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Unformatted text preview: ENU 4134 Project #2, Fall 2011 – D. Schubring 1 Development & Use of Simple Single-Channel Analysis Code DUE: Part A (November 23, graded in order received, early turn-in advised), Presentations (November 30th and December 2nd), Part B (December 7) ALLOWED COLLABORATION: You may collaborate and divide labor within your group however you choose. One set of deliverables is required per group. No collaboration outside of your group is permitted. 1 Assignment Develop a single-channel analysis code using the numerical method derived/discussed in class, with the following features, in the programming/scripting language of your choice (MATLAB ac- cepted, TK/EES not accepted): • User selectable values: L , L e , D , Pitch , T m,in , ˙ m , P nominal , q max , type of reactor (BWR vs. PWR, for CHF limit applied), D ci , D fo , subcooled boiling flag. These user selectable values should be in a seperate file (an input file) as the main program. • Finite volume size: 400 finite volumes along the axial length. • Power shape: cosine, with extrapolated length. • Evaluation of properties: use the digitized version of T&K’s Table E-1 (on the website) and lineraly interpolate. Note : for density, linearly interpolate the values of specific volume and invert, do not invert these values and interpolate that result. The computed ρ will be different and so will your final answers. • Convection to coolant: use the Weisman correlation for single-phase calculations, with the Schrock and Grossman correlation (based on Weisman’s htc lo ) for two-phase. • Subcooled boiling model: compute x e from an energy balance and use Equation 12-22 in T&K to estimate x . Take Z D as the first location where T co > T sat ( i.e. , neglect the distinctions among bubble departure, boiling incipience, etc.). Use x , not x e , in htc 2 φ , CHF, and dp/dz correlations. When the subcooled boiling model flag is off, x = x e . • CHF: use the correlation of Bowring, adapted by multiplying through by the same ψ as for Weisman. Compute the local CHFR (termed DNBR in a PWR) whenever any vaporization has occurred in the coolant. Alert the user when this is below 1.3 at any point for a PWR and 1.9 at any point for a BWR. • Cladding: assume a constant conductivity k c = 15 W m- 1 K- 1 . • Gap conductance: use Equation 8-107a, with f = c = 1 and δ eff = R ci- R fo . This will require iteration; select an appropriate convergence criterion on T fo . Assume a helium-filled gap. • Fuel conductivity: integrate Equation 8-16a and use a conductivity integral approach. This will require iteration; select an appropriate convergence criterion on T max . • Pressure drop: in each finite volume, estimate this using the Cheng and Todreas equation for single-phase friction (if single-phase) or the HEM model if two-phase. dx/dz comes from the ENU 4134 Project #2, Fall 2011 – D. Schubring 2 energy balance. In two-phase, take Cheng and Todreas for f lo and assume f lo = f TP . This is....
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- Fall '11
- Sans-serif, PWR, D. Schubring