Constructal Design of Available Power of a Solar Chimney at Different Imposed Ground Temperature
Rodrigo Spotorno Vieira1; Christopher Garcia1; Luiz Alberto Oliveira Rocha2; Liércio André Isoldi1; Elizaldo Domingues dos Santos1; Mateus das Neves Gomes Gomes3
1 Universidade Federal do Rio Grande; 2 Universidade Federal do Rio Grande do Sul; 3 Instituto Federal do Paraná
Baixar PDF doi:10.20906/CPS/CILAMCE2015-0368
Resumo
In the presented work, it is made a numerical study about the main physical principle of a solar chimney (SCPP - Solar Chimney Power Plant) and the influence of some geometric parameters on the available power in the SCPP. The numerical study is performed for different imposed ground temperatures, mimicking the effect of different radiative energy absorbed in device. Constructal Design is used to evaluate the problem geometry. The problem is submitted to three constraints: collector, turbine and chimney areas. Moreover, three degrees of freedom are taken into account: R1/H2 = 0.05 (ratio between the radius and height of chimney), H1/H = 10.0 (ratio between the height of collector base and collector inlet height) and R/H (ratio between the collector radius and collector inlet height) which is varied in the present work. The main objectives are to test the applicability of the studied numerical model in future studies of SCPP geometric optimization and to test the effect of the ground temperature in the collector on the available power of the device. For that it is considered an incompressible, turbulent, steady flow with mixed convective heat transfer in a two-dimensional and axisymmetric domain, similar to the one found in a solar chimney. The conservation equations of mass, momentum and energy are numerically solved using the finite volume method, more specifically with the FLUENTTM software. The time-averaged turbulence modeling (RANS) was used for the turbulence approach with standard model k - ε. For every studied cases, Constructal Design allowed the improvement of available power. For the worst performance the difference on the ground temperature has changed the available power almost 30%. Therefore, the ground temperature has a large sensibility in the available power.
Palavras-chave: Constructal design; Solar chimney; Numerical study