06 btulbm 003607 btulbm r 11623 btulbm 17405 btulbm

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: balances gives · Q out · m 1h1 · m 2h2 · (m 1 · m 2)h3 The desired properties at the specified states are determined from the steam tables to be State 1: P1 T1 20 psia 50°F h1˘hf @ 50°F s1˘ sf @ 50°F State 2: P2 T2 20 psia 240°F h2 s2 State 3: P3 T3 20 psia 130°F h3˘hf @ 130°F s3˘ sf @ 130°F 18.06 Btu/lbm 0.03607 Btu/lbm · R 1162.3 Btu/lbm 1.7405 Btu/lbm · R 97.98 Btu/lbm 0.18172 Btu/lbm · R Substituting, 180 Btu/min [300 18.06 · m2 1162.3 (300 · m 2) 97.98] Btu/min cen54261_ch07.qxd 11/18/03 9:57 AM Page 329 329 CHAPTER 7 which gives · m2 22.7 kg/min The rate of entropy generation during this process can be determined by applying the rate form of the entropy balance on an extended system that includes the mixing chamber and its immediate surroundings so that the boundary temperature of the extended system is 70°F 530 R: · →0 (steady) ∆Ssystem 14 424 43 · · Sin Sout 14243 · Sgen 123 Rate of net entropy transfer by heat and mass Rate of entropy generation · m 1s1 · m 2s2 · m 3s3 Ra...
View Full Document

This document was uploaded on 11/28/2012.

Ask a homework question - tutors are online