Temperature Control Systems
In this section the control of temperature is to be discussed. Again only simple feedback loops are considered.
To change the temperature of something it is necessary to add or take away energy. This can be achieved in one of two ways.
- Transfer energy indirectly, using a second stream, through coils, tubes, jackets etc. The second stream could be, for example, steam, cooling water, another process stream or even a source of power as in an electric element.
- Mix in a second stream directly. This stream will have a different energy content from the original.
There are advantages and disadvantages for both methods. With the first there is the problem of transferring heat through the walls of the ‘coil’. In the second the energy is absorbed directly but with the additional problem of increased flowrate/volume.
Diagrams of these alternative schemes can be found below.
