Question

use steam tables from perrys

Problem 3 Using the steam tables: a) Calculate Cp for superheated steam at 200 bar and 450 C. Compare this value to Cp for superheated steam at 450 C and lower pressures. At what point does the assumption Cp Cpis become valid, so that the assumption (H2-HI) = Cpis(T2-TI) is ok to use (assume 5% error is acceptable)? b) Use your best estimate of Cpis for 450 C to estimate H for superheated steam at 5 bar and 500C, and compare your result to that shown in the steam table. What do you conclude from this result?

Answer 1

Ans!! Eiven stream at for Supee heated steam at 200 bar and 450 e. where - The value of Cp : 4.0013 Kalk8k. Compare this value for Cp for Superheated 450 C 150 ba? - 3.268 kJ /kok. 100 bar - 2.949 kJ / kgK. 50 bar - 237 ky lkgk. I bar - 2.101 kilksic. 0.5 bar 2.099, Both are almost fonal so 450 C and lbal assumption , 3) By using Cpu epig Become Valid. stream tables. Super haald Steam is a Steam at higher than its Vapounisation (boiling ) absolute pressure while the temparature is a timparature the Point at mea Su ned, From Steam tabas Stam QC 5 bar and 500C. and Enthalpy : 3484, 41 KJ / Kogor

Now, Enthalpy at 5 bay and 450 = 3311. 669 Kulice Enthalpy at 500, Enthalpy 450 + (p (500-450). : 3377.69 kilks +2.10* (50), 3311.69 kg/Kg + 105.