Project 2 - Rankine cycle Simulator

Aim: To create a Rankine Cycle Simulator using MATLAB using a set of inpute and to plot T-s and h-s plots for the given set of inputs.

Processes:

1-2 : Isentropic expansion in turbine.

2-3 : Constant pressure heat adddition in condenser.

3-4 : Isentropic compression by Pump.

4-1 : Constant pressure heat rejection in boiler.

Main code:

clear all 
close all
clc

%turbine property calculation
    turbine_temp_inlet = input('Input turbine inlet temperature in degreeC :');
    turbine_pr_inlet = input('Input turbine inlet Pressure in bar :');
    turbine_pr_outlet = input('Input turbine outlet Pressure in bar :');
    turbine_enthalpy_inlet = XSteam('h_pT',turbine_pr_inlet,turbine_temp_inlet);
    turbine_entropy_inlet = XSteam('s_ph',turbine_pr_inlet,turbine_enthalpy_inlet);
    turbine_entropy_outlet = turbine_entropy_inlet;
    turbine_enthalpy_outlet = XSteam('h_ps',turbine_pr_outlet,turbine_entropy_outlet);
    turbine_temp_outlet = XSteam('T_hs',turbine_enthalpy_outlet,turbine_entropy_outlet);
    turbine_dryness_outlet = XSteam('x_ph',turbine_pr_outlet,turbine_enthalpy_outlet);

%Condenser property calculation
    condenser_pr_inlet = turbine_pr_outlet;
if turbine_dryness_outlet<1
   condenser_temp_inlet = turbine_temp_outlet;
   condenser_entropy_inlet = turbine_entropy_outlet;
   condenser_enthalpy_inlet = turbine_enthalpy_outlet;
else
    condenser_temp_inlet = XSteam('Tsat_p',condenser_pr_inlet)
    condenser_entropy_inlet = XSteam('sV_p',condenser_pr_inlet)
    condenser_enthalpy_inlet = XSteam('hV_p',condenser_pr_inlet)
end
    

%Pump property calculation
    pump_pr_inlet = condenser_pr_inlet;
    pump_temp_inlet = XSteam('Tsat_p',pump_pr_inlet);
    pump_enthalpy_inlet = XSteam('hL_p',pump_pr_inlet);
    pump_entropy_inlet = XSteam('sL_p',pump_pr_inlet);

%Boiler property calculation
    boiler_entropy_inlet = pump_entropy_inlet;
    boiler_pressure_inlet = turbine_pr_inlet;
    boiler_enthalpy_inlet = XSteam('h_ps',boiler_pressure_inlet,boiler_entropy_inlet);
    boiler_temp_inlet = XSteam('T_hs',boiler_enthalpy_inlet,boiler_entropy_inlet);
    upper_sattemp = XSteam('Tsat_p',boiler_pressure_inlet);
    boiler_satenthalpy_inlet = XSteam('hL_T',upper_sattemp);
    boiler_satenthalpy_outlet = XSteam('sV_T',upper_sattemp);
    boiler_satentropy_inlet = XSteam('sL_T',upper_sattemp);
    boiler_satentropyvapour_inlet = XSteam('sV_T',upper_sattemp);



    temp = linspace(1,400,100);
for i = 1:length(temp)
    entropy_V(1,i) = XSteam('sV_T',temp(i));
    entropy_L(1,i) = XSteam('sL_T',temp(i));
    enthalpy_V(1,i) = XSteam('hV_T',temp(i));
    enthalpy_L(1,i) = XSteam('hL_T',temp(i));
end
    figure(1)
    hold on
%Plotting the curve 1 t-s curve
    plot([turbine_entropy_inlet turbine_entropy_outlet],[turbine_temp_inlet turbine_temp_outlet],'-','linewidth',1.2,'color','b')

    plot([turbine_entropy_outlet condenser_entropy_inlet],[turbine_temp_outlet condenser_temp_inlet],'-','linewidth',1.2,'color','c')

    plot([condenser_entropy_inlet pump_entropy_inlet],[condenser_temp_inlet pump_temp_inlet],'-','linewidth',1.2,'color','c')

    plot([pump_entropy_inlet boiler_entropy_inlet],[pump_temp_inlet boiler_temp_inlet],'-','linewidth',1.2,'color','g')

    plot([boiler_entropy_inlet boiler_satentropy_inlet],[boiler_temp_inlet upper_sattemp],'-','linewidth',1.2,'color','r')

    plot([boiler_satentropy_inlet boiler_satentropyvapour_inlet],[upper_sattemp upper_sattemp],'-','linewidth',1.2,'color','r')

    plot([boiler_satentropyvapour_inlet turbine_entropy_inlet],[upper_sattemp turbine_temp_inlet],'-','linewidth',1.2,'color','r')

    plot([entropy_L entropy_V],[temp temp],'linewidth',1.2,'color','k')

    legend('Turbine','Condenser','Pump','Boiler','location','northeast')
    ylabel('Temperature (^oC)')
    xlabel('Entropy (kJ/kgK)')
    axis([0 10 0 500])
    title('Temperature V/s Entropy')
    
%Plotting the curve 1 h-s curve
    figure(2)
    hold on

    plot([turbine_entropy_inlet turbine_entropy_outlet],[turbine_enthalpy_inlet turbine_enthalpy_outlet],'-','linewidth',1.2,'color','b')

    plot([turbine_entropy_outlet condenser_entropy_inlet],[turbine_enthalpy_outlet condenser_enthalpy_inlet],'-','linewidth',2,'color','c')

    plot([condenser_entropy_inlet pump_entropy_inlet],[condenser_enthalpy_inlet pump_enthalpy_inlet],'-','linewidth',2,'color','c')

    plot([pump_entropy_inlet boiler_entropy_inlet],[pump_enthalpy_inlet boiler_enthalpy_inlet],'-','linewidth',1.2,'color','g')

    plot([boiler_entropy_inlet turbine_entropy_inlet],[boiler_enthalpy_inlet turbine_enthalpy_inlet],'-','linewidth',1.2,'color','r')

    plot([entropy_L entropy_V],[enthalpy_L enthalpy_V],'linewidth',1.2,'color','k')

    ylabel('Enthalpy (kJ/kg)')
    xlabel('Entropy (kJ/kgK)')
    axis([0 10 0 4000])
    legend('Turbine','Condenser','Pump','Boiler','location','northeast')
    title('Enthalpy V/s Entropy')
%To print the values at each points
    fprintf('At state 1: \n P1 = %f \n T1 = %f \n H1 = %f \n S1 =%f\n\n',turbine_pr_inlet,turbine_temp_inlet,turbine_enthalpy_inlet,turbine_entropy_inlet)
    fprintf('At state 2: \n P2 = %f \n T2 = %f \n H2 = %f \n S2 =%f\n\n',condenser_pr_inlet,condenser_temp_inlet,condenser_enthalpy_inlet,condenser_entropy_inlet)
    fprintf('At state 3: \n P3 = %f \n T3 = %f \n H3 = %f \n S3 =%f\n\n',pump_pr_inlet,pump_temp_inlet,pump_enthalpy_inlet,pump_entropy_inlet)
    fprintf('At state 4: \n P4 = %f \n T4 = %f \n H4 = %f \n S4 =%\n\nf',boiler_pressure_inlet,boiler_temp_inlet,boiler_enthalpy_inlet,boiler_entropy_inlet)

Code explanation:

• Initiallly the code starts with the input of turbine inlet and outlet pressure and the inlet temperature
• The turbine inlet enthalpy is calculated by using inlet temperature and pressure.
• Subsequently the inlet entropy is calucalted by inputting the enthalpy found and pressure inputted.
• Being an isentropic process the outlet and inlet entropy of the turbine are same.
• Outlet enthalpy was found by using pressure outlet and entropy outlet.
• The outlet temperature was calculated by using outlet enthalpy and entropy.
• now the dryness of the outlet steam is calculated if the dryness is less than 1 then the inlet entropy, enthalpy and temperature of the condenser equals that of the property of turbine at outlet
• Else inlet entropy, enthalpy and temperature of the condenser will be sturated and the saturated vapour values of this is calculated with the help of turbine outlet pressure.
• The entropy, enthalpy and temperature at the boiler entropy is equal to the saturated liquid values at turbine outlet pressure.
• Now, the boiler entropy and pressure are same as that of the turbine.
• The temperature at inlet of boiler is computed from upper pressure limit and the entropy at inlet of the pump.
• The saturated liquid and vapour values are found at upper temperature limit.
• Each values are plotted.
• Also saturated liquid and vapour values of entropy and enthalpy was found for a set of temperature by using a for loop.

Results:

Screen shots of properties at each states:

Plot of Temperature v/s Entropy:

Plot of Enthalpy v/s Entropy: