Research On The Water-Cooled Solar Photovoltaic Module’s Heat Transfer Characteristics And Methods

Crystal silicon solar cell’s photoelectric conversion efficiency falls when its temperature rises, the output power may decrease by0.4～0.66%per Centigrade, so taking measures to cool down the solar cells’temperature is meaningful when they are working during the daytime.The paper researched on the heat-transfer characteristics and methods of solar photovoltaic module’s water cooling. It uses water as the solar cells’coolant, and presents two methods to realize:one is to store water, which inherits the former topic"Cool-storage solar photovoltaic module", the other is to use tap water, named "Tap water cooling solar photovoltaic module". Both of them have the same solar cells’model, the main difference of them is the heat exchanging way:the former uses a cool storage tank as the cooling equipment to realize the cooling for the solar cells while the latter uses pipes which contain tap water and wings’heat transferring to do so.Chapter2researched the solar photovoltaic module’s cooling load. First the paper programmed a simple calculation software by Visual Basic, transformed the observed climate data to the module’s received radiation data, next made a model of the module’s layers, listed energy equations for it, then presents methods such as using Maple12to solve them.Chapter3researched on the cool-storage solar photovoltaic module. In the water tank, one of the most complex hear transfer process is the process between module’s backplane and water. The author presents the "feedback and modify" method by using the simulation software FLUENT in order to aquire the cool-storage tank’s water’s natural convection heat transfer coefficient h, and got the h’s changing by time value tables under Standard Test Condition and actual climate conditions. What’s more, the paper compared the simulated data with experiment data in order to validate the accuracy.Chapter4researched on the method of cooling by tap water. In order to acquire the best heat transfer,lowest temperature and least resistancy section shape, the paper presents the refining method, made15different3D mesh models, and simulated by using FLUENT by one heat flux and3flow rates, get each model’s flat face’s average, maximum, minimum temperature and velocity tables, and select the best model which has the145.4×10-6m2section area. Basing on the above, the paper planned experiments, analyzed the precept of tap water cooling solar photovoltaic module combined with buildings, and calculated lOkW photovoltaiv roof top power plant’s cooling effects in different water flow rates.In order to find the best heat character and anti-corrosion material used for water cooling solar cells,4aluminium alloys were used for accelerate corruption, accelerate corruption, thermal diffusion coefficient, reflectivity and absorptivity tests, finally the best was chosen, and the aluminium alloys’changing principle under long-time using was held.Finally, the paper analyzed different cooling resourses and completed the related experiments, collected different places’water temperature in tap water, surface water and criculation water in Guangzhou university mega centre, then compared and analyzed their feasibility, advantages and disadvantages.During the theoretical and experimental researches, the conclusion shows the water storage method’s efficiency closely due to the convection heat transfer coefficient, which may be between7.25and78.11, and the tap water method due to the tap water’s temperature, the flow rate in its building, and the pipes’section shape. Results show the lOkW photovoltaiv roof top power plant’s power may rise from8.39kW to9.91kW. In future, this subject should do prototype tests to test and verify the paper.