Temperature profile must increase expoenetial but mine is decreasing,dy(15) is temperature profile diff equation.If ra or rp in code gets changed it changes because rest is constant

An adiabtic bathc reactor model is getting developed the function is given here,I have to get an exponential increase when plotting time vs temperature dy(15),but i am getting exponential decrease.Please help me with that

  function dy=adiabatic_batch(t,y)
    
    k=deadkineticestimation(y(15));
    
    dy=zeros(17,1);
    
    if(y(6)==0.0 || y(7)==0.0 || y(9)==0.0 || y(10)==0.0 || y(12)==0.0 || y(13)==0.0)
        lam3=0.0;
        mu3=0.0;
        gam3=0.0;
    else    
     lam3=(y(8)*((2*y(8)*y(6))-(y(7)*y(7))))./(y(7)*y(6));
     mu3=(y(11)*((2*y(11)*y(9))-(y(10)*y(10))))./(y(10)*y(9));
     gam3=(y(14)*((2*y(14)*y(12))-(y(13)*y(13))))./(y(13)*y(12));
    end
    
    Hra=50.100;%%kj/mol
    Hrp=-23.300;
    
    ra=-((-1*k(1)*y(1)*y(2))+(k(2)*y(3)*y(4))-(k(3)*y(1)*y(9))+(k(4)*y(6)*y(4)));
    rp=((-1*k(5)*y(5)*y(3))-(k(7)*y(5)*y(6))+(k(8)*y(6)));
    
    mtot=11.734;
    cp=2.06;
    Mmon=144.14;
    Mcat=405.1;
    Mcocat=186.34;
    Macid=144.22;
    Di=315.9; %in mm
    %equation 16
    density_cat=1200;
    density_cocat=820;
    density_acid=908.8;
    density_pla=k(17);
    
    % Dilution terms included
    
    rcat=-ra;
    rcocat=(-1*k(1)*y(1)*y(2))+(k(2)*y(3)*y(4))-(k(9)*y(2)*y(6))+(k(10)*y(3)*y(9));
    racid=ra;
    rmon=-rp;
    rini=(-1*k(5)*y(5)*y(3))+(k(1)*y(1)*y(2))-(k(2)*y(3)*y(4))+(k(9)*y(2)*y(6))-(k(10)*y(9)*y(3));
    rla0=(k(3)*y(9)*y(1))-(k(4)*y(6)*y(4))+(k(5)*y(5)*y(3))-(k(9)*y(6)*y(2))+(k(10)*y(9)*y(3));
    rla1=((k(3)*y(10)*y(1))-(k(4)*y(7)*y(4))+(k(5)*y(5)*y(3))+(k(7)*y(5)*y(6))-(k(8)*y(6))-(k(9)*y(7)*y(2))+ ...
        (k(10)*y(10)*y(3))-(k(11)*y(7)*y(9))+(k(12)*y(10)*y(6))-(k(13)*y(7)*(y(10)-y(9)))+(0.5*k(14)*y(6)*(y(11)-y(10)))-(k(15)*y(7)*((y(13)-y(12)))+(0.5*k(16)*y(6)*(y(14)-y(13)))-(0.5*k(20)*(y(8)-y(7)))));
    rla2=(k(3)*y(11)*y(1))-(k(4)*y(8)*y(4))+(k(5)*y(5)*y(3))+(k(7)*y(5)*((2*y(7))+y(6)))+(k(8)*(y(6)-(2*y(7))))- ...
        (k(9)*y(8)*y(2))+(k(10)*y(11)*y(3))-(k(11)*y(8)*y(9))+(k(12)*y(11)*y(6))+(0.33333*k(13)*y(6)*(y(7)-lam3))+ ...
        (k(14)*y(7)*(y(8)-y(7)))-(k(15)*y(8)*(y(10)-y(9)))+(0.16667*k(16)*y(6)*((2*mu3))-((3*y(11))+y(10)))-((k(23)*y(8)*(y(13)-y(12))))+(0.166*k(24)*y(6)*((2*gam3)-(3*y(14))+y(13)))-(0.1666*k(20)*((4*lam3)-(3*y(8))-y(7)));
    
    rmu0=(-1*k(3)*y(9)*y(1))+(k(4)*y(6)*y(4))+(k(9)*y(6)*y(2))-(k(10)*y(9)*y(3));
    rmu1=(-1*k(3)*y(10)*y(1))+(k(4)*y(7)*y(4))+(k(9)*y(7)*y(2))-(k(10)*y(10)*y(3))+(k(11)*y(7)*y(9))-(k(12)*y(10)*y(6))...
        +(k(15)*y(7)*(y(10)-y(9)))-(0.5*k(16)*y(6)*(y(11)-y(10)))-(0.5*k(20)*(y(11)-y(10)));
    rmu2=(-1*k(3)*y(11)*y(1))+(k(4)*y(8)*y(4))+(k(9)*y(8)*y(2))-(k(10)*y(11)*y(3))+(k(11)*y(8)*y(9))-(k(12)*y(11)*y(6))+ ...
        (k(15)*y(8)*(y(10)-y(9)))+(k(16)*y(7)*(y(11)-y(10)))+(0.16667*k(16)*y(6)*((-4*mu3)+(3*y(11))+y(10)))-(0.166*k(20)*((4*mu3)-(3*y(11))-y(10)));
    
    rga0=((k(20)*(y(7)-y(6)))+(k(21)*(y(10)-y(9))));
    rga1=(k(13)*y(7)*(y(13)-y(12))-(0.5*k(14)*y(6)*(y(14)-y(13)))-(k(20)*(y(14)-y(13)))...
            +(0.5*k(21)*(y(8)-y(7)))+(0.5*k(22)*(y(11)-y(10))));
    rga2=((k(13)*y(8)*(y(13)-y(12))+(k(14)*y(7)*(y(14)-y(13)))+(0.16666*k(15)*y(6)*((-4*gam3+(3*y(14)+y(13)))))-(0.333*k(20)*((4*gam3)-(3*y(14))-y(13))))+(0.1666*k(21)*((2*lam3)-(3*y(8))+y(7)))...
            +(0.1666*k(22)*((2*mu3)-(3*y(11))+y(10))));
    
    % dilution terms for 1-14
    dilution_1=rcat-(y(1)/y(16))*dy(16);
    dilution_2=rcocat-(y(2)/y(16))*dy(16);
    dilution_3=rini-(y(3)/y(16))*dy(16);
    dilution_4=racid-(y(4)/y(16))*dy(16);
    dilution_5=rmon-(y(5)/y(16))*dy(16);
    
    dilution_6=rla0-(y(6)/y(16))*dy(16);
    dilution_7=rla1-(y(7)/y(16))*dy(16);
    dilution_8=rla2-(y(8)/y(16))*dy(16);
    
    dilution_9=rmu0-(y(9)/y(16))*dy(16);
    dilution_10=rmu1-(y(10)/y(16))*dy(16);
    dilution_11=rmu2-(y(11)/y(16))*dy(16);
    
    dilution_12=rga0-(y(12)/y(16))*dy(16);
    dilution_13=rga1-(y(13)/y(16))*dy(16);
    dilution_14=rga2-(y(14)/y(16))*dy(16);
    %}
    
    a=rmon/k(17);
    b=(y(5)*y(16)*Mmon)/((k(17))^2);
    diff_mon=((-0.8462)/(1.110865+(7.391*10^-4*y(15)))^2);
    diff_pla=((-0.8462)/(1.110865+(7.391*10^-4*y(15)))^2);
    c=rcat/density_cat;
    d=rcocat/density_cocat;
    e=racid/density_acid;
    f=(1-(1/density_pla));
    g=(mtot-(((y(5)*Mmon)+(y(1)*Mcat)+(y(2)*Mcocat)+(y(4)*Macid))*y(16))/((density_pla)^2));
    
    dy(1)=(-1*k(1)*y(1)*y(2))+(k(2)*y(3)*y(4))-(k(3)*y(1)*y(9))+(k(4)*y(6)*y(4))+dilution_1; 
    dy(2)=(-1*k(1)*y(1)*y(2))+(k(2)*y(3)*y(4))-(k(9)*y(2)*y(6))+(k(10)*y(3)*y(9))+dilution_2;
    dy(3)=(-1*k(5)*y(5)*y(3))+(k(1)*y(1)*y(2))-(k(2)*y(3)*y(4))+(k(9)*y(2)*y(6))-(k(10)*y(9)*y(3))+dilution_3; % +(k(4)*y(6));
    dy(4)=(k(1)*y(1)*y(2))-(k(2)*y(3)*y(4))+(k(3)*y(1)*y(9))-(k(4)*y(6)*y(4))+dilution_4;
    dy(5)=(-1*k(5)*y(5)*y(3))-(k(7)*y(5)*y(6))+(k(8)*y(6))+dilution_5; 
    dy(6)=(k(3)*y(9)*y(1))-(k(4)*y(6)*y(4))+(k(5)*y(5)*y(3))-(k(9)*y(6)*y(2))+(k(10)*y(9)*y(3))+dilution_6;
    
    dy(7)=((k(3)*y(10)*y(1))-(k(4)*y(7)*y(4))+(k(5)*y(5)*y(3))+(k(7)*y(5)*y(6))-(k(8)*y(6))-(k(9)*y(7)*y(2))+ ...
        (k(10)*y(10)*y(3))-(k(11)*y(7)*y(9))+(k(12)*y(10)*y(6))-(k(13)*y(7)*(y(10)-y(9)))+(0.5*k(14)*y(6)*(y(11)-y(10)))-(k(15)*y(7)*((y(13)-y(12)))+(0.5*k(16)*y(6)*(y(14)-y(13)))-(0.5*k(20)*(y(8)-y(7)))))+dilution_7;
                                                                                                                                                                                                                                                                                        %mu3
    dy(8)=(k(3)*y(11)*y(1))-(k(4)*y(8)*y(4))+(k(5)*y(5)*y(3))+(k(7)*y(5)*((2*y(7))+y(6)))+(k(8)*(y(6)-(2*y(7))))- ...
        (k(9)*y(8)*y(2))+(k(10)*y(11)*y(3))-(k(11)*y(8)*y(9))+(k(12)*y(11)*y(6))+(0.33333*k(13)*y(6)*(y(7)-lam3))+ ...
        (k(14)*y(7)*(y(8)-y(7)))-(k(15)*y(8)*(y(10)-y(9)))+(0.16667*k(16)*y(6)*((2*mu3))-((3*y(11))+y(10)))-((k(23)*y(8)*(y(13)-y(12))))+(0.166*k(24)*y(6)*((2*gam3)-(3*y(14))+y(13)))-(0.1666*k(20)*((4*lam3)-(3*y(8))-y(7)))+dilution_8;
    
    
    dy(9)=(-1*k(3)*y(9)*y(1))+(k(4)*y(6)*y(4))+(k(9)*y(6)*y(2))-(k(10)*y(9)*y(3))+dilution_9;
    
    dy(10)=(-1*k(3)*y(10)*y(1))+(k(4)*y(7)*y(4))+(k(9)*y(7)*y(2))-(k(10)*y(10)*y(3))+(k(11)*y(7)*y(9))-(k(12)*y(10)*y(6))...
        +(k(15)*y(7)*(y(10)-y(9)))-(0.5*k(16)*y(6)*(y(11)-y(10)))-(0.5*k(20)*(y(11)-y(10)))+dilution_10;
                                                                                                                                                                                                                        
    dy(11)=(-1*k(3)*y(11)*y(1))+(k(4)*y(8)*y(4))+(k(9)*y(8)*y(2))-(k(10)*y(11)*y(3))+(k(11)*y(8)*y(9))-(k(12)*y(11)*y(6))+ ...
        (k(15)*y(8)*(y(10)-y(9)))+(k(16)*y(7)*(y(11)-y(10)))+(0.16667*k(16)*y(6)*((-4*mu3)+(3*y(11))+y(10)))-(0.166*k(20)*((4*mu3)-(3*y(11))-y(10)))+dilution_11;
    
    
    dy(12)=((k(20)*(y(7)-y(6)))+(k(21)*(y(10)-y(9)))+dilution_12);
    dy(13)=(k(13)*y(7)*(y(13)-y(12))-(0.5*k(14)*y(6)*(y(14)-y(13)))-(k(20)*(y(14)-y(13)))...
            +(0.5*k(21)*(y(8)-y(7)))+(0.5*k(22)*(y(11)-y(10)))+dilution_13);
    
    dy(14)=((k(13)*y(8)*(y(13)-y(12))+(k(14)*y(7)*(y(14)-y(13)))+(0.16666*k(15)*y(6)*((-4*gam3+(3*y(14)+y(13)))))-(0.333*k(20)*((4*gam3)-(3*y(14))-y(13))))+(0.1666*k(21)*((2*lam3)-(3*y(8))+y(7)))...
            +(0.1666*k(22)*((2*mu3)-(3*y(11))+y(10)))+dilution_14);
    
    dy(15)=(((-Hra*ra+(-Hrp)*rp)*y(16)))/(mtot*cp);  
    
    dy(16)=(((a-(b*diff_mon*dy(15)+c+d+e)*f)-(g*diff_pla*dy(15))));
    
    dy(17)=((4/(3.14*Di^2))*dy(16))*10^6;
  end

calling Code:

y0=[1 15 0 0 6000 0 0 0 0 0 0 0 0 0 140 10.121 185 ];
ts=[0 2];
[P,X]=ode15s(@adiabatic_batch,ts,y0);
 mw=144*(X(:,8)+X(:,11)+X(:,14))./(X(:,10)+(X(:,7)+X(:,13)));
 mn=144*(X(:,7)+X(:,10)+X(:,13))./(X(:,9)+X(:,6)+X(:,12));
 conv=1-(X(:,5)/y0(5));
 pdi=mw./mn ;
 Temp=X(:,15);
 plot(P,Temp,'-','LineWidth',2,'DisplayName','3771');
 hold on

[Rik]

This time I edited your question for you. Next time, please use the tools explained on this page to make your question more readable.

[Azeeth Kumar M]

Thank you so much,Rik.Since I am new to this community,I didn't have any idea about the tools.Thanks once again.