Study of heat distribution in penstock pipes due to solar radiation case study of Chaglla Hydropower Plant

Arias B.; Alvarez W.; Xilai Y.; Jun Y. · 2025 25th Conference of the Electric Power Supply Industry, CEPSI 2025 (2025) · DOI: 10.1109/cepsi66359.2025.11403655

Resumen

Chaglla Hydropower Plant, featuring two Francis turbines rated at 230.70 MW each, utilizes penstock pipes to convey water from the valve house to the turbines. Routine maintenance inspections have identified persistent water leakage at the expansion joint, prompting an investigation into the impact of potential thermal-induced misalignments. This study aims to analyze how solar radiation affects temperature variations and the subsequent structural behavior of the penstock pipes, with a particular focus on their expansion and contraction phenomena.By utilizing both thermographic measurements and dimensional analysis, circumferential temperature distribution and its effects on the lateral displacement of the pipes are evaluated. Empirical data collected from multiple inspections were analyzed alongside established thermal deformation models applicable to exposed penstocks. Preliminary findings indicate that non-uniform temperature distribution leads to differential expansion, leading to misalignment and pressure imbalances at the expansion joint, thereby contributing to leakage.Furthermore, by identifying the relationship between solar radiation, thermal expansion, and mechanical stress on penstock pipes infrastructures, this research serves as a basis for optimizing maintenance strategies and enhancing structural designs in hydropower facilities. The implications of these findings contribute to improved reliability of plant operations, reduced water loss, and a general increase in efficiency across hydropower facilities.