Thermal Efficiency Problem

Q. The is and temp of air are 1 bar and Expansion 300 K. compression find ratio Thermal is 7.5. efficiency, If the temp , mom of pr, air max after temp computersion and mean is 550 K. pressure. given: P1=1 bar = T,=300K and 14 is Re = 7.5 Tn= 550K. A Putty The v Pill in I Thermal efficiency :- / 1-1 F Notto= 1- so (R))- 102.) Noth 55% 2 man. pressure P3 Process 4-1 P3VS P3 - hey r ) P4 wh pite, - V, T1 Pay TH P3 = 24 P4 vs = (vi) 24 Py P.T. 4 TI (7.5) Pro 11 550 300 P3- (16.79xp4) Pr 1.83 ba P3 = 1.83x16.79 Ps 30.725 bay

3) man. Temperature: FI (Re) +-1 (9.5) Ty T3 = 550 (7.599 T3= 1231.36K 4 Qr= = 1x0.718v(550-300) Qr = 179.5 kj/kg T2 = (17 r-1 (R.) TI Qs. - 1x0.718 (1231.36-671.65) T, = (7.5) 4 4 X 300 Qs= 401.86 KJ/kg T2 = 671.65K 5 W.D = Q5-Q = 222.36 1- (59) P,V,= MRTI 24= 1x287xx00 - 0.861 m3/leg 1x105 Rc= 24 V2 , U2 = 0.861 = 10.1148 7/kg 7.5 Pm= ( 401-86-179.5) (0.861-0.114f) Pm= 2.97 bar Q. An engine 20 un Bove and 30 (ID stroke works on otto cycle. The clearance volume is 1600 cm The initial pr and Temp are 1 Bav and 60c. If the man pv is limited to 24 Bar. find the following: a The Air standard Efficiency of the cycle. b The Mean Effective Pr. Given, D- 20 un , L= 30 cm To find Notto." Ne = 1600 mm Pn= ? P,= 1 Bar T1 = 60°C = 333K

solution: V3 = T D'LL 4 - I x (20)'x30 - 9424.7705 4 Vs+v, - 9424.+1600 Ve 1600 Re=6.59 Thamal Efficiency - 1- I (Re) 5-1 = 53.79% (6.59) mean Effective pressure, 5-1 Pm= (---) x (Re)-1 Re-1 x pressure Ratio 0 - 01x1 X= P3 - 24 = = B 1.14.91 ar X= 1.609 32.1.A) P2 > (#/ VI visit up. deposit P2 = -P, that P,= = 14.91 ba Pm= 1x105x 6.89 (1.61-1) ( (6.59) (1.4-1) 6.89 = 2.078105 Pm= 2.07x10 Pm. 2.07 bar