High energy Residual
 

I modeled finned tube heat exchanger as shown in Fig.


http://cdn.imghack.se/images/1dc905e...12ae2a57bc.png

The problem, after 20 iterations the error start to increase and continuous until 1e-01 as shown in Fig.

http://cdn.imghack.se/images/3568c45...d2eb6d58a2.png

Help me please