Question

5: Calculate the work produced by the following processes of ideal gas with the mass 11 kg, the pressure PI=750 kPa, the specific volume v1=0.2 m®/kg, and the specific volume v2=0.8 m/kg in the P-v property diagram. a. The isothermal process from 1 to 2 state. b. The process from 2 to 3 state. c. The cyclic process of 1-2-3-1. d. Determine the work when the process from 1 to 2 state is the polytropic process (P = CV") with n=1.3. P.ka Kalev

Answer 1

As proceon 1 to 2 is isothermal so P. V = h. V 750 kPax 0.2m/= P₂ X 0.8 milkg px - 750 kPa -187-5kla a) Wsz - – Piv, ln V = - 750 X 0:2 klaxmi kg lng = - 150 x 10 11 dny J - – 2287.385 kJ (for 1kg) (for 11 kg) 6) W 273 = - P(V, V) -- 187.5 (0.2 - 0.8) kla xm x 11 kg - 61237.5 kJ + w twin - - 2287.385+ 1237.5 to 242 371 70 el 142 [isochonic) -- 1049.885 kJ - 1871.47 kJ (d) Weltrein = P₂V _P, V _ [123.70% 0 8 – 750 x 0.2] 11 1.301 nal [ bv. = P, vd s le P. C. 750 (02) - 123 Aokla)