Experimental Case Study - Design for Micro-Combined Cooling, Heating and Power Systems - page 372

Fig. 22 Stirling heat recuperation and protection hydraulic circuit

of thus maintaining the ef ciency of the Stirling engine. Circuit CH7 is placed

inside of the residence. Circuit CH8 has heat exchanger (HE 1 ) located inside of the
residence while the re-cooler is located outside. The thermal load is represented by
a heat sink,

fitted outside the system, which has the role of reducing the temperature
of the thermal agent to 45 C. The heat sink is cooled through forced convection

with a ventilator, so as to dissipate the heat

°

flux. Figure 22 presents the position of
the CH7 and CH8 circuits in the functional scheme of the system.
Circuits of hot water from ST panel to heat storage (CH9.1 and CH9.2)
Hydraulic circuit for obtaining heat from solar energy and storing it in the hot
water tank (CH9) has six solar panels of the direct

flow type (Fig. 23 ).
Placing the solar panels on the roof of the building was done according to the
available space; that is why two groups were formed, one of four panels and one of
two panels. Each group has its own pumping group. The CH9.1 and CH9.2 circuits
are united into a single circuit which goes to the inferior coil of the hot water tank.
The hydraulic circuit is characterized by the use of a soft water solution and mono-
ethylene glycol as thermal agent, so that the normal liquid water use limits increase
in the range of negative temperatures (during winter), but also in the range of
temperatures exceeding 100 ° C (during summer).

Circuit of DHW (CH10)
The DHW circuit is fuelled with energy from the DHW tank. The amount of
water is suf

cient for the daily consumption of the residence.
This water is heated through conduction from the water of the hot water tank.
The continuous refreshing of the water in the DHW tank presupposes resolving the