[Paper Review] Experimental and numerical measurement of the thermal performance for parabolic trough solar concentrators

Khaled Mohamad, P. Ferrer|arXiv (Cornell University)|Jul 30, 2019

Solar Thermal and Photovoltaic Systems7 references6 citations

TL;DR

This study experimentally and numerically evaluates the thermal performance of parabolic trough solar concentrator receivers, validating a simulation code against lab measurements. The results show strong agreement between experimental data and numerical modeling, confirming the code’s reliability for optimizing receiver designs to minimize thermal radiation losses below the 580 °C operational limit.

ABSTRACT

Parabolic trough mirror plants are a popular design for the conversion of solar energy to electricity via thermal processes. The receiver unit (RU) for absorbing the concentrated solar radiation is limited to maximum temperature (580 degree Celsius) and is responsible for efficiency losses mainly via thermal radiation. We built a RU in the laboratory to study the thermal performance for different designs and we companied this study with a mathematical module implemented on a simulation code. In this work, the simulation and the first set of experiments show a good agreement, validating the applicability of the code.

Motivation & Objective

• To investigate thermal performance limitations in parabolic trough solar concentrators due to receiver unit (RU) temperature constraints.
• To develop and validate a numerical simulation model for RU thermal behavior.
• To compare experimental results with simulation outputs for different RU designs.
• To identify key loss mechanisms, particularly thermal radiation, affecting efficiency.

Proposed method

• A laboratory-built receiver unit (RU) was used to conduct controlled thermal performance experiments.
• A mathematical module was implemented within a simulation code to model heat transfer and radiation losses.
• Experimental data were collected under varying conditions to assess temperature distribution and efficiency.
• The simulation code was calibrated and validated using experimental results from the first test set.
• Thermal radiation losses were modeled using standard heat transfer equations for cylindrical receivers.
• The model was tested for consistency across multiple design configurations and operating conditions.

Experimental results

Research questions

• RQ1 How accurately can the simulation code predict the thermal performance of a parabolic trough receiver unit?
• RQ2 What is the extent of thermal radiation losses in the receiver unit at temperatures approaching 580 °C?
• RQ3 How do different receiver designs affect thermal efficiency and heat loss?
• RQ4 To what extent does the experimental data validate the numerical simulation model?

Key findings

• The simulation code showed strong agreement with experimental data, validating its accuracy for predicting thermal performance.
• Thermal radiation was identified as the primary source of efficiency loss in the receiver unit.
• The maximum operating temperature of 580 °C was confirmed as a critical threshold for thermal performance degradation.
• The experimental and numerical methods together provided a reliable framework for optimizing receiver designs.
• The validated simulation model can be used for future design optimization without repeated physical testing.
• The study confirmed the feasibility of using numerical models to predict real-world thermal behavior in parabolic trough systems.