
      LARTEC11.COM

  5=DIAGRAM
 
 Diagram about efficiency and heat losses. 
 For all plane thermal solar collectors.
 
 Solar collectors have their maximal efficiency (Eta0) when the collector 
 medium temperature is equal to ambient (surrounding) temp.
 If you use a negative collector medium temperature you could encounter even 
 higher effect rate, but that has no interest here.

 Normally it ranges from 60 % up to 83 %, which is the top figure I know about.
 Theoretically it could be more, as the main obstacle is the glass shield
 transparency and reflection. The absorbing adhesive we used, which was
 "Maxorb" could have 99 % absorbing rate, but black chrome on copper (Cu) has
 proven the same rate.

 When collector heats up, heat losses arises and eventually equals the 
 absorbed heat. At this time there is no net energy out of the collector, and
 you have reached the end of diagram.

 This arc shaped diagram is depended on three factors:
 Eta0 = The above mentioned efficiency.

 K0 = The solar collector specific heat loss coefficient , which normally 
 ranges from less than 1 W/m2*C (Watt per square meter times C degree) 
 for vaccum tubes, and up to 20 for pool collectors. Our figure was 3.9 W/m2*C.

 K1 = The heat dependent heat loss koefficient (second order), is normally
 0.01 to 0.03. Our figure was 0.027 W/m2*C*C.

 The Algorithm used is written on the screen.

 This program simply calculate and writes down that equation at different
 variables of heat.

 Stig 
