Effect of the Tilt Angle of Natural Convection in A Solar Collector with Internal Longitudinal Fins,”

Abstract-We present in this paper, a series of experimental tests carried out on a solar plan, with an area of 1.8236 m 2 capture, designed in the laboratory and tested in the region of Biskra. The complete experimental setup includes the measurement of global solar radiation, wind speed, airflow velocity and temperature and the ambient air at the inlet and outlet; optimize a tilt angle. The solar collector was oriented facing south Renewable and domestic energy source, and is essential components of a sustainable energy future. This paper deals with the influence of the tilt angle of solar collectors. The optimum angle is measured by searching for the values for which the total radiation on the collector surface is a maximum for a particular day or a specific period. An application of the model is done using the experimental data measured for Biskra in Algeria. For increasing the utilization efficiency of solar collectors, it is recommended that, if it is possible, the solar collector should be mounted at the monthly average tilt angle, and the slope adjusted once a month

Collector Efficiency by Single Pass of Solar Air Heaters with and without Using Fins

This paper presents the study of heat transfer in a solar air heater by using new design of solar collector. The collector efficiency in a single pass of solar air heater without, and with using fins attached under the absorbing plate has been investigated experimentally. Due to the adding the fins inferior an absorber plate, the desirable effect of increasing the heat transfer coefficient compensates for the undesirable effect of decreasing the driving force (temperature difference) of heat transfer, while the attached fins provide an enlarged heat transfer area. In this study, the absorbing plate of solar collector is attached with fins for further improved performance. The improvements of collector efficiencies in the single pass solar air heaters with, and without fins attached; increase with increasing the mass flow rate, especially for operating at lower air flow rate. Experiments were performed for two air mass flow rates of 0.012 and 0.016 kg/s. Moreover; the maximum efficiency obtained for the 0.012 and 0.016 kg/s with, and without fins were 40.02, 51.50% and 34.92, 43.94% respectively. A comparison of the results of the mass flow rates by solar collector with, and without fins shows a substantial enhancement in the thermal efficiency

Parametric Study of to Design an Earth to Air Heat Exchanger with Experimental Validation

Geothermal energy uses an air ground exchanger to cool buildings with minimum of energy. The outlet air coming from this exchanger can be directly used for space cooling if its temperature is low enough. In this study we try to evaluate the profile of ground temperature to decide of the depth to bury the exchanger. Through modeling and experimentation, we try to evaluate the performance of a horizontal pipe used for cooling, for this finite differential method which consists on dividing the length of the exchanger on multiple equal segments and by the knowledge of initial and boundary conditions the profile of the air temperature is that carry out. The authors conclude that many parameters influence the performance of earth to air exchanger such as the nature of the ground, the ground depth diameter of the duct and the throughput flow

Structural Damage Detection by Using Finite Element Method as Function of Length

The work described in this paper involves the effect of length and fibre orientation of the composite damping for comparison with the analytical results. The calculation of laminate damping is performed by use of a strain energy method. The modal analysis of the structure for different loading rates is based on the analytical method used to solve the equation of free vibrations. The difference between strain energies for both cases (damaged and undamaged) are calculated by the finite element method. The structural damping of the different beams is evaluated from these energies. The decrease in frequency for different rates of loading shows the loss of stiffness for all lengths studied

Heat transfer and energy analysis of a solar air collector with smooth plate

The heat transfer and thermal performance of a single pass solar air heater a smooth plate was investigated experimentally. In the present paper, energy and heat transfer analysis of a solar air collector with smooth plate, this technique is used to determine the optimal thermal performance of flat plate solar air heater by considering the different system and operating parameters to obtain maximum thermal performance. Thermal performance is obtained for different mass flow rate varying in the array 0.0108–0.0202 kg/s with five values, solar intensity; tilt angle and ambient temperature. We discuss the thermal behavior of this type of collector with new design and with my proper construction. An experimental study was carried out on a prototype installed on the experimental tests platform within the University of Biskra in the Algeria. The effects of air mass flow rate, emissivity of channel plates and wind heat transfer coefficient on the accuracy of the criterion are also investigated

Experimental study of heat transfer and thermal performance with longitudinal fins of solar air heater

The thermal performance of a single pass solar air heater with five fins attached was investigated experimentally. Longitudinal fins were used inferior the absorber plate to increase the heat exchange and render the flow fluid in the channel uniform. The effect of mass flow rate of air on the outlet temperature, the heat transfer in the thickness of the solar collector, and the thermal efficiency were studied. Experiments were performed for two air mass flow rates of 0.012 and 0.016 kg s−1. Moreover, the maximum efficiency values obtained for the 0.012 and 0.016 kg s−1 with and without fins were 40.02%, 51.50% and 34.92%, 43.94%, respectively. A comparison of the results of the mass flow rates by solar collector with and without fins shows a substantial enhancement in the thermal efficiency

The Deposition Temperature Dependence on the Crystallite Size of NiO Thin Films

In this article, we have investigated a fitting proposal model for calculating the crystallite size of pure NiO thin films by varying the structural parameters, such as full width at half-maximum β, lattice parameter a and differences in a − a0. The experimental data of NiO thin films were prepared at several deposition temperatures in the range of 380–460°C. All estimated values of crystallite sizes are proportional to the experimental data. Thus, the measurement of the crystallite size values by this proposed model is compatible with practical measurements qualitative

Experimental Study of Heat Transfer and an Effect the Tilt Angle with Variation of the Mass Flow Rates on the Solar Air Heater

Abstract-in this study we have been indicated an effect of tilt angle and the mass flow rates onto the thermal performance of a single pass solar air heater will be investigated experimentally. The effects of mass flow rate of air on the outlet temperature, the heat transfer in a solar collector and thermal efficiency were studied. Experiments were performed for range of air mass flow rates from 0.0078 to 0.0166 kg/s., Moreover; the maximum efficiency was obtained at the difference's mass flow rates. The maximum efficiency obtained for the 0.0078, 0.0093, 0.0125 and 0.0166 kg/s were 47.82%, 37.50%, 31% and 26% respectively. Comparison of the results as an effect the mass flow rates by solar collectors and the tilt angle a substantial enhancement in the thermal efficiency. The optimal tilt angles for the outlet temperature were between 20 and 30°