temperature variation by time

Hi, i m new on matlab. i have an algorithm, i want to put this in matlab to generate a graph, but i dont know how to write the code ( a picture of algorithm is attached)

these are values of parameters : U=220; Un= 230; Pn=2000; densitate =1; c= 837; V = 12; tf = 180; t0=20; teta0=20;

i did something like this :

 U=220; Un= 230; Pn=2000; densitate =1; calduraSpecifica= 837; volum = 12; tf = 180; t0=20; teta0=20;
 
 
 t= t0; 
 teta = teta0;
 
 while U>Un
     K=(U/Un)^2*Pn/(densitate*volum*calduraSpecifica);
     
     while t<tf
         t= t+deltat;
         teta=K*t+teta0;
     end
     U=U+deltat;
 end