Collector Prototype Research Articles

Designing and testing low-cost solar water heater using date palm fibers andstarch.

Solar water heaters are a type of renewable energy technology that converts solar energy into heat to warm water. Solar water heaters are becoming increasingly popular due to their eco-friendliness, cost-effectiveness, and low maintenance requirements. In this study, low-cost solar collectors were developed using date palm waste (dried leaves) as thermal insulation. Date palm waste is a readily available and abundant resource in many regions, and using it in solar collectors can help reduce waste and promote sustainability. Two solar collectors were fabricated using crushed date palm waste, with one collector using the waste alone and the other mixed with starch. Tests were conducted in accordance with the European standard EN 12975-2-2006 and modeled the thermal behavior of the collectors. The results obtained showed that the prototypes of solar collectors performed well and exhibited behavior comparable to that of a commercial solar collector, with a production cost up to three times less. The use of date palm waste as thermal insulation in solar collectors is an innovative approach that aligns with the principles of sustainability and environmental friendliness. Furthermore, it was found that the leveled heating cost (LCOH) and the simple payback period (SPP) were 0.952 US$ kWh-1 and 2.472 years for the prototype without starch and 0.926 US$ kWh-1 and 2.397 years for the prototype with starch.

Thermal and structural response of a pavement solar collector prototype

Thermal and structural response of a pavement solar collector prototype

Design of Solar Collector Prototype with Working Fluid Temperature and Pressure Measurement for Energy Harvesting

Indonesia is a tropical country, which gets a lot of sunshine every year. Harvesting energy from solar heat is an alternative solution to obtain renewable and environmentally friendly electrical energy. The purpose of this research is to design and test the temperature and flow of the working fluid of a solar collector for energy harvesting. The method used is true experiment research by making a solar collector prototype. Measurement of the temperature and pressure of the working fluid is carried out by varying the power of the heating lamp as a substitute for sunlight in the test. The experimental results show that the greater the heat energy received by the solar collector, the higher the temperature of the working fluid and the resulting pressure during the same test. The highest temperature recorded for the liquid coming out of the solar collector reaches 63.6 oC with a maximum pressure difference of 19.6 Pascals. The results of this test will be followed by testing the flow rate of the working fluid to determine the power potential of the working fluid for harvesting energy.
 Highlights:
 
 Efficiency Enhancement: Optimizing solar collector design for increased heat energy absorption and efficient energy conversion.
 Temperature-Pressure Correlation: Investigating the relationship between heat energy, working fluid temperature, and pressure for better energy yield.
 Flow Rate Analysis: Assessing working fluid flow to gauge energy potential and inform effective energy harvesting strategies.
 
 Keywords: solar collector, temperature, fluid pressure, energy harvesting

Experimental Investigation for Augmentation of Thermal Performance of Solar Air Collector

This paper presents a study of the thermal performance of a solar air collector used to heat the drying air of a fruit and vegetable dryer. The prototype collector could be a viable solution to improve energy efficiency and food security in Burkina Faso and other developing countries, by contributing to the reduction of post-harvest losses and the increase of income for local agricultural producers. The collector is first realized by using black painted cans as air ducts, perforated to increase turbulence, and a glass covering the collection surface. After realization, the collector is connected to the dryer and a measurement campaign is conducted to evaluate the thermal performance of it. The measured parameters are the sunshine and the air temperature by keeping the air speed fixed at 0.3 m/s. The analysis of the results shows an important variation of the air temperature difference going from 0.1°C to 74.4°C, between the inlet and the outlet of the collector for an irradiation which varies between 142 W/m2 and 837 W/m2. The black painted surface of the air ducts as well as the increase in turbulence contributed to improve the efficiency of the collector which varies between 0.94% and 50.68% and allowing to record air temperatures ranging from 27.2°C to 69.2°C inside the dryer. This temperature range is favorable for the drying of most food products.

Multi-objective optimization for comparative energy and economic analyses of a novel evacuated solar collector prototype (ICSSWH) under different weather conditions

This paper aims at optimizing the energy performance of an innovative integrated collector-storage solar water heater (ICSSWH) prototype. The system incorporates a high-vacuum gap, which significantly reduces convective thermal losses, and a serpentine absorber system coated with a low-E layer to minimize radiative thermal losses.The methodology is based on a detailed dynamic simulation model, implemented in the MatLab environment, suitable conceived to accurately predict the energy performance and economic profitability of the ICSSWH under various weather conditions and energy market prices. This approach aims to initially identify the most influential geometrical, thermophysical and optical parameters that impact the energy performance of the system through the assessment of different objective functions. After identifying the most influential parameters, the range of existence with the interval step for each variable is defined, and the optimization procedure is conducted to determine the optimal set of variables that maximize/minimize the selected objective functions.To demonstrate the effectiveness of the proposed methodology, a proof of concept was conducted to optimize the energy performance of novel ICSSWH by considering nineteen parameters with the aim of maximizing/minimizing three different objective functions. The results of this analysis yielded various sets of optimised parameters for the ICSSWH. Therefore, by implementing the set of optimised parameters into the dynamic simulation model, the energy performance of the optimised and non-optimised ICSSWH collectors was evaluated in 42 different weather zones and compared to a reference case scenario.

Investigation of a Linear Fresnel solar collector (LFSC) prototype for phosphate drying

Drying is an energy intensive process, which requires a high amount of thermal and electrical energy. To respond to that challenge, this paper proposes an innovative phosphate dryer environment friendly. The idea is to exploit the Linear Fresnel Solar Collector (LFSC) in the drying process. A laboratory scale prototype was designed and constructed based on a detailed theoretical and optical study. The numerical results prove that the designed prototype admits a significant optical efficiency which can reach values higher than 0.7 from May to July. An adjustment of LFSC prototype mirrors by laser beam allows good optical performances suitable for phosphate drying. The experimental results showed that the residual humidity of the dried phosphate was in the order of 0.02 kg water/kg dry matter in the LFSC process and 0.07 kg water/kg dry matter in the open air process, after 04 h 40 min. The drying process using LFSC has reached international phosphate marketing standards. Based on 100 m2 LFSC aperture area, the yearly provided thermal energy was 59,766 kWh, the largest quantities of dried phosphate are obtained during the summer with a maximum of 43 tons in July and the dodged CO2 emissions are about 38,255 kg.

Evaluation of the incidence of optical and physical characteristics on the performance of a Fresnel Linear Collector prototype

Evaluation of the incidence of optical and physical characteristics on the performance of a Fresnel Linear Collector prototype

Ionic Wind Driven Fog Collection in Windless Environment

Fog collection is a promising technique to harvest water from the atmosphere. However, the fog collection in the windless environment is still a challenge. An ionic wind-driven fog collector was numerically designed. Numerical results demonstrated that the discharge electrode location significantly influenced the ionic wind flow pattern and fog collection rate. The fog collection rate corresponding to a nearly unidirectional flow pattern was several times of that corresponding to the vortices dominant flow pattern. An enhancement of 6.7 times in the fog collection rate was realized by increasing the input power. The fog collection rate increased linearly with the liquid water content under a fixed power consumption. A fog collector prototype was fabricated. The measured ionic wind velocity and fog collection rate supported the numerical design. In a windless foggy environment with a liquid water content of 0.62 g m–3, a collection rate of 0.46 L h–1 was achieved.

Measuring Concentrated Solar Radiation Flux in a Linear Fresnel-Type Solar Collector

Linear Fresnel solar collectors are a promising and emerging solution to contribute to renewable heat supply in industrial processes with thermal energy demand in the medium temperature range (<250 °C). An innovative linear Fresnel collector (LFC) prototype has been designed, patented, and built at the Plataforma Solar de Almería (PSA), Spain. This work presents the applied methodology, experimental device, and results obtained in the measurement of the flux density of concentrated solar radiation in the focal plane of the solar collector. The experimental results confirm that an average flux density of (9.8 ± 0.6) kW/m2 was obtained with a direct normal solar irradiance of (870 ± 10) W/m2 in tests performed in May 2002, which is a result similar to that obtained in optical simulations of the system.

Ultrahigh-efficiency solar energy harvesting via a non-concentrating evacuated aerogel flat-plate solar collector

Non-concentrating solar collector is extensively used in residential and industrial sectors for low-temperature (<120 °C) applications. The current non-concentrating solar collectors are underperformed in the intermediate temperature range (120–300 °C), which immensely limits their application. In this paper, a structure-optimized evacuated flat plate solar collector with a transparent aerogel layer and back shield plate is proposed to solve the above issue. The experimental test is conducted to validate the numerical model of the evacuated flat plate solar collector and the spectral properties of the transparent aerogel layer. The analysis results manifest that the structure optimized evacuated aerogel flat-plate solar collector possesses ultrahigh thermal efficiency in the low and intermediate temperature range with a relatively thin aerogel layer (5 mm) adopted and it is superior to state-of-the-art work. The thermal efficiency of the evacuated aerogel flat-plate solar collector is 60.47% at an inlet temperature of 155 °C, which is a 20.68% enhancement over that of the prototype collector. This research is fundamental to the future development of non-concentrating solar collectors and instrumental in the decarbonization goal for residential buildings and industrial heating energy supplements.

Thermal performance of a controllable pavement solar collector prototype with configuration flexibility

Solar energy harvesting as a renewable and sustainable energy source has been widely investigated in recent years across engineering fields. The use of Pavement Solar Collectors (PSC) can lead to clean energy production, an increase in road safety, prolong the service life of asphalt pavement, and can mitigate the Urban Heat Island (UHI) effect. This study describes a controllable large-scale research PSC prototype with high configuration flexibility, and full monitoring capability at the University of Antwerp, Belgium. Since small- or laboratory-scale setups do not reflect the behavior of actual projects, the present paper investigates the thermal response of a large-scale PSC in the Western European climate, including heating load, heat extraction capacity, and asphalt surface and profile temperature changes during heating and cooling experiments.The study shows that a low supply temperature compared to high (14 °C vs. 28 °C) can reduce the depletion rate of the stored thermal energy in borehole thermal energy storage up to 7 times. The sensitivity analysis indicates that an increase in flow rate from laminar to transient regime requires twice as much thermal power compared to the same flow rate changes within transient and turbulent regimes. The maximum average daily efficiency of the PSC could reach 34% with a flow rate of 4 l/min. The experimental results showed that increasing the pipe length from 50 m to 200 m reduces the cumulative power extraction capacity by up to 48%. Furthermore, the PSC system shows great potential in reducing the asphalt surface temperature (up to 12 °C) to mitigate the UHI effects. Finally, the PSC system effectively controls the temperatures of the interface zones to reduce the rutting distress in the summertime and lower the potential of cold thermal crack developments and brittle shear failure behavior in wintertime.

Dynamic simulation and thermal investigation of a PTC for building integration under the climatic conditions of South eastern MOROCCO

This paper aims to report a detailed study of a Parabolic Trough Collector (PTC) prototype’s thermal system that requires a sizing and dimensioning investigation of its main parts. This PTC system possesses a field-type evacuated tube solar collector with U-shaped. Furthermore, a simulation study developed with TRNSYS is carried out to evaluate the validity and the feasibility of this system, in particular, for the low-temperature range. The solar collector is oriented to the south and follows the sun from east to west through a single-axis tracking system under real weather conditions. From the simulation results we noticed that for the operating configuration considered in this study, the solar fraction is significantly large throughout the year. During the summer, needs are covered almost 100 %. Whereas, it is necessary to integrate an auxiliary system for the winter period. The tank temperature reached a maximum of around 90 °C during the summer period. The system constantly ensures a heated floor temperature of around 28 °C. This reported simulation and analysis may enable to design and estimate of the region potential and the system productivity over the year, for different applications such as heating domestic water and underfloor systems.

The Development History and Latest Progress of Deep-Sea Polymetallic Nodule Mining Technology

Deep-sea polymetallic nodules are a mineral resource with potential for commercial development. Due to the unique deep-sea environment in which they are found, specialized technology and equipment are required for their extraction. In this paper, firstly, the development of deep-sea polymetallic nodule mining technology is classified into three stages, and its characteristics are summarized. Moreover, the results from research into deep-sea polymetallic nodule mining technology are analyzed, including proposals for mining systems, research into key technologies, basic scientific problems, and proof of technical feasibility from sea tests. Secondly, the testing of the collector prototype and the environmental impact assessment study of Global Sea Mineral Resources NV, as well as the progress of the deep-sea polymetallic nodule mining test project in China, are introduced. On this basis, the opportunities and challenges brought by the fast-growing demand for electric vehicles to the development of deep-sea polymetallic mining technology is analyzed, and a possible technical scheme for a mining system and the trends in its development towards high reliability and high standards of environmental protection according to the requirements of commercial exploitation are explored. This provides a reference for the research and development of high-efficiency technology and equipment for the mining of deep-sea polymetallic nodules.

A prototypal high-vacuum integrated collector storage solar water heater: Experimentation, design, and optimization through a new in-house 3D dynamic simulation model

Integrated collector storage units are typically affected by convective and radiative heat losses which significantly reduce their energy performance. To enhance solar collection and heat retention, innovative techniques and novel design of such units are being more and more developed. In this framework, this paper focuses on the design and optimization of a prototypal high-vacuum integrated collector storage solar water heater. The proposed unit allows for reaching high temperatures of the stored water and for reducing the temperature drop during non-collection periods. This goal is achieved by suppressing the convective heat losses into the system by keeping the pressure into the related enclosure below 0.01 Pa and by applying a special selective coating to the solar absorber surface to drastically reduce radiative losses as well.In this paper, details about the system design and the conducted experimental tests are reported. In addition, a new mathematical model able to assess the energy performance of the innovative prototype is presented. This tool, based on a detailed 3-D transient finite-difference thermal network, was validated against the gathered experimental data. By such a tool the optical properties of the adopted selective coating are optimized for maximizing the system thermal efficiency. Finally, with the twofold aim of showing the potentiality of the developed code, as well as the effectiveness of the presented innovative solar collector prototype, a comprehensive case study referred to three different European weather zone is presented. Promising results in terms of energy savings (0.73 MWh/y) and CO2 emission reduction (149 kgCO2/y) are achieved.

Experimental study of a newly developed dual-purpose solar thermal collector for heat and cold collection

A Flat Plate Solar Collector (FPSC) is a commonly used device to harvest solar energy. An FPSC is typically covered on top with a single-pane glass, known as a glazed FPSC. A conventional glazed FPSC is generally used only for heat collection. The purpose of this paper is to describe an innovative design of a dual purpose solar thermal collector that is able to utilize sustainable energy, i.e., solar heat and night sky cooling, to accomplish heat and cold collection. In this proposed collector, a double-pane “window” was used on the top of an FPSC to replace the conventional single-pane glass cover, which allows water or other liquid flowing in the space between the two panes to lose its heat to carry out cold collection through both long-wave radiation and convection. The measurement results obtained from a real-world experiment on a prototype collector indicate that the developed collector is not only able to retain the functionality of a conventional glazed FPSC for heat collection with the tested heating power of 505 ± 7.8 W/m2, but also to have an additional ability for cold collection with enhanced cooling power (321 ± 5.0 W/m2) and cost-effectiveness compared with conventional unglazed FPSCs, photovoltaic-thermal (PVT) collectors, or the devices using daytime radiative cooling materials.

Life Cycle Assessment of the Use of Phase Change Material in an Evacuated Solar Tube Collector

This paper presents an environmental impact assessment of the entire cycle of existence of the tube-vacuum solar collector prototype. The innovativeness of the solution involved using a phase change material as a heat-storing material, which was placed inside the collector’s tubes-vacuum. The PCM used in this study was paraffin. The system boundaries contained three phases: production, operation (use phase), and disposal. An ecological life cycle assessment was carried out using the SimaPro software. To compare the environmental impact of heat storage, the amount of heat generated for 15 years, starting from the beginning of a solar installation for preparing domestic hot water for a single-family residential building, was considered the functional unit. Assuming comparable production methods for individual elements of the ETC and waste management scenarios, the reduction in harmful effects on the environment by introducing a PCM that stores heat inside the ETC ranges from 17 to 24%. The performed analyses have also shown that the method itself of manufacturing the materials used for the construction of the solar collector and the choice of the scenario of the disposal of waste during decommissioning the solar collector all play an important role in its environmental assessment. With an increase in the application of the advanced technologies of materials manufacturing and an increase in the amount of waste subjected to recycling, the degree of the solar collector’s environmental impact decreased by 82% compared to its standard manufacture and disposal.

Numerical simulation and experimental characterization of the heat transfer in a PV/T air collector prototype

PV/T systems are an emerging technology for the simultaneous production of electrical and thermal energy. In this paper, we present an experimental device modified with an arrangement of aluminum square tubes to remove thermal heat from the system and increase its electrical efficiency. A 1D analysis allowed prediction of the heat transfer in the solid components. Moreover, a 3D simulation allowed visualization of the temperature distribution in the prototype. The simulations considered the surrounding temperature, the solar irradiance and the airflow velocity inside the square tubes. The glass temperature, PV cell temperature and the outlet airflow temperature were logged. The study was performed at a low airflow (0.5 m/s) and at a high airflow (2 m/s); for both experiments, the maximum solar irradiance was 800 W/m2 and the heat fluxes were calculated. The time constant was shorter for the experiment at low airflow, because the airflow increased by 63.2% at 5400s. At a high airflow, it took 9100 s to achieve the 63.2% of the maximum increase, and the difference between the outlet temperature and the temperature of the surrounding air was significantly reduced. At 0.5 m/s and 2 m/s the PV cell reached a maximum temperature of 75 °C and 59 °C, respectively. The maximum difference in temperature between the two experiments was 20 °C. The best thermal average efficiency was 42.5%, corresponding to the high airflow experiment. Furthermore, based on the favorable air outlet temperature, at this flow rate, the outlet air could be used for drying in a subsequent process.

Demonstration of a novel instrument for online monitoring of absorber emissions to air

A novel concept for online monitoring of nitrosamines, solvent amines and their degradation products in amine absorber emissions to air was demonstrated at the Tiller CO2-lab pilot facility. The monitoring concept is based on SINTEF patent No. PCT/EP2011/073557. The measurement method applies gas sampling by capture of analytes in a condensate stream from a single stage condensate collector unit. An improved design for the SINTEF prototype for online gas and liquid measurements has been established as part of the CCUS-ALIGN project. The new design has low complexity and improved robustness, making it applicable as integrated part of industrial monitoring systems. The established prototype was successfully tested for monitoring of trace gas emission from a CO2 capture pilot plant, demonstrating measurements of nitrosamines at levels far below the lower detection limits of commercial industrial online analyzers. Results from testing of a condensate collector prototype indicate high capture efficiency for analytes of interest, including analytes present in aerosols during operation conditions where the absorber emit mist to the atmosphere. The measurement concept has potential for significantly reducing the costs related to manual gas measurements for critical trace gas components in plant operation. Application of the concept can enable continuous measurements of nitrosamines and other critical trace gas analytes in the emissions to air not currently available in absorption-based CO2 capture processes.

Demonstration of a Novel Instrument for Online Monitoring of Absorber Emissions to Air

A novel concept for online monitoring of nitrosamines, solvent amines and their degradation products in amine absorber emissions to air was demonstrated at the Tiller CO2-lab pilot facility. The monitoring concept is based on SINTEF patent No. PCT/EP2011/073557. The measurement method applies gas sampling by capture of analytes in a condensate stream from a single stage condensate collector unit. An improved design for the SINTEF prototype for online gas and liquid measurements has been established as part of the CCUS-ALIGN project. The new design has low complexity and improved robustness, making it applicable as integrated part of industrial monitoring systems. The established prototype was successfully tested for monitoring of trace gas emission from a CO2 capture pilot plant, demonstrating measurements of nitrosamines at levels far below the lower detection limits of commercial industrial online analyzers. Results from testing of a condensate collector prototype indicate high capture efficiency for analytes of interest, including analytes present in aerosols during operation conditions where the absorber emit mist to the atmosphere. The measurement concept has potential for significantly reducing the costs related to manual gas measurements for critical trace gas components in plant operation. Application of the concept can enable continuous measurements of nitrosamines and other critical trace gas analytes in the emissions to air not currently available in absorption-based CO2 capture processes.

Radiation tests of the prototypes of the fiber-optic collector for ITER plasma diagnostics

Fiber bundles will be subjected to gamma-neutron irradiation in ITER Port Interspace & Cell areas, and the highest radiation dose will be accumulated in their head parts (collectors). Radiation tests have to be done to prove their radiation hardness. The paper is devoted to the radiation test of the fiber-optic collector prototypes at Co-60 gamma source. The collectors were manufactured using Epo-Tek 353ND optical glue, which is intended for a long-term use at temperatures up to 300 °C (decay temperature 412 °C). The irradiation was performed in the Kurchatov Institute in the continuous mode of the Co-60 gamma source. The aim of the tests was to investigate the influence of gamma-irradiation on the samples’ transparency and integrity. The test results showed that the fiber collector prototype based on silica fibers and EPO-Tek 353ND epoxy has a sufficient radiation resistance after the irradiation up to dose of a few kGy.