3. PANEL DESIGN
350 = 5.5 * 3.96 * (Ti – 30)
Ti = 46
◦
C
For the same panel, calculate the internal temperature for an installed power of 1000W.
Qs = k * A * (Ti – Te)
1000 = 5.5 * 3.96 * (Ti – 30)
Ti = 76
◦
C
In this case, the temperature has exceeded the equipment operation limit (60
◦
C), and a solution must be provided to
exchange the exceeding heat. The installed power limit for the internal temperature limit of 60
◦
C is given by:
Qs = k * A * (Ti – Te)
Qs = 5.5 * 3.96 * (60 – 30)
Qs = 653W, this being the limit, the exceeding 347W (1000W – 653W) must be dealt with by an air conditioned device,
for instance.
ATTENTION:
In the previous calculation, it must be observed that the internal temperature is always the
average and if there’s no forced ventilation inside the panel, the temperature of the upper
part will be higher than the base, and concentrated heating points may appear. The due
security coefficient must be taken for each case.
Figure 33: Example of Heat Flow – Closed Installation
A much higher heat dissipation, comparing with the one obtained previously, can be achieved if the room heat exchange is
allowed. The ventilation is often used introducing ventilation gaps on the side surfaces, door or on the back of the panel. This
will evidently reduce the panel protection degree (IP).
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