Set up of the test facility
One aim of the newly developed all-in-one test facility is to combine all three test methods in a single test facility. This test facility must be able to fulfil all requirements and qualifications resulting from the above mentioned standards.
The housing of the test facility is a conventional 20 foot office container. In this container the hydraulics of the temperature unit as well as the measuring equipment and the data logging instruments are located. In order to operate the facility independent from a cooling network, a chiller combined with a 600 litre cold water store is installed. With the exception of the chiller, all com-
ponents are located inside the container. Figure 1 shows the schematic layout of the major components.
The facility is designed in such a way that it allows for parallel testing of
• 4 collectors (according to EN 12975 / ISO 9806) or
• 4 systems according to ISO 9495-2 (CSTG-method) or
• 2 systems according to ISO 9495-5 (DST-method)
To realise these different test configurations, the hydraulic arrangement consists of one main loop that can be divided into six smaller loops by using several valves. These six loops are required for testing two solar thermal systems according to the DST-method at the same time. The hydraulics for testing according to ISO 9459-2 and ISO 9806 / EN 12975 consist of only one hydraulic loop, which can be used to test four systems (CSTG-method) or four collectors simultaneously. In figure 2, the layout of the complete hydraulic arrangement is shown.
On the left side of the diagram the four connections for testing the systems (ISO 9459-2, CSTG - method) or for the collectors (EN 12975) are located (1-4). For the DST-method (ISO 9459-5), connections for two collectors (1-2) including the two necessary connections to the solar collector loop (DST-solar 1-2) are depicted. The middle part of the hydraulic circuit is solely related to the DST-method, since there are the connections for the thermal auxiliary heating loops (DST-aux 1-2) and the storage tanks (DST-tap 1-2) of the two systems to be tested. The first heat exchanger (HX1) in flow direction offers the possibility to connect an optional external cooling net. If this is not available, the heat will be removed via the second heat exchanger (HX2), which is on the secondary side connected to the cold water store of the test facility. The cooling circuit also supplies the air conditioning unit inside the container test facility with cold water. On the right hand side of the vertical line, which symbolizes the wall of the container, the chiller is located.
This chiller is positioned outside the container because this allows a better supply of fresh air to the refrigerant condenser and reduces the noise level inside the container test facility. Figure 3 shows the chiller connected to the container of the test facility.
All hydraulic connections to the equipment being tested are located outside the container and are realized with conventional 1 inch screw fittings, countersunk into the container walls. In figure 4 the connections to the collectors / systems being tested are shown.