Development and Processing of Thermal-Hydraulic Model for GFR 2400 Fast Reactor Design and NESTLE Coupled Transient Code

2021 ◽  
Author(s):  
Filip Osuský ◽  
Branislav Vrban ◽  
Stefan Cerba ◽  
Jakub Luley ◽  
Vladimir Necas
Keyword(s):  
Steady State ◽  
Fast Reactor ◽  
Transient State ◽  
Reactor Design ◽  
Temperature Dependent ◽  
Control Rod ◽  
Fuel Bundle ◽  
Fuel Pin ◽  
Radial Heat ◽  
Steady State Heat

Abstract The paper investigates the influence of the used thermal-hydraulic approximations on the coupled calculations of Gas-cooled Fast Reactor design (hereby GFR 2400). The NESTLE code is used as coupled simulation tool and solves the multigroup neutron diffusion equation by the finite difference method that is internally coupled with a thermal-hydraulic sub-channel code. The in-house developed TEMPIN code and the CFD code FLUENT (from ANSYS code system) are used to prepare the thermal-hydraulic data for the GFR 2400 calculations. The TEMPIN code solves the steady state heat balance equation with flowing coolant in triangular lattice cell together with temperature dependent thermal-hydraulic properties of the fuel, cladding and coolant. Based on the calculated fuel bundle temperature distributions by the TEMPIN code, the thermal-hydraulic material properties (approximations) suitable for the NESTLE coupled code are processed for the GFR 2400 design. The influence of the constant and radial heat generation term within the fuel pin is studied within the paper. The performance of the NESTLE code with thermal-hydraulic approximations processed by both (TEMPIN and FLUENT) methods are compared with the findings of the GoFastR project. Moreover, both the thermal-hydraulic approximations were compared for one steady state and one transient state, related to the rapid withdrawal of one control rod assembly from the core. Changes in thermal-hydraulic distributions are described and visualized in the paper.

scholarly journals CFD Analysis of the Primary Cooling System for the Small Modular Natural Circulation Lead Cooled Fast Reactor SNRLFR-100

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Pengcheng Zhao ◽  
Kangli Shi ◽  
Shuzhou Li ◽  
Jingchao Feng ◽  
Hongli Chen
Keyword(s):  
Steady State ◽  
Fast Reactor ◽  
Cooling System ◽  
Natural Circulation ◽  
Reactor Core ◽  
Transient State ◽  
Fuel Pin ◽  
Gen Iv ◽  
Steady State Simulation ◽  
Accident Conditions

Small modular reactor (SMR) has drawn wide attention in the past decades, and Lead cooled fast reactor (LFR) is one of the most promising advanced reactors which are able to meet the safety economic goals of Gen-IV nuclear energy systems. A small modular natural circulation lead cooled fast reactor-100 MWth (SNRLFR-100) is being developed by University of Science and Technology of China (USTC). In the present work, a 3D CFD model, primary heat exchanger model, fuel pin model, and point kinetic model were established based on some reasonable simplifications and assumptions, the steady-state natural circulation characteristics of SNCLFR-100 primary cooling system were discussed and illustrated, and some reasonable suggestions were proposed for the reactor’s thermal-hydraulic and structural design. Moreover, in order to have a first evaluation of the system behavior in accident conditions, an unprotected loss of heat sink (ULOHS) transient simulation at beginning of the reactor cycle (BOC) has been analyzed and discussed based on the steady-state simulation results. The key temperatures of the reactor core are all under the safety limits at transient state; the reactor has excellent thermal-hydraulic performance.

scholarly journals STEADY-STATE HEAT TRANSFER IN A PLATE WITH TEMPERATURE-DEPENDENT THERMAL CONDUCTIVITY (AN EXACT SOLUTION)

2019 ◽  
Vol 18 (2) ◽  
pp. 85
Author(s):  
A. Miguelis ◽  
R. Pazetto ◽  
R. M. S. Gama
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Steady State ◽  
Transfer Problem ◽  
Internal Heat ◽  
Temperature Dependent ◽  
State Heat ◽  
Kirchhoff Transformation ◽  
Steady State Heat ◽  
Steady State Heat Transfer

This work presents the solution of the steady-state heat transfer problem in a rectangular plate with an internal heat source in a context in which the thermal conductivity depends on the local temperature. This generalization of one of the most classical heat transfer problems is carried out with the aid of the Kirchhoff transformation and employs only well known tools, as the superposition of solutions and the Fourier series. The obtained results illustrate how the usual procedures may be extended for solving more realistic physical problems (since the thermal conductivity of any material is temperature-dependent). A general formula for evaluating the Kirchhoff transformation as well as its inverse is presented too. This work has a strong didactical contribution since such analytical solutions are not found in any classical heat transfer book. In addition, the main idea can be used in a lot of similar problems.

Determining Temperature Regulating Factor for Refrigeration Engineering Phase Change Material

2014 ◽  
Vol 521 ◽  
pp. 605-608
Author(s):  
Jia Zheng ◽  
Jie Li ◽  
Xiang Yi Guan ◽  
Shuang Han ◽  
Yi Ming Zhang
Keyword(s):  
Steady State ◽  
Phase Change ◽  
Phase Change Material ◽  
Transient State ◽  
Clothing Industry ◽  
Flux Variation ◽  
Test Instrument ◽  
Steady State Heat ◽  
Comfort Parameters ◽  
Change Material

In order to characterize the temperature regulating ability of fabrics containing phase change material (PCM), the test has been designed. To assess temperature regulating ability, temperature regulating factor (TRF) is determined. TRF is defined as a quotient of the amplitude of the temperature variation of the hot plate and the amplitude of the heat flux variation divided by the steady state heat resistance of the fabric. The test instrument presented here is intended to be used for testing steady state and transient state characteristics of the apparel fabrics containing the PCMs. This test instrument can be used in quality control during the manufacture of fabrics containing PCMs. TRF can be used in clothing industry to establish the criteria for comfort parameters of textiles.

scholarly journals A Linear Approach Suitable for a Class of Steady-State Heat Transfer Problems with Temperature-Dependent Thermal Conductivity

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
R. M. S. Gama ◽  
R. Pazetto
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Steady State ◽  
Robin Boundary Conditions ◽  
Temperature Dependent ◽  
Steady State Heat ◽  
Steady State Heat Transfer ◽  
Transfer Problems ◽  
Robin Boundary ◽  
Temperature Dependent Thermal Conductivity

This work presents an useful tool for constructing the solution of steady-state heat transfer problems, with temperature-dependent thermal conductivity, by means of the solution of Poisson equations. Specifically, it will be presented a procedure for constructing the solution of a nonlinear second-order partial differential equation, subjected to Robin boundary conditions, by means of a sequence whose elements are obtained from the solution of very simple linear partial differential equations, also subjected to Robin boundary conditions. In addition, an a priori upper bound estimate for the solution is presented too. Some examples, involving temperature-dependent thermal conductivity, are presented, illustrating the use of numerical approximations.

Fast Reactor Design Using the Advanced Reactor Modeling Interface

2013 ◽  
Author(s):  
Jesse Cheatham ◽  
Bao Truong ◽  
Nicholas Touran ◽  
Ryan Latta ◽  
Mark Reed ◽  
...  
Keyword(s):  
Steady State ◽  
Fast Reactor ◽  
System Analysis ◽  
Reactor Design ◽  
Modeling Framework ◽  
Reactor Modeling ◽  
Reconstruction Methods ◽  
Single User ◽  
The Impact ◽  
Multi Disciplinary Team

The Advanced Reactor Modeling Interface (ARMI) code system has been developed at TerraPower to enable rapid and robust core design. ARMI is a modular modeling framework that loosely couples nuclear reactor simulations to provide high-fidelity system analysis in a highly automated fashion. Using a unified description of the reactor as input, a wide variety of independent modules run sequentially within ARMI. Some directly calculate results, while others write inputs for external simulation tools, execute them, and then process the results and update the state of the ARMI model. By using a standardized framework, a single design change, such as the modification of the fuel pin diameter, is seamlessly translated to every module involved in the full analysis; bypassing error-prone multi-analyst, multi-code approaches. Incorporating global flux and depletion solvers, subchannel thermal-hydraulics codes, pin-level power and flux reconstruction methods, detailed fuel cycle and history tracking systems, finite element-based fuel performance coupling, reactivity coefficient generation, SASSYS-1/SAS4A transient modeling, control rod worth routines, and multi-objective optimization engines, ARMI allows “one click” steady-state and transient assessments throughout the reactor lifetime by a single user. This capability allows a user to work on the full-system design iterations required for reactor performance optimizations that has traditionally required the close attention of a multi-disciplinary team. Through the ARMI framework, a single user can quickly explore a design concept and then consult the multi-disciplinary team for model validation and design improvements. This system is in full production use for reactor design at TerraPower, and some of its capabilities are demonstrated in this paper by looking at how design perturbations in fast reactor core assemblies affect steady-state performance at equilibrium as well as transient performance. Additionally, the pin-power profile is examined in the high flux gradient portion of the core to show the impact of the perturbations on pin peaking factors.

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