The Performance of Photovoltaic System for Pumping Water at Various Lifting Heads

These studies investigate experimentally the performance of photovoltaic system for operating the pump coupled by dc-motor. The photovoltaic panel with total area 1.9848 m2 consists of three modules of 80 WP each. The small centrifugal pump is operated to lift water 1m, 2m, 3m, 4m heads and gives the amount of water pumped over the whole day from 0800 to 1700 h are 8294, 7296, 5661, 3925 L/d respectively. The hourly global solar radiation during the day is an average of 506 W/m2. This study is also presented the I-V characteristics of the panel at global radiations 300, 500, 700, 900 W/m2 matched with the operation of the pump at the above lifting heads

The Comparison between the Effects of Using Two Plane Mirrors Concentrator and that without Mirror on the Flat- Plate Collector

The aim of the study is to compare between the effects of using two planes\ud mirror concentrator and that without mirror on the flat plate collector. The work is performed\ud on solar water heating system with flat plate collector installed in it. Measuring of the data are\ud taken between 9.00 to 16.00 h over a day. Based on the global and diffuse radiations with the\ud average of 594 and 119 W/m2, the average efficiencies of the system over a day are 41.90 %\ud and 22.80 % for collector with and without mirror respectivel

Investigation and Evaluation Steam Generator Performance of the Steam Power Plant, Tello Makassar with Energy and Exergy Analysis

This working paper were presented in the ICCHT2010 ??? 5th International Conference on Cooling and Heating Technologies, Bandung, IndonesiaThis study was conducted at the unit steam power plant, Regional VIII of The State Electricity Enterprice (PLN), located in Tello village, Panakukang subdistrict, city of Makassar, province of South Sulawesi. The analysis was carried out to calculate the energy and axergy in steam generator which are consisted of: furnace, economizer, evaporator, three superheaters, and two air heaters. The calculations are based on the all data recorded during the operation of steam power plant at the maximum electricity load of 10.3 MW. Based on exergy analysis, four components in steam generator ie: economizer, superheater IA, superheater II, and air heater I, give efficiency below 50%, and steam generator???s overall efficiency is only 25.01% but the overall effeciency calculated by enery method gives 58.04%

Low mass fraction impregnation with graphene oxide (GO) enhances thermo-physical properties of paraffin for heat storage applications

Whereas previous researchers analyzed the thermal behavior of paraffin waxes impregnated with graphene oxide nanoparticles (P-GONP) at high mass fraction ( > 1%), this paper analyzes behavior and stability at only 0.3% mass fraction. GONP was prepared by Hummer’s method. The morphology was studied using scanning electron microscope (SEM), transmission electron microscope (TEM), X-Ray diffraction (XRD) and Fourier Transformation-Infrared (FT-IR) Spectrometer and the thermal properties were measured using laser flash analyser (LFA), differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA) and thermal cycling. LFA showed a 101.2% and 94.5% increase in the thermal conductivity of P-GONP compared to pure paraffin (P) in solid and liquid state respectively. Melting and solidifying temperatures and latent heat were found to be 63.5, 59 °C & 102 kJ/kg and 57.5, 56 °C & 64.7 kJ/kg for P and P-GONP respectively. Thermal cycling over 4000 cycles showed that P-GONP was 27% more stable than P. The latent heat was 64.7 kJ/kg, a 36.5% deterioration compared to virgin paraffin. Compared against higher mass fraction impregnation, lower mass fraction P-GONP was found to have almost equivalent thermo-physical properties (namely thermal conductivity, melting and solidifying characteristics, thermo-chemical stability and reliability) while providing considerable cost saving