Method for reducing deviation of flue gas velocity at furnace outlet of bi-tangential circle boiler based on over fire air

A method for reducing deviation of flue gas velocity at a furnace outlet of a bi-tangential circle boiler based on over fire air comprises the following steps of calculating the modeling wind velocityof primary and secondary air and the over fire air in a self-modeling zone at a flow field; testing the deviation of flue gas velocity at the furnace outlet when the over fire air is not supplied into the boiler; testing the deviation of the flue gas velocity when the over fire air is supplied into the boiler and both the horizontal and vertical directions of the over fire air are set to zero; testing the deviation of the flue gas velocity when the over fire air is supplied into the boiler and swings down; testing the deviation of the flue gas velocity when the over fire air is supplied intothe boiler and is reversely tangent; and obtaining the rule of influences of the over fire air on the deviation of the flue gas velocity at the furnace outlet of the bi-tangential circle boiler by combining the test results. T