الفهرس | Only 14 pages are availabe for public view |
Abstract Solar energy is now a feasible and affordable alternative to the non-renewable and environmentally polluting fossil fuels. The conversion of solar radiation into heat, which can be used for heating systems, is one of the easiest and most direct uses of this energy. Since the market is flooded with various types of solar energy systems, such as solar collectors, and because these types are made in different countries and work differently depending on where they are installed, it was necessary to assess their effectiveness in order to provide home owners and solar technology suppliers with information that will help them get the most out of their investments. This study presents monitoring of the performance of different commercial types of solar thermal collectors under our environmental conditions at Fayoum University. The study has been monitored both experimentally and theoretically by a Swiss simulation software package ‘POLYSUN’. Three different types of commercial solar thermal collectors were tested (glazed FPC with selective absorber (SOLE Wasco 200), glazed FPC with non-selective absorber (SOLE NS 2.00) and U-pipe ETC (SOLE V15)). The tests were performed at the same time with same conditions: latitude, tilt angle, direct of installation, global radiation, inlet temperature, ambient temperature. The monitoring of the performance for the three collectors were also done by using POLYSUN V 9.1 to show the effectiveness and accuracy of POLYSUN which can be used to accurately determine a system's output under actual operating conditions. Based on the results of the simulations, optimizations for the best operating conditions for these collectors in practical application were chosen. The practical experiments were run at the same time for the three collectors to ensure the same environmental conditions. Then comparison between the practical work and the simulation was made. The results show that the optimum flow rate for the 11 tested collectors was 30 l/h. The predicted performance done by POLYSUN showed excellent agreement with the experimental results for all the tested collectors. Also, POLYSUN was utilized to predict the performance over 12 months and declared considerable sessions’ impacts on the efficiency of the collectors. ETC showed more stable performance than FPC over the tested period. These results are a testament that POLYSUN is a reliable software tool, which can be used to effectively and accurately design the solar thermal systems. |