HW6PWR - Operating parameters for a PWR hot channel is...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Operating parameters for a PWR hot channel is given below. Compute and plot the mixture and phase velocity distributions. Determine the individual components of and the total pressure drop. Compare the results obtained using both equilibrium and non equilibrium models. You may assume the saturation properties are constant along the length of the channel and may be evaluated at the system pressure. PRESSURIZED WATER REACTOR PARAMETERS Pressure 2250 psia Coolant Mass Flux 2.50 x 10 6 lbm/hr-ft 2 Core Inlet Temperature 545 F Maximum Core Heat Flux 580,000 Btu/hr-ft 2 Rod Pitch 0.563 inches Rod Diameter 0.422 inches Fuel Height 144 inches Upper and Lower Tie Plate Loss Coefficient 3.5 Grid Loss Coefficient 0.5 Number of Grids/assembly 8 Axial Peak to Average Ratio 1.5 The axial heat flux may be taken to be ′′ + qz q z H e () s in = 0 πλ You may assume the two-phase friction multiplier is given by the expression 75 . 1 2 2 ) 1 ( 1 20 1 x o + + = χ φ A where is the turbulent Martinelli parameter and given by μ ρ 2 02 18 1 = f g g f x x . . and that the Homogeneous Multiplier derived in class is valid for the local losses.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
SOLUTION Heat Flux Profile The heat flux profile is given as ′′ + qz q z H e () s in = 0 πλ where for this profile the maximum heat flux occurs at 2 / H and is equal to 0 q . For the hot channel, then 2 0m a x 580,000 Btu/hr-ft qq == . Extrapolation Distance The axial peak to average ratio is defined to be q z q F z ) ( max where max z is the position of maximum heat flux in a particular channel, and q is the axially averaged heat flux in the same channel. Note, that since for any given channel ) ( max z q and q both contain the amplitude 0 q , this parameter cancels and the axial peak to average ratio is only a function of shape. The position of maximum heat flux is that location such that 0 max = z q dz d For this heat flux profile, the maximum heat flux occurs at 2 H , such that a x m a x ( ) 580,000 z q = Btu/hr-ft 2 . The axially averaged heat flux is defined to be dz H z q H dz z q H q e H H + = λ π 0 0 0 sin 1 ) ( 1 + = e e e H H H H H q q ) ( cos cos 0 The axial peaking factor is then + = e e e z H H H H H F ) ( cos cos
Background image of page 2
For λ 2 + H H e , this expression is transcendental in and must be solved iteratively. Iterating on gives feet. 3009 . 0 = Enthalpy Distributions The enthalpy distribution is given by the simple energy balance hz h m qz D d z z () ±
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 12/08/2010 for the course NE 402 taught by Professor Doster during the Fall '08 term at N.C. State.

Page1 / 12

HW6PWR - Operating parameters for a PWR hot channel is...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online