Development of Test Facilities for Solar Thermal Collectors and Systems
D. Bestenlehner[7], H. Widlroither[8], H. Drtick1, S. Fischer1, H. Mtiller-Steinhagen1
1Solar- und Warmetechnik Stuttgart (SWT)
Pfaffenwaldring 6, 70550 Stuttgart, Germany
Tel.: +49711 / 685-60155, Fax: +49711 / 685-63242
Email: bestenlehner@swt-technologie. de; drueck@swt-technologie. de
Internet: www. swt-technologie. de
2Fraunhofer-Institute for Industrial Engineering (IAO)
Nobelstrasse 12, 70569 Stuttgart, Germany
Email: harald. widlroither@iao. fraunhofer. de
Abstract
As a consequence of the booming solar thermal business, a considerable number of new solar thermal products, such as solar thermal collectors or complete systems, are entering the market. For the determination of the thermal performance and to ensure the durability and reliability of these solar products, testing is an important aspect.
In order ensure comparable and representative results, tests of solar thermal products are carried out according to well established procedures. Such test procedures are specified e. g. in the European Standard EN 12975 or ISO 9806 for solar thermal collectors and in the standard series ISO 9459 for solar thermal systems.
In order to perform the tests according to the above-mentioned standards, test laboratories and manufacturers require appropriate test facilities. Depending on the type of test, separate test facilities are used. These test facilities most often differ significantly, depending on the components to be tested. As a consequence for test laboratories and manufactures, the number of test facilities increases if different products, such as solar thermal collectors and complete factory made solar domestic hot water systems, shall be tested. The growing number of individual test facilities results in relatively high investment costs and leads to significant operational costs e. g. for maintenance and calibration of sensors.
One possibility to overcome these problems and to reduce the number of different test facilities is to combine identical functions that are required for testing different products into only one multifunctional test facility.
For determination of the thermal performance of either a complete solar thermal system or only the solar collector, two different test facilities are typically used. Taking into account the two different ways to determine the thermal performance of a solar domestic hot water system (so-called CSTG1 -method and DST2 - method) even three different test facilities may
be required. To minimize the amount of hardware and the required investment capital as well as operational costs, a so-called three-in-one test facility was developed by SWT- Technologie, Germany.
This mobile, stand-alone solar thermal collector and system test facility is a complete test facility for the determination of the thermal performance of solar thermal systems according to standards ISO 9459-2 (CSTG-method), ISO 9459-5 (DST-method) and the thermal performance of solar collectors according to standards EN 12975 or ISO 9806 respectively. Due to this three-in-one approach, substantial investment costs for construction and operational costs for maintenance of three different solar test facilities can be saved by the test laboratory or manufacturer respectively.
Since tests are specific to certain characteristics or properties of solar thermal systems and their components, it is obvious that not all possibly required tests can be performed with only a single test facility. Hence additional test facilities are required e. g. in order to perform durability and reliability tests of solar collectors.
Testing of solar thermal collectors and systems is required in order to asses the thermal performance and the quality of these products. This is especially necessary since solar thermal technology is a booming market and a wide range of solar collectors and systems are produced by numerous manufacturers all over the world.
Well established test procedures for solar collectors are specified in the European Standard EN 12975 or the international standard ISO 9806, and for solar thermal systems in ISO 9459-2 (CSTG-method) and ISO 9459-5 (DST-method).
In order to perform the tests specified in these standards, each test laboratory or manufacturer requires appropriate test facilities. Usually separate test facilities are used for collector and system testing. Typically, these test facilities are individually designed and installed at a specific location.
