Abstract

This study presents a detailed experimental and numerical analysis of a solar parabolic trough collector (PTC) designed and fabricated based on the ACUREX solar field geometry. Its thermal performance was evaluated under real operating conditions. The experimental setup employed Therminol VP-1 as the heat transfer fluid (HTF) at a steady flow rate of 12 L/min to validate a one-dimensional (1D) two-pipe mathematical model. The model incorporated energy balance equations for the absorber and glass envelopes, integrating principles of conduction, convection and radiation. The results indicated a maximum variation of 0.79% only between measured and predicted outlet temperatures, confirming the high predictive accuracy of the developed model. The collector exhibited stable operation over the medium-temperature range (100°C–320°C), with peak outlet temperatures occurring between 12:00 PM and 2:00 PM, corresponding to maximum direct normal irradiation (DNI). Statistical validation yielded a root mean square error (RMSE) of 1.39 K and a mean absolute error (MAE) of 1.22 K, both of which fell within the combined experimental uncertainty of ±1.4 K. Moreover, convective losses accounted for approximately 58% of total heat losses, followed by radiative (22%) and conductive losses (1%). These findings assert that the proposed 1D model accurately represents the collector’s thermo–hydraulic behaviour while offering a computationally efficient alternative to complex computational fluid dynamics (CFD)–based approaches. These observations highlight the importance of optical–thermal coupling including incident angle modifier (IAM), proper system insulation and optimal mass flow management for improving energy conversion efficiency in solar PTC systems.

Keywords

Parabolic trough collector (PTC), Therminol VP-1, One-dimensional thermal modelling, Thermo–hydraulic performance, Solar thermal energy systems.

Cite this article

Beldar K, Kale R. Experimental validation of a two-pipe one-dimensional optical–thermal model for an Acurex-based parabolic trough collector using Therminol VP-1. International Journal of Advanced Technology and Engineering Exploration. 2026;13(135):189-208. DOI : 10.19101/IJATEE.2025.121220506

References

[1] Silva OK, Kumaragamage CG, Perera MV, Arachchige US. Solar energy technologies: a complete review of the solar system technologies. Journal of Research Technology and Engineering. 2024; 5(1):84-111.

[2] Omeiza LA, Abid M, Dhanasekaran A, Subramanian Y, Raj V, Kozak K, et al. Application of solar thermal collectors for energy consumption in public buildings–an updated technical review. Journal of Engineering Research. 2024; 12(4):994-1010.

[3] Ahmad A, Prakash O, Kausher R, Kumar G, Pandey S, Hasnain SM. Parabolic trough solar collectors: a sustainable and efficient energy source. Materials Science for Energy Technologies. 2024; 7:99-106.

[4] Maxwell JB, D’antonio M, Henkel EE, Rigos B, May K, Creamer K. Solar thermal system for industrial dehumidification and steam generation. ACEEE Summer Study on Energy Efficiency in Industry. 2009; 1(3):80-90.

[5] Al HS. The future of solar power: chapter 8. solar thermal energy storage: materials, heat transfer analysis, and applications. In the future of solar power 2024 (pp. 217-68). Nova Science Publishers, Inc.

[6] Singh RK, Chandra P. Parabolic trough solar collector: a review on geometrical interpretation, mathematical model, and thermal performance augmentation. Engineering Research Express. 2023; 5(1):012003.

[7] Hebbal U, Soragaon B, Rathnakar G, Das AM, Thippeswamy LR, Nagabhushana N, et al. Principal difficulties with parabolic trough collector systems and performance-boosting strategies: a comprehensive review. International Journal of Thermofluids. 2025; 25:1-16.

[8] Egerer U, Dana S, Jager D, Xia G, Stanislawski BJ, Yellapantula S. Wind and structural loads data measured on parabolic trough solar collectors at an operational power plant. Scientific Data. 2024; 11(1):1-15.

[9] Pun AK, Suri AR, Rana R, Thapa S, Kumar K, Singh S. A review study on the advancement in structural design of solar parabolic trough collector. In AIP conference proceedings 2023 (p. 020008). AIP Publishing LLC.

[10] Chavarría-domínguez B, De LSE, Velázquez-limón N, Ponce-silva M, Aguilar-jiménez JA, Chavarría-domínguez F. A review of the modeling of parabolic trough solar collectors coupled to solar receivers with photovoltaic/thermal generation. Energies. 2024; 17(7):1-32.

[11] Chaanaoui M, Vaudreuil S, Eddouibi J, Ladouy S, Abderafi S, Bounahmidi T. A detailed 1D model of a parabolic trough solar receiver with a double-validation approach. Energy. 2024; 294:130857.

[12] Messaouda A, Hamdi M, Hazami M, Guizani A. Thermal assessment of cylindrical parabolic integrated collector storage using input-output and dynamic system testing procedures: experimental and numerical study. Energy Exploration & Exploitation. 2024; 42(5):1829-52.

[13] Donga RK, Kumar S, Velidi G. Numerical investigation of performance and exergy analysis in parabolic trough solar collectors. Scientific Reports. 2024; 14(1):1-16.

[14] Phu NM, Tu NT. One-dimensional modeling of triple-pass concentric tube heat exchanger in the parabolic trough solar air collector. In Heat Exchangers 2021. IntechOpen.

[15] Shokrnia M, Cagnoli M, Grena R, D’angelo A, Lanchi M, Zanino R. Comparative techno-economic analysis of parabolic trough and linear fresnel collectors with evacuated and non-evacuated receiver tubes in different geographical regions. Processes. 2024; 12(11):1-26.

[16] Bouarfa I, El YM, El H H, Boujoudar M, Jamil A, Bennouna EG. Developing optical and thermal models with experimental validation of parabolic trough collector for Moroccan industrial heat applications. Solar Energy Materials and Solar Cells. 2024; 266:112676.

[17] Ebolese A, Marano D, Copeta C, Bruno A, Sabatelli V. Numerical modeling and experimental validation of heat transfer characteristics in small PTCs with nonevacuated receivers. In solar 2023 (pp. 544-65). MDPI.

[18] Ktistis PK, Agathokleous RA, Kalogirou SA. Experimental performance of a parabolic trough collector system for an industrial process heat application. Energy. 2021; 215:119288.

[19] Akhatov JS, Akhmadov KS, Juraboyev NI. Thermal performance enhancement in the receiver part of solar parabolic trough collectors. UNEC Journal of Engineering and Applied Sciences. 2023; 3(2):5-13.

[20] El KA, Gallego FO. Modeling and numerical simulation of a parabolic trough collector using an HTF with temperature dependent physical properties. Mathematics and Computers in Simulation. 2022; 192:430-51.

[21] Goel A, Mahadeva R, Manik G. Analysis and optimization of parabolic trough solar collector to improve its optical performance. Journal of Solar Energy Engineering. 2023; 145(3):031009.

[22] Kasem MA. Detailed performance analysis of parabolic trough collectors including geometric effect. Journal of Mechanical Engineering and Sciences. 2023: 9552-63.

[23] Sebbar EH, Labtira A, Hmimou A, El RT. Modeling and numerical simulation of a parabolic trough solar collector connected to a solar tracker. Journal of Thermal Science and Engineering Applications. 2024; 16(10):101009.

[24] Ghaedi A, Sedaghati R, Mahmoudian M. Reliability evaluation of solar power plants equipped with parabolic trough reflectors. Journal of Solar Energy Research. 2023; 8(3):1635-50.

[25] Bakhti H, Gasser I, Schuster S, Parfenov E. Modelling, simulation and optimisation of parabolic trough power plants. European Journal of Applied Mathematics. 2023; 34(3):592-615.

[26] Asiri S. A time-delayed model and estimation in parabolic-trough solar collectors. Contemporary Mathematics. 2024: 6082-92.

[27] Carvalho RM, Ismail KA. Modeling and numerical study of the thermal performance of a parabolic solar trough collector. Arabian Journal for Science and Engineering. 2025:1-3.

[28] Nguyen TB, Paramasivam P. Model-prediction of efficiency of a parabolic trough collector using data-driven soft computing. International Journal on Computational Engineering. 2024; 1(1):1-8.

[29] Fahim T, Laouedj S, Abderrahmane A, Driss Z, Tag-eldin ES, Guedri K, et al. Numerical study of perforated obstacles effects on the performance of solar parabolic trough collector. Frontiers in Chemistry. 2023; 10:1-11.

[30] Chakraborty O, Das B, Algarni S, Alqahtani T, Irshad K. Numerical investigation of parabolic trough collectors using hybrid nanofluids and modified receiver tube. Applied Thermal Engineering. 2025:127597.

[31] Dudley VE, Workhoven RM. Performance testing of the aurex solar-collector model 3001-03. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); 1982.

[32] Gaul HW, Rabl A. Incidence angle modifier and average optical efficiency of parabolic trough collectors. National Renewable Energy Lab. (NREL), Golden, CO (United States); Solar Energy Research Institute (SERI), Golden, CO (United States); 1979.

[33] Jaramillo OA, Venegas-reyes E, Aguilar JO, Castrejón-garcía R, Sosa-montemayor F. Parabolic trough concentrators for low enthalpy processes. Renewable Energy. 2013; 60:529-39.

[34] Forristall R. Heat transfer analysis and modeling of a parabolic trough solar receiver implemented in engineering equation solver. National Renewable Energy Lab. (NREL), Golden, CO (United States); 2003.

[35] Kutscher C, Burkholder F, Netter J. Measuring the optical performance of evacuated receivers via an outdoor thermal transient test. National Renewable Energy Lab. (NREL), Golden, CO (United States); 2011.

[36] Wu S, Tang R, Wang C. Numerical calculation of the intercept factor for parabolic trough solar collector with secondary mirror. Energy. 2021; 233:121175.

[37] Bendt P, Rabl A, Gaul HW, Reed KA. Optical analysis and optimization of line focus solar collectors. Solar Energy Research Institute. (SERI), Golden, CO (United States); 1979.

[38] Tzivanidis C, Bellos E, Korres D, Antonopoulos KA, Mitsopoulos G. Thermal and optical efficiency investigation of a parabolic trough collector. Case Studies in Thermal Engineering. 2015; 6:226-37.

[39] Abed N, Afgan I, Iacovides H, Cioncolini A, Khurshid I, Nasser A. Thermal-hydraulic analysis of parabolic trough collectors using straight conical strip inserts with nanofluids. Nanomaterials. 2021; 11(4):1-30.

[40] https://www.therminol.com/sites/therminol/files/documents/TF09A_Therminol_VP1.pdf. Accessed 26 January 2026.

[41] Dudley VE, Kolb GJ, Mahoney AR, Mancini TR, Matthews CW, Sloan MI, et al. Test results: SEGS LS-2 solar collector. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); 1994.