Software for designing solar water heating systems

This paper presents a complete development of software for sizing small solar water heating systems. The application framework was developed using the MATLAB platform, and its algorithm was structured to minimize the user intervention. The software was developed using consolidated methodologies and practices relationships, aiming at the technical and economical project optimization. The used project methodologies were the F-Chart and Brazilian Technical Standards (NBR-15569), together with an economic analysis. All of them are detailed in this work. The database was built using commercial equipment performance data, from the official tests of the Brazilian Labeling Program, and meteorological data, from the Brazilian Solarimetric Atlas and Agronomic Institute of Paraná. The developed software allows the sizing of natural and forced circulation systems, composed of flat plate collectors or evacuated collectors type U, horizontal thermal storage tank and auxiliary power supply (electric or gas). It also allows the user to modify the input parameters at any time, making possible to simulate different situations and find the best technical and economical solution. An example of the solar system design is also presented and discussed.