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Critical Heat Flux 02 1A boiling channel has operating characteristics listed below. Assuming the heat flux profile is ⎟⎠⎞⎜⎝⎛′′=′′Hzqzqπsin)(0Determine the critical power ratio in the channel using both the Hench-Levy and CISE-4 correlations. You may assume for the Hench-Levy correlation, that the critical power corresponds to the condition where the minimum critical heat flux ratio is one. The CISE-4 critical boiling length correlation is ⎟⎟⎠⎞⎜⎜⎝⎛+=bLaLDDxcritcritehcritwhere hDis the heated diameter and eDis the equivalent diameter for the channel. The parameters in the CISE correlation are: ⎪⎪⎩⎪⎪⎨⎧−×>−−×≤−×+=−−33/1334)/1(3375)1000/(/1)/1(3375)/1(10481.111ccccPPGGPPPPGGPPa4.14.0)1/(199.0GDPPbc−×=G = kg/m2-s D = m P = MPa Pc= Critical Pressure (Mpa) Lcrit= m Problem DataMaximum Heat Flux 354,000 Btu/hr-ft2Channel Mass Flux 1.13 x 106lbm/hr-ft2Rod Pitch 0.640 inches Rod Diameter 0.493 inches Channel Pressure 1000 psia Channel Height 148 inches Inlet Temperature 532 F SOLUTION The critical power ratio for the channel is
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