Development of Local Heat Transfer Models for Safety Assessment of Pebble Bed High Temperature Gas-Cooled Reactor Cores

2008 ◽  
Author(s):  
Richard Stainsby ◽  
Matthew Worsley ◽  
Andrew Grief ◽  
Ana Dennier ◽  
Frances Dawson ◽  
...  
Keyword(s):  
Steady State ◽  
Analytical Solution ◽  
Local Heat Transfer ◽  
Research Programme ◽  
Local Heat ◽  
Normal Operation ◽  
Fuel Particle ◽  
Transient Conditions ◽  
Multi Scale ◽  
The Individual

This paper presents a model developed for determining fuel particle and fuel pebble temperatures in normal operation and transient conditions based on multi-scale modelling techniques. This model is qualified by comparison with an analytical solution in a one-dimensional linear steady state test problem. Comparison is made with finite element simulations of an idealised “two-dimensional” pebble in transient conditions and with a steady state analytical solution in a spherical pebble geometry. A method is presented for determining the fuel temperatures in the individual batches of a multi-batch recycle refuelling regime. Implementation of the multi-scale and multibatch fuel models in a whole-core CFD model is discussed together with the future intentions of the research programme.

Development of Local Heat Transfer Models for Safety Assessment of High Temperature Gas-Cooled Reactor Cores—Part I: Pebble Bed Reactors

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Richard Stainsby ◽  
Matthew Worsley ◽  
Andrew Grief ◽  
Frances Dawson ◽  
Mike Davies ◽  
...  
Keyword(s):  
High Temperature ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Normal Operation ◽  
Fuel Particle ◽  
Subsequent Paper ◽  
Pebble Bed ◽  
Transient Conditions ◽  
Pebble Bed Reactors ◽  
Reactor Cores

This and the subsequent paper present models developed for determining fuel particle and fuel element temperatures in normal operation and transient conditions in high temperature reactor cores. Multiscale modeling concepts are used to develop the models for both pebble bed and prismatic core types. This paper, Part I, presents the development of the model for pebble bed reactors. Comparison is made with finite element simulations of an idealized “two-dimensional” pebble in transient conditions, and with a steady-state analytical solution in a spherical pebble geometry. A method is presented for determining the fuel temperatures in the individual batches of a multibatch recycle refuelling regime. Implementation of the multiscale and multibatch fuel models in a whole-core computational fluid dynamics model is discussed together with the future intentions of the research program.

Heat Transfer in Reciprocating Planar Curved Tube With Piston Cooling Application

2005 ◽  
Vol 128 (1) ◽  
pp. 219-229 ◽  
Author(s):  
Shyy Woei Chang ◽  
Yao Zheng
Keyword(s):  
Heat Transfer ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Interactive Effects ◽  
Experimental Conditions ◽  
Nusselt Numbers ◽  
Curved Tube ◽  
The Individual ◽  
Cooling Passage ◽  
Piston Cooling

This paper describes an experimental study of heat transfer in a reciprocating planar curved tube that simulates a cooling passage in piston. The coupled inertial, centrifugal, and reciprocating forces in the reciprocating curved tube interact with buoyancy to exhibit a synergistic effect on heat transfer. For the present experimental conditions, the local Nusselt numbers in the reciprocating curved tube are in the range of 0.6–1.15 times of static tube levels. Without buoyancy interaction, the coupled reciprocating and centrifugal force effect causes the heat transfer to be initially reduced from the static level but recovered when the reciprocating force is further increased. Heat transfer improvement and impediment could be superimposed by the location-dependent buoyancy effect. The empirical heat transfer correlation has been developed to permit the evaluation of the individual and interactive effects of inertial, centrifugal, and reciprocating forces with and without buoyancy interaction on local heat transfer in a reciprocating planar curved tube.

Development of Local Heat Transfer Models for the Safety Assessment of High Temperature Gas-Cooled Reactor Cores—Part II: Prismatic Modular Reactors

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Richard Stainsby ◽  
Matthew Worsley ◽  
Frances Dawson ◽  
Joakim Baker ◽  
Andrew Grief ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Effective Conductivity ◽  
Heat Removal ◽  
Local Heat Transfer ◽  
Multiscale Model ◽  
Local Heat ◽  
Finite Element Simulations ◽  
Normal Operation ◽  
Fuel Elements

This paper extends the work of Part I to be applicable to prismatic block fuel elements and presents a model developed for determining fuel compact and fuel block temperatures of a prismatic core modular reactor. The model is applicable both in normal operation and under fault conditions and is an extension of the multiscale modeling techniques presented in Part I. The new model has been qualified by comparison with finite element simulations for both steady-state and transient conditions. Furthermore, a model for determining the effective conductivity of the block fuel elements—important for heat removal in loss of flow conditions—is presented and, again, qualified by comparison with finite element simulations. A numerical model for predicting conduction heat transfer both within and between block fuel elements has been developed, which, when coupled with the above multiscale model, allows simulations of whole cores to be carried out, while retaining the ability to predict the temperatures of individual coolant channels and individual coated particles in the fuel if required.

A Presentation of Detailed Experimental Data of a Suction Side Film Cooled Turbine Cascade

2000 ◽  
Author(s):  
Holger Brandt ◽  
Wolfgang Ganzert ◽  
Leonhard Fottner
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Gas Turbines ◽  
Measurement Techniques ◽  
Three Dimensional ◽  
Local Heat Transfer ◽  
Suction Side ◽  
Local Heat ◽  
Turbine Cascade ◽  
Shaped Hole

This paper presents detailed isothermal investigations on the aerodynamic effects and the heat transfer of suction side film cooling on a highly loaded turbine cascade. The measurements were carried out with inlet flow conditions kept constant at values which are typically found in modern gas turbines. Five configurations with different hole geometries were investigated, a cylindrical hole with two different streamwise inclination angles, a fan shaped hole and a fan shaped hole with laid-back both only inclined in streamwise direction and a fan shaped hole with laid-back and combined streamwise and lateral inclination. The variation of the blowing ratio enabled closer studies of the mixing process and the influence of the various hole configurations on the aerodynamics and the local heat transfer. To enhance the understanding of the mechanisms and the boundary layer behaviour of these highly three-dimensional flows, much effort has been put on the measurement techniques. The high-resolution data needed was obtained using pressure tappings positioned on the profile, oil-and-dye visualizations on the suction surface, pneumatic probes in the wake and three-dimensional hot wire anemometry in the flow field downstream the holes. Additional heat transfer examinations with a special set-up based on the steady state liquid crystal technique clarified the individual local heat transfer distributions. All measured data are summarized and documented to be used as a reference for three-dimensional, steady-state numerical calculations.

Development of Local Heat Transfer Models for the Safety Assessment of Prismatic Modular High Temperature Gas-Cooled Reactor Cores

2008 ◽  
Author(s):  
Richard Stainsby ◽  
Matthew Worsley ◽  
Frances Dawson ◽  
Joakim Baker ◽  
Andrew Grief ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Effective Conductivity ◽  
Heat Removal ◽  
Finite Element Simulations ◽  
Normal Operation ◽  
Scale Model ◽  
Fuel Particle ◽  
Multi Scale ◽  
Fuel Elements

This paper presents a model developed for determining fuel particle and fuel block temperatures of a prismatic core modular reactor during both normal operation and under fault conditions. The model is based on multi-scale modeling techniques and has been qualified by comparison with finite element simulations for both steady state and transient conditions. Further, a model for determining the effective conductivity of the block fuel elements — important for heat removal in loss of flow conditions — is presented and, again, qualified by comparison with finite element simulations. A numerical model for predicting conduction heat transfer both within and between block fuel elements has been developed which, when coupled with the above multi-scale model, allows simulations of whole cores to be carried out whilst retaining the ability to predict the temperatures of individual coolant channels and individual coated particles in the fuel if required. This ability to resolve heat transfer on length scales ranging from a few meters down to a few microns within the same model is very powerful and allows a complete assessment of the fuel and structural temperatures within a core to be made. More significantly, this level of resolution facilitates interactive coupling with neutronics models to enable the strong temperature/reactivity feedbacks, inherent in such cores, to be resolved correctly.

Sign in / Sign up

Export Citation Format

Share Document