Assessment of Existing Photovoltaic System with Cooling and Cleaning System: Case Study at Al-Khobar City

On unsteady 3D bio-convection flow of viscoelastic nanofluid with radiative heat transfer inside a solar collector plate

Nanoparticles are used in industrial and engineering by allowing for faster heat transfer rates in microchips, vehicle cooling, food processing, and nuclear reactors. This research aims to scrutinize the three-dimensional bioconvectional flow performances of viscoelastic nanofluids through a elongating sheet with motile microorganisms. Radiative impact and solutal boundary conditions are studied here. The impacts of thermophoresis, Brownian motion, and bioconvection are also considered. By using suitable similarity transformations, the PDEs are converted into ODEs. The numerical and graphical results are calculated with the help of shooting scheme built-in function Bvp4c in computational tool MATLAB. The graphical and numerical importance of physical engineering parameters like local skin friction, local Nusselt, local Sherwood, and local motile microorganism numbers are discussed here. The thermal profile is enhanced for the higher estimations of the Brownian motion and thermophoresis parameter. The heat profile is boosted up for the increasing variations of the thermal radiation and the thermophoresis parameter. The energy profile is improved by increasing the estimations of solutal Biot number while declining for mixed convection parameter and unsteadiness parameter. The microorganism profile decays for Peclet and bioconvection Lewis number while rising for buoyancy ratio parameter and bioconvection Rayleigh number.

Research on Local Heating Regeneration Method for Air-Conditioning Systems

Absorption air-conditioning systems have a great advantage in terms of energy conservation and environmental protection. However, the large amount of energy waste in the thermal regeneration process leads to lower efficiency and impedes its development. To reduce energy loss and improve performance, a local heating regeneration method is proposed in this paper. The main principle is reducing the volume of the liquid participating regeneration. Including the solar steam mode, two modes are introduced and configured. Theoretical and experimental research has been made on the new methods. Models have been developed for comparison analysis. Experiments have been conducted on water and absorbent solution with different modes. Performance has been evaluated based on the experimental data. The results expose the influence of different parameters, like liquid volume and solution concentration, on the regeneration process. The local heating method improved the regeneration efficiency by 40% in the no solar steam mode and the performance tripled in the solar steam mode. The COP (the ratio of cooling load to energy consumption) of the absorption system with the solar steam mode is more than two times of that with the traditional regeneration mode. It shows the local heating regeneration method has good potential in future application.

Validation of SAM Modeling of Concentrated Solar Power Plants

The paper proposes the validation of the latest System Advisor Model (SAM) vs. the experimental data for concentrated solar power energy facilities. Both parabolic trough, and solar tower, are considered, with and without thermal energy storage. The 250 MW parabolic trough facilities of Genesis, Mojave, and Solana, and the 110 MW solar tower facility of Crescent Dunes, all in the United States South-West, are modeled. The computed monthly average capacity factors for the average weather year are compared with the experimental data measured since the start of the operation of the facilities. While much higher sampling frequencies are needed for proper validation, as monthly averaging dramatically filters out differences between experiments and simulations, computational results are relatively close to measured values for the parabolic trough, and very far from for solar tower systems. The thermal energy storage is also introducing additional inaccuracies. It is concluded that the code needs further development, especially for the solar field and receiver of the solar tower modules, and the thermal energy storage. Validation of models and sub-models vs. high-frequency data collected on existing facilities, for both energy production, power plant parameters, and weather conditions, is a necessary step before using the code for designing novel facilities.