FINAL INDEPENDENT PROJECT

Here in this project i have chosen the topic about the brayton cycle -

Let's have a look into the basics of this cycle how it works

Gas turbines are also Brayton engines, with three components: a gas compressor, a burner (or combustion chamber), and an expansion tube.

Brayton Cycle- It is the ideal cycle for gas turbine engines in which the working fluid undergoes through a closed loop.

Working Principle-

• Fresh air enters the compressor at ambient temperature where its pressure and temperature are incresed.
• The high pressure air enters the combustion chamber where the fluel is burned at constant pressure.
• The High Temperature (and Pressure) gas enters the turbine where it expands to ambient Pressure and produces Work

Task- A gas turbine based on Brayton Cycle has a net power capacity of 2MW. Air enters the compressor at 2.78 Mpa, 26deg C. the pressure ratio in the cycle is 2.41. the gas enters the turbine at the pressure of .7 Mpa, 917 deg C. where it is exhaust at the pressure of 2.78 Mpa.

1. Find all enthalpy at all staes
2. compressor outlet T2
3. Heat addition by Combustion Chamber
4. Workdone by compressor and Turbine
5. Thermal Eff

MATLAB Code- i have started with basic commands like close all, clear all, clc.. in mentioned comments explain all 4 cycles calculated enthalpy and entropy using xsteam function.

make sure Xsteam function should be in the working directory to avoid errors.

clear all
close all
clc

disp('   Brayton Cycle Numerical Example  ');
disp('1-2 is isentropic Compression in the Compressor');
disp('2-3 is Constant Pressure heat-addition in the Cumbustion Chamber');
disp('3-4 is isentropic Expansion in the Turbine');
disp('4-1 is Constant Pressure heat Rejection by the Exhaust');
fprintf('n')

% Taking Inputs 
P1= 27.8;% Pressure in Bar
T1= 26; % Temp in Deg Celcius
P4= P1;
P3= 67;
T3= 917;
P2= P3;

PrRatio= P2/P1
h1= XSteam('h_pT',P1,T1)
S1= XSteam('s_pT',P1,T1);
S2=S1;
T2=XSteam('T_ps',P2,S2);
h2=XSteam('h_pT',P2,T2);
h3=XSteam('h_pT',P3,T3);
S3=XSteam('s_pt',P3,T3);
S4=S3;
T4=XSteam('T_ps',P4,S4);
h4=XSteam('h_pt',P4,S4);
Qin= h3-h2;   
Wt=h3-h4
Wc=h2-h1
Qout= h4-h1
Eff= abs(1-Qout/Qin)*100

Output Values-