Question

Example 5 Helium is expanded in a turbine from 1500 kPa and 300°C to 100 kPa and 25°C. Determine the maximum work this turbine can produce, in kJ/kg. Does the maximum work require an adiabatic turbine?

Answer 1

Given dato: pressure at turbine inlet CP, 2= 1500 kPa ; Temperature at turbine inlet CTD: 900 € = (300ta7k-573k; Pepsoy&e cut tebine eretlet (23) = 100 kPa ģ Temperature at turbine outlet (12)=250=45+273)ķ5298k Specific heat at constant pressure of thelirim (Cp) ce = 5.19 KILRgK land adiabatic of isentropic inder c)1.667 for helium. Hest eve As we will call create wolk ortpret turbine for giren expansion process celelalt knew that, W, = mCp (Ti-To) = (1) (5-19 x103) C 573-298) Wie 1427.25 KJ/Kg. & Need we calcrelate temperature after expansion if it were adiabatic expansion. As we know that TL T2 Pe (1-5.667 쯤 - Tiz PR 100203 ps 1500x109 male Charles T.667 (573).

6. T2 = 193. 899k. As line will calculate walk output of turbine it process or expansion were adiabatic Chad eve knew that, -W = m Cp CT-T:) = C12C5-19 X103) (573- 193,899) 12 = 1986.294 kJ/kg. Therefore we can say that, and thee to that, maximum edock equices e adiabatic turbine. لاحولها en
Here, it is obvious that work output of turbine is greater in case of adiabatic expansion therefore it is necessary to require adiabatic expansion for maximum work output