integration of solid oxide fuel cells and ... - Ea Energianalyse

6. CASES AND ECONOMICS
Data from Bangkok is shown in figure 6.3 to illustrate the climate of
the middle part the country. The relative humidity varies a lot and is
more extreme than in the Seychelles: The relative humidity is up to 94% 2 ,
and the temperature is normally in the range of 20-35 ◦ C but can be as
high as 41 ◦ C.
Figure 6.3: Weather data for Bangkok, Thailand. Average condition. Table taken from [3].
Keeping these climate data in mind, the COP of the system (blue
line with round dots in figure 6.4A) shows that it is not sufficient to
use a desorber temperature (DES2) of 150 ◦ C since COP ABS,f uel decreases
drastically at about 30 ◦ C. Thus it has been necessary to increase T DES2 3 in
order to extend the range of the ambient temperature at which the system
can operate (blue line with triangular markers in figure 6.4A). When the
temperature of DES2 is increased, the ambient temperature can be up to
about 40 ◦ C, but the high ambient temperature does significantly decrease
COP ABS .
The biggest problem though is that DES2 is exposed to a temperature
of up to 190 ◦ C which is much higher than the recommended maximum
temperature of 150 ◦ C according to [27] (see brown curve market with
triangles in figure 6.4B). Thus it should not be expected that a standard
absorption unit can operate under this high temperature due to corrosion
problems.
2 The most extreme values of the humidity is likely to be caused by fluctuating
temperature, so it is assumed that the humidity is not above 0,9 during daytime.
3 The desorber temperature of DES1 has been changed as well since its optimum
value depends on the temperature of DES2.
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