homework
This is a thermal-fluids system design homework about matlab. i have uploaded the instruction and one sample of that homework.
clear,clc; % clears variables and cleans screen%
% Rankine cycle inputs%
Pressure_turbine3 = ‘(3)What is the Pressure for the turbine inlet?(Bar)’;
P3 = (Pressure_turbine3);
%P3 = 125;% % [bar] pressure turbine 3 inlet
Temp_turbine3 = ‘(3)What is the Temperature for the turbine inlet?(C)’;
T3 = (Temp_turbine3);
%T3 = 500;% % [C] temperature turbine 3 inlet
Pressure_turbine5 = ‘(5)What is the Pressure for the turbine inlet?(Bar)’;
P5 = (Pressure_turbine5);
%P5 = 25;% % [bar] pressure turbine 4 inlet
Temp_turbine5 = ‘(5)What is the Temperature for the turbine inlet?(C)’;
T5 = (Temp_turbine5);
%T5 =500;% % [C] temperature turbine 4 inlet
Pressure_pump1 = ‘ (1) What is the pressure pump inlet? [bar] ‘;
P1 = (Pressure_pump1);
%P1 = 0.1;% % [bar] pressure pump inlet
Quality_pump1 = ‘ (1) What is the quality of the pump inlet?(Decimal form)’;
x1 = input (Quality_pump1);
%x1 = 0.00;% % [-] quality pump inlet
Temp_comp7 = ‘(7)What is the Temperature for the Compressor inlet?(C)’;
T7 = (Temp_comp7);
%T7=310;%
Temp_comb8 = ‘(8)What is the Temperature for the combustion chamber inlet?(C)’;
T8 = (Temp_comb8);
%T8=700;%
Temp_turbine9 = ‘(9)What is the Temperature for the turbine inlet?(C)’;
T9 = (Temp_turbine9);
%T9=1500;%
Temp_exch10 = ‘(10)What is the Temperature for the Heat exchanger inlet?(C)’;
T10 = (Temp_exch10);
%T10=850;%
Temp_exch11 = ‘(11)What is the Temperature for the Heat exchanger exit?(C)’;
T11 = (Temp_exch11);
%T11=520;%
Workgas = ‘What is the power generated by the top cycle?(MW)’;
W_gas = (Workgas);
%Wgas = 800000; % [kw]%
effeciency_turbine = ‘What is the effiecency of the turbine?’;
eff_turbine = (effeciency_turbine);
%eff_turbine = 0.88;% % [-] turbine efficiency
effeciency_pump = ‘What is the effiecency of the pump?’;
eff_pump = (effeciency_pump);
%eff_pump% = 0.8; % [-] pump efficiency
% Processing: Determine states
% state 3: boiler 3 output / turbine 3 input
s3 = XSteam( ‘s_pT’, P3, T3 );
h3 = XSteam( ‘h_ps’, P3, s3 );
% state 4: turbine 1 output / boiler 2 input
% – recall isentropic efficiency: eta_turbine = ( h3 – h4 ) / ( h3 – h4s )
P4 = P5;
s4s = s3;
h4s = XSteam( ‘h_ps’, P4, s4s ); % isentropic enthalpy
h4 = h3 – eff_turbine * ( h3 – h4s );% real enthalpy
s4 = XSteam( ‘s_ph’, P4, h4 );
T4 = XSteam( ‘T_ps’, P4, s4 );
% state 5: boiler 2 output / turbine 2 input
s5 = XSteam( ‘s_pT’, P5, T5 );
h5 = XSteam( ‘h_ps’, P5, s5 );
% state 6: turbine 2 output / condenser input
s6s = s5;
P6 = P1;
h6s = XSteam( ‘h_ps’, P6, s6s );
h6 = h5 – eff_turbine * ( h5 – h6s ); % real enthalpy
s6 = XSteam( ‘s_ph’, P6, h6 );
T6 = XSteam( ‘T_ps’, P6, s6 );
% additional / optional:
s6V = XSteam( ‘sV_p’ , P6 );
s6L = XSteam( ‘sL_p’ , P6 );
x6 = ( s6 – s6L ) / ( s6V – s6L );
% state 1: condenser output / pump input
T1 = XSteam( ‘Tsat_p’, P1 );
h1 = XSteam( ‘hL_p’ , P1 );
s1 = XSteam( ‘sL_p’ , P1 );
% state 2: pumpt output / boiler 3 input
P2 = P3;
s2s = s1;
h2s = XSteam( ‘h_ps’, P2, s2s );
h2 = h1 + (( h2s – h1)/ eff_pump);
s2 = XSteam( ‘s_ph’, P2, h2 );
T2 = XSteam( ‘T_ps’, P2, s2 );
% Post-Processing: Power / Heat – Produced / Consumed
% determine power, heat rates:
h7=h_air(T7);
h8=h_air(T8);
h9=h_air(T9);
h10=h_air(T10);
h11=h_air(T11);
w_turb = (h9 -h10);
w_comp = (h7- h8);
M_dot_gas= W_gas/(w_turb+w_comp);
w_turbine1 = ( h3 – h4 );
q_boiler2 = ( h5 – h4 );
w_turbine2 = ( h5 – h6 );
q_condenser = ( h1 – h6 );
w_pump = ( h2 – h1 );
q_boiler1 = ( h3 – h2 );
m_dot= ((h10-h11)*M_dot_gas)/(q_boiler2+q_boiler1);
W_dot_turbine1 = m_dot * ( h3 – h4 );
Q_dot_boiler2 = m_dot * ( h5 – h4 );
W_dot_turbine2 = m_dot * ( h5 – h6 );
Q_dot_condenser = m_dot * ( h1 – h6 );
W_dot_pump = m_dot * ( h2 – h1 );
Q_dot_boiler1 = m_dot * ( h3 – h2 );
W_steam=W_dot_turbine1+W_dot_turbine2-W_dot_pump;
W_steam=W_steam/1000;
Q_dot_in = Q_dot_boiler1 + Q_dot_boiler2;
W_gas=W_gas/1000;
Q_gas= (h9-h8)*M_dot_gas;
Q_gas=Q_gas/1000;
efficiency = ((W_gas+W_steam)/ (Q_gas))*100;
HeatRate=3412/(efficiency/100);
clc;
X = sprintf(‘The mass flow rate of air into the gas-turbine cycle is: n %dkg/s n’,round(M_dot_gas));
Y = sprintf(‘The rate of total heat input into the combustion chamber is: n %dMw n’,round(Q_gas));
Z = sprintf(‘The thermal efficiency of the combined cycle is: n %0.3f%% n’,efficiency);
disp(X);
disp(Y);
disp(Z); Homework 1
Thermo-Fluid Systems Design (MECH.4420)
Write a MATLAB program to analyze the combined gassteam power plant
shown below. The top cycle generates 800 MW of power.
Air enters the compressor at 310 K, the combustion chamber at 700 K and
the turbine at 1500 K. The combustion gases enter the heat exchanger at 850
K and exit at 520 K. The combustion gases exiting the gas turbine are used
to heat the steam (State 3) to 12.5 MPa to 500o C in a heat exchanger. Steam
expands in a high-pressure turbine to a pressure of 2.5 MPa and is reheated
in the heat exchanger to 500o C before it expands in a low-pressure turbine
to 10 kPa. Assume all heat exchangers operate at constant pressure and
isentropic efficiencies of 80.0 % for the pump, and 88 %for steam turbines.
Upload a .m file modeling this cycle. It should write to the screen ONLY the
following values. (a) the mass flow rate of air in the gas-turbine cycle, [kg/s]
(b) the rate of total heat input into the combustion chamber [MW], and (c)
the thermal efficiency of the combined cycle [%].
