Model description

A model of a solar heating plant is built in TRNSYS. The collector array consists of 100 rows where the distance between the rows is assumed to be so large that the shadows between the rows have negligible influence on the collector performance. The energy consumption of a town is defined by a water mass flow rate, a return temperature and a flow temperature of 80°C.

If the temperature from the solar heat

exchanger is above 80°C the temperature is mixed down to 80°C with at three-way valve.

If the temperature from the solar heat

exchanger is below 80°C, an auxiliary boiler plant heats up the district heating water to 80°C.

An illustration of the TRNSYS model can be seen in Fig. 7 and Fig. 8 shows the mass flow rate and a flow and return temperature through out the year for the district heating net of the town. The annual heat consumption of the town is about 32500 MWh.

The collector performance is investigated for two locations:

• Copenhagen, Denmark, lat. 56°N, yearly average ambient temperature: 7.8°C. Weather data: DRY (Lund H. (1995). ).

• Uummannaq, Greenland, lat. 71 °N, yearly average ambient temperature: -4.2°C. Weather data: TRY (Kragh J. et al (2002). ).