Taking the Spanish power station model as the research object

six kinds of chimneys with different divergence angles are designed by changing the chimney outlet radius.Moreover

combined with the solar load model and the discrete coordinate radiation model

the performance and the optimal divergence angles of the solar chimney power plant system are studied by considering the real three-dimensional turbine operation.The results show that

the optimal divergence angle of the system is 2.0°.When the divergence angle of the chimney is 2.5°

the streamline in the chimney is disturbed

and boundary layer separation and reflux occur.At the same rotational speed of turbine

the pressure drop at the turbine increases with the chimney divergence angles

but the increase trend weakens gradually.Especially

when the chimney divergence angle is 2.5°

the turbine pressure drop is lower than that when the chimney divergence angle is 2.0°.When the chimney divergence angle is 2.0°

the maximum power output of the turbine is 64.15 kW

and the maximum system efficiency is 0.167%

which is 1.4 times higher than that when the chimney divergence angle is 0°.