A widespread type of collector, which collects solar energy in a non-concentrating way, is the flat collector. The absorber is a selectively coated metal sheet that conducts heat well. The flat collector is mainly used for hot water preparation and heating support. It represents a balanced compromise between simple, cost-effective construction and efficiency.
HL 313 can be used to demonstrate the principal aspects of solar thermal domestic water heating in a system with components used in real world applications. Radiant energy is converted into heat in a commercially available flat collector and transferred to a heat transfer fluid in the solar circuit. The heat then gets into the hot water circuit via a heat exchanger. A solar controller controls the pumps for the hot water and solar circuits. The solar circuit is protected by an expansion tank and a safety valve. The trainer has been designed so that it is possible to carry out a complete preheating as part of a practical experiment.
The temperatures in the storage tank, at the outlet from and the inlet to the collector are measured, as is the flow in the solar circuit. The measured values are recorded via the integrated data logger. Additionally, as in practice, the temperatures of the inlet and return are displayed on the solar circulation station.
The solar controller is operated via an integrated router. The user interface can be displayed on any number of terminals via a web browser. Different user levels with different functions can be selected. Access to recorded measured values is possible on Windows-based end devices via WLAN with integrated router or LAN connection to the customer’s own network. An additional producer software of the solar controller is supplied for this purpose.
In order to ensure there is sufficient illuminance, the system should be operated with solar radiation or the optionally available HL 313.01 Artificial light source.