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

4. SYSTEM DESCRIPTION
4.6 Cooling Tower
28
WGHEX
3
23
MIXR
1
50
32
DES1
31
27
Domestic Hot Water
24
Saturated air
47
Flue gas, out
52
35
COND1
36
51
MIXL
1
59
82
60
61
SHEX
1
57
56
VA1
VB1
PUMP
1
Water add
38
TOWER
46
53
49
EVAP
48
54
62
36
ABSO
37
55
39
37
FAN
45
Atmospheric air
Chilled Water
Figure 4.6: Diagram of cooling system and hot water production (zoom of figure 4.1). The
cooling tower removes waste heat from the absorber (ABSO) and the condenser (COND1). The
remaining heat in the exhaust gas is used for hot water production.
As described in section 4.3, heat must be removed from the condenser
(COND1) and the absorber (ABSO) by a heat transferring fluid (water).
It has been decided to connect COND1 and ABSO in series. According
to Scandinavian Energy Group [27] the condenser is normally ”before” the
absorber for cooling units (for heat pumps it is always the opposite). This
corresponds to the series connection of COND1 and ABSO (point 35, 36
and 37) in figure 4.6.
The temperature difference of the Tower inlet (point 37) and outlet
(point 39) is estimated to be ∆T c,TOW ER1 = 5 ◦ C. In praxis this is
controlled by the water mass flow in the external circuit. The COP
generally increases if ∆T c,TOW ER1 is reduced (the absorber and condenser
becomes colder), but since the water flow increases, pumping work
and component geometry is enlarged which requires more energy and
increases the price of the condenser and absorber.
The water is cooled by the ambient air (at T amb ) which enters the
tower at point 45, is pressurized by the FAN (point 46) and then
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