Change in the number of particles in a reactor with equal inlet and outlet particle volume flow rates

Dear developers, my model sets the volume flow rate of chemical particles equal to that of the two imports (5.6818e-07m^3/s for the export and 2.8409e-07m^3/s for both imports). It is found that the number of chemical particles has a great change after 50s operation, and after adding 20% inert particles (chemical particle volume flow rate remains unchanged), the change trend of chemical particle number under two working conditions is not consistent, as shown in the figure below:
image
At the same time, when the sensible heat of each time step of all particles is counted, it is found that it is not equal to the sum of several heat transfer paths (thermal conductivity, convection, radiation, reaction heat), and there is a deviation of 2% to 3%. The following is my case, I hope you developers can help me,thank you!
U_0.3_1150C.zip (3.7 MB)