Performance Of Collector Research Articles

Experimental investigation of enhanced thermal performance of solar air collectors through optimized selection of manufacturing materials: Energy, exergy, economic, and environmental analysis

AbstractThe current study aims to experimentally investigate the thermal performance of three identical solar air collectors manufactured from three different metals: aluminum, zinc, and steel. The study conducted environmental and economic analyses of the three proposed solar air collectors over a month. The aluminum solar air collector demonstrated superior performance, achieving a maximum thermal efficiency of 24.46%, while the steel and zinc solar air collectors recorded thermal efficiencies of 21.57% and 18.16%, respectively. The exergy efficiency ranges for aluminum from 0.95% to 13.54%, zinc absorber plate exhibits from 0.63% to 11.89%, and steel from 0.6% to 9.98%. The aluminum solar air collector revealed high monthly cost savings of about $1429.6/month, followed by zinc ($1203.8) and steel ($963.4) solar air collectors. Environmental analysis to showed savings entering the atmosphere per month showed that the aluminum reduced about 19,795 kg CO2/month, Zinc solar air heat 16,668 kg CO2/month, and the steel solar air collector recorded 13,339 kg CO2/month. In this study, the absorber plate made of aluminum was the most efficient material, followed by zinc and steel. That confirms its suitability for designing efficient solar air heating systems in areas with high solar radiation intensity, such as Tunisia, and provides a clear direction for future research and development in manufacturing solar air collectors.

Investigation of the effect and mechanism on the flotation performance of alkylglycine-based collectors by acyl group

The structure difference of the flotation reagent has a significant influence on its flotation performance. In this work, sodium N-lauroyl glycinate (SNG) was synthesized by introducing an acyl group into sodium N-dodecylglycinate (SN), and was using the collector in the oxide ores flotation. Properties of these two collectors were compared, and the effects behavior and mechanism of introducing the acyl group on the flotation performance of alkylglycine-based collectors to the zinc oxide minerals were systematically investigated. Flotation results proved that the introduction of C = O group into SN barely affected the floatability of smithsonite, hemimorphite and calcite, while the floatability of quartz was greatly reduced. Contact angle tests, surface tension tests, and froth collapse measurements indicated that the introduction of the acyl group into SN could selectively weaken its ability to improve the hydrophobicity of mineral surfaces, reduce its surface tension, adsorption capacity and intensity on the mineral surface, and the froth stability, thereby enhancing its selectivity, consistent with the flotation results. Fourier transform infrared spectroscopy (FTIR) analyses and density functional theory (DFT) calculations revealed that the introduction of the acyl group could increase the cross-sectional area and reduce the charge of the SNG polar groups to selectively weaken the adsorption interaction, particularly by significantly reducing the electrostatic adsorption between SNS and quartz surfaces. These also confirm that SNG is a promising highly selective collector for the flotation separation of zinc oxide minerals.

Investigation of thermodynamics performance of solar dryer equipped with double pass flat, v-corrugated, and low-e coated collectors

In this study, a solar dryer incorporating a flat plate heat exchanger to recover heat from exhaust air was investigated to explore the usability of different types of collectors in the system. Their usability was further evaluated through economic and environmental analyses. Moreover, the thermodynamic performance of the solar dryers was evaluated under two weather conditions in Nepal. Apple drying experiments were conducted for 8 hours from 09:00 to 17:00 from February to April 2023 on solar dryers and with open sun drying (OSD) in Dhulikhel, Nepal. The results showed that the low emissivity (low-e) coated aluminum collector was more efficient in terms of collector efficiency and drying rate than collectors with flat or v-corrugated GI absorbers. The average collector efficiency and drying rate were found to be 89% and 107 g/(h×m2) using the low-e coated aluminum collectors, while the values were 50% and 84 g/(h×m2) for the GI sheet collector. The results indicated a slight improvement in the performance of v-corrugated collectors, with values of 53% and 89 g/(h×m2). The drying rate for OSD was found to be 78 g/(h×m2), which was lower than for the dryers with all collectors used in this study. In terms of economic analysis, the dryer equipped with the low-e coated collector was found to be superior, with a payback time of 1.61 years compared to the dryers with flat or v-corrugated GI collectors. Reducing the thermal losses due to radiation by using the low-e coated absorber was shown to be more important than increasing the absorber area using v-corrugated GI sheets.

Optimization of thermal performance in hybrid nanofluids for parabolic trough solar collectors using Adams–Bashforth–Moulton method

Solar energy is an environment-friendly renewable energy source that fulfills the energy consumption requirements of the world economy. Concentrated solar power is the most advanced technology that efficiently absorbs concentrated solar energy. This article investigates the solar energy storage and entropy generation in concentrated parabolic trough solar collectors for hybrid nanofluid flow due to a spinning tube inserted at the receiver's center. The effect of copper nanoparticles and multi-walled carbon nanotube mixture is studied using water-based fluid. Also, the influence of an external magnetic field is investigated with thermophoresis and Brownian motion of nanoparticles. The governing equations for the nanofluid flow are derived using the conservation principles of mass, momentum, energy, and concentration with boundary layer assumptions and no-slip boundary conditions. The governing equations are numerically solved using Adam Bashforth and Adam Moulten's fourth-order predictor-corrector numerical scheme along with the shooting approach. The numerical outcomes for the fluid velocity, temperature, Nusselt number, and entropy formation against various influential physical parameters have been discussed using graphs. It is observed that the augmenting Eckert number, thermophoretic diffusion parameter, and Brownian motion parameter escalates the thermal profiles. Also, an escalation of the radiation parameter and Lewis number enhances the Nusselt number. Thermal energy storage in solar collectors utilizing different terminologies is crucial for improving the efficiency and performance of solar thermal collectors.

Influence of submerged impingement jet designs on solar air collector performance

The present study experimentally investigates the solar air heater performance employing submerged impinging jets (SAHSIJ). The submerged jets produce high flow velocities, leading to significant turbulence aided by shear forces at the heated surface, resulting in increased and evenly distributed heat removal rates. The study explores the impact of geometric parameters viz jet spacing ratio (Sj/Dh) from 0.108 to 0.433, jet angles (α) from 75° to 90° jet diameter ratio (d/Dh) from 0.043 to 0.076, span-wise pitch ratio (Y/Dh) from 0.43 to 1.08 and stream wise pitch (X/Dh) from 0.43 to 1.73 on the Nusselt number and friction performance to enhance the overall efficacy of the system. To evaluate the effectiveness of the new SAHSIJ design in terms of thermal and thermo-hydraulic performance, the results are compared with those from a smooth duct solar air heater. The results show that the novel solar air heater with submerged pipe jet significantly outperforms the smooth duct solar air heater in terms of heat removal from the absorber plate. SAHSIJ achieved a thermal efficiency (ηth) of 75.3 % and a thermo-hydraulic efficiency (ηeff) of 69.2 %, with a thermo-hydraulic performance parameter (η) of 3.19.

Nanofluid effect on dual-flow parabolic trough collector performance accompanies with passive technique using experimental data

Purpose Using passive techniques like twisted tapes and corrugated surface is an efficient method of heat transfer improvement, since the referred manners break the boundary layer and improve the heat exchange. This paper aims to present an improved dual-flow parabolic trough collector (PTC). For this purpose, the effect of an absorber roof, a type of turbulator and a grooved absorber tube in the presence of nanofluid is investigated separately and simultaneously. Design/methodology/approach The FLUENT was used for solution of governing equation using control volume scheme. The control volume scheme has been used for solving the governing equations using the finite volume method. The standard k–e turbulence model has been chosen. Findings Fluid flow and heat transfer features, as friction factor, performance evaluation criteria (PEC) and Nusselt number have been calculated and analyzed. It is showed that absorber roof intensifies the heat transfer ratio in PTCs. Also, the combination of inserting the turbulator, outer corrugated and inner grooved absorber tube surface can enhance the PEC of PTCs considerably. Originality/value Results of the current study show that the PTC with two heat transfer fluids, outer and inner surface corrugated absorber tube, inserting the twisted tape and absorber roof have the maximum Nusselt number ratio equal to 5, and PEC higher than 2.5 between all proposed arrangements for investigated Reynolds numbers (from 10,000 to 20,000) and nanoparticles [Boehmite alumina (“λ-AlOOH)”] volume fractions (from 0.005 to 0.03). Maximum Nusselt number and PEC correspond to nanoparticle volume fraction and Reynolds number equal to 0.03 and 20,000, respectively. Besides, it was found that the performance evaluation criteria index values continuously grow by an intensification of nanoparticle volume concentrations.

Numerical Investigation of Solar Collector Performance with Encapsulated PCM: A Transient, 3D Approach

This study presents a comprehensive numerical investigation into the thermal performance of solar collectors integrated with encapsulated phase change materials (PCMs) using a transient three-dimensional (3D) approach. The performance of two distinct PCMs—paraffin wax and RT60—was evaluated under varying operational conditions, including seasonal variations, inlet pipe velocities, and inlet temperatures. The results indicate that paraffin wax exhibits a higher peak temperature, reaching approximately 360 K, compared to RT60’s peak of 345 K, making paraffin wax more effective for consistent thermal energy storage. Paraffin wax also maintained higher fluid fractions, with a maximum of 0.9 in summer, indicating superior heat absorption and retention capabilities. In contrast, RT60 demonstrated a quicker phase transition, fully liquefying at a lower fluid fraction, which is advantageous for rapid heat release. Seasonal variations significantly impacted system efficiency, with the highest efficiency observed in June at 365 K and the lowest in December at 340 K. The study also found that lower inlet velocities (e.g., 0.25 L/s) significantly improved heat retention, resulting in higher outlet temperatures, while increasing the inlet temperature from 290 K to 310 K led to a marked increase in outlet temperatures throughout the day. These findings underscore the importance of optimizing PCM selection, inlet velocity, and temperature in enhancing the performance of solar thermal systems, offering quantitative insights that contribute to the development of more efficient and reliable renewable energy solutions.

Study on the performance of flat-plate collectors with a bottom-mounted non-tracking broken line type reflector

The current flat-plate collectors commonly utilize non-tracking reflectors, primarily in a flat configuration, which is not optimal because it has a large reflection loss at varying solar altitude angles. Broken line type structures have been proven to exhibit better light concentration effects. However, existing research has focused solely on broken line type reflector installed at the top of the collector, leaving a gap in the study of broken line type reflector installed at the bottom. This paper investigates this aspect. Mathematical models for the performance analysis of collectors with/without bottom-mounted reflectors are established. The accuracy of the models is verified using the light tracing software, TracePro. The study includes the simulation analyses of the collector's performance and reflection losses under different conditions. The results indicate that the plate type reflector and broken line type reflector increase the heat collection by 27.92 % and 34.4 %, respectively. So the reflector can make the collector effectively operate in a wider range of ambient temperatures and radiation intensity. Increasing the horizontal length of the collector or adopting a series arrangement can effectively reduce reflection losses. This study provides theoretical guidance for the optimization design of flat-plate collectors with bottom-mounted broken line type reflectors.

Performance Improvement of an Integrated Collector Storage Solar Water Heater by Using an Additional Glass Cover: A Numerical Study

This paper describes the analysis of a solar storage water heating system, emphasizing its cost-effectiveness and integrated design. The study employs numerical analysis to assess and optimize the performance of a rectangular solar collector with an added glass cover and an internal horizontal barrier. Using COMSOL software, a three-dimensional modeling study was conducted in the Kufa-Najaf climate on May 9th. The analysis focused on fundamental convection equations governing mass, momentum, and energy conservation. Temperature and velocity distributions were obtained at 13:30 PM, revealing a peak storage water temperature of 56.3 °C. The additional glass cover-barrier storage collector, set at a 60° angle, exhibited the highest stored energy at 2065.6 W, surpassing the conventional storage collector at 1007.06 W. Furthermore, the model demonstrated an increased instantaneous efficiency of 58.3%, compared to 28.4% for the conventional collector. The simulation results align well with previous findings, showing a maximum mean absolute percent error (MAE) of 4.5%.

Interpretable machine learning study of a collector based on combined twisted-tape and wavy-tape inserts

Nowadays, the efficiency of air collectors for solar thermal applications is still low, and many researchers tend to use machine learning to predict and model the performance of thermal systems, but most of the existing machine learning methods are uninterpretable, which poses a challenge for machine learning applications. In this paper, a new collector insert with enhanced heat transfer in the form of a combination of wave and helical twisted bands is firstly designed for performance test experiments using solar air collectors. Then, based on the test data, three mutually interpretable machine learning methods, PDP, ALE, and SHAP, are explored for predictive studies of collector performance. The results show that the average efficiency of the collector with inserted structure increases by 19.71 %, 12.25 %, and 17.53 % at inlet flow rates of 2.1 m/s, 3.3 m/s, and 4.5 m/s, respectively. The highest collector efficiency was achieved with a wave plate length of 360 mm, a helical twist ratio of 5.14, and an inlet flow rate of 4.5 m/s. Understanding how much the input affects the output through the interpretability of SHAP proves the value of interpretable machine learning, which is useful in guiding the modification of the collector structure.

Experimental study on thermal performance of reverse flow solar collector for dual heating applications

AbstractThe present study investigated the performance of dual function reverse flow solar collector (RFSC). The impact of the mass flow rate of air and water on outlet temperature, thermal performance, and overall performance of dual‐function solar air heater (SAH) has also been investigated. An experimental investigation of three different working models namely, Model‐A: SAH, Model‐B: solar water heater (SWH), and Model‐C: integrated solar air‐water heater (SAWH) for dual heating applications was performed to analyze the actual performance of these models. The investigation of the impact of time intervals on the water inlet and outlet temperatures at various mass flow rates of water is conducted to analyze the time‐varying efficiency of SWH systems. Furthermore, the effect of solar intensity on the performance of the dual‐function heating system has also been explained. The result reveals that the maximum thermal efficiency of Models: A and B can be achieved at about 78.8% and 67.9%, at a mass flow rate of 0.0644 and 0.10 kg/s, respectively, according to the experimental findings. The maximum temperature rise of air and water reaches about 52.4 and 55.58°C for Models A and B, respectively. The total efficiency of Model C reaches 81.69%, exceeding that obtained in Models A and B individually. The efficiency, outlet temperature of the fluid, and heat transfer effectiveness of the system strongly depend on the mass flow rate. The increase in heat removal factor is negligible for a higher flow rate (more than 0.10 kg/s).

Ultra-low temperature heating system based on dual-source solar assisted heat pump using compound parabolic concentrator-capillary tube solar collector

The fifth-generation heating – ultra-low temperature heating benefits to reduce electricity consumption and achieve the net zero goal. The dual-source solar assisted heat pump based heating system has been demonstrated to be an attractive green heating technology for the domestic sector. However, the slower response speed of the low temperature heating to the variation of heating load in responding to the variations of weather conditions limits its thermal comfort performance. The enhancement in solar collector performance brings valuable improvements in response speed of the heating system. In the present work, a heating system based on solar assisted air source heat pump using a compound parabolic concentrator-capillary tube solar collector (CPC-CSC) is investigated with the set heating temperatures of 40, 45, 50, and 55 °C. This heating system works for both space heating and hot water under the weather conditions in London. The results suggest that using a concentrated solar collector improves the response speed of the heating system at low set heating temperatures. For such a heating system, the ultra-low heating temperature increases the application of renewable energy and passive heating (by 6.4%). Compared with the dual-source indirect expansion solar assisted heat pump using flat plate collector, the heating system using CPC-CSC can reduce TEWI by 4.6% with a slightly longer (1.9%) payback period. As the set heating temperature decreases from 55 to 40 °C, the seasonal and yearly system seasonal performance factors significantly increase by 17.1% and 20.5%, respectively.

Thermodynamics-Informed Neural Networks for the Design of Solar Collectors: An Application on Water Heating in the Highland Areas of the Andes

This study addresses the challenge of optimizing flat-plate solar collector design, traditionally reliant on trial-and-error and simplified engineering design methods. We propose using physics-informed neural networks (PINNs) to predict optimal design conditions in a range of data that not only characterized the highlands of Ecuador but also similar geographical locations. The model integrates three interconnected neural networks to predict global collector efficiency by considering atmospheric, geometric, and physical variables, including overall loss coefficient, efficiency factors, outlet fluid temperature, and useful heat gain. The PINNs model surpasses traditional simplified thermodynamic equations employed in engineering design by effectively integrating thermodynamic principles with data-driven insights, offering more accurate modeling of nonlinear phenomena. This approach enhances the precision of solar collector performance predictions, making it particularly valuable for optimizing designs in Ecuador’s highlands and similar regions with unique climatic conditions. The ANN predicted a collector overall loss coefficient of 5.199 W/(m2·K), closely matching the thermodynamic model’s 5.189 W/(m2·K), with similar accuracy in collector useful energy gain (722.85 W) and global collector efficiency (33.68%). Although the PINNs model showed minor discrepancies in certain parameters, it outperformed traditional methods in capturing the complex, nonlinear behavior of the data set, especially in predicting outlet fluid temperature (55.05 °C vs. 67.22 °C).

High thermohydraulic performance of solar air collector utilizing high turbulence deflectors and porous media

In this research investigation, high thermohydraulic performance of a solar air heater is obtained utilizing a deflector attached to the back plate and inserted porous media in the channel that generators high turbulence. The optimum values of the geometrical parameters such as fin pitch 0.02m≤P≤0.04m,fin height 0.005m≤H≤0.02m and channel porosity 80%≤ϕ≤100% and flow parameter, i.e., Reynolds number 2000≤Re≤11000 are obtained using numerical investigation. The obtained results present impressive facts through contours of velocity and temperature, and ensured the manifestation of high heat transfer to the flowing air in the investigated design. It is revealed that due to the use of deflectors, the bulk fluid got deflected towards the hot absorber plate, while the both deflector plus porous media in the channel causes high turbulence and consequently high thermal and thermohydraulic (THPP) performance is achieved. Numerical results presented interesting results of occurring the wavy flow inside the design of porous solar air heater with deflector. The THPP of the deflector plus porous media design is obtainted as 15, while it is about 1.2 for the design consisting of only deflectors. The optimum value of the combined deflector plus porous media design is obtained as P = 0.04 m, H = 0.02 m, ϕ=95% and Re = 8000, while it is P = 0.06 m, H = 0.02 m and Re = 8000 for the only simple deflector design.

Performance investigation on PVT collector with cerium oxide nano fluids

The constant temperature rise on the solar panel surface causes a deterioration of electrical power generation. This article is provided with the performance of photovoltaic thermal (PVT) collector through cerium oxide with water as a base fluid. A small percentage of incoming radiation is transformed into electricity and rest of them is wasted as hot energy, the panel surface temperature will confine the performance of PV module. The research's objectives were to develop and construct a photovoltaic/thermal collector and evaluate its thermal and electrical energy as an output. The experimental investigation of PVT collector with two different concentration of cerium oxide 0.5 and 1.0 LPM (litres per minute). As per the investigations on the PVT collector results were obtained as electrical performance of collector was attained about 18.56 %, 19.12 % for the flow rate of 0.5 and 1.0 LPM. Similarly, thermal performance was achieved 48.38 %, 54.03 % for the flow rate of 0.5 and 1.0 LPM. Thermal conductivity of cerium oxide nano fluid was much better than the air and water. It was observed that employing a nano fluid to the receiver might increase the efficiency around 5–10 %, compared to utilising water as a base fluid, water can only generate 3–7 %. As a cooling medium, air has a relatively low production capacity between 2 and 3 %.

Analysis of Implication of Phase Change Material Enclosed Design on Thermal Performance of Solar Collector

Abstract The energy, which is converted from the sun rays, was called solar energy. This is very essential renewable energy converting methods that had a higher influence for water distilling system. Here, the implication of the Phase Change Materials (PCM) in that exit was analyzed. This energy from the sun is trapped in paraffin wax for the storing system whiles the greater radioactive effect. This trapped heat power than utilized for increase the fluid temperature during the lesser radioactive times. Here, the Implication of the heat storing units on the exit temperature was analyzed. Furthermore, Thermal solar collector was analyzed for the following years 2021 and 2022. The Concentric PC is placed over the top of the collector of the solar rays. And then, a paraffin wax layer was placed under the solar absorber plate like the back-up to store the LH Energy. The uniform rate of flow was produced a greater exit temperature of water the two years. The efficiency rate increased 11–14% and the collected energy gain rate enhanced 18–19%. The peak water temperature was 61°C & 60°C for the 2 consecutive years for Paraffin wax integrated solar collecting unit. At the same time the efficiency of heat energy is peak at 49% in January 2022. The solar collector efficiency primarily relies on the design and construction of collector itself.

Innovative binary nanofluid approach with copper (Cu - EO) and Magnetite ([formula omitted] - EO) for enhanced thermal performance

In this study, we present an innovative and detailed analysis of the motion of a binary nanofluid, specifically copper (Cu - EO) and Magnetite (Fe3O4 - EO), in a porous medium under solar radiation. Our research is driven by the potential to significantly enhance the thermal performance of a Parabolic Trough Solar Collector (PTSC) using a binary nanofluid. The boundary conditions, partial differential restrictions, and the governing PDEs are transformed into the ODEs system with appropriate similarity transformations. The finite element method (FEM) and semi-analytical technique memad Akbari-Ganji's Method (AGM) are used to solve the approximate solutions of ODEs. The findings of evaluating Copper (Cu - EO) and Magnetite (Fe3O4 - EO) were the two different nanofluids based on engine oil that were presented. Furthermore, the model's overall entropy variations are enhanced using Reynolds. Moreover, our study contributes to understanding fluidity and viscosity alterations in such systems. We use the Brinkman number to observe these alterations. We reveal that the thermal efficiency of (Cu - EO) is lower than (Fe3O4 - EO) by a range of 0.005–0.6. This indicates a substantial enhancement in the thermal performance of the PTSC.

Effect of absorber shape on energy, exergy efficiency and enviro‐economic analysis of solar air collector: An experimental study

AbstractThe efficiency of solar air collectors, which are intended to convert solar energy into thermal energy, is the subject of numerous studies that aim to assess and improve it. Solutions for sustainable energy heavily rely on these systems. Making the right choice regarding the best method for absorbing solar radiation and reducing heat losses is what will ultimately lead to their improved performance. In this work, wavy and corrugated absorbers were suggested inside a solar air collector. The aim of this article is to study experimentally the thermal performance of the solar air collector when using wavy shape of absorber and corrugated shape of absorber instead of the flat shape of absorber under the same weather conditions of Sfax region central‐eastern of Tunisia. The suggested shapes of absorber augmented sun exposure and heating area. The results obtained from this experimental study show that switching from a flat plate absorber to both wavy and corrugated absorbers resulting significant performance gains. The absorber with waves showed a significant improvement in daily thermal efficiency of 22.89%, and the absorber with corrugations showed an even greater improvement of 40.56%. Comparable patterns were noted in daily exergy efficiency, where the corrugated absorber demonstrated an astounding 44.83% increase and the wavy absorber provided a 23.24% improvement. Notably, when total cost savings and monthly CO2 reduction were taken into account, the corrugated absorber turned out to be the best option. These findings highlight the importance of absorber form in optimizing thermal and energy efficiency, which may have positive effects on the economy and environment.

Investigation the Performance of an Evacuated Tube Solar Collector Filled with MWCNT/ Water Nanofluid Under the Climate Conditions of Al-Hilla (Iraq)

The main obstacles to securing the future of humanity are the rising energy demand and the constrained supply of conventional energy sources. In order to guarantee the sustainability of energy in this world for the present and the future, solar energy is a desirable source of energy. Solar thermal collectors with evacuated tubes are primarily employed in domestic settings. Even in low-temperature applications, replacing the working fluid with nanofluid can improve heat transfer. The effect of Multi-Walled Carbon Nanotubes (MWCNT) and water nanofluid as working fluids in evacuated tube solar collectors(ETSC) is used to investigate the collector's thermal performance experimentally. Three different volume fraction of (MWCNT) nanoparticles of (0.01%, 0.03% and 0.05%) were examined at various volume flow rates ranging from (1 to 3 L/min). Experiments were performed in Al –Hilla, Iraq. The results show an enhancement in the efficiency with increase in the volume fraction of(MWCNT)nanoparticles and volume flow rate (i.e. concentration (0.05%) and volume flow rate (3L/min). The temperature difference of the fluid at concentration (0.05%) and volume flow rate (1L/min) increased up to (86.84 %) with adding (MWCNT) nanoparticles compared with the water. The results showed, maximum efficiency enhancement of the collector at concentration (0.05%) and volume flow rate (3L/min) about (69.63%) compared with water.

Thermo-hydraulic performance of a parabolic trough solar collector filled with three different waste materials

This study presents the experimental investigation of the performance enhancement of a parabolic trough solar collcector (PTC) utilising air as the working fluid and various metallic waste materials as absorber fillers. The experiments have been carried out according to the ISO 9806:2017 norm under clear sky conditions for several days. The application of wire mesh, metal chips and bearing balls as the absorber filling has led to the increase in the performance of PTC and higher outlet temperatures compared to the smooth pipe as a receiver: 282 % (117.6 °C), 250 % (103.1 °C) and 335 % (128.3 °C) respectively. A decrease in PTC performance due to pressure drop was observed. The maximum drop for wire mesh, metal chips and bearing balls filling was: 9.7 %, 5.7 % and 5.7 % respectively. It has been shown that the use of metallic waste materials can significantly improve the thermal performance of PTC, but the rapidly increasing hydraulic resistance may limit their application for high flow rates.