Energy balances with cooling coils

These configurations are essentially two reactors connected by the heat exchange area A, and we will consider this in more detail in a later chapter in connection with multiphase reactors. We do not need to write a species balance on the coolant, but the energy balance in the jacket or cooling coil is exactly the same as for the reactor except that we omit the reaction generation term. 

Figure 6-15 Sketches of a CSTR with cooling either through a jacket (left) or a cooling coil (right). A separate energy balance must be solved for the coolant temperature if the temperature of the cooling fluid Tq is not constant and equal to the coolant feed temperature Tio-...

The obvious way to heat or cool a chemical reactor is by heat exchange through a wall, either by an external jacket or with a cooling or heating coil. As we discussed previously, the coolant energy balance must be solved along with the reactor energy balance to determine temperatures and heat loads. 

Sizing the reactor implies calculating, besides reactor volume, the heat-transfer area of the cooling coils and of the FEHE. We assume constant volumetric flows and coolant temperature, and neglect the temperature dependence of the reaction heat and physical properties. With these assumptions, the mathematical model of the reactor which includes the energy balance is given by ... 

---