Negative Total heat flux at inlet
 

Hi All!

I'm not familiar in heat transfer field. I'm studying fluidized bed reactor with transient study.

In my system, solid particle was patched at the bottom of reactor. Then, i continuously fed gas and solid with 343K temperature. I also initialized this system with 375K.

After starting calculation, i found that total heat flux of gas and solid at feed inlet are negative value. As my understanding, total heat flux should be equal to mass flow rate*heat capacity*(T in-T ref) which is certainly positive value. i also checked that mass flow rate of gas and solid at inlet are positive value.

I don't know why total heat flux is negative value at inlet.:confused::confused:

Please anyone advice me to solve this problem.
Thank you so much.

Best regard
Tleja