Glass Collector Research Articles

Towards maximum cost-effectiveness: multi-objective design optimisation of insulating glass flat-plate collectors

A significant challenge in the advancement of solar thermal heating systems lies in the unexplored techno-economic potential of insulating glass flat-plate collectors. These collectors are constructed in accordance with the specifications of standard insulating glass units and have emerged over the past decade as a promising design concept for enhancing the cost-effectiveness of solar thermal systems. However, substantial findings regarding the techno-economic viability of their production are still pending. The aim of this paper is to optimise insulating glass collector designs for solar district heating applications by identifying key design parameters that maximise cost-effectiveness. This study employed a five-stage methodology. It included thermo-hydraulic collector modelling using MATLAB/Simscape and the CARNOT Toolbox. The model was validated against experimental performance tests. A Latin hypercube computational design with 250,000 samples was set up to train supervised machine learning metamodels and perform a multi-objective optimisation using an elitist genetic algorithm. The study identified the argon concentration, collector length, and width as critical parameters influencing efficiency. Larger, thinner collectors demonstrated superior performance due to reduced convective losses and increased aperture-to-surface ratios. The optimisation revealed that the insulating glass collectors could achieve a 7.7 percentage point increase in efficiency, a 19.4 % reduction in material cost, and a 14.5 % decrease in weight compared to market-available flat-plate collectors. However, the direct economic comparison was not considered strong in evidence due to a lack of economic data from technology providers. The most cost-effective designs featured an argon concentration of 99 %, sealing thickness of 31.2 mm, and a glazing thickness of 4.1 mm, and 4.5 mm, while collector length and width varied more significantly. The research findings indicate the techno-economic potential of insulating glass collectors, demonstrating their ability to outperform conventional flat-plate collectors in terms of cost-effectiveness and efficiency. Future studies should focus on producing and testing larger modules and incorporating production costs to fully realise their potential for solar district heating applications. This study provides valuable guidelines for IGU designers and producers aiming to develop cost-effective and efficient solar thermal collectors for district heating systems.

Design and performance evaluation of Front glass-covered photovoltaics-thermal hybrid system for enhanced electrical output and hot water production

Proof of concept is established for the thermal management of PV modules for the simultaneous benefit of electrical and thermal efficiency. It was achieved by designing the controlled open-loop water-based hybrid PV-T system and demonstrated for thermal management of 150W photovoltaic panel at natural solar conditions. In this integrated front glass-covered PV-T hybrid (IFG-PV-T) system, the PV panel is clipped between the front glass and rear aluminium collector without causing any permanent changes in the existing panel. The flow of water from the source tank is controlled by automated solenoid valve assembly coupled with thermocouples. The solenoid operational temperature is fixed at 40°C to controlled the PV surface temperature at an optimum range to mitigate the adverse effect on voltage and current output. The water layer thickness in the front glass box is optimized to filter the maximum infrared radiations and the collector's toughened glass feature allows the maximum light transmittance with super safety. The performance of the IFG-PV-T system has been evaluated in terms of variation in open circuit voltage, short circuit current, maximum power output, electric and thermal efficiency under the natural solar insolation for a week. Experimental investigations revealed that the open-circuit voltage is increased by ∼16.1 % with IFG-PV-T as compared to conventional PV panel. The increment can be attributed to the synergy of the front glass collector and solenoid valve operation at 40oC that regulates PV surface temperature and boost the current output. These factors have ameliorated the electrical efficiency of IFG-PV-T compared to conventional PV panel. The average thermal efficiency was 39.4 ​% wherein the IFG-PV-T system provides ∼100 ​L of hot water (38–41 ​°C) per day. The present controlled loop operation system and collector configuration have proven their significance for electrical power increment and concomitantly able to deliver moderate hot water which can be useful for any household or commercial application.

DEVELOPMENT OF SOLAR HEAT CONCENTRATION BOX DRYER AND LM 35 SENSOR AS TEMPERATURE MEASURING DEVICE

The solar heat concentration box is a system which convert the solar energy to heat energy in a closed system for farmers to dry their farm produce. The system uses solar collector to harness energy from the Sun and concentrate it on a drying chamber to remove moisture from plantain, tomatoes, yam and pepper harvested from the farm. The system have three compartments system. Firstly, heat chamber. The heat chamber is made up of a solar glass collector, reflector foil and a rectangular wooden box. This chamber converts the Sun energy to heat energy. It is mounted at angle of 60o to the drying chamber. Secondly, the drying chamber. The drying chamber comprises of a cuboids, tray and isolating material. This is the chamber where the farm produce is laid and removal of moisture takes place. Thirdly, an electronic system which is made up of LM 35 sensor is used to convert the heat distribution inside the drying chamber to temperature. The LM 35 is interface with an Ardiuno UNO microcontroller. The microcontroller converts the analog signal output generated from the sensor to a digital output signal which is been display on visual system. The electronic device will enable farmers measure the temperature of the drying chamber at a particular time or period of the day. The system will enable farmers to dry perishable farm produce which is seasonal. This will reduce food shortage and increase in the cost of such seasonal and perishable farm produce during harvest and off-season.

Control of mat thickness in electrospinning with transparent conductive glass collector

AbstractElectrospinning is a versatile technique for producing micro‐ and nanofibrous mats with great potential in many fields. However, reproducibility remains a key issue for product development. In particular, thickness is an important parameter for controlling electrospun fiber mats. In this study, we developed a method to control the polymer mat thickness during electrospinning. The mat thickness was controlled on the basis of the light transmittance and by using conductive indium tin oxide (ITO) glass connected to ground as a collector. Living cells were seeded on the fiber mat without detaching from the ITO glass, which enabled observation under a microscope and the evaluation of cell behavior. This study indicates that the thickness of the fiber mat can be consistently controlled by monitoring the light transmittance instead of the electrospinning duration and the mat can be easily observed under a microscope. This is expected to be particularly useful in the field of tissue engineering.

Design and fabrication of a double- chamber solar dryer

Object of research: This paper discusses the design and construction of a modified, cost effective solar dryer for use by the average Nigerian farmer or agri-business entrepreneur.
 Investigated problem: Local farmers often have a lot of difficulties in properly drying harvested agricultural produce for storage and processing purposes, safely and efficiently due to capital constraints. There was therefore a need for an efficient, low cost solar dryer design to aid in this pursuit.
 Methodology: The designed dryer is a passive dryer that makes use of heat energy tapped through glass collectors placed over the drying and air inlet chambers respectively. The dryer was designed and constructed with carefully selected, inexpensive materials with dimensions of 40cm x 40cm x 60cm for the drying chamber and dimensions of 10cm x 80cm x 40cm for the heating chamber. The glass collectors (4mm thick) were inclined at an angle of incidence of 17.26°. Okra slices were used to test the performance of the dryer.
 Results / Area of practical use: The study yielded a low cost (€145.60) modified solar dryer capable of drying agricultural produce in a safe and clean way. During eight (8) hours of drying under a temperature range of 39 °C – 45 °C, the initial weight of the okra slices reduced from 150g to 9g, 9g, 10g and 9g on each of the four trays of the drying chamber respectively. Local farmers and agripreneurs will be encouraged to make use of this clean alternative of drying food produce without the drawbacks from regular sun drying.
 Conclusion: There is need for more work to be done in terms of installation of solar panels to enhance dryer performance. More work should also be carried out on tests during the dry season for increased dryer efficiency.

Performance evaluation of modified forced convection solar dryer with energy storage unit for drying of elephant apple (Dillenia indica)

AbstractThe development and performance of a modified force convection solar dryer (MFCSD) for drying elephant apple slices have been presented in this research. The MFCSD consists of two solar collectors and a drying chamber of 20 kg drying capacity. The secondary collector is integrated with thermal energy storage unit using a phase change material—paraffin wax. Performance analysis of the MFCSD was studied for drying elephant apple (Dillenia indica) slices. The proposed design enhanced the collector thermal efficiency by 12% as compared to a conventional glass collector. Drying of elephant apple slices in MFCSD will limit exergy losses and increase exergy efficiency. The estimated uncertainty of the collector chamber and the drying unit of the proposed MFCSD were obtained as ±3.3% and ±1.0%. Quality analysis (proximity analysis and textural properties) of the fresh as well as samples dried in open sun drying, tray drying, and MFCSD was carried out. The contents of carbohydrates (47.85 ± 2.66) and protein (21.24 ± 1.68) were high in samples dried in MFCSD when compared to samples dried in other two methods. The ash content of the sample dried in MFCSD was found to be 10.25 ± 0.15%, which was higher than samples dried in tray dryer. The payback period for drying elephant apple in MFCSD is 2.56 years, which is lower than the lifetime period (20 years) of the dryer.Practical ApplicationsA traditional method practiced by small farmers for drying high‐value perishable fruits is conventional open sun drying (OSD). Owing to slow drying rate and excessive heating, products dried under the open sun lose their nutritious and medicinal qualities. The present work details the construction of a low‐cost solar dryer for the drying of elephant apple. The aim of the drying kinetics to develop the architecture aspects of the solar dryer is to refine the drying systems. The results showed that the performance of modified force convection solar dryer (MFCSD) assisted with thermal storage could improve the quality of dried elephant apple slices and reduce drying time in comparison with an OSD method and a tray drying method. MFCSD would be a suitable alternative to the conventional dryers employed commonly in the industries for the drying of high‐valued agricultural products, and it can also be restructured to any size according the requirements.

Performance enhancement of solar photovoltaic (PV) module using a novel flat plate (NFP) glass cover by reducing the effect of bird dropping (BD) settlement.

A massive bird dropping (BD) deposition on the common rectangular flat plate (RFP) of photovoltaic (PV) module is a matter of great concern in Western Rajasthan (WR) that diminish the overall energy production capacity of the system remarkably. In this research article, a prototype novel flat plate (NFP) design of a front glass cover of PV module is proposed to prevent the impact of BD settlement by the restriction of bird's sitting/movement on the front glass cover. In this regard, the performance analysis of PV module with common RFP and newly designed NFP glass covers has been assessed at the different inclination β° (0-90). The BD accumulation onto the both glass covers was explored by the optical transmittance profiles at the different tilt angles, i.e., explained by bird movement on each flat glass surfaces. Consequently, a significant amount of output electric energy has been gained in NFP design rather than RFP corresponding to particular tilt regions TR I (0° ≤ β ≤ 25°), TR II (25° ≤ β ≤ 60°), and TR III (60° ≤ β ≤ 90°). According to the results achieved, an excellent level of improvement in average power loss, ~ 97.85%, corresponding to optimal TR (III) has been detected by employing NFP glass collector.

Innovative On-Site Adapted System for Fish Migration with Flow Divider and Glass Collector Basin

Abstract The authors designed a new site-adapted fish passage system for upstream and downstream migration of small and large fish on the urban sector of the Bistriţa River. The longitudinal connectivity of this lotic system is interrupted by numerous transversal hydrotechnical works (weirs). This proposed system was designed to facilitate fish migration, promote fish recolonization of upstream and downstream habitats, allow the expansion of fish range, and increase spawning potential. All components of the proposed system are attached to a concrete girder located to the right stream bank, except a glass basin that is submerged in the riverbed. The positioning of the system in this girder ensures its resistance to high water events, while offering safe passage for fish in both directions.

Gravity & wind load analysis and optical study of solar parabolic trough collector with composite facets using optimized modelling approach

In the present work, structural and optical analysis of 23.08 m2 (Aaperture) solar parabolic trough has been done utilizing different composite materials with an optimized modelling approach. The linear parabolic trough collector is subjected to gravity and wind loads and thereby it undergoes surface deformations. Various trough materials are structurally analysed and a hybrid composite is designed. The RMS values of local slope deviations of trough termed as SD value is calculated using Modified Element Approach to observe the behaviour of trough at various tracking positions varying from 0° to 90° orientations. The cases been discussed are trough-alone (stiff) case and full collector (elastic) case under gravity and wind loading conditions with wind speed of 15 m/s. Trough parameters like fibre orientation of laminae, stacking sequence and direction and size of reinforcement conduits are optimized to minimize SD values. Furthermore, the setup is optically studied and the slope deviations are compared for individual models through intercept factors (γ). The comparative study reveals that the solar parabolic trough collector with its facets made of woven jute/glass fibre-reinforced polyester hybrid composite material yields γmax = 0.957 for avg. SD = 1.34 mrad in stiff case and γmax = 0.955 for avg. SD = 1.349 mrad in elastic case under gravity load, and γmax = 0.866 for avg. SD = 3.78 mrad in stiff case and γmax = 0.863 for avg. SD = 3.81 mrad in elastic case under both wind and gravity loads, resulting to be the best among considered models. Maximum weight reduction of up to 30% in stiff case and up to 4.5% in elastic case has also been observed compared to conventional glass collector for hybrid composite model thus reducing the tracking power and producing a cost effective system.

Mathematical Methods for Solar Chimney Analysis

Solar Chimney Power Plants (SCPP) – also known as Solar Updraft Power Plants – consists in a structure composed by a glass collector, placed in a few meters from the ground, with a chimney in its center, in order to promote a pressure differential and consequently a heated air flow. On the bottom of the chimney, a turbine convert the kinetic energy from the heated airflow in electric power. Many mathematical and numerical methods for predict the performance of this kind of renewable energy plant have been conducted, but always with a divergence among them. The main objective of this work is to compare the mathematical methods of evaluation the overall performance, as well to propose a more accurate mathematical method, comparing all results with Manzanares Plant and other methods in the literature. Two approaches were studied and then modified: one based on continuity and momentum equation and the other based on the sum of all pressure drops along the system. The main reasons of the difference between the models analyzed are highlighted. The results shows that one of the proposed methods leads to a divergence of only 1.3% when compared to Manzanares pilot plant, i.e., with an excellent agreement with experimental data.

Pesticide drift from aircraft applications with conical nozzles and electrostatic system

ABSTRACT: Despite all advances obtained with the pesticide use worldwide and in Brazilian agriculture, there is still a lack of technologies for agricultural aircrafts. The objective of this study was to evaluate the drift produced by the use of conical nozzles and electrostatic system in aircraft application. The experimental design was completely randomized with a factorial arrangement and four replications. Treatments included two spraying equipment: electrostatic system with 5L ha-1 of spray volume and conical nozzle with 15 and 20L ha-1. In all treatments, azoxystrobin fungicide was used at a dose of 100g a.i. ha-1 and paraffinic mineral oil at a dose of 0.5% v.v. Volume median diameter (VMD) and droplet density were estimated using water sensitive paper. Evaluations of drift distance were performed with glass collectors distributed horizontally on the soil surface, 50m before the application band, at the application site and 12,5, 25, 50, 75, 100, 150, 200 and 300m after the application site, along the wind direction. Azoxystrobin concentration in glasses were quantified by UHPLC-MS/MS. Results indicated that the drift distance can reach more than 300 meters away from the application site, with variable concentrations according to the equipment used. Electrostatic system reduced drift when compared to hydraulic conical nozzles.

Collection-efficient, axisymmetric vacuum sublimation module for the purification of solid materials.

A vacuum sublimation module of axisymmetric geometry was developed and employed to purify solid-phase materials. The module provides certain practical advantages and it comprises: a metering valve, glass collector, glass lower body, main seal, threaded bushing, and glass internal cartridge (the latter to contain starting material). A complementary process was developed to de-solvate, sublime, weigh, and collect solid chemical materials exemplified by oxalic acid, ferrocene, pentachlorobenzene, chrysene, and urea. The oxalic acid sublimate was analyzed by titration, melting range, Fourier Transform Infrared (FT-IR) Spectroscopy, cyclic voltammetry, and its (aqueous phase) electrolytically generated gas. The analytical data were consistent with a high-purity, anhydrous oxalic acid sublimate. Cyclic voltammograms of 0.11 mol. % oxalic acid in water displayed a 2.1 V window on glassy carbon electrode beyond which electrolytic decomposition occurs. During module testing, fifteen relatively pure materials were sublimed with (energy efficient) passive cooling and the solid-phase recovery averaged 95 mass %. Key module design features include: compact vertical geometry, low-angle conical collector, uniformly compressed main seal, modest power consumption, transparency, glovebox compatibility, cooling options, and preferential conductive heat transfer. To help evaluate the structural (module) heat transfer, vertical temperature profiles along the dynamically evacuated lower body were measured versus electric heater power: for example, an input of 18.6 W generated a temperature 443-K at the bottom. Experimental results and engineering calculations indicate that during sublimation, solid conduction is the primary mode of heat transfer to the starting material.

Predicting the Effects of Sand Erosion on Collector Surfaces in CSP Plants

This paper presents a methodology to predict the optical performance and physical topography of the glass collector surfaces of any given CSP plant in the presence of sand and dust storms, providing that local climate conditions are known and representative sand and dust particles samples are available. Using existing meteorological data for a defined CSP plant in Egypt, plus sand and dust samples from two desert locations in Libya, we describe how to derive air speed, duration, and sand concentrations to use within the Global CSP Laboratory sand erosion simulation rig at Cranfield University. This then allows us to predict the optical performance of parabolic trough collector glass after an extended period by the use of accelerated ageing. However the behavior of particles in sandstorms is complex and has prompted a theoretical analysis of sand particle dynamics which is also described in this paper.

Electrokinetic control of bacterial deposition and transport.

Microbial biofilms can cause severe problems in technical installations where they may give rise to microbially influenced corrosion and clogging of filters and membranes or even threaten human health, e.g. when they infest water treatment processes. There is, hence, high interest in methods to prevent microbial adhesion as the initial step of biofilm formation. In environmental technology it might be desired to enhance bacterial transport through porous matrices. This motivated us to test the hypothesis that the attractive interaction energy allowing cells to adhere can be counteracted and overcome by the shear force induced by electroosmotic flow (EOF, i.e. the water flow over surfaces exposed to a weak direct current (DC) electric field). Applying EOF of varying strengths we quantified the deposition of Pseudomonas fluorescens Lp6a in columns containing glass collectors and on a quartz crystal microbalance. We found that the presence of DC reduced the efficiency of initial adhesion and bacterial surface coverage by >85%. A model is presented which quantitatively explains the reduction of bacterial adhesion based on the extended Derjaguin, Landau, Verwey, and Overbeek (XDLVO) theory of colloid stability and the EOF-induced shear forces acting on a bacterium. We propose that DC fields may be used to electrokinetically regulate the interaction of bacteria with surfaces in order to delay initial adhesion and biofilm formation in technical installations or to enhance bacterial transport in environmental matrices.

Post-chamber inactivation of catalase powder during spray drying in bench-top machines

The kinetics of inactivation of catalase during its residence time in the cyclone separator of two mini-scale spray dryers has been determined. The object was to determine if the catalase shows further inactivation after leaving the drying chamber and residing for up to 10min in the glass collector until the run is complete. Substantial inactivation within the collector of both machines was detected, with an ultrasonic nozzle giving much greater post-chamber inactivation than a two-fluid nozzle. There was a correlation between inactivation rate and the differing drying-air outlet temperatures produced with the two nozzle types only within one machine and not between the two different machines. A kinetic model was derived that describes the degree of inactivation of the product powder in dependence of its residence time in the separator. Non-linear curve fitting of the model to the experimental data gave first-order half-lives on catalase inactivation in the collector of the Büchi of 5.1 and 15.8min for the ultrasonic and two-fluid nozzles, respectively, and in the collector of the ProCept of 5.3 and 16.1min. The lengthy process times required to spray dry large batches of a protein on these mini-scale machines should therefore be avoided.

A Comparison of Polymer Film and Glass Collectors for Concentrating Solar Power

This paper describes work to compare the optical properties and surface texture of glass and polymer film collectors. We also present the results of experiments designed to simulate collector cleaning processes (both contact and non-contact), and the degradation of glass and polymer reflecting surfaces owing to sand and dust abrasion. Finally we present initial results on the applicability of anti-soiling and self-cleaning coatings on glass and polymer film collector surfaces. Measurements, which include specular and hemispherical reflectance, surface roughness, and electron microscopy, indicate the excellent performance of currently available polymer film in terms of its optical performance and robustness in comparison with traditional glass collectors in CSP applications.

Role of light scattering in the performance of fluorescent solar collectors

A fluorescent solar collector (FSC) is a waveguide device that can concentrate both diffuse and direct sunlight on to a solar cell. The electrical output of the device depends strongly on the photon fluxes that are absorbed, emitted, and trapped inside the FSC plate. For this reason, it is important to study the photon transport losses inside the collector. One of the losses in FSC to be investigated is scattering, which increases the probability of the escape cone losses. We determine the scattering contributions in FSC by using angle dependence of light internally reflected in the FSC. The cause of scattering in spin-coated polymethylmethacrylate on top of the glass collector is identified as roughness from the top surface, rather than bulk losses. This loss can be suppressed to less than 2% using an index-matching planarization layer.

Digestibilidade protéica da farinha de resíduos da filetagem de tilápias e farinha de vísceras de aves para o piavuçu (Leporinus macrocephalus)

Knowledge of the digestibility coefficients enables the preparation of rations that meet the nutritional requirements of animals through the knowledge of the use of nutrients in foods. The aim of this study was to determine the digestibility coefficients of crude protein from poultry by-product meal and tilapia filleting by-product meal for piavucu (Leporinus macrocephalus) juveniles. A total of 60 piavucu juvenile with initial average weight of 75.05 ± 12.62 g, were distributed in three collecting tanks with capacity of 90 liters for feces collect. The feeding was carried until the apparent satiety in adaptation phase of 40 days. Four times a day 8h00, 11h00, 14h00 and 17h00. In the feces collection period, the fishes were fed at 8h00, 12h00 and 14h00 controlled, however, from 16h00 to 20h00 were fed until apparent satiety. After 30 minutes of the last feeding were carried out water exchanges and attached at the bottom of the tank, the feces glass collector was placed at 7h00 at the following day. The fish were fed with purified diets, two tests and a reference one. It was observed that the tilapia filleting by-product meal had a higher level of apparent digestibility (89.94%) compared to poultry by-product meal (81.61%). The tilapia filleting by-product meal and the poultry by-product meal are protein foods with excellent rates of protein apparent digestibility and should be utilized for piavucu feeding, aimed formulated cheaper rations that meet the requirements of the species.

An Indirect Passive Solar Dryer for Drying

A solar drying system designed on the principles of convective heat flow, constructed from local materials was employed in drying yam (Dioscorea Alata). A glass collector having an efficiency of about 0.63 was used along with an absorber for absorbing the heat energy. The drying chamber consisted of drying trays. A chimney fitted at the top centre of the drying chamber enhanced airflow. Air passing through the collector heated up and dried the foodstuff in the drying chamber. The latitude of Ilorin is 8.26oN and the collector angle could be varied . 56o C, 41o C and 71o C were obtained as the maximum attainable temperatures for the drying chamber, ambient and collector respectively. Two samples of yam chips, each weighing 1560g and having an average size of 1cm thick, were dried both inside the dryer and outside the dryer within its surrounding. The initial moisture content of the yam was 70.3% (wet basis) and its final moisture content was 9% (wet basis).The result was compared to natural sun drying. It was observed that the drying time was reduced from 52 hours for sun drying to 45 hours for solar drying. The total cost of the construction was 6, 105 Naira.

Processing and immobilization of enzyme Ribonuclease A through laser irradiation

Abstract