Performance Study Of Linear Liquid-immersed Solar Receiver In Medium CPV Systems

As the most promising energy in the research of renewable energy, solarphotovoltaic electricity has become the focus in the development and utilization ofnew energy. Concentration Photovoltaic system (CPV) as one of the effective ways toreduce the generation cost, has been paid more and more attention.The dissertation based on the immersing cooling technology, dimethyl silicon oilwas selected as cooling medium. Based on the A17-85concentration silicon solarcells, a cell module and a linear liquid-immersing receiver were fabricated. Combinedwith the flat mirror concentrator, a liquid immersion CPV (LICPV) experimentalsystem was build up. Influence rulers of DNI and flow rate of silicon oil on theperformance of cell module were investigated. For the characteristic of receiver, anupper channel and lower channel model was build up to analysis the temperaturedistribution of cell module, average temperature, the convective heat transfercoefficient between surface of cell module and cooling medium. Based on the5-parameter I-V model method, the correction term Rsswas added in the model andthe model parameters extracted from the test data were used to predict the electricalperformance of cell module.Experimental results show that:1) When the flow rate of silicon oil is30L/min,average DNI is820W/m2, ambient temperature is29oC, along the axial direction, themaximum temperature differences of the rear surface of cell module is4.2oC, and2.6oC for front surface. Along the radial direction, the temperature difference of cellmodule is less than2.9oC. The average temperature of cell module’s front surface is45.9oC, while the rear surface is42.0oC.2) The thermal resistance of the cell moduleis0.0159K/W, the adhesive layer contribute to98.2%of the total thermal resistanceand not conductive to transfer heat from front surface to rear surface.3) Comparedwith the convective heat transfer capacity of the upper channel and lower channel, theconvective heat transfer between the front surface of cell module and lower channeldominated the whole heat transfer process. The increasing of Re will improve the heattransfer performance of the liquid immersing method, and the temperature distributionof cell module will be more uniform.4) A17-85concentrator silicon solar cell wasselected to test the accuracy of5-parameter model method. Compared with the predicting results and the real test data, it can be concluded that the5-parametermodel method has highly accuracy when the concentration ratio is less than20X. Ahighly accurate predicting result can be obtained when the electrical parameters comefrom cell module rather than basic cell. The single cell+series-parallel model have atheoretical significance for design of LICPV system and module.5) Based on the cellmodule parameters model, DNI and inlet temperature Tinas the system variables andthe LICPV system model was build up to predict the thermal and electricalperformance of the LICPV system, the predict results of CH2cell module was fairlyclose to the real test result.