Casestudie Breakdown prediction Contell PILOT - Transumo

the specified value, it works very accurately because total deviation is less than 2°C
within the displayed time of five days. On the other hand, the graph contains a trend.
Within four days the daily mean increased more than half a degree. An event like this
has to be recognized and surveyed, when classifying the system’s behavior.
Figure 2-4: Temperature Sequence of a -80°C Active Freezer [DEMO06]
Figure 2-5 shows the behavior of a -80°C passive freezer. This one behaves totally
different. The data does not contain a trend but oscillates much more than the one
above. Furthermore, -80°C is never reached and total deviation is more than 8°C, so
that temperature exceeds -70°C regularly.
Figure 2-6 shows another kind of freezer. The red lines signalize door openings. The
special thing about that device is that it needs a regeneration cycle every few hours
due to technical reasons. Compared to the previous datasets, the oscillation is much
higher and the shape of the graph is more irregular. But as this is normal behavior for
this kind of freezer, it should be classified as OK.
2.2.4 Behavior in Practice
As mentioned at the beginning of this section, the exemplified temperature
sequences originate from the Contell/IKS demo system so far. Since these monitored
cooling devices are empty and not in use, they are not externally influenced by users.
In practice, a cooling device can be influenced by a large quantity of variables. 3
3 See section 2.4.2 for details
7