Question

A heat engine operates between a source and a sink. The source temperatures vary from 300 to 1000°C. Heat is supplied to the heat engine at a steady rate of 1200 kJ/min. Using Matlab or Excel (or other) software, study the effects of the temperatures of the heat source and the heat sink on the maximum power produced and the cycle thermal efficiency. Plot the power produced and the cycle efficiency against the source temperature for sink temperatures of 0°C, 25°C, and 50°C, and discuss the results.

Answer 1

clc;clear all;close all;
%Source temperature
TH1=300:50:1000;%Source temperature is vary from 300 to 1000 with 5 increment.
TH=TH1+273;%To convert oC to Kelvine
%Sink temperature
TL1=[0 25 50];%in oC
TL=TL1+273;%in Kelvine
%Heat supplied
Qin=1200;
effi(1,:)=1-(TL(1)./TH);
effi(2,:)=1-(TL(2)./TH);
effi(3,:)=1-(TL(3)./TH);
figure
hold on
xlabel('Source Temperature in 0C (TH)')
ylabel('Efficiency')
title('Efficiency Vs TH with constant TL')
for i=1:3
plot(TH1,effi(i,:))
legendInfo{i} = ['TL = ' num2str(TL1(i))];   
end
legend(legendInfo)

%Maximum work
Wmax=effi*Qin;
figure
hold on
xlabel('Source Temperature in 0C(TH)')
ylabel('Maximum work in kJ/min')
title('Maximum Work Vs TH with constant TL')
for i=1:3
plot(TH1,Wmax(i,:))
legendInfo{i} = ['TL = ' num2str(TL1(i))];   
end
legend(legendInfo)