Critical interpretation and analysis to correlate the canopy height to collector diameter ratio for optimized design of solar chimney power plants

المجلة: International Journal of Renewable Energy Development

سنة النشر: 2023

تاريخ النشر: 2023-12-07

The collector's periphery height determines the entrance size to the solar chimney power plant. There is inconsistency in the published experimental and numerical results on the optimum collector inlet height for different collector diameters. This paper aims to analyze the available data to identify the best collector inlet height-to-diameter ratio and to introduce a design guide for an optimized performance of solar chimney power plants. The experimental data reported in previous works have been clustered and manipulated to produce a comparative argument on the collector inlet height-to-diameter. In addition, a numerical model is developed to support the literature conclusions and to produce further data to decide the optimum collector inlet height-to-diameter ratio. For a 6.6-m collector diameter, four different inlets have been investigated, namely, 0.05, 0.1, 0.15, and 0.2 m. The best performance in terms of air velocity and temperature rise is obtained with the 0.05-m inlet height, where it shows an improvement of up to 35.35% compared to the larger inlet heights. The lower collector inlet height allows a more effective heat transfer from the ground and the collector to the air. It is concluded that the optimum collector inlet height-to-diameter design ratio for solar chimneys with collector diameters larger than 3 m is 0.0075±0.0005. For small-scale solar chimney models with less than 3 m collector diameter, the best collector inlet height-to-diameter ratio ranges between 0.015 and 0.03.

Enhancement Thermal Conductivity of PCM in Thermal Energy storage

المجلة: 2nd International Scientific Conference of Al-Ayen University (ISCAU-2020)

سنة النشر: 2020

تاريخ النشر: 2020-06-02

An experimental investigation of different thermal energy storage materials in the solar collector is studied in this paper. Both, sensible energy storage materials and latent heat storage materials (PCMs) are used to enhance the storage system of thermal energy. The size of the tested solar collector 2 m*0.8m*0.15 collector length, width, height. Experimental results obtained from the proposed model indicate that the solar collector model, having a composite of paraffin wax with 5% aluminum powder can continuous operation, and the maximum air temperature difference (ΔT) between air enter to collector and exit from the collector if the ambient of 24.7 ºC, the effect on the efficiency of the collector

Experimental Study on the Effect of Using Metallic Brushes on the Charging and Discharging Time of Thermal Energy Storage Unit

المجلة: Journal of Engineering

سنة النشر: 2015

تاريخ النشر: 2015-09-21

Phase change materials are known to be good in use in latent heat thermal energy storage (LHTES) systems, but one of their drawbacks is the slow melting and solidification processes. So that, in this work, enhancing heat transfer of phase change material is studied experimentally for in charging and discharging processes by the addition of high thermal conductive material such as copper in the form of brushes, which were added in both PCM and air sides. The additions of brushes have been carried out with different void fractions (97%, 94% and 90%) and the effect of four different air velocities was tested. The results indicate that the minimum brush void fraction gave the maximum heat transfer in PCM and reduced the time for melting for (ϵ=90%) up to 4.49 times as compare with the case of no brush. It can be seen that the addition of brushes in air side helped to reduce the solidification time and increase the convection heat transfer coefficient as the brush void fraction decreased. Also the minimum velocity (v = 1 m/s) gave maximum outlet temperature