Abstract: The invention discloses a device for preheating before welding and post-welding heat treatment of tank. The device includes a first roller, two electric heating belts, calipers, a thermostat, two positioners and hinges. Both of the electric heating belts are arranged around the tank and distributed on both sides of the welded seam. A number of calipers are provided on both sides of each electric heating belt, one end of each caliper can operatively clamp the side of the electric heating belt, another end of each caliper is rotatably connected to a first roller. The hinge is connected to the electric heating belt, and one end of the hinge away from the electric heating belt is in a fixed state. The heating temperature of the electric heating belt is controlled, thereby realizing preheating of the tank before welding, heat preservation during welding and post-welding heat treatment without transferring.

Abstract: The invention discloses a device for preheating before welding and post-welding heat treatment of tank. The device includes a first roller, two electric heating belts, calipers, a thermostat, two positioners and hinges. Both of the electric heating belts are arranged around the tank and distributed on both sides of the welded seam. A number of calipers are provided on both sides of each electric heating belt, one end of each caliper can operatively clamp the side of the electric heating belt, another end of each caliper is rotatably connected to a first roller. The hinge is connected to the electric heating belt, and one end of the hinge away from the electric heating belt is in a fixed state. The heating temperature of the electric heating belt is controlled, thereby realizing preheating of the tank before welding, heat preservation during welding and post-welding heat treatment without transferring.

Abstract: A method of substation-control center two-level distributed modeling for power grid is provided. The method comprises: (1) building a substation model for each of substations, each substation model comprising a network model having a topological structure of the substation devices, parameters of the substation devices and measurement information of each substation devices, and a wiring diagram of each substation based on a whole line identification consistency; (2) uploading each substation model for each of the substations to the control center through a state power dispatching data network; and (3) splicing network models for the substations according to the wiring diagrams of the substations to build a whole power grid model of a whole power grid so as to monitor and control the whole power grid.