Small Collector Research Articles

Early life stages of the invasive Atlantic blue crab Callinectes sapidus in the Western Mediterranean Sea

The early life cycle of the Atlantic blue crab Callinectes sapidus includes seven zoeal stages that develop in coastal waters, and a later megalopal stage that colonizes estuaries. Although these stages have been largely studied in native ecosystems, very little is known about larval patterns in smaller-scale, invaded, estuarine environments such as those available in the Mediterranean Sea. The general aim of this study is to assess the distribution and abundance of early life stages of C. sapidus in the communication channels of the Albufera lagoon with the Mediterranean Sea, and in adjacent coastal waters. Different sampling methods were employed to target each life stage. (1) For zoeae, planktonic tows were conducted using a 300 μm manta net along 200 m transects parallel to the coastline at distances of 300, 1000 and 3000 m from the shore. (2) A small and manageable passive collector model was used to capture megalopae and juveniles in estuarine areas. This system was first tested from 2020 to 2021 in a single channel, with a weekly sampling frequency, and two more channels were added in 2022. Additionally, intensive daily sampling was conducted in one of the channels from September to November 2022 during the settlement peak. Results showed that zoeae of C. sapidus were more abundant in August 2021, at 1000 m from the coast, and appear to have a disjoint temporal distribution with zoeae of other crab species. Megalopae and juveniles were more abundant from September to November at all sampling sites and times. In 2022, collectors featured a dominance of megalopae at two of the sites (ca. 73%), while the site with the lowest salinity showed a dominance of juveniles (84%). For megalopae, comparative results from the intensive and the regular sampling campaigns showed that time of residence within collectors is just a single day. For juveniles, higher numbers were detected with increased deployment time, suggesting a need for enhanced habitat complexity.

Efficient Production of Doughnut-Shaped Ce:Nd:YAG Solar Laser Beam

Laser beams with a doughnut-shaped profile have garnered much attention for their contribution to trapping nanoparticles and improving the scanning speed during laser-based 3D metal printing. For this reason, the production of a doughnut-shaped solar laser beam by end-side pumping a Ce:Nd:YAG rod with a small reflective parabolic collector was investigated. The resultant beam profile shape depended on the absorbed solar power, displaying a TEM00-mode profile at elevated input power. This phenomenon was primarily attributed to the role of distributing energy around the central region of the crystal. In contrast, at lower input power, a doughnut-shaped beam emerged, characterized by minimal energy distribution at the center. Through experiments conducted with a collection area of 0.226 m2 and a nominal solar irradiance from 970 W/m2 to 1000 W/m2, it was demonstrated that sufficient energy was available to generate a doughnut-shaped beam with a solar laser collection efficiency of 5.96 W/m2, surpassing previous measurements by 1.32 times. Further research with a larger collection area of 0.332 m2 and a diverse solar irradiance range of 650 W/m2 to 800 W/m2 revealed that the presence of a thin layer of cloud caused a transition from a doughnut-shaped to a TEM10-mode and, eventually, a TEM00-mode as the absorbed input solar power increased. Notably, under heavier cloud cover, the laser beam exhibited deformation at low input power instead of maintaining a doughnut-shaped profile. This research significantly enhances our comprehension of doughnut-shaped solar laser beams and their reliance on solar energy. By harnessing the plentiful and readily accessible energy from the Sun, the incorporation of solar energy into the realm of solar-pumped lasers holds immense promise for promoting sustainability. This transformative utilization can progressively diminish the industry’s carbon footprint, yielding long-term environmental benefits.

Refining and Pyrolysis Oil of Co-glycerol from Biodiesel Fuel (BDF) Production using Small solar Thermal Collector

Refining and Pyrolysis Oil of Co-glycerol from Biodiesel Fuel (BDF) Production using Small solar Thermal Collector

Refining and Pyrolysis Oil of Co-glycerol from Biodiesel Fuel Production using small Solar Thermal Collector

Refining and Pyrolysis Oil of Co-glycerol from Biodiesel Fuel Production using small Solar Thermal Collector

Analisis Efisiensi Saluran Tataniaga Biji Pinang Kering di Kecamatan Kuala Kabupaten Nagan Raya

The purpose of this study was to determine the pattern of commerce and efficiency of the business channel of dried betel nut in Kuala District, Nagan Raya Regency. Data were collected by conducting direct interviews with farmers, small collector traders (PPK), and large collector traders (PPB). Data analysis uses Structure, Conduct, and Performance approaches. The overall market structure in the betel nut business process in Kuala District tends to lead to a monopsony market structure. Seeing that the number of sellers and buyers is not balanced, the betel nut business system in Kuala District is inefficient, because it refers to the monopsony market structure. Of the three commercial channels, the most efficient commercial channel is channel I because it has the lowest margin value and the highest farmer's share so that from the farmer's side, the share of prices received by farmers is quite large.

Refining and Production of Pyrolysis Oil of Glycerol derived from Biodiesel Fuel Production using small Solar Thermal Collector

Refining and Production of Pyrolysis Oil of Glycerol derived from Biodiesel Fuel Production using small Solar Thermal Collector

"Optimization of Solar Collector Size to Achieve The Heat Requirement Along Certain Period".(Dept.E)

This paper presents a complete analysis and a numerical application for deducing the optimum solar collector size to satisfy the heat requirement per year for certain estimated life-time of the heating system. Total cost of the heating systems (collector and auxiliary one) is computed for various collectors areas. The collectors area corresponding to the minimum total cost yields the optimum collector size. This goal is very significant since with increasing collector size, the solar contribution will be greater but certain heat collected will wasted if there is no simulataneous demand. On other hand, it is unequivocal that a small collector of only a few square meters would be utilized all year round. Various collector cost functions are assumed to establish its influence on both optimum and maximum collector size beyond which the estimated life-time cost would be more than a conventional one.

Design Optimization and Experimental Validation of Low-Cost Flat Plate Collector Under Central Qasssim Climate

In Saudi Arabia, hot water for domestic uses consumes a great portion of home electricity. Thus, solar collectors can be considered as an important alternative to reduce the amount of consumed electricity. Therefore, in recent researches, a great attention was given to develop flat plate collector (FPC) with optimal performance. In this paper, a multi-objective modified imperialist competitive algorithm (MOMICA) was employed for optimizing the performance of a FPC. The optimization results showed a capability to reach higher FPC efficiency with a relatively small collector area and hence lower price. It has also been proved that the change of the insulator depth from 0.02 to 0.05 m has a strong influence on the system’s efficiency.

Modeling and performance evaluation of a small solar parabolic trough collector (PTC) for possible purification of drained water

Small-scale solar thermal contaminated water purification is a promising green energy based decentralized process especially for rural area. The present work describes thermal performance estimation of a Parabolic Trough Collector (PTC) suitable for contaminated water purification. Contaminated drain water is pressurized through a slow sand filter and PTC with glass cover enclosing a copper tube. The diameter of the copper tube was estimated as 26 mm and that of the glass cover was 50 mm. The rim angle and width of the parabola were 60° and 1.2 m respectively. The PTC focal length, concentration ratio, overall heat loss coefficient was 493.4 mm, 13.93 and 7.39 W/m2K respectively. The maximum modeled and experimental thermal efficiency were about 60% and 55% respectively. Around water flow rate of 0.002 kg/s and solar radiation 750 W/m2, both water temperature and useful heat gain were maximum. The exergetic efficiency of the system increases with the increase of inlet temperature of water for different solar intensity. The solar purified water had all other parameters within acceptable limit except residual chlorine (0.24 mg/L).

Market Analysis of Patchouli Oil in Aceh Jaya Aceh Province

Patchouli from Aceh is a source of patchouli oil producer with the best quality in the world. Aceh Jaya is one of the areas that is very suitable for the development of patchouli cultivation in Aceh and produces patchouli oil which exported to abroad. In the marketing process will involve institutions marketing institutions whose role is to convey the results of production from producer farmers to consumers. This research was conducted to determine the structure, behavior and performance of the patchouli market in the patchouli marketing process in Aceh Jaya. The method used was in-depth interviews assisted by questionnaires to be analyzed in a qualitative description by using Concentration Ratio for The Biggest Four (CR4). The results of the study showed that, the patchouli oil market structure in Aceh Jaya was highly concentrated and leads to monopoly, while the behavior of marketing institutions in determining the choice of patchouli oil marketing channels in Aceh Jaya was divided into 3 types namely, channel 1: farmers- small collectors-cooperatives-exporters-consumers; channel 2: farmer – small collector- bog collector- exporter-consumer; channel 3: farmer-cooperative-exporter-consumer. Judging from the marketing margin and farmer's share, the most efficient market performance was channel 3.

Numerical assessment of the dynamic behavior of a solar-driven jet-ejector refrigeration system equipped with an adjustable jet-ejector

Abstract In the present paper, the mid-term performance of two different architectures of a solar-driven jet-ejector refrigeration system is numerically compared: the first one is fitted with a fixed-geometry jet-ejector while the second one is equipped with an adjustable spindle that modifies the jet-ejector area ratio. The jet-ejector behavior has been predicted with a validated computational fluid dynamics approach and the dynamic response of the overall system accounts for transient effects in a small parabolic trough collector and a hot thermal storage tank. The investigation shows that the adjustable jet-ejector allows for continuous and smooth operation in a much wider range of outdoor conditions. Additionally, it enables more efficient management of the thermal level in the hot storage system. As a result, the adjustable refrigeration system improves the performance indicators in all the warm months of the typical meteorological year under evaluation. The maximum improvement potential is found in May; the fixed-geometry system provides an average C O P th of 0.34 while the adjustable system reaches an average C O P th of 0.48 considering the same boundary conditions in both cases.

Energy Analysis of a Novel Ejector-Compressor Cooling Cycle Driven by Electricity and Heat (Waste Heat or Solar Energy)

Low-grade heat is abundantly available as solar thermal energy and as industrial waste heat. Non concentrating solar collectors can provide heat with temperatures 75–100 °C. In this paper, a new system is proposed and analyzed which enhances the electrical coefficient of performance (COP) of vapour compression cycle (VCC) by incorporating low-temperature heat-driven ejectors. This novel system, ejector enhanced vapour compression refrigeration cycle (EEVCRC), significantly increases the electrical COP of the system while utilizing abundantly available low-temperature solar or waste heat (below 100 °C). This system uses two ejectors in an innovative way such that the higher-pressure ejector is used at the downstream of the electrically driven compressor to help reduce the delivery pressure for the electrical compressor. The lower pressure ejector is used to reduce the quality of wet vapour at the entrance of the evaporator. This system has been modelled in Engineering Equation Solver (EES) and its performance is theoretically compared with conventional VCC, enhanced ejector refrigeration system (EERS), and ejection-compression system (ECS). The proposed EEVCRC gives better electrical COP as compared to all the three systems. The parametric study has been conducted and it is found that the COP of the proposed system increases exponentially at lower condensation temperature and higher evaporator temperature. At 50 °C condenser temperature, the electrical COP of EEVCRC is 50% higher than conventional VCC while at 35 °C, the electrical COP of EEVCRC is 90% higher than conventional VCC. For the higher temperature heat source, and hence the higher generator temperatures, the electrical COP of EEVCRC increases linearly while there is no increase in the electrical COP for ECS. The better global COP indicates that a small solar collector will be needed if this system is driven by solar thermal energy. It is found that by using the second ejector at the upstream of the electrical compressor, the electrical COP is increased by 49.2% as compared to a single ejector system.

Design optimization, fabrication, and performance evaluation of solar parabolic trough collector for domestic applications

ABSTRACT In this paper, a brief study of small scale solar parabolic trough collector design, simulation, fabrication, and analyzed for heating water as a domestic purpose in the backward regions of developing countries are studied. During the designing phase, the solar parabolic trough collector aperture area was set as 1.5 m2 with 1 m wide and 1.5 m length. The design was done by using red laser light (631 nm) and stainless steel ruler template technique, then verified this design template with parabolic equation. After that, optimize the proposed design through Matlab simulation. Then fabricated the proposed design with different manufacturing techniques. Different experiments were conducted to analyze and evaluate the overall thermal performance of 1.5 m2 solar parabolic trough collector by placing it in two orientations i.e. East-West and North-South with respect to the sun tracking. The data were recorded and analyzed to check the overall efficiency and thermal performance of the system. The experimental results evaluated that efficiency and thermal performance of the solar parabolic trough collector was more when the focal line of the designed trough collector was placed in the East-West (61.66%) direction as compared to North-South direction (48.28%). Moreover, the designed collector raised the temperature of 100 liter water up-to 60°C within 5 hours of sunshine which is enough for four to five persons for bathing and laundry purposes in the winter season of backward and rural areas where there is a shortage of electricity and fossil fuels for domestic applications.

Thermo-economic and exergy analysis and optimization of small PTC collectors for solar heat integration in industrial processes

This work presents an extensive analysis of the impact of operating and design parameters on thermo-economic and exergy performances of Small Parabolic Trough Collector (SPTC). The modeling equations system is developed based on thermodynamics and heat transfer phenomena, and it is resolved using a double fixed-point iterative algorithm and validated using experimental data from the literature. Moreover, an optimization work complete this study by using a new combined Fixed Point-Genetic Algorithm optimization method considering Rabat region (North: 34°00′47″, West: 6°49′57″-Morocco) as a case study. The objective function is expressed in such a way to minimize the total yearly cost of energy and maximize the collector exergy efficiency of the SPTC. The obtained outcomes of this work show that thermo-economic and exergy performances of the SPTC could be improved by reducing the collector length and receiver diameter and increasing the collector width. However, the mass flow rate of the heat medium impacts these performances differently. The optimization results prove that the integration of SPTC in industrial heat processes is a promising and very economical way to replace fossil fuels. Indeed, each single optimized SPTC (Aa = 10 m2; Width*Length = 2 m × 5 m) provides more than 12.84 MWh/year with an average unit cost less than 0.022 USD/kWh.

A small parabolic trough collector as a solar water heater: an experimental study in Ouargla region, Algeria

This study aims to conduct an experimental thermal examination of a parabolic trough collector in Ouargla region at Algeria, which will be used as a solar water heater. The solar collector was manufactured and then experimentally tested, as its theoretical optical performance was estimated at 75.06%, while the values of its true thermal performance are 10.61, 10.68 and 8.85 % for 13 May, 14 May and 15 May. Although its thermal performance is somewhat low, the studied PTC is effective in heating the water, whereas, using a volumetric flow of 0.011 l/s, about 317 liters of water can be heated daily at 42°C, knowing that the daily average consumption of hot water in a typical house is 250 liters because the Ouargla region is strategically located that receives huge amounts of solar irradiance

Design of a small size PTC: computational model for the receiver tube and validation with heat loss test

In EU, the residential sector is responsible for the 40% of the total energy consumption. The integration of solar technologies in buildings is therefore necessary in order to reduce the use of fossil fuels. Concentrating collectors could offer an interesting solution but nowadays their application in buildings is rare due to high costs, large dimensions and complexity of the system. A novel small parabolic trough collector (PTC) has been conceived to overcome these limits and to allow the integration in buildings. The main features of realized prototype are the compact dimensions, strongly reduced compared to the PTC standards, and modularity. The paper deals with the numerical analysis necessary to design the concentrating collector properly and its validation with experimental results. An optical analysis has allowed to select the optimum values for the parameters of the parabola, aperture and rim angle. A thermo-fluid dynamics finite element model has been developed with Comsol Multiphysics, to analyse the relevant physical characteristics and to predict the performance of the receiver tube. The efficiency curve of the collector has been extracted. Successively a receiver tube has been built based on the indications of FEM model for what concerns geometry and materials. In order to evaluate the heat loss of the receiver and to validate the finite element model, a test bench has been realized. The results of off-sun heat loss tests on the receiver tube are reported for several temperatures. The computational model is in good agreement with experimental results and therefore it is validated.

Design of a concentrating solar thermal collector installation for a hotel complex in Gran Canaria

This paper deals with the design and configuration of a thermal solar installation adapted to a hotel complex in the south of the island of Gran Canaria (Canary Islands, Spain). The solar collectors are concentration cylinder parabolic of small dimension. The design and calculations are principally performed in order to study the viability of the thermal solar technology of concentration opposite to other technologies of existing renewable energies such as solar thermal plane collectors or solar photovoltaic. Based on the total energy demand and the available solar power capacity (limited by the available surface), the study of the implementation and integration of the installation with previous hotel energy facilities is carried out. The energy production amounts to 45.08 MWh/year in a surface of 40 m2. The study of its economic feasibility has also been performed. This project has been the first small scale cylinder parabolic solar collector installation proposed in the Canary Islands. This way, the use of thermal solar concentration technology is promoted in this area, leading to a major sensibility with the use of affordable, clean, and renewable energies.

THERMAL ENERGY GENERATION FROM A SOLAR COLLECTOR PARABOLIC DISH REFLECTOR

A prototype of a small modularity parabolic dish reflector or PDR solar collector with two-axis solar tracking system was designed and built at the National Polytechnic Institute (IPN) in MA©xico. The purpose is to generate high temperature thermal energy for application in services of small and medium industry as well as domestic uses. The solar tracking in two-axis was developed based on angular relationships and a control system with proportional-integral action so that even when there is an obstruction of solar radiation either by cloud cover, buildings, trees or any other object that generates shade, the collector remains oriented towards the Sun. For operating and monitoring the prototype, a flow control module and a human machine interface or HMI were developed and implemented, allowing by means of a computer interface, the monitoring of solar radiation, temperature for thermal evaluation. The experimental data obtained indicated that the prototype can generate 30 kg of steam saturated starting from water at an ambient temperature of 298 K.

Design and simulation of a concentrated solar thermal system with an integrated concrete storage for continuous heat supply

In this paper a feasibility study to use concentrated solar systems in combination with concrete storages for process heating is shown. As a process example a pasteurization process is examined in which the burner in the process is replaced or modified by the solar thermal system. The utilization of small Parabolic Trough Collector (PTC) and Compound Parabolic Concentrator (CPC) as heat sources is compared. Furthermore the usage of concrete storages for two different scenarios in four countries with different boundary conditions is investigated. A dynamic investment calculation is used to determine the amortization period which shows a outstanding value for most selected places. The results of the study show that the application of CPC below 180°C can achieve better outcomes compared to PTC from both the technical and the economical point of view.

Apparent motion as hyperacuity phenomenon under low two-point spatial resolution

This work presents numerical simulations and experimental validation aimed at optimizing the design of large size flat-plate solar collectors (has a profile area of 10.04 m2). The large size collector with the advantages of high land use efficiency, compact structure, better thermal insulation and simple connection, are widely used in large scale heating systems (like seasonal storage system). Consequently, the study and optimization (thermal and antifreeze performance) of the large size collector are essential for the further application of the large size collector. However, unlike the conventional small collector, the large size collector has high flow and temperature ununiformity. The study of the large size collector should be treated differently with the conventional small collector. Meanwhile, the thermal stress induced by the temperature inhomogeneity should be studied. In this paper, we propose a numerical model of a double-glazed large size collector to evaluate the influence of the design parameters (type of absorber strips, aspect ratio, airgap thickness, number of pipes) on its thermal performance and antifreeze performance. A water-heating system with a large size solar collector is built and tested to validate the simulation model. A mechanical model is present to evaluate the thermal stress of the large solar collector and factors influencing the thermal stress of the large size collector are studied.