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

5. SIMULATION AND RESULTS
5.2 System configurations
In the previous section with the single cycle mostly COP ABS was used
(i.e. the ratio of cooling power and high temperature heat input into the
absorption cycle). This was typically around of 0,8 for Single Stage and
around 1,4 for Double Stage.
In the following sections primarily COP ABS,f uel will be used since this
shows how much cooling power the system provides per kW of fuel into
the system (which remains constant at 100kW). This is done because the
important thing for system optimization is how much cooling the system
produces in the end (it doesn’t help that COP ABS is increased by
a certain tweak if the heat flow into the absorption unit is at the same
time reduced by a greater factor, so that the cooling power as a total
drops). COP ABS,f uel will typically be around 0,4-0,5 corresponding to
40kW-50kW of cooling per 100kW of fuel input.
Three different aspects will be examined regarding the overall system
configuration:
• Single Stage (SS) vs Double Stage (DS) vs Double Stage with Dual
Heat (DH).
• Air Preheating (AP) vs No Air Preheat (-).
• Dry Cooling Tower (d) vs Wet Cooling Tower (w).
First SS, DS, and DH will be compared for AP and ”-AP” (all using a wet
cooling tower 2 ). Once the best of these six combinations has been chosen,
the two types of cooling towers will be compared. A figure with all 12
combinations can be seen in appendix E.1.1 (page 276).
For each figure in the following, the color convention will be as follows:
Blue represents COP ABS,f uel : the amount of cooling power generated
per fuel input (kW/kW).
Black represents η el ,sys,net : the amount of net electricity generated per
fuel input (kW/kW).
2 The same tendencies are observed when the dry tower is used, just with
COP ABS,f uel at a lower level
114