Analysis and mitigation of erosion wear of transfer ducts in a falling particle CSP system

Abstract

Solid particles are effective heat capture and transfer media for next-generation (Gen3) concentrating solar power (CSP) plants that offer high-temperature operability, lower levelized cost, and higher efficiency. However, the relative motion of the solid particles with respect to the CSP system components causes significant wear of the wall materials in the form of erosion and abrasion. The transfer duct is one of the prevalent components in the falling particle CSP system that experiences erosion wear due to the impact of particles on its surface, which depends on several factors, such as duct design, material, and particle flow rate, among others. In this work, erosion wear in the transfer duct and its mitigation were studied computationally through different duct designs and particle flow parameters, including transfer duct length, diameter, slanted angle of the duct, and entrance velocity. Computational simulations based on particle tracking and discrete element modeling were used to understand erosion behavior systematically and, in turn, identify areas most prone to erosive wear. It was found that the use of erosion-resistant coatings in selected locations determined from the simulations was sufficient to mitigate overall erosion wear in the component. This study provides fundamental insight into the erosion wear of a key component of the falling particle CSP system for the first time and the design approaches to mitigate wear.