The luminescent solar concentrator-based photomicroreactor (LSC-PM) is a novel technology applied to the synthesis of chemicals coupling the advantages of sunlight modulation/concentration and microflow chemistry. In this work, a virtual model of this device, based on computational fluid dynamics (CFD), was implemented. The CFD model was developed considering a kinetic law that takes into account the effect of light intensity on the reaction performance for the [4 + 2] cycloaddition of 9,10-diphenylanthracene, used as benchmark. Then, a feedforward control algorithm was implemented and the system's performance under different functional dependences of light intensity through time was investigated, being able to maintain the conversion at the desired level despite the power fluctuations. Thus, the CFD model was independently validated considering the control framework associated to the experimental data. Finally, the effect of varying some geometrical features of the photomicroreactor was investigated, highlighting the capability of using a computational model for engineering purposes (design and optimization). Therefore, this work represents a contribution toward a fully predictable model for the investigation of the performance and for the design and optimization of LSC-PMs in a variety of chemical processes.