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

C H A P T E R
4
SYSTEM DESCRIPTION
4.1 General
The components described in the previous chapter have been assembled
in order to make a model of SOFC system integrated with an absorption
cooling unit, see figure 4.1. The system can be divided into subsystems:
SOFC subsystem, absorption subsystem and cooling tower.
The absorption cycle can be either a Singe Stage or a Double Stage. In
addition it is possible to supply the double stage cycle with heat input in
two different points - this is called Dual Heat. Enlarged layout diagrams
of all three system configurations are seen in appendix G page 293.
Each of the subsystems will be described in the following sections as
well as the three different system configurations. Also the value of the
most important parameters and assumptions will be stated.
In general all heat losses of the components to the surroundings are
assumed to be zero 1 .
The closest approach temperature difference for heat exchangers
is estimated to be 5 ◦ C for liquid-liquid, 10 ◦ C for Condensers (which
are liquid-liquid/gas), 15 ◦ C for liquid-gas and 25 ◦ C for gas-gas heat
exchangers.
The fluid in the external heat transfer circuits is water and the
1 The wet/dry cooling towers are an exception - their purpose is to reject heat to the
surroundings.
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