The hybrid (PVT) double-pass system with a mixed-mode solar dryer for drying banana

In this paper, the hybrid PVT double pass system with a mixed-mode solar dryer type under forced convection has been designed, fabricated and installed for drying crops. The dryer was tried by drying 300 grams of banana slices in the air temperature of dryer range from 43.2 to 60.2°C. The initial moisture rate of banana was about 78% and the most dropped in moisture content was from 78% to 33% after 8 hours of the drying process. The banana slices are distributed in two identical trays and it was noticed that the most and least decreasing in weight of banana samples was from 150 to 48 gram and from 150 to 55 gram in lower and upper tray respectively, when the mass flow rate as 0.031 and 0.017 kg/s, which means that the high reduction was 68% of weight banana at a high mass flow rate of airflow. The critical parameter such as temperature distribution of the PVT with dryer room, useful heat gain, and thermal efficiency are computed by using the MATLAB 2015b program built for this purpose. The optimum useful heat gain and thermal efficiency were reached 423.7 and 52.98% respectively when the solar radiation 1190 and the mass flow rate of 0.031 kg/s.

A Study on Developing an Automatic Controller with an Inverter Collector Pump for Solar-Assisted Heating System

In this study, based on the optimal equation m = 0.05 Δ T A c (kg/min) of the variable mass flow rate in the collector loop, an automatic controller with an inverter collector pump for the collector loop of the solar-assisted heating system is designed for these experiments and to then be used for real industry. The pump for the collector loop is an inverter type that is controlled by an embedded controller with Windows, based on C# language, and the change of speed depends on the variation of the mass flow rate through the collector loop. The input of the automatic controller with an inverter collector pump is given by a thermocouple input module that is connected to the embedded controller with the RS-485 communication protocol. In this work, the experiments were carried out on three different days, namely a clear day, an intermittently cloudy day and an overcast day, to evaluate the stability and the precision of the automatic controller, as well as the contribution of the useful heat gain from the collector for the solar-assisted heating system. Simulation and experimental results are also validated and analyzed.

A review of Thermal Performance of Solar Concentrator – the future needs

Abundant solar energy is freely available almost round the year in India. As per the current scenario of global warming and climatic change, solar energy is the cleanest source in nature. Concentrated solar power (CSP)has hardly contributed to the overall installed solar power capacity in the country. CSP technologies are Parabolic Trough Collector (PTC), Linear Fresnel Reflector (LFR), Paraboloid Dish and Solar Power Tower. This paper presents a review of CSP in solar parabolic dish concentrator to understand thermal aspect like thermal efficiency, optical efficiency, useful heat gain, heat losses, solar irradiation, etc. for various applications and current development. The current scenario of global CSP is discussed to meet the future challenges and need of the society.

Design and Implementation of an Automatic Control for Two Axis Tracking System for Applications of Concentrated Solar Thermal Power

The present work presents design and implementation of an automated two-axis solar tracking system using local materials with minimum cost, light weight and reliable structure. The tracking system consists of two parts, mechanical units (fixed and moving parts) and control units (four LDR sensors and Arduino UNO microcontroller to control two DC servomotors). The tracking system was fitted and assembled together with a parabolic trough solar concentrator (PTSC) system to move it according to information come from the sensors so as to keep the PTSC always perpendicular to sun rays. The experimental tests have been done on the PTSC system to investigate its thermal performance in two cases, with tracking system (case 1) and without tracking system (case 2). The experimental results showed that the average solar radiation falling on the PTSC prototype in the two cases during the same time was 854 and 701 watt/m2, respectively, which means an increase in the solar radiation about 21.8 % when using tracking system. It was found that the average useful heat gain output of solar collector was equal to (376.2, 252.6 watt) for the two cases, respectively, so there was an increase of about 48.9 % when using the tracking system. Also, the average thermal efficiency of the PTSC was found to be (20.7, 26.5 %) for the two cases, respectively, which means an increase in the average efficiency by 28% with use of tracking system compared to the fixed case.

Thermal Performance Analysis of Parabolic Trough Solar Concentrator with Helical Tube Receiver

In this paper, the experimental thermal performance for a parabolic trough solar concentrator (PTSC) combined with helical tube receiver and directed by two axes solar tracking system at different amount of water flow rates has been analyzed. The experimental test results of thermal performance with regard to temperature rise of water, useful heat gain and collector thermal efficiency for the PTSC prototype at controlled water flow rates (2.3, 22.5 and 29.4 L/h) are collected. The results show that the increase of water mass flow rates causes decrease in the average water output temperature as (120.8, 63.82 and 46.08oC), respectively, the maximum outlet temperature becomes (160.5, 76, 47) oC, respectively, and thus, the average useful heat gain will be (1249.4, 732, 732.5W), respectively and the average thermal efficiency decreases as (73.021, 49.51 and 44.31 %), respectively. The experimental results show that decrease the water mass flow rate by 74.4%, causes an increase in the thermal efficiency of the PTSC by 64.7%.

EXPERIMENTAL INVESTIGATION ON PARABOLIC TROUGH SOLAR COLLECTOR HOT WATER GENERATION SYSTEM

In this work, we investigated the performance of parabolic trough solar collector with hot water generation system for 3 days day time. We observed the differences in temperature in the range of 6.7°C to 24°C. The average beam radiation during the testing period is 658W/m2. The temperature difference, useful heat gain, wind velocity, direct beam radiation, absorber temperature and solar flux are found in the test period from 9.00 a.m to 16.00 p.m.

Design Calculation of Parabolic Trough Solar Thermal System and Three-phaseTurbo Alternator

Solar energy can be converted into thermal energy with the help of solar<br />collectors. Electricity can be produced directly from solar energy using<br />photovoltaic devices or indirectly from steam generators using solar thermal collectors to heat a working fluid. This research is using the conversion of solar energy into electricity in a closed cycle driven by natural convection. It would mean that electricity is cheaper than from any other renewable technology and cheaper than from fossil fuels. This paper describes converting thermal energy collected by solar collector to electricity by using turbine. Anywhere in Myanmar will cheaply use electricity by using solar turbine generator. Remote areas will improve more and more when getting the efficient electricity. The design calculation and performance predication of 1 MVA turbo-alternator/generator are also mentioned. Design calculation of absorbed flux, useful heat gain and exit temperature is described. And then development of two-tank thermal storage system that uses molten salt as the heat transfer fluid is described.

A Simulation Model for Predicting the Performance of Solar Domestic Hot Water System

The article deals with the modeling and simulation aspects of the performance improvement of a solar domestic hot water system. A mathematical model of this system is carried out to predict its operating performance under specified weather conditions of Jeju Island, Korea. The optimum mass flow rate through collector based on the relationship between the useful heat gain of solar collector and the electricity consumption of solar pump is investigated. Besides, the effect of various parameters such as solar collector area, initial water temperature and volume of storage tank is analyzed. The result of the simulation shows that the optimum mass flow rate was determined at kg/s with the new coefficient . At this value, the amount of useful heat gain slightly decreased about 84.3 (Wh) corresponds to 0.16% but the amount of electricity consumption strongly decreased about 227.8 (Wh) corresponds to 48.8% compares with kg/s ( ) was proposed by . Furthermore, the system performance is affected strongly by the change of collector area, initial water temperature and volume of storage tank.

Parabolic Trough Solar Collector – Design, Construction and Testing

This paper presents the design, construction and investigates an experimental study of a parabolic Trough Solar Collector (PTSC). It is constructed of multi – piece glass mirror to form the parabolic reflector (1.8 m ? 2.8 m) its form were checked with help of a laser and carbon steel rectangular as receiver. Sun tracker has been developed (using two – axis) to track solar PTSC according to the direction of beam propagation of solar radiation. Using synthetic oil as a heat transfer its capability to heat transfer and load high temperature (?400 oc). The storage tank is fabricated with stainless steel of size 50 L. The experimental tests have been carried out in Baghdad climatic conditions (33.3o N, 44.4o E) during selective days of the months October and November. The performance of PTSC is evaluated using outdoor experimental measurements including the useful heat gain, the thermal instantaneous efficiency and the energy gained by the storage tank oil. The storage tank oil temperature is increased from 30oc at 9:30h to 136oc at 13:30h without draw – off oil. The experimental result shows the average thermal efficiency was 42% which is fairly acceptable assessment results of a PTSC locally.