Thermodynamics problems with solutions | ENSC 2213, Exams of Thermodynamics

Download Thermodynamics problems with solutions | ENSC 2213 and more Exams Thermodynamics in PDF only on Docsity! ENSC 2213 Thermodynamics PRACTICEE NAME --- _. -:~ p 7;~~o L Q1h.o ~<'Io -----"l> {: vJ. ~ "" t t Qc.'\. ~ -; //// / 1;"Q~<=(-n..•1 )(!)H-, ';~ .~~/)(Soo) ::~0 \tV ::c VI CiI '"' vi::. (., \l <;ool<.j) - I SO - I 1.0 w'1. - 2:'/' - /' ( Q" ,-_::c ~ c_,:) r'l (25) Problem 1 mes operate in series. The first cycle receives energy by heat transfer (QH,I J) from a high temperature reservoir at TH= 727°C and rejects energy (Qe,l) to a reservoir at an intermediate temperature TI = 427°C. The heat rejected from the first cycle (Qe,l) is the heat input to the second cycle (QH,2).The second cycle produces half the work of the first cycle and rejects heat (Qe,2) by heat transfer to a cold temperature reservoir at Te, For these cycles determine: (a) 1'\1,(b) WI (kJ) , (c) QH,2(kJ) , (d) 1'\2,and (e) Te ("C), Answers: (a) 30%, (b) 150 kJ, (c) 350 kJ, (d) 21.4%, (e) 277,2"C ENSC 2213 Thermodynamics PRACTICE EXAM 3 NAME ----------- (25) Problem 2. Carbon dioxide (an ideal gas with variable specific heats) contained in a piston-cylinder assembly undergoes an expansion process from TI = 400°F, VI= 15 fe/lb to T2= 200°F, V2= 25 [(3/Ib. (a) Determine the change in the sRecific entropy of the carbon dioxide (C02) gas between states 1 and 2 (Bfii7ibm~ysing data from ideal gas properties table (Table A-23E). ~ (b) Can this expansion process occur adiabatically? (Justify your answer quantitatively.) Tr ~ fooor =,('i'bO.~ ~~/)% o "S -) -?l I No) 6~ Answers: (a) -1.115 Btu/lbmol.oR, (b) No ~~~~~~~=~===~~~~=================. ============