No abstract

No abstract

No abstract

No abstract

A preliminary experimental model of solar vortex power generation (SVPG) has been built for the evaluation of the newly introduced system. It experienced set back in the design of the inflow guiding arrangement. This paper presents a numerical simulation of swirl air generator as part of the proposed SVPG. ANSYS FLUENT software has been used to solve Navier-Stokes and energy equations in cylindrical coordinates system integrated with discrete ordinates radiation model. The configuration of the swirl air generator was modelled and simulated with eight air inflow. Each air inflow comprised of the open slot for air flow and guide vane. Two different heights, 0.3 m and 0.6 m of the air entry have been simulated. The Computational fluid dynamics (CFD) simulation procedure has been validated with the help of results that were acquired through the measurements carried out utilizing the experimental model constructed in the solar research site (SRS) at the Universiti Teknologi PETRONAS, Malaysia. The computational results show that by increasing the height of guide vanes and the inflow slots the swirling strength enhanced by 50%. The mass flow rate under the same operational solar and weather conditions was improved by 50%. Thereby, a decision has been made to modify the existing system based on the present CFD simulation results.

No abstract

The generation of electricity from solar energy is becoming a very exciting subject for numerous countries. However, despite the advantages of this type of energy source, the limited use of this source after sunset and at night is still a major challenge. In this study, a solar chimney model was selected as a system for generating electrical power. These types of plants remain interesting, especially in open areas far from cities. In this research, a numerical model has been proposed as a day and night functional solar system using waste heat or any external heat source to enhance the system performance and make it generate power for 24 hours. With the help of ANSYS Fluent software, the discrete ordinates radiation model was used to solve three-dimensional steady-state Navier-Stokes and energy equations in the cylindrical coordinate system. For the preliminary model, the results were validated using experimental measurements. Then the simulation was carried out on the proposed model with an external heat source by using thermal enhancing channels. Afterwards, the influence of the external heat source on the system performance was predicted and analysed. The simulation results showed that this system could enhance the plant during the day time and ensure its operation at night. The simulation showed a positive effect of the external heat source on solar chimney power plant efficiency by using the proposed model. Percentage enhancement was 6.5% and 13% for velocity and temperature respectively, in comparison with the preliminary model. Moreover, in this study, the power enhancement for the proposed system reached 37%.

In this study, a novel approach has been proposed as a solar chimney integrated with an external heat source to extend the system operation during the absence of solar energy. Flue gas channels have been utilized to exchange heat with the air inside the collector of the solar chimney. The hybrid solar chimney has been investigated numerically by ANSYS-Fluent software, using discrete ordinates radiation model. The hybrid system was simulated in 3D, steady-state by solving Navier-Stokes and energy equations. The numerical results have been validated using experimental measurements of a conventional solar chimney. The influence of flue channels on the system performance was predicted and analyzed in hybrid mode. With 0.002 kg/s of flue gas at 100°C injected in flue channels during the daytime; hybrid mode results demonstrated enhancement of 24% and 9 % for velocity and temperature, respectively. The power generation was enhanced by 56%. It has been proved that the proposed technique is able to resolve the set back of night operation problem of the solar chimney plants.