EXPERIMENTAL INVESTIGATION AND NEURAL NETWORK PREDICTION OF THE PERFORMANCE OF A MIXED MODE SOLAR DRYER FOR COCONUT

The shelf life of agricultural food products may be enhanced by reducing their moisture contents, by means of a drying process. The present work aims at drying coconut yielding copra. This paper presents the design, analysis of a mixed mode solar dryer for food preservation and energy saving. In the mixed mode solar dryer, the drying cabinet absorbs solar energy directly through the transparent roof and during the same time the heated air from a solar collector is passed through a tray. Various measurements like solar radiation, mass flow rate, and moisture content and relative humidity have been observed. From previous literature four different models (Newton, Page, Henderson & Pabis and Wang & Singh) are chosen for testing the performance of mixed mode solar dryer. Selected models are evaluated by using EMD, ERMS, R2 and ðœ’2 and it is concluded that page model is more suitable for the fabricated cabinet solar dryer at air flow rate 0.009Kg/s based on the experimental analysis. The direct radiant solar energy and a convective hot air stream dry the products, resulting in longer life for the products which are also free from impurities. The experimental results are utilized to evolve a suitable mathematical model, among the different models that are chosen, for copra. This will help in designing suitable dryers for actual users. Also, a multilayer neural network approach has been used to predict the performance of a mixed mode solar dryer for drying coconut. The simulation of neural network is based on the feed forward back propagation algorithm

Experimental study on double pass solar air heater with thermal energy storage

AbstractA double pass solar air heater was fabricated and integrated with thermal storage system. Paraffin wax is used as a thermal storage medium. The performance of this heater was studied for different configurations. The solar heater integrated with thermal storage delivered comparatively high temperature. The efficiency of the air heater integrated with thermal storage was also higher than the air heater without thermal storage system. The study concluded that the presence of the thermal storage medium at the absorber plate is the best configuration

Analysis of Cooling Applications for Solar Thermal-Energy-Storage System

This paper presents the experimental setup built to study a Thermal-Energy-Storage System (TESS) based on concrete as packed-bed using air heat-transfer fluid. Thermal energy storage using sensible heat storage materials have gained much interest in the renewable energy storage sector due to its relatively low cost, abundant availability and technical development. The objective of this work is to design, fabricate and test a sensible heat thermal-energy-storage system. This work can be actualized in low-temperature cooling. A use of this work on low-temperature cooling is by utilizing silica gel-water adsorption chiller which can be driven by 55◦C of heated water. In this examination, two tests have been completed warmth stockpiling components of various porosities and surface area. The parameters such as porosity and surface area influence heat-transfer by conduction and convection. Also, numerical analysis is being carried out to have a detailed analysis of the problem for varying parameters and to compare with experimental results

Performance evaluation of building-integrated photovoltaic systems for residential buildings in southern India

The integration of photovoltaic modules into the building structure is a challenging task with respect to power generation of PV module and the effect of incident solar radiation. The performance of building integrated photovoltaic (BIPV) modules varies depending upon the orientation and azimuth angle of the building. In this work, the year-round performance and economic feasibility analysis of grid-connected building-integrated photovoltaic (GBIPV) modules is reported for the hot and humid climatic regional condition at Kovilpatti (9°10′0′′N, 77°52′0′′E), Tamil Nadu, India. The appropriate mounting structures are provided, to experimentally simulate the performance of GBIPV modules at various orientations and inclination angles (0° to 90°). The result indicated that the optimum orientation for installation of BIPV modules in the façade and walls is found to be east while that for a pitched roof south orientation is recommended. The overall average annual performance ratio, capacity utilisation factor, array capture loss and system losses are found to be 0.83, 23%, 0.07 (h/day), and 0.17 (h/day), respectively. In addition, the economic feasibility of grid connected PV system for residential buildings in Tamil Nadu, India is analysed using HOMER by incorporating both a net metering process and electricity tariff. Practical application: Grid-connected building-integrated photovoltaic system has many benefits and barriers by being installed and integrated into the building structure. The application of GBIPV in building structures and its orientation of installation needs to be optimised before installing into buildings. This study will assist architects and wider community to design buildings facades and roofs with GBIPV system which are more aesthetic and account for noise protection and thermal insulation in the region of equatorial climate zones. By adding as shading devices, they can reduce the need for artificial lighting, and moderate heating or cooling load of the buildings

Investigation of a binary eutectic mixture of phase change material for building integrated photovoltaic (BIPV) system

The incorporation of phase change material (PCM) into the building integrated semi-transparent photovoltaic (BISTPV) system is a promising technology to regulate the enhanced surface temperature of the photovoltaic (PV) system. In this work, Sodium Sulfate Decahydrate (Na2SO4·10H2O) and Zinc Nitrate Hexahydrate (N2O6Zn·6H2O) were mixed to form the binary eutectic PCM by heating mixing method. The results of Differential Scanning Calorimeter (DSC) characterization of those eutectic mixtures showed that the molar mass proportion of 70% weight of Na2SO4·10H2O and 30% weight N2O6Zn·6H2O was an optimum eutectic mixture for the solar energy applications. The developed eutectic mixture was employed in the specially designed and fabricated building-integrated semi-transparent photovoltaic phase change material (BISTPV-PCM) system to regulate BISTPV cell temperature. The experimentation was carried out at the outdoor environmental conditions in the region of Kovilpatti (9°10′0″N, 77°52′0″E), Tamilnadu, India throughout the year of 2018. The instantaneous peak temperature was reduced up to 12 ᵒC for the BISTPV-PCM system compared to the non-PCM counterpart. The annual output power generated from the BISTPV module was 34,287 W h/year which increased to 37,024 W h/year by using PCM