Transient Characterization of Multiple Parabolic Trough Collector Loops in a 100 MW CSP Plant for Solar Energy Harvesting

Abstract

Parabolic trough solar collection technology has been widely deployed in concentrated solar power (CSP) generation plants all over the world. In a large-scale CSP plant, a solar field consists of hundreds of parabolic solar collector loops. Due to the parallel loop arrangement (Fig. 1) and non-unifoum solar collection, mal-distributions of heat-transfer-fluid flow (HTF, synthetic oil) among different loops commonly occur during transient operation. Many solar collector loops have to be pushed out of tracking phase to avoid oil overheating and degradation, which causes significant loss in solar energy collection and power generation. Such collector defocusing and refocusing operation results in large transient variation of HTF temperature, which further brings challenges to energy-efficient operation and maintenance of the coupled thermal power generation unit. Advanced transient analysis, control and fault diagnosis tools are desired to achieve safer CSP plant operation and transient solar power harvesting. In this paper, a distributed transient optical-thermal-fluid model of parabolic trough collector is developed and validated with field data from a 100MW th CSP plant. Transient model predictions are in fair agreement with experimental field data, which provide a quantitative tool for solar energy harvesting. Conceptual active flow control strategies are further introduced to regulate the HTF temperature and maintain high solar collection efficiency.

Establishment, Validation, and Application of a Comprehensive Thermal Hydraulic Model for a Parabolic Trough Solar Field

“…Refs. [14] and [20] indicated that the loop control valves (LCVs) have the potential to improve the PTSF performance. However, the lack of a refined model increases the difficulty of calculating the valves opening and simulating the PTSF characteristics under varied solar irradiance.…”

Optimal Operation Strategies into Deregulated Markets for 50 MWe Parabolic Trough Solar Thermal Power Plants with Thermal Storage

“…The use of efficient technologies that minimize layout spaces has a significant impact on the performance and loss coefficients of the final installation. As shown in [9], the low uniformity of solar capture in the field, due to different parameters and meteorology, makes it necessary for collectors to use partial blurs or loops that increase the transient effect of solar capture, making the operation of the real PT plant more difficult. Likewise, it is necessary to know the actual absorption conditions in large loops of collectors with an exhaustive control of the temperature of each component in the loop [10].…”

“…The total production variation of the plant is obtained through (9). This value is proportional to the absolute value of the electric power variation generated along two sequential hours [26].…”

Optimization of 100 MWe Parabolic-Trough Solar-Thermal Power Plants Under Regulated and Deregulated Electricity Market Conditions

“…Nevertheless, data relating to investment returns regarding the implementation and maintenance costs of the solar field are directly related to the use of TES [8]. The low uniformity of solar capture of the field, due to different parameters and meteorology, makes the use of partial blurs by collectors necessary that increase the transient effect of solar collection, hindering plant operation [35]. Thus, TES systems offer the possibility to provide reliable electricity that can be dispatched to the grid when needed, including after sunset to match late-evening peak demands, or even around the clock to meet base-load demands [28,36].…”