Desenvolvimento de uma bancada de testes para avaliação do desempenho térmico de um concentrador Fresnel linear

Abstract

Among concentrators, linear Fresnel reflectors (LFR) have become an attractive solar power technology for being suitable for use in heating and cooling systems of buildings, domestic water heating and steam generation for industries. Conduction of performance tests is of great importance for the development and establishment of thermal solar concentrators. Existing standards prioritize testing for flat solar reflectors and show technical limitations in established methods for thermal performance analyses of concentrators. In this way, the development of test procedures is necessary, especially to characterize their linear optical performance throughout the year. Thus, the main purpose of this study is the development a test bench to experimentally, determine the thermal performance of a linear Fresnel concentrator. The collector used contains 14 rows of mirrors of 300 mm wide each, with a secondary concentrator with an opening of 300 mm, located 3 m high in relation to the plane containing the axes of the mirrors. Analyzes of existing methodologies and regulations were conducted to determine the performance of solar concentrators. Based on the existing standards, the test methodology and the necessary equipment to conduct the tests were defined. As a result of the tests, the collector efficiency curve and its performance parameters were obtained. The maximum efficiency approached 30% and maximum power reached was 6.25 kW. The optical analysis indicated the extremely high final losses on June 21, as only 30% of the absorber received the rays reflected by the mirrors.