Energy Transferred between the System and Surroundings

Tlie transfer of energy between tlie system and its suiToundings involves 

From the energy balanee Equation 6-12, the rate at whieh heat is absorbed by the surrounding into system Q is defined as  

Q = U A AT where A = heat transfer area of the heating or eooling eoil, m  

AT = temperature differenee between the heat transfer fluid and reaetion mixture, K 

In many eases, the heat flow (Q) to the reaetor is given in terms of the overall heat transfer eoeffieient U, the heat exehange area A, and the differenee between the ambient temperature, T, and the reaetion temperature, T. For a eontinuous flow stirred tank reaetor (CFSTR) in whieh both fluid temperatures (i.e., inside and outside the exehanger) are eonstant (e.g., eondensing steam), Q is expressed as 

The transfer of energy between the system and its surroundings involves 

U = overall heat transfer coefficient, J/m2 s K or W/m2K AT = temperature difference between the heat transfer fluid and reaction mixture, K 

If the fluid inside the heat exchanger tubes enters the CFSTR at a temperature Tal and leaves at a temperature Ta2, and the temperature inside the CFSTR is spatially uniform at temperature T, then the heat flow Q is expressed to the CFSTR by 

---

Work can be defined as the energy transferred between the system and surroundings. It is often expressed as a vector force acting through a vector displacement on the system boundaries ... 

---