1. The document describes a gas turbine cycle with intercooling between compression stages, regeneration of exhaust heat, and reheating between expansion stages. 2. Key parameters of the cycle include air entering the compressor at 290K and 100kPa and being compressed to 0.41MPa then cooled to 286K before further compression to 0.75MPa. 3. The turbine exhausts at 0.1MPa after expanding down to 0.41MPa at 1350K and being reheated to 1350K before further expansion. 4. The overall thermal efficiency of the cycle is calculated to be 54.3% based on the given parameters.

1. ĐẠI HỌC QUỐC GIA TP. HỒ CHÍ MINH
TRƯỜNG ĐẠI HỌC BÁCH KHOA
KHOA KỸ THUẬT GIAO THÔNG
-----    -----
BK
TP.HCM
BÀI TẬP VỀ NHÀ
Môn học: Động cơ & bộ dẫn tiến (213716)
Chương 3: Gas power cycles
Nhóm: 01
Danh sách thành viên:
Nguyễn Thị Anh Thy 1710325
Trần Hải Đăng 1710068
Học kỳ: HK202
Giảng viên: TS. Trần Tiến Anh
Ngày nộp: 24/03/2021

2. Nhóm: 01
BÀI LÀM
Problem 3.6 A gas turbine installation has intercooling, regeneration and reheating
with air entering compressor at 100 kPa, 290 K and compressed to 0.41 MPa.
Subsequently it is cooled until temperature drops to 13oC in intercooler and finally
compressed to 0.75 MPa. Regenerator effectiveness is 0.70 and turbine inlet
temperature (TIT) is 1350 K and expands to 0.41 MPa where it is reheated up to
1350 K. The exhaust pressure is 0.1 MPa. Determine overall efficiency considering
expansion and compression processes to be of isentropic type. Take air as working
fluid throughout. [54.3%]
Solution:
Summary from given information:
1 1
2
3 3
4
6 6
7
8 8
9
290 , 100 0.1
0.41
13 286 , 0.41
0.75
1350 , 0.75
0.41
1350 , 0.41
0.1
o
T K P kPa MPa
P MPa
T C K P MPa
P MPa
T K P MPa
P MPa
T K P MPa
P MPa
     
 
    
 
   
 
   
 
As shown below, a regenerative gas turbine with reheating during expansion and
intercooling when compression is considered. This combination increases net work
output and thermal efficiency significantly.
Figure 1. Thermodynamic representation of gas turbine cycle with regeneration,
reheat and intercooling.

3. Nhóm: 01
Figure 2. Schematic for gas turbine cycle with regeneration, reheat and intercooling.
C1: Low pressure compressor stage
C2: High pressure compressor stage
CC: Combustion chamber
RCC: Reheat combustion chamber
T1: High pressure turbine stage
T2: Low pressure turbine stage
G: Generator
For process 1-2 3-4 6-7 8-9 which are of isentropic type, we have following equation:
1 1 1.4 1
1.4
2 2 2
2 1
1 1 1
1 1 1.4 1
1.4
4 4 4
4 3
3 3 3
1 1
7 7 7
7 6
6 6 6
0.41
* 290* 434 ( )
0.1
0.75
* 286* 340 ( )
0.41
0.41
* 1350*
0
T P P
T T K
T P P
T P P
T T K
T P P
T P P
T T
T P P
 
 
 
 
 
 
  
  
 
     
     
     
 
   
     
     
     
 
   
   
   
   
   
1.4 1
1.4
1 1 1.4 1
1.4
9 9 9
9 8
8 8 8
1136 ( )
.75
0.1
* 1350* 902 ( )
0.41
K
T P P
T T K
T P P
 
 

  
 
 
 
 
     
     
     
 
   
Regenerator effectiveness:
5 4
5 9 4 4
9 4
0.7 *( ) 0.7*(902 340) 340 733( )
regen regen
T T
T T T T K
T T
 

          


4. Nhóm: 01
Based upon air standard cycle considerations thermodynamic analysis gives the net work output
from cycle and heat added:
Net work output:
               
6 7 8 9 4 3 2 1 6 7 8 9 4 3 2 1
* *
net P
W m h h h h h h h h m C T T T T T T T T
               
   
   
Heat added:
   
6 5 8 7 6 5 8 7
( ) ( ) * * ( ) ( )
add P
Q m h h h h m C T T T T
       
Therefore, Cycle thermal efficiency:
       
       
6 7 8 9 4 3 2 1
6 5 8 7
( ) ( )
1350 1136 1350 902 340 286 434 290
55.8%
(1350 733) (1350 1136)
cycle
T T T T T T T T
Net work
Heat added T T T T

      

 
   
      
 
  