Thermohydraulic Design of Nuclear Devices 2

Garant předmětu:

Lecturer:

Tutor:

Supervisor:

Department of Nuclear Reactors

Synopsis:

With this course, students are introduced into problem of thermohydraulic calculations. Step by step they will learn more about fluid mechanics and fundamentals of heat transfer. In the fluid mechanics is the most important part dedicated to fundamentals: description of flow, definition of quantities and equations, pressure drops, 1D description of flow, turbulence and its influences on the flow characteristics, boundary layers and centrifugal pumps. That way students obtain knowledge which are necessary for insight into convection as well as into fundamental principles of devices in nuclear power plants. In field of the heat transfer are discussed all types basic modes of heat transfer (conduction, convection a radiation). The lectures are focused to fields which are necessary for designs of nuclear reactors as well as others devices in nuclear power plants.

Requirements:

THN1

Syllabus of lectures:

1. Introduction to fluid mechanics, definition of terms and quantities

Time range: 1 lecture

Introduction to fluid mechanics, definition of basic quantities in fluid mechanics (pressure, velocity field, etc.), description of basic fluid properties (viscosity, surface tension, etc.), Newton?s law, fluid classification according to viscosity.

2. Hydrostatic

Time range: 1 lecture

Hydrostatic pressure, Archimedes principle and floating, force caused on areas in fluid (plane, general), derivation of hydrostatic Euler?s equation and their use: fluids in relative equilibrium, equipotential surfaces.

3. Fluid kinematics

Time range: 1 lecture

Basic terms (flow line, vorticity, vortex line, velocity circulation, etc.) and laws (Helmholtz?s theorem, theorem of Stokes, etc.), derivation of mass conservation equation (equation of continuity), potential flow (definition), complex potential function and its use for calculation, flow around basic shapes.

4. Equations of fluid dynamics

Time range: 2 lectures

Basic definition in fluid dynamics, Euler?s equation of fluid dynamics, Navier-Stokes equations for uncompressible and compressible fluids (derivation, boundary conditions) calculation of basic types of flow, definition of hydraulic diameter.

5. Turbulent flow

Time range: 2 lectures

Definition of turbulent flow and its description according to Euler and Lagrange, methods of description and calculation of turbulent flow: Reynolds equations and their closure, Reynolds tensions, turbulent kinetic energy, basic features of turbulence, Boussinesque hypothesis, turbulent viscosity, influence of turbulence on flow characteristics.

4. Pressure drops

Time range: 2 lectures

Definition of pressure drops, pressure drops on local losses - coefficients of local losses: bends, valves and fittings, restrictions, etc., local losses in nuclear reactors (entrance, exit, spacer grids, ?), friction pressure losses, friction factor and its determination, acceleration pressure loses, televation pressure losses, calculations of pressure drops, use of pressure losses for calculation of velocity profile in circular pipe (power law).

5. 1D flow

Time range: 2 lectures

Derivation of Bernoulli's equation and Euler-Lagrange?s equation, use of equations for 1D flow calculations, loss energy, simplification of selected flows on 1D flow and their solving: outflows, shrouds, Prandtl and Pitott pipes, transient 1D flow, ?

6. Theorem about momentum flow change

Time range: 2 lectures

Derivation of theorem about momentum flow change, use of theorem about momentum flow change for calculations: action of force on channels, walls and curved areas, Pelton bucket, Pelton turbine, jet pumps.

7. Flow of real fluid around surfaces, boundary layer

Time range: 2 lectures

Definition, origin and types of boundary layer, basic features of boundary layer, description and solving of plane boundary layer, flow around curved walls and separation of boundary layer, calculation of forces.

8. Rotating channel

Time range: 2 lectures

Theory of rotating channel, equation of rotating channel, aplocation in vcentrifugasl pump, pumping equipment and specific pump energy, pump characteristics (Q-H characteristic), pump choice for piping.

9. Introduction to heat transfer

Time range: 2 lectures

Basic modes of heat transfer (conduction, convection a radiation) and their short description, examples of application in nuclear devices, conjugate heat transfer, application of conservation of energy principle on checkplots.

10. Conduction

Time range: 5 lectures

Principles of conduction, Fourier law, thermal conductivity (mainly for material used in nuclear reactors, UO2), derivation of Fourier differential equation of heat transfer and their boundary conditions, solving of Fourier differential equation of heat transfer for simple cases of temperature fields and geometries: steady state conduction on wall (plane, cylindrical) without internal heat sources and with internal heat sources in the course of different boundary conditions, 1D conduction in fins and use of fin efficiency, fundamentals of 2D solution of conduction (plane wall, cylindrical wall with boundary condition as function of angle, ...), 1D transient heat transfer.

11. Convection

Time range: 5 lectures

Principles of convection, Newton equation and heat transfer coefficient, theory of similarity and field of its use, important dimensionless numbers and their derivation, determining quantities, single-phase external forced convection: plane wall (laminar, turbulent boundary layer, influence and rise of boundary layer, cross flow around pipe (laminar, turbulent, heat transfer coefficient as function of pipe perimeter), convection on tube bundle; single-phase external natural convection on walls in large space (vertical and horizontal plane walls), single-phase internal forced convection: issue of reference temperatures, inlet area, area of developed flow, laminar, turbulent flow; single-phase internal natural convection; two-phase convection: condensation (theory, film and drop condensation, determination of heat transfer coefficient on pipes and vertical walls), boiling (theory, nucleate boiling, film boiling, boiling crisis of 1st type, boiling crisis of 2nd type, critical heat flux, determination of heat transfer coefficient on pipes and vertical walls).

12. Fundamentals of radiation

Time range: 1 lecture

Principles of radiation, definition of quantities (emittance, emissivity, etc) and terms (black body, etc.), fundamental laws (Kirchhoff's law, Planck law, Wien law, Stefan-Boltzman law, etc.), radiation between parallel plates, radiation of general bodies, radiaton of gases.

13. Heat exchangers

Time range: 1 lecture

Types of heat exchangers (regenerative, counter heat exchanger, etc), temperatures, heat design fundamentals of heat exchangers.

Syllabus of tutorials:

Selected chapters are demonstrated on simple examples (hydrostatic pressure, force caused on areas in fluid, Archimedes principle and floating, complex potential function, Navier-Stokess equation, pressure drops, Bernoulli's equation and Euler-Lagrange?s equation, Theorem about momentum flow change, pumping equipment, heat transmission through wall, fins, temperature field in wall with internal heat source and unsymmetrical boundary conditions 3rd and 4th type, external convection (forced and natural), internal convection, boiling, radiation.

Study Objective:

Knowledge: students will get basic knowledge about field of fluid mechanics and heat transfer, which they can use especially in solving of thermohydraulic of primary circuit and nuclear reactors core. This basic knowledge will allow them to get in detail designs of another devices of the nuclear power plants (for example heat exchangers, steam generators, condensators, pumps, etc.) and they will allow them to understand their operational and physical features.

Abilitiesi: Students will be better orientated in the given problematics and they will be able to work on basic simplified designs. Obtained knowledge will use in the following parts of this course (17THN3) and all consecutive course, which are focused on thermal and hydraulics problematic or designing of single devices in nuclear power plant. On base of given knowledge students will be able to understand and analyse behavior and control of nuclear power plant as a complex.

Study materials:

Key references:

Hejzlar, R.: Fluid mechanics, Vydavatelství ČVUT, Praha, 2001, (in Czech)

Hejzlar, R.: Heat transfer, Vydavatelství ČVUT, Praha, 1999, (in Czech)

Mareš R., Šifner O., Kadrnožka J.: Tables of properties of water and steam somputed from the industrial formulation IAPWS-IF97, VUTIUM , 1999, ISBN 80-214-1316-6

Recommended references:

Incropera, F. P., DeWitt D. P.: Introduction to Heat Transfer, John Willey & Sons, New York, 1996, ISBN 0-471-30458-1

Tong, L.S., Weisman, J.: Thermal Analysis of Pressurized Water Reactors, American Nuclear Society, Illinois USA, 1996, ISBN: 0-89448-038-3

Note:

Further information:

No time-table has been prepared for this course

The course is a part of the following study plans: