Simulation of a solar domestic water heating system, with different collector efficiences and different volumen storage tanks

Abstract

This paper shows the modeling and dynamic simulation, of a domestic solar water heating installation. The results of simulations performed on an annual basis for a solar system, operated in Santander (Spain), which provides hot water for a family (four persons) are presented. The installation consists in a solar flat collector, a water storage tank, a source of auxiliary energy, and a device for blending water. The mathematical model is used to evaluate the annual variation of the solar fraction respect to the volume of the storage tank, demand hot water temperature required, difference of this temperature and preset storage tank water temperature, and consumption profile of the domestic hot water demand. The results for a number of designs with different storage tank volumes, show that the systems with greater volume yield higher solar fraction values. However, when a larger storage tank volume is used, the solar fraction is less sensitive to a variation of these operation parameters. The results of this simulation may be used to design a solar collector system.