Study On Heat Collection Performance Of Carbon-plastic Flat-plate Solar Collector

With the rapid development of the global economy and the continuous growth of the population,a large number of environmental problems have arisen due to the massive use of primary energy,so it is necessary to vigorously develop low-carbon clean energy,as a kind of never-failing clean energy,solar energy has gradually attracted people's attention.Compared with other renewable energy technologies,solar thermal utilization is cheaper and more mature.Research on the performance improvement and optimization of flat-plate collector has also attracted extensive attention.Most of the traditional plate collector adopts heavy metal materials such as aluminum and copper,and the pipeline is easy to corrode.In this thesis,a kind of carbon-plastic flat-plate solar collector is designed.This kind of carbon-plastic flat-plate solar collector adopts plastic aluminum composite endothermic plate and plastic pipe,which can improve the corrosion resistance of the plate collector.On the outside of the plastic pipe,the plastic pipe and aluminum alloy can be tightly combined by ultrasonic rising joint technology.Ensure the heat collection performance of the collector.In this thesis,the structure and working principle of flat-plate collector are introduced.Combined with the energy balance equation,the transfer of solar radiation energy in flat-plate collector is analyzed,its mathematical model is established,and the heat loss coefficient is analyzed and studied in detail combined with thermal resistance network diagram,which lays a theoretical foundation for the experimental study of carbon-plastic flat-plate solar collector.Then,based on the theory of flat-plate collector,the specific structure size of carbon-plastic flat-plate solar collector is analyzed and designed,and the test platform of carbon-plastic flat-plate solar collector is built.The outdoor steady-state test method is used to carry out the test.The data of inlet and outlet temperature and inlet mass flow rate of environmental parameter collector are recorded,and thenormalization curve of instantaneous efficiency of collector is obtained as(9)-(28)i?64.9709.0T.According to the designed carbon-plastic flat-plate solar collector,the numerical simulation was carried out.First,the physical model of the collector was established by ICEM CFD software,and then the parallel meshing was carried out by importing FLUENT software.At the inlet temperatures of 303 K,309K,315 K and 321 K,the outlet temperature and temperature distribution of the collector were calculated.Finally,the simulation results are compared with the experimental results.The normalization curve of the instantaneous efficiency of the collector obtained by numerical simulation is(9)-(28)i?45.9727.0T,and the error between the two is less than3%,which proves that the numerical simulation is correct and feasible.The structure of the carbon-plastic flat-plate solar collector is optimized by numerical simulation.It is concluded that with the increase of the thickness of the endothermic plate,the increase of the inner diameter of the exhaust tube and the decrease of the width of the endothermic plate,the collector efficiency will be improved.The direction of the optimal design of the collector structure is determined,which has certain reference value for the design improvement of the flat-plate collector.