500kV outlet tunnel cable tray construction safety technical measures
I. construction environment
Xiaowan power station main transformer room and xiushangou third situation: at this time, push should be changed. 6. The experimental motor source should be reliably grounded; The frequency fluctuation shall not exceed 2% of the rated frequency. The angle between the plate and the contact surface of the toothed rod head is connected between the ground 500kV switchyard through two cable outlet inclined holes. The total length of the inclined tunnel for the outgoing line of No. 1 cable is about 539m from the cable layer of the main transformer room to the outlet of the switch building, in which three 500kV high-voltage outgoing dry-type cables of three units are laid, with a total of 9 cables. The total length of the inclined tunnel for the outgoing line of No. 2 cable is about 516m from the cable layer of the main transformer room to the outlet of the switch building, in which 3 sets of 500kV high-voltage outgoing dry-type cables with stable mechanical performance are laid, 3 circuits in total, 9. The section size of cable outlet tunnel is 4.5m wide and 4.5m high (to the arch foot). Other cables from the main power house to the switchyard are also laid through this cable outlet hole
II. Brief introduction to construction
there are lighting, high-voltage cable supports, low-voltage cable bridges in the 500kV outlet tunnel, and the growing use of polymer composites in the field of wind energy, as well as the installation of fire-fighting and ventilation systems. Due to the limited space in the tunnel, in order to ensure safe construction, cross operation is not used in the same construction section. Different construction is carried out according to different periods of time, and reasonable arrangements are made to improve work efficiency
the civil construction in the 500kV outlet tunnel has been completed, which is connected to the switch building upward and to the main transformer cable layer downward. Because the civil construction of the main transformer cable layer connected to the 500kV outlet tunnel has not been completed, the bottom of the outlet tunnel is in a suspended state. In order to ensure the safety of construction in the 500kV outlet tunnel, the bottom of the inclined tunnel must be blocked according to the actual site conditions to prevent people and objects from falling
III. main hazard sources and their control measures
identification of major hazard sources in construction and risk control measures
IV. safety production and civilized construction measures
1. The two 500kV outlet tunnels are inclined tunnels with a total length of more than 500 meters, and there is an exit in the middle to facilitate construction access. When entering the outlet tunnel for construction, the construction personnel must take protective measures, be equipped with a flashlight, and it is forbidden to play in the tunnel
2. Personnel of special types of work shall work with certificates, and safety education shall be carried out for construction personnel before construction
3. The construction is carried out in the tunnel more than 2.5 meters above the ground. In order to facilitate the construction, a construction platform is made according to the slope in the tunnel on site for the installation of cable tray. Because it belongs to high-altitude operation, it is not allowed to throw tools and instruments up and down during construction, high-altitude protection is done, and the construction platform is placed stably. When making the platform, the welding points should be firm and reliable, and meet the bearing requirements
4. The lighting in the tunnel is reliable, the lighting cable and the construction power line are well insulated, and the cable should be fixed on the tunnel wall. It is not allowed to lay along the tunnel bottom, and the wire core is not allowed to be exposed. Construction equipment and construction power supply shall be arranged orderly, and sporadic materials, tools and instruments shall be placed neatly
5. In order to avoid electric leakage and short circuit, electric tools and construction power lines should be maintained and checked frequently. During electric welding construction in the tunnel, the construction personnel shall take safety protection measures, all equipment shall be strictly grounded, and leakage protection devices shall be set in the distribution cabinet
6. Due to the limited space in the tunnel, large construction materials (bridges) are not allowed to be stacked in the tunnel in order not to hinder the construction
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