Παραμετρική πειραματική μελέτη απόδοσης ηλιακών θερμοσίφωνων παραγωγής ζεστού νερού

Abstract

The object of this thesis is to investigate the energy performance of thermosyphon solar water heating systems using experimental methods.The experimental tests have been conducted at the Applied Center of Energy which is under the Ministry of Commerce Industry and Tourism.The energy problem is presented in parallel with the use of renewable energies with emphasis on the use and application of solar energy.The current situation of the solar collectors at the global and regional level is presented.Although several types of collectors are developed,the flat plate solar collector dominates the market.The history and use of flat plate solar collector in Cyprus is described with particular emphasis on the thermal efficiency.Various solar water heating systems are presented with emphasis to the thermosyphon system and its components, which are the flat plate collector, storage tank and auxiliary energy source.The factors affecting the performance of thermosyphon solar water heating systems are described.A number of tests have conducted to investigate the performance of solar water heating systems and find out how the above parameters affect the performance.The experimental tests demonstrated that the efficiency of solar water heating systems is affected by the weather conditions,the thermal insulation of the storage tank,the height difference between the upper part of the collector and the bottom of the storage tank and the correlation that exists between the collector and the storage tank.Specifically for the height between the upper part of the collector and the bottom of the storage tank a separate experiment was made to investigate whether and how the thermal performance of a thermal solar water heating is affected by the difference in system between the top of the collector and the bottom of the storage tank.