function [etha, etha_pm]=przegrzew(P0, Ppm, Pk)
%%Entalpie
%P0 = 180;
%Ppm = 40;
%Pk = 0.05;
i0 = XSteam('h_pT',P0, 530);
s0 = XSteam('s_pT', P0, 530);
ipm1 = XSteam('h_ps', Ppm, s0);
ipm2 = XSteam('h_pT', Ppm, 530);
spm = XSteam('s_pT', Ppm, 530);
ik = XSteam('h_ps', Pk, spm);
iz = XSteam('hL_p', Pk);
%%Sprawność (układ z międzystopniowym przegrzewem pary)
etha_pm = ((i0-ipm1)+(ipm2-ik))/((i0-iz)+(ipm2-ipm1));
%%Sprawność (układ bez przegrzewu)
etha = (i0-ik)/(i0-iz);
%%Wykresy i-s dla różnych ciśnień
for s=1:10
i01(s) = XSteam('h_ps', P0, s);
ipm(s) = XSteam('h_ps', Ppm, s);
ik1(s) = XSteam('h_ps', Pk, s);
end
s=1:10;
figure
plot(s,i01,s,ipm,s,ik1);
grid on
ylim ([0 4000]);
xlim ([1 8]);
legend ('18 MPa', '4 MPa', '5 kPa');
xlabel('Entropia');
ylabel('Entalpia');
hold on
plot(s0, i0, 'b*');
sx=[s0 s0 spm spm];
ix=[i0 ipm1 ipm2 ik];
text(s0, i0, num2str(i0, '%4.1f'));
text(s0, ipm1, num2str(ipm1, '%4.1f'));
text(spm, ipm2, num2str(ipm2, '%4.1f'));
text(spm, ik, num2str(ik, '%4.1f'));
plot(sx, ix, '-r*', 'LineWidth',2);
hold off
end