Heat Exchangers Recuperators and Regenerators

A serious problem of heat exchangers is fouling, for example, biological debris enter the heat exchanger via cooling water from rivers or sea and build layers that decrease the heat transfer. Chemical deposits such as calcium carbonate may also be formed, and therefore heat exchangers must be cleaned periodically, for example, by acid or bullet cleaning. 

The temperature in both fluids changes along the local position of a heat exchanger. To account for this, a logarithmic mean temperature difference ATin mean (Topic 3.3.1) is uscd  

The fluids are heated or cooled, and the heat flux and the temperature differences are linked by the following energy balance (if heat losses to the surrounding 

the temperature difference in both fluids is identical, if the terms mj are equal. 

Topic 3.3.1 Logarithmic mean temperature difference in a heat exchanger 

---