Modelling bulk water temperature in integrated collector storage systems

Abstract

A simple low cost Integrated Collector Storage Solar Water Heater (ICS-SWH) was proposed for simulation in Scottish weather conditions. The system takes the form of a rectangular-shaped design incorporating the solar collector and storage tank into a single unit and the simplicity of construction and installation make this type of SWH a popular choice of solar water heater. A 3-month experimental and numerical study on the ICS-SWH was undertaken in order to compare the results with a newly developed macro model. Improvements were incorporated into the macro model by differentiating non-finned and finned collectors. The macro model was able to compare the water bulk temperature variation in different SWH collector material, with or without fins, internal temperature and external weather conditions for a given aspect ratio. Numerical results obtained by this new tool were found to be in close agreement with the experimental data. Practical applications: Direct comparison of measured system performances is relatively straight forward; however, predicting the performance of an ICS-SWH at another location or with a different installation configuration is more challenging. A model able to predict water temperature in ICS-SWH would be a useful tool to allow any user to predict the performance of the installed SWH, depending on the orientation and location. Builders could use such a tool to demonstrate the performance of the ICS-SWH and the benefit of such installation.