Market-Oriented Flow Allocation for Thermal Solar Plants: An Auction-Based Methodology with Artificial Intelligence

TL;DR

The study tackles thermal imbalance in parabolic trough solar plants under uncertain loop losses and irradiance by introducing a two-layer control: an auction-based flow allocation across loops and an artificial neural network to emulate the auction decisions for real-time operation. It validates the approach on both concentrated-parameter and distributed-parameter plant models and demonstrates improved thermal power and intercept factors compared with equal-flow baselines across sunny, partially cloudy, and cloudy conditions. The method is then demonstrated on a realistic 50 MW installation and subsequently deployed in 13 commercial solar trough plants, highlighting scalability and practical deployability with reduced data requirements. Overall, the auction-based mechanism coupled with an ANN achieves robust performance gains while remaining computationally light enough for real-world plant DCS integration, making it a viable path toward enhanced efficiency in large-scale CSP.

Abstract

This paper presents a novel method to optimize thermal balance in parabolic trough collector (PTC) plants. It uses a market-based system to distribute flow among loops combined with an artificial neural network (ANN) to reduce computation and data requirements. This auction-based approach balances loop temperatures, accommodating varying thermal losses and collector efficiencies. Validation across different thermal losses, optical efficiencies, and irradiance conditions-sunny, partially cloudy, and cloudy-show improved thermal power output and intercept factors compared to a no-allocation system. It demonstrates scalability and practicality for large solar thermal plants, enhancing overall performance. The method was first validated through simulations on a realistic solar plant model, then adapted and successfully tested in a 50 MW solar trough plant, demonstrating its advantages. Furthermore, the algorithms have been implemented, commissioned, and are currently operating in 13 commercial solar trough plants.

Figures (9)

• Figure 1: General scheme of a PTC plant.
• Figure 2: Efficiency-defocus angle curve of the collectors in a PTC plant sanchez2020DefocusingPTC.
• Figure 3: Temperatures, flow rates, intercept factors and thermal powers obtained without allocation and with the first allocation method by simulation of the static model with the first test profile.
• Figure 4: Temperatures, flow rates, intercept factors and thermal powers obtained without allocation and with the first allocation method by simulation of the static model with the second test profile.
• Figure 5: Temperatures, flow rates, intercept factors and thermal powers obtained without allocation and with the first allocation method by simulation of the static model with the third test profile.