Determination of Useful Energy in Solar Evacuated Tube Collectors in Different Months of Year in Delhi

In this paper to fulfil the requirement of low intensity thermal energy solar evacuated tube setup is designed. The number of parallel tubes in the setup is determined on the basis of mass flow rate required and pressure drop. To get higher target temperature the number of setup can be connected in series. In our study evacuated tube set up consists of ten tubes. The inner tube is made of copper coated with black and outer tube is made of borosilicate glass. The space between inner and outer tube is evacuated. The solar radiation falling on the setup is determined at tilt angles β = φ-15°, β = φ, β = φ+15°. It is found that maximum solar radiation is 5.31 MJ/m² at β=φ+15°, while in same month it is 2.98 MJ/m² at β = φ-15° and 3.59 MJ/m² at β=φ. The maximum useful energy accounting thermal losses can be also computed in different seasons of year. It is found 4.35 kJ/s during summer season (February- March), 3.29 kJ/s during rainy season (June-September) and 3.69 kJ/s during winter season (October-January).