Water Heating System Using Concentrated Solar Radiation

The article presents the results of an applied study aimed at creating a fairly simple, inexpensive and at the same time effective domestic solar water heating unit (SWHU) with the concentration of solar energy. A feature of such a SWHU is its relatively small dimensions and the possibility of installation in accessible conditions: on the walls, roofs or balconies of both individual houses and apartment buildings. The task of the work was to develop the main elements of the SWHS design, their manufacture and conduct experimental studies on the efficiency of the entire system in field conditions. An important unit in such a system is a solar energy concentrator (SEC), which, thanks to the use of a mirror or lens, collects solar radiation from a relatively large area and focuses it on a small surface, where a thermal collector of a special design is placed. Due to the constant tracking of the SEC by the sun and the many times greater intensity of solar radiation, fairly high temperatures are achieved in the collector throughout the entire sunny day, which makes it possible to increase the efficiency of solar energy use.
A household SWHU with SEC was created based on a parabolic dish of a satellite antenna with a two-axis electric drive system for pointing at the sun, a hydraulic heat transfer system from the thermal collector to the storage tank and a low-power autonomous electrical power supply system based on a photovoltaic solar panel, which is characterized by compactness, the ability to be fixed on a wall of a house, and the low cost of the components used.
Preliminary experimental studies on the efficiency of the installation of the proposed design showed its rather low efficiency, due, first of all, to a number of shortcomings in the design of the thermal collector, which are planned to be taken into account when designing its second variant. The goal of further research is to obtain significantly higher efficiency.
A theoretical basis has been developed for creating a software control system for two electromechanical actuators in order to ensure optimal control of the position of the SEC during every day of the year.