CHBE 244: Chemical and Biological Engineering Thermodynamics I Tutorial 4: Thermodynamics of Processes March 2024 Instructions: Have with you a copy of the STEAM TABLES 1. Rankine Cycle with Reheat: A steam power plant operates on the Rankine cycle with reheat, using the specified conditions below. Using stream numbering from Fig. 5.3, for each of the options below, determine: (a) The work output of each turbine per kg of steam; (b) The work input of the feed water pump per kg of circulated water; (c) The feedrate of steam required; (d) The heat input required in the boiler/superheater and reheater; (e) The thermal efficiency T 8 7 3 5 2 1 4' 4 6' 6 S 8 3 Boiler/ Superheater Pump Condenser 7 6 I 4 Reheater 5 II Figure 5.3 Rankine cycle with reheat. T3(c) P3(MPa) P_(MPa) T3(C) P6(MPa) n turbines "pump Plant efficiency 600 4 1.2 600 0.01 0.85 0.8 80MW
2. Ordinary Vapor Compression: An ordinary vapor compression refrigerator is to operate on refrigerant R134a (properties are given in the form of chart and Table) with evaporator and condenser temperatures at -20? and 35ºC. Assume the compressor is reversible. (a) Make a table summarizing the nature (e.g. saturated, superheated, temperature, pressure and H) of each point in the process. (b) Compute the coefficient of performance for this cycle and compare it to the Carnot cycle value. Hot Side, QH 4 3 Condenser T 4 Throttle Valve Compressor Evaporator 1 Cold Side, Qc 1 2 3 3' I 2 S Properties of Saturated HFC-134a. T P K MPa 240 0.07248 244 0.08784 1385.8 4.5965 248 0.10568 1373.8 5.4707 166.99 252 0.12627 1361.7 6.4715 172.14 385.84 256 0.14989 260 0.17684 1337.0 8.9051 182.55 264 0.20742 1324.4 10.3660 187.81 393.17 0.9548 1.7327 268 0.24197 1311.6 272 0.28080 1298.5 13.8570 198.45 397.93 0.9943 1.7277 276 0.32426 1285.3 280 0.37271 1271.7 18.2270 209.26 402.54 1.0332 1.7235 284 0.42651 1258.0 20.7940 214.74 404.79 288 0.48603 1243.9 23.6450 220.27 406.99 1.0717 292 0.55165 1229.5 26.8080 225.85 409.14 1.0907 1.7184 296 0.62378 1214.7 30.3130 231.49 411.23 300 304 0.70282 0.78918 1184.1 38.4830 242.95 415.22 308 0.88330 1168.1 312 0.98560 316 1.09650 320 1.21660 324 1.34620 328 1.48600 1079.0 75.7890 279.23 332 1.63640 1058.8 84.6440 285.63 336 1.79810 1037.5 94.5630 340 1.97150 1015.0 PL kg/m3 1397.7 3.8367 1349.5 7.6117 177.33 1199.6 34.1920 237.18 413.26 1151.5 1134.5 54.2820 260.68 420.63 1.2038 1116.7 60.7140 266.76 1098.3 67.8510 pv kg/m3 12.0110 193.11 395.56 0.9747 1.7301 15.9230 203.84 43.2280 248.78 417.11 48.4750 254.69 418.92 HL KJ/kg 156.78 161.87 272.94 423.74 292.18 105.7300 298.88 428.17 HV KJ/kg 378.33 380.85 383.35 388.31 390.75 400.25 1.0139 422.25 1.2226 425.10 1.2603 1.7050 426.31 427.34 SL KJ/kg-K 0.8320 0.8530 0.8738 0.8943 0.9147 0.9348 1.7356 1.0525 1.7217 1.1097 1.7169 1.1286 1.7155 1.1475 1.7142 1.1663 1.1850 1.2414 1.7068 1.2793 1.7030 1.2984 1.7007 1.3177 1.6980 KJ/kg-K 1.7552 1.7505 1.7462 1.7423 1.7388 1.7255 1.7200 1.7128 1.7114 1.7100 1.7085
100 20. HFC-134a (1,1,1,2-tetrafluordethana) 200 300 1200. 350 400 450 600 500 550 600 200. p = 500. kg/m 10. reference