deciduous and evergreen woody species:Cotoneaster dammeri Skogholm,Berberis thunbergii,Potentilla fruticosa Snowflake,Ligustrum vulgare AtrovirensandPicea omorika. After planting into containers, fertilizers in the dose of 1 tablet (i.e. 10 g) per litre of substrate were applied either to roots level or on the soil surface in the container. Silvamix in the dose of 5 g.l-1was used as the tested fertilizer in the second stage. It was applied during the planting in the form of tablets and/or a powder. Control plants were fertilized in the course of growing season using a common agricultural fertilizer Cererit Z. The annual plants increments were measured. These experiments demonstrated a long-term optimum effect of this product on woody species and an equal quality and efficiency of its tabletted and powdered forms.

scholarly journals Long-term effects of a chemical decontamination procedure on the corrosion state of the heat exchanger tubes of steam generators

2022 ◽  
Vol 7 (1) ◽  
pp. 77-83
Author(s):  
Andrea Szabó Nagy ◽  
Kálmán Varga ◽  
Bernadett Baja ◽  
Zoltán Németh ◽  
Desző Oravetz ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Heat Exchanger ◽  
Oxide Layer ◽  
In Situ Monitoring ◽  
Ex Situ ◽  
General Corrosion ◽  
Long Term Effects ◽  
Steam Generators ◽  
Corrosion State

Our previous studies have revealed that a ”hybrid” structure of the amorphous and crystalline phases is formed in the outermost surface region of the austenitic stainless steel tubes of steam generators (SGs) as an undesired consequence of the industrial application of the AP-CITROX (AP: alkaline permanganate; CITROX: citric and oxalic acid) decontamination technology. The formation of this mobile oxide-layer increased the amount of the corrosion products in the primary circuit significantly, resulting in magnetite deposition on fuel assemblies. Owing to the fact that there is no investigation method available for the in-situ monitoring of the inner surfaces of heat exchanger tubes, a research project based on sampling as well as on ex-situ electrochemical and surface analytical measurements was elaborated. Within the frame of this project, comprehensive investigation of the general corrosion state and metallographic features of 36 stainless steel specimens, cut out from various locations of the 21 steam generators of the Paks NPP in the time period of 2000-2007 has been performed. The present work gives a brief overview on the general corrosion state of the heat exchanger tubes of SGs, concerning the long-term effects of the AP-CITROX procedure on the chemical composition and structure of the protective oxide-layer.

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