Experiences with mobile, stand-alone test facility for solar thermal collectors and systems

Abstract

Paper presented at the 6th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 30 June - 2 July, 2008.Solar thermal technology is a booming market. As a result, a wide range of solar thermal collectors and systems are produced by numerous manufacturers all over the world. In order to assess thermal performance, manufacturing quality, safety of operation and to identify potential for further improvement, accurate testing of solar thermal collectors and thermal solar systems is required. Standardized testing procedures for solar thermal collectors are e.g. specified in the European Standard EN 12975 or the international standard ISO 9806 and for solar thermal systems in the South African Standards SANS 1370 (Mechanical tests) and SANS 6211-1 (Thermal tests) as well as in the international standards ISO 9459-2 (CSTG-method) and ISO 9495-5 (DST-method). In order to secure a growing market for solar thermal products in South Africa and its neighbouring countries, it is essential to establish a solar thermal test institute as a service provider for manufactures and suppliers in the Southern African area. For this purpose, a turn-key test facility for solar thermal collectors and systems was purchased from the German company Solarund Wärmetechnik Stuttgart (SWT). SWT is a spin-off company from the Institute for Thermodynamics and Thermal Engineering (ITW) of the University of Stuttgart. ITW has been working in the solar thermal field for more than 30 years and is operating the “Research and Test Centre for Thermal Solar Systems” (TSZ). The TZS is the largest solar test centre in Europe. Hence, very substantial experience related to testing and the construction of test facilities has been gained at ITW and SWT. The test facility for the South African Bureau of Standards (SABS) is part of a project financed by the Central Energy Fund (CEF) and the United Nations Development Program (UNDP). The facility was manufactured and instrumented by SWT based on a standard office container as a turn-key product. Before the test facility arrived from Germany, two staff members of SABS were trained for one week at SWT in Stuttgart, Germany. An additional training program took place onsite, after the test facility had been set-up and commissioned in Pretoria. The initial operation was performed together with an expert from SWT. After shipment to South Africa the test facility could be taken into operation within a few days at the South African Bureau of Standards (SABS), located in Pretoria. The South African Bureau of Standards has been working with the mobile, standalone test facility since the beginning of 2007 and has already tested several systems according to SANS 6211-1. To-date, the experiences gained with the mobile, stand-alone test facility are very good. It operates without notable problems and delivers reliable and accurate results. The paper describes the principle set-up of the test facility as well as the experience gained by SABS.