Fluid groove preheating cover plate and fluid groove preheating method

The invention relates to a fluid groove preheating cover plate and a fluid groove preheating method. The fluid groove cover plate is provided with a board frame formed by welding angle iron. A ceramic fiber board is nested into the board frame. The fluid groove preheating method includes the steps that a fluid groove is covered by the fluid groove cover plate, and natural gas is burned in the fluid groove through a fire gun barrel so as to heat the fluid groove. The fluid groove preheating cover plate and the fluid groove preheating method have the advantages that silicic acid cotton is not needed, the quality of cast ingots can be improved, occupational hazards are reduced, the natural gas can be less used, energy is saved, and emission is reduced; the fluid groove can be more evenly heated; problems like deformation and cracking of the fluid groove are avoided.