The invention discloses a circumferentially graded low-
pollution combustion chamber with multiple middle spiral-flow
flame stabilizing stages. The
combustion chamber has a single annular cavity structure; a low-
pollution combustion organization mode in which air grading is matched with
fuel oil grading is adopted; all
fuel gas is supplied by a duty stage, a middle stage and a main combustion stage; and
fuel oil grading supply proportion is controlled accurately according to the operating condition of an engine and the requirement on stable low-
pollution combustion. The duty stage has a combined structure in which two-stage axial
spiral flow is matched with a venturi tube, and a formed low-speed
reflux region can support stable combustion of the
combustion chamber; the middle stage has a combined structure in which a plurality of single-stage axial
spiral flow circumferentially and uniformly distributed on the same circumference in the same axial cross section are matched with the venturi tube, and a formed middle
flame stabilizing stage combustion region is used for intensifying and stabilizing
flame in the main combustion stage; and the main combustion stage has a combined structure in which a plurality of single-stage axial
spiral flow circumferentially and uniformly distributed on the same circumference in the same axial cross section are matched with the venturi tube, so that an oil and gas mixed poor-oil premixing and pre-
evaporation combustion mode is intensified and the emission of pollutants is further reduced greatly.