H.A. Hussein; A.H. Numan; A.R. Abdulmunem
Abstract
This work presents an improving of the photovoltaic / thermal efficiency by using a solar tracking system (2-axes) and AL2O3 mixed with water as working fluid. An integrated system ...
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This work presents an improving of the photovoltaic / thermal efficiency by using a solar tracking system (2-axes) and AL2O3 mixed with water as working fluid. An integrated system (PV/T) consists of 36 mono-crystalline solar cell was designed and implemented with cooling water technique utilized copper pipes on the back PV side to flow cooling water at different mass flow rates . A (90) bulbs of (12V, 50W) are connected in series are used to simulate the sun light and controled by (3) AC to AC transformers to give different irradiation arrive up to (1000 W/m2).The (AL2O3) was prepared and added to the water with different concentrations to decrease the temperature of PV and increase the rate of heat transfer to maintain good electrical efficiency and an increase in thermal efficiency.The experimental work has been conducted in (UMPEDAC) / Malaysia. The experimental results indicated that when using two- axes solar tracking system the output power generated was increased from (21.69W) to (30.69W). The power module generated is decreased when the temperature of PV surface increased from (64.05W at 24.7oC) to (39.46W at 79.1oC). It is proved that the temperature of PV surface is rising and that efficiency does not exceed 8%, if there is no water-cooling while under the influence of process cooling water, the efficiency increased to 9.6%. In addition, it founded that the optimum mass flow rat of water was (0.2) L/s. At using nanofluid (AL2O3-water) as a percentage ratios (0.1, 0.2, 0.3, 0.4, 0.5) % at constant mass flow rate (0.2) L/s, the temperature dropped significantly from (79.1oC) to (42.2oC). It is found that an optimum concentration ratio of nanofluid at 0.3% and the electrical efficiency of PV/T was 12.1% while the thermal efficiency was 34.4%.
