Solar Dish Concentrator: A Case Study at the Energy Center Rooftop

Abstract

Concentrating solar technology plays a role, albeit a niche role compared to commercial solar systems (photovoltaics and thermal collectors). Within the context of sustainable development and within the green transition phase, it could be a respectable player. The main purpose of this study is to create and validate a model that approximates the temperature trend of a receiver installed in a CSP (concentrated solar plant). A method to approximate optical and thermal performance is discussed. The paraboloid installed in the Energy Center (Turin, Italy) was taken as a reference, creating a model that could simulate real operating conditions. The Monte Carlo (MC) method for ray tracing was adopted developing two models. The first model sets the maximum reflectivity of the paraboloid and neglects the loss of “limb darkening,” while the second one sets a reflectivity of 80%. Once the incident flux was obtained, the optical performance was analytically calculated and compared to the value provided by the manufacturer. The thermal performance was also studied, reproducing the dimensions of the receiver consisting of a sintered alumina tube placed at a focal distance from the paraboloid. Two configurations were analyzed: one neglecting the losses due to radiation and natural convection, the other one including the losses due to radiation and considering the atmospheric wind condition. Finally, the model was validated by comparing the obtained temperatures with those measured by thermocouples placed on the receiver. Analyzing two random days in the year 2020, an average error of 7% and 2% was obtained.