Reactor Cavity Cooling System Facility Shakedown and RELAP5-3D Model Validation

2012 ◽  
Author(s):  
R. Vaghetto ◽  
Saya Lee ◽  
Y. A. Hassan
Keyword(s):  
Steady State ◽  
3D Model ◽  
Cooling System ◽  
Coolant Flow ◽  
Experimental Results ◽  
Normal Operation ◽  
Small Scale ◽  
Water Tank ◽  
Experimental Facility ◽  
Cavity Cooling

A small scale water-cooled experimental facility was built in order to study the complex thermohydraulic phenomena taking place in the Reactor Cavity Cooling System (RCCS) during the normal operation (steady-state case) an during accident scenario when forced convection is lost. The facility represents a portion of the reactor vessel with nine stainless steel coolant risers. The pipes are connected via cold and hot manifolds to a water tank located on top of the cavity. Due to the complexity of the expected thermal hydraulic phenomena, a RELAP5-3D input deck was prepared in order to predict the main thermohydraulic parameters, mainly coolant flow rate and temperatures. During the facility shakedown, the coolant flow was constantly monitored in order to observe the natural circulation startup phase and some interesting features of the coolant behavior were observed. The comparison of the preliminary experimental results from a test run with the prediction of the RELAP5-3D simulations helped validating the assumptions and simplifications adopted in the model for future simulations of steady-state and transients, and confirmed the potentiality of the system code for analysis of such systems. In the present paperwork, a detailed description of the experimental facility and the RELAP5-3D model are provided. Preliminary experimental results from different test runs are described and compared with the RELAP5-3D simulation results.

scholarly journals EXPERIMENTAL ANALYSIS OF THE TRANSIENT BEHAVIOR OF AN ENGINE COOLING RADIATOR

2018 ◽  
Vol 17 (2) ◽  
pp. 16
Author(s):  
K. Rodrigues ◽  
J. P. S. Ieno ◽  
L. F. Novazzi ◽  
C. Albuquerque
Keyword(s):  
Steady State ◽  
Cooling System ◽  
Transient State ◽  
Transient Behavior ◽  
Water Tank ◽  
Thermal Camera ◽  
Transient Conditions ◽  
Small Water ◽  
Engine Cooling ◽  
Experimental Apparatus

The aim of this work is to study the behavior of an engine cooling radiator in a transient state, with circulation of heated water. An experimental apparatus was constructed with the radiator inside a wind tunnel. The water is pumped from a small water tank to a heater, passes through the heat exchanger, and returns to the tank. The tests were carried out with constant flowrates of water and air, and the heater was turned on and then off according to a pulse function. The temperatures of the radiator, the air and the water were measured on several points with thermocouples and a thermal camera. The flow of water and air were measured as well. A fast dynamics because of the radiator was observed, whereas a slow one was noticed due to water heating in the tank. The steady state was reached after 15 min. These results might be useful in the project of a vehicle cooling system under transient conditions.

Experimental and numerical study of friction and .giffness characteristics of small rolling tires

2011 ◽  
Vol 39 (1) ◽  
pp. 5-19 ◽  
Author(s):  
R. van der Steen ◽  
I. Lopez ◽  
H. Nijmeijer
Keyword(s):  
Steady State ◽  
Numerical Study ◽  
Complex Structure ◽  
Element Model ◽  
Steady State Solution ◽  
Experimental Results ◽  
Small Scale ◽  
The Road ◽  
Rubber Compounds ◽  
Complex Measurement

Abstract Virtual testing is nowadays the standard in the design process of new tires. Besides modeling the static response of the tire itself, the dynamics of a rolling tire in contact with the road needs to be incorporated. Due to the uncontrollable environmental conditions and the complex structure of the tires, it is advantageous to use small-scale testing under more controlled conditions. Experimental characterization of frictional properties of rubber compounds is, however, limited due to the necessity of complex measurement systems. In this paper a commercially available laboratory abrasion and skid tester is used to ide.gify both friction and .giffness characteristics of the same rubber compound. The obtained friction properties are implemented in a finite element model of the setup, and different validation steps are presented. Finally, a steady-state transport approach is used to efficiently compute a steady-state solution, which is compared with the experimental results. The numerical results show a good qualitative agreement with the experimental results.

scholarly journals Experimental investigation of thermoelectric cooling system with heat recovery

2019 ◽  
Vol 100 ◽  
pp. 00020 ◽  
Author(s):  
Justyna Gołębiowska ◽  
Agnieszka Żelazna
Keyword(s):  
Water Temperature ◽  
Heat Recovery ◽  
Cooling System ◽  
Small Scale ◽  
Water Tank ◽  
Thermoelectric Cooling ◽  
Experimental Room ◽  
Domestic Water ◽  
Power Generators ◽  
Cooling Effects

Thermoelectric modules are implements used as power generators and cooling devices. In case of TE module application for space cooling, it is highly recommended to reuse energy generated on the hot side of the module for example for domestic water heating. In this paper, an example of a small scale thermoelectric cooling system with heat recovery was presented. In the tested system, the performance of TE module was supported by two heat exchangers. On the cold side of the TE module the forced convection was provided by the implementation of aluminium heat sink integrated with fan. On the hot side a water heat exchanger was built in order to reuse waste energy to heat water in the water tank. Different values of current were applied to the TE module to observe the differences in the module performance. The correlation between the air temperature inside the experimental room and the water temperature in the tank were determined for all conducted series. In general, the best cooling effects were achieved when the water temperature in the tank was not higher than 26.4°C. The maximum reduction of temperature inside the experimental room was noted for the amperage 7 A and it was 11.7°C.

scholarly journals REACTOR CAVITY COOLING SYSTEM WITH PASSIVE SAFETY FEATURES ON RDE: THERMAL ANALYSIS DURING ACCIDENT

2019 ◽  
Vol 21 (2) ◽  
pp. 87
Author(s):  
Rahayu Kusumastuti ◽  
Sriyono Sriyono ◽  
Mulya Juarsa ◽  
Hendro Tjahjono ◽  
I. D. Irianto ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Natural Convection ◽  
Cooling System ◽  
Power Level ◽  
Heat Removal ◽  
Reactor Vessel ◽  
Normal Operation ◽  
Passive Safety ◽  
Diesel Generator ◽  
Cavity Cooling

Reaktor Daya Eksperimental (RDE) is an experimental power reactor based on HTGR technology that implements inherent safety system. Its safety systems are in compliance with “defense in depth” philosophy. RDE is also equipped with reactor cavity cooling system (RCCS) used to remove the heat transferred from the reactor vessel to the containment structure. The RCCS is designed to fulfil this role by maintain the reactor vessel under the maximum allowable temperature during normal operation and protecting the containment structure in the event of failure of all passive cooling systems. The performance and reliability of the RCCS, therefore, are considered as critical factors in determining maximum design power level related to heat removal. RCCS for RDE will use a novel shape to efficiently remove the heat released from the RPV through thermal radiation and natural convection. This paper discusses the calculation of RCCS thermal analysis during accident. The RPV temperature must be maintained below 65ºC. The accident is assumed that there is no electricity from diesel generator supplied to the blower. The methodology used is based on the calculation of mathematical model of the RCCS in the passive mode. The heat is released through cavity by natural convection, in which the RCCS is capable to withdraw the heat at the rate of 50.54 kW per hour.Keywords: Passive safety, RCCS, RDE, Thermal analysis

Experimental Investigation of Reactor Cavity Cooling System (RCCS) for a Very High Temperature Reactor (VHTR)

2010 ◽  
Author(s):  
L. Capone ◽  
C. E. Perez ◽  
Y. Hassan
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Surface Temperature ◽  
Temperature Profile ◽  
Cooling System ◽  
Experimental Facility ◽  
Very High Temperature Reactor ◽  
High Temperature Reactor ◽  
Cavity Cooling ◽  
Very High

The reactor cavity cooling system (RCCS) for a very high temperature reactor (VHTR) represents a very important safety feature for achieving the defense in depth of the plant. An experimental facility was built for testing the heat transfer capability and phenomenology of this last heat sink designed for ensuring the cooling down of structural material of the vessel and of the concrete walls of the vessel cavity. This small scale facility was built using some of the scaling laws in order to resemble the main heat transport features in RCCS configuration. The natural convection phenomena and radiative heat transfer inside the cavity were represented. The experimental facility represents half of the vessel and of the reactor cavity with five stand pipes for cavity cooling using water as cooling fluid. Measurements were performed heating up the vessel surface temperature to an average temperature of 300 °C that is the average value in accident scenarios. Temperature measurements of the vessel surface temperature, the outer pipes surface temperature profile and inlet and outlet temperature of the cooling water were performed. Axial and radial temperature profiles of the air in the cavity were measured using a movable rack of 24 thermocouples. The results demonstrated the natural circulation phenomena. In addition Velocity measurement of the air inside the cavity were performed using particle tracking velocimetry techniques (PTV) determining the flow regime characteristics and the coupling with the temperature profile. The experimental test matrix of various flow rates in the cooling pipes were carried out.

Holdup and holdup profiles in the reciprocating plate extractor VPE

1990 ◽  
Vol 55 (11) ◽  
pp. 2648-2661 ◽  
Author(s):  
Helena Sovová ◽  
Vladislav Bízek ◽  
Jaroslav Procházka
Keyword(s):  
Steady State ◽  
Experimental Results ◽  
Model Parameters ◽  
Dispersed Phase ◽  
Pulse Form ◽  
Sieve Plates

In this work measurements of mean holdup of dispersed phase, of axial holdup profiles and of flooding points in a reciprocating plate contactor with both the VPE-type plates and the sieve plates were carried out. The experimental results were compared with a monodisperse model of steady-state column hydrodynamics and the model parameters were evaluated. Important differences in the behaviour of the two plate types could be identified. Comparison was also made between two reciprocating drives of different pulse form.

scholarly journals Development and Evaluation of an Ultrasonic Humidifier to Control Humidity in a Cold Storage Room for Postharvest Quality Management of Dates

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 949
Author(s):  
Maged Mohammed ◽  
Nashi Alqahtani ◽  
Hamadttu El-Shafie
Keyword(s):  
Quality Management ◽  
Cold Storage ◽  
Cooling System ◽  
Positive Impact ◽  
Droplet Diameter ◽  
Postharvest Quality ◽  
Main Element ◽  
Small Scale ◽  
Storage Room ◽  
Ultrasonic Humidifier

Dates are subjected to postharvest losses in quality and quantity caused by water loss, fermentation, insect infestation, and microbial spoilage during storage. Cold storage is the main element in the postharvest quality management used for fruit preservation. Although cold storage is used for dates, precision control of the relative humidity (RH) using ultrasonic applications is not used thus far, or it is applied to other fruits on a small scale. Therefore, we designed and constructed an ultrasonic humidifier (DUH) for RH control in the cold storage room (CSR) of dates. The optimum air velocity of 3 m s−1 at the outlets of the DUH ducts produced a mist amount of 6.8 kg h-1 with an average droplet diameter of 4.26 ± 1.43 µm at the applied voltage of 48 V and frequency of 2600 kHz of the transducers. The experimental validation was carried out by comparing a CSR controlled with the DUH with two conventional CSRs. The three tested CSRs were similar in dimensions, cooling system, and amount of stored dates. The time required for cooling 800 kg of dates in the controlled CSR from 25 °C to the target temperature of 5 °C was approximately 48 h. The DUH precisely controlled the RH at the maximum RH set point of 80% in the tested CSR at 5 °C. The controlled RH at 80% has a positive impact on the physicochemical characteristics of the stored dates. It significantly reduced the weight loss of the fruits and preserved fruit mass, moisture content, water activity, firmness, and color parameters. However, no significant effect was observed on fruit dimensions, sphericity, and aspect ratio. The microbial loads of mesophilic aerobic bacteria, molds, and yeasts fell within the acceptable limits in all tested CSRs. Both stored date fruits and artificially infested dates showed no signs of insect activity in the controlled CSR at the temperature of 5 °C and RH of 80%. The DUH proved to be a promising technology for postharvest quality management for dates during cold storage.

Wave Energy Hyperbaric Device for Electricity Production

2007 ◽  
Author(s):  
Segen F. Estefen ◽  
Paulo Roberto da Costa ◽  
Eliab Ricarte ◽  
Marcelo M. Pinheiro
Keyword(s):  
Power Generation ◽  
Wave Energy ◽  
Experimental Results ◽  
Electricity Production ◽  
Scale Model ◽  
Small Scale ◽  
Regular Waves ◽  
Hyperbaric Chamber ◽  
Small Scale Model

Wave energy is a renewable and non-polluting source and its use is being studied in different countries. The paper presents an overview on the harnessing of energy from waves and the activities associated with setting up a plant for extracting energy from waves in Port of Pecem, on the coast of Ceara State, Brazil. The technology employed is based on storing water under pressure in a hyperbaric chamber, from which a controlled jet of water drives a standard turbine. The wave resource at the proposed location is presented in terms of statistics data obtained from previous monitoring. The device components are described and small scale model tested under regular waves representatives of the installation region. Based on the experimental results values of prescribed pressures are identified in order to optimize the power generation.

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