Boiler water-cooling wall lower collecting box and cold ash hopper connection sealing device

A boiler water-cooling wall lower collecting box and cold ash hopper connection sealing device comprises a connection sleeve which is vertically arranged and fixedly connected with the bottom of a water-cooling wall lower collecting box. The lower part of the outer side of the connection sleeve is vertically and fixedly connected with an upper sealing sleeve, and the top part of a cold ash hopper is vertically and fixedly connected with a lower sealing sleeve. The outer side of the lower end of the upper sealing sleeve and the inner side of the upper end of the lower sealing sleeve are overlapped movably. The outer side of the upper sealing sleeve is horizontally and fixedly connected with a first annular baffle plate, and the outer side of the lower sealing sleeve is horizontally and fixedly connected with a second annular baffle plate. A thermal insulation layer is arranged between the first and second annular baffle plates in the outer side of the upper and lower sealing sleeves. With the aforementioned sc