The study performs a numerical simulation analysis of the thermal performance and pressure loss penalty in a rectangular channel with dual grooves. The configurations of periodic dual grooves with different widths are proposed to enhance thermal performance. The flow structure, the heat transfer characteristic, the pressure loss penalty, and the thermal performance index of the rectangular channel are researched at Reynolds numbers spanned from 8000 to 16,000. Three different width-to-channel hydraulic diameter ratio(W/d) of the dual groove are considered: 0.15, 0.2, and 0.25. The results indicate that the size of the recirculation flow within the dual grooves increases with the increasing dual groove width, and therefore the low-momentum flow region exhibits progressive expansion. The single groove configuration yields the lowest averaged Nusselt numbers, pressure loss penalty, and thermal performance index. With the increase of Reynolds numbers from 8,000 to 16,000, the averaged Nusselt numbers increase, while the pressure loss coefficients and the thermal - performance index decrease. The averaged Nusselt numbers and thermal performance index for the dual groove channel with W/d of 0.15 are lower than that for the dual groove channel with W/d of 0.2 and 0.25 at low Reynolds number. The averaged Nusselt numbers and thermal performance index for the dual groove channel with W/d of 0.15 are the highest in high Reynolds numbers. In the dual groove channel with the W/d of 0.2 and 0.25, the decrease rate of the pressure loss coefficients is less than that observed in the W/d of 0.15. The three cases being almost the same when the Reynolds number reaches 16,000.