Environmental Engineering Reference
In-Depth Information
Temperature
•
Both Modes analysis
: this is the dominant factor. There are two different trends,
firstly, heating one, form levels 1 to 3, where latent heat decreases and secondly,
cooling one from level 4, where latent heat increases.
•
Heating Mode
: evaporation is governed by the water vapour partial pressure
between the tubes surface and the primary airstream. The specific humidity levels of
the dates (See Tables 6-9) are closed, under these conditions, the heat exchanged is
mainly sensible heat, within this situation the saturation vapour pressure enables
water evaporation, (although temperature rises the corresponding relative humidity is
lower). Level 4 presents a different trend in comparison with levels 1 to 3).
•
Cooling Mode
: The dates present low relative humidity values and high
temperatures, which corresponds to large evaporative capacity, whilst for lower
temperature levels (heating mode) the relative humidity levels associated are higher,
which corresponds to low evaporation capacity. Even next to saturation,
condensation conditions could occur, diminishing the latent heat exchanged.
VxT interaction
•
Heating Mode
: When analyzing the data in detail, it is observed that T1 for V2
presents an anomalous value, lower than expected, fact which motivates the
intersection. Level 4 presents a different behaviour similar to the one observed in
cooling mode.
•
Cooling Mode
: in this case an interaction occurs. When increasing airflow and
temperatures together with lower relative humidity levels, the latent heat recovered
rises. As previously discussed, this behaviour is limited by the maximum airflow
(V2).
T
OTAL
H
EAT
R
ECOVERED
Due to the fact that the combined system mostly reproduces the evaporative cooler device
behaviour (see Figure 32). The results offered corresponds to the evaporative cooler device.
The ANOVA also corroborates this fact. (See Table 30).
Evaporative Cooler
In this subsection a detailed analysis for the evaporative cooling system was carried out.
Firstly, the corresponding results for both working modes are shown ( See Figure 33 and
36 and Tables 31-33), and secondly, these results are studied separately for heating mode
(See Figure 34 and Table 34 ) and cooling mode (See Figure 35 and Table 34).
