An Improved Dynamic Solar Collector Model Including Condensation and Asymmetric Incidence Angle Modifiers
Abstract
For simulation of solar + heat pump systems a dynamic collector model is needed that can handle operation below the dew point of the ambient air (condensation). For some collectors also complex incidence angle behaviour for beam radiation and more complicated acceptance of diffuse radiation has to be handled. The dynamic collector model from the EN12975 collector test standard is used as basis. The TRNSYS 16 simulation model is written so that collector parameters derived from an EN12975 test, can be used directly without conversion. In case of collectors that face condensation energy flows an additional parameter/term is introduced to the collector model and test procedure in EN12975. The paper will describe the model and also proposals for adjustment of the test procedure to derive the new parameters from a standard test. Most of the individual parts of this work has been developed and published during a 33 year period based on international cooperation within the IEA SH&C programme in Task III, VI, VIII, 14, 26 and 32. 1. Introduction Dynamic solar collector modelling under real weather conditions is complicated. There are many second and third order effects present in the collector energy balance. To the authors experience it is most important to have the optical modelling as close to reality as possible. .