Performance Of Flat Plate Solar Collector Research Articles

Passive techniques for the thermal performance enhancement of flat plate solar collector: A comprehensive review

One of the most abundantly available non-conventional energy sources is solar energy. The advantages of solar energy are that it is freely available, sustainable, non-exhaustible, pollution-free, etc. Many thermal energy technologies are frequently employed to utilize solar energy for different household, agricultural, residential, and industrial applications. A flat plate solar collector (FPSC) is one of the most popular devices for harvesting solar energy and transforming solar radiation into useful heat. The low thermal performance of FPSC is one of its major disadvantages. The performance of the FPSC can be enhanced using active, passive, and mixed methods. In this article, various thermal performance enhancement techniques of FPSC, including design and modification, use of inserts, selective coating, nanofluid, phase change material, mini/microchannels, and transparent insulation material, are discussed. The use of nanomaterial coatings can reduce the convection and radiation losses from the FPSC. High absorptivity black nickel nanoparticles make them excellent for selective coatings. The performance of FPSC with CuO/water nanofluid was more efficient than that of other metal oxides. The performance of a minichannel integrated FPSC is better than that of conventional type because of its direct contact with water, which enhances the heat transfer rate. The most recent technological development of enhanced FPSC discussed in this article will be very useful to the scientific community.

Green synthesized clove-treated carbon nanotubes/titanium dioxide hybrid nanofluids for enhancing flat-plate solar collector performance

Green synthesizing carbon-based hybrid nanofluids has the potential to drive innovation in both renewable energy technologies and nanomaterial applications. In this regard, the current experimental work focuses on enhancing the thermal performance of flat-plate solar collectors (FPSCs) using working fluids made of nanocomposite materials via an eco-friendly technique (clove). Conventional methods of synthesizing nanofluids frequently involve using hazardous chemicals, raising concerns about the environment and human health. This experimental work examined the energy efficiency, exergy efficiency, and hydrothermal performance of FPSC using clove-treated carbon nanotubes/titanium dioxide (CT-MWCNTs/TiO2) nanocomposites by the ratio of (60 % to 40 %) dispersed in distilled water (DW). The test conditions were in the following ranges: hybrid nanofluid in different weight concentrations (0.025, 0.05, 0.075, and 0.1 wt%), different flow rates (0.3, 0.6, 0.9, and 1.2 L/min), heat flux intensities (400, 600, 800, and 1000 W/m2) and inlet temperature (30, 35, 40, 45 °C). The experimental results revealed that, the maximum enhancement in the energy efficiency (20.6 %) and exergy efficiency (22.9 %) were achieved at 0.1 wt% and 1.2 L/min, relative to the base fluid. In addition, the solar collector size was reduced by 20.5 % due to using a hybrid nanofluid. To conclude, the hybrid nanofluid outperformed the mono nanofluids regarding overall thermal evaluations. The novel hybrid nanofluids generally showed promising results for managing and conserving energy applications.

Consideration of fouling by scaling in the sizing of flat plate solar collector networks

In this work, the effects of fouling on the performance of flat plate solar collector networks that operate with water as the thermal fluid are studied, and design considerations are put forward to be used in the sizing of these systems from the thermal and hydraulic points of view. The quantification of the effects produced by scaling is carried out through a mathematical model that predicts the deposition on the walls of the tubes. The model considers that CaCO3 is the only compound present in the fouling layer. Results indicate that for a volumetric flow rate of 3.78 l/min and assuming a CaCO3 concentration of 250 ppm, in a period of six months, the maximum outlet temperature that can be obtained in a day falls 1.5 °C and the pressure drop increases four times. It is shown that it is advisable to design a network of solar collectors considering scaling. The case study indicates that to supply a total flow rate of 48 l/min at a temperature of 70 °C, the design considering scaling requires 220 collectors and a volumetric flow rate of 4.8 l/min per line with a total annualized operating cost of $343,300 Mx.

A novel structure design and numerical analysis of porous media-assisted enhanced thermal performance of flat-plate solar collector

A novel structure design and numerical analysis of porous media-assisted enhanced thermal performance of flat-plate solar collector

Numerical investigation flat plate solar collector performance in Baghdad base on exergy analysis

Numerical investigation flat plate solar collector performance in Baghdad base on exergy analysis

CFD study of a dual-passage solar collector with longitudinal and transverse baffles for enhanced thermal performance

The focus of this research is to investigate the heat transfer performance of a solar flat plate collector by utilizing CFD simulation. To accomplish this, a 3-D model of the collector with an air inlet was created using ANSYS Workbench, and the grid was generated through ANSYS ICEM, ANSYS FLUENT, and ANSYS CFX were then used to obtain comprehensive results. The primary objective of this study is to enhance the efficiency of the solar collector by introducing two fluid-flow paths and comparing the results with those reported in existing literature. These findings will aid in the development of advanced solar collector designs and promote sustainable use of solar energy. Furthermore, the insights gained from this study may inspire further research in the renewable energy technology field. Overall, this re-search explores the potential of improving the performance of solar flat plate collectors and sheds light on how the use of CFD simulation can facilitate the development of innovative and sustainable energy solutions.

Performance Analysis of Flat Plate Base-Thermal Cell Absorber (FPBTCA): Low Thickness Design

Research to improve flat plate solar collector performance such as design and material used continuously developed. This paper's objective is to analyze the performance of the thermal cell absorber attached to a flat plate absorber collector (FPBTCA) through a low thickness design. It will produce a lightweight and portable collector application with efficient temperature conversion duration and has energy storage ability. Stainless steel and aluminum materials with different thicknesses use as thermal cell absorbers then aluminum materials use as a flat plate absorber base-collector. The experiment performs using a solar simulator with solar radiation of 700 W/m2. Referring to the results in term of heat storage (Qstorage), the heat transfer rate of the collector (Q ̇) and efficiency of the collector shows that stainless steel 1.0 mm with an aluminum base absorber (Case E) has a higher value which is 412 kJ, 18.21 kW, and 47.08 %, respectively. The higher total energy gain collected at the bottom plate as dummy load in the drying chamber (T1 and T2) is stainless steel 1.0 mm with an aluminum absorber base-collector (Case E) value of 2.85 kJ. Stainless steel 1.0 mm with an aluminum absorber base-collector (Case E) has the maximum value of energy gain at 300 seconds which is 116.08 J for the bottom plate (T1 and Ta). Flat plate base absorber thermal cell (FPBTCA CASE E) shows better performance in thermal storage than Flat Plate Solar Collector (FPSC).

Performance Augmentation of the Flat Plate Solar Thermal Collector: A Review

The need for hot water in residential buildings requires a significant energy potential. Therefore, an efficient water heating system is important to achieve the goal of saving high-grade energy. The most simple and cheapest solar water heater is a flat plate solar collector (FPSC), which can increase the thermal energy of fluid by absorbing solar radiation. The performance of FPSC is comparatively low due to the dilute nature of solar insolation. Therefore, advancement of FPSC is being undertaken to improve the performance and achieve size reduction. In past, several techniques have been exploited to improve the performance of FPSC, which are presented in the present paper. These techniques include surface modifications, use of nanofluids, solar selective coating, and applications of a mini/macro channel, heat pipe, and vacuum around absorber. Surface modification on the absorber/absorber tube techniques are exploited to transfer the maximum possible solar energy to working fluids by increasing the heat transfer rate. Insertion of wire mesh, coil, and twisted tapes in the flow has great potential to increase the Nusselt number by 460% at the expense of a large pressure drop. Selective coating of Cu0.44 Ti0.44 Mn0.84 helps to absorb up to 97.4% of the incident solar energy, which is more significant. Many nanofluids have been exploited as heat transfer fluids, as they not only increase the performance but also reduce the fluid inventory. So, these techniques play a very prominent role in the performance of FPSC, which are discussed in detail. Summaries of the results are presented and recommendations proposed.

Thermal performance analysis of large-scale flat plate solar collectors and regional applicability in China

The thermal performance of flat-plate solar collectors (FPSCs) depends not only on environmental and operational parameters but also on its dimensions. In this study, the thermal performance improvement mechanism of FPSCs is studied focusing on the impact of collector size. Numerical simulation models for both large-scale flat-plate solar collectors (LSFPSCs), and conventional FPSCs in parallel, are introduced. The relationship between thermal performance and collector dimensions is studied for the LSFPSCs. Furthermore, the effect of the environmental and operational parameters on the thermal performance of the two collector types is investigated. Moreover, the applicability of LSFPSCs in China is analyzed with respect to available operating times, useful energy, and heat loss. The results indicate that increasing the collector dimensions can improve the thermal performance of FPSCs effectively, and the LSFPSCs perform better than conventional FPSCs in parallel. Compared to the conventional FPSCs, the collector efficiency of the LSFPSCs is higher-especially for low solar irradiance, low ambient temperatures, and high mass-flow rates. In addition, the LSFPSCs excel in solar-energy rich areas, the available daily operating time in Lhasa is 9.6 h, which is the longest operating time among the studied cities, and the proportion of useful energy is about 55 %.

Angle of inclination and radiation intensity variation effects on the flat plate solar collector’s performance using graphene oxide (GO)-water nanofluid

Flat Plate Solar Collector is a special heat exchanger instrument that transforms solar radiation energy into heat energy. Various attempts have been completed to improve the flat plate solar collector’s performance. One of them is by developing advanced heat transfer fluid with better thermophysical properties than base fluid. Further, the flat plate solar collector’s inclination angle and radiation intensity were investigated to identify the most optimal solar radiation angle of incidence. This study discusses the use of a 0.006% graphene oxide-water nanoparticle toward the nanofluid’s thermophysical properties, sufficient radiation intensity of flat plate solar collector performance, as well as the inclination angle of flat plate solar collector toward the collector’s performance. The used radiation intensity variations were 415 W/m2, 515 W/m2 and 615 W/m2. Meanwhile, the radiation used in this study was from a sun simulator 750 W/m2. In each radiation intensity variation, the inclination angle test of 30°, 45°, and 60° for the flat plate solar collector were carried out. This study was expected to discover the best performance of graphene oxide-water nanofluid usage, collector’s inclination angle variation, and radiation intensity variation.

Thermal Performance of Flat Plate Solar Collectors for Humid and Unpredicted Weather using Air Properties and Energy Method

Devising technologies to make use of renewable energy such as solar energy is very innovative and progressive sincetapping energy from a free source is cost effective in the long-term and totally ecologically friendly. The main aim ofsolar drying of crops is to preserve them by removing the excess moisture that will cause their deterioration in orderto improve their shelf life. Solar drying though found to be a mature, cost-effective and an efficient method ofdrying especially crops, it has not been widely deployed for crop drying both at the commercial and industrial levelin Ghana. The purpose of this research is to produce a solar heat collector for space heating using cheap andavailable materials and also to demonstrate the importance of incorporating obstacle/fins on plates to improve theefficiency of solar collectors. This study investigates the effect of increased air contact area of various configurationon the efficiency of solar air heaters. Nine different absorber plates (with and without fins) were considered by thisresearch in an experimental study to select the best design that will be suitable for absorbing or providing a highfraction of heat for conditioning humid atmospheric air (lowest relative humidity of the collector air). The bestdesigns of this study had an efficiency between 58% to 72% and maximum absorber temperatures above 80oC,collector air temperature above 70oC and collector air relative humidity below 20% while the worst design had anefficiency between 35% and 50%, collector air temperature bellow 45oC and the lowest collector air relativehumidity of 26%. The findings of this research have revealed that increasing the contact area of the air current orcirculation and the shapes of the fins attached to flat absorber plates increase their air contact areas and affect thethermal efficiency of the solar collectors. Also, it has revealed that the arrangement of fins contributes positively tothe efficiency of solar collectors.
 Citation: Felix Uba, Eric Osei Essandoh, Gilbert Ayine Okolo, Charles Nunya Dzikunu. Thermal Performance of Flat PlateSolar Collectors for Humid and Unpredicted Weather using Air Properties and Energy Method, 2020; 5(4): 30-49.
 Received: September 17, 2020Accepted: December 31, 2020

Reducing thermal imbalances and flow nonuniformity in solar collectors through the selection of free flow area ratio

The effect of the riser to header diameter ratio and total cross-sectional area ratio on the flow distribution and thermal performance of flat-plate solar collectors is investigated. An analytical model based on the mass and momentum conservation equations is developed to determine the pressure drop and flow distribution in flat plate collectors. A numerical model is also developed to the assess the thermal effects of flow maldistribution. The accuracy of both models is verified against comparison with experimental measurements taken from the open literature. The use of the models is then extended to cover the flow distribution in solar collector networks. It is found that for laminar and turbulent conditions, cross-sectional area ratios and diameter ratios equal or lower than 0.75 and 0.25 respectively, minimize flow nonuniformity and reduce thermal imbalances. The results can be used for design purposes.

Thermal efficiency of a flat-plate solar collector filled with Pentaethylene Glycol-Treated Graphene Nanoplatelets: An experimental analysis

The effects of using aqueous nanofluids with the presence of Pentaethylene Glycol-Treated Graphene Nanoplatelets as the working fluids on the thermal performance of flat-plate solar collectors (FPSCs) were investigated experimentally. Water-based nanofluids were prepared with the concentrations of 0.025, 0.05, 0.075, and 0.1 wt%. Then the thermophysical properties were measured. Experimental setup and a MATLAB program were used to study the thermal performance of FPSCs-based nanofluids. The fluid inlet temperatures used in this study were 303, 313, and 323 K, and the flow rates were 0.00833, 0.01667, and 0.025 kg/s. Meanwhile, 500, 750 and 1000 W/m2 were set for the heat flux intensities. As the weight concentration was increased, thermal conductivity, dynamic viscosity, and density also improved, while specific heat decreased. The efficiency of FPSC increased as the flow rate and heat flux intensity were increased. However, the efficiency of FPSC decreased when the temperature of the fluid inlet was increased. Compared to water, the FPSC efficiency recorded an increase of up to 10.7%, 11.1%, and 13.3% for PEG-GNP nanofluids at different mass flow rates. Finally, the regression model was developed through MATLAB to predict the thermal efficiency coefficients of FPSC.

Numerical study of flat plate solar collector performance with square shape wicked evaporator

In this work, a system of a heat pipe is implemented to improve the performance of flat plate solar collector. The model is represented by square shape portion of the evaporator section of wicked heat pipe with a constant total length of 510 mm, and the evaporator section inclined by an angle of 30o. In this models the evaporator, adiabatic and condenser lengths are 140mm, 140mm, and 230mm respectively. The omitted energies from sunlight simulator are 200, 400, 600, 800 and 1000 W/m2 which is close to the normal solar energy in Iraq. The working fluid for all models is water with fill charge ratio of 240%. The efficiency of the solar collector is investigated with three values of condenser inlet water temperatures, namely (12, 16 and 20o C). The numerical result showed an optimum volume flow rate of cooling water in condenser at which the efficiency of collector is a maximum. This optimum agree well with the ASHRAE standard volume of flow rate for conventional tasting for flat plate solar collector. When the radiation incident increases the thermal resistance of wicked heat pipe is decreases, where the heat transfer from the evaporator to condenser increases. The numerical results showed the performance of solar collector with square shape evaporator greater than other types of evaporator as a ratio 15 %.

Experimental study of flat plate solar collector performance with twisted heat pipe

In this work, a system of heat pipe is implemented to improve the performance of flat plate solar collector. The experiment rig consists of sun light simulator, flat plate, heat pipe (wickless), heat exchanger, and measurement instruments. The model is represented by twisting portion of the evaporator section and also inclined by an angle of 30° with a constant total length of 1140 mm. In this model the evaporator, adiabatic and condenser lengths are 780mm, 140mm and 230mm respectively. The omitted energies from sun light simulator are 200, 400, 600, 800 and 1000 W/m2 which is close to the normal solar energy in Iraq. The working fluid for all models is water with fill charge ratio of 30% and the efficiency of the solar collector is investigated with three values of condenser inlet water temperatures, namely (12, 16 and 20° C). The experimental result showed an optimum volume flow rate of cooling water in condenser at which the efficiency of collector is a maximum. This optimum agree well with the ASHRA standard volume of flow rate for conventional tasting for flat plate solar collector. When the radiation incident increases the thermal resistance of thermosyphon is decreases, where the heat transfer from the evaporator to condenser increases. The experimental results showed the performance of solar collector with twisted evaporator greater than other types of evaporator as a ratio 13.5 %.

An experimental investigation on the performance of a flat-plate solar collector using eco-friendly treated graphene nanoplatelets–water nanofluids

The research on the use of nanofluids in thermal energy devices, like solar collectors, has secured a high place in the scientific community of recent years. In the present study, the effects of clove-treated graphene nanoplatelet nanofluids on the performance of flat-plate solar collector were investigated. For this, the graphene nanoplatelets and clove buds were covalently functionalized using the one-pot technique. Zeta potential test was conducted to check the stability of the graphene nanoplatelets–water nanofluid and found highly stable for 45 days. In the next step, three different mass concentrations 0.025 mass%, 0.075 mass% and 0.1 mass% were synthesized. The thermal performance of flat-plate solar collector at these three concentrations of the nanofluids of three different mass flow rates 0.0133, 0.0200 and 0.0260 kg s−1 m−2 was investigated in the next step. The results revealed that the thermal performance of solar collector enhances with the increase in mass concentration and mass flow rates and decreases with an increase in reduced temperature parameter. The highest thermal performance of a solar collector has reached 78% at mass concentration 0.1 mass% and flow rate 0.0260 kg s−1 m−2 which is 18.2% higher than water at the same flow rate conditions.

Flat plate solar collector performance using alumina nanofluids: Experimental characterization and efficiency tests.

Solar energy has become an important renewable energy source for reducing the use of fossil fuels and to mitigate global warming, for which solar collectors constitute a technology that is to be promoted. The use of nanofluids can increase the efficiency of solar into thermal energy conversion in solar collectors. Experimental values for the specific heat, thermal conductivity and viscosity of alumina/water nanofluids are needed to evaluate the influence of the solid content (from 0.25 to 5 v%) and the flow rate on the Reynolds, Nusselt and the heat transfer coefficient. In the laminar flow regime, thermal conductivity enhancement over specific heat decrement is key parameter, and a 2.34% increase in the heat transfer coefficient is theoretically obtained for 1 v% alumina nanofluid. To corroborate the results, experimental tests were run in a flat plate solar collector. A reduction in efficiency from 47% to 41.5% and a decrease in the heat removal factor were obtained using the nanofluid due to the formation of a nanoparticle deposition layer adding an addition thermal resistance to heat transfer. Nanofluids are recommended only if the nanoparticle concentration is high enough to enhance thermal conductivity, but no so high so as to avoid wall deposition.

Experimental and numerical study of the freezing process of flat-plate solar collector

Flat-plate solar collector is vulnerable to the freezing-damage. But the study of the antifreeze performance of the flat-plate solar collector is rarely reported in the published literatures. This paper presents a model with high precision to simulate the cooling and freezing process of flat-plate solar collector exposed to cold ambient air and conducts a prototype experiment to validate the model. Based on the validated model, factors influencing the antifreeze performance of flat-plate solar collector are investigated. Besides, the antifreeze effect of introducing TIM transparent honeycomb (TIM: transparent insulation materials) in the flat-plate collector is studied numerically. Results show that narrowing the pipe space, increasing the pipe diameter or header diameter and reducing the emissivity of absorber and glass-cover are the effective ways of enhancing the antifreeze performance of flat-plate collector. Meanwhile, employing TIM transparent honeycomb can significantly improve the antifreeze performance of flat-plate collector and can put off the completely frozen time of the collector by 2.5h.

Investigation of thermal behaviour, pressure drop, and pumping power in a Cu nanofluid-filled solar flat-plate collector

The evaluations of the performance of solar flat-plate collectors are reported in the literature. A computer program developed by MATLAB has been applied for modelling the performance of a solar collector under steady state laminar conditions. Results demonstrate that Cu-water nanofluid would be capable of boosting the thermal efficiency of the collector by 2.4% at 4% volume concentration in the case of using Cunanofluid instead of just water as the working fluid. It is noteworthy that, dispersing the nanoparticles into the water results in a higher pressure drop and, therefore, a higher power consumption for pumping the nanofluid within the collector. It has been estimated for the collector understudy, that the increase in the pressure drop and pumping power to be around 30%.

Predicting efficiency of flat-plate solar collector using a fuzzy inference system

With the increasing world population, industrialization and comfort need of humans, energy usage is growing considerably. Nowadays most of the energy needs are obtained from fossil stratum, and hydroelectric or nuclear power plants. However, usage of these fuels has two important problems: (1) These fuels may not exist in the near future and (2) Extensive use of these fuels causes serious environmental pollution. Alternatively, solar energy that is renewable and environmentally friendly energy can be utilized. In design of such renewable energy systems, efficiency is crucial including solar water heating systems. Experiments were conducted to evaluate a flat-plate solar collector performance of thermosiphon solar water heating system during the summer season in Nicosia, North Cyprus. A fuzzy inference system was developed to predict the efficiency of the solar collector. In our fuzzy inference system, we only utilize ambiance temperature, input and output temperature of the solar heating system. The predicted values were found to be in close agreement with the experimental counterparts with 0.9469,3.13, 6.96 coefficient of determination, root mean square error and average forecasting error respectively. It was noted that the proposed fuzzy inference system can provide high accuracy and reliability for predicting the performance of a solar collector. The advantages of this approach as compared to the testing methods are speed, simplicity, and the use of expert knowledge for prediction. Hence, the soft computing approach can be a potential tool for predicting efficiency of a flat-plate solar collector.