%%%%%%%%%%%%    Renewable Energy  %%%%%%%%%%%
%%%%%%%%%%%%%    Solution 6 ex 6   %%%%%%%%%%%%
close all;
clear all;
clc;

% Rankine cycle
K=273.15; % K to °C
Atm=1.01325; % Atm to bar

%%%%%%%%%%%%%%%%%%%  ex.6 i) %%%%%%%%%%%%%%%%%%%%% 

% Point 1
T11=320; % unit in °C
T1=T11-K;
N=length(T1);
P1=XSteam('Psat_T',T1); % unit in bar
H1=XSteam('hL_T',T1); % unit in KJ/kg
v1=XSteam('vL_T',T1); % unit in m3/kg


% Point 2
T2=325-K;
P2=70:10:250;
N=length(P2);
H2=zeros(1,N);
for i=1:N
H2(i)=H1+v1.*(P2(i)-P1).*100; % unit kJ/kg
end

% Point 3
T3=542;
P3=P2;
H3=zeros(1,N);
S3=zeros(1,N);

for i=1:N
H3(i)=XSteam('h_pT',P3(i),T3); % unit kJ/kg
S3(i)=XSteam('s_pT',P3(i),T3); % unit kJ/kg
end
H3_2=H3-H2;

% Point 4
T4=T1;
P4=P1;
%w4=0.85:0.01:0.95;
w4=0.925; %Steam quality
%hL4=zeros(1,N);
%hV4=zeros(1,N);
%for i=1:N
hL4=XSteam('hL_T',T4);
hV4=XSteam('hV_T',T4);
sL4=XSteam('sL_T',T4);
sV4=XSteam('sV_T',T4);
%end
H4=hL4+w4.*(hV4-hL4);
S4=sL4+w4.*(sV4-sL4);
H4_3=H3-H4;
dS=S4-S3;


% Mass flow rate
W_turbine=19.9*1000; % kW need for 25'000 households
m_water=W_turbine./H4_3;

% Thermal heat power
Q=H3_2.*m_water./0.8; % in kW

% Mass flow of molten salt
cp=1.55; % heat capacity of molten salt kJ/kg/K
T_hot=T3+23; % temperature of hot tank in °C
T_cold=290; % temperature of cold tank in °C
m_salt=Q./(cp.*(T_hot-T_cold)); % kg/s

% Storage capacity of molten salt
rho=1750; % density of molten salt kg/m3
D=23; % diameter of tanks
H=14; % height of tanks
V=(D/2)^2*pi()*H; % volume of tank in m3
t=V.*rho./m_salt./3600; % storage in hours

%  Plot

figure(1); 
plot(P3,t,'color','k','LineWidth',2,'MarkerSize',12);hold on;
set(gca,'Fontsize',12);
xlabel('Turbine inlet pressure (bar)','Fontsize',14);
ylabel('Storage capacity time (h)','Fontsize',14);

fig1=figure(1);
print(fig1,'Storage_i','-dpng');
% figure(2); 
% plot(T3,m_salt,'color','k','LineWidth',2,'MarkerSize',12);hold on;
% set(gca,'Fontsize',12);
% xlabel('Condenser outlet temperature (°C)','Fontsize',14);
% ylabel('Molten salt mass flow (kg/s)','Fontsize',14);

% fig2=figure(2);
% print(fig2,'Salt_T3','-dpng');

%%%%%%%%%%%%%%%%%%%  ex.6 ii) %%%%%%%%%%%%%%%%%%%%% 

% Point 1
T11=320; % unit in °C
T1=T11-K;
N=length(T1);

P1=XSteam('Psat_T',T1); % unit in bar
H1=XSteam('hL_T',T1); % unit in KJ/kg
v1=XSteam('vL_T',T1); % unit in m3/kg

% Point 2
T2=325-K;
P2=100;
H2=H1+v1.*(P2-P1).*100; % unit kJ/kg

% Point 3
T3=400:10:750;
N=length(T3);
P3=P2;
H3=zeros(1,N);
S3=zeros(1,N);
for i=1:N
H3(i)=XSteam('h_pT',P3,T3(i)); % unit kJ/kg
S3(i)=XSteam('s_pT',P3,T3(i)); % unit kJ/kg
end
H3_2=H3-H2;

% Point 4
T4=T1;
P4=P1;
w4=0.925; %Steam quality
hL4=XSteam('hL_T',T4);
hV4=XSteam('hV_T',T4);
sL4=XSteam('sL_T',T4);
sV4=XSteam('sV_T',T4);
H4=hL4+w4.*(hV4-hL4);
S4=sL4+w4.*(sV4-sL4);
H4_3=H3-H4;
dS=S4-S3;

% Mass flow rate
W_turbine=19.9*1000; % kW need for 25'000 households
m_water=W_turbine./H4_3;

% Thermal heat power
Q=H3_2.*m_water./0.8; % in kW

% Mass flow of molten salt
cp=1.55; % heat capacity of molten salt kJ/kg/K
T_hot=T3+23; % temperature of hot tank in °C
T_cold=290; % temperature of cold tank in °C
m_salt=Q./(cp.*(T_hot-T_cold)); % kg/s

% Storage capacity of molten salt
rho=1750; % density of molten salt kg/m3
D=23; % diameter of tanks
H=14; % height of tanks
V=(D/2)^2*pi()*H; % volume of tank in m3
t=V.*rho./m_salt./3600; % storage in hours

%  Plot

figure(2); 
plot(T3,t,'color','k','LineWidth',2,'MarkerSize',12);hold on;
set(gca,'Fontsize',12);
xlabel('Turbine inlet temperature (°C)','Fontsize',14);
ylabel('Storage capacity time (h)','Fontsize',14);

fig2=figure(2);
print(fig2,'Storage_ii','-dpng');

%%%%%%%%%%%%%%%%%%%  ex.6 iii) %%%%%%%%%%%%%%%%%%%%% 

% Point 1
T11=320; % unit in °C
T1=T11-K;
N=length(T1);
P1=XSteam('Psat_T',T1); % unit in bar
H1=XSteam('hL_T',T1); % unit in KJ/kg
v1=XSteam('vL_T',T1); % unit in m3/kg


% Point 2
T2=325-K;
P2=100;
H2=H1+v1.*(P2-P1).*100; % unit kJ/kg

% Point 3
T3=542;
P3=P2;
H3=XSteam('h_pT',P3,T3); % unit kJ/kg
S3=XSteam('s_pT',P3,T3); % unit kJ/kg
H3_2=H3-H2;

% Point 4
T4=T1;
P4=P1;
w4=0.85:0.01:0.95; %Steam quality
N=length(w4); 
hL4=zeros(1,N);
hV4=zeros(1,N);
for i=1:N
hL4=XSteam('hL_T',T4);
hV4=XSteam('hV_T',T4);
sL4=XSteam('sL_T',T4);
sV4=XSteam('sV_T',T4);
end
H4=hL4+w4.*(hV4-hL4);
S4=sL4+w4.*(sV4-sL4);
H4_3=H3-H4;
dS=S4-S3;

% Mass flow rate
W_turbine=19.9*1000; % kW need for 25'000 households
m_water=W_turbine./H4_3;

% Thermal heat power
Q=H3_2.*m_water./0.8; % in kW

% Mass flow of molten salt
cp=1.55; % heat capacity of molten salt kJ/kg/K
T_hot=T3+23; % temperature of hot tank in °C
T_cold=290; % temperature of cold tank in °C
m_salt=Q./(cp.*(T_hot-T_cold)); % kg/s

% Storage capacity of molten salt
rho=1750; % density of molten salt kg/m3
D=23; % diameter of tanks
H=14; % height of tanks
V=(D/2)^2*pi()*H; % volume of tank in m3
t=V.*rho./m_salt./3600; % storage in hours

%  Plot

figure(3); 
plot(w4,t,'color','k','LineWidth',2,'MarkerSize',12);hold on;
set(gca,'Fontsize',12);
xlabel('Turbine outlet steam quality (-)','Fontsize',14);
ylabel('Storage capacity time (h)','Fontsize',14);

fig3=figure(3);
print(fig3,'Storage_iii','-dpng');

%%%%%%%%%%%%%%%%%%%  ex.6 iv) %%%%%%%%%%%%%%%%%%%%% 

% Point 1
T11=290:1:320; % unit in °C
T1=T11-K;
N=length(T1);
P1=zeros(1,N);
H1=zeros(1,N);
v1=zeros(1,N);

for i=1:N
P1(i)=XSteam('Psat_T',T1(i)); % unit in bar
H1(i)=XSteam('hL_T',T1(i)); % unit in KJ/kg
v1(i)=XSteam('vL_T',T1(i)); % unit in m3/kg
end

% Point 2
T2=325-K;
P2=100;
H2=H1+v1.*(P2-P1).*100; % unit kJ/kg

% Point 3
T3=542;
P3=P2;
H3=XSteam('h_pT',P3,T3); % unit kJ/kg
S3=XSteam('s_pT',P3,T3); % unit kJ/kg
H3_2=H3-H2;

% Point 4
T4=T1;
P4=P1;
w4=0.925; %Steam quality
hL4=zeros(1,N);
hV4=zeros(1,N);
for i=1:N
hL4(i)=XSteam('hL_T',T4(i));
hV4(i)=XSteam('hV_T',T4(i));
sL4(i)=XSteam('sL_T',T4(i));
sV4(i)=XSteam('sV_T',T4(i));
end
H4=hL4+w4.*(hV4-hL4);
S4=sL4+w4.*(sV4-sL4);
H4_3=H3-H4;
dS=S4-S3;

% Mass flow rate
W_turbine=19.9*1000; % kW need for 25'000 households
m_water=W_turbine./H4_3;

% Thermal heat power
Q=H3_2.*m_water./0.8; % in kW

% Mass flow of molten salt
cp=1.55; % heat capacity of molten salt kJ/kg/K
T_hot=T3+23; % temperature of hot tank in °C
T_cold=290; % temperature of cold tank in °C
m_salt=Q./(cp.*(T_hot-T_cold)); % kg/s

% Storage capacity of molten salt
rho=1750; % density of molten salt kg/m3
D=23; % diameter of tanks
H=14; % height of tanks
V=(D/2)^2*pi()*H; % volume of tank in m3
t=V.*rho./m_salt./3600; % storage in hours

%  Plot

figure(4); 
plot(T1,t,'color','k','LineWidth',2,'MarkerSize',12);hold on;
set(gca,'Fontsize',12);
xlabel('Condenser outlet temperature (°C)','Fontsize',14);
ylabel('Storage capacity time (h)','Fontsize',14);

fig4=figure(4);
print(fig4,'Storage_iv','-dpng');