22.06 ENGINEERING OF NUCLEAR SYSTEMS - Fall 2010 Problem Set 6 Pure Substance Model and Two-Phase Flow Basics 1) Using the steam tables (or the phase diagram of water), identify the phases corresponding to the following P-T combinations: a) P=1.0 MPa, T=150C b) P=9.0 MPa, T=320C c) P=0.1 MPa, T=-10C Same as above for the following P-h combinations: d) P=9.0 MPa, h=1500 kJ/kg e) P=7.0 MPa, h=2100 kJ/kg f) P=7.0 MPa, h=3000 kJ/kg - Determine the temperature and quality (x) for states d and e. - Put states a, b, d, e and f on a qualitative T-s diagram (show the isobar line for each state). 2) The coolant density in a BWR fuel assembly must be kept reasonably high to ensure sufficient neutron moderation. Assuming a minimum required coolant (mixture) density m=200 kg/m3, determine the maximum acceptable void fraction and flow quality in the BWR fuel assembly. Assume S=2; the BWR operating pressure is 7.0 MPa. 3) In a BWR fuel assembly the flow quality ranges from zero (no steam) at the inlet to x0.13 at the outlet. Using the two-phase flow map in Figure 1 below, determine the flow regime at the following values of the flow quality, x=0.01, x=0.03 and x=0.10 (corresponding to various intermediate axial locations within the fuel assemblies). The coolant mass flow rate in the fuel assembly is m =16 kg/s; the fuel assembly flow area is A=91 cm2. The BWR operating pressure is 7.0 MPa. 4) Consider the flow of a liquid-vapor mixture in a vertical channel. Using your physical intuition, determine whether S>1, S1 or S<1 for each of the following flow regimes: - Bubbly flow (upward) - Bubbly flow (downward) - Dispersed bubbly flow (upward) - Dispersed bubbly flow (downward) - Plug flow (upward) - Annular flow (upward)- Mist flow (upward) - Mist flow (downward) 10510410310210110-1106105104103102101[xG]2/ρg (kg/s2-m)[(1-x)G]2/ρf (kg/s2-m)AnnularWispy-annularBubblyBubblesslugsSlugsChurnImage by MIT OpenCourseWare.MIT OpenCourseWarehttp://ocw.mit.edu 22.06 Engineering of Nuclear Systems Fall 2010 For information about citing these materials or our Terms of Use, visit: