What is the relationship between the furnace size and low nitrogen combustion of gas-fired boiler?

Boiler furnace is a three-dimensional space surrounded by furnace walls, which is used for burning fuel. The function of the boiler furnace is to ensure that fuel is burned out as much as possible, and to cool the flue gas temperature at the outlet of the furnace to the temperature allowed by the safe operation of the convection heating surface. Therefore, the furnace of the boiler should have enough volume to arrange enough heating surfaces. In addition, the furnace should have a reasonable shape and size, to cooperate with the burner and organize the aerodynamic field in the furnace, so that the flame will not stick to the wall, or flush the wall, and will have a high degree of fullness and uniform heat load on the wall.