The flexible DC valve hall of the Converter Station Project is 110 meters long and has a span of 65 meters. It is the valve hall with the largest span in the domestic converter station at present. The roof of the valve hall adopts steel space frame, which solves the problem of large span.
The steel space frame is a grid space structure composed of 16,115 rods connected by 3,556 nodes. It has the advantages of balanced space force, light weight, high stiffness, and good seismic performance.
The minimum height of the space frame itself is 4.275 meters, the maximum height is 7.7 meters, and the lower chord elevation of the space frame is 19.9 meters. The ceiling height is large and the construction is difficult.
The project department adopts the construction plan of ground assembly and the overall lifting of the space frame, and compiles special charts such as the space frame assembly and the installation flow chart of the jacking frame to clarify the workers to ensure that the construction process is correct. Before the space frame is assembled and constructed, the project department conducts precise positioning. Then expand the assembly from the center to the four sides on the ground.
Next, let me take you to understand the process of hydraulic jacking operation, the generator of hydraulic jacking frame, which is the beginning of the lifting construction process. The operation of hydraulic jacking is done through a computer. Professionally trained operators contact the construction personnel above the jacking frame after the steel space frame is jacked into place by the jacking frame. After the steel space frame was in place, the operator was instructed to continue to build the jacking frame. The project department sent additional experienced safety personnel to stay on the converter station construction site throughout the process to monitor high-altitude operations to ensure operation safety.