Validation of a dynamic model for unglazed collectors including condensation. Application for standardized testing and simulation in TRNSYS and IDA

An improved unglazed collector model has been validated for use in TRNSYS and IDA and also for future extension of the EN12975 collector test standard. The basic model is the same as used in the EN12975 test standard in the quasi dynamic performance test method (QDT). In this case with the addition of a condensation term that can handle the operation of unglazed collectors below the dew point of the air. This is very desirable for simulation of recharging of ground source energy systems and direct operation of unglazed collectors together with a heat pump. The basic idea is to have a direct connection between collector testing and system simulation by using the same dynamic model and parameters during testing and simulation. The model together with the parameters will be validated in each test in this way. This work describes the method applied to an unglazed collector operating partly below the dew point under real dynamic weather conditions, for a long period during the autumn 2010. The validation results also show that the model can handle operation of such a collector during the night. This is a common mode of operation for this collector type in a real system.