Full-premixing low-nitrogen combustor with adjustable end cover

The invention discloses a full-premixing low-nitrogen burner with an adjustable end cover, and belongs to the technical field of burners, the full-premixing low-nitrogen burner comprises an air channel and a gas ring cavity coaxially arranged with the air channel, the air channel is sequentially connected with a contraction cylinder and a straight flame cylinder, the contraction cylinder is in a conical barrel contraction shape, the upstream is connected with the air channel, and the downstream is connected with the straight flame cylinder; the downstream of the straight flame tube is connected with a flame end cover, the contraction tube, the straight flame tube, the flame end cover and the air channel are coaxially arranged, the lower portion of the air channel is connected with a main gas pipeline, a plurality of gas branch pipes which are evenly distributed are arranged in the air channel, the centripetal ends of the gas branch pipes are closed, and the eccentric ends of the gas branch pipes are connected