Question

Investigate the feasibility of the process described below, based on the I. and II. Law of thermodynamics! In a "black box (see figure) air of 0.5 kg/s flows continuously at a temperature of 10°C and a pressure of 100 kPa. In the box, "something happens to the air and then leaves it through two openings. The state of the air leaving the first opening is 110C, 100 kPa and the mass flow is 0.05 kg / s. The pressure of the air leaving the other opening is 100 kPa. There is no interaction between the "box" and its surroundings. The isobaric specific heat of air is 1004 J/(kg-K), constant value. Determine the temperature of the air, leaving the second opening (marked by 3). 1 "black box" 2 3

Answer 1

Given m=0.5kg/s Ti=10°C= 283X. P,=100kPa. P2 = 100kPa. T2 -110°C = 3831, m2=0.05 0.059's P3= 100kPa. (p = 1004Jully Blaulibon 2 3

Solution By 1st low of Thermodynamics d (u+PE+k.b) = 0 + W + Emin at (hint P.E;n+RE.;o)-Em out (hout +Plut +Ktout Assumption:- Osteady state Condition (e) d (u+P"€72.6)=0 It ② P.E & Kinetic energy are neglected 3. There is no work done & heat Transfer idzo, wzo. ut. Eńhin-Emhout=o. Emihin= sinhout m. ho- mahatma ha By Ind & Conserwation energy Also mais conservation mi= matina 0.5=0.05+m3 n3=0.45 kg 13 0.5xſdoq x 283–8:05X1004x383) 46-45*1064X13) 141.5= 19.157 0.4572 sed 13=27):881-101190 Grove dotated scuton, please update If doubt please comment