Rankine Cycle Simulator
Aim-Create a Rankine Cycle Simulator using OCTAVE/MATLAB.
OBJECTIVE-
Create a Rankine Cycle Simulator using OCTAVE/MATLAB.
calculate the state points of the Rankine Cycle (any type of your choice) based on user inputs.
plot the corresponding T-s and h-s plots for the given set of inputs.
LIBRARY USED-
The link for the standard Xsteam library to get the steam table data for water is given below. It must be used to calculate the points in between the state variables.
Click here to download the Xsteam Library.
Provided Inputs-
Turbine Inlet temperature = 400° C
Turbine Inlet Pressure = 30 bars
Turbine Outlet Pressure = 0.05 bars = Condenser Inlet Pressure
THEORY-
Process 1-2: Reversible adiabatic expansion in the turbine.
Process 2-3: Constant-pressure transfer of heat in the condenser.
Process 3-4: Reversible adiabatic pumping process in the feed pump.
Process 4-1: Constant-pressure transfer of heat in the boiler.
STEPS & ALGORITHM EXPLANATION-
Taking all inputs arguments.
Calculation of Cp value at P1 & P2 for saturated liquid & vapour
Calculation of Saturation Temperature at P1 & P2
Calculation of saturation properties at state 1, 2, 3 and 4
Calculation of Process properties at state 1, 2, 3, and 4
Calculation & Plotting saturation Liquid and Vapour lines.
Plotting T-s Plot
Plotting h-s Plot
Calculation of Work done, heat, SSC, and efficiency
Main Code-
file name- Rankin_cycle.m
clear all
close all
clc
% Print discription of all process
P1 = input('Pressure at the Turbine Inlet (in bar): ');
T1 = input('Temperature at the Turbine inlet (in Degree celsius): ');
P2 = input('Pressure at the Condenser (in bar): ');
fprintf('RESULTn');
% Calculation of Cp value at P1 & P2 for saturated liquid & vapour
CP1_L=XSteam('CpL_p',P1);
CP1_V=XSteam('CpV_p',P1);
CP2_L=XSteam('CpL_p',P2);
CP2_V=XSteam('CpV_p',P2);
Tsat_P1=XSteam('Tsat_p',P1);
Tsat_P2=XSteam('Tsat_p',P2);
% Calculation of saturation properties at state 1
Hg_1=XSteam('hV_p',P1);
Sg_1=XSteam('sV_p',P1);
% Calculation of saturation properties at state 2
Hg_2=XSteam('hV_p',P2);
Sg_2=XSteam('sV_p',P2);
% Calculation of saturation properties at state 3
Hf_3=XSteam('hL_p',P2);
Sf_3=XSteam('sL_p',P2);
% Calculation of saturation properties at state 4
Hf_4=XSteam('hL_p',P1);
Sf_4=XSteam('sL_p',P1);
% Calculation of Process properties at state 1
fprintf('At State point 1n');
fprintf('P1 is :%f Barn',P1);
fprintf('T1 is :%f degCn',T1);
H1=XSteam('h_pT',P1,T1);
fprintf('H1 is :%f kJ/kgn',H1);
S1=XSteam('s_pT',P1,T1);
fprintf('S1 is :%f kJ/kgnn',S1);
% Calculation of Process properties at state 2
fprintf('At state point 2n');
fprintf('P2 is : %f Barn', P2);
S2 = S1;
fprintf('S2 is : %f kJ/kgKn', S2);
%Calculating value of X
if(S2<=Sg_2)
X2 = (S2 - Sf_3) / (Sg_2-Sf_3); % Dryness Fraction at state point 2
else
X2=1;
end
fprintf('X2 is :%f n', X2);
%calculating value of T2
if(X2<1)
T2=Tsat_P2;
else
%S2=Sg_2+CP2_V*(log(T2/Tsat_P2))
T2=(Tsat_P2+273.15)*exp((S2-Sg_2)/CP2_V) ;
T2=T2-273.15;
end
fprintf('T2 is : %f degC n', T2)
if(X2<1)
H2 = Hf_3 + X2 * (Hf_3-Hg_2);
else
H2=XSteam('h_pT',P2,T2);
end
fprintf('H2 is : %f kJ/kgnn', H2)
% Calculation of Process properties at state 3
fprintf('At state point 3n')
P3 = P2;
fprintf('P3 is : %f Barn', P3)
V3 = XSteam('vL_p', P3);
T3 = Tsat_P2; % No subcooling assumed
fprintf('T3 is : %f degCn', T3)
H3 =Hf_3;
fprintf('H3 is : %f kJ/kgn', H3)
S3 =Sf_3;
fprintf('S3 is : %f kJ/kgKnn', S3)
% Calculation of Process properties at state 4
fprintf('At state point 4n')
P4 = P1;
fprintf('P4 is : %f Barn', P4)
S4 = S3;
fprintf('S4 is : %f kJ/kgKn', S4)
Wp = V3 * (P4 - P3) * 100;
H4 = Wp + H3;
fprintf('H4 is : %f kJ/kgn', H4)
T4= (Tsat_P1+273.15)/(exp((Sf_4-S4)/CP1_L));
T4=T4-273.15;
fprintf('T4 is : %f Deg celsius nn', T4)
% Calculation & plotting saturation Liquid and Vapour lines
temp = linspace(1, T1, 1000);
for i = 1 : length(temp)
H_L(i) = XSteam('hL_T', temp(i));
H_V(i) = XSteam('hV_T', temp(i));
S_L(i) = XSteam('sL_T', temp(i));
S_V(i) = XSteam('sV_T', temp(i));
end
% Plotting T-s Plot
figure(1)
hold on
plot([S1 S2], [T1 T2], 'r', 'linewidth', 2)
text(S1,T1,' 1')
text(S2,T2,' 2')
plot([S2 Sg_2], [T2 Tsat_P2], 'r', 'linewidth', 2)
text(Sg_2,Tsat_P2,' 2s')
plot([Sg_2 S3], [Tsat_P2 T3], 'r', 'linewidth', 2)
text(S3,T3,' 3')
plot([S3 S4], [T3 T4], 'r', 'linewidth', 2)
text(S4,T4,' 4')
plot([S4 Sf_4], [T4 Tsat_P1], 'r', 'linewidth', 2)
text(Sf_4,Tsat_P1,' 4s')
plot([Sf_4 Sg_1], [Tsat_P1 Tsat_P1], 'r', 'linewidth', 2)
text(Sg_1,Tsat_P1,' 1s')
plot([Sg_1 S1], [Tsat_P1 T1], 'r', 'linewidth', 2)
plot(S_L, temp, 'b', 'linestyle','--','linewidth', 1)
plot(S_V, temp, 'b', 'linestyle','--','linewidth', 1)
title('T-S Diagram of Ideal Rankine Cycle')
ylabel('Temprature (degC)')
xlabel('Specific Entropy (kJ/kgK)')
% Plotting H-S Plot
figure(2)
hold on
plot([S1 S2], [H1 H2], 'r', 'linewidth', 2)
text(S1,H1,' 1')
text(S2,H2,' 2')
plot([S2 Sg_2], [H2 Hg_2], 'r', 'linewidth', 2)
text(Sg_2,Hg_2,' 2s')
plot([Sg_2 S3], [Hg_2 H3], 'r', 'linewidth', 2)
text(S3,H3,' 3')
plot([S3 S4], [H3 H4], 'r', 'linewidth', 2)
text(S4,H4,' 4')
plot([S4 Sf_4], [H4 Hf_4], 'r', 'linewidth', 2)
text(Sf_4,Hf_4,' 4s')
plot([Sf_4 Sg_1], [Hf_4 Hg_1], 'r', 'linewidth', 2)
text(Sg_1,Hg_1,' 1s')
plot([Sg_1 S1], [Hg_1 H1], 'r', 'linewidth', 2)
plot(S_L, H_L, 'b','linestyle','--', 'linewidth', 1.5)
plot(S_V, H_V, 'b','linestyle','--', 'linewidth', 1.5)
title('H-S Diagram of Ideal Rankine Cycle')
ylabel('Specific Enthalpy (kJ/kg)')
xlabel('Specific Entropy (kJ/kgK)')
mkdir('C:UsersASUSDesktopmatlabrankIne cYcle');
cd('C:UsersASUSDesktopmatlabrankIne cYcle')
saveas(1,'1');
saveas(2,'2');
% Calculation of Work done, heat, SSC and efficiency
Wt = H1 - H2;
fprintf('Work by turbine is : %f kJ/kgn', Wt)
fprintf('Work by compressor is : %f kJ/kgn', Wp)
Wnet = Wt - Wp;
fprintf('Net Wok done is : %f kJ/kgn', Wnet)
Qin = H1 - H4;
eff_thermal = Wnet*100 / Qin ; % Effieciency
fprintf('Thermal efficiency is : %f', eff_thermal); disp('%')
SSC = 3600 / Wt; % Specific steam consuption
fprintf('S.S.C is : %f kg/kWh ', SSC)Output-
Command window Result-