In an ideal Brayton cycle, air is compressed from 100 kPa and 25°C to 800 kPa, and then heated to 1200°C before entering the turbine. Under cold air standard conditions, the air temperature at the turbine exit is
A)540°C
B)184°C
C)150°C
D)813°C
E)825°C

Question

Quizplus · Accepted Answer

Solved by EES Software. Solutions can be verified by copying-and-pasting the following lines on a blank EES screen. 
P1=100 "kPa"
P2=800 "kPa"
T1=25+273 "K"
T3=1200+273 "K"
rp=P2/P1
k=1.4
T4=T3*(1/rp)^((k-1)/k)-273
 
"Some Wrong Solutions with Common Mistakes:"
W1_T4 = T3/rp "Using wrong relation"
W2_T4 = (T3-273)/rp "Using wrong relation"
W3_T4 = T4+273 "Using K instead of C"
W4_T4 = T1+800-273 "Disregarding temp rise during compression"

In an Ideal Brayton Cycle, Air Is Compressed from 100