Solar Collector System Research Articles

Modelling and analysis of a novel production process of high-pressure hydrogen with CO2 separation using electrochemical compressor and LFR solar collector

Hydrogen as an alternative fuel has a very promising future. Using renewable solar energy to produce green hydrogen is one of the most interesting approaches due to its environmental friendliness. In this study, a novel system configuration is designed and studied that includes electrochemical compressor (EHC), hybrid thermionic-thermoelectric converter (TIG-TEG), and a solar linear Fresnel collector system (LFR). The EHC can produce a hydrogen product at a high pressure with a high purity. Moreover, using a 50/50 H2–CO2 feed a pure CO2 byproduct can be separated from the process. A detailed mathematical modelling considering several key phenomena of the EHC and the TIG-TEG converter is presented with a full variable list that haven't been reported to such extent yet. Simulation is performed in MATLAB and a sensitivity analysis to assess the performance of each subsystem and the overall system is conducted. Results show that several operating conditions and state performances have the same end-results in terms of hydrogen production rate. Further, it is found that the LFR thermal efficiency of 61.67% and a solar fraction of 73.03% can be achieved. Also, maximum output power and efficiency of the hybrid converter as 19.85 kW and 44.76% is realized. As such, 93 units of EHC at a current density of 1 A/cm2 could be operated to produce hydrogen of 50 atm pressure at a rate of 2.17 kg/h.

Performance of Polymer Composite Constituted Cabinet Dryer Integrated within a Solar Flat Plate Collector

Generally, solar dryer cabinets are made up of sheet metals that are heavy, costly, tend to rust over time, and possess the high heat rate to the outer atmosphere. In order to overcome these drawbacks, this research urges to develop a natural fiber reinforced polymer-based cabinet dryer, specially designed and fabricated for the purpose of solar drying. Nylon is used as the matrix material and Prosopis juliflora in particulate form is used as the natural fiber reinforcement. The dryer cabinet was designed at industrial scale to dry 5 kg of ginger at a single setting. This work also studies the efficiency of the polymer composite cabinet integrated with a flat plate solar collector system that is coated with copper and black chrome attached to corrugated fins in between the absorber plate and storage medium. The FRP chamber was compartmented in its interior with aluminium perforated sheets and experimentation was performed to determine the efficiency of the composite cabinet based on reduction of heat loss from the system. The performance of the coating, storage medium materials, and overall storage efficiency were also studied. The FRP cabinet resulted in a moisture level less than 8.5% within 4–7 days. Exergy studies showed 75% efficiency and energy studies gave 25.5 kJ/kg peak readings of drying efficiency for a period ranging between 11 and 12 hours. This was a 75% increment in energy efficiency. Thermal degradation of the FRP material was found to be stable up to 300°C. The overall weight of the constructed polymer cabinet was 25% lesser than the conventional systems.

Towards Achieving Sustainable Development Goal-2030 Agenda-Thirteen: A Review of Technological Advances from the Built Environment Professionals

Natural resources are increasingly under pressures to cater for the growing human population and their corresponding, often conflicting needs. However, the need to conservatively utilize these resources without deteriorating the environment to the disadvantage of the future generations has prompted some actionable steps at the global level, the prominent of which is the promulgation of the United Nation’s Sustainable Development Goal 2030 (SDG-2030) Agenda, having seventeen (17) inter-related actionable areas of human endeavours (i.e., Agenda). Of particular interest within this context is the Agenda Thirteen (Agenda-13) which encompasses the need for urgent action to combat Climate Change and its impacts across various areas of human engagements. This is necessary as Climate Change impacts are characterized with anthropogenic carbon emissions resulting in global temperature rise, sea level rise, flooding, desertification, droughts, and other related disasters. Within the precinct of Built Environment, it is established that building construction and operation alone account for about 40% of the global emissions. This calls for concerns and requires urgent collaborative actions to curtail the trend. This submission, which is review based therefore, highlights various joint efforts particularly, integration of technological advancements by the relevant building professionals, towards attaining the goal of Agenda-13. This is with a view to limiting climate change enablers for reduced environmental impacts. These collaborative efforts are categorized into pre-construction and post-construction activities from the relevant professionals in the built environment. While the former includes Indoor Thermal Comfort Simulation, Integration of Daylighting Technologies, and adoption of Computational Fluid Dynamics integrated architectural design process, the latter consists of design of Double Skin Facades, development of Building Integrated Photovoltaics façade, integration of Evacuated Tube Solar Air Collector System, adoption of Phase Change Material on Building façade, and implementation of Life Cycle Energy Analysis Policy, among others. These endeavours aim at reducing carbon emissions at the building micro level for overall clean, safe and sustainable global environment.

Techno‐economic assessment of evacuated flat‐plate solar collector system for industrial process heat

AbstractIn the industrial sector, hot water applications constitute a significant share of final energy consumption. This creates a wide demand‐supply energy gap that must be bridged by integrating renewable sources with conventional fuels. This paper presents the performance analysis of a solar water heating system based on an evacuated flat‐plate collector (EFPC) with a surface area of 4 m2. A water–glycol mixture was used as the heat transfer fluid (HTF) with mass flow rates of 0.03, 0.0336, and 0.0504 kg/s under a vacuum pressure of –0.8 bar created inside the collector. A detailed numerical model was developed in MATLAB for the proposed EFPC system, followed by experimental validation. A maximum root mean square error of 2.81 for the absorber temperature and a percentage error of 6.62 was observed for the thermal efficiency in model validation. This substantiates the model's capability to predict actual system performance with reasonable accuracy. The maximum thermal efficiency of the EFPC is 78% with a maximum fluid outlet temperature of 98°C in June and 69°C in January. The maximum useful energy extracted is 1300 W in January. Additionally, the effect of design parameters on system performance such as mass flow rates, collector areas, tube spacing, and different HTF mixtures is simulated. Lastly, an economic analysis of the EFPC was conducted for hot water demand in a textile industry. The results revealed a payback period of 7.4 years, which highlights the feasibility of this system.

Experimental investigation of an asymmetric compound parabolic concentrator–based direct absorption solar collector using plasmonic nanofluids

Plasmonic nanofluid-based direct absorption solar collector (DASC) systems have shown a better perspective over surface-based solar thermalcollectors. These nanofluids demonstrated high thermal performance in photo-thermal conversion efficiency even at minute concentration compared to other testednanofluids. However, very few studies have been reported so farwith real-time outdoor experiments to show the opportunities and challenges in the practical applications of concentrating DASC systems. For the work presented here, an asymmetric compound parabolic concentrator (ACPC)-based DASC system has been designed, fabricated, and tested using mono-spherical gold and silver nanoparticle-based plasmonicnanofluids over several clear sky days at Jalandhar city (31.32° N, 75.57° E), India. The optical and morphological properties of synthesized nanoparticles were studied using UV-Vis spectrophotometry and High-resolution transmission electron microscopy (HR-TEM). Photo-thermal conversion tests were conducted using different working fluids and compared with a flat DASC system under similar operating conditions. The experimental results revealed that ACPC-based DASC system reached a maximum thermal efficiency of around 70% using plasmonic nanofluids which was approximately 28% higher than a flat DASC system with water as the working fluid. The stability analysis showed that plasmonic nanofluids are capable of retaining their optical properties even after several hours of sun exposure. The present study highlights the use of plasmonic nanostructures for achieving high photo-thermal conversion efficiency in concentrating DASC systems.

Enhancing solar stirling engine performance through the use of innovative heat transfer fin shapes

One of the challenges in designing and optimizing solar energy systems is achieving maximum power and efficiency at the lowest cost. This study focuses on using heat transfer fins to enhance energy absorption in the heater section of a solar Stirling engine. To begin, we model a parabolic solar collector system, considering factors that influence the amount of heat transfer to the heater section of the Stirling engine. Next, we model the Stirling engine using the PSVL model, which accounts for factors such as gas leakage, the temperature distribution in heat exchangers, longitudinal heat loss, polytropic heat transfer in cylinders, and other effects. In this paper, we also propose modifications to the basic model and introduce heat transfer fins made of FGM, with unique geometry and variable thickness, on the heater section of the solar Stirling engine to increase the heat received by the working fluid. We perform a thermal analysis of the fins to evaluate their impact on the heat the Stirling engine receives, including the effects of convection and radiation on the environment. We find that using these new fins in the heater section of the Stirling engine significantly increases the power and efficiency of the system.

Experimental validation of a numerical model for a sand-based seasonal thermal energy storage

A research facility with solar thermal collector system and a water-saturated, sand-based seasonal thermal energy storage (SSTES) is used to provide space heating and domestic hot water heating to homes in cold climates. A 3D finite difference model of the heat transfer in and around the SSTES is presented and validated with measured data. The SSTES has lost moisture over time, making its thermal properties difficult to estimate. Additionally, the experimental data shows the SSTES losing heat at twice the expected rate, potentially due to incorrect thermal parameters from the manufacturer and the SSTES insulation being damaged or degraded. The final numerical model was validated over a 163-day period where energy was being injected into and extracted from the SSTES. It was found that the seasonal performance of the SSTES could be predicted by a conduction-only heat transfer model, and this model is suitable to be included in BPS tools.

Numerical investigation on the thermal performance of parabolic trough solar collector with synthetic oil/Cu nanofluids

Nanofluids as the advanced heat transfer fluids, could be used in the parabolic trough solar collector system because of the enhanced thermal transport properties. In this paper, the effects of the same nanoparticles with two different base fluids on the thermal performance of the collector are numerically investigated by finite element method. Moreover, the effect of nanofluids on the cross-sectional temperature distribution of the absorber tube, which is well-known to affect the collector performance is here investigated. The numerical study is divided into two groups according to the value range of inlet velocity and inlet temperature, which represents different application scenarios of the collector. The results show that the synthetic oil/Cu nanofluids could increase the convective heat transfer coefficient under wide working conditions, but more pumping work is required because of the increase in pressure drop. The cross-sectional temperature difference of the absorber tube is greatly decreased with synthetic oil/Cu nanofluids. Furthermore, it’s found that Cu nanoparticles could trigger thermal and exergetic efficiency increment, especially at a low flow rate and high working temperature. The thermal performance improvement of these two thermal oils by Cu nanoparticles is different, and Syltherm 800 is more suitable for being the base fluid of nanofluid.

Particle-Size Effect of Nanoparticles on the Thermal Performance of Solar Flat Plate Technology

One of the cleanest and most efficient solar collector systems is the flat plate collector, which has applications in hot water production, drying, among others. Flat plate collectors have improved in terms of both their structural configurations and working fluids. Several studies have verified the comparatively higher efficiency of nanofluid-based flat plate collectors, relative to that of water and other thermal oils. Additionally, the influence of several nanofluid synthesis factors, such as volume fraction, pH, type of base fluid, hybridization, surfactants, and sonification, on the performance of these collectors has been highlighted in the literature. However, the effect of nanoparticle size on collector performance has received minimal research interest, despite its significant effect on both the cost of synthesis and the thermophysical properties of nanofluids. The uncertainties regarding the effect of nanoparticle size on thermal collectors have limited their practical applications. This study numerically investigates the effect of the nanoparticle size of silver (Ag) nanofluid with nanoparticle sizes between 20 nm and 100 nm on the performance of flat plate collectors. The effect of nanoparticle size on the mean fluid temperature resulted in a maximum temperature of 45.8 °C for the Ag-100 nm. An increase of 0.25 °C for the Ag-20 nm was recorded, relative to the Ag-100 nm. In addition, the Ag-100 nm was calculated to have resulted in the highest reduction in collector size (18.30%), relative to that of water.

Performance evaluation of a hybrid thermoelectric generator and flat plate solar collector system in a semi-arid climate

This study investigates the performance of a hybrid system that combined thermoelectric generators (TEG) with a solar flat plate collector system (SFPC) to turn more renewable energy into useable energy under normal operating and environmental conditions. A multi-month case study was first time conducted to explore the performance of SFPC with and without TEGs under the cold climatic conditions of Abha, Saudi Arabia. The result demonstrates that the heat losses from the rear surface of the SFPC's absorber plate were effectively utilized by TEGs, thereby decreasing overall heat losses and increasing the SFPC's overall thermal efficiency. Further, it was found that adding TEGs at the rear surface of SFPC's absorber plate improves thermal efficiency and exergy efficiency by 8.4% and 1.3%, respectively. The hybrid TEG-SPFC system can turn waste heat into useable electricity, with a peak power output of 2.2 W at midday. Maximum power was generated around midday, when the temperature differential between the upper and lower layers of TEGs was greatest. In addition, it was noticed that the thermal efficiency of the SFPC diminishes when the inlet water temperature rises. A hybrid TEG-SFPC system's exergy efficiency depends on ambient temperature variation and solar irradiance.

Influence of different thermal degradation processes on the optical property of Pyromark-2500

Concentrating solar power (CSP) is emerging as an increasingly important component of renewable energy. CSP systems are being widely adopted in the establishment of large-scale thermal power plants, with an increase in the number of successfully operating demonstration systems.Special coatings are generally used in various types of receivers for solar collector systems. Selective coatings are used for receivers intended to be operated at low or medium temperatures. Similar selective coatings are not currently available for application under high temperatures. In such cases, high-temperature absorbing coatings are generally used to improve the thermal efficiency of the receiver and protect their tubes from oxidation. It is worthwhile to observe the behaviour of such coatings when exposed to high fluxes for extended periods, in order to develop more efficient technologies.Currently, the essential properties for characterizing the paint are absorptivity, emissivity, and structural integrity of the coating (adhesion and cohesion). Good understanding of the behaviour of this paint under representative operating conditions would help to improve the design of the plant, maintain its performance and maintain the thermal efficiency of the receiver. The principal objective of this study was to provide extensive knowledge of the durability and variation of the optical properties of Pyromark when it is consolidated with improved methods. No degradation or loss of optical performance was observed at temperatures under 700 °C. The substrate affected the crystalline structure of an initial coating at high temperatures owing to the diffusion of metal ions. Concentrated solar radiation was the main factor that affected the integrity of the coating. At concentrations higher than 550× suns, a significant area of the irradiated samples was found to be uncoated. These results can be used to design more accurate latest generation receivers to improve the performance of this technology.

Performance Evaluation of an Evacuated Flat-Plate Collector System for Domestic Hot Water Applications

AbstractRapid population growth and increasing energy demand in developing countries are the key drivers behind rising concerns such as energy poverty and environmental degradation. Harnessing solar energy can help the developing countries inch closer to sustainable economic growth. This article presents the performance analysis of a solar water heating system based on an evacuated flat-plate collector (EFPC). EFPCs offer higher optical performance and lower thermal losses in comparison with conventional solar collectors. In this study, a multiparametric analysis provides the guidelines for the design and optimization of a novel low vacuum EFPC system under ambient conditions, for domestic hot water (DHW) applications. A small-scale solar thermal collector system based on a low vacuum (17.5–20 kPa) EFPC of a total area of 4.0 m2 is designed and installed. The system is coupled with a storage tank composed of the helical copper coil configuration inside the tank, which is used as a heat exchanger from a primary loop to a secondary loop. A series of real-time experiments are performed under ambient conditions from December to April. The thermal efficiency of the EFPCs reaches a maximum value of 73.2%, with the glycol–water mixture as a heat transfer fluid at an inlet temperature of 31.2 °C, when the ambient temperature is 15.3 °C, average irradiance is 679.2 Wm−2, and vacuum pressure is 20 kPa. For this duration, the exergy efficiency reaches a peak value of 16%. This EFPC system provides 100 liters of hot water at 57–69 °C per day for DHW consumption when the average ambient temperature is 24 °C. The overall results highlight the potential of EFPCs for hot water applications. Furthermore, an efficiently optimized EFPC system can also be used for space heating during the winter season.

An adaptive neuro-fuzzy approach to predict the thermal efficiency of differently configured solar flat plate water collector systems

An adaptive neuro-fuzzy approach to predict the thermal efficiency of differently configured solar flat plate water collector systems

Design of smart autonomous solar panel with cascaded SEPIC-boost converter for high voltage renewable applications

ABSTRACT The most admired alternative to conventional energy sources is solar energy. In north-eastern regions of India, where availability of sun is unpredictable but irradiance level is high, special observation is needed to upgrade the solar collection systems. The main objective of the research work is to develop a renewable system, which can extract maximum voltage using dual axis movable surface and design a cascaded converter, which can further increase the voltage while maintaining high efficiency. The output of the smart independent self-regulating solar panel hardware model proposed in this paper is fed into a DC–DC cascaded Boost-SEPIC system for renewable-based applications. The newly created renewable system is built to move the panel so that the most voltage is extracted. The DC–DC cascaded converter receives power from the solar panel’s output. To assess the system’s effectiveness and voltage gain, a thorough circuit analysis is carried out. The converter is tested using various duty cycles. With a 50% duty ratio and 90% efficiency, the suggested converter produces a 40 V DC output from a 20 V DC input voltage from a solar panel. Results from an experimental prototype are used to verify the converter’s viability.

Performance assessment of solar and desiccant aided building air-conditioning system

Indoor thermal comfort significantly influences people’s health, happiness and consequently the output at the workplace. Here, a systematic simulation study on a conventional vapor compression-based building cooling system integrated with desiccant assisted dedicated outdoor air system (DOAS) is performed using EnergyPlus software for warm and humid climate zones. Impact of using desiccant material in the DOAS, on the cooling load requirement of the building, coefficient of performance (COP), and energy consumption of the system is discussed. The building design is well-validated with the available guidelines. Desiccant assisted system supplies dehumidified air inside the building space which affects the evaporator performance. A flat plate solar collector system is used to supply the hot air to regenerate the desiccant material. Electric energy savings in desiccant assisted system can be achieved up to 5.5 %, whereas, the COP of the system is not found to be significantly affected even though thermal load demand reduces by nearly 13.5 % by the proposed modification.

Energy performance and economic assessments of a solar air collector and compression heat pump-integrated solar humidifier desalination system

This article presents the energy performance and economic assessments of a solar air collector (SAC) and compression heat pump (CHP)-integrated solar humidifier desalination system. The influences of solar heat flux, ambient wind speed and ambient temperature on the energy performance of the system are investigated. The quality of distilled water obtained from the system was assessed. The results showed that the proposed configuration has the maximum distillate output of 22.3 l per day in 14 hours of observations during the summer months. Moreover, the system delivers 100 l of hot water at 46 ± 2°C. The effectiveness of a solar humidifier was raised from 0.16 to 0.97. The coefficient of performance of the CHP was fluctuating between 2.40 and 2.77. The gain output ratio (GOR) was raised from 0.9 to 3.35 during the summer months. The proposed system has a payback duration (PBD) of 27.62 months for 14 hours of operation per day during 252 days in a year. The environmental impact assessments revealed that the system will release 32.35 tons of carbon dioxide emissions during 15 years life span. The quality of water obtained from the system was found to be good and suitable for drinking enriched with minerals.

3E analyses of a cogeneration system based on compressed air energy storage system, solar collector and organic Rankine cycle

Compressed air energy storage associated with renewable energy sources is a reliable method to solve energy shortage and achieve emission reduction. A novel cogeneration system which combines a compressed air storage system, an organic Rankine cycle system and a solar collector system is proposed. Parametric sensitivity analysis, exergy analysis, and economic analysis are performed. The results demonstrate that the proposed hybrid system with the air mass flow of 5400 kg/h has an output power of 389.19 kW and an output heat of 985.18 kW. The power efficiency, energy efficiency and exergy efficiency of the system are 24.63%, 86.96% and 67.57%, respectively. The total exergy destruction of the proposed system is 649.26 kW. The highest energy destruction, 199.43 kW, is provided by the solar collection system. The cost of total investments of the overall system is 6471.35 k$. The solar collector system and the turbine have the highest percentage of investment costs with 30.72% and 27.87% respectively. The economic analysis revealed that the simple and dynamic payback periods of the proposed hybrid system are 17.68 years and 11.56 years, respectively.

Analyze the Flow Behavior for MHD Power-Law Fluids

Objective: This study investigates the Numerical solution of laminar boundary layer flow of Magnetohydrodynamics (MHD) model for power-law fluid over a continuous moving surface in the presence of a transverse magnetic. Methods: The governing partial differential equation for the flow was transformed into non-linear ordinary differential equation using the Group theoretic method. Firstly, we convert this non-linear ordinary differential equation (ODE) into linear by using quasilinearization process. This linear ODE was solved numerically by applying the Spline collocation method suggested by Bickley. Findings: The solution for displacement profile and velocity profile were obtained as functions of the magnetic parameters. The effect of the magnetic parameters was discussed graphically. We used MATLAB software for finding the outcomes. Novelty: The main goal of this article is to analyze boundary layer flow of Magneto hydrodynamics (MHD) model for power-law fluid over a continuous moving surface in the presence of a transverse magnetic. The conservation equations of mass, momentum and energy are converted into ordinary differential equations along with boundary conditions by appropriate similarity transformations and solved by applying Spline Collocation Method. The convergence of solutions is important for providing the developing linear functions of solutions, which is a benefit of the Spline Collocation Method. These research findings are applicable, for example, in predicting skin friction and heat transfer rate over a stretching sheet, which has implications in technological and manufacturing industries such as polymer extrusion. Comparisons with previously published works are made, and the results show a high level of agreement. This type of research is applicable to work in fire dynamics in insulation, solar collection systems, recovery of petroleum products, etc. Keywords: Power-Law Fluids; Magnetic Field; Nonlinear Differential Equation; Quasilinearization; Bickley’s Method; Linear Equations

Development of an intelligent envelope system with energy recovery ventilation for passive dehumidification in summer and solar collection in winter

With the aim of establishing a zero-energy housing (ZEH), an intelligent envelope system composed of a passive dehumidification and solar collection system (PDSC system) based on thermodynamic energy theory and an energy recovery ventilation (ERV) unit has been developed, abbreviated as PSE (PDSC & ERV) system, which can be expected to control the indoor hygrothermal environment by using renewable energy further to reduce the heating and cooling demand for the HVAC system. In this study, the measurement experiments were conducted in a wooden house equipped with a PSE system, and the temperature and humidity distributions in the rooms were assessed using thermohygrometer sensors. The field comparison experiments for the three systems (exhaust-only ventilation system, ERV system, and PSE system) were performed separately under various meteorological conditions in summer and winter. The measurement results in summer showed that the PSE system has a significant dehumidification effect compared to the exhaust-only and ERV-only ventilation systems and could effectively reduce the latent heat load caused by ventilation. The measurement results in winter indicated that the PSE system has the effect of heat collection and humidity control as well as reducing the sensible heat load originating from ventilation.

Field study of system efficiency of detached house with solar energy system and fuel cell cogeneration system in Japan

In this study, the energy flow in detached houses in Sendai City in the Tohoku region of Japan where photovoltaic power generation system, solar thermal collection system, and fuel cell cogeneration system were installed was analyzed based on measured data. Hot water obtained by solar heat collected in the house is used to supply hot water to the kitchen throughout the year, to supply hot water to floor heating and to preheat the air supply of the HVAC system in winter, and to regenerate the desiccant wheel of the HVAC system in summer. A hybrid hot water supply system using city gas and a heat pump is used as an auxiliary heat source for a solar thermal system. As a result, the monthly energy self-sufficiency rate, energy efficiency and heat loss rate of the house for three years were calculated, and the necessity of the optimization of the operation method of the solar thermal system was found. In addition, daily analyses of solar thermal system in winter and summer suggested the importance of the operation corresponding to the weather.